P-506 Administration of low molecular weight heparin alleviate immune physiology in recurrent implantation failure modulating CCL2-CCR2 axis during frozen embryo transfer: effort from clinic to bench

Study question

Does low molecular-weight heparin (LMWH) administration modulate CCL2-CCR2 axis in recurrent implantation failure (RIF) patients undergoing frozen embryo transfer (FET) to improve pregnancy salvage?

Summary answer

LMWH treatment attests beneficial immunological tolerance in vivo and in vitro through modulation of CCL2-CCR2 axis suggesting possible restoration of weak pro-inflammatory response in RIF.

What is known already

Immune imbalance in proportion of activated macrophages (M1) and alternatively activated macrophages (M2) impede endometrial receptivity and contribute to RIF. CCL2 (M2-asscociated) - CCR2 (t-helper-2 associated) axis orders macrophage polarization by influencing expression of functionally relevant and polarization associated genes and down-modulate pro-inflammatory cytokine production. Immunological effects of LMWH regulate pregnancy-promoting processes at foetal-maternal interface to provide an appropriate implantation process; outcomes being controversial. We aim to investigate the potential immunoregulatory properties of LMWH in patients with RIF undergoing FET, with particular regard to effects on macrophages and T-helper (Th) cells; two key players in promoting immune tolerance during pregnancy.

Study design, size, duration

This prospective cohort study constituted 121 women with RIF (≥3 failed embryo transfer) undergoing FET at Institute of Reproductive Medicine between January to October 2022. An incremental dose (4-12mg/day) of estradiol with (Group A; n = 62) or without (Group B; n = 59) LMWH (40 mg/day) from d2 to d12 with sequential ultrasound following intra-muscular progesterone (100mg/day) for 4 days was administered in all participants. Blood samples were collected to isolate plasma and peripheral-blood-mononuclear-cells (PBMCs).

Participants/materials, setting, methods

Monocytes were purified from PBMCs and cultured with GM-CSF or M-CSF to analyze factor/s which control CCL2-CCR2 expression along macrophage polarization by flow cytometry. Influence of CCL2 on GM-CSF-cultured macrophages (GM-MØ) and M-CSF-cultured macrophages (M-MØ) specific gene markers was analysed using quantitative RT-PCR (qRT-PCR). To assess immunological effects of LMWH in-vivo, Th-specific cytokine profile/s and respective chemokines were measured from plasma by Luminex xMAP technology. Statistical significance was set at p < 0.05.

Main results and the role of chance

The clinical pregnancy rate was higher in group A. (A vs B: 37.09% vs. 27.11%, p = 0.24). LMWH exposure significantly decreased the secretion of CCL2 (p < 0.01) and CCL22 (p < 0.001) in GM-CSF-cultured macrophages, while it increased CCL2, CCL20 production (p < 0.001) in both GM-MØ and M-MØ. However, expression of CCL7 was significantly lower (p < 0.01) in M-MØ and GM-MØ generated from CD14+ CD16+ monocytes and CD14 ++ CD16- monocytes respectively under LMWH exposure. qPCR analysis revealed a significant increase (p < 0.01) in the expression of various GM-MØ–specific genes including EGLN3, and SERPINE1 in macrophage supernatant post LMWH treatment. Expression of various M-MØ-specific marker/s such as IGF1, FOLR2, and HTR2B, is significantly up-regulated (p < 0.01) in Group B. Group A, although documented a decreased concentration/s (pg/ml) of Th17-type cytokine/s (IL-6 (1.88 ± 0.65 vs. 0.91 ± 0.43; p < 0.04 and IL-23 (17.94 ± 9.76 vs. 7.78 ± 3.43; p < 0.01)), at end of treatment, concentration of TGF-β was significantly higher (3909.05 ± 1248.35 vs. 2469.83 ± 1058.71; p < 0.01) which cue to probable maintenance in balance of inflammatory response at the time of implantation. No differences were observed in Th1-type cytokine level/s (IFN-γ and TNF-α). CXCL10, CXCL11, CXCL1, CXCL8, CCL17, CCL22 do not differ in vivo.

Limitations, reasons for caution

Beneficial effects of LMWH administration with a good sample size are clearly needed to confirm this hypothesis; hence result/s should be dealt with caution. Further to this, inclusion of other arm/s (corticosteroids, intralipid and/or intravenous immunoglobulin) will make the study much robust and conclusive.

Wider implications of the findings

The identification of atypical Th1-associated pro-inflammatory effects of LMWH drives to evaluate modulation of CCL2 expression to limit or potentiate macrophage activation in RIF; especially where anticoagulant effect is not the primary goal. Further, modification of cytokine expression/s might potentiate novel strategy derived from deregulated macrophage polarization.

Trial registration number

Not Applicable

P-336 Presence of stage III/IV endometriosis associated with systemic inflammation poses as individual risk factor for coronary heart disease in Indian women: Inklings for the search

Study question

Can investigating endometriosis—cardiovascular interaction identify women with stage III/IV endometriosis and elucidate pathophysiology of the female heart at a broader level?

Summary answer

Endothelial dysfunction can occur in absence of structural atherosclerotic changes in young Indian women with endometriosis urging lifelong multidisciplinary care to manage long-term health impact.

What is known already

Chronic inflammation, enhanced oxidative stress, endothelial dysfunction, and cellular proliferation are hallmarks of both atherosclerosis and endometriosis with unveiled cellular and molecular overlaps between the duos. Further, treatment/s of endometriosis, like, hysterectomy or oophorectomy and/or analgesics confer increased risk of coronary heart disease (CHD) to women with endometriosis. However, CHD in women with endometriosis remains understudied, under-recognized, and underdiagnosed. Incidentally, early atherosclerosis cannot be explained exclusively by traditional cardiovascular risk factors. Aim of the present study was to correlate subclinical atherosclerosis with metabolic parameters and markers of endothelial inflammation in Indian women with stage III/IV endometriosis.

Study design, size, duration

This observational prospective cohort study constituted 1407 consented women diagnosed with laparoscopically confirmed endometriosis (Group A; n = 718) with age matched control (Group B; n = 689) (counterpart/s of male infertility) from October 2021 to September 2022. Sub-clinical atherosclerosis was investigated before laparoscopy by ultrasound evaluation of carotid intima-media thickness (cIMT) and flow-mediated dilation (FMD). Serum samples were stored at -80 °C for evaluation of biochemical and inflammatory parameters. European Society of Cardiology guidelines were followed for standard definition/s.

Participants/materials, setting, methods

Traditional (obesity, hypertension) and metabolic (dyslipidaemia, diabetes, hyperhomocysteinemia) cardiovascular risk factor/s were assessed during evaluation and chemiluminescence respectively. Serum levels of interleukin (IL)-6, IL-8, IL-10, TNF-a, VEGF, and VCAM-1 were determined by enzyme-linked-immunosorbent assay/s. Univariate comparisons and bivariate correlations were conducted by Student’s t-test, and Spearman correlation respectively. Adjusted relative risks (aRR) with 95% confidence intervals (CI) were calculated by Cox-proportional hazard/s model among Group A vs Group B. Statistical significance was set at p < 0.05.

Main results and the role of chance

62.95% and 37.04% women had stage III and stage IV endometriosis respectively as defined according to European Society for Human Reproduction and Embryology 2014 guideline. aRR (adjusted for demographic, obesity, diabetes mellitus, reproductive history, and migraine), documented a higher risk of hypertension (aRR 1.43; 95%CI 1.33–1.54) in women with endometriosis. On stratification of group A in less than and more than 40 years, laboratory parameters were similar except for significantly higher (p < 0.01) serum values of homocysteine, low density lipoprotein and cholesterol, in both age range of group A. FMD, indirect marker of endothelial dysfunction, was found to be lower in group A compared to controls (mean difference: −7.54, 95% CI: -10.32− -4.73; p< 0.001, however, cIMT was similar between both cohort/s. aRR of endometriosis in relation with hypercholesterolemia (1.07; 95%CI 1.01–1.25; p < 0.001), hypertension (1.22; 95%CI 1.14–1.30; p < 0.001), and hyperhomocysteinemia (1.04; 95%CI 0.96–1.12; p < 0.08) decreased with increasing age (>40 years). Systemic inflammation markers, showed an inverse relationship (p < 0.001) between values of FMD and serum levels of IL-6 (r = –0.34), TNF-a (r = –0.85), and VCAM-1 (r = –0.28) in group A. Other correlations were not statistically significant.

Limitations, reasons for caution

This observational study is not supported by patients with typical cardiovascular risk factors and hence limits generalizability of evidence to other ethnicities. Further, no information on hormonal treatments, such as dianogest (a synthetic progesterone) and/or leuprolide (gonadotropin-releasing hormone analog) are available to assess extent of association between endometriosis and CHD.

Wider implications of the findings

Higher propensity of subclinical atherosclerosis in younger women with laparoscopically-confirmed endometriosis represent higher systemic inflammation cueing to increased risk for CHD. This suggests the need for risk awareness and subsequent screening for CHD and healthy lifestyle promotion among gynaecologist/s and public health specialists.

Trial registration number

Not applicable

O-097 Predicting live birth rate using combined Day3-spent embryo culture medium metabolomics and cumulus cell gene expression based algorithm to optimize embryo selection in unexplained infertility

Study question

Can combination of metabolomics of spent embryo culture medium (sECM) and cumulus cell (CC) genes judge live birth rate in unexplained infertility (UI)?

Summary answer

A combination of day3 metabolic profiling of sECM with CC gene expression yields an algorithm to predict live birth rate in UI.

