Novel case of combination antibiotic therapy for treatment of a complicated polymicrobial urinary tract infection with one organism harboring a metallo-β-lactamase (MBL) in a pregnant patient

Carbapenem resistance due to metallo-beta-lactamases (MBLs) is a global phenomenon and an important challenge for antibiotic therapy (Boyd et al., 2020 [1]). While previous reports have demonstrated both in vitro and in vivo synergy using the combination of ceftazidime-avibactam and aztreonam against Stenotrophomonas maltophilia, an MBL-harboring organism, this treatment strategy has not been reported during pregnancy (Mojic et al., 2017 [2], [3], Mojica et al., 2016 [4], Alexander et al., 2020 [5]). We describe a 33-year-old pregnant female with polymicrobial, bilateral pyelonephritis caused by Stenotrophomonas maltophilia and other gram-negative bacteria. The organisms were eradicated with the combination of ceftazidime-avibactam and aztreonam followed by successful delivery with no observed adverse effects in either mother or child post-partum.

A novel approach to study multi-domain motions in JAK1's activation mechanism based on energy landscape

The family of Janus Kinases (JAKs) associated with the JAK-signal transducers and activators of transcription signaling pathway plays a vital role in the regulation of various cellular processes. The conformational change of JAKs is the fundamental steps for activation, affecting multiple intracellular signaling pathways. However, the transitional process from inactive to active kinase is still a mystery. This study is aimed at investigating the electrostatic properties and transitional states of JAK1 to a fully activation to a catalytically active enzyme. To achieve this goal, structures of the inhibited/activated full-length JAK1 were modelled and the energies of JAK1 with Tyrosine Kinase (TK) domain at different positions were calculated, and Dijkstra's method was applied to find the energetically smoothest path. Through a comparison of the energetically smoothest paths of kinase inactivating P733L and S703I mutations, an evaluation of the reasons why these mutations lead to negative or positive regulation of JAK1 are provided. Our energy analysis suggests that activation of JAK1 is thermodynamically spontaneous, with the inhibition resulting from an energy barrier at the initial steps of activation, specifically the release of the TK domain from the inhibited Four-point-one, Ezrin, Radixin, Moesin-PK cavity. Overall, this work provides insights into the potential pathway for TK translocation and the activation mechanism of JAK1.

Structural Analysis of Janus Tyrosine Kinase Variants in Hematological Malignancies: Implications for Drug Development and Opportunities for Novel Therapeutic Strategies

Janus tyrosine kinase (JAK) variants are known drivers for hematological disorders. With the full-length structure of mouse JAK1 being recently resolved, new observations on the localization of variants within closed, open, and dimerized JAK structures are possible. Full-length homology models of human wild-type JAK family members were developed using the Glassman et al. reported mouse JAK1 containing the V658F structure as a template. Many mutational sites related to proliferative hematological disorders reside in the JH2 pseudokinase domains facing the region important in dimerization of JAKs in both closed and open states. More than half of all JAK gain of function (GoF) variants are changes in polarity, while only 1.2% are associated with a change in charge. Within a JAK1-JAK3 homodimer model, IFNLR1 (PDB ID7T6F) and the IL-2 common gamma chain subunit (IL2Rγc) were aligned with the respective dimer implementing SWISS-MODEL coupled with ChimeraX. JAK3 variants were observed to encircle the catalytic site of the kinase domain, while mutations in the pseudokinase domain align along the JAK-JAK dimerization axis. FERM domains of JAK1 and JAK3 are identified as a hot spot for hematologic malignancies. Herein, we propose new allosteric surfaces for targeting hyperactive JAK dimers.

JAK3 Y841 Autophosphorylation Is Critical for STAT5B Activation, Kinase Domain Stability and Dimer Formation

Janus tyrosine kinase 3 (JAK3) is primarily expressed in immune cells and is needed for signaling by the common gamma chain (γc) family of cytokines. Abnormal JAK3 signal transduction can manifest as hematological disorders, e.g., leukemia, severe combined immunodeficiency (SCID) and autoimmune disease states. While regulatory JAK3 phosphosites have been well studied, here a functional proteomics approach coupling a JAK3 autokinase assay to mass spectrometry revealed ten previously unreported autophosphorylation sites (Y105, Y190, Y238, Y399, Y633, Y637, Y738, Y762, Y824, and Y841). Of interest, Y841 was determined to be evolutionarily conserved across multiple species and JAK family members, suggesting a broader role for this residue. Phospho-substitution mutants confirmed that Y841 is also required for STAT5 tyrosine phosphorylation. The homologous JAK1 residue Y894 elicited a similar response to mutagenesis, indicating the shared importance for this site in JAK family members. Phospho-specific Y841-JAK3 antibodies recognized activated kinase from various T-cell lines and transforming JAK3 mutants. Computational biophysics analysis linked Y841 phosphorylation to enhanced JAK3 JH1 domain stability across pH environments, as well as to facilitated complementary electrostatic JH1 dimer formation. Interestingly, Y841 is not limited to tyrosine kinases, suggesting it represents a conserved ubiquitous enzymatic function that may hold therapeutic potential across multiple kinase families.

Phosphorylation of Tyrosine 841 Plays a Significant Role in JAK3 Activation

Janus Kinase 3 (JAK3) plays a key role in the development, proliferation, and differentiation of various immune cells. It regulates gene expression by phosphorylation of Signal Transducers and Activators of Transcriptions (STATs) via the JAK/STAT pathway. Recently, we found a new JAK3 phosphorylation site, tyrosine 841 (Y841). The results showed that pY841 helps the kinase domain flip around the pseudo kinase domain, which may cause JAK3 conformational changes. It also reduces the size of the cleft between the N-lobe and the C-lobe of the JAK3 kinase domain. However, pY841 was found to enlarge the cleft when ATP/ADP was bound to the kinase. The increase in the cleft size suggested that pY841 enhanced the elasticity of the kinase domain. For unphosphorylated JAK3 (JAK3-Y841), the binding forces between the kinase domain and ATP or ADP were similar. After phosphorylation of Y841, JAK3-pY841 exhibited more salt bridges and hydrogen bonds between ATP and the kinase than between ADP and the kinase. Consequently, the electrostatic binding force between ATP and the kinase was higher than that between ADP and the kinase. The result was that compared to ADP, ATP was more attractive to JAK3 when Y841 was phosphorylated. Therefore, JAK3-pY841 tended to bind ATP rather than ADP. This work provides new insights into the role of phosphorylation in kinase activation and ATP hydrolysis and sheds light on the importance of understanding the molecular mechanisms that regulate the kinase function.

JAK1 Pseudokinase V666G Mutant Dominantly Impairs JAK3 Phosphorylation and IL-2 Signaling

Overactive Janus kinases (JAKs) are known to drive leukemia, making them well-suited targets for treatment. We sought to identify new JAK-activating mutations and instead found a JAK1-inactivating pseudokinase mutation, V666G. In contrast to other pseudokinase mutations that canonically lead to an active kinase, the JAK1 V666G mutation led to under-activation seen by reduced phosphorylation. To understand the functional role of JAK1 V666G in modifying kinase activity we investigated its influence on other JAK kinases and within the Interleukin-2 pathway. JAK1 V666G not only inhibited its own activity, but its presence could inhibit other JAK kinases. These findings provide new insights into the potential of JAK1 pseudokinase to modulate its own activity, as well as of other JAK kinases. Thus, the features of the JAK1 V666 region in modifying JAK kinases can be exploited to allosterically inhibit overactive JAKs.

