Effect of beta 2-microglobulin on immunoglobulin production

Chronic renal failure patients display high serum levels of beta 2-microglobulin (beta 2-M) and a pronounced defect in immunoglobulin production. In this light, the present study was conducted to investigate whether beta 2-M might influence the rate of antibody synthesis. Peripheral blood mononuclear cells (PBMC) from healthy subjects were cultured in the presence of beta 2-M (80 mg/l) for 7 days. Immunoglobulin concentrations were measured by ELISA-techniques in culture supernatants. Basal IgM levels were 390 +/- 10 ng/ml and increased to 940 +/- 216 ng/ml in the presence of beta 2-M. After PWM stimulation, IgM concentrations were 2654 +/- 614 ng/ml without and 3750 +/- 914 ng/ml with beta 2-M. IgG and IgA production by PBMCs was not influenced by beta 2-M in the culture medium. Likewise, the generation of beta 2-M by PBMCs was unchanged in the presence of exogenous beta 2-M in the medium. In terms of clinical relevance, serum beta 2-M levels of 28 uremic patients were correlated with capacity of their PBMCs for immunoglobulin production in vitro. However, there was no apparent correlation between beta 2-M serum levels and immunoglobulin synthesis in vitro. Taken together, beta 2-M seems to have a stimulatory effect on IgM synthesis in vitro. Whether this has some clinical meaning in patients with chronic renal failure remains to be investigated.