What is known already

Optimizing embryo selection is rate-limiting for pregnancy success. The metabolomic profile of sECM can aid in advanced prediction of embryonic developmental potential. Recent transcriptomics studies proposed prokinectin 2 (PROK2), and pregnancy up-regulated nonubiquitous CaM kinase (PNCK) as two novel gene/s responsible for perifollicular vascularization and embryonic development respectively; two important events regulating bidirectional CC-oocyte signalling and implantation ability. Given that UI is contributory to impaired oocyte quality, we delineated if combined metabolic signature of CC gene expression encompassing metabolic, developmental competence, and extracellular matrix facet/s and sECM could address live birth rate in women with UI following single embryo transfer.

Study design, size, duration

A prospective cohort study was conducted at Institute of Reproductive Medicine between January 2022 and October 2022. 48 women (age: 30-39 years) diagnosed with UI undergoing oocyte-retrieval offered consented participation and were sub-stratified according to pregnancy outcome. Cleavage-stage embryos from intra cytoplasmic sperm injection (ICSI) cycles were scored according to combination of gene expression pattern of CC-samples and integral value of metabolite obtained from nuclear magnetic resonance (NMR) spectroscopy of sECM (range 0-3, 4-6, 7-9).

Participants/materials, setting, methods

Expression profiles of metabolic (LDHA, PFKP, PKM2), extracellular matrix (HAS2, PTX3, TNFAIP6, VCAN), and developmental competence (PNCK, PROK2) related genes were evaluated by real time-quantitative polymerase-chain-reaction (qRT-PCR) from retrieved CC. Day-3 sECM (30 μL) was collected for NMR from 43 single transferred embryos. Univariate and multivariate analysis was performed after NMR data acquisition. Live birth rate was evaluated by area-under-the-curve (AUC) values using combined score panel.

Main results and the role of chance

The groups were similar for patient age, BMI, AMH, infertility diagnosis, and stimulation protocol. A total of 43 cycles were included in the analysis [embryo transfer cancelled (n = 2), insufficient cumulus mass (n = 3)]. Clinical pregnancy was confirmed in 16 patients (37.21%). Mean mRNA levels for all genes were similar in CC associated with oocyte that fertilized normally (2PN) compared with those that either failed to fertilize or were abnormal (i.e. 1PN, 3PN). Similar results were observed in terms of speed of embryonic cleavage (≥7 cell on Day 3 vs. ≤6 cell on Day 3). Expression of VCAN, (OR: 1.102, 95% CI: 1.010-1.202, p < 0.02), PNCK (OR: 0.931, 95% CI: 0.916-0.947, p < 0.001) and PROK2 (OR: 1.273, 95% CI: 1.011-1.231, p < 0.001) was significantly higher (p < 0.01) in CC that achieved live birth compared with those that failed to result a successful pregnancy. Multivariate and univariate analysis revealed distinct metabolomic signatures between pregnant and non- pregnant group/s. Lactate, pyruvate and proline were the most significant (p < 0.01) altered metabolite in sECM of non-pregnant group when compared to their pregnant counterpart. The combination demonstrated a “good” (VCAN, pyruvate: AUC: 0.87), “fair” (PROK2, proline: AUC: 0.79) and “modest” (PNCK, glucose: AUC: 0.71) in terms of live-birth rate.

Limitations, reasons for caution

The study population is heterogeneous in terms of duration of infertility and previous infertility treatment outcome, limited by small sample size and subjective nature of embryo scoring. The presumable involvement of unknown factors in developmental competence of UI and impact of frozen cycle/s should also be addressed.

Wider implications of the findings

The study provides reliable accuracy measures to support relationship between live birth rate and combined score panel in patients with UI. It is envisioned integration of CC gene expression/s and metabolomics of sECM if combined with patient characteristics may tailor therapy by artificial intelligence to model the outcome in UI.

Trial registration number

Not applicable

P-324 Effectiveness of letrozole in symptomatic women with adenomyosis undergoing IVF: An overview of clinical features, sonographic characteristics, and reproductive outcome

Study question

Is letrozole pre-treatment a cost-effective option in improving symptoms, sonographic features, and reproductive outcomes in women with adenomyosis, undergoing IVF treatment?

Summary answer

Only two months of low dose letrozole pre-treatment is as effective as GnRH-agonist in symptomatic adenomyosis while significantly reducing the cost of treatment.

What is known already

About 20%–25% of women undergoing IVF present with adenomyosis and many of them suffer from dysmenorrhea and menorrhagia. Adenomyosis is often underdiagnosed and neglected uterine pathology which has a major bearing on the quality of life and fertility. Since adenomyosis is an estrogen-dependent disorder, letrozole, an aromatase inhibitor (controls estrogen production) is reported to be effective in improving symptoms of adenomyosis similar to GnRH-agonist but its role as before treatment IVF is unclear. Although GnRH-agonist is an established and effective pre-treatment option, is expensive and comes with the concerns like menopausal symptoms, increased gonadotropin doses, and duration of stimulation.

Study design, size, duration

This longitudinal, randomized cohort study was conducted at a tertiary-care hospital during June-2019 and November-2021. 194 adenomyosis women with symptoms undergoing fresh-cycle IVF, were screened and 147 recruited. These women were resistant to OCPs/progestins for symptomatic relief. 72 patients were treated with letrozole and 75 with GnRH-agonist for 2 months, and changes in their sonographic features and symptoms were evaluated before and after treatment. Reproductive outcomes were also compared between the treatment groups after IVF.

Participants/materials, setting, methods

Adenomyosis was diagnosed on 2D-TVS according to MUSA criteria. Among them, 72 patients were treated with 2.5 mg letrozole (only thrice weekly instead of conventional 2.5mg/daily) and 75 women were treated with GnRH-agonist depot (3.6mg/month) for 2 months. Patients were evaluated before and after 2 months of treatment for improvements in dysmenorrhea (VAS score) and menorrhagia (PBAC score), and quantitative scoring of sonographic features. Reproductive outcomes were also compared after both treatment.

Main results and the role of chance

The majority of women had 3-4 sonographic criteria on TVS (median of 3), such as irregular or interrupted junctional zone (79.49%), asymmetrical thickening of the myometrium (71.15%), globular uterus (43.59%), and myometrial cyst (33.33%). Significant reductions in the sonographic severity scores for diffuse adenomyosis, adenomyoma, and asymmetry in myometrial thickness were observed following both the treatment (p < 0.05). The effects of both the treatments were comparable in terms of severity of sonographic features (p > 0.05). Significant decreases in dysmenorrhea (letrozole: pre-7.76±1.6, post-1.74±0.58; GnRH-agonist: pre-7.92±2.1, post-0) and menorrhagia (letrozole: pre-169±31, post-73±18; GnRH-agonist: pre-171±25, post-12±6) were observed after 2 months in both the treatment (p < 0.05). Since GnRH-agonist treated women experienced cessation of menstruation, the VAS and PBAC scores were not directly comparable between the groups after treatment. All fresh cycle IVF women were included to understand the effect of pre-treatment of these women. Following fresh cycle IVF, clinical pregnancy (23.61%, 25.33%), miscarriage rate (35.29%, 36.84%), and live birth rate (12.5%, 13.33%), respectively for letrozole and GnRH-agonist groups were comparable (p > 0.05). The cost of the treatment was 19 times less with letrozole pre-treatment when compared with GnRH-agonist, while a comparable reduction in symptoms and IVF outcome parameters were observed.

Limitations, reasons for caution

A possible limitation is the lack of a proper blinding due to different routes of administration of the therapies. In the absence of a standardized classification of severity, we have used the TVS based scoring proposed by Lazzeri et al (2018), which is not universally accepted or independently validated.

Wider implications of the findings

Low-dose letrozole pre-treatment for 2 months is an attractive option before IVF for symptoms relief and comparable reproductive outcome to that of GnRH-agonist but with lower cost and without over-suppression of pituitary. This protocol may also be extended to women in general who are suffering from symptomatic adenomyosis.

Trial registration number

CTRI/2019/01/016919 [04/01/2019]

P-307 Mapping the uterine pathologies in endometrium: differential genetic interactions set the algorithm for improved diagnosis in women with adenomyosis

Study question

Do genetic components and functional annotation/s in eutopic endometrium share significant difference to influence diagnosis in adenomyosis?

Summary answer

An integrated clinico-transcriptomic approach chalk the chief individual as well as hub genes in women with adenomyosis to set the algorithm for improved diagnosis.

What is known already

Adenomyosis often document similar presentation/s to other gynecological diseases including endometriosis making the diagnosis difficult. Differentially expressed transcripts and proteins were identified by transcriptomic analysis and genome-wide profiling of eutopic and ectopic endometrial samples in women with endometriosis. Biological networking and functional enrichment analysis enable prioritization of candidate genes for validation purpose in target tissue. Recently, key pathways in proliferative stage of adenomyosis at transcriptome level were documented in eutopic endometrium. However, characterization of functional annotations may assist clinicians to evaluate if they share systematic correlations predictive of ultrasonographic finding/s for help in everyday practice in diagnosing adenomyosis .

Study design, size, duration

Microarray datasets (GSE7307 and GSE78851) were selected from Gene Expression Omnibus database (GEO), which contains endometriosis, adenomyosis and normal endometrial tissues. An in-depth bioinformatic analysis was done to determine differentially expressed genes (DEGs) on GEO2R platform; followed by gene ontology (GO), KEGG pathway enrichment and protein-protein interaction (PPI) analysis by DAVID (http://david.ncifcrf.gov) and Cytoscape (version 3.8.2) respectively. PPI network was predicted further using a search tool, STRING (http://string-db.org; version 11.0) for retrieval of interacting genes.

