[Clinical evolution and levels of anti-S SARS-CoV-2 IgG in rheumatic disease and COVID-19].

Controversies still exist regarding the humoral response to the virus SARS-CoV-2 in convalescent patients and seroconversion in patients with autoimmune diseases. There are few reports on the clinical and evolution of COVID-19 in the latter group. The objective was to examine the clinical and evolutionary characteristics associated with COVID-19 and the percentage of seroconversion in people with rheumatic diseases. Fifty-three patients were included, mainly with rheumatoid arthritis and lupus. The majority were female and average age 48 ± 14 years. Symptoms: fever (56%), anosmia (35.8%), dyspnea (34%), headache (30.2%) and cough (30.2%). Duration of infection 12 ± 7 days. Almost half of the patients were hospitalized (23, 43.4%), 5 in critical care units (9.4%) and 3 died (5.6%). The prevalence of steroid use was 56.6% (30), with an average dose of 8 mg/d, and 17 (32%) used immunosuppressive biopharmaceuticals. There was a correlation between age and the need for hospitalization with a risk of 9.4% per year. There were no differences with other variables. The presence in serum of IgG immunoglobulin against SARS-CoV-2 protein S was determined in 23/53 patients (43.4%), with detectable levels in 15 (62.2%), and in the 23 without autoimmune connective tissue diseases who suffered from COVID-19, 12 had detectable antibodies. Death in this group of rheumatic diseases was low, similar to the general population. More than half had specific antibodies against the virus regardless of the medication used.