MYD88 (L265P) mutation is an independent risk factor for progression in patients with IgM monoclonal gammopathy of undetermined significance.

摘要

MYD88 (L265P) is a recurrent somatic mutation in Waldenstrom macroglobulinemia (WM).1"4 By means of allele-specific poly-merase chain reaction (AS-PCR), the MYD88 mutation is detectable in almost all patients with WM and in roughly half the patients with IgM monoclonal gammopathy of undetermined significance (IgM-MGUS).IgM-MGUS patients have a probability of progression to WM or to other lymphoproliferative disorders (LPD) of —1.5% per year, and the initial concentration of the serum monoclonal (M) protein is the main predictor of progression.In a case-control study of 77 IgM-MGUS patients, we previously demonstrated that the MYD88 mutation was associated with higher disease burden and with a higher risk of progression to WM or to other LPD.We have now analyzed by AS-PCR bone marrow samples, collected at the time of diagnosis, of 136 consecutive IgM-MGUS patients, with the aim to confirm the prognostic role of the MYD88 mutation in a longitudinal study and to evaluate the effect of the MYD88 mutation and of the other potential risk factors in multivariate analysis.