Participants/materials, setting, methods

Eutopic endometrial samples were obtained during window of implantation from women (n = 10) with endometriosis, adenomyosis and adenomyosis-associated-endometriosis as diagnosed by laparoscopy, and, trans-vaginal ultrasound (TVUS) between March to December 2021 from Institute of Reproductive Medicine, Kolkata. Counterpart/s of male sub-fertility, defined by World-Health-Organization criteria (5th edition) was treated as control (n = 10). In-silico findings were validated by quantitative-real-time PCR (qRT-PCR). TVUS findings and gene expression/s were correlated by Spermann-rank correlation test. P < 0.05 was considered statistically significant.

Main results and the role of chance

A total of 4474 and 1061, significant DEGs (log fold-change>1, p < 0.05) were identified from datasets of endometriosis and adenomyosis respectively. GO function/s included common biological processes and molecular function/s, namely, epithelial-to-mesenchymal transition (EMT), metallopeptidase activity and extracellular matrix remodelling. EMT and Wnt signaling ranked top position/s in KEGG pathway enrichment. Among sixty-four common DEGs, four genes, namely, SERPINA1, MMP11, THBS1, MMP7 have maximal node degree (>2) and MCODE (k = 2) in PPI network and were prioritized as hub genes. STRING analysis computed the network of common hub genes between adenomyosis and endometriosis. qRT-PCR findings confirmed down-regulation (p < 0.02) of SERPINA1, and MMP11 in adenomyosis compared to endometriosis and MMP7, and THBS1 in both endometriosis and adenomyosis (p < 0.03) compared to control. Down-regulation (p < 0.003) of SNORD116, MYH11 and PIGR was simultaneously observed in adenomyosis only as compared to endometriosis. Similar gene expression/s as to adenomyosis was documented in combined cohort because of possible presence of common pathology. Interestingly, posterior-wall thickness (PWT) on TVUS was positively correlated with MMP11 (r = 0.88; p<0.03) and SERPINA1 (r = 0.94; p<0.01) in adenomyosis. MMP-11 also exhibited positive correlation with PWT (r = 0.85; p<0.03) and uterine-size (r = 0.88; p<0.03) in endometriosis and combined cohort respectively while MYH11 negatively correlated (r=-0.97; p<0.02) with uterine-size in adenomyosis associated endometriosis.

Limitations, reasons for caution

The heterogeneous nature of data for bioinformatic analysis is a major limitation. Moreover, only mild adenomyosis was considered in the study; hence, results could differ in women with co-occurrence of other gynecological condition/s and/or in severe cases of adenomyosis. The observed differences need to be replicated in larger study cohort/s.

Wider implications of the findings

We identify a set of novel hub genes and enrichment pathways in receptive phase which provide an in-depth discriminative understanding between pathogenesis of endometriosis and adenomyosis. Our results suggest a dys-regulated micro-environment run an algorithmic cascade for perturbed uterine preparation (in adenomyosis), thus providing platform for newer therapeutic targets.

Trial registration number

Not Applicable

P-390 Serum homocysteine and uterine artery Doppler ultrasound in combination has better predictive accuracy in women with preeclampsia: useful tool for early screening in everyday practice

Study question

Is serum homocysteine combined with uterine-artery Doppler were effective in predicting preeclampsia (≥140mmHg/≥90mmHg blood pressure) in singleton pregnancy during 11–15 weeks of gestation?

Summary answer

Combination of serum homocysteine levels with uterine-artery Doppler is superior to individual presence of biochemical/ultrasound marker/s making the duo effective for early screening in preeclampsia.

What is known already

American College of Obstetricians and Gynecologists and National Institute for Care and Health Excellence recommend identifying patients who are at high risk of developing preeclampsia based on medical history. Recently, biochemical and ultrasound markers were investigated for prediction of preeclampsia, but none of them were predictably reliable, valid, and suitable for routine clinical use. Increased levels of homocysteine in 1st-trimester, seems to signal onset of preeclampsia later in pregnancy portraying severity of the disease as well. We aimed to identify predictive value of serum homocysteine combined with uterine-artery Doppler in singleton pregnancy during 11–15 weeks of gestation for preeclampsia.

Study design, size, duration

One hundred forty-two consented singleton pregnant women (28-45 years) at gestational age of 11–15 weeks, recruited between January to December 2021 from Institute of Reproductive Medicine, Kolkata were enrolled in the study. Women who used aspirin as a prophylaxis for preeclampsia or were diagnosed to have fetal, structural or chromosomal abnormalities were excluded from the study (n = 7). Maternal age, weight and height, mean arterial pressure, parity, and obstetric history were documented.

Participants/materials, setting, methods

Uterine-artery Doppler ultrasound and serum homocysteine levels were performed transabdominally and using ELISA respectively. Pregnancy outcomes were recorded. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) at optimal cut-off values were determined to predict preeclampsia. Optimal cut-off values for homocysteine levels were calculated using receiver operator characteristic curve (ROC). Chi-square test, Fisher’s exact test, unpaired t test, and Mann–Whitney U test were used when appropriate. P-value <0.05 was considered statistically significant.

Main results and the role of chance

16 cases had preeclampsia (11.26%) of whom 9 had early-onset preeclampsia (6.33%). Baseline characteristics including maternal-age (>35 or<), parity, body-mass- index, and gestational-age at measurement were not significantly different between two groups excepting higher (p < 0.001) mean arterial blood pressure (mmHg) at first trimester (97.2±6.4 vs. 81.1±7.2) in preeclampsia. Preeclamptic women had significantly higher (p < 0.001) serum homocysteine levels (μmol/l) (26.1±3.5 vs 10.2± 5.6) than normotensive pregnant women (n = 119). No difference in mean pulsatility (PI) of uterine-artery was observed (1.78±0.64 vs. 1.72±0.48) excluding significantly high (p > 0.02) in women with early-onset preeclampsia than control (2.11±0.81 vs. 1.39±0.92). However, lower (p < 0.01) gestational age (weeks) (35.4±2.1 vs. 37.6±1.4), and neonatal birth weight (gms) (2937.3±578.2 vs. 3227.6±421.5) with higher (p < 0.001) preterm delivery (25% vs 5.04%), low birth weight (25% vs 5.04%) and neonatal respiratory distress syndrome (12.5% vs. 0.84%) was documented in preeclampsia than control/s. The optimal cut-off value of serum homocysteine with PI levels, from ROC (AUC=0.735, p < 0.001) was superior to individual ROC (AUC=0.451; AUC=0.268). The sensitivity, specificity, PPV, and NPV were 67.7%, 70.5%, 1.7%, and 98.5%, respectively using a combination of abnormal serum homocysteine levels with abnormal uterine artery Doppler PI (above 95th percentile) and used as a predictive value for preeclampsia.

Limitations, reasons for caution

The limitation of this study was that there were small cases of early-onset preeclampsia. Additional studies with a larger sample size of early-onset preeclampsia and other models using serum homocysteine, combined with uterine artery Doppler, and maternal characteristic risk factors should be conducted.

Wider implications of the findings

Early screening of preeclampsia by using combination of serum homocysteine and uterine artery Doppler during first trimester (11–15 weeks) at the same visit may be more effective and allows the timing for using early low-dose aspirin prophylaxis in order to prevent preeclampsia.

Trial registration number

Not applicable

P-724 Gene expression profiling of cumulus cells from women with adenomyosis disclose differential pattern to endometriosis: striking the chord for evaluation of a biomarker

Study question

Can metabolic picture of cumulus cell (CC) assess assisted reproductive technology outcome/s in women with adenomyosis/endometriosis and have implications on treatment decisions?

Summary answer

The differentially expressed genes between uterine pathologies explain the functional gap to identify diagnostic/prognostic markers of CC and further dissect molecular contribution to oocyte maturation.

What is known already

A healthy intra-follicular environment supports achievement of oocyte developmental competence (ODC) largely via coordinated CC-follicular fluid (FF) crosstalk. Lately, promising studies document CC of endometriosis are involved in important pathways for ODC like oxidative phosphorylation, metabolism, mitochondrial function and acetylation to name a few. Similar presentation/s of adenomyosis to other gynecological diseases including endometriosis makes the diagnosis difficult. Given that the functional integrities of CCs are susceptible to concurrent pathological conditions, understanding the influence of CCs on oocyte quality compared to routine morphological analysis in presence of deleterious systemic or pelvic conditions may impact clinical decisions.

Study design, size, duration

Twenty-eight consented patients undergoing IVF-ICSI between January to December 2021at Institute of Reproductive Medicine, Kolkata were enrolled. CCs obtained and corresponding oocyte maturation was assessed. They were sub-stratified (n = 9) according to uterine pathologies: adenomyosis (Group A), and endometriosis (Group B) as diagnosed by transvaginal ultrasound (TVUS). Counterpart/s of male sub-fertility, defined by World Health Organization criteria (5th edition) was treated as control (Group C; n = 10). CC from mature MII and immature GV oocytes were compared.

Participants/materials, setting, methods

CCs collected following oocyte-denudation were evaluated by Trypan Blue viability test. Patient age and embryo development were recorded with respect to each cumulus complex. Real Time-quantitative polymerase-chain-reaction (qRTPCR) was performed for glycolysis (PFKP, PKM2, ALDOA, LDHA, TPI1), cholesterol-biosynthesis (CYP51, MVK, PMVK, EBP) and extracellular-matrix (PTGS2, PTX3, TNFAIP6, VCAN) related gene/s known to have important functions in cumulus expansion and metabolism. Patient characteristics and gene expression were correlated by Spearman’s correlation. P < 0.05 was considered statistically significant.

