Transient biclonal gammopathy after SARS-CoV-2 infection. A case report: Reporte de un caso

Abstract

Patients infected by SARS-CoV-2 present a variable clinical course, from asymptomatic or mild respiratory symptoms to a severe evolution with a major inflammatory and immune reaction. The appearance of a monoclonal component as a manifestation of this inflammatory and immune state is poorly described. We present the case of a 74-year-old male patient, who began in 2020 with anemic syndrome, livedo reticularis and acrocyanosis triggered by cold and relieved by heat. The laboratory showed hemolytic anemia due to cold antibodies and its complementary study was compatible with cold agglutinin disease. He was treated with rituximab without response, subsequently receiving rituximab-bendamustine, resolving symptoms, decreasing cold agglutinin titer, improving anemia and normalizing biochemical profile. In February 2022, he presented multifocal pneumonia due to SARS-CoV-2, requiring hospitalization for 19 days, with minimal reactivation of his underlying disease. At this stage, two monoclonal components IgG kappa and IgG lambda are detected in electrophoresis and immunofixation in serum, added to their IgM kappa known for cold agglutinin disease. The follow-up shows that these components remain detectable for 4 months, a subsequent control shows the persistence of only IgM kappa in immunofixation, with the disappearance of the new components. The electrophoresis is also negative. Usually viral infections generate polyclonal hypergammaglobulinemias, in contrast we show how in this case the SARS-CoV-2 infection is associated with transient biclonal gammopathy, which we propose as a manifestation of the intense immune reaction generated by the virus.