Catastrophic antiphospholipid COVID-19 syndrome

Abstract

Thrombophilia, as well as multiple organ dysfunction, are typical manifestations of the severe new coronavirus infection that closely resemble the clinical signs of catastrophic antiphospholipid syndrome (CAPS). The objective: to assess whether catastrophic antiphospholipid syndrome is an essential manifestation of severe forms of COVID-19.Subjects and methods. 45 patients diagnosed with the new coronavirus infection (SARS-CoV-2) and a severe course of viral pneumonia (more than 3 points on the NEWS score by the admission, CT 3-4, oxygenation index below 100, the need for at least high-flow oxygen therapy). They were assessed for the development of CAPS due to signs of progressing organ dysfunction despite the ongoing intensive therapy, suspected pulmonary embolism and progressing venous thrombosis of a lower extremity or subclavian vein. It was an essential provision that they should have no signs of bacterial infection (blood procalcitonin should be below 0.5 μg/l). The antiphospholipid syndrome was diagnosed based on the detection of antibodies to β-2-glycoprotein in the blood (A/t β-2-GP1 IgGAM, A/t β-2-GP1 IgM, A/t β-2-GP1 IgG) and to cardiolipin (A/t CL IgM , A/t CL IgG) by ELISA tests. The course of the disease was monitored using other routine clinical (temperature, complete blood and urine counts) tests and blood panel tests reflecting the severity of the systemic inflammatory response (ferritin, CRP, interleukins 6 and 18), and the state of the hemostatic, respiratory, circulatory, liver and kidney systems.Results. Antiphospholipid antibodies (aAPL) moderately exceeding the reference values were detected in 9 out of 45 patients (20%), mainly due to IgA and IgM isotypes to β-2-glycoprotein and IgM isotype to cardiolipin. The assessment of the antibody titer in 5 patients over time (after 7 days) revealed a decrease, but it did not affect the outcome (four of them died). In 36 patients, some traces of aAPL were found that did not reach the lower limit of the norm, despite the uniformity of the clinical signs and similarity of biochemical parameters reflecting the severity of organ disorders. The absence of antibodies did not prevent the development of thrombotic complications (thrombosis of large vessels and pulmonary embolism in 5 patients). There were no other manifestations often associated with CAPS (thrombocytopenia, hemolytic anemia, decreased fibrinogen concentration in the blood). Conclusion. Catastrophic antiphospholipid syndrome is not inevitable in severe COVID-19 cases, however, it can develop as one of the manifestations of thrombophilia that occurs in such patients.