Main results and the role of chance

A significant higher (p < 0.001) age (A vs B: 35.77±2.33 vs 25.88± 1.76; A vs C: 35.77±2.33 vs 31.9±1.98) and increased number of oocytes retrieved (A vs B: 11.22±1.56 vs 8.55±0.88) was documented in adenomyosis cohort. Immature oocytes from Group A expressed enhanced cholesterol/steroid biosynthesis, with significant (A vs B; p < 0.01) up-regulation of CYP51, MVK, PMVK, EBP in spite of hyper-estrogenic environment in peripheral blood. On contrary, significant attenuation (p < 0.01) of cholesterol biosynthesis was documented in endometriosis cohort compared to control. Expression of PTGS2, PTX3 and VCAN was down-regulated (p < 0.001) (which together mediate cumulus expansion and oocyte maturation, as well as corpus luteum formation and maintenance and reduce spindle abnormalities) in both Group A and B. Expression/s of CC-PFKP and PKM2 was lower in immature compared to mature oocytes (B vs C; p < 0.01) in endometriosis making the duo responsible for follicular/oocyte growth, and embryonic development. This supports the role in promoting cumulus expansion and oocyte competence. Expression levels of other genes including ALDOA, LDHA, TPI1, and TNFAIP6 were not associated with oocyte maturity, and fertilization in either cohort/s. Interestingly, levels of VCAN, TNFAIP6, PTX3 changed significantly as a function of the subject’s age and embryo development.

Limitations, reasons for caution

Our findings are limited by the relatively small sample size and inherent biological variability of human samples. Several yet known or unknown factors are presumably involved in the implantation process of adenomyosis and/or endometriosis. Multi-centric systematic studies are needed to corroborate these findings and account for the probable confounding factors.

Wider implications of the findings

A differential metabolic dependence of CC play essential role in oocyte competence in adenomyosis influencing cumulus expansion and oocyte maturation. This would be useful to do further studies to know how molecular interface of implantation capacity with live-birth rate would be affected to complement embryonic morphological assessment/s.

Trial registration number

Not Applicable

Military and Civilian Sector Practice Patterns for Short-Term Travelers' Diarrhea Self-Treatment in Adults

The Deployment and Travel Medicine Knowledge, Attitude, Practice and Outcomes Study investigates the various clinician and traveler contributions to medical outcomes within the U.S. Military Health System. Travelers' diarrhea is among the most common travel-related illnesses, making travelers' diarrhea self-treatment (TDST) important for traveler health. A cohort of 80,214 adult travelers receiving malaria chemoprophylaxis for less than 6 weeks of travel were identified within the U.S. Department of Defense Military Health System Data Repository. Associated prescriptions for TDST medications within 2 weeks of chemoprophylaxis prescriptions were identified. Prescription patterns were compared by service member versus beneficiary status and site of care, military facility versus civilian facility. At military facilities, medical provider demographics were analyzed by clinical specialty and categorized as travel medicine specialists versus nonspecialists. Overall, there was low prescribing of TDST, particularly among civilian providers and military nonspecialists, despite guidelines recommending self-treatment of moderate to severe travelers' diarrhea. This practice gap was largest among service member travelers, but also existed for beneficiaries. Compared with nonspecialists, military travel medicine specialists were more likely to prescribe a combination of an antibiotic and antimotility agent to beneficiaries, more likely to provide any form of TDST to service members, and more likely to prescribe azithromycin than quinolones when using antibiotics. Our study suggests that enhancing provider knowledge and use of travelers' diarrhea treatment recommendations combined with improved access to formal travel medicine services may be important to increase the quality of care.

TaqMan Array Card testing of participant-collected stool smears to determine the pathogen-specific epidemiology of travellers' diarrhoea†

BACKGROUND

We assessed the compliance with self-collection of stool smears on Whatman® FTA® Elute Card (FTA Card) and detection of travellers' diarrhoea (TD)-associated pathogens by using a quantitative Polymerase Chain Reaction (PCR) assay [customized TaqMan® array card (TAC)] in a prospective, observational cohort of travellers.

METHODS

Enrolled travellers documented symptoms on a travel diary and collected an FTA Card during a diarrhoeal episode, or at the end of travel if they remained asymptomatic. TAC testing was performed on FTA Cards from TD cases and 1:1 matched asymptomatic controls and 1:1 matched loose stool cases that did not meet TD criteria. Odds ratios were used to determine the association between detected pathogens and TD.

RESULTS

Of 2456 travellers, 484 (19.7%) completed an illness diary and met TD criteria, and 257 (53.1%) collected an FTA Card during the TD episode. FTA Cards were stored for a median of 2 years at room temperature (IQR: 1-4 years) before extraction and testing. The overall TAC detection rate in TD cases was 58.8% (95% CI: 52.5-64.8). Enterotoxigenic Escherichia coli was the most common pathogen in TD cases (26.8%), and 3.5% of samples were positive for norovirus. The odds of detecting TD-associated pathogens in 231 matched cases and asymptomatic controls were 5.4 (95% CI: 3.6-8.1) and 2.0 (95% CI: 1.1-3.7) in 121 matched TD and loose stool cases (P < 0.05). Enteroaggregative E. coli was the most common pathogen detected in asymptomatic controls and loose stool cases. Detection of diarrhoeagenic E. coli, Shigella/enteroinvasive E. coli and Campylobacter spp. was significantly associated with TD.

CONCLUSION

FTA Cards are a useful adjunct to traditional stool collection methods for evaluating the pathogen-specific epidemiology of TD in austere environments. Qualitative detection of pathogens was associated with TD. Measures to improve compliance and quality of FTA Card collection with decreased storage duration may further optimize detection.

Helminth infections in the US military: from strongyloidiasis to schistosomiasis

BACKGROUND

Helminth infections caused by parasitic worms, including nematodes (roundworms), cestodes (tapeworms) and trematodes (flukes), can cause chronic symptoms and serious clinical outcomes if left untreated. The US military frequently conducts activities in helminth-endemic regions, particularly Africa, the Middle East and Southeast Asia. However, the military does not currently screen for these infections, and to date, no comprehensive surveillance studies have been completed to assess the frequency of helminth diagnoses in the military personnel and their families.

METHODS

To determine the burden of helminth infections in the US Military Health System (MHS), we conducted a retrospective analysis of International Classification of Diseases (ICD)-9/10 diagnosis codes from all medical encounters in the MHS Data Repository (MDR) from fiscal years (FY) 2012 to 2018. Chart reviews were conducted to assign ICD diagnoses as incorrect, suspected, probable or confirmed based on the laboratory results and symptoms.

RESULTS

Abstraction of MHS data revealed over 50 000 helminth diagnoses between FY 2012 and FY 2018. Of these, 38 445 of diagnoses were amongst unique subjects. After chart review, we found there were 34 425 validated helminth infections diagnosed amongst the unique subjects of US military personnel, retirees and dependents. Nearly 4000 of these cases represented infections other than enterobiasis. There were 351 validated strongyloidiasis diagnoses, 317 schistosomiasis diagnoses and 191 diagnoses of cysticercosis during the study period. Incidence of intestinal nematode infection diagnoses showed an upward trend, whilst the incidence of cestode infection diagnoses decreased.

CONCLUSIONS

The results of this study demonstrate that helminth infections capable of causing severe morbidity are often diagnosed in the US military. As helminth infections are often asymptomatic or go undiagnosed, the true burden of helminth infections in US military personnel and dependents may be higher than observed here. Prospective studies of US military personnel deployed to helminth-endemic areas may be indicated to determine if post-deployment screening and/or empirical treatment are warranted.

Travel-associated multidrug-resistant organism acquisition and risk factors among US military personnel

BACKGROUND

International travel is a risk factor for incident colonization with extended spectrum beta-lactamase (ESBL)-producing organisms. These and other multidrug-resistant (MDR) bacteria are major pathogens in combat casualties. We evaluated risk factors for colonization with MDR bacteria in US military personnel travelling internationally for official duty.

METHODS

TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. We analysed surveys, antimicrobial use data, and pre- and post-travel perirectal swabs in military travellers to regions outside the continental USA, Canada, Western or Northern Europe, or New Zealand, presenting to one clinic from 12/2015 to 12/2017. Recovered Gram-negative isolates underwent identification and susceptibility testing (BD Phoenix). Characteristics of trip and traveller were analysed to determine risk factors for MDR organism colonization.

RESULTS

110 trips were planned by 99 travellers (74% male, median age 38 years [IQR 31, 47.25]); 72 trips with returned pre- and post-travel swabs were completed by 64 travellers. Median duration was 21 days (IQR 12.75, 79.5). 17% travelled to Mexico/Caribbean/Central America, 15% to Asia, 57% to Africa and 10% to South America; 56% stayed in hotels and 50% in dormitories/barracks. Travellers used doxycycline (15%) for malaria prophylaxis, 11% took an antibiotic for travellers' diarrhoea (TD) treatment (fluoroquinolone 7%, azithromycin 4%). Incident MDR organism colonization occurred in 8 travellers (incidence density 3.5/1000 travel days; cumulative incidence 11% of trips [95% CI: 4-19%]), all ESBL-producing Escherichia coli. A higher incidence of ESBL-producing E. coli acquisition was associated with travel to Asia (36% vs 7%, P = 0.02) but not with travel to other regions, TD or use of antimicrobials. No relationship was seen between fluoroquinolone or doxycycline exposure and resistance to those antimicrobials.

CONCLUSIONS

Incident colonization with MDR organisms occurs at a lower rate in this military population compared with civilian travellers, with no identified modifiable risk factors, with highest incidence of ESBL acquisition observed after South Asia travel.

632. A Randomized, Placebo-Controlled, Double-Blind, Clinical Trial Evaluating Two Dose Regimens of Rifaximin (550mg daily or twice-daily) for Chemoprophylaxis Against Travelers’ Diarrhea Among Deployed U.S. and U.K. Military Personnel (PREVENT TD)

Background

Travelers’ diarrhea (TD) is a leading threat to military readiness. Most trials of rifaximin chemoprophylaxis involve civilians or short-duration travel, whereas military travelers are exposed for longer periods at austere locations and are often physically taxed. We sought to assess efficacy of two regimens among military personnel deployed overseas.