Rapid Shift from SARS-CoV-2 Delta to Omicron Sub-Variants within a Dynamic Southern U.S. Borderplex

COVID-19, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), remains an ongoing global health challenge. This study analyzed 3641 SARS-CoV-2 positive samples from the El Paso, Texas, community and hospitalized patients over 48 weeks from Fall 2021 to Summer 2022. The binational community along the U.S. southern border was predominantly SARS-CoV-2 Delta variant (B.1.617.2) positive for a 5-week period from September 2021 to January 2022 and quickly transitioned to the Omicron variant (B.1.1.529), which was first detected at the end of December 2021. Omicron replaced Delta as the predominant detectable variant in the community and was associated with a sharp increase in COVID-19 positivity rate, related hospitalizations, and newly reported cases. In this study, Omicron BA.1, BA.4, and BA.5 variants were overwhelmingly associated with S-gene dropout by qRT-PCR analysis unlike the Delta and Omicron BA.2 variants. The study reveals that a dominant variant, like Delta, can be rapidly replaced by a more transmissible variant, like Omicron, within a dynamic metropolitan border city, necessitating enhanced monitoring, readiness, and response from public health officials and healthcare workers.

Low Dose Radiotherapy in the Management of COVID-19 Pneumonia (LOWRAD-Cov19): Final Results

Purpose/Objective(s)

To evaluate the results of LD-RT to lungs in the management of patients with COVID-19 pneumonia.

Materials/Methods

We conducted a prospective phase I-II trial enrolling COVID-19 patients ≥50 years-old, with bilateral lung involvement at imaging study and oxygen requirement. Patients received 1 Gy to whole lungs in a single fraction. Primary outcome was radiological response assessed as severity and extension scores at days +3 and +7. Secondary outcomes were toxicity (CTCAE v5.0), days of hospitalization, changes in inflammatory blood parameters (ferritin, lymphocytes, C-reactive protein, d-dimer and LDH) and SatO2/ FiO2 index (SAFI), at day +3 and +7. Descriptive analyses were summarized as means with standard deviation (SD) and/or medians with interquartile ranges (IQR). A Wilcoxon sign rank test for paired data was used to assess the CT scores and Chi Square was used to assess for comparison of categorical variables.

Results

Forty-one patients were included. Median age was 71 (IQR 60-84). Eighteen patients (47%) previously received any antiCOVID treatment (tocilizumab, lopinavir/ritonavir, remdesivir) and thirty-two patients (84%) received steroids during LD-RT. Extension score improved significantly (p=0.02) on day +7 and SAFI on day +3 and + 7 (p<0.01). Median SAFI on day 0 was 147 (IQR 118-264), 230 (IQR 120-343) on day +3 and 293 (IQR 121-353) on day +7. Significant decrease was found in C-reactive protein on day +7 (p=0.02) and in lymphocytes counts on day +3 and +7 (p=0.02). Median number of days in hospital after RT was 11 (range 4-78). With a median follow-up of 60 days after LD-RT, 26 (63%) patients were discharged, 11 (27%) died because of COVID respiratory failure and 4 (10%) died of other causes.

Conclusion

LD-RT is a feasible and well-tolerated treatment that may lead to rapid clinical improvement. Large randomized trials should be done to establish the efficacy of LD-RT to treat COVID-19 pneumonia.

POS0707 POTENTIAL USE OF BELIMUMAB IN LUPUS PATIENTS FROM ARGENTINE COHORT ACCORDING DISEASE ACTIVITY STATE

Background

The goal of targeted treatment in patients with Systemic Lupus Erythematosus (SLE) is to achieve clinical remission or low disease activity, with the best quality of life, low damage rates and better survival 1-4. RELESSAR is a multicenter, cross-sectional study registry of ≥18 years SLE (ACR 97) patients 5.

Objectives

To describe demographic, clinical characteristics and treatments in SLE patients according to disease activity state. To evaluate the proportion of SLE and refractory SLE patients that are potentially candidates for Belimumab treatment (Active SLE despite standard treatment including increased acDNA autoantibodies and low complement).

Methods

We evaluated demographic and clinical data, treatments, score of damage (SLICC), activity (SLEDAI) and comorbidity (Charlson), hospital admissions and severe infections. The patients were compared according to disease activity: remission (SLEDAI = 0 and without corticosteroids), low disease activity (LDA, SLEDAI> 0 and ≤4 and without corticosteroids) and non-optimal control (SLEDAI> 4 and any dose of corticosteroids). Refractory SLE was defined according to Rituximab (RTX) use, non-response to cyclophosphamide or two or more immunosuppressant or splenectomized patients. Potential use of Belimumab according approved prescription in Argentina was analyzed.

Results

Overall, 1277 patients were analyzed: 299 (23.4%) were in remission, 162 (12.7%) in LDA and 816 (63.9%) with non-optimal control of the disease.

Patients in non-optimal control group were younger, less frequently female and they showed less time of disease and lower socioeconomic status (p < 0.001). They were also more prevalent mestizos (p= 0.004), had higher SLEDAI and SLICC indexes (p <0.001) and higher use of immunosuppressant therapy (p <0.001). There was no difference regarding biologic treatment (RTX p= 0.547 and Belimumab p= 0.08). This group had higher proportion of hospital admissions and severe infections (p<0.001, respectively).

Two hundred and one SLE patients fulfilled the use of Belimumab prescription criteria but only 45/201 patients (22,3%) received it in the last visit. Malar rash was the only clinical variable associated with the use of Belimumab (72.7% vs 29.8% p= 0.005).

Seventy-six patients classified as refractory SLE (15.7%) and 56/76 (75.7%) never received Belimumab. Patients on Belimumab therapy were associated to treatment with lower doses of corticoids (p= 0.018) and lower rate of hospital admission caused by SLE flare (p= 0.027).

Conclusion

A high percentage of patients had uncontrolled disease upon entry into the registry and were potential candidates for treatment with Belimumab. The patients who received biologic treatment showed the benefit of requiring fewer doses of corticosteroids and having a lower rate of hospitalizations.

References

[1]Mok CC. Treat-to-target in systemic lupus erythematosus: Are we there yet? Expert Rev Clin Pharmacol. 2016;9(5).

[2]Morand EF, Mosca M. Treat to target, remission and low disease activity in SLE. Vol. 31, Best Practice and Research: Clinical Rheumatology. 2017.

[3]Golder V, Tsang-A-Sjoe MWP. Treatment targets in SLE: Remission and low disease activity state. Rheumatol (United Kingdom). 2020;59.

[4]Ruiz-Irastorza G, Bertsias G. Treating systemic lupus erythematosus in the 21st century: new drugs and new perspectives on old drugs. Vol. 59, Rheumatology (United Kingdom). 2021.

