Analysis of long-term antibody response in COVID-19 patients by symptoms grade, gender, age, BMI, and medication.

The first aim of the study was to analyze the change in antibody titer at 15-day intervals until 60 days postsymptom onset (PSO). The second aim was to analyze the relationship between antibody titer and symptom grade, gender, age, body mass index (BMI), medications, vitamin supplements, and herbal therapies. Blood samples were collected from 43 patients (5 mild, 21 moderate, 17 severe diseases), 18 women (41.9%), and 25 men (58.1%), on 15, 30, 45, and 60 days PSO after COVID-19 infection. The serum antibody titers were determined by measuring the COVID-19 immunoglobulin G (IgG) antibodies by enzyme-linked immunoassay (ELISA). Associations between the duration of symptoms, demographic and clinical parameters, medications and vitamins used, and herbal therapies were evaluated by interviewing the participants. Within the first 15 days of illness, 81.4% of the patients were positive. From Day 45 PSO, seropositivity was 89.5%. The anti-SARS-CoV-2 antibody titers were statistically higher in men than women at all times (p < 0.01). Antibody titer was higher in older participants compared to younger participants (p < 0.02). Plaquenil or favipiravir use did not affect antibody response (p > 0.05). Men had a higher fever (p = 0.006), shortness of breath (p = 0.004), and chest pain (p = 0.03) than women. We found powerful antibody response by 60 days PSO, as well as higher antibody response and severity of symptoms in the men gender. Data also showed that SARS-CoV-2 antibodies are higher in individuals with older age, whereas BMI, concomitant chronic disease, and medications had no effect on antibody titers.