The Frequency of ANA-positivity and Inflammatory Markers in COVID-19 "COVID-19 and ANA-positivity"

Background: Immune system activation plays an important role in pathogenesis and mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The inflammatory response during the disease is caused by the innate and adaptive immune systems.  Anti-nuclear antibody (ANA) positivity rate increases in SARS-CoV-2-positive patients due to adaptive immune system activation. This study aims to investigate the association between ANA-positivity rate and pulmonary symptoms, and inflammatory markers (C-reactive protein [CRP] and fibrinogen).

Material and Methods: One hundred five consecutive patients with the diagnosis of COVID-19 were included in this cross-sectional study. Participants were divided into groups according to the ANA and pulmonary symptom status. Clinical (gender, age) and biochemical (hemogram, liver function tests, kidney function tests, D-Dimer, CRP, and fibrinogen) were compared between the groups and the impact of ANA positivity on pulmonary symptoms development was assessed.

Results: Of the 105 patients, 60 of them had no pulmonary symptoms. The remaining 45 patients had at least one pulmonary symptom. ANA immunofluorescence assay (IFA) positivity rate was 19% (20/105 patients) in the study group. 60% of the ANA-positive patients were positive at 1/160, 30% at 1/320 and 10% at 1/1000 titer. ANA-IFA positivity rate was found higher among patients with pulmonary symptoms; however, the difference was not statistically significant (26.7% vs. 8/60 13.3%, respectively; p=.085). The CRP and fibrinogen levels were (6.9 vs. 3.4, p=.132, and 346.5 vs. 326, p=.183) among ANA positive and negative patients.  Twelve (63.2%) patients with ANA-positivity had pulmonary symptoms, and 33 (39.3%) patients with ANA-negativity had pulmonary symptoms (p=0.058).

Conclusions: Although there is no difference between patients with or without pulmonary symptoms, ANA, which may reflect the pathogenetic role of adaptive immune dysregulation, can often be detected in patients with Coronavirus disease 2019.