CD40LG and Waldenstrom macroglobulinemia: However, some groups reserve the diagnosis of IgM MGUS for patients without immunophenotypic evidence of WM clonal B cell population [5], as was stated in the Second International Workshop on Waldenström Macroglobulinemia [6], whereas the diagnosis of asymptomatic WM (AWM) could be established in a patient without symptoms regardless of the percentage of BM infiltration and the amount of IgM.