Methods

This was a multi-site, double-blind, placebo-controlled trial of deployed military, randomized to placebo, rifaximin 550 mg daily, or rifaximin 550 mg twice-daily, for up to 42 days (1:1:1; 6 randomizations/block). Diaries were reviewed with subjects on return. Primary endpoint was time to first unformed stool (TFUS) in a TD episode. Other endpoints were assessed by intention to treat (ITT) and subgroups included incidence of any loose stool, meeting criteria for TD, safety, efficacy, adherence and impact to activity endpoints.

Results

343 subjects were included in the ITT population. All UK travelers deployed to a single-site in Kenya; US travelers mostly deployed to various Asia-Pacific locations. Of 73 (21.2%) subjects reporting diarrhea, 42 (57.5%) met TD criteria. Among rifaximin-treated subjects, 15.9% (n=17) reported diarrhea in the twice-daily arm, 20.7% (n=25) in the daily arm, vs. 27.0% (n=31) of placebo recipients; p=.04 and 0.26 respectively. TD was reported by 10.3% (n=11) and 10.7% (n=13) in the daily and twice-daily arms, vs. 15.7% (n=18) among placebo recipients; p=0.24 vs. 0.26 respectively. Among UK personnel, a twice-daily regimen vs. placebo resulted in significantly fewer TD episodes (1.6% vs. 11.9%; p=0.03). Adverse events were similar between groups.

Table 1: Demographics, endpoints, and adverse events (Comparisons are across placebo vs. each dosing regimen. Intent-to-treat [ITT] population defined as subjects enrolled into the study, randomized, travelled and had follow-up. p-values calculated from chi-square or Fisher’s exact test [categorical variables] and Wilcoxon-Mann-Whitney test [continuous variables]. Analyses performed on SAS v9.4. BID: twice-daily)

Conclusion

This is the first trial comparing two high-dose regimens of rifaximin prophylaxis in deployed personnel. Unlike prior reports, neither regimen was associated with an overall significant decrease in TD, potentially due to low overall TD incidence. However, the twice-daily regimen was associated with a numerically lower incidence of diarrheal stool, and in the UK subject group, there was a significant decrease of both TD and diarrheal stool. The impact of variability in regional TD risk, pathogen distribution and adherence in austere deployment environments on efficacy will be reviewed.

Disclosures

All Authors: No reported disclosures

Doxycycline Malaria Prophylaxis Impact on Risk of Travelers' Diarrhea among International Travelers

International travelers are frequently at risk for travelers' diarrhea (TD) and malaria. Doxycycline was one of the earliest antibiotics shown to have efficacy in TD prevention. With increasing resistance and recommendations against antibiotic chemoprophylaxis, doxycycline fell out of use. We evaluated TD incidence and risk factors in a prospective cohort of travelers, specifically in regard to malaria prophylaxis. Travelers' diarrhea was defined as ≥ 3 loose stools in 24 hours or two loose stools in 24 hours associated with other gastrointestinal symptoms. The Poisson regression model with robust error variance was used to estimate the RR of TD. Three thousand two hundred twenty-seven trips were enrolled: 62.1% of participants were male, with a median age of 39 years (interquartile range [IQR] 27,59) and a median travel duration of 19 days (IQR 12,49); 17.4% developed TD; 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean and Latin America; and 20% took doxycycline for malaria chemoprophylaxis, 50% took other antimalarials, and 30% took none. Decreased RR of TD was associated with doxycycline (RR 0.62 [0.47-0.82], P < 0.01) and military travel (RR 0.57 [0.47-0.70], P < 0.01). Increased risk of TD was associated with female gender (RR 1.28 [1.09-1.50], P < 0.01), hotel accommodations (RR 1.30 [1.10-1.53], P < 0.01), travel to tropical South America (RR 1.34 [1.09-1.64], P < 0.01), and duration of travel (RR 1.00 [1.00-1.01], P < 0.01). The use of doxycycline for malaria prophylaxis is associated with lower TD risk, suggesting increasing bacterial enteropathogen susceptibility similar to previous observations. Doxycycline selection for antimalarial chemoprophylaxis may provide additional traveler benefit in infection prevention.

Performance characteristics of a quantitative PCR assay on repository stool specimens and smeared filter-paper cards

Objective

Stool repositories are a valuable resource for retrospective analyses including quantitative PCR assays to distinguish between asymptomatic shedding and clinical disease. The suitability of archival specimens for this purpose is unclear and requires assessment. We conducted a pilot study to evaluate pathogen detection by TaqMan Array Card (TAC) in travelers’ diarrhea (TD) stool specimens stored for 1–13 years, as well as the impact of transporting specimens on Whatman FTA Elute cards (FTA Cards) on detection.

Results

The positive percent agreement (PPA) for TAC on stool vs. microbiologic testing was lower than our a priori PPA estimate of 80% for most pathogens: Shigella spp. (100% [95%CI 69–100%]), enterotoxigenic E coli (ETEC) (63% [95%CI 49–75%]), Campylobacter spp. (66% [95%CI 43–85%]) and Norovirus (37% [95%CI 16–61%]). Use of the FTA card resulted in a further reduction of PPA. Our findings suggest that archival specimens may lead to insensitive detection on quantitative PCR assays due to degradation of nucleic acid with prolonged storage, although our limited sample size precluded us from evaluating the impact of storage duration on nucleic acid yield. Additional studies are needed to understand the impact of storage duration on quantitative PCR data.

Impact of Doxycycline as Malaria Prophylaxis on Risk of Influenza-Like Illness among International Travelers

Travelers are often at risk for both influenza-like illness (ILI) and malaria. Doxycycline is active against pathogens causing ILI and is used for malaria prophylaxis. We evaluated the risk factors for ILI, and whether the choice of malaria prophylaxis was associated with ILI. TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. Influenza-like illness was defined as subjective fever with either a sore throat or cough. Characteristics of trip and use of malaria prophylaxis were analyzed to determine association with development of ILI. Poisson regression models with robust error variance were used to estimate relative risk (RR) of ILI. A total of 3,227 trips were enrolled: 62.1% male, median age of 39 years (interquartile range [IQR] 27,59), median travel duration 19 days (IQR 12, 49); 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean and Latin America. Military travel (46%) and vacation (40%) were most common reasons for travel. Among them, 20% took doxycycline, 50% other prophylaxis, and 30% took none; 8.7% developed ILI. Decreased RR of ILI was associated with doxycycline (RR 0.65 [0.43–0.99], P = 0.046) and military travel (RR 0.30 [0.21–0.43], P < 0.01). Increased risk of ILI was associated with female gender (RR 1.57 [1.24–1.98], P < 0.01), travel to Asia (RR 1.37 [1.08–1.75], P = 0.01), and cruises (RR 2.21 [1.73–2.83], P < 0.01). Use of doxycycline malaria prophylaxis is associated with a decreased risk of ILI. Possible reasons include anti-inflammatory or antimicrobial effects, or other unmeasured factors. With few strategies for decreasing ILI in travelers, these findings bear further investigation.

Deployment and Travel Medicine Knowledge, Attitudes, Practices, and Outcomes Study (KAPOS): Malaria Chemoprophylaxis Prescription Patterns in the Military Health System

The Deployment and Travel Medicine Knowledge, Attitudes, Practices, and Outcomes Study (KAPOS) examines the integrated relationship between provider and patient inputs and health outcomes associated with travel and deployments. This study describes malaria chemoprophylaxis prescribing patterns by medical providers within the U.S. Department of Defense’s Military Health System and its network of civilian healthcare providers during a 5-year period. Chemoprophylaxis varied by practice setting, beneficiary status, and providers’ travel medicine expertise. Whereas both civilian and military facilities prescribe an increasing proportion of atovaquone–proguanil, doxycycline remains the most prevalent antimalarial at military facility based practices. Civilian providers dispense higher rates of mefloquine than their military counterparts. Within military treatment facilities, travel medicine specialists vary their prescribing pattern based on service member versus beneficiary status of the patient, both in regards to primary prophylaxis, and use of presumptive anti-relapse therapy (PQ-PART). By contrast, nonspecialists appear to carry over practice patterns developed under force health protection (FHP) policy for service members, into the care of beneficiaries, particularly in high rates of prescribing doxycycline and PQ-PART compared with both military travel medicine specialists and civilian comparators. Force health protection policy plays an important role in standardizing and improving the quality of care for deployed service members, but this may not be the perfect solution outside of the deployment context. Solutions that broaden both utilization of decision support tools and travel medicine specialty care are necessary.

741. TravMil Surveillance of Travel-Related Illness in a Prospective Cohort of US Military Beneficiaries, 2010–2018

Background

Increasing international travel places larger populations at risk for infections outside of their usual exposure. Deployed military personnel have unique risks for such infections. Our cohort’s rates of travelers’ diarrhea and influenza-like illness have been defined, but the rate of travelers with symptoms apart from a clinical syndrome has not. We present a survey of intra-travel symptoms of all travelers and confirmed diagnoses of ill-returned travelers in a cohort of military and civilian travelers.

Methods

TravMil is a prospective, multicenter observational study enrolling US military beneficiaries traveling outside the continental United States from 2010–2018; beneficiaries could also enroll after travel if they presented for a possible travel-related illness. Demographic information, intra-travel symptoms, and confirmed diagnoses were recorded.

