Performance evaluation of the SMG HHV-6 Q Real-Time PCR Kit for quantitative detection and differentiation of human herpesvirus 6A and 6B

The aim of this study was to compare the performance of the newly developed SMG HHV-6 Q Real-Time PCR Kit (SMG assay) with the RealStar HHV-6 PCR Kit (RealStar assay). The analytical sensitivity and specificity, linearity, and precision of the SMG assay were evaluated. The clinical performance of the SMG assay was assessed and compared with that of the RealStar assay using 207 clinical specimens (HHV-6A positive, n = 51; HHV-6B positive, n = 64; HHV-6A/B negative, n = 92). The limit of detection of the SMG assay was 2.92 log10 copies/mL for HHV-6A DNA and 2.88 log10 copies/mL for HHV-6B DNA. The linear range was determined to be 3.40-9.00 log10 copies/mL for both viruses. Intra- and inter-assay variability were below 5% at concentrations ranging from 4 to 9 log10 copies/mL. No cross-reactivity was observed with the 25 microorganisms included in the specificity panel. The clinical sensitivity and specificity of the SMG and RealStar assays compared to in-house polymerase chain reaction and sequencing were as follows: SMG assay, 98.0% and 100% for HHV-6A DNA, respectively, and 96.9% and 100% for HHV-6B DNA, respectively; RealStar assay, 98.0% and 100% for HHV-6A DNA, respectively, and 90.6% and 100% for HHV-6B DNA, respectively. The correlation coefficients between viral loads measured by the two assays were 0.948 and 0.975, with mean differences of 0.62 and 0.32 log10 copies/mL for HHV-6A and HHV-6B DNA, respectively. These results demonstrate that the SMG assay is a sensitive and reliable tool for the quantitative detection and differentiation of HHV-6A and HHV-6B DNA.IMPORTANCEQuantitative real-time PCR (qPCR) that can distinguish between HHV-6A and HHV-6B DNA is recommended for diagnosis of active infection. The SMG HHV-6 Q Real-Time PCR Kit (SMG assay) is a newly developed qPCR assay that can differentiate between HHV-6A and HHV-6B DNA; however, little is known about its performance. In this study, we assessed the performance of the SMG assay and compared it with that of a commercially available qPCR assay, the RealStar HHV-6 PCR Kit (RealStar assay). The SMG assay demonstrated excellent analytical sensitivity and specificity, precision, and linearity. Furthermore, the viral loads measured by the SMG assay were highly correlated with those measured by the RealStar assay. Our results suggest that the SMG assay is a useful diagnostic tool for quantitative detection and differentiation of HHV-6A and HHV-6B DNA.

False-positive Aspergillus galactomannan immunoassay in the glucose component of total parenteral nutrition products

IMPORTANCE

This manuscript describes an occurrence of false-positive GM tests in patients receiving TPN products from a manufacturer who had recently changed the supplier of the glucose component. We describe the clinical presentation of nine false-positive cases and the results of serologic and microbiological investigations of the TPN products suspected of contamination with GM. Attempts to detect GM in parenteral nutrition products were made since the detection of GM in sodium gluconate-containing solutions in 2007, but none of them identified the source of elevated GM indexes in TPN products. However, the present study demonstrated that the glucose component of the TPN products contained a high level of GM antigen, which caused false-positive GM assay results. The source of GM was glucoamylase, which was derived from A. niger in the manufacturing process. Physicians and clinical microbiology laboratories should be aware of this issue to improve interpretation and patient care.

Susceptibility to Fosfomycin and Nitrofurantoin of ESBL-Positive Escherichia coli and Klebsiella pneumoniae Isolated From Urine of Pediatric Patients

BACKGROUND

Pediatric urinary tract infection (UTI) caused by extended-spectrum β-lactamase (ESBL)-positive gram-negative bacilli (GNB) has limited options for oral antibiotic treatment. The purpose of this study was to investigate the susceptibility of ESBL-positive Escherichia coli and Klebsiella pneumoniae isolates from pediatric urine samples to two oral antibiotics (fosfomycin and nitrofurantoin).

METHODS

From November 2020 to April 2022, ESBL-positive E. coli and K. pneumoniae isolates from urine samples were collected at Samsung Medical Center, Seoul, Korea. Patients over 18 years of age or with malignancy were excluded. For repeated isolates from the same patient, only the first isolate was tested. Minimum inhibitory concentrations (MICs) were measured using agar (fosfomycin) or broth (nitrofurantoin) dilution methods. MIC50 and MIC90 were measured for fosfomycin and nitrofurantoin in both E. coli and K. pneumoniae.

RESULTS

There were 117 isolates from 117 patients, with a median age of 7 months (range, 0.0-18.5 years). Among 117 isolates, 92.3% (108/117) were E. coli and 7.7% (9/117) were K. pneumoniae. Isolates from the pediatric intensive care unit (PICU) and general ward (GW) was 11.1% (13/117) and 88.9% (104/117), respectively. Among 108 E. coli isolates, MIC50 and MIC90 for fosfomycin were 0.5 μg/mL and 2 μg/mL, respectively. Fosfomycin susceptibility rate was 97.2% (105/108) with a breakpoint of 128 μg/mL. Fosfomycin susceptibility rate was significantly lower in PICU isolates than in GW isolates (81.8% vs. 99.0%, P = 0.027). For nitrofurantoin, both the MIC50 and MIC90 were 16 μg/mL. Nitrofurantoin susceptibility rate was 96.3% (104/108) with a breakpoint of 64 μg/mL based on Clinical and Laboratory Standards Institute guidelines. Among the nine K. pneumoniae isolates, the MIC50 and MIC90 for fosfomycin was 2 μg/mL and 32 μg/mL, respectively. MIC50 and MIC90 for nitrofurantoin were 64 μg/mL and 128 μg/mL, respectively.

CONCLUSION

For uncomplicated UTI caused by ESBL-positive GNB in Korean children, treatment with fosfomycin and nitrofurantoin for E. coli infections can be considered as an effective oral therapy option.

Loop-mediated isothermal amplification assay for screening congenital cytomegalovirus infection in newborns

Congenital cytomegalovirus (CMV) infection is a common cause of sensorineural hearing loss and neurodevelopmental impairment in newborns. However, congenital CMV infection cannot be diagnosed using samples collected more than 3 weeks after birth because testing after this time cannot distinguish between congenital infection and postnatal infection. Herein, we developed a robust loop-mediated isothermal amplification (LAMP) assay for the large-scale screening of newborns for congenital CMV infection. In contrast to conventional quantitative polymerase chain reaction (qPCR), which detects CMV within a dynamic range of 1.0 × 106 to 1.0 × 102 copies/μL, our quantitative LAMP assay (qLAMP) detects CMV within a dynamic range of 1.1 × 108 to 1.1 × 103 copies/μL. Moreover, the turnaround time for obtaining results following DNA extraction is 90 min in qPCR but only 15 min in qLamp. The colorimetric LAMP assay can also detect CMV down to 1.1 × 103 copies/μL within 30 min, irrespective of the type of heat source. Our LAMP assay can be utilized in central laboratories as an alternative to conventional qPCR for quantitative CMV detection, or for point-of-care testing in low-resource environments, such as developing countries, via colorimetric naked-eye detection. KEY POINTS: • LAMP assay enables large-scale screening of newborns for congenital CMV infection. • LAMP allows colorimetric or quantitative detection of congenital CMV infection. • LAMP assay can be used as a point-of-care testing tool in low-resource environments.

Left Anterior Descending Coronary Artery-Optimized Knowledge-Based Radiotherapy Planning in Patients with Locally Advanced Non-Small Cell Lung Cancer

PURPOSE/OBJECTIVE(S)

The left anterior descending (LAD) coronary artery volume receiving 15 Gy (V15 Gy) has been associated with major adverse cardiac events and mortality in patients with locally advanced non-small cell lung cancer (LA-NSCLC) treated with radiotherapy (RT). However, coronary arteries are not routinely contoured as standard-of-care and there is limited data describing coronary-sparing planning techniques. Our objective was to evaluate whether LAD-sparing could be improved compared to real-world plans using a commercial knowledge-based planning (KBP) software without clinically unacceptable tradeoffs to other critical organs at risk (OAR).

