Relationship among serum levels of IL-6, sIL-6R, s gp130 and CD126 on T-cell in HIV-1 infected and uninfected men participating in the Los Angeles Multi-Center AIDS Cohort Study

INTRODUCTION

Interleukin 6 (IL-6) activates cells through its unique heterodimeric signaling complex of IL-6 receptor (IL6R) subunit and interleukin 6 signal transducer β-subunit glycoprotein 130 (gp130). The objective of this study was to investigate associations among serum levels of IL-6, sIL-6R, sgp130 and relative fluorescence intensity (RFI) of the α-subunit of the IL-6 receptor (CD126) on T-cells of HIV-1 infected and uninfected men.

METHODS

Blood samples were obtained from 69 HIV-1-infected men on Highly Active Antiretroviral Therapy (HAART) with mean age of 49.1 and 52 HIV-1-uninfected with mean age of 54.3 years -. All men were participating in the Los Angeles Multi-Center AIDS Cohort Study (MACS). Serum levels of IL-6, sIL-6R, sgp130 were measured by enzyme-linked immunoassays and T-cell phenotypic analysis and RFI of CD126 on CD4+ and CD8+ by flow cytometry.

RESULTS

Mean serum levels of IL-6, sIL6R, sgp130 and of CD126 RFI on CD4+ were 4.34 pg/mL, 39.3 ng/mL, 349 ng/mL and 526 RFI respectively for HIV-1-infected men and 2.74 pg/mL, 41.9 ng/mL, 318 ng/mL and 561 RFI respectively for HIV-1-uninfected men. The mean serum concentrations of IL-6, sIL-6R in HIV-1-infected and uninfected men were not significantly different (p>0.05). There was a positive correlation between plasma HIV-1 RNA and the levels of IL-6 (p<0.001), sIL6R (p = 0.002) but no correlation with sgp130 (p = 0.339). In addition, there was a negative correlation between serum levels of IL-6 with RFI of CD126 on CD4+ (p = 0.037) and a positive correlation between serum levels of sgp130 (p = 0.021) and sIL-6R in HIV-1-infected men.

CONCLUSION

Knowledge of biological variation, differences in the blood levels of biomarkers among healthy individuals and individuals experiencing illness, are very important for selection of appropriate tests for stage and progression of disease. Our data suggest no correlation among IL-6, and sIL-R6, in the treated phase of HIV-1 infection. The action and blood level of IL-6 and its receptors may be different at each stage of a disease progression.

Differences in COVID-19 testing and adverse outcomes by race, ethnicity, sex, and health system setting in a large diverse US cohort

BACKGROUND

Racial/ethnic disparities during the first six months of the COVID-19 pandemic led to differences in COVID-19 testing and adverse outcomes. We examine differences in testing and adverse outcomes by race/ethnicity and sex across a geographically diverse and system-based COVID-19 cohort collaboration.

METHODS

Observational study among adults (≥18 years) within six US cohorts from March 1, 2020 to August 31, 2020 using data from electronic health record and patient reporting. Race/ethnicity and sex as risk factors were primary exposures, with health system type (integrated health system, academic health system, or interval cohort) as secondary. Proportions measured SARS-CoV-2 testing and positivity; attributed hospitalization and death related to COVID-19. Relative risk ratios (RR) with 95% confidence intervals quantified associations between exposures and main outcomes.

RESULTS

5,958,908 patients were included. Hispanic patients had the highest proportions of SARS-CoV-2 testing (16%) and positivity (18%), while Asian/Pacific Islander patients had the lowest portions tested (11%) and White patients had the lowest positivity rates (5%). Men had a lower likelihood of testing (RR = 0.90 [0.89-0.90]) and a higher positivity risk (RR = 1.16 [1.14-1.18]) compared to women. Black patients were more likely to have COVID-19-related hospitalizations (RR = 1.36 [1.28-1.44]) and death (RR = 1.17 [1.03-1.32]) compared with White patients. Men were more likely to be hospitalized (RR = 1.30 [1.16-1.22]) or die (RR = 1.70 [1.53-1.89]) compared to women. These racial/ethnic and sex differences were reflected in both health system types.

CONCLUSIONS

This study supports evidence of disparities by race/ethnicity and sex during the COVID-19 pandemic that persisted even in healthcare settings with reduced barriers to accessing care. Further research is needed to understand and prevent the drivers that resulted in higher burdens of morbidity among certain Black patients and men.