IgA monoclonal gammopathies are accompanied with higher serum TGF-β1 levels than IgG or IgM monoclonal gammopathies – screening study

Abstract

Abstract Background The progression of monoclonal gammopathies is affected by a range of factors, including the microenvironment surrounding plasma cells. It is recognized that TGF-β1 plays a distinct role in stimulating IgA production. Hence, this study aims to investigate whether individuals with serum IgA monoclonal immunoglobulins (paraproteins) exhibit elevated total TGF-β1 levels compared to those with IgG or IgM paraproteins. Method To achieve this goal, individuals with a positive laboratory findings of monoclonal gammopathy, were segregated according to the paraprotein class, as well as according to the type of the light chain. Total TGF-β1 levels were assessed in blood serum samples containing IgG (n = 50), IgM (n = 31), and IgA (n = 46) paraproteins. Results Elevated level of TGF-β1 was confirmed in sera with IgA paraproteins (median 25.8 ng/ml; interquartile range IQR: 19.0-33.7) compared to those having IgG (median: 18.2 ng/ml; IQR: 14.3–22.1; P < 0.001) or IgM paraproteins (21.5 ng/ml; IQR: 15.0-27.4; P = 0.043). Also, higher TGF-β1 level was detected in sera with IgMλ then those with IgMκ paraproteins (P = 0.043). Conclusions This research affirms the role of TGF-β1 in the pathophysiology of IgA monoclonal gammopathies and potential switch towards IgA isotype, known for less favorable prognosis.