MATERIALS/METHODS

Retrospective replanning analysis was conducted on 31 RT plans developed for patients with LA-NSCLC. Each case was manually replanned with volumetric modulated arc radiotherapy (VMAT) optimized for LAD V15 Gy sparing with a prescription dose of 60 Gy. The resulting plans were used to create an LAD-optimized KBP model. The model included both KBP-generated objectives and additional point objectives to meet LAD (V15 Gy < 10%), lung (V5 Gy < 60%, V20 < 30%, mean < 17 Gy), heart (mean < 20 Gy), spinal cord (D0.03cc < 45 Gy), esophagus (V60 Gy < 17%, mean < 34 Gy), and planning target volume (PTV; D95% = 100%). The LAD-optimized model was deployed to replan 33 additional VMAT plans for LA-NSCLC with prescription dose 60 Gy, delivered between 2018 and 2022. Dose constraints or objectives were only unmet with KBP when not met in the original plan. Descriptive statistics were used to compare dosimetric parameters between original and LAD-optimized KBP plans.

RESULTS

For the 33 plans identified for LAD-optimized KBP replanning, the original plans had a mean LAD V15 Gy of 17.9% (standard error [SE], 3.9%), while the LAD-optimized KBP plans had a significantly lower mean LAD V15 Gy of 5.9% (SE, 1.9%; p = 0.031). There was no significant difference in mean heart dose between the original and LAD-optimized KBP plans (8.4 Gy [SE 6.6 Gy] vs. 7.3 Gy [SE 5.8 Gy]; p = 0.48). Of these 33 KBP plans, 42% (n = 14) had mean reductions in LAD V15 Gy from 40.5% (SE 4.3%) to 10.5% (SE 3.5%; p = 0.0002), with 9/14 now able to meet < 10%, without affecting other critical OAR objectives (p > 0.5 for lungs, esophagus, spinal cord). 45% (n = 15) originally had an LAD V15 Gy < 1%, which were unchanged using KBP (p > 0.3). Four plans (12%) had higher LAD V15 Gy in the KBP vs. original plan (2/4 still meeting < 10%), due to the model prioritizing other OARs to a greater degree.

CONCLUSION

Improvements in LAD-sparing was achievable in more than 40% of plans without apparent clinically significant tradeoffs in other critical OARs and without corresponding change in MHD. This result underscores the importance of standard implementation of LAD contouring and dose constraints, particularly given the discordance between whole heart and LAD dose exposure.

COVID-19 Vaccination Status Among Korean Pediatric Population With Comorbidities

The pediatric population with comorbidities is a high-risk group for severe coronavirus disease 2019 (COVID-19). As of January 2023, the COVID-19 vaccination rate for at least two doses among Korean children 5-11 years is low at 1.1%. We summarized the COVID-19 vaccination status for the pediatric population (5-17 years) with comorbidities through July 2022 using the National Health Insurance Service database. Pediatric patients with comorbidities had higher vaccination rates than the general pediatric population (2.4% vs. 1.1% in 5-11-year-olds [P < 0.001], 76.5% vs. 66.1% in 12-17-year-olds [P < 0.001]). However, there were substantial differences according to comorbidity category, and the 2-dose vaccination rate was lowest among children with immunodeficiency in all age groups (1.1% in 5-11-year-olds, 51.2% in 12-17-year-olds). The COVID-19 vaccination rate among Korean children has remained stagnant at a low proportion despite ongoing outreach. Thus, more proactive strategies are needed alongside continuous surveillance.

A27 DNA HYPOMETHYLATION INDUCED BY 5-AZA-CDR OR LOSS OF DNMT1 INHIBITS COLITIS-ASSOCIATED COLORECTAL CANCER

Background

Colorectal cancer is the second leading cause of cancer death in Canada. A major risk factor for the development of colorectal cancer is chronic inflammation leading to colitis-associated cancer (CAC). We previously described a CAC mouse model in which tumors arise from DCLK1+ tuft cells following loss of the tumor suppressor adenomatous polyposis coli (APC) and induction of colitis. Interestingly, both colitis and CAC display epigenetic changes that modulate gene expression. However, the impact of DNA methylation changes on colonic tumorigenesis is not known. Thus, we hypothesize that inhibition of DNA methylation in DCLK1+ tuft cells reduces colonic tumorigenesis.

Purpose

In this study, we aim to investigate the role of DNA methylation in CAC by inhibiting DNA methylation using genetic and pharmacologic means.

Method

Using a publicly available dataset (GSE75214) of gene expression data analyzed by microarray from colonic biopsies of patients with ulcerative colitis and Crohn’s Disease with active disease, we examined the expression of DNA methyltransferases (DNMTs). Expression of DNMTs in mice with colitis was additionally examined by RT-qPCR and global DNA methylation levels measured by 5-mC ELISA. In separate experiments, Dclk1-CreERT2/Apc^f/f mice were crossed to DNMT1^f/f mice to knock-out the DNA methyltransferase DNMT1 in DCLK1+ tuft cells. Dclk1/Apc^f/f and Dclk1/Apc^f/f/DNMT1^f/f mice were then administered three doses of tamoxifen followed by 2.5% dextran sodium sulfate (DSS) for five days to induce colitis. Fourteen weeks later, we assessed colonic tumor number and size. In a separate cohort of Dclk1/Apc^f/f mice, we induced colitis and treated the mice with six doses of the DNA de-methylating drug 5-AZA-2’-deoxycytidine (5-AZA) or vehicle, and assessed colonic tumor number. To examine DNA methylation changes, we then treated WT mice with 5-AZA and DSS and isolated intestinal epithelial cells. From the intestinal epithelial cell, we isolated DNA and ran the Infinium MouseMethylation BeadChip Array.

Result(s)

Patients with IBD were found to have increased expression of DNMT1 compared to healthy controls. Mice treated with DSS similarly had increased DNMT1 expression, as well as, global methylation levels compared to controls. Deletion of DNMT1 in DCLK1+ cells significantly inhibited the number and size of colonic tumors. Treatment of mice with 5-AZA decreased global and gene specific DNA methylation levels, and significantly reduced both the number of mice with tumors, and the average colonic tumor number and size per mouse.

Conclusion(s)

Our findings demonstrate that colitis in both patients and mice is associated with DNA methylation. Furthermore, DNA hypomethylation by 5-AZA treatment or loss of DNMT1 reduces CAC formation suggesting that altered DNA methylation plays a critical role in colonic tumorigenesis.

Disclosure of Interest

None Declared

Vaccine Effect on Household Transmission of Omicron and Delta SARS-CoV-2 Variants

BACKGROUND

We evaluated the household secondary attack rate (SAR) of the omicron and delta severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, according to the vaccination status of the index case and household contacts; further, in vaccinated index cases, we evaluated the effect of the antibody levels on household transmission.

METHODS

A prospective cross-sectional study of 92 index cases and 197 quarantined household contacts was performed. Tests for SARS-CoV-2 variant type and antibody level were conducted in index cases, and results of polymerase chain reaction tests (during the quarantine period) were collected from contacts. Association of antibody levels in vaccinated index cases and SAR was evaluated by multivariate regression analysis.

RESULTS

The SAR was higher in households exposed to omicron variant (42%) than in those exposed to delta variant (27%) (P = 0.040). SAR was 35% and 23% for unvaccinated and vaccinated delta variant exposed contacts, respectively. SAR was 44% and 41% for unvaccinated and vaccinated omicron exposed contacts, respectively. Booster dose immunisation of contacts or vaccination of index cases reduced SAR of vaccinated omicron variant exposed contacts. In a model with adjustment, anti-receptor-binding domain antibody levels in vaccinated index cases were inversely correlated with household transmission of both delta and omicron variants. Neutralising antibody levels had a similar relationship.

CONCLUSION

Immunisation of household members may help to mitigate the current pandemic.

POS0217 ALL-CAUSE AND CAUSE SPECIFIC MORTALITY AMONG PATIENTS WITH BEHCET’S DISEASE VERSUS GENERAL POPULATION

Background

Behcet’s disease (BD) is a systemic vasculitis with multiorgan involvement.