[5]Hochberg MC. Updating the American College of Rheumatology revised criteria for the classification of systemic lupus erythematosus. Arthritis Rheum [Internet]. 1997;40(9):1725. Available from: http://www.ncbi.nlm.nih.gov/pubmed/9324032

Disclosure of Interests

Rosana Quintana: None declared, Lucila Garcia: None declared, Paula Alba: None declared, Susana Roverano: None declared, Analia Alvarez: None declared, Cesar Graf: None declared, Cecilia Pisoni: None declared, Alberto Spindler: None declared, Catalina Gomez: None declared, Heber Matias Figueredo: None declared, Silvia Papasidero: None declared, Raul Horacio Paniego: None declared, Maria DeLaVega: None declared, Emma Estela Civit De Garignani: None declared, Luciana Gonzalez Lucero: None declared, Victoria Martire: None declared, Rodrigo Águila Maldonado: None declared, Sergio Gordon: None declared, Carla Gobbi: None declared, Romina Nieto: None declared, Gretel Rausch: None declared, Vanina Góngora: None declared, Maria Agustina D´Amico: None declared, Diana Dubinsky: None declared, Alberto Omar Orden: None declared, Johana Zacariaz: None declared, Julia Romero: None declared, Mariana Alejandra Pera: None declared, Oscar Rillo: None declared, Roberto Baez: None declared, Valeria Arturi: None declared, Andrea Gonzalez: None declared, Florencia Vivero: None declared, Marcela Schmid: None declared, Victor Caputo: None declared, Maria Silvia Larroude: None declared, Graciela Gomez: None declared, Graciela Rodriguez: None declared, Josefina Marin: None declared, Maria Victoria Collado: None declared, Marisa Jorfen: None declared, Zaida Bedran: None declared, Judith Sarano: None declared, David Zelaya: None declared, MONICA SACNUN: None declared, Pablo Finucci: None declared, Romina Rojas Tessel: None declared, Maria Emilia Sattler: None declared, MAXIMILIANO MACHADO ESCOBAR: None declared, Pablo Astesana: None declared, Ursula Vanesa Paris: None declared, Alberto Allievi: None declared, Juan Manuel Vandale: None declared, Bernardo Pons-Estel: None declared, Guillermo Pons-Estel: None declared, Mercedes García Grant/research support from: GSK grant

POS0673 ENDOTHELIAL INFLAMMATION IN RHEUMATOID ARTHRITIS PATIENTS TREATED WITH TOFACITINIB

Background

Systemic inflammation in rheumatoid arthritis (RA) seems to accelerate atherosclerosis process and increased cardiovascular (CV) events. An adequate joint inflammation control is correlated with endothelial inflammation (EI) improvement. 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG PET/CT) has been shown as a non-invasive, sensitive, and specific tool to show EI. Maximum standardized uptake value (SUV(max)) greater than 1,6 has been correlated with vascular and joint inflammation. Tofacitinib is a Jak inhibitor (JaKi) approved for RA that improves activity and function. The aim of this study is to evaluate the EI outcome by FDG-PET in RA patients treated with tofacitinib.

Objectives

To assess the EI by FDG-PET/CT in RA patients at baseline and after 12 weeks of tofacitinib treatment initiation.

To correlate the vascular findings with disease activity, lipid profile and carotid atherosclerosis by echo Doppler.

Methods

Prospective, observational study. Inclusion criteria: RA (ACR 2010) patients >18 years old, with high activity score (DAS 28 >3,2) and with biologics or synthetic Dmards requirement by Treat to Target strategy and who tofacitinib was prescribed. Exclusion Criteria: Biologics or Jaki previous use or major CV history known.

A baseline Visit evaluating disease activity (DAS 28 and CDAI), functional status by Health Assessment Questionary (HAQ), CV and smoking history, treatments and lipid lab assessment was performed. EI was measured by PET-FDG/CT, showing the SUVmax and target-to-background ratio (TBR) in: right primitive carotid, left primitive carotid, ascendent aorta, descendent aorta and abdominal aorta. Carotid echo Doppler for showing plaque presence was done. During baseline visit tofacitinib was started. After 12 weeks the initial parameters were re-evaluated.

Results

Consecutively, 30 patients were included. Mean age 57 yo (21-79). Female 70%. Mean disease duration 8,3 years (1-40), mean Body mass index (BMI) 24,5. Clinical history: Hypertension 27%, smoking 6,6%, methotrexate treatment 46,6%, methotrexate plus leflunomide 50%, corticosteroids 7,6% (mean dosis 7,6 mg/day).

Mean values of DAS 28, CDAI and HAQ were 5.21, 26,6 y 1,56 in baseline and 3,04, 8,80 y 1,09 in the final visit respectively (p:< 0,001 in all comparations) showing statistical significance activity improvement. Echo doppler showed Carotid plaque in 40% of patients without change between visits. Mean cholesterol levels were 188,5 y 207,53 mg/dl in baseline and final visit respectively (p: 0,0039), showing statistical significance. Endothelial uptake by PET-FDG in the 5 areas measured, considering baseline and final visit was: Right Primitive Carotid: SUV Max 2,03 and 1,93 (p: 0,32) and TRB Max 0,94 and 0,85 (p:1,0); Left Primitive Carotid Suv Max 2,07 and 1,94 (p:1,0) and TRB Max 0,92 and 0,90 (p:0,57); Ascendent Aorta SUV Max 2,63 and 2,57 (p:1,0) and TRB Max 1,18 and 1,15 (p:1,0); Descendent Aorta SUV Max 2,77 and 2,57 (p:0,26) and TRB Max 1,27 and 1,17 (p:0,26) and Abdominal Aorta SUV Max 2,59 and 2,43 (p:0,85) and TRB Max 1,15 y 1,11 (p:0,32). None of the endothelial uptake comparisons showed a significant difference between baseline and final visit after 12 weeks.

Conclusion

This work shows that, despite the significant improvement in joint activity and function values, there was no modification in EI measured by FDG-PET during tofacitinib treatment along 12 weeks. It is noteworthy that all patients initially presented high inflammatory endothelial uptake values, which reinforces the hypothesis of vascular compromise associated with active joint disease. Studies with more observation time and evaluating the role of different treatments related to endothelium will be of clinical utility in the future.

References

[1]Rheumatology (Oxford). 2016 Oct;55(10):1777-85.

[2]Metabolism. 2017 Feb;67:72-79.

[3]Arthritis Res Ther. 2016 May 21;18(1):115.

Acknowledgements

Pfizer´s unrestricted grant

Disclosure of Interests

None declared

Physico-chemical characteristics and oxidative stability of oils from different Peruvian castor bean ecotypes

The aim of this research was to assess the physico-chemical properties and shelf-life of oils press-extracted at two temperatures (60 °C and 80 °C) from five Peruvian castor bean ecotypes. A wide variation for all traits was observed. Low acidity index, low peroxide index and absence of p-anisidine were recorded. The total tocopherol contents ranged from 798 to 1040 mg/kg. A higher antioxidant capacity was detected in methanolic extracts than in hexane extract. From the Rancimat performed at 150-170 °C, the predicted shelf-life at 25 °C ranged from 0.15 to 8.93 years; the higher extraction temperature led to a longer shelf-life, probably because of enzyme inactivation.

