ABSTRACT
Background: Severe COVID-19 outcomes have been reported in people living with HIV (PLWH). High SARS-CoV-2 RNAemia has emerged as a hallmark of severe COVID-19, yet its pathogenic role in the context of COVID-19 in PLWH is currently unknown. We hereby measured SARS-CoV-2 RNAemia and explored its association with T-cell/humoral responses and clinical severity in PLWH. Method(s): Unvaccinated PLWH and age/sex-matched people living without HIV (PLWOH) hospitalized for radiologically-confirmed COVID-19 pneumonia were consecutively enrolled (March 2020-January 2021). We measured: SARS-CoV-2 RNAemia (RT-qPCR);T-cell activation (HLA-DR+CD-38+), cytotoxic T-cells [granzyme-B(GRZB)+perforin(PRF)+], GRZB/PRF production (MFI) by cytotoxic T-cells (flow cytometry);SARS-CoV-2-specific cytokines (IFN-gamma/ TNF-alpha/IL-2/IL-4/IL-17A)-producing T-cells, after SARS-CoV-2 spike peptides challenge (flow cytometry);anti-RBD antibodies (ELISA), Spike-ACE2 binding inhibition (receptor binding inhibition assay). Statistics: Mann-Whitney test and Spearman's correlation. Result(s): 18 PLWH (16 on cART;median CD4 361.5/mL;HIV-RNA< 50 cp/ mL in 15/18) and 18 PLWOH were included at a median of 10 days from symptoms onset (Fig.1A). PLWH had lower PaO2/FiO2 [140 (122-151.5) vs. 207 (156.3-309.3);P=0.0005] and higher SARS-CoV-2 RNAemia (Fig.1B). While humoral responses were comparable between groups ( Fig.1C-D), as was T-cell activation, PLWH showed skewed T-cell responses: higher perforin production by cytotoxic T-cells (Fig.1E);fewer SARS-CoV-2-specific IFN-gamma+ and IL-4+ CD4 T-cells (Fig.1F);lower Th1 tri-functional (IFN-gamma+TNF-alpha+IL-2+) and bi-functional (IFN-gamma+TNF-alpha+) CD4 T-cells (Fig.1G);reduced TNF-alpha+ CD8 T-cells (Fig.1H). Interestingly, SARS-CoV-2 RNAemia correlated negatively with PaO2/FiO2 nadir and SARS-CoV-2-specific T-cells, yet positively with perforin production by cytotoxic T-cells (Fig.1I-M). No correlations between RNAemia and humoral responses were found. Conclusion(s): As compared to HIV-uninfected patients, PLWH hospitalized for COVID-19 pneumonia feature high SARS-CoV-2 RNAemia which is linked to respiratory failure and skewed T-cell responses, with higher perforin production by cytotoxic T-cells, and yet fewer polyfunctional SARS-CoV-2-specific T-cells. Our data suggest a link between HIV-related T-cell dysfunction and poor control over circulating SARS-CoV-2 that may in turn influence COVID-19 severity in PLWH. (Figure Presented).
ABSTRACT
Background. We studied immunological response against SARS-CoV-2 after two doses of vaccine in health care workers (HCW) at our Infectious Disease Unit Methods. We enrolled prospectively HCW without (group A) and with previous infection (group B). We collected peripheral blood at baseline (before the BNT162b2 vaccine), T1 (before the 2nd dose), T2 and T6 (after 1 and 6 months after of 2nd dose). The activation induced cell marker assay (AIM) was performed with CD4 and CD8 Spike peptide megapools (MPs). We evaluated the Stimulation Index (SI) as AIM+ stimulated cells/negative control (positive response SI >= 2). Quantitative antibodies (Abs) to Spike-1 protein (S) and to nucleocapside protein (N) were detected with an electrochemiluminescence immunoassay. We tested at T6 the responses to alpha, beta, gamma, delta and epsilon variants MPs.We used the linear mixed model with random intercept adjusted for age and sex to compare specific times to T0. To assess differences over time between groups the interaction with time was tested. Results. In group A 13/22 (59%) were female vs 5/7 (71%) group B, the mean age 40 vs 38 years, respectively. For CD4+ Spike the overall rate of change over time was significant at T1 (p=0.038) and at T2 (p< 0.001) vs T0 with a decreasing at T6 (p not significant) [Figure 1] with a trend of higher response in group A. In group B the CD8 + Spike reactivity increased at T1(p=0.037) and at T6 (p=0.005) vs T0. The interaction between SI and time was statistically significant at T1 (p=0.033);T2 (p= 0.046) and T6 (p=0.035) (mean values in group B higher than A). For overall population, the anti-S Abs significantly increased at T1 vs T0, T2 vs T0 and at T6 vs T0 [Figure 2A]. The group B at T6 retained a higher anti S response but the rate of change significantly differs between the two group (overall interaction: p< 0.001) [Figure 2B]. At T6 in both groups we found a high CD4+ T cells response to epsilon variant, even if not detected as circulant virus. Conclusion. The humoral response was persistent and increased in previous infected subjects. The CD4+T cells response after vaccination retained a response in uninfected subject, with an increasing trend and with a response to non-circulating variants. The vaccine could help the CD8+ T cells reactivity specific for Spike peptides.