Objectives

To compare the risk of all-cause and cause specific mortality among patients with BD compared to general population

Methods

Using the 2002-2017 Korea National Health Insurance database, we conducted a cohort study among BD patients compared to general population matched on age and sex at a 1:5 ratio. The primary outcome was death of any cause, and the secondary outcomes were cause-specific mortality for top 5 causes of death. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), comparing BD patients versus general population.

Results

The PS-matched study cohort (mean age 42.1 years; 32.0% male) included 32288 BD patients and 161440 controls. During a mean follow-up of 9.6 years, 2214 deaths occurred. The HR [95%] for all-cause mortality was 10.6 [9.6-11.6]. The Top 5 causes of death derived from malignancy, cardiovascular disease, infection, respiratory disease, and injury: the HR [95%] for mortality from these causes were 8.5 [7.2-10.1], 10.8 [8.6-13.6], 14.6 [8.1-26.3], 12.0 [8.5-17.0], and 8.0 [5.0-13.0], respectively.

Conclusion

This population-based cohort study warns exceptionally heavy burden of the disease showing approximately 10 times higher mortality of BD patients compared to general population. In line with this, risk of cause specific mortality was also significantly higher among the BD patients, for 5 top causes of death.

Disclosure of Interests

None declared

POS0282 UPDATE ON COMPARATIVE CARDIOVASCULAR SAFETY OF FEBUXOSTAT VERSUS ALLOPURINOL AMONG PATIENTS WITH GOUT

Background

Gout is associated with an increased risk of cardiovascular (CV) disease.

Objectives

To update comparative CV safety of febuxostat versus allopurinol among patients with gout

Methods

Using the 2011-2019 Korea National Health Insurance database, we conducted a cohort study comparing gout patients initiating febuxostat versus allopurinol, with study participants matched on a propensity score (PS) for>60 covariates at a 1:1 ratio. The primary outcome was composite CV outcome of myocardial infarction, coronary revascularization, and stroke. Secondary outcomes were CV and all-cause mortalities in addition to individual components of the primary outcome. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), comparing febuxostat versus allopurinol initiators.

Results

We included 160,930 febuxostat users PS-matched on 160,930 allopurinol users (mean age 59.3 years, 79.6% male). During a mean follow-up of 250 days, the incidence rate of the primary outcome was 2.27 and 2.06 per 100 person-years for allopurinol and febuxostat users respectively, with the PS-matched HR [95% CI] of 1.03 [0.95-1.12]. Analysis on secondary outcomes also showed a similar result except for all-cause mortality with a significantly reduced risk among febuxostat users with a PS-matched HR [95% CI] of 0.84 [0.78-0.91] (Table 1).

Table 1.

Comparative cardiovascular safety between febuxostat and allopurinol

Febuxostat N = 160,930Allopurinol (Ref) N= 160,930HR (95% CI)EventsPYaIR [95% CI]EventsPYaIR(95% CI]Composite CV endpoint2635128,1932.06 [1.98-2.13]2,09992,5122.27 [2.17-2.37]1.03 [0.95-1.12]MI468129,8730.36 [0.33-0.39]34193,8080.36 [0.33-0.40]1.13 [0.91-1.39]Coronary revascularization1085129,2330.84 [0.79-0.89]85693,2930.92 [0.86-0.98]1.10 [0.96-1.26]Stroke or TIA1490129,1631.15 [1.10-1.21]1,18793,2521.27 [1.20-1.35]0.99 [0.90-1.10]Death2558130,1761.97 [1.89-2.04]2,20194,0072.34 [2.24-2.44]0.84 [0.78-0.91]

aIR is per 100 person-years. IR=incidence rate, HR=hazard ratio, CI=confidence interval, MI=myocardial infarction, PY=person-years, TIA=transient ischemic attack

Conclusion

This large population-based cohort study showed a similar CV safety profile between febuxostat and allopurinol users but found a 16% reduced all-cause mortality among febuxostat users compared to allopurinol, primarily derived from non-CV death reduction.

Disclosure of Interests

None declared

Antibody level predicts the clinical course of breakthrough infection of COVID-19 caused by delta and omicron variants: a prospective cross-sectional study

Background

Omicron variant viruses spread rapidly, even in individuals with high vaccination rates. This study aimed to determine the utility of the antibody against spike protein level as a predictor of the disease course of coronavirus disease 2019 (COVID-19) in vaccinated patients.

Methods

Between December 11, 2021, and February 10, 2022, we performed a prospective observational cohort study in South Korea, which included patients infected with Delta and Omicron variants. A multivariable logistic regression analysis to determine the association between antibody levels and outcomes was conducted. The relationship between antibody levels and cycle threshold (Ct) values was confirmed using a generalized linear model.

Results

From 106 vaccinated patients (39 Delta and 67 Omicron), the geometric mean titers of antibodies in patients with fever (≥37.5°C), hypoxia (≤94% of SpO₂), pneumonia, C-reactive protein (CRP) elevation (>8 mg/L), or lymphopenia (<1100 cells/μL) were 1201.5 U/mL, 98.8 U/mL, 774.1 U/mL, 1335.1 U/mL, and 1032.2 U/mL, respectively. Increased antibody levels were associated with a decrease in the occurrence of fever (adjusted odds ratio [aOR], 0.23; 95% CI, 0.12–0.51), hypoxia (aOR, 0.23; 95% CI, 0.08–0.7), CRP elevation (aOR, 0.52; 95% CI, 0.29–0.0.94), and lymphopenia (aOR, 0.57; 95% CI, 0.33–0.98). Ct values showed a positive correlation between antibody levels (P = .02).

Conclusions

Antibody levels are predictive of the clinical course of COVID-19 in vaccinated patients with Delta and Omicron variant infections. Our data highlight the need for concentrated efforts to monitor patients with severe acute respiratory syndrome coronavirus 2 infection who are at risk of low antibody levels.

Examining the multilevel associations between psychological wellbeing and social trust: A primary analysis of survey data

The present study examines the associations between multiple measures of social trust and two outcomes of psychological wellbeing (happiness and depression) among South Korean adults (n = 1549) living in residential communities, that is, administrative districts (n = 77) in and around the capital city of Seoul. Based on multilevel modeling, we find that familial trust positively predicts happiness at both individual and contextual levels; and it negatively predicts depression at the individual level only. In comparison, peer trust is negatively related only to depression at the individual level, albeit marginally. Lastly, general trust significantly predicts both outcomes at the community, but not individual, level. These mixed findings suggest that the trust-wellbeing relationship depends critically on issues of definition (how the variables are conceptualized) and measurement (how they are operationalized according to different units of analysis). Our study offers implications for the literature on social determinants of mental health broadly and, more specifically, on the role of social trust.

Comparative risk of osteoporotic fracture among patients with rheumatoid arthritis receiving TNF inhibitors versus other biologics: a cohort study

In this population-based cohort study on comparative osteoporotic fracture risks between different biologic disease-modifying drugs among patients with rheumatoid arthritis (RA), we did not find a significant difference in the risk of osteoporotic fractures between RA patients receiving TNF inhibitors versus abatacept or tocilizumab.

INTRODUCTION

We aimed to investigate the comparative risk of osteoporotic fractures between rheumatoid arthritis (RA) patients who initiated TNF inhibitors (TNFis) versus abatacept or tocilizumab.

METHODS

Using the Korea National Health Insurance Service datasets from 2002 to 2016, RA patients who initiated TNFis, abatacept, or tocilizumab were identified. The primary outcome was a composite end point of non-vertebral fractures and hospitalized vertebral fractures; secondary outcomes were two components of the primary outcome and fractures occurring at the humerus/forearm. Propensity score (PS) matching with a variable ratio up to 10 TNFi initiators per 1 comparator drug initiator was used to adjust for > 50 baseline confounders. We estimated hazard ratios (HRs) and 95% confidence interval (CI) of fractures comparing TNFi initiators to abatacept and to tocilizumab by Cox proportional hazard models stratified by a matching ratio.

