ABSTRACT
Background: Understanding the adaptive immune response to SARS-CoV-2, kinetics, persistence and their relationship with the disease severity would be crucial in order to predict recurrences, reinfections and could serve in the design of vaccination strategies. We sought to characterize IgG and neutralizing antibodies (NAbs) against SARS-CoV-2 in patients who were admitted to hospital with COVID-19 disease. Methods: All patients admitted between March-April 2020 with moderate, severe and critical SARS-CoV-2 pneumonia were prospectively studied. Clinical, laboratory data and IgG against SARS-CoV-2 levels were assessed at baseline (upon admission) and months 1, 3 and 6. NAbs were assessed at month 1, 3 and 6. IgG against the SARS-CoV-2 spike (S) protein was measured in serum by chemiluminescence (LIAISON® SARS-CoV-2 S1/S2, DiaSorin) and results were expressed in arbitrary units (AU)/mL. The neutralizing activity of plasma samples was analyzed in a 293T/hACE2 cell infection test using a surrogate viral inhibition assay that uses human immunodeficiency virus type 1 (HIV-1)-based virus expressing SARS-CoV-2 S protein and Luciferase. For neutralization assays, pseudoviruses were incubated with increasing plasma dilutions (range 1/60-1/14,580) in order to obtain the ID50 values. Results: A total of 110 patients who were discharged from hospital were recruited. Median (range) age was 61 (57-71);61.2% were male and most reported comorbidities were hypertension (39.6%), diabetes (24.3%) and obesity (19.8%). Median time from symptoms onset to admission was 9 days (range 7-11). Median (range) IgG levels (AU/mL) at baseline and months 1, 3 and 6 were 48 (28-81), 168 (134-210), 140 (112-171) and 146 (104-206) respectively. No significant differences were observed in median IgG fold change values up to month 6 among severity groups. Median (range) ID50 values for NAbs at months 1, 3 and 6 were 3938 (1958-6407), 4344 (2335-6752) and 424 (124-1022) respectively. NAb titers presented a significant decrease (overall-10.2-fold change from maximal values) without differences among severity groups (Figure 1 a and b). No reinfections occurred. Conclusion: Specific humoral immune response to SARS CoV-2 in patients requiring hospital admission characterizes for a clear peak between 30 and 90 days after admission followed by a significant decline in titer of NAbs by day 180 regardless of disease severity. Longer follow-up may help to determine the longevity of the specific immune response.
ABSTRACT
Background: Within a prospective cohort of people with HIV (PWH) in Spain, we assessed the prevalence of SARS-CoV-2 antibodies (Ab), the proportion of asymptomatic COVID-19, and identified predictors of infection. Methods: We determined SARS-CoV-2 Ab in plasma samples collected from April 1st to September 30th, 2020, from enrollees in the Spanish HIV Research Network Cohort (CoRIS), a prospective national cohort of PWH, naive to ART at study entry, seen for the first time from January 1st, 2004. Samples were stored at-80°C in the Spanish HIV BioBank, and serology was performed using the Platelia SARS-CoV-2 Total Ab assays (BioRad, Hercules, CA, USA). Illness severity (NIH criteria) was assessed by medical records review and, if needed, participant interviews. Multivariable logistic regression analysis was used to identify predictors of seropositivity among the following variables: sex, age, country of birth, education level, comorbidities (hypertension, chronic heart disease, diabetes, non-AIDS related cancer, chronic kidney disease, cirrhosis), route of HIV acquisition, prior AIDS, CD4+ cell count, HIV viral load, and N(t)RTI backbone. Results: During the study period, blood samples were collected and stored in the HIV BioBank from 1,076 consecutive PWH in CoRIS: 88.0% male at birth, median age 43 yr., 72.3% MSM, 97.7% on ART, median CD4+ 688 cells/mm3, 91.4% undetectable HIV viral load. SARS-CoV-2 Ab were detected in 91 PWH, for a seroprevalence of 8.5% (95%CI: 6.9%-10.3%). A total of 41 PWH (45.0%) had asymptomatic infections;the disease was mild in 43 (47.3%), moderate in 4 (4.4%), severe in 3 (3.3%), and 0 critical. Seven PWH (7.7%) were hospitalized. COVID-19 was confirmed by RT-PCR in 22 (24.2%) PWH. Variables independently associated with SARS-CoV-2 seropositivity were birth in Latin American (LA) Countries vs. Spain (adjusted odds ratio [aOR]: 2.34, 95%CI: 1.42-3.85;P=.001);arterial hypertension (aOR: 1.63, 95%CI: 1.00-2.67;P=.050);and therapy with tenofovir disoproxil fumarate plus emtricitabine (TDF/FTC) vs tenofovir alafenamide (TAF)/FTC as the N(t)RTI backbone (aOR: 0.32, 95%CI: 0.12-0.84;P=.021). (Table). Conclusion: A large proportion of SARS-CoV-2 infections among PWH were asymptomatic. Birth in LA-countries and arterial hypertension were associated with increased risk of SARS-CoV-2 seropositivity. Our analysis, adjusted by comorbidities and other variables, suggest that TDF/FTC may prevent SARS-CoV-2 infection among PWH. (Figure Presented).