Quadruple and Truncated MEK3 Mutants Identified from Acute Lymphoblastic Leukemia Promote Degradation and Enhance Proliferation

Compared to other ethnicities, Hispanic children incur the highest rates of leukemia, and most cases are diagnosed as Acute Lymphoblastic Leukemia (ALL). Despite improved treatment and survival for ALL, disproportionate health outcomes in Hispanics persist. Thus, it is essential to identify oncogenic mutations within this demographic to aid in the development of new strategies to diagnose and treat ALL. Using whole-exome sequencing, five single nucleotide polymorphisms within mitogen-activated protein kinase 3 (MAP2K3) were identified in an ALL cancer patient library from the U.S./Mexico border. MAP2K3 R26T and P11T are located near the substrate-binding site, while R65L and R67W localized to the kinase domain. Truncated-MAP2K3 mutant Q73* was also identified. Transfection in HEK293 cells showed that the quadruple-MEK3 mutant (4M-MEK3) impacted protein stability, inducing degradation and reducing expression. The expression of 4M-MEK3 could be rescued by cysteine/serine protease inhibition, and proteasomal degradation of truncated-MEK3 occurred in a ubiquitin-independent manner. MEK3 mutants displayed reduced auto-phosphorylation and enzymatic activity, as seen by decreases in p38 phosphorylation. Furthermore, uncoupling of the MEK3/p38 signaling pathway resulted in less suppressive activity on HEK293 cell viability. Thus, disruption of MEK3 activation may promote proliferative signals in ALL. These findings suggest that MEK3 represents a potential therapeutic target for treating ALL.

Phosphorylation of CrkL S114 induced by common gamma chain cytokines and T-cell receptor signal transduction

T-cell activation and cellular expansion by common gamma chain cytokines such as Interleukin-2 is necessary for adaptive immunity. However, when unregulated these same pathways promote pathologies ranging from autoimmune disorders to cancer. While the functional role of Interleukin-2 and downstream effector molecules is relatively clear, the repertoire of phosphoregulatory proteins downstream of this pathway is incomplete. To identify phosphoproteins downstream of common gamma chain receptor, YT cells were radiolabeled with [³²P]-orthophosphate and stimulated with Interleukin-2. Subsequently, tyrosine phosphorylated proteins were immunopurified and subjected to tandem mass spectrometry-leading to the identification of CrkL. Phosphoamino acid analysis revealed concurrent serine phosphorylation of CrkL and was later identified as S114 by mass spectrometry analysis. S114 was inducible through stimulation with Interleukin-2 or T-cell receptor stimulation. Polyclonal antibodies were generated against CrkL phospho-S114, and used to show its inducibility by multiple stimuli. These findings confirm CrkL as an Interleukin-2 responsive protein that becomes phosphorylated at S114 by a kinase/s downstream of PI3K and MEK/ERK signaling.

The Many Faces of JAKs and STATs Within the COVID-19 Storm

The positive-sense single stranded RNA virus, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), resulted in a global pandemic with horrendous health and economic consequences not seen in a century. At a finer scale, immunologically, many of these devastating effects by SARS-CoV-2 can be traced to a "cytokine storm" resulting in the simultaneous activation of Janus Kinases (JAKs) and Signal Transducers and Activators of Transcription (STAT) proteins downstream of the many cytokine receptor families triggered by elevated cytokines found in Coronavirus Disease 2019 (COVID-19). In this report, cytokines found in the storm are discussed in relation to the JAK-STAT pathway in response to SARS-CoV-2 and the lessons learned from RNA viruses and previous Coronaviruses (CoVs). Therapeutic strategies to counteract the SARS-CoV-2 mediated storm are discussed with an emphasis on cell signaling and JAK inhibition.

The Genomic Landscape of a Restricted ALL Cohort from Patients Residing on the U.S./Mexico Border

Next-generation sequencing (NGS) has identified unique biomarkers yielding new strategies in precision medicine for the treatment of Acute lymphoblastic leukemia (ALL). Hispanics show marked health disparities in ALL, often absent in clinical trials or cancer research. Thus, it is unknown whether Hispanics would benefit equally from curated data currently guiding precision oncology. Using whole-exome sequencing, nine ALL patients were screened for mutations within genes known to possess diagnostic, prognostic and therapeutic value. Genes mutated in Hispanic ALL patients from the borderland were mined for potentially pathogenic variants within clinically relevant genes. KRAS G12A was detected in this unique cohort and its frequency in Hispanics from the TARGET-ALL Phase II database was three-fold greater than that of non-Hispanics. STAT5B N642H was also detected with low frequency in Hispanic and non-Hispanic individuals within TARGET. Its detection within this small cohort may reflect a common event in this demographic. Such variants occurring in the MAPK and JAK/STAT pathways may be contributing to Hispanic health disparities in ALL. Notable variants in ROS1, WT1, and NOTCH2 were observed in the ALL borderland cohort, with NOTCH2 C19W occurring most frequently. Further investigations on the pathogenicity of these variants are needed to assess their relevance in ALL.

Deficits across multiple behavioral domains align with susceptibility to stress in 129S1/SvImJ mice

Acute physical or psychological stress can elicit adaptive behaviors that allow an organism maintain homeostasis. However, intense and/or prolonged stressors often have the opposite effect, resulting in maladaptive behaviors and curbing goal-directed action; in the extreme, this may contribute to the development of psychiatric conditions like generalized anxiety disorder, major depressive disorder, or post-traumatic stress disorder. While treatment of these disorders generally focuses on reducing reactivity to potentially threatening stimuli, there are in fact impairments across multiple domains including valence, arousal, and cognition. Here, we use the genetically stress-susceptible 129S1 mouse strain to explore the effects of stress across multiple domains. We find that 129S1 mice exhibit a potentiated neuroendocrine response across many environments and paradigms, and that this is associated with reduced exploration, neophobia, decreased novelty- and reward-seeking, and spatial learning and memory impairments. Taken together, our results suggest that the 129S1 strain may provide a useful model for elucidating mechanisms underlying myriad aspects of stress-linked psychiatric disorders as well as potential treatments that may ameliorate symptoms.

Installing oncofertility programs for common cancers in limited resource settings (Repro-Can-OPEN Study): An extrapolation during the global crisis of Coronavirus (COVID-19) pandemic

PURPOSE

The state of limited resource settings that Coronavirus (COVID-19) pandemic has created globally should be taken seriously into account especially in healthcare sector. In oncofertility, patients should receive their fertility preservation treatments urgently even in limited resource settings before initiation of anticancer therapy. Therefore, it is very crucial to learn more about oncofertility practice in limited resource settings such as in developing countries that suffer often from shortage of healthcare services provided to young patients with cancer.

METHODS

As an extrapolation during the global crisis of COVID-19 pandemic, we surveyed oncofertility centers from 14 developing countries (Egypt, Tunisia, Brazil, Peru, Panama, Mexico, Colombia, Guatemala, Argentina, Chile, Nigeria, South Africa, Saudi Arabia, and India). Survey questionnaire included questions on the availability and degree of utilization of fertility preservation options in case of childhood cancer, breast cancer, and blood cancer.