RESULTS

After PS-matching, 2307 TNFi initiators PS-matched on 588 abatacept initiators, and 2462 TNFi initiators on 640 tocilizumab initiators were included. A total of 77 fractures occurred during a mean follow-up of 454 days among TNFi and abatacept initiators and 83 fractures during 461 days among TNFi and tocilizumab initiators. The PS-matched HR (95% CI) was 0.91 (0.48-1.71) comparing TNFi versus abatacept initiators, and 1.00 (0.55-1.83) comparing TNFi versus tocilizumab initiators. Analysis on vertebral and non-vertebral fractures showed similar results.

CONCLUSIONS

In this nationally representative cohort, we did not find a significant difference in the risk of fractures between TNFi initiators versus abatacept or tocilizumab among RA patients.

THU0178 PREDICTORS OF BIOLOGIC DISEASE MODIFYING ANTI-RHEUMATIC DRUG INITIATION AMONG PATIENTS WITH RHEUMATOID ARTHRITIS IN KOREA

Background:

Biological disease-modifying anti-rheumatic drugs (bDMARDs) have significantly improved clinical prospects for patients with rheumatoid arthritis (RA).

Objectives:

To identify predictors of bDMARDs initiation in RA patients.

Methods:

Using 2002-2016 Korea National Health Insurance Service database, we conducted a nested case-control study on RA patients. Four conventional DMARD (cDMARD) users were selected by risk set sampling per each bDMARD user, matched on the calendar year/month of RA diagnosis. Potential predictors were separately assessed for two periods, 1 year after RA diagnosis and 1 year prior to bDMARD initiation, by logistic regression analyses estimating odds ratio (OR) and 95% confidence interval (CI).

Results:

The study included 27,940 cDMARD users and 6,985 bDMARD users. Younger age, initial use of a less potent cDMARD (sulfasalazine), corticosteroid use, and higher maximal methotrexate (MTX) dose during 1 year post-diagnosis were positive predictors for later bDMARD initiation, while male gender, initial use of a potent cDMARD (MTX, leflunomide, or tacrolimus), initial MTX dose of ≥10mg/wk, and initial cDMARD combination were negative predictors (Table 1). Use of non-MTX DMARDs (leflunomide, sulfasalazine, or tacrolimus), higher # of cDMARD used, subcutaneous administration of MTX, corticosteroid therapy, and higher maximal MTX dose were positive predictors of subsequent bDMARD. Although higher comorbidity score during 1 year before bDMARD initiation was a positive predictor, the effect was heterogenous by involved systems (Table 2).

Table 1.

Predictors of bDMARD initiation among RA patients during 1-year post-diagnosis

PredictorsOR(95% CI)P-valueAge (/1 year)0.977(0.974-0.980)<0.001Sex (male vs. female)0.850(0.787-0.918)<0.0011st cDMARD at RA diagnosis (yes vs. no) Methotrexate0.540(0.476-0.614)<0.001 Leflunomide0.463(0.388-0.552)<0.001 Sulfasalazine1.305(1.197-1.424)<0.001 Tacrolimus0.181(0.083-0.395)<0.001Initial MTX dose (≥10mg/week vs. <10mg/week)0.539(0.506-0.575)<0.001Initial cDMARD combination (yes vs. no)0.621(0.530-0.727)<0.001Subcutaneous MTX use (yes vs. no)1.456(1.156-1.834)0.001Maximal MTX dose (/1mg)1.012(1.008-1.016)<0.001Corticosteroids use (yes vs. no)2.805(2.345-3.355)<0.001Table 2.

Predictors of bDMARD initiation among RA patients during 1-year prior to bDMARD initiation

PredictorsOR(95% CI)P-valueAge (/1 year)0.970(0.967-0.974)<0.001Non-MTX cDMARD use (yes vs. no)1 Leflunomide1.765(1.573-1.980)<0.001 Sulfasalazine1.465(1.297-1.654)<0.001 Tacrolimus2.070(1.796-2.387)<0.001 Subcutaneous MTX use (yes vs. no)1.731(1.577-1.900)<0.001Maximal MTX dose (/1mg)2.568(1.921-3.433)<0.001Glucocorticoid use (yes vs. no)1.015(1.010-1.021)<0.001Comorbidity index (/1 point)1.124(1.076-1.175)<0.001Individual comorbidities (yes vs. no) Stroke/ transient ischemic attack0.764(0.626-0.932)0.008 Atrial fibrillation0.666(0.455-0.973)0.036 Diabetes mellitus1.208(1.076-1.356)0.001 Joint replacement therapy1.788(1.341-2.384)<0.001 Hepatitis B infection1.559(1.238-1.964)<0.001 Hepatitis C infection2.117(1.532-2.925)<0.001 Chronic obstructive pulmonary disease1.118(1.012-1.234)0.028

1MTX was excluded since all bDMARD initiators were required to use MTX before bDMARD initiation.

Conclusion:

In this population-based nationwide study, we identified period-specific predictors of bDMARD initiation among RA patients in Korea. Overall, initial aggressive RA treatment after RA diagnosis were associated with less use of later bDMARD, while highly intensive therapy observed just before bDMARD initiation reflects refractory nature of RA during this period.

Disclosure of Interests:

None declared

FRI0067 ALL-CAUSE AND CAUSE-SPECIFIC MORTALITY OF PATIENTS WITH RHEUMATOID ARTHRITIS IN KOREA: A NATION-WIDE POPULATION-BASED STUDY

Background:

Rheumatoid arthritis (RA) is a chronic inflammatory disease associated with excess mortality.

Objectives:

To compare all-cause and cause-specific mortality between RA patients versus general population, using a nationally representative cohort from Korea National Health Insurance Service database (KNHIS).

Methods:

Patients with RA aged ≥ 40 years were identified from 2010-2016 KNHIS database and their annual cohorts were constructed per each calendar year. RA patients of each cohort were required to have prevalent RA on January 1stof the given calendar year. The KNHIS were linked with Korea national mortality data to obtain cause of death information and to estimate expected deaths of RA patients in reference to mortality data of the general population in Korea. Standardized mortality ratio (SMR) with a 95% confidence interval (CI) was calculated to compare mortality of RA patients and general population.

Results:

A total of 6,404 deaths occurred among 79,440 RA patients during 2011-2016 period, showing all-cause SMR (95% CI) of 1.45 (1.42-1.49) compared to general population. The SMR was 1.72 (1.59-1.85) for biologics users and 1.43 (1.39-1.46) for non-users, versus general population. The annual SMR of RA patients showed a growing trend of mortality over time particularly among biologics users (Table 1). The SMRs for common causes of death among RA patients showed approximately tripled risk of dying due to pulmonary and infectious causes compared to general population (Table 2). There was approximately 20% increased risk of cardiovascular deaths but 8% decreased risk of cancer-related deaths among RA patients compared to general population (Table 2).

Table 1.

Annual all-cause SMR of RA patients compared to 2010 general population

Calendar year1RA patientsBiologics usersBiologics non-users20111.00 (0.92−1.07)1.13 (0.87−1.39)0.98 (0.90−1.06)20121.13 (1.06−1.21)0.98 (0.75−1.22)1.15 (1.07−1.23)20131.22 (1.14−1.30)1.29 (1.04−1.54)1.21 (1.13−1.29)20141.30 (1.23−1.38)1.53 (1.26−1.79)1.28 (1.20−1.36)20151.45 (1.38−1.53)1.81 (1.53−2.09)1.41 (1.33−1.50)20161.45 (1.37−1.52)1.94 (1.66−2.22)1.39 (1.31−1.47)

CI, confidence interval; RA, rheumatoid arthritis; SMR, standardized mortality ratio

12010 data were used to identify RA diagnosis dates but were not included for SMR estimation since diagnosis dates of RA were unclear for those who had RA in 2010.

Table 2.

Cause-specific SMR comparing RA patients versus general population

Cause of deathRA patientsBiologics usersBiologics non-usersInfection3.12 (2.93−3.13)4.12 (3.36−4.88)3.03 (2.83−3.23)Cancer0.92 (0.87−0.97)0.98 (0.81−1.14)0.91 (0.85−0.96)Respiratory13.14 (2.97−3.32)4.64 (3.89−5.38)3.01 (2.83−3.19)Cardiovascular21.18 (1.12−1.25)1.26 (1.03−1.50)1.18 (1.11−1.25)

CI, confidence interval; RA, rheumatoid arthritis; SMR, standardized mortality ratio

1Includes pulmonary infections and chronic lung diseases (J00-J98, U04);2Includes atherosclerotic and non-atherosclerotic deaths (I00-I99).

