Antiphospholipid antibodies in patients hospitalized with COVID-19 infection in conventional units

This study aimed to evaluate the status of antiphospholipid antibodies (APL) in hospitalized patients with COVID-19 infection. This case-control study was conducted at Shahid Beheshti Hospital of Hamadan University of Medical Sciences from 2020 to 2022. Participants were divided into two groups: COVID-19 (n=35 recovered cases) and non-COVID-19 (n=34). The study assessed anti-cardiolipin antibodies (ACA) including IgM, IgG, and antibodies against β2-glycoprotein (anti-B2GPI). Additionally, the lupus anticoagulant (LAC) test was conducted on patients not using anticoagulant medications. Enzyme-linked immunosorbent assay (ELISA) was employed for ACA and anti-B2GPI testing, while the LAC test was conducted using a fully automated coagulometer. The mean LAC among participants was 33.8 ± 7.53s for females and 36.39 ± 5.54s for males. Results of antibody tests indicated that ACA IgM was positive in 2 out of 33 cases, with none in the non-recovered COVID-19 and COVID-19 patients (P value = 0.15). Furthermore, the LAC test showed positive results in 5 and 2 patients in the case and control groups, respectively (P value = 0.26). Correlation analyses of LAC with other antibodies revealed no significant associations for non-COVID-19 patients, while a significant association was observed between LAC and β2GPI IgG and ACA IgG (r = 0.52; P <0.001 and r = 0.51; P <0.001, respectively). Negative correlations were found between LAC and ACA IgM and hospitalization in the case group (r = -0.22 and r = -0.04, respectively). For the control group, negative correlations were observed between LAC and β2GPI IgM, ACA IgG, and ACA IgM (r = -0.25, r = -0.03, and r = -0.03, respectively). Additionally, Anti-β2GPI IgG and anti-β2GPI IgM tests were positive in both COVID-19 and non-COVID-19 groups (two positives in total) (P value = 0.98 vs P value = 0.31). We recommend routine testing for aPL antibodies in recovered COVID-19 patients to assess their normal condition. Our findings suggest that APS antibodies in COVID-19 patients can serve as a negative prognostic indicator, guiding decisions on the need for intensive care based on antibody levels.