Search

Background: The irregular use of antiretroviral therapy (ART) and late diagnosis still account for a large part of HIV-associated mortality in people living with HIV (PLHIV). Herein, we describe HIV-associated morbidity among hospitalised HIV/AIDS patients with advanced immunosuppression and assess the comorbidities, laboratory parameters, and immunological markers associated with mortality., Methods: The cross-sectional study was conducted at the Fundação de Medicina Tropical Doutor Heitor Vieira Dourado (FMT-HVD) in Manaus, Brazil. In all, 83 participants aged between 12 and 70 years were enrolled by convenience within 72 h of their hospitalisation. Clinical and laboratory data were obtained from electronic medical records. We prospectively measured the cytokines Th1/Th2/Th17 and inflammatory cytokines IL-8, IL-1β, and IL-12 using cytometric bead array, and the soluble CD14 using in-house enzyme-linked immunosorbent assay., Results: The HIV/AIDS inpatients presented a scenario of respiratory syndromes as the most prevalent comorbidity. Almost all patients had CD4 T counts below 350 cells/mL and the mortality rate was 20.5%. Pulmonary tuberculosis, neurotoxoplasmosis and oropharyngeal-esophageal candidiasis were the most prevalent opportunistic infections. TB and weight loss were more prevalent in HIV/AIDS inpatients who died. The Mann Whitney analysis showed that those who died had higher platelet distribution width (PDW) on admission, which is suggestive for platelet activation. The Poisson multivariate analysis showed the prevalence of TB, digestive syndrome and increases in IL-8 and lactate dehydrogenase (LDH) associated to death., Conclusions: The advanced immunosuppression characterized by the opportunistic infections presented in these HIV/AIDS inpatients was the major factor of mortality. The role of platelet activation in worse outcomes of hospitalisation and the IL-8 associated with the context of advanced immunosuppression may be promising markers in the prediction of mortality in HIV/AIDS patients., (© 2021. The Author(s).)

IL-4 plays an essential role in the activation of mature B cells, but less is known about the role of IL-4 in B cell maturation and tolerance checkpoints. In this study, we analyzed the effect of IL-4 on in vitro B cell maturation, from immature to transitional stages, and its influence on BCR-mediated negative selection. Starting either from purified CD19(+)IgM(-) B cell precursors, or sorted bone marrow immature (B220(low)IgM(low)CD23(-)) and transitional (B220(int)IgM(high)CD23(-)) B cells from C57BL/6 mice, we compared the maturation effects of IL-4 and BAFF. We found that IL-4 stimulated the generation of CD23(+) transitional B cells from CD23(-) B cells, and this effect was comparable to BAFF. IL-4 showed a unique protective effect against anti-IgM apoptotic signals on transitional B cell checkpoint, not observed with BAFF. IL-4 and BAFF strongly synergized to promote B cell maturation, and IL-4 also rendered it refractory to BCR-mediated cell death. IL-4 blocked upregulation of proapoptotic Bim protein levels induced by BCR crosslinking, suggesting that diminished levels of intracellular Bim promote protection to BCR-induced cell death. Evidence was obtained indicating that downmodulation of Bim by IL-4 occurred in a posttranscriptional manner. Consistent with data obtained in vitro, IL-4 in vivo was able to inhibit Bim upregulation and prevent cell death. These results contribute to the understanding of the role of IL-4 in B lymphocyte physiology, unveiling a previously undescribed activity of this cytokine on the maturation of B cells, which could have important implications on the breaking of B cell central tolerance in autoimmunity., (Copyright © 2014 by The American Association of Immunologists, Inc.)