RESULTS

All surveyed centers responded to all questions. Responses and their calculated oncofertility scores showed different domestic standards for oncofertility practice in case of childhood cancer, breast cancer, and blood cancer in the developing countries under limited resource settings.

CONCLUSIONS

Medical practice in limited resource settings has become a critical topic especially after the global crisis of COVID-19 pandemic. Understanding the resources necessary to provide oncofertility treatments is important until the current COVID-19 pandemic resolves. Lessons learned will be valuable to future potential worldwide disruptions due to infectious diseases or other global crises.

FRI0607-HPR FREQUENCY AND PATIENTS BELIEFS ON VACCINATION IN RHEUMATIC DISEASES

Background:

Infectious diseases are increased in patients with rheumatic disorders; vaccination improves morbidity and mortality

Objectives:

The aim of this study was to describe the frequency of vaccination in patients with rheumatic disorders and to compare the results with those obtained in 2009 and 2013 in a similar population. We also identified factors leading to lack of vaccination and patients beliefs on vaccines.

Methods:

Multicentric cross sectional study in patients with autoinmune diseases from external rheumatology offices. Evaluation of vaccination status and patients´ knowledge about vaccines were studied. A comparative analysis was carried out with the series registered in 2009 and 2013 in a similar population.

Results:

179 patients (158 female, 88.3% and 21 male, 11.7%) were evaluated. Median age was 52 years. Main pathologies were: Rheumatoid Arthritis 65.9% (n:118), Systemic Lupus Erythematosus 11.7% (n:21), Systemic Sclerosis 3.9% (7), Sjogren Syndrome n = 3.4% (n:6), other diseases 15% (n: 27). Median disease duration: 8.87 years. Ninety three percent of patients (n:167) were taking inmunomodulators and 36.8% (n: 66) were using oral corticosteroids (20mg/day or less); 26,8% patients (n: 48) were receiving biological therapies. Vaccination frequency in the population was: Influenza 82% (147); 13-valent conjugate pneumococcal 69.3% (124), 23-valent pneumococcal 64.2% (115) and hepatitis B 62% (111). Comparative with 2009 and 2013 series there was an increase in the rate of vaccinated patients: influenza (82% vs. 39,1% and 74,2% respectively), antineumococcal (64% vs. 17% and 29%) and hepatitis B (62% vs. 6,7% and 26,7%).

Reasons for non-vaccination were absence of medical indication (41% of patients for hepatitis B; 32% for 23-valent pneumococcal; 38% for 13-valent pneumococcal and 34% for influenza).

139 patients (77, 7%) knew the benefits of vaccines, 164 (91, 6%) thought vaccines are useful; 134 (74,9%) reported that vaccines may decrease dying probability, 155 (86,5%) thought that vaccines are effective to prevent diseases and 149 patients (83,2%) believed that they prevent serious infections. 71 patients (39%) believed that vaccines can lead to serious consequences and 99 (55,3%) that they are more likely to acquire infections than the rest of the population.

Conclusion:

Frequency of vaccination has increased since 2009 but there is still misinformation regarding vaccines risks and benefits. Promotion and information is essential to improve adherence.

References:

[1]2019 update of EULAR recommendations for vaccination in adult patients with autoimmune inflammatory rheumatic diseases. Furer V, et al. Ann Rheum Dis 2020;79:39–52

[2] Vaccines and Disease-Modifying Antirheumatic Drugs: Practical Implications for the Rheumatologist. Friedman MA et al. Rheum Dis Clin North Am. 2017 Feb; 43 (1):1-13.

[3] Recommendations and barriers to vaccination in systemic lupus erythematosus. Garg M et al. Autoimmun Rev. 2018 Oct; 17 (10):990-1001.

[4] Comparison of national clinical practice guidelines and recommendations on vaccination of adult patients with autoimmune rheumatic diseases. Papadopoulou D. et al. Rheumatol Int. 2014 Feb;34 (2):151-63.

[5] Guías de recomendaciones de prevención de infecciones en pacientes que reciben modificadores de la respuesta biológica. Jordán R. Et al. Rev Arg Reumatol. 2014; 25 (2): 08-26.

Disclosure of Interests:

Malena Viola: None declared, Alejandro Benitez: None declared, Cecilia Garbarino: None declared, Gonzalo Rodriguez: None declared, Federico Benavidez: None declared, Claudia Peon: None declared, Eliana Soledad Blanco: None declared, Hernan Molina: None declared, Gimena Gómez: None declared, griselda redondo: None declared, Maria DeLaVega: None declared, Dario Mata: None declared, Augusto Riopedre: None declared, Osvaldo Messina Speakers bureau: Amgen; Americas Health Foundation; Pfizer

FRI0056 LUNG COMPROMISE SCREENING IN PATIENTS WITH EARLY RA. A MULTICENTRIC CROSS SECTIONAL STUDY

Background:

Rheumatoid arthritis (RA) affects 0.4-1.3% of general population (1). It can affect lungs in different ways, with interstitial lung disease (ILD) as the most severe. Clinically evident ILD has been reported in 10-42% of patients, with a great impact in prognosis (2).

Objectives:

Toidentify the prevalence of lung involvement in early rheumatoid arthritis patients (ERA) without previous known lung disease and describe the association between high resolution computed tomography (HRCT), lung functional tests (LFT) and clinical findings.

Methods:

Cross sectional multicentric study. We included ERA patients (1 year or less since diagnose) consecutively. Patients with previous RA related lung disease or biologic/targeted synthetic Dmard treatment were excluded. HRCT, immunological tests (rheumatoid factor, anti-CCP, ANA), LFT and clinical evaluation were performed.

Results:

We included 74 patients, 63 (85,1%) woman, mean (SD) of 47 (17,7) years. Thirty-seven patients (50%) were current or former smokers. Abnormal findings in HRCT were found in 62 patients (88,6%): ILD in 6 (8,6%), airway involvement in 40 (70%) and emphysema in 7 (10%). Ten patients (13,5%) had abnormal auscultation (2 sibilances, 2 roncus, and 6 crackles). Six patients (8,1%) had digital clubbing. Regarding immunological tests, 54/61 (88,5%) patients were positive for Anti CCP, and 53/61 (86,9%) were positive for FR. We compared features of patients with findings related to RA in HRCT (interstitial and/or airway) with those without them. We found no differences in the mean (SD) of DAS-28 [4,74 (1,38) vs 4,32 (1,39); p= 0,27]. The prevalence of anti- CCP was not higher in patients with abnormal HRCT [38/44 (86,3%) vs 16/17 (94,1%); p=0,39]. Patients with abnormal HRCT were older [median (IQR) 50,5 years (44,5-59,5) vs 43 years (32-51); p=0,008) and showed higher VSG values [mean (SD) 39,09 (24,03) vs 27,38 (17,6); p= 0,043]. Abnormal physical examination or dyspnea (class 2 mMRC or higher) was significantly associated with HRCT abnormalities [26 (50%) vs 3 (13,6%); p=0.003) and the presence of ILD on HRCT was significantly associated with crackles on the auscultation [4/68(6,25%) vs 2/6 (33,33%); p 0,023].

