Proton pump inhibitors and antibiotics impact on toxicities and clinical outcomes in cancer patients treated with immunotherapy

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Background: Gut microbiome dysbiosis impairs systemic immune responses and recent evidence suggests its critical role in patients (pts) treated with immune checkpoint inhibitors (ICI). Proton pump inhibitors (PPI) and antibiotics (ATB) may alter the microbiome and their impact on clinical outcomes and toxicities requires further investigation. Methods: This retrospective cohort included consecutive metastatic cancer pts treated with ICI with palliative intent. We reviewed pts' records, concomitant medication and toxicities graded by CTCAE 4.0. Pts with PPI or ATB exposure were analyzed according to previous use (pPPI and pATB, ≤60 days to ICI) and concomitant use (cPPI and cATB). We estimated median overall survival (mOS) and progression free survival (PFS) by Kaplan–Meier and used a Cox proportional-hazards model to adjust for differences in baseline characteristics. Toxicities and ATB/PPI interaction was calculated using Pearson Chi-square method. Results: We enrolled 216 pts with a median age of 59 years, mostly ECOG-PS 0 (34%) or 1 (58%). ICI employed were mostly anti-PD-1 (60.2%), anti-CTLA-4 (16.2%) and anti-PD-L1 (12.5%). Most frequent primary tumor sites were lung n = 39 (18.1%), gastrointestinal n = 34 (15.7%) and melanoma n = 33 (15.2%). Half of the pts (108) received ATB and 114 (52.8%) PPI. Compared to control, pPPI group n = 57 (26.4%) had shorter mOS (11.6m vs 19.7m, p < 0.001) and PFS (2.8m vs 8.5m, p < 0.001), but no statistically significant difference in toxicities grade ≥3 and/or leading to ICI discontinuation (36% vs 29.1%; p = 0.29). cPPI n = 100 (46.3%) depicted a negative impact on mOS (12.1m vs 17.0m; p = 0.01), PFS (4.3m vs 7.1m; p = 0.04) and augmented toxicities (42% vs 19%; p < 0.001). pATB n = 34 (15.7%) had shorter OS (6.9m vs 19.3m, p < 0.001) and PFS (3.2 vs 7.2m, p = 0.005) and higher incidence of toxicities (45.9% vs 28.1%; p = 0.04 ). cATB use n = 92 (42.6%) did not impact OS (12.1m vs 15.6m; p = 0.32) or PFS (5.5m vs 5.9m; p = 0.82), but had a higher incidence of toxicities: 37% vs. 24.2% (p = 0.05). Multivariate analyses confirmed that pATB therapy and pPPI respectively remained as independent prognostic variables associated with OS (HR 2.39; 95% CI, 1.60-3.59; P <.001 and HR 1.73; 95% CI 1.23-2.44; P = 0.002) and PFS (HR 1.72; 95% CI, 1.14-2.61; P = 0.01 and HR 2.36; 95% CI 1.67 - 3.34; P < 0.001) adjusted by performance status, age and line of treatment. Conclusions: These data suggest that concomitant use of PPI and ATB is associated with increased toxicities in ICI treated pts. pPPI and pATB can negatively impact OS and PFS and merit clinician’s attention.

Attendences on health to riverine population living in the banks of Amazon river, Amapa, Brazil

Introduction

The riverine population resident at banks of Amazon river (Amapá, Brazil) has particularities related to health-disease process and socioepidemiologic demands, that represents a challenge for appointment of professionals in the unique health system. The project Mandic Borderless has a purpose to attend, in a complete and humanized way, populations without assistance in places of difficult access.

Objectives

Describe the experience and results obtained from the health care to riverine population in the region along Amazon River, Amapá, Brazil, attended during an expedition in 2020. Descriptive cross-sectional survey. The health-care staff that performed the consultations was composed of doctor, dentists, nurses and medical students, who work in a college located in the interior of the state of São Paulo.

Results

About 4,500 riverine populations were attended indirectly and other 1,775 directly by many medical specialties, such as: clinical medicine, gynecology, pediatrics, ophthalmology, dermatology, ultrasonography, nursery and odontology work for free. And also collective health education actions were carried out, addressing topics such as: oral health, scabies, pediculosis (lice), first aid, hypertension, diabetes, sexually transmitted diseases prevention and contraceptive methods. More than 300 patients received toothpaste kits and were instructed about oral health.

