SARS‐CoV‐2 infection is not associated with the emergence of monoclonal gammopathies

Abstract

AbstractBackgroundUpon infection activated plasma cells produce large quantities of antibodies which can lead to the emergence of a monoclonal component (MC), detectable by serum protein electrophoresis (SPEP). This study aims to investigate any correlation between SARS‐CoV‐2 infection and MC development and, if identified, whether it persists during follow‐up.MethodsSPEPs of 786 patients admitted to hospitals between March 01 2020 and March 31 2022 were evaluated. Positive (SARS‐CoV‐2+) and negative (SARS‐CoV‐2−) patients to nasopharyngeal swab for SARS‐CoV‐2 by RT‐PCR were included. The persistence/new occurrence of MC was investigated for all patients during follow‐up. Patient groups were compared by chi‐square analysis.ResultsMC was identified in 12% of all patients admitted to hospital, of which 28.7% were SARS‐CoV‐2+. The most common immunoglobulin isotype in both groups was IgG‐k. There was no correlation between MC development and SARS‐CoV‐2 infection (p = 0.173). Furthermore, the risk of MC persistence in SARS‐CoV‐2‐negative patients was revealed to be higher than in the SARS‐CoV‐2+ at follow‐up (HR = 0.591, p = 0.05).ConclusionsOur study suggests that the detection of MC during SARS‐CoV‐2 infection is most likely due to the hyperstimulation of the humoral immune system, as also occurs in other viral infections.