Conclusion:

The all-cause mortality of RA patients during 2011-2016 was overall 45% greater than that of general Korean population, which increased annually over the study period. The increased mortality was more prominent among biologics users than non-users. The risk of infectious and respiratory deaths were tripled among RA patients compared to general population.

References:

[1]Sokka T, et al. Mortality in rheumatoid arthritis: 2008 update. Clin Exp Rheumatol. 2008;26(5 Suppl 51):S35-61.

Acknowledgments:

None

Disclosure of Interests:

None declared

Systematic review and meta-analysis: Efficacy of patented probiotic, VSL#3, in irritable bowel syndrome

BACKGROUND

VSL#3 is a patented probiotic for which several clinical trials suggest benefits on motor function, bloating, and symptoms of irritable bowel syndrome (IBS).

OBJECTIVES

To quantify effects of VSL#3 on abdominal pain, stool consistency, overall response, abdominal bloating, and quality of life (QOL) in IBS through meta-analysis.

METHODS

MEDLINE (OvidSP and PubMed), EMBASE, Web of Science, and Scopus were searched up to May 2017. Using a fixed effects model, we pooled data from intention-to-treat analyses of randomized trials (RCTs) comparing VSL#3 to placebo in IBS. Data were reported as relative risk (RR), overall mean difference (MD), or standardized MD (SMD) with 95% confidence intervals (CI). Quality of evidence was rated using the GRADE approach.

KEY RESULTS

Among 236 citations, 5 RCTs (243 patients) were included. No significant differences were observed for abdominal pain (SMD = -0.03; 95% CI -0.29 to 0.22), bloating (SMD = -0.15; 95% CI -0.40 to 0.11), proportion of bowel movements with normal consistency (overall MD = 0; 95% CI -0.09 to 0.08), or IBS-QOL (SMD = 0.08; 95% CI -0.22 to 0.39). VSL#3 was associated with a nearly statistically significant increase in overall response (RR = 1.39; 95% CI 0.99-1.98).

CONCLUSIONS & INFERENCES

In this systematic review and meta-analysis, there was a trend toward improvement in overall response with VSL#3, but no clear evidence effectiveness for IBS. However, the number and sample sizes of the trials are small and the overall quality of evidence for 3 of the 5 outcomes was low. Larger trials evaluating validated endpoints in well-defined IBS patients are warranted.

Functional Roles of Aromatic Residues and Helices of Papiliocin in its Antimicrobial and Anti-inflammatory Activities

A cecropin-like peptide, papiliocin, isolated from the swallowtail butterfly Papilio xuthus, possesses high selectivity against gram-negative bacteria. Since Trp(2) and Phe(5) are highly conserved residues in cecropin-like peptides, we investigated the role of Trp(2) and Phe(5) in antibacterial activity. Substitution of Trp(2) and Phe(5) in papiliocin with Ala (papiliocin-2A and papiliocin-5A) revealed that Trp(2) is a key residue in its antibacterial activities. In order to understand the structural requirements for papiliocin function and to design shorter, but more potent, peptide antibiotics, we designed papiliocin constructs, PapN (residues Arg(1)-Ala(22) from the N-terminal amphipathic helix). PapN exhibited significant broad-spectrum antibacterial activities without cytotoxicity. Bactericidal kinetics of peptides against E.coli showed that papiliocin completely and rapidly killed E.coli in less than 10 minutes at 2× MIC concentration, while papiliocin-2A and papiliocin-5A killed four times more slowly than papiliocin. The PapN series peptides permeabilized bacterial membranes less effectively than papiliocin, showing no antibacterial activities in an hour. The results imply that the Trp(2) and Phe(5) in the amphipathic N-terminal helix are important in the rapid permeabilization of the gram-negative bacterial membrane. The hydrophobic C-terminal residues permeabilize the hydrophobic bacterial cell membrane synergistically with these aromatic residues, providing selectivity against gram-negative bacteria.

Association between information provision and decisional conflict in cancer patients

BACKGROUND

In this study, we aimed to identify demographic and clinical variables that correlate with perceived information provision among cancer patients and determine the association of information provision with decisional conflict (DC).

PATIENTS AND METHODS

We enrolled a total of 625 patients with cancer from two Korean hospitals in 2012. We used the European Organization for Research and Treatment of Cancer (EORTC) quality-of-life questionnaire (QLQ-INFO26) to assess patients' perception of the information received from their doctors and the Decisional Conflict Scale (DCS) to assess DC. To identify predictive sociodemographic and clinical variables for adequate information provision, backward selective logistic regression analyses were conducted. In addition, adjusted multivariate logistic regression analyses were carried out to identify clinically meaningful differences of perceived level of information subscales associated with high DC.

RESULTS

More than half of patients with cancer showed insufficient satisfaction with medical information about disease (56%), treatment (73%), other services (83%), and global score (80%). In multiple logistic regression analyses, lower income and education, female, unmarried status, type of cancer with good prognosis, and early stage of treatment process were associated with patients' perception of inadequate information provision. In addition, Information about the medical tests with high DCS values clarity [adjusted odds ratio (aOR), 0.54; 95% confidence interval (CI) 0.30-0.97] and support (aOR, 0.53; 95% CI 0.33-0.85) showed negative significance. For inadequate information perception about treatments and other services, all 5 DCS scales (uncertainty, informed, values clarity, support, and effective decision) were negatively related. Global score of inadequate information provision also showed negative association with high DCS effective decision (aOR, 0.43; 95% CI 0.26-0.71) and DCS uncertainty (aOR, 0.46; 95% CI 0.27-0.77).

CONCLUSION

This study found that inadequate levels of perceived information correlated with several demographic and clinical characteristics. In addition, sufficient perceived information levels may be related to low levels of DC.

Peptoid-Substituted Hybrid Antimicrobial Peptide Derived from Papiliocin and Magainin 2 with Enhanced Bacterial Selectivity and Anti-inflammatory Activity

Antimicrobial peptides (AMPs) are important components of the host innate immune system. Papiliocin is a 37-residue AMP purified from larvae of the swallowtail butterfly Papilio xuthus. Magainin 2 is a 23-residue AMP purified from the skin of the African clawed frog Xenopus laevis. We designed an 18-residue hybrid peptide (PapMA) incorporating N-terminal residues 1-8 of papiliocin and N-terminal residues 4-12 of magainin 2, joined by a proline (Pro) hinge. PapMA showed high antimicrobial activity but was cytotoxic to mammalian cells. To decrease PapMA cytotoxicity, we designed a lysine (Lys) peptoid analogue, PapMA-k, which retained high antimicrobial activity but displayed cytotoxicity lower than that of PapMA. Fluorescent dye leakage experiments and confocal microscopy showed that PapMA targeted bacterial cell membranes whereas PapMA-k penetrated bacterial cell membranes. Nuclear magnetic resonance experiments revealed that PapMA contained an N-terminal α-helix from Lys(3) to Lys(7) and a C-terminal α-helix from Lys(10) to Lys(17), with a Pro(9) hinge between them. PapMA-k also had two α-helical structures in the same region connected with a flexible hinge residue at Nlys(9), which existed in a dynamic equilibrium of cis and trans conformers. Using lipopolysaccharide-stimulated RAW264.7 macrophages, the anti-inflammatory activity of PapMA and PapMA-k was confirmed by inhibition of nitric oxide and inflammatory cytokine production. In addition, treatment with PapMA and PapMA-k decreased the level of ultraviolet irradiation-induced expression of genes encoding matrix metalloproteinase-1 (MMP-1), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in human keratinocyte HaCaT cells. Thus, PapMA and PapMA-k are potent peptide antibiotics with antimicrobial and anti-inflammatory activity, with PapMA-k displaying enhanced bacterial selectivity.