Results

2671 travelers embarked on 3050 trips: 63.1% male; median age 38 years (IQR 27, 57); median trip duration 20 days (IQR 13, 46). Common purposes of travel: military deployment (45.9%), vacation (23.7%), and visiting friends/relatives (10.9%). Ninety-seven travelers (3.2%) enrolled post-travel. Top regions of travel: Africa (31.5%), South and Central America/Caribbean (25.5%), and Southeast and North Asia/Oceania (19.4%). During travel, 56.6% experienced gastrointestinal (GI) symptoms, 11.9% respiratory symptoms, and 3.0% fever; of those, 10.3% sought medical care. Eighty returned travelers sought medical care (21 prospective enrollees vs. 59 post-travel enrollees): 5 vs. 17 malaria cases, 3 vs. 16 arbovirus infections, and 6 vs. 14 GI syndromes. All malaria cases in prospective enrollees were in military subjects. Post-travel enrollees accounted for 1 acute human immunodeficiency virus and 3 rickettsial infections.

Conclusion

A majority of our travelers experienced symptoms during travel. Post-travel diagnoses, although uncommon, emphasize needed improvements in the application of known risk mitigation strategies. Our findings can help clinicians optimize their pretravel counseling by focusing education on self-treatment of common travel-related symptoms, prevention of GI, arthropod-borne, and respiratory illness, and emphasizing symptoms that should prompt medical care.

Disclosures

All authors: No reported disclosures.

Influenza-Like Illness in Travelers to the Developing World

Travelers to developing regions are at risk for development of influenza-like illness (ILI). Little is known of traveler and trip characteristics associated with the development of ILI. TravMil is a prospective observational study, enrolling subjects presenting to six military travel clinics or predeployment-screening sites. We analyzed pre- and post-travel surveys from travelers visiting regions outside of the continental United States, Western or Northern Europe, Canada, Australia, or New Zealand between January 2010 and March 2016. Influenza-like illness was defined as a self-reported fever associated with either sore throat or cough. Trip and traveler characteristics were analyzed to determine risk factors for the development of ILI. Two thousand nine hundred and thirty-two trips were recorded (55% male, median age 45 years, 69% white, 51% on vacation, median travel duration 17 days). The 2,337 trips included the number of self-reported influenza vaccinations in the preceding 5 years (median 5). Eleven percent of the trips were complicated by an ILI lasting a median of 5 days; 70% and 17% of these reported upper and lower respiratory tract infection, respectively, and 12% reported both. On multivariate analysis, increased risk of ILI was associated with female gender (odds ratio [OR]: 1.60 [confidence interval (CI): 1.25-2.05], P < 0.01), age (years) (OR: 1.01 [CI: 1.01-1.02], P < 0.01); and duration of travel (days) (OR: 1.01 [CI: 1.00-1.01], P < 0.01). Influenza-like illness is common in travelers, regardless of traveler characteristics, purpose of travel, destination, or season of year. Female gender, older age, and longer duration of travel were associated with an increased risk of ILI. Additional tools and strategies are needed to prevent ILI in international travelers.

A Comparison of Pretravel Health Care, Travel-Related Exposures, and Illnesses among Pediatric and Adult U.S. Military Beneficiaries

We evaluated differences in pretravel care, exposures, and illnesses among pediatric and adult travelers, using a prospective, observational cohort. Eighty-one pediatric travelers were matched 1:1 with adult military dependents by travel region, destination's malaria risk, and travel duration. Pediatric travelers were more likely to have coverage for hepatitis A and B (90% versus 67% of adults; 85% versus 44%), visit friends and relatives (36% versus 16%), report mosquito bites (69% versus 44%), and have close contact with wild or domesticated animals (40% versus 20%) than adults (P < 0.05). Subjects < 10 years of age were less likely to be prescribed antibiotics (28% versus 95%; RR = 0.63; 95% CI: 0.46-0.85) and antidiarrheals (9% versus 100%; RR = 0.10; 95% CI: 0.03-0.29) for travelers' diarrhea (TD) self-treatment than adults. Travel medicine providers should emphasize strategies for vector avoidance, prevention of animal bites and scratches, and TD self-treatment in pediatric pretravel consultations.

964. Impact of Doxycycline as Malaria Prophylaxis on Risk of Influenza Like Illness Among International Travelers

Background

International travelers are often at risk for both influenza like illness (ILI) and malaria. Doxycycline is active against many pathogens causing ILI and is routinely used for malaria prophylaxis. We evaluated the incidence of and risk factors for ILI, and whether the choice of malaria prophylaxis was associated with ILI.

Methods

TravMil is a prospective observational study enrolling subjects presenting to 6 military travel clinics. We analyzed pre- and post-travel surveys from travelers to regions outside of the continental United States, Western or Northern Europe, Canada, or New Zealand between July 2010 and August 2018. ILI was defined as subjective fever associated with either a sore throat or cough. Characteristics of trip and traveler and the use of malaria prophylaxis were analyzed to determine association with development of ILI. Poisson regression models with robust error variance were used to estimate relative risk of ILI.

Results

A total of 3,227 travelers were enrolled: 62.1% male, median age of 39 (IQR 27, 59), median travel duration 19 days (IQR 12, 49). 32% traveled to Africa, 40% to Asia, and 27% to the Caribbean, Mexico, and Central or South America. Military travel (46%) and vacation (40%) were most common reasons for travel. Twenty percent took doxycycline for malaria prophylaxis, 50% other prophylaxis (89% atovaquone–proguanil), and 30% took none. 8.7% developed ILI. Compared with those on no or other prophylaxis, doxycycline was associated with decreased risk of ILI [RR 0.65 (0.43–0.99), P = 0.046], as was military travel [RR 0.30 (0.21–0.43), P &lt; 0.01]. Increased risk of ILI was associated with female gender [RR 1.57 (1.24–1.98), P &lt; 0.01], travel to Asia [RR 1.37 (1.08–1.75), P = 0.01], cruises [RR 2.21 (1.73–2.83), P &lt; 0.01], and longer duration of travel [RR 1.01 (1.00–1.01, P &lt; 0.01].

Conclusion

The use of doxycycline is associated with a decreased risk of ILI compared with taking no or other malaria prophylaxis. The reasons for this are unclear but may be related to anti-inflammatory effects, activity against bacterial respiratory pathogens, effects on disease transmission in closed populations (e.g., military deploying groups), or other unmeasured factors. With few proven strategies for decreasing ILI risk in travelers, these findings bear further investigation.

Disclosures

All authors: No reported disclosures.

1172. Travel-Associated Multidrug-Resistant Organism Acquisition and Risk Factors Among US Military Personnel

Background

International travel is a risk factor for incident colonization with extended spectrum β-lactamase (ESBL)-producing organisms. These and other multidrug-resistant (MDR) bacteria are major pathogens in combat casualties. We evaluated risk factors for colonization with MDR bacteria in US military personnel traveling internationally for official duty.

Methods

TravMil is a prospective observational study enrolling subjects presenting to military travel clinics. We analyzed surveys, antimicrobial use data, and pre- and post-travel self-collected perirectal swabs in military travelers to regions outside the continental United States, Canada, Western or Northern Europe, or New Zealand presenting to one clinic from December 2015 to December 2017. Gram-negative isolates recovered from swabs underwent real-time identification and susceptibility testing (BD Phoenix). Characteristics of trip and traveler were analyzed to determine risk factors for MDR organism colonization.

Results

One hundred ten trips were planned by 99 travelers (74% male, median age 38 years [IQR 31, 47.25]); 72 trips were completed by 64 travelers. Median trip duration was 21 days (IQR 12.75, 79.5). Of those with trips completed, 17% traveled to Mexico/Caribbean/Central America, 15% to Asia, 57% to Africa, and 10% to South America; 56% stayed in hotels and 50% in dormitories/barracks. Travelers used doxycycline (15%) for malaria prophylaxis, 11% took an antibiotic for travelers’ diarrhea (TD) treatment (fluoroquinolone 7%, azithromycin 4%). Incident MDR organism colonization occurred in eight travelers (incidence density 3.5/1,000 travel days; cumulative incidence 11% of trips [95% CI: 4%–19%]), all ESBL-producing E. coli. A higher incidence of ESBL-producing E. coli acquisition was associated with travel to Asia (36% vs. 7%, P = 0.02) but not with travel to other regions, TD, or use of antimicrobials. No relationship was seen between fluoroquinolone or doxycycline exposure and resistance to those antimicrobials.

Conclusion

Consistent with other studies of US military personnel travelers, incident colonization with MDR organisms following official travel occurs at a lower rate in this population compared with civilian travelers, with no identified modifiable risk factors. The highest incidence of ESBL acquisition was observed during travel to Asia.

Disclosures

All authors: No reported disclosures.

Comparison of stool collection and storage on Whatman FTA Elute cards versus frozen stool for enteropathogen detection using the TaqMan Array Card PCR assay

The use of Polymerase Chain Reaction (PCR) assays for pathogen detection in travelers' diarrhea (TD) field studies is limited by the on-site processing and storage requirements for fecal specimens. The objectives of this investigation were to i) characterize the pathogen distribution in deployed military personnel with TD using the TaqMan® Array Card PCR (TAC) on frozen stool and diarrheal smears on Whatman FTA Elute cards (FTA cards), and to ii) compare TAC detection of enteropathogen targets using smeared FTA cards and frozen stool, using TAC on frozen stool as the 'reference standard'. Stool samples, obtained from active duty personnel with acute TD enrolled in a field trial, were smeared onto FTA cards and stored at room temperature. A corresponding aliquot of stool was frozen in a cryovial. FTA cards and frozen stool samples were tested at a central lab, using a customized TAC for detection of TD pathogens. 187 paired frozen stool samples and smeared FTA cards were stored for a median of 712 days (IQR 396-750) before testing. Overall detection rates were 78.6% for frozen stool and 73.2% for FTA cards. Diarrheagenic Escherichia coli were the most common bacteria identified. Using the TAC results on frozen stool as the reference, the overall sensitivity and specificity of TAC on FTA cards was 72.9% and 98.0% respectively. TAC on FTA cards demonstrated a decrease in sensitivity with increasing frozen stool quantification cycle (Cq) (90.0% in FTA cards with a corresponding frozen stool Cq < 30, and 72.9% in samples with a corresponding frozen stool Cq < 35). Our findings support the use and further development of FTA cards in combination with a quantitative PCR assay for enteropathogen detection in TD field studies.