Conclusion:

This study shows a high prevalence of lung involvement in ERA patients of less 1 year from diagnosis. Also, we showed a significant association between HRCT and physical examination findings. This data highlights the importance of the clinical examination in Rheumatoid Arthritis patients. More studies with bigger samples and longitudinal follow up are needed to confirm and complete our results.

References:

[1]Rooney BK, Silman AJ. Epidemiology of the rheumatic diseases. Curr Opin Rheumatol [Internet]. 1999 Mar [cited 2016 Jul 19];11(2):91–7. Available from:http://www.ncbi.nlm.nih.gov/pubmed/10319210.

[2]Antin-Ozerkis D, Evans J, Rubinowitz A, Homer RJ, Matthay RA. Pulmonary Manifestations of Rheumatoid Arthritis. Clin Chest Med [Internet]. 2010;31(3):451–78. Available from:http://dx.doi.org/10.1016/j.ccm.2010.04.003.

Disclosure of Interests:

None declared

Regulatory Mechanisms of Soft Palate Development and Malformations

Orofacial clefting is the most common congenital craniofacial malformation, appearing in approximately 1 in 700 live births. Orofacial clefting includes several distinct anatomic malformations affecting the upper lip and hard and soft palate. The etiology of orofacial clefting is multifactorial, including genetic or environmental factors or their combination. A large body of work has focused on the molecular etiology of cleft lip and clefts of the hard palate, but study of the underlying etiology of soft palate clefts is an emerging field. Recent advances in the understanding of soft palate development suggest that it may be regulated by distinct pathways from those implicated in hard palate development. Soft palate clefting leads to muscle misorientation and oropharyngeal deficiency and adversely affects speech, swallowing, breathing, and hearing. Hence, there is an important need to investigate the regulatory mechanisms of soft palate development. Significantly, the anatomy, function, and development of soft palatal muscles are similar in humans and mice, rendering the mouse an excellent model for investigating molecular and cellular mechanisms of soft palate clefts. Cranial neural crest-derived cells provide important regulatory cues to guide myogenic progenitors to differentiate into muscles in the soft palate. Signals from the palatal epithelium also play key roles via tissue-tissue interactions mediated by Tgf-β, Wnt, Fgf, and Hh signaling molecules. Additionally, mutations in transcription factors, such as Dlx5, Tbx1, and Tbx22, have been associated with soft palate clefting in humans and mice, suggesting that they play important regulatory roles during soft palate development. Finally, we highlight the importance of distinguishing specific types of soft palate defects in patients and developing relevant animal models for each of these types to improve our understanding of the regulatory mechanism of soft palate development. This knowledge will provide a foundation for improving treatment for patients in the future.

Brentuximab vedotin and ESHAP is highly effective as second-line therapy for Hodgkin lymphoma patients (long-term results of a trial by the Spanish GELTAMO Group)

BACKGROUND

In this work, we assessed the efficacy and safety of brentuximab vedotin (BV) plus ESHAP (BRESHAP) as second-line therapy for Relapsed/Refractory Hodgkin lymphoma (RRHL) to improve the results before autologous stem-cell transplantation (ASCT).

PATIENTS AND METHODS

This was a multicenter, open-label, phase I-II trial of patients with RRHL after first-line chemotherapy. Treatment had three 21-day cycles of etoposide, solumedrol, high-dose AraC, and cisplatin. BV was administered at three dose levels (0.9, 1.2, and 1.8 mg/kg) intravenous on day ‒1 to 3 + 3 cohorts of patients. Final BV dose was 1.8 mg/kg. Responding patients proceeded to ASCT, followed by three BV courses (1.8 mg/kg, every 21 days). Main end points for evaluation were maximum tolerable dose and overall and complete response (CR) before ASCT.

RESULTS

A total of 66 patients were recruited (median age 36 years; range 18-66): 40 were primary refractory, 16 early relapse and 10 late relapse. There were 39 severe adverse events were reported in 22 patients, most frequently fever (n = 25, 35% neutropenic), including 3 deaths. Grade 3-4 hematological toxicity presented in 28 cases: neutropenia (n = 21), thrombocytopenia (n = 14), and anemia (n = 7). Grade ≥3-4 extrahematological adverse events (≥5%) were non-neutropenic fever (n = 13) and hypomagnesaemia (n = 3). Sixty-four patients underwent stem-cell mobilization; all collected >2×10e6/kg CD34+ cells (median 5.75; range 2.12-33.4). Overall response before transplant was 91% (CI 84% to 98%), including 70% (CRs 95% CI 59% to 81%). 60 patients were transplanted with no failure engraftments. Post-transplant response was CR in 49 patients (82% CI 73% to 91%) and partial responses in six (10% CI 5% to 15%). After a mean follow-up of 27 months, the 30-month time to treatment to failure was 74% (95% CI 68% to 80%), progression-free survival 71% (95% CI 65% to 77%), and overall survival 91% (CI 84% to 98%).

CONCLUSION

BRESHAP looks a safe and effective pre-transplant induction regimen, does not jeopardize transplant and allows long-term remissions and survival.

Geophysical investigations unravel the vestiges of ancient meandering channels and their dynamics in tidal landscapes

Whether or not one can detect relict signatures of the past imprinted in current landscapes is a question of the utmost theoretical and practical relevance for meandering tidal channels, owing to their influence on the morphodynamic evolution of tidal landscapes, a critically fragile environment, especially in face of expected climatic changes. Unravelling the sedimentary patterns of ancient channels is an expensive process that usually requires high resolution sediment coring. Here we use a novel inversion process of multi-frequency electromagnetic measurements to reveal the signature and characterize the dynamics of a salt-marsh paleo-meander in the Venice Lagoon. We show that the ancient meander migrated laterally while vertically aggrading, developing a peculiar bar geometry which is less common in analogous fluvial meanders. The observed point-bar dynamics and the associated architectural geometry are consistent with remote sensing and borehole data and contrast with current assessments of tidal meander morphodynamics mediated from classical fluvial theories. In addition, the proposed technique, rapid and non-invasive, bears important consequences for detecting buried stratal geometries and reconstructing the spatial distribution of ancient sedimentary bodies, providing quantitative data for the description of landscape evolution in time.

Prevalence of honeybee viruses in different regions of China and Argentina

Honeybees are threatened by various pathogens and parasites. More than 18 viruses have been described in honeybees and many of them have been detected in China and Argentina. In China, both Apis cerana and Apis mellifera are raised. In Argentina, beekeepers raise different ecotypes of A. mellifera: European honeybees (in both temperate and subtropical regions) and Africanised honeybees (in subtropical areas only). A thorough study was carried out in both China and Argentina to analyse the current virus presence and distribution in different climatic zones and gather information on different bee species/subspecies. Adult honeybees were collected from apiaries in temperate and subtropical regions of China (including areas with exclusive populations of A. mellifera, areas where A. mellifera and A. cerana co-exist, and areas with exclusive populations of A. cerana) and Argentina. Six viruses, namely, deformed wing virus (DWV), black queen cell virus (BQCV), sacbrood virus (SBV), chronic bee paralysis virus (CBPV), acute bee paralysis virus (ABPV) and Israeli acute paralysis virus (IAPV) were detected in China, both in A. cerana and in A. mellifera, while four viruses (DWV, BQCV, CBPV and ABPV) were present in Argentina. Interestingly, multiple infections were commonly found in China, with up to five different viruses co-circulating in some colonies without apparent abnormalities. In this study, no Chinese samples were positive for slow bee paralysis virus. The most prevalent viruses were BQCV (China) and DWV (Argentina). Kashmir bee virus was absent from samples analysed for both countries.