Conclusions

The expedition collected data about isolate population showing their necessary and provide an innovated experience in the medical teachings, considering the knowledge about the disease health process and the integrated and humanity care.

Key messages

Provide for medical students a vision about communities who lives in a geographic isolation. There are necessary of an upgrade in access a basic e essential services for the riverine population.

Multiple epitopes of HLA-DRB1*0411 are recognized by T-cell clones originated from individuals carrying other DR4 subtypes

HLA polymorphism dictates the binding and recognition of specific peptides, leading to variations in individual immune responses and may contribute to autoimmune disorders and outcome in organ transplantation. We have studied the molecular basis for the cellular recognition of DRB1*0411 in individuals carrying other sequence-related DR4-alleles by characterization of T-cell clones (TLC). A set of 166 TLC were raised by priming cells from DRB1*0401,0402 and DRB1*0405,0901 individuals and 52 of them recognized DRB1*0411. Five distinct patterns of T-cell allorecognition were found: DRB1*0411 alone, DRB1*0411 and 0405, DRB1*0411 and 0406, DRB1*0411 and 0407 and DRB1*0411, 0406 and 0407, depending on responder phenotypes and epitopes recognized by their T cells. A stretch of 30 amino acids on DRB1*0411 from positions 57 to 86 behaves as a functional domain and residues S57, R71, E74 and V86 seem to be crucial in forming immunogenic determinants recognized by these TLC. The knowledge of shared amino acid residues between closely related DR4 alleles, which show similar patterns of recognition by T cells could also be useful in the selection of prospective donors for clinical transplantation of solid organs or bone marrow.

Microvariation creates significant functional differences in the DR3 molecules

Two DR3 molecules differ by four amino acids whose side chains point into the DR antigen-binding groove. To begin to assess the role of microvariation on DR3 function, DRB1*0302 residues were replaced with DRB1*0301 residues at beta-chain positions 26, 47, 86, and 47 plus 86. Murine fibroblast cell lines expressing DR(alpha, beta 1*0301), DR(alpha, beta 1*0302), and the four mutant 0302 molecules were examined for alloproliferative DR(alpha, beta 1*0302)-specific TLC stimulation and peptide binding. Changing position 26 had the most profound effect on T-cell recognition (seven of nine TLCs did not respond). Two TLCs did not respond to the mutant 0302V86 molecule and four TLCs that did respond to this mutant lost responsiveness when positions 47 and 86 were mutated together. These data suggest that each of these variant residues, including position 47, influence T-cell recognition. Surprisingly, none of the mutations had an effect on the absolute binding of HA 307-319 (DR[alpha, beta 1*0302] specific) and HSP 3-13 (DR[alpha, beta 1*0301] specific); however, the mutant 0302 molecules changed at position 86 (glycine to valine) consistently bound HA 307-319 at significantly higher levels than DR(alpha, beta 1*0302). These data for position 86 are in contrast to other DR molecules and indicate that peptide contact residues for a specific DR molecule cannot be predicted based on binding results obtained with other DR molecules. These data suggest that each of these variant groove residues, although not accessible to the TCR, contribute to the significant functional differences between the DR3 microvariants through subtle influences on the DR3-peptide complex.

HLA antigens and other genetic markers in the Mapuche Indians of Argentina

A total of 107 Mapuche Indians living in western Argentina were studied with respect to 16 genetic systems. For HLA, there were a few differences in relation to previous studies; and considering the averages observed in 15 other South American tribes, Mapuche Indians showed low values for A2, A9 and C3, but high ones for A28 and B16. This is the first report of the presence (in low frequencies, 1-6%) of alleles C2, C6 and C7, as well as of DR antigens (most frequent alleles DR4 and DR2) in South American Indians. Some peculiar reactions shown by products of locus B suggest the presence of antigens that are characteristic of the Mapuche. As for the other systems, the frequencies of R1 (Rh) and PGM1(1) were lower but those for r (Rh), GLO1 and Hp1 were higher than the averages obtained considering previous studies of this ethnic group. Other salient findings were the variability observed in the PGM2 and C3 systems, and the low prevalence of Bfs.