CD40LG and monoclonal gammopathy: IgM was elevated (1,465 mg/dL), serum electrophoresis had a monoclonal band in the B2 region, serum immunofixation was positive for monoclonal gammopathy IgM Kappa, serum Kappa free light chain were elevated (578.9 mg/L), and urine immunofixation was positive for Bence Jones Kappa proteins.