Coassociations between IL10 polymorphisms, IL-10 production, helminth infection, and asthma/wheeze in an urban tropical population in Brazil.

BACKGROUND: Helminth infections are associated with protection against allergies. It is postulated that IL-10 production after helminth infection suppresses skin hypersensitivity and increases IgG4 production, protecting against allergies. OBJECTIVE: We aimed to determine whether IL10 polymorphisms are associated with helminth infection and the risk of wheeze and allergy. METHODS: Twelve IL10 single nucleotide polymorphisms were genotyped in 1353 children aged 4 to 11 years living in a poor urban area in Salvador, Brazil. Wheezing status, Ascaris lumbricoides and Trichuris trichiura infection, IL-10 production by peripheral blood leukocytes stimulated with A lumbricoides extract, serum total IgE levels, specific IgE levels, skin prick test responses to common aeroallergens, and IgG4 and IgE anti-A lumbricoides antibody levels were measured in all children. Association tests were performed by using logistic or linear regression when appropriate, including sex, age, helminth infection, and principal components for ancestry informative markers as covariates by using PLINK. RESULTS: Allele G of marker rs3024496 was associated with the decreased production of IL-10 by peripheral blood leukocytes in response to A lumbricoides stimulation. Allele C of marker rs3024498 was negatively associated with helminth infection or its markers. Marker rs3024492 was positively associated with the risk of atopic wheeze, total IgE levels, and skin prick test responses to cockroach. CONCLUSIONS: Our findings suggest that IL10 polymorphisms might play a role in the production of IL-10, helminth infection, and allergy. We hypothesize that polymorphisms related to protection against helminths, which would offer an evolutionary advantage to subjects in the past, might be associated with increased risk of allergic diseases.

Genetic variants in the TNF pathway impact TNFi response in a mixed population with rheumatoid arthritis.

Rheumatoid arthritis (RA) is a multifactorial autoimmune inflammatory disease that mainly affects the joints, on reducing functional capacity and impacting quality of life. Cytokines such as tumor necrosis factor (TNF) and interleukin 6 (IL-6) are crucial in the pathogenesis and treatment of this disease. Some patients using TNF inhibitors (TNFi) do not respond or lose their response to these medications. Clinical, sociodemographic, and genetic data were used to evaluate the associations of single nucleotide polymorphisms (SNP) in TNF, TNFRSF1A, and TNFRSF1B genes with the diagnosis of RA, standardized score results, laboratory tests, and response to TNFi. In one subsample, TNF and IL-6 serum levels cytokines were performed. A total of 654 subjects (360 healthy controls and 294 diagnosed with RA) were included in the analysis. Higher levels of TNF have been found in individuals diagnosed with RA. IL-6 levels were higher in individuals who did not respond to TNFi treatment, while responders had levels comparable to those without the disease. No associations were found between the SNPs studied and the diagnosis of RA; however, rs767455-C seems to play a role in the response to golimumab treatment, being related to better therapeutic response and lower mean serum leukocyte levels. In addition, rs1061622-G was associated with poorer functional capacity and rs1800629-A was associated with higher leukocyte values and serum transaminase levels. The rs1061622-G and rs767455-C may play a role in the response to TNFi treatment, especially for patients using golimumab, although they do not seem to be associated with the diagnosis of RA. Polymosphisms in the TNF pathway may impact baseline levels of immune cells and markers of renal and hepatic function in RA patients. Our results highlight the importance of evaluating the impact of these polymorphisms on TNFi response and safety, particularly in larger-scale studies.

Heterozygote Advantage of the Type II Deiodinase Thr92Ala Polymorphism on Intrahospital Mortality of COVID-19.

CONTEXT: The type 2 deiodinase and its Thr92Ala-DIO2 polymorphism have been linked to clinical outcomes in acute lung injury and pulmonary fibrosis. OBJECTIVE: Our objectives were to evaluate were cumulative mortality during admission according to Thr92Ala-DIO2 polymorphism. METHODS: Here we conducted an observational, longitudinal, and prospective cohort study to investigate a possible association between the Thr92Ala-DIO2 polymorphism and intrahospital mortality from COVID-19 in adult patients admitted between June and August 2020. Blood biochemistry, thyroid function tests, length of stay, comorbidities, complications, and severity scores were also studied according to Thr92Ala-DIO2 polymorphism. RESULTS: In total, 220 consecutive patients (median age 62; 48-74 years) were stratified into 3 subgroups: Thr/Thr (n = 79), Thr/Ala (n = 119), and Ala/Ala (n = 23). While the overall mortality was 17.3%, the lethality was lower in Ala/Thr patients (12.6%) than in Thr/Thr patients (21.7%) or Ala/Ala patients (23%). The heterozygous genotype (Thr/Ala) was associated with a 47% reduced risk of intrahospital mortality whereas univariate and multivariate logistic regression adjusted for multiple covariates revealed a reduction that ranged from 51% to 66%. The association of the Thr/Ala genotype with better clinical outcomes was confirmed in a metanalysis of 5 studies, including the present one. CONCLUSION: Here we provide evidence for a protective role played by Thr92Ala-DIO2 heterozygosity in patients with COVID-19. This protective effect follows an inheritance model known as overdominance, in which the phenotype of the heterozygote lies outside the phenotypical range of both homozygous.

New Challenge for Zika Virus Infection: Human Reservoirs?

Zika virus (ZIKV) is considered to cause an acute self-limited infection in adults, and microcephaly in fetus. Presence of the virus for long periods has been detected in body fluids; however, persistent viremia in serum for more than 1 year has not yet been reported. We have investigated persistence of ZIKV in serum samples of 77 subjects who were infected by the virus between 18 months and 3 years before the start of this study. The subjects included children with microcephaly and their parents. Serum samples were subjected to routine RT-qPCR assay for ZIKV, Chikungunya virus, and Dengue virus. From the 77 subjects, five showed positive for the presence of ZIKV particles by RT-qPCR, including four members of the same family. Viral isolation in Vero cells and C6/36 cells confirmed the result and showed the viral particles were active. We have detected viremia in healthy carriers up to 3 years after symptom onset. Humans acting as potential viral reservoirs have major implication for the current understanding of ZIKV infection.