ABSTRACT
Introduction Anti-spike severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies produced after infection with the coronavirus disease of 2019 (COVID-19) will offer protection and prevent re-infection for a few months. Seroprevalence studies measuring the SARSCoV-2 immunoglobulin G (IgG) levels will be helpful to know the herd immunity level that prevents community transmission. Very few studies have addressed the antibody titer among healthy participants and rheumatoid arthritis (RA) patients. The present study was conducted to determine the anti-spike SARS-CoV-2 antibody (Ab) status before COVID-19 vaccination in healthy participants and RA patients. Methodology A cross-sectional study was conducted at a tertiary care hospital to estimate the serum anti-spike antibody levels against COVID-19 among the pre-vaccinated healthy participants and patients with RA during the third wave of COVID-19. After receiving written informed consent, participants were recruited as per the inclusion and exclusion criteria. Demographic details, co-morbid status, and medication details were collected. Five milliliters of blood samples were collected, and anti-spike antibodies were estimated. The SARS-CoV-2 Ab positivity rate was expressed in percentage and was correlated with gender and age groups. Ab-positive participants were classified into three categories based on the neutralizing antibody titers (NAT). Results A total of 58 participants (49 healthy volunteers and nine RA patients) were recruited. Out of 58 participants, 40 were males, nine were females among healthy participants, and one male and eight females in the RA group were enrolled. Among the RA patients, one participant was found to have the chronic obstructive pulmonary disease (COPD), and two participants with hypothyroidism. Antibody positivity was found to be 83.6% among the healthy volunteers and 100% in the RA patients. About 48% had NAT between 50 and 90%. There was no significant difference for age and gender-specific positivity for SARS-CoV-2 neutralizing antibodies and neutralizing antibody titers among healthy participants. Conclusion Our study showed 84% positivity for anti-spike SARS-CoV-2 antibodies around the third wave (between November 2021 and February 2022). The majority had high neutralizing antibody titers. The probable reason for the SARS-CoV-2 antibody positivity before vaccination was either asymptomatic infection or herd immunity.
ABSTRACT
Background: The graded exercise stress treadmill test (GXT) is among the most frequently performed tests in cardiology. The COVID-19 pandemic led many healthcare facilities to require patients to wear a mask. This study evaluated the effect of the surgical face mask on exercise capacity and perceived exertion. Methods: In this prospective, randomized crossover trial, 35 healthy adults performed a GXT using the Bruce protocol with a surgical mask, and without a mask. The primary outcome was exercise capacity in metabolic equivalents (METs), and the secondary outcome was exercise perception on the modified Borg scale (from 0 to 10). Effort duration, heart rate, oxygen saturation, and blood pressure were also analyzed. Results: Exercise capacity was reduced by 0.4 MET (95% confidence interval [CI] -0.7 - -0.2) during the GXT with a mask (11.8 ± 2.7 METs vs 12.3 ± 2.5 METs, p = 0.001), and the final perceived effort increased by 0.5 point (CI 0.2 - 0.8; 8.4 ± 1.3 vs 7.9 ± 1.6, p = 0.004). Effort duration was cut down by 24 seconds (CI -0:39 - -0:09; 10:03 ± 2:30 vs 10:27 ± 2:16, p = 0.003). Oxygen saturation was slightly lower at the end of the test with the mask. There was no significant difference in heart rate, or blood pressure during the test. Conclusion: Wearing a surgical mask causes a statistically significant decrease in exercise capacity and increase in perceived exertion. This small effect is not clinically significant for the interpretation of test results.