Anti-inflammatory activities of cecropin A and its mechanism of action

Cecropin A is a novel 37-residue cecropin-like antimicrobial peptide isolated from the cecropia moth, Hyalophora cecropia. We have demonstrated that cecropin A is an antibacterial agent and have investigated its mode of action. In this study, we show that cecropin A has potent antimicrobial activity against 2 multidrug resistant organisms-Acinetobacter baumanii and-Pseudomonas aeruginosa. Interactions between cecropin A and membrane phospholipids were studied using tryptophan blue shift experiments. Cecropin A has a strong interaction with bacterial cell mimetic membranes. These results imply that cecropin A has selectivity for bacterial cells. To address the potential the rapeutic efficacy of cecropin A, its anti-inflammatory activities and mode of action in mouse macrophage-derived RAW264.7 cells stimulated with lipopolysaccharide (LPS) were examined. Cecropin A suppressed nitrite production, mTNF-α, mIL-1β, mMIP-1, and mMIP-2 cytokine release in LPS-stimulated RAW264.7 cells. Furthermore, cecropin A inhibited intracellular cell signaling via the ERK, JNK, and p38 MAPK pathway, leading to the prevention of COX-2 expression in LPS-stimulated RAW264.7 cells. These results strongly suggest that cecropin A should be investigated as a potential agent for the prevention and treatment of inflammatory diseases.

Role of phenylalanine and valine10 residues in the antimicrobial activity and cytotoxicity of piscidin-1

Piscidin-1 (Pis-1) is a linear antibacterial peptide derived from mast cells of aquacultured hybrid striped bass that comprises 22 amino acids with a phenylalanine-rich amino-terminus. Pis-1 exhibits potent antibacterial activity against pathogens but is not selective for distinguishing between bacterial and mammalian cells. To determine the key residues for its antibacterial activity and those for its cytotoxicity, we investigated the role of each Phe residue near the N-terminus as well as the Val¹⁰ residue located near the boundary of the hydrophobic and hydrophilic sectors of the helical wheel diagram. Fluorescence dye leakage and tryptophan fluorescence experiments were used to study peptide-lipid interactions, showing comparable depths of insertion of substituted peptides in different membranes. Phe² was found to be the most deeply inserted phenylalanine in both bacterial- and mammalian-mimic membranes. Each Phe was substituted with Ala or Lys to investigate its functional role. Phe² plays key roles in the cytotoxicity as well as the antibacterial activities of Pis-1, and Phe⁶ is essential for the antibacterial activities of Pis-1. We also designed and synthesized a piscidin analog, Pis-V10K, in which Lys was substituted for Val¹⁰, resulting in an elevated amphipathic α-helical structure. Pis-V10K showed similar antibacterial activity (average minimum inhibitory concentration (MIC)  = 1.6 µM) to Pis-1 (average MIC  = 1.5 µM). However, it exhibited much lower cytotoxicity than Pis-1. Lys¹⁰-substituted analogs, Pis-F1K/V10K, Pis-F2K/V10K, and Pis-F6K/V10K in which Lys was substituted for Phe retained antibacterial activity toward standard and drug-resistant bacterial strains with novel bacterial cell selectivity. They exert anti-inflammatory activities via inhibition of nitric oxide production, TNF-α secretion, and MIP-1 and MIP-2 production. They may disrupt the binding of LPS to toll-like receptors, eventually suppressing MAPKs-mediated signaling pathways. These peptides may be good candidates for the development of peptide antibiotics with potent antibacterial activity but without cytotoxicity.

Binding model for eriodictyol to Jun-N terminal kinase and its anti-inflammatory signaling pathway

The anti-inflammatory activity of eriodictyol and its mode of action were investigated. Eriodictyol suppressed tumor necrosis factor (mTNF)-α, inducible nitric oxide synthase (miNOS), interleukin (mIL)-6, macrophage inflammatory protein (mMIP)-1, and mMIP-2 cytokine release in LPS-stimulated macrophages. We found that the anti-inflammatory cascade of eriodictyol is mediated through the Toll-like Receptor (TLR)4/CD14, p38 mitogen-activated protein kinases (MAPK), extracellular-signalregulated kinase (ERK), Jun-N terminal kinase (JNK), and cyclooxygenase (COX)-2 pathway. Fluorescence quenching and saturation-transfer difference (STD) NMR experiments showed that eriodictyol exhibits good binding affinity to JNK, 8.79 × 10⁵ M^-1. Based on a docking study, we propose a model of eriodictyol and JNK binding, in which eriodictyol forms 3 hydrogen bonds with the side chains of Lys55, Met111, and Asp169 in JNK, and in which the hydroxyl groups of the B ring play key roles in binding interactions with JNK. Therefore, eriodictyol may be a potent anti-inflammatory inhibitor of JNK. [BMB Reports 2013; 46(12): 594-599]

Structure and backbone dynamics of vanadate-bound PRL-3: comparison of 15N nuclear magnetic resonance relaxation profiles of free and vanadate-bound PRL-3

Phosphatases of regenerating liver (PRLs) constitute a novel class of small, prenylated phosphatases with oncogenic activity. PRL-3 is particularly important in cancer metastasis and represents a potential therapeutic target. The flexibility of the WPD loop as well as the P-loop of protein tyrosine phosphatases is closely related to their catalytic activity. Using nuclear magnetic resonance spectroscopy, we studied the structure of vanadate-bound PRL-3, which was generated by addition of sodium orthovanadate to PRL-3. The WPD loop of free PRL-3 extended outside of the active site, forming an open conformation, whereas that of vanadate-bound PRL-3 was directed into the active site by a large movement, resulting in a closed conformation. We suggest that vanadate binding induced structural changes in the WPD loop, P-loop, helices α4-α6, and the polybasic region. Compared to free PRL-3, vanadate-bound PRL-3 has a longer α4 helix, where the catalytic R110 residue coordinates with vanadate in the active site. In addition, the hydrophobic cavity formed by helices α4-α6 with a depth of 14-15 Å can accommodate a farnesyl chain at the truncated prenylation motif of PRL-3, i.e., from R169 to M173. Conformational exchange data suggested that the WPD loop moves between open and closed conformations with a closing rate constant k(close) of 7 s(-1). This intrinsic loop flexibility of PRL-3 may be related to their catalytic rate and may play a role in substrate recognition.

Anti-inflammatory activity of rhamnetin and a model of its binding to c-Jun NH2-terminal kinase 1 and p38 MAPK

Rhamnetin (1), a commonly occurring plant O-methylated flavonoid, possesses antioxidant properties. To address the potential therapeutic efficacy of 1, its anti-inflammatory activity and mode of action in mouse macrophage-derived RAW264.7 cells stimulated with lipopolysaccharide (LPS) or interferon (IFN)-γ were investigated. Rhamnetin (1) suppressed mouse tumor necrosis factor (mTNF)-α, mouse macrophage inflammatory protein (mMIP)-1, and mMIP-2 cytokine production in LPS-stimulated macrophages. A nontoxic dose of 1 suppressed nitric oxide production. It was found that the anti-inflammatory effects of 1 are mediated by actions on the p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and cyclooxygenase (COX)-2 pathways in LPS- or IFN-γ-stimulated RAW264.7 cells. It was determined that 1 binds to human JNK1 (9.7 × 10(8) M(-1)) and p38 MAPK (2.31 × 10(7) M(-1)) with good affinity. The binding model showed interactions with the 3'- and 4'-hydroxy groups of the B-ring and the 5-hydroxy group of the A-ring of 1. Further, 1 exerted an anti-inflammatory effect, reducing the levels of pro-inflammatory cytokines and mediators.

Systematic review with meta-analysis: highly selective 5-HT4 agonists (prucalopride, velusetrag or naronapride) in chronic constipation

BACKGROUND

Highly selective 5-HT4 agonists have been suggested for the treatment of chronic constipation (CC).

AIM

To assess the effects of highly selective 5-HT4 agonists (prucalopride, velusetrag or naronapride) on patient-important clinical efficacy outcomes and safety in adults with CC.

METHODS

We searched the medical literature in January 2013 using MEDLINE/Pubmed, Embase, Cochrane Library, and Web of Science/Scopus for randomised, controlled trials of highly selective 5-HT4 agonists in adults with CC, with no minimum duration of therapy (maximum 12 weeks) or date limitations. Data were extracted from intention-to-treat analyses, pooled using a random-effects model, and reported as relative risk (RR), mean differences, or standardised mean differences with 95% confidence intervals (CI).