Aggressive fibromatosis response to tamoxifen: lack of correlation between MRI and symptomatic response

Background

One of the commonly used systemic agents for the treatment of aggressive fibromatosis is the anti-oestrogen drug tamoxifen. However, data on efficacy and optimum methods of response assessment are limited, consisting mainly of small case series and reports.

Methods

A retrospective database was used to identify consecutive patients diagnosed with aggressive fibromatosis (AF) and treated with tamoxifen plus/minus non-steroidal anti-inflammatory drugs at our tertiary referral centre between 2007 and 2014. MRI and symptom changes were recorded.

Results

Thirty-two patients (13 male 19 female, median age 41 years) were included. Median duration of treatment with tamoxifen was 316 days. Of 9 patients with progressive disease by RECIST 1.1 (28%): 4 patients experienced worsening symptoms; 3 patients had improved symptoms and 2 had no change in symptoms. Of 22 patients with stable disease (69%): 11 had no change in symptoms; 6 had improved symptoms and 5 patients had worsening symptoms. One patient achieved a partial response with improved symptoms.

Conclusions

No relationship was identified between symptomatic benefit and response by RECIST 1.1 on MRI. Prospective studies in AF should incorporate endpoints focusing on patient symptoms.

Vaccination of active component US military personnel against Salmonella Typhi

INTRODUCTION

Vaccination against Salmonella Typhi is one of the leading public health interventions reducing the risk of typhoid fever. There are two available licensed vaccines, Vivotif, oral live-attenuated, and Typhim Vi, intramuscular Vi capsular polysaccharide. The US military is a high risk travel population commonly vaccinated for S. Typhi. We describe the use of S. Typhi vaccination in this population and the acute reactogenicity profile of these vaccines.

METHODS

Data were obtained from the Defense Medical Surveillance System and vaccination identified between 1998 and 2011 from vaccination codes. Clinical outcomes were assessed for four weeks post vaccination. Adverse event rates and odds ratios were estimated across the two vaccine types.

RESULTS

A total of 1.9million predominately male military personnel received 3.6 million S. Typhi vaccinations with 94.3% of vaccinees receiving the Vi capsule vaccine though variability in the vaccine administered was observed. Receipt of other vaccinations in the 6months surrounding the S. Typhi vaccine was common. Rates of nausea (195 per 100,000 vaccinations), headache (13 per 100,000 vaccinations) and fever (40 per 100,000 vaccinations) were significantly higher following Vi capsule vaccination compared to receipt of Vivotif (130, 2, 10 per 100,000 vaccinations, respectively). In contrast the rates of rash and non-infectious diarrhea (186 and 426 per 100,000 vaccinations, respectively) were increased in those receiving Vivotif compared to the Vi capsule vaccine.

DISCUSSION

The US military is a major consumer of S. Typhi vaccines. The parenterally administered vaccine appears to be more amenable, though we were limited in our ability to assess the reasons for its higher usage. While we observed a higher rate of several adverse events in subjects receiving the intramuscular vaccination, the overall rate of these events was low. Future studies assessing more long-term health outcomes are warranted.

A comparison of compliance rates with anti-vectorial protective measures during travel to regions with dengue or chikungunya activity, and regions endemic for Plasmodium falciparum malaria

BACKGROUND

There is limited information on compliance rates with anti-vectorial protective measures (AVPMs) during travel to countries with risk of dengue and chikungunya. We evaluated differences in mosquito exposures, and factors associated with AVPM compliance in travellers going to countries where the principal mosquito-borne infectious disease threat is falciparum malaria and those where risk of dengue or chikungunya predominates.

METHODS

Department of Defence beneficiaries with planned travel to regions where the predominant mosquito-borne infection is falciparum malaria, and those with predominantly dengue or chikungunya risk, were included. Regions were divided into three groups: 'high-risk falciparum malaria', 'low-risk falciparum malaria' and 'chikungunya/dengue risk'. Demographics, trip characteristics, arthropod exposure and AVPM compliance were captured using pre- and post-travel surveys. Skin repellent compliance was defined as self-reported use, categorized as 'often/every day'. A logistic regression model was used to estimate factors associated with AVPM compliance.

RESULTS

183 (9%), 185 (9%) and 149 (7%) travelled to high and low falciparum malaria risk regions, and chikungunya/dengue risk regions, respectively. Overall, 53% (95% CI: 48-57%) and 16% (95% CI: 12-19%) were compliant with repellent use on skin and clothing, respectively. Daytime bites were reported more frequently in chikungunya/dengue risk regions than high malaria risk regions (37% vs. 10%), while night time bites were frequently in high malaria risk regions (53% vs 20%; P < 0.001). Compliance with skin repellents was associated with female gender [RR: 1.54 (95% CI: 1.05-2.28)], observing mosquitoes during travel [RR: 2.77 (95% CI: 1.76-4.36)] and travel during the rainy season [RR: 2.45 (95% CI: 1.66-3.71)]).

CONCLUSIONS

Poor AVPM compliance was observed in the overall cohort. Compliance with skin repellent use was associated with female gender, observing mosquitoes and travelling during the rainy season, and was not associated with the risk of malaria or chikungunya/dengue at the travel destination.

Abstract SS1-1: Breast cancer early detection strategies in absence of screening mammography

In spite of the current controversy surrounding over-diagnosis, mammography remains the gold standard for breast cancer screening in the developed world. However, mammography is not suitable technology for low-income countries because of its high cost and the sophisticated infrastructure that is needed to realize its effectiveness. Breast self examination (BSE) may appear to be an appropriate screening procedure; however, randomized trials in the erstwhile Soviet Union and China have produced negative results largely because of non-compliance. Clinical breast examination (CBE) is also an attractive option for low-income countries. Robust evidence of effectiveness of CBE from randomized trials of head-to-head comparison of CBE with no screening is lacking. Indirect evidence from the Canadian NBSS suggests that, in women aged 50 – 59, mammography adds little to mortality reduction over and above that achieved by CBE alone. A randomized trial in Mumbai is underway comparing CBE + BSE teaching with no screening and the results are expected in 2016. Thus, at the present time, direct evidence is lacking to recommend CBE as a screening procedure in low-income countries.

The incidence of breast cancer, although rising, remains substantially lower in low-income countries than that in the developed world. For example, in India, the crude incidence rate is 18.45 per 100,000 compared to 157.1 in the US. Low incidence rates raise serious questions about cost-effectiveness of screening. Lack of adequate and easily accessible breast cancer treatment facilities and that of reliable cancer registries are other barriers to screening in these countries. Lack of awareness about hazards of breast cancer is another major challenge since this leads to low motivation and poor compliance to screening. A high degree of compliance is essential at every level of screening for it to be successful. These include compliance to the screening test, attendance at the referral center for further investigations, compliance to the prescribed treatment if cancer is confirmed, completing the entire course of treatment which can be prolonged and attendance at regular follow-up. Although the Mumbai study recorded &gt;70% compliance overall, this was achieved at a high man-power cost. Nearly 100 full-time personnel had to be engaged to make door-to-door visits on multiple occasions to persuade women to comply with the various steps of screening in addition to examining 75,000 women every two years and maintaining yearly surveillance on the control group. The study highlighted that for screening to be successful in low-awareness countries, a vertical programme is essential. A rough estimate based on the Mumbai experience suggests that a vertical programme to screen all women aged 35 – 64 in India, and to achieve ∼70% compliance, would require over US$ 100 million per year in man-power cost alone. Whether this money is better spent on strengthening breast cancer treatment facilities, for developing human resource in cancer care or for remedying the many deficiencies in the health-care delivery system in general is the moot question.

Citation Format: Mitra I. Breast cancer early detection strategies in absence of screening mammography. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr SS1-1.

Imaging of focal calvarial lesions

Focal calvarial lesions may present as a visible, palpable, or symptomatic lump; however, with increasing use of cross-sectional imaging they are often encountered as an incidental finding. Knowledge of the possible disease entities along with a structured approach to imaging is required to suggest an appropriate diagnosis and assist in management planning. Abnormalities range from common neoplastic lesions to rarer congenital conditions, benign pathologies, and calvarial defects that can mimic lesions. The aim of this article is to demonstrate the salient imaging features that may help to limit the differential diagnosis of a focal calvarial lesion.

Development of a pan-serotype reverse transcription loop-mediated isothermal amplification assay for the detection of dengue virus

During dengue outbreaks, acute diagnosis at the patient's point of need followed by appropriate supportive therapy reduces morbidity and mortality. To facilitate needed diagnosis, we developed and optimized a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay that detects all 4 serotypes of dengue virus (DENV). We used a quencher to reduce nonspecific amplification. The assay does not require expensive thermocyclers, utilizing a simple water bath to maintain the reaction at 63 °C. Results can be visualized using UV fluorescence, handheld readers, or lateral flow immunochromatographic tests. We report a sensitivity of 86.3% (95% confidence interval [CI], 72.7-94.8%) and specificity of 93.0% (95% CI, 83.0-98.1%) using a panel of clinical specimens characterized by DENV quantitative reverse transcription-polymerase chain reaction. This pan-serotype DENV RT-LAMP can be adapted to field-expedient formats where it can provide actionable diagnosis near the patient's point of need.