Abstract 784: Pharmacodynamic biomarkers in metronomic chemotherapy: Multiplex cytokine measurements in gastrointestinal cancer patients

Metronomic chemotherapy has shown promising antitumor activity in a number of malignancies. For example, we previously reported (Allegrini et al., Angiogenesis (2012) 15(2):275-86) a phase II clinical trial of metronomic UFT (a 5-fluorouracil prodrug; 100 mg/twice per day p.o.) and cyclophosphamide (CTX; 500 mg/mq2 i.v. bolus on day 1 and then 50 mg/day p.o.) plus celecoxib (200 mg/twice a day p.o.) in 38 patients with advanced refractory gastrointestinal tumors. The mechanisms of action of metronomic chemotherapy include upregulation of the angiogenesis inhibitor Thrombospondin-1, the suppression of bone marrow derived endothelial progenitor cells and, at least for drugs such as CTX, activation of the immune system. To further evaluate the latter, we carried out an immune system multiplex 14-cytokine profiling of plasma samples that were available (for day 0, day 28, and day 56) from 31 of the 38 patients in the above noted (Allegrini et al) clinical trial. Our results show that pre-treatment plasma level cut-offs of interferon-gamma (&gt;12.84pg/ml), sCD40L (&lt;2168pg/ml), interferon-alpha2 (&gt;55.11pg/ml), and IL-17a (&lt;15.1pg/ml) were predictive markers for those patients with better progression-free survival (p&lt;.05 for each cytokine). After 28 days of metronomic therapy, the plasma levels of sCD40L, IL-17a, and of IL-6 (&lt;130pg/ml) could serve as predictors of improved progression-free survival, as could levels interferon-gamma and sCD40L after 56 days of therapy. We observed minimal changes in cytokine profiles, from baseline, as a consequence of the metronomic therapy, with the exception of an elevation of IL-6 and IL-8 levels 28 days (and 56 days) after treatment started (p&lt;0.05). Our results indicate that a selective cytokine elevation, involving IL-6 and IL-8, following metronomic chemotherapy administration. In addition, interferon-gamma and sCD40L may be potential biomarkers for gastrointestinal cancer patients that are likely to benefit from metronomic chemotherapy. Our study contributes to our understanding of the mechanisms of action of metronomic chemotherapy, and may guide future patient selection criteria for metronomic chemotherapy for gastrointestinal cancers.

Citation Format: Paloma Valenzuela, Karla Parra, Derrick Oaxaca, Luis Reza, Jose Lopez, Montserrat Garcia Arreguin, Diana Garcia, Georgialina Rodriguez, Alfredo Falcone, Giacomo Allegrini, Teresa Di Desidero, Guido Bocci, Robert Kirken, Giulio Francia. Pharmacodynamic biomarkers in metronomic chemotherapy: Multiplex cytokine measurements in gastrointestinal cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 784. doi:10.1158/1538-7445.AM2017-784

Impact of CTLA-4 blockade in conjunction with metronomic chemotherapy on preclinical breast cancer growth

Background:

Although there are reports that metronomic cyclophosphamide (CTX) can be immune stimulating, the impact of its combination with anti-CTLA-4 immunotherapy for the treatment of cancer remains to be evaluated.

Methods:

Murine EMT-6/P breast cancer, or its cisplatin or CTX-resistant variants, or CT-26 colon, were implanted into Balb/c mice. Established tumours were monitored for relative growth following treatment with anti-CTLA-4 antibody alone or in combination with; (a) metronomic CTX (ldCTX; 20 mg kg⁻¹ day⁻¹), b) bolus (150 mg kg⁻¹) plus ldCTX, or (c) sequential treatment with gemcitabine (160 mg kg⁻¹ every 3 days).

Results:

EMT-6/P tumours responded to anti-CTLA-4 therapy, but this response was less effective when combined with bolus plus ldCTX. Anti-CTLA-4 could be effectively combined with either ldCTX (without a bolus), or with regimens of either sequential or concomitant gemcitabine, including in orthotopic EMT-6 tumours, and independently of the schedule of drug administration. Tumour responses were confirmed with CT-26 tumours but were less pronounced in drug-resistant EMT-6/CTX or EMT-6/DDP tumour models than in the parent tumour. A number of tumour bearing mice developed spontaneous metastases under continuous therapy. The majority of cured mice rejected tumour re-challenges.

Conclusions:

Metronomic CTX can be combined with anti-CTLA-4 therapy, but this therapy is impaired by concomitant bolus CTX. Sequential therapy of anti-CTLA-4 followed by gemcitabine is effective in chemotherapy-naive tumours, although tumour relapses can occur, in some cases accompanied by the development of spontaneous metastases.

Studio RMf della dominanza emisferica in destrimani e non destrimani

La valutazione non invasiva della dominanza emisferica per il linguaggio è una delle più promettenti applicazioni cliniche della risonanza magnetica funzionale, specie nei pazienti destinati alla neurochirurgia. In questo studio sono state eseguite due prove linguistiche in un gruppo di giovani volontari sani (8 destrimani, 12 non destrimani): una di fluenza fonemica ed una di associazione semantica. Tra i voxels statisticamente attivati nei due emisferi sono stati calcolati tre indici di asimmetria (emisferico, frontale e temporoparietale) in ogni soggetto e per ogni prova.

Nel complesso, la prova di fluenza fonemica attivava fortemente il lobo frontale, mentre la prova di associazione semantica determinava un pattern di attivazione piu distribuito, che comprendeva anche il giro temporale medio ed il giro angolare.

Per quanto riguarda gli indici di asimmetria, nei destrimani quello emisferico e quello frontale indicavano sempre l'attivazione prevalente dell'emisfero sinistro. Un solo soggetto ambidestro ha presentato nella prova di fluenza fonemica indici di asimmetria emisferico e frontale espressivi di lateralizzazione destra. D'altra parte, l'indice di asimmetria temporoparietale deponeva per una lieve revalenza dell'emisfero destro in un destrimane ed per una chiara lateralizzazione destra in un non destrimane.

La risonanza magnetica funzionale appare dunque metodica sensibile ed appropriata nella valutazione della dominanza emisferica per il linguaggio.

L'impiego di indici di asimmetria lobari può meglio evidenziare il differente contributo alla dominanza emisferica delle aree frontali rispetto a quelle temporoparietali. Infine, l'individuazione delle aree corticali correlate con la funzione linguistica è uno strumento potenzialmente utile per il neurochirurgo nel programmare resezioni di aree limitrofe.