RESULTS

Main outcomes included stool frequency, Patient-Assessment of Constipation Quality of Life (PAC-QOL), PAC of symptoms (PAC-SYM) and adverse events. Thirteen eligible trials were identified: 11 prucalopride, 1 velusetrag, 1 naronapride. Relative to control, treatment with highly selective 5-HT4 agonists was superior for all outcomes: mean ≥3 spontaneous complete bowel movements (SCBM)/week (RR = 1.85; 95% CI 1.23-2.79); mean ≥1 SCBM over baseline (RR = 1.57; 95% CI 1.19, 2.06); ≥1 point improvement in PAC-QOL and PAC-SYM scores. The only active comparator trial of prucalopride and PEG3350 suggested PEG3350 is more efficacious for some end points. Adverse events were more common with highly selective 5-HT4 agonists, but were generally minor; headache was the most frequent. Most trials studied prucalopride.

CONCLUSION

Demonstration of efficacy on patient-important outcomes and a favourable safety profile support the continued use and development of highly selective 5-HT4 agonists in the treatment of chronic constipation.

Structure-activity relationships of cecropin-like peptides and their interactions with phospholipid membrane

Cecropin A and papiliocin are novel 37-residue cecropin-like antimicrobial peptides isolated from insect. We have confirmed that papiliocin possess high bacterial cell selectivity and has an α-helical structure from Lys³ to Lys²¹ and from Ala²⁵ to Val³⁵, linked by a hinge region. In this study, we demonstrated that both peptides showed high antimicrobial activities against multi-drug resistant Gram negative bacteria as well as fungi. Interactions between these cecropin-like peptides and phospholipid membrane were studied using CD, dye leakage experiments, and NMR experiments, showing that both peptides have strong permeabilizing activities against bacterial cell membranes and fungal membranes as well as Trp² and Phe⁵ at the N-terminal helix play an important role in attracting cecropin-like peptides to the negatively charged bacterial cell membrane. Cecropin-like peptides can be potent peptide antibiotics against multi-drug resistant Gram negative bacteria and fungi. [BMB Reports 2013; 46(5): 282-287]

S-1 plus irinotecan and oxaliplatin for the first-line treatment of patients with metastatic colorectal cancer: a prospective phase II study and pharmacogenetic analysis

BACKGROUND

S-1 is an oral fluoropyrimidine that mimics infusional 5-fluorouracil. The aim of this phase II trial was to explore the clinical efficacy of the triplet regimen TIROX, which consists of S-1, irinotecan and oxaliplatin.

METHODS

Forty-two chemo-naive patients with metastatic colorectal cancer (mCRC) were planned to be enrolled and be treated with irinotecan 150 mg m(-2) followed by oxaliplatin 85 mg m(-2) on day 1 and S-1 80 mg m(-2) per day from day 1 to 14 every 3 weeks. Polymorphisms in the UGT1A1, UGT1A6, UGT1A7 and CYP2A6 genes were analysed.

RESULTS

Between July 2007 and February 2008, 43 patients were enrolled. An objective response was noted in 29 patients (67.4%, 95% confidence interval: 53.4-81.4), of which 2 achieved durable complete responses. The median progression-free survival was 10.0 months and the median overall survival was 19.2 months. Significant grade 3 or 4 adverse events were neutropenia (45.2%), febrile neutropenia (9.5%), diarrhoea (7.1%) and vomiting (9.5%). Increased gastrointestinal toxicities were associated with the presence of UGT1A6*2 or UGT1A7*3 and an improved tumour response was noted in those without variant alleles of CYP2A6 or UGT1A1*60.

CONCLUSION

The combination of S-1, irinotecan and oxaliplatin showed favourable efficacy and tolerability in untreated patients with mCRC.

Simplifying the measurement of gastric accommodation using SPECT

BACKGROUND

Non-invasive single photon emission computed tomography (SPECT) has been validated as a test for postprandial gastric volume accommodation, with volumes measured twice over 30 min and averaged. The purpose of this study is to simplify the SPECT measurement of gastric accommodation.

METHODS

The primary aim of this study was to compare two postprandial gastric volume measurements with data collected retrospectively from 443 patients and healthy volunteers who had undergone SPECT in the last decade. The differences in the two gastric volumes were compared in the entire group and each subgroup, and the correlation between the two measurements and their differences across a wide range of gastric volumes were plotted.

KEY RESULTS

There was a median difference of <2% (P = 0.041) between postprandial scan 1 (757 mL) and scan 2 (743 mL), with significant correlation (rs  = 0.859, P < 0.01) and excellent agreement (SD 60 mL) between the two scans across the entire range of observed postprandial gastric volumes.

CONCLUSIONS & INFERENCES

A single postprandial scan can detect gastric accommodation with the same accuracy as averaging two postprandial scans. These data support simplifying SPECT measurement of postprandial gastric volume with a scan in the first 15 min after a meal.

Interpretation of overall colonic transit in defecation disorders in males and females

BACKGROUND

There is little information regarding gender-specific measurements of colonic transit and anorectal function in patients with defecation disorders (DD). To compare overall colonic transit by gender in DD.

METHODS

In 407 patients with constipation due to DD diagnosed by a single gastroenterologist (1994-2012), DD was characterized by anorectal manometry, balloon expulsion test, and colonic transit by scintigraphy. The primary endpoint was overall colonic transit (geometric center, GC) at 24 h (GC24). Effects of gender in DD on colonic transit, and comparison with transit in 208 healthy controls were assessed by Mann-Whitney rank sum test. Secondary endpoints were maximum anal resting (ARP) and squeeze (ASP) pressures. We also tested association of the physiological endpoints among DD females by pregnancy history and among DD patients by colectomy history.

KEY RESULTS

The DD patients were 67 males (M) and 340 females (F). Significant differences by gender in DD patients were observed in GC24 (median: M: 2.2; F: 1.8; P = 0.01), ARP (median: M: 87.8 mmHg; F: 82.4 mmHg; P = 0.04), and ASP (median: M: 182.4 mmHg; F: 128.7 mmHg; P < 0.001). GC24 was slower in DD compared with same-gender healthy controls. GC24 did not differ among DD females by pregnancy history. Anorectal functions and upper GI transit did not differ among DD patients by colectomy history.

CONCLUSIONS & INFERENCES

Patients with DD have slower colonic transit compared with gender-matched controls. Among DD patients, males have higher ARP and ASP, and females have slower colonic transit. Although the clinical significance of these differences may be unclear, findings suggest that interpretation of these tests in suspected DD should be based on same-gender control data.

Performance characteristics of scintigraphic measurement of gastric emptying of solids in healthy participants

BACKGROUND

Gastric emptying (GE) is measured in pharmacodynamic and diagnostic studies. Our aim was to assess inter- and intra-subject coefficients of variation (COV) of scintigraphic GE measurements in healthy subjects, and associations of GE with gender and body mass index (BMI).

METHODS

Data from participants with scintigraphic measurements of gastric emptying of solids were analyzed. Primary endpoints were gastric emptying T(1/2) (GE T(1/2) ) and GE at 1, 2, 3, and 4 h.

KEY RESULTS

The patient cohort consisted of 105 males and 214 females; at least two studies were performed in 47 subjects [16 males (M), 32 females (F)]. Inter-subject COV (COV(inter) ) for GE T(1/2) were similar in M and F: overall 24.5% (M 26.0%, F 22.5%); COV are predictably lowest for GE at 4 h (COV(inter) 9.6%). COV(intra) for T(1/2) and GE at 4 h were overall 23.8% and 12.6%, and were similar to COV(inter) values. Gender (but not age or BMI) was significantly associated with GE T1/2 [P < 0.001, F 127.6 ± 28.7 (SD) min; M 109.9 ± 28.6 min] and with GE at 1 h and 2 h. Repeat GE T(1/2) values in 47 participants were significantly correlated (r = 0.459, P < 0.001) with median difference of -6 min (mean -1.6, range -56 to 72 min). Bland-Altman plots showed Δ GE T(1/2) similarly distributed across mean GE T(1/2) 100-155 min, and across studies conducted 90-600 days apart.

