Clinical characteristics and outcome of immunoglobulin M-related disorders.

We analyzed the clinical features and prognostic factors for transformation of immunoglobulin Mrelated disorders (IgM-RDs) to malignant lymphoproliferative disease (MLD) in 83 patients with IgM-RDs. We studied 19 patients with type I cryoglobulinemias, 56 patients with type II cryoglobulinemias, 5 patients with peripheral neuropathies (PNs), and 3 patients with idiopathic thrombocytopenic purpuras. Fourteen patients with cryoglobulinemias presented with mild to moderate hepatomegaly with or without splenomegaly. Fourteen patients with type II cryoglobulinemias had arthralgias and/or vascular purpura (12 receiving corticosteroids), and 7 presented with PN. These latter patients and those with PNs without cryoglobulinemia were treated with steroids, cyclophosphamide, or polychemotherapy with/without plasma-exchange. Cumulative probability of evolution to MLD at 5 years was 15% (95% CI; 5%-25%). At a median of 62 months (12-195 months), 8 cases of IgM-RDs (8.4%) evolved to overt Waldenstrom's macroglobulinemia (n = 6), 1 case to non-Hodgkin's lymphoma, and 1 case to B-cell chronic lymphocytic leukemia. At univariate analysis, male sex (P = 0.02), IgM level > or = 3 g/dL (P < 0.0001), detectable Bence Jones proteinuria (P = 0.0005), lymphocytosis (P = 0.049), and high erythrocyte sedimentation rate (P = 0.003) significantly correlated with the evolution risk. Age, blood cell counts, b2-microglobulin level, degree of marrow lymphoplasmacytic infiltration, type of cryoglobulinemia, and hepatitis C virus positivity did not correlate with transformation. Although IgM-RDs represent a distinct clinical entity frequently