Monoclonal gammopathy in COVID-19 pregnant patients

ABSTRACT

Monoclonal gammopathies (MG) are a group of disorders ranging from the benign to the malignant plasma cell dyscrasias to the lymphoproliferative disorders, typically characterized by the presence of a monoclonal component (MC) at serum protein electrophoresis (SPE). This condition has been also observed in association with a spectrum of acute and chronic inflammatory diseases, including viral infections. We selected for this study pregnant patients hospitalized from 2018 at the Department of Gynecology of the AOU Federico II of Naples (that include from March 2020 a section dedicated to pregnant patients with Sars-Cov2 infection), who presented a MC at the SPE (Capillarys 2, Sebia), at prenatal checks. Our population has involved 20 pregnant patients (average age of 35yo, from 22 to 47), 8 of which tested positive for COVID-19 by real-time reverse-transcriptase polymerase chain reaction of nasopharyngeal swabs. It should be considered that 3 patients came in the prepandemic period. The MC characterization revealed 7 patients with IgG k ranging from 1 to 10 g/L;5 with IgG k<3 g/L;1 with IgM k 7,7 g/L;5 with IgG k and IgG lambda<2 g/L;1 with 2 IgG lambda 6,7 g/L and 2,0 g/L;1 with 2 IgA k 9,6 g/L and 1,3 g/L. At hospitalization, 2 patients already had a diagnosis of MGUS, while for the others the MC presence was an occasional finding. It should be noted that 2 COVID-19 patients underwent therapy with casirivimab and imdevimab and one non COVID-19 patient to anti-D immunoprophylaxis after having already identified the MC. For 5 patients MC was detected during the second trimester and 4 of these had Sars-Cov2 infection;in the other 15 at the end of pregnancy. We observed that in the pregnant population, where in the pre COVID-19 era in our laboratory the MGUS percentage was of 0.3/year, the incidence increased to 0.6/year since February 2020. The presence of these MGUS must be investigated over time to understand the transience of the MC linked to viral infection. Previous studies hypothesized that the presence of MC during the inflammatory phase could reflect the degree of immune system hyperactivation in patients with severe COVID-19 disease. Further studies are needed to evaluate its frequency in pregnancy, longterm evolution, and prognostic role in this clinical setting.