Evaluation of nucleic acid stabilization products for ambient temperature shipping and storage of viral RNA and antibody in a dried whole blood format

Loss of sample integrity during specimen transport can lead to false-negative diagnostic results. In an effort to improve upon the status quo, we used dengue as a model RNA virus to evaluate the stabilization of RNA and antibodies in three commercially available sample stabilization products: Whatman FTA Micro Cards (GE Healthcare Life Sciences, Pittsburgh, PA), DNAstāble Blood tubes (Biomātrica, San Diego, CA), and ViveST tubes (ViveBio, Alpharetta, GA). Both contrived and clinical dengue-positive specimens were stored on these products at ambient temperature or 37°C for up to 1 month. Antibody and viral RNA levels were measured by enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays, respectively, and compared with frozen unloaded controls. We observed reduced RNA and antibody levels between stabilized contrived samples and frozen controls at our earliest time point, and this was particularly pronounced for the FTA cards. However, despite some time and temperature dependent loss, a 94.6-97.3% agreement was observed between stabilized clinical specimens and their frozen controls for all products. Additional considerations such as cost, sample volume, matrix, and ease of use should inform any decision to incorporate sample stabilization products into a diagnostic testing workflow. We conclude that DNAstāble Blood and ViveST tubes are useful alternatives to traditional filter paper for ambient temperature shipment of clinical specimens for downstream molecular and serological testing.

Evaluation of dengue NS1 antigen rapid tests and ELISA kits using clinical samples

Background

Early diagnosis of dengue virus (DENV) infection can improve clinical outcomes by ensuring close follow-up, initiating appropriate supportive therapies and raising awareness to the potential of hemorrhage or shock. Non-structural glycoprotein-1 (NS1) has proven to be a useful biomarker for early diagnosis of dengue. A number of rapid diagnostic tests (RDTs) and enzyme-linked immunosorbent assays (ELISAs) targeting NS1 antigen (Ag) are now commercially available. Here we evaluated these tests using a well-characterized panel of clinical samples to determine their effectiveness for early diagnosis.

Methodology/Principal Findings

Retrospective samples from South America were used to evaluate the following tests: (i) “Dengue NS1 Ag STRIP” and (ii) “Platelia Dengue NS1 Ag ELISA” (Bio-Rad, France), (iii) “Dengue NS1 Detect Rapid Test (1^st Generation)” and (iv) “DENV Detect NS1 ELISA” (InBios International, United States), (v) “Panbio Dengue Early Rapid (1^st generation)” (vi) “Panbio Dengue Early ELISA (2^nd generation)” and (vii) “SD Bioline Dengue NS1 Ag Rapid Test” (Alere, United States). Overall, the sensitivity of the RDTs ranged from 71.9%–79.1% while the sensitivity of the ELISAs varied between 85.6–95.9%, using virus isolation as the reference method. Most tests had lower sensitivity for DENV-4 relative to the other three serotypes, were less sensitive in detecting secondary infections, and appeared to be most sensitive on Day 3–4 post symptom onset. The specificity of all evaluated tests ranged from 95%–100%.

Conclusions

ELISAs had greater overall sensitivity than RDTs. In conjunction with other parameters, the performance data can help determine which dengue diagnostics should be used during the first few days of illness, when the patients are most likely to present to a clinic seeking care.

Laparoscopic removal of persistent muellerian duct structures and orchiopexy

The treatment of persistent muellerian duct syndrome with undescended testis usually followed is orchiopexy without excising or partially excising the muellerian duct structures. Since the vas and vessels are intimately adhered to the fallopian tubes and body of the uterus, excision of muellerian duct structures is associated with devascularisation or injury to the vas. Following several reported incidences of malignancies in this residual muellerlan duct structures, we decided to excise them along with orchiopexy in this patient. In the literature there are evidences stating that malignancy could develop at any age ranging from a young boy to an old man. A careful and meticulous dissection avoiding electrocautery allowed excision of the muellerian duct structures without injury to the vas and vessels of the testes. The testes were brought down to the respective scrotal sac.

Quantification of contributions of different molecular fragments for antioxidant activity of coumarin derivatives based on QSAR analyses

Attempts have been made in the present work using in silico techniques for identification of essential structural features imparting antioxidant potential to naturally available coumarin molecules and their synthetic derivatives. Four different types of modeling tools have been employed for the qualitative and quantitative assessment of the molecular fragments constituting the biological pharmacophore. The descriptor-based quantitative structure–activity relationship (QSAR) and group-based QSAR (G-QSAR) models provide a quantitative estimation of the substituent requirements and the chemical nature of the parent moiety. Subsequently, 3D pharmacophore and hologram QSAR (HQSAR) models enable identification of the key molecular components necessary for the antioxidant potency to the molecules. All of the different models infer the importance of the hydrogen bond acceptor ketonic fragment for interaction of the antioxidant molecules with the neighbouring toxic radicals. Additionally, the phenyl substituent attached to the side chain and the benzene nucleus of the benzopyran moiety also constitute the response pharmacophore for the molecules under study. The models thus developed may serve as an essential query tool for screening of databases for selection of molecules bearing the essential fragments and subsequent prediction of their free radical scavenging potency.

Electrotopological state atom (E-state) index in drug design, QSAR, property prediction and toxicity assessment

Over the last two decades, a great deal of research has been oriented towards determination of correlation between molecular structures and a variety of responses exhibited by such molecules. Extensive attempts have been made to quantitatively determine the influence of structural fragments on the property profile of molecules through the development of quantitative structure-activity/property/toxicity relationship (QSAR/QSPR/QSTR) models based on regression analysis using different descriptors. Among all descriptors, the topological ones constitute an essential class encoding the crucial structural fragments governing the activity/property or toxicity data of the molecules. To better indicate the important topological features and molecular fragments mediating a particular response, Kier and Hall developed the electrotopological state atom (E-state) indices in the early 90s. The ability to encode the topology and electronic environment of molecular fragments in unison portrayed the E-state indices as an indispensable tool in the field of QSAR/QSPR/QSTR studies. This review looks back at different applications of E-state indices in the field of quantitative analysis of molecular properties as a function of their structures for diverse groups of molecules with vivid range of response parameters. The studies summarized here would help to understand potential of the E-state indices to identify the structural attributes responsible for various responses of the molecules. Although the present review includes most of the important researches carried out employing E-state parameters as the major group of descriptors over the last 15 years, the search is not exhaustive one. Apart from the studies reviewed here, several other researches have also been performed where the E-state indices have been engaged in association with several other descriptors to determine the influential molecular fragments for various endpoints.

Predictive Modeling of Antioxidant Coumarin Derivatives Using Multiple Approaches: Descriptor-Based QSAR, 3D-Pharmacophore Mapping, and HQSAR

The inability of the systemic antioxidants to alleviate the exacerbation of free radical formation from metabolic outputs and environmental pollutants claims an urgent demand for the identification and design of new chemical entities with potent antioxidant activity. In the present work, different QSAR approaches have been utilized for identifying the essential structural attributes imparting a potential antioxidant activity profile of the coumarin derivatives. The descriptor-based QSAR model provides a quantitative outline regarding the structural prerequisites of the molecules, while 3D pharmacophore and HQSAR models emphasize the favourable spatial arrangement of the various chemical features and the crucial molecular fragments, respectively. All the models infer that the fused benzene ring and the oxygen atom of the pyran ring constituting the parent coumarin nucleus capture the prime pharmacophoric features, imparting superior antioxidant activity to the molecules. The developed models may serve as indispensable query tools for screening untested molecules belonging to the class of coumarin derivatives.

In silico development, validation and comparison of predictive QSAR models for lipid peroxidation inhibitory activity of cinnamic acid and caffeic acid derivatives using multiple chemometric and cheminformatics tools

The design and development of antioxidant molecules have lately gained a great deal of focus which is attributed to their immense biomedicinal importance in combating the free radical associated health hazards. In a situation to replenish the endogenous antioxidant loss, synthetic molecules with potent antioxidant activity is demanded. The present work thus aims at in silico modeling of antioxidant molecules that may facilitate in searching and designing of new chemical entities with enhanced activity profile. A series of cinnamic acid and caffeic acid derivatives having the ability to inhibit lipid peroxidation have been modeled in the present work. Three different types of models were developed using different chemometric and cheminformatics tools to identify the essential structural attributes: (a) descriptor based QSAR models, (b) 3D pharmacophore models and (c) HQSAR (hologram QSAR) models. For the conventional QSAR modeling, descriptors belonging to different categories [quantum chemical descriptors (Mulliken charges of the common atoms of the molecules), thermodynamic descriptors, electronic descriptors, structural descriptors and spatial descriptors] were calculated for the development of statistically significant as well as well interpretable quantitative structure-activity relationship (QSAR) models. Two different chemometric tools [genetic function approximation (GFA) and genetic partial least squares (G/PLS)] were employed for the development of the QSAR models. The 3D pharmacophore model focused on the essential pharmacophoric features while the HQSAR model implicated the prime structural fragments that were necessitated for the optimal anti-lipid peroxidative activity of the molecules. All the models were validated based on internal, external and overall validation statistics. Randomization was performed in order to ensure the absence of chance correlation in the developed models. Among all models, the descriptor-based model developed using the GFA-spline technique yielded the most satisfactory results. The results obtained from all the models corroborate well with each other and chiefly signify the importance of the ketonic oxygen of the amide/ acid fragment and the ethereal oxygen substituted on the parent phenyl ring of the molecules under study. Thus the models can efficiently be utilized for extensive screening of large datasets and their subsequent activity prediction.