Blood fatty acid composition in relation to allergy in children aged 2-9 years: results from the European IDEFICS study

BACKGROUND/OBJECTIVES

Blood polyunsaturated fatty acids (PUFA) are involved in allergy development, but the etiological role of n-6 and n-3 PUFA is still controversial. A European multicenter study of children (IDEFICS) provided the opportunity to explore the cross-sectional association between fatty acids (FA) and allergy.

SUBJECTS/METHODS

Blood FA levels were measured in 2600 children aged 2-9 years and were recorded as the percentage of weight of all FA detected. Logistic regression of allergy status on FA components was adjusted for age, sex, country, body mass index, family history of allergic disease, breast-feeding, and number of siblings. The results were given as odds ratios (OR) for current vs no allergy ever and an increase in FA by 1 s.d.

RESULTS

Overall, higher proportions of n-6 PUFA were associated with higher odds of allergy (OR=1.21 (1.05, 1.40)). Monounsaturated FA (MUFA) were associated with reduced risk for allergy (OR=0.75 (0.65, 0.87)), whereas saturated FA did not differ by allergy status. The strongest associations were observed in children <4 years old, with ORs of allergy given as 1.62 (1.15, 2.29) for n-3 PUFA and 0.63 (0.42, 0.95) for MUFA. With regard to individual FA, these associations were independently observed for docosapentaenoic acid (22:5 n-3) and oleic acid (18:1 n-9).

CONCLUSIONS

Both PUFA subtypes were positively associated with allergy in an age-dependent manner, whereas MUFA was associated with less allergy. The observation of high proportions of n-3 PUFA in allergic children younger than 4 years might help to understand the nature of early onset of atopic disease.

Sensitivity of imatinib-resistant T315I BCR-ABL CML to a synergistic combination of ponatinib and forskolin treatment

Tyrosine kinase inhibitors (TKIs) have dramatically improved the life expectancy of patients suffering from chronic myeloid leukemia (CML); however, patients will eventually develop resistance to TKI therapy or adverse side effects due to secondary off-target mechanisms associated with TKIs. CML patients exhibiting TKI resistance are at greater risk of developing an aggressive and drug-insensitive disease. Drug-resistant CML typically arises in response to spontaneous mutations within the drug binding sites of the targeted oncoproteins. To better understand the mechanism of drug resistance in TKI-resistant CML patients, the BCR-ABL transformed cell line KCL22 was grown with increasing concentrations of imatinib for a period of 6 weeks. Subsequently, a drug-resistant derivative of the parental KCL22 cell line harboring the T315I gatekeeper mutation was isolated and investigated for TKI drug sensitivity via multi-agent drug screens. A synergistic combination of ponatinib- and forskolin-reduced cell viability was identified in this clinically relevant imatinib-resistant CML cell line, which also proved efficacious in other CML cell lines. In summary, this study provides new insight into the biological underpinnings of BCR-ABL-driven CML and potential rationale for investigating novel treatment strategies for patients with T315I CML.

Abstract 3261: Impact of CTLA-4 blockade in conjunction with metronomic chemotherapy on preclinical breast cancer growth

Although we previously reported that metronomic cyclophosphamide can augment the anti-tumor impact of anti-CTLA-4 immunotherapy, the effectiveness of this strategy to treat drug resistant tumors remains to be evaluated. To that end, the parental, drug sensitive, EMT-6/P murine breast cancer, or its cisplatin (DDP) or cyclophosphamide (CTX) resistant variants, were implanted into Balb/c mice (n = 5-8 mice per group), either subcutaneously or orthotopically. Established tumors where monitored for relative growth following treatment with anti-CTLA-4 antibody (mouse anti-CD152, clone 9H10, given at 100ug on day 1 and 35ug on day 6, i.p.), alone or in combination with; a) metronomic CTX (ldCTX; 20mg/kg/day), b) Bolus (150mg/kg) plus ldCTX, or c) sequential treatment with gemcitabine (160mg/kg every 3 days).

EMT-6/P tumors responded to anti-CTLA-4 therapy, but this response was less effective when combined with Bolus plus ldCTX. Anti-CTLA-4 could be effectively combined with either ldCTX (without a bolus), or with a regimen of sequential gemcitabine. The EMT-6/P tumor showed consistent results in subcutaneous tumors and in those that were orthotopically implanted into the mammary fat pad. Tumor responses were less pronounced in drug resistant EMT-6/CTX or EMT-6/DDP tumor models than in the EMT-6/P tumor, but nonetheless even in the drug resistant models CTLA-4 targeting could be effectively combined with metronomic CTX or sequential gemcitabine (p&lt;0.05). A number mice implanted with the parent or with the drug resistant tumors developed spontaneous metastases under continuous therapy, including mice bearing subcutaneous tumors, and about 20% of the mice on the combination therapies showed complete tumor responses. Of these mice, over 90% rejected subsequent EMT/6 tumor grafts, indicating that the anti-CTLA-4 plus metronomic chemotherapy regimens did not impair immunological memory. Furthermore, the efficacy of a therapy of anti-CTLA-4 with sequential continuous gemcitabine was confirmed in an independent syngeneic CT-26 colon cancer model.

We conclude that metronomic chemotherapy can combined with anti-CTLA-4 therapy, both in syngeneic breast and colon cancer models, and in breast tumors selected in vivo for resistance to alkylating agents. Sequential therapy of anti-CTLA-4 followed by gemcitabine is effective in both chemotherapy naïve tumors and in tumors selected in vivo for resistance to CTX or to DDP, although tumor relapses can occur, in some cases accompanied by the development spontaneous metastases. Our results suggest a strategy for improving the anti-tumor efficacy of anti-CTLA-4 based therapies.

Citation Format: Karla Parra, Paloma Valenzuela, Alejandra E. Gallegos, Natzidielly Lerma, Luis Reza, Georgialina Rodriguez, Urban Emmenegger, Marian Manciu, Teresa Di Desidero, Guido Bocci, Mitchell S. Felder, Robert A. Kirken, Giulio Francia. Impact of CTLA-4 blockade in conjunction with metronomic chemotherapy on preclinical breast cancer growth. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3261.

Recursive Formulation of Operational Space Control

A recently developed spatial operator algebra approach to modeling and analysis of multibody robotic systems is used to develop O(n) recursive algorithms that compute the op erational space mass matrix and the operational space coriolis/centrifugal and gravity terms of an n-link serial manipulator. These algorithms enable an O(n) recursive im plementation of operational space control.

A Spatial Operator Algebra for Manipulator Modeling and Control

A recently developed spatial operator algebra for manipu lator modeling, control, and trajectory design is dis cussed. The elements of this algebra are linear operators whose domain and range spaces consist of forces, moments, velocities, and accelerations. The effect of these operators is equivalent to a spatial recursion along the span of a manipulator. Inversion of operators can be efficiently obtained via techniques of recursive filtering and smoothing. The operator algebra provides a high- level framework for describing the dynamic and kinematic behavior of a manipulator and for control and trajectory design algorithms. The interpretation of expressions within the algebraic framework leads to enhanced concep tual and physical understanding of manipulator dynamics and kinematics. Furthermore, implementable recursive algorithms can be immediately derived from the abstract operator expressions by inspection. Thus the transition from an abstract problem formulation and solution to the detailed mechanization of specific algorithms is greatly simplified.