CONCLUSIONS & INFERENCES

Inter-subject variations in scintigraphic GE results are only slightly higher than the intra-subject measurements, which are also reproducible over time in healthy volunteers. Gender, but not BMI, is significantly associated with GE results.

Insight into the antimicrobial activities of coprisin isolated from the dung beetle, Copris tripartitus, revealed by structure-activity relationships

The novel 43-residue, insect defensin-like peptide coprisin, isolated from the dung beetle, Copris tripartitus, is a potent antibiotic with bacterial cell selectivity, exhibiting antimicrobial activities against Gram-positive and Gram-negative bacteria without exerting hemolytic activity against human erythrocytes. Tests against Staphylococcus aureus using fluorescent dye leakage and depolarization measurements showed that coprisin targets the bacterial cell membrane. To understand structure-activity relationships, we determined the three-dimensional structure of coprisin in aqueous solution by nuclear magnetic resonance spectroscopy, which showed that coprisin has an amphipathic α-helical structure from Ala(19) to Arg(28), and β-sheets from Gly(31) to Gln(35) and Val(38) to Arg(42). Coprisin has electropositive regions formed by Arg(28), Lys(29), Lys(30), and Arg(42) and ITC results proved that coprisin and LPS have electrostatically driven interactions. Using measurements of nitric oxide release and inflammatory cytokine production, we provide the first verification of the anti-inflammatory activity and associated mechanism of an insect defensin, demonstrating that the anti-inflammatory actions of the defensin-like peptide, coprisin, are initiated by suppressing the binding of LPS to toll-like receptor 4, and subsequently inhibiting the phosphorylation of p38 mitogen-activated protein kinase and nuclear translocation of NF-kB. In conclusion, we have demonstrated that an amphipathic helix and an electropositive surface in coprisin may play important roles in its effective interaction with bacterial cell membranes and, ultimately, in its high antibacterial activity and potent anti-inflammatory activity. In addition to elucidating the antimicrobial action of coprisin, this work may provide insight into the mechanism of action of insect defense systems.

A randomised, placebo-controlled trial comparing the effects of tapentadol and oxycodone on gastrointestinal and colonic transit in healthy humans

BACKGROUND

Tapentadol is a mu-opioid receptor agonist and norepinephrine reuptake inhibitor. In clinical trials, tapentadol provided somatic pain relief comparable to mu-opioids such as oxycodone, with significantly less gastrointestinal adverse effects. The acute effects of tapentadol on gastrointestinal and colonic transit are unclear.

AIM

To compare acute effects of oral tapentadol and oxycodone on gastric, small bowel and colonic transit of solids in 38 healthy human subjects.

METHODS

In a randomised, parallel-group, double-blind, placebo-controlled study of the effects of identical-appearing tapentadol immediate release (IR), 75 mg t.d.s., or oxycodone IR, 5 mg t.d.s., for 48 h, we measured gastric (GE), small bowel (SBT measured as colonic filling at 6 h) and colonic transit by validated scintigraphy. Drug was commenced on the evening before the start of the transit test. The primary endpoints were overall colonic transit (geometric centre, GC) at 24 h and GE half-time (t1/2 ). ancova of transit data included gender or BMI as covariates. Adverse effects were summarised.

RESULTS

At the doses tested, oxycodone and tapentadol significantly delayed GE t1/2 and SBT, but not overall colonic transit, compared to placebo. Transit profiles in all regions were not significantly different between oxycodone and tapentadol at the doses tested. Both oxycodone and tapentadol were associated with nausea and central effects attributable to central opiate effects.

CONCLUSIONS

Tapentadol significantly delayed gastric emptying t1/2 and small bowel transit, similar to oxycodone. These data suggest that acute administration of tapentadol may not have significant advantages over standard mu-opioids, in terms of the potential to avoid upper gastrointestinal motor dysfunction.

Body mass, tobacco smoking, alcohol drinking and risk of cancer of the small intestine--a pooled analysis of over 500,000 subjects in the Asia Cohort Consortium

BACKGROUND

The evidence for a role of tobacco smoking, alcohol drinking, and body mass index (BMI) in the etiology of small intestine cancer is based mainly on case-control studies from Europe and United States.

SUBJECTS AND METHODS

We harmonized the data across 12 cohort studies from mainland China, Japan, Korea, Singapore, and Taiwan, comprising over 500,000 subjects followed for an average of 10.6 years. We calculated hazard ratios (HRs) for BMI and (only among men) tobacco smoking and alcohol drinking.

RESULTS

A total of 134 incident cases were observed (49 adenocarcinoma, 11 carcinoid, 46 other histologic types, and 28 of unknown histology). There was a statistically non-significant trend toward increased HR in subjects with high BMI [HR for BMI>27.5 kg/m2, compared with 22.6-25.0, 1.50; 95% confidence interval (CI) 0.76-2.96]. No association was suggested for tobacco smoking; men drinking>400 g of ethanol per week had an HR of 1.57 (95% CI 0.66-3.70), compared with abstainers.

CONCLUSIONS

Our study supports the hypothesis that elevated BMI may be a risk factor for small intestine cancer. An etiologic role of alcohol drinking was suggested. Our results reinforce the existing evidence that the epidemiology of small intestine cancer resembles that of colorectal cancer.

Dietary patterns and the prevalence of metabolic syndrome in Korean women

BACKGROUND AND AIMS

The role of dietary patterns in metabolic syndrome has not been adequately investigated in Asian women. We aimed to identify dietary patterns and to evaluate the cross-sectional relationship between dietary patterns and the prevalence of metabolic syndrome in Korean women.

METHODS AND RESULTS

In a cross-sectional study of 4984 women aged 30-79 years, dietary patterns were derived from 16 food groups using factor analysis. Metabolic syndrome was defined based on the Adult Treatment Panel III of the National Cholesterol Education Program (ATPIII NCEP) criteria as having three or more risk factors using a modified obesity index. Logistic regression was used to estimate the association between dietary pattern and the prevalence of metabolic syndrome. Three dietary patterns (Western, healthy and traditional) were identified. Higher consumption of the healthy pattern was inversely associated with metabolic syndrome (OR [95% CI] for highest vs. lowest quartile: 0.58 [0.50-0.91]; P for trend = 0.012) and most components of metabolic syndrome. In a stratified analysis by menopausal status, the inverse association of the healthy dietary pattern and metabolic syndrome was statistically significant only among postmenopausal women (OR [95% CI] for highest vs. lowest quartile: 0.60 [0.40-0.86]; P for trend = 0.004). The Western and traditional patterns showed no association with metabolic syndrome, but were related to some individual risk factors for metabolic syndrome.

CONCLUSIONS

These results suggest that the healthy dietary pattern is associated with a reduced risk for metabolic syndrome in Korean women, particularly in postmenopausal women.

Combined effect of socioeconomic status, viral hepatitis, and lifestyles on hepatocelluar carcinoma risk in Korea

Background:

The independent and combined effects of socioeconomic status (SES), viral hepatitis, and other lifestyle factors on hepatocellular carcinoma (HCC) risk have not been investigated among Koreans.

Methods:

From the National Cancer Center Hospital, 207 HCC cases and 828 age- and gender-matched controls aged 30 years or older were recruited. Socio-demographic and behavioural risk factors were ascertained through personal interview, and infection with hepatitis B and C viruses was determined by their serologic markers. Multivariate logistic regression and synergy index methods were applied for statistical analysis.

Results:

HB surface antigen (HbsAg) and anti-HCV-positive rates were 149.3 and 185.1 times higher in cases than controls, respectively. Lifetime alcohol consumption (odds ratio: 2.96, 95% CI: 1.29–6.79), cigarette smoking (OR: 3.53, 95% CI: 1.31–9.52), and family income (OR: 17.07, 95% CI: 4.27–68.25) were independently associated with the risk of HCC in subjects with or without viral hepatitis. Synergistic interaction on HCC risk was observed between low income and HBsAg positivity (SI: 3.12, 95% CI: 1.51–6.47) and between low income and heavy alcohol intake (SI: 2.93, 95% CI: 1.24–6.89).

Conclusion:

The inverse association with SES suggests SES as an independent and synergistic predictor of HCC. Heavy alcohol intake also showed a combined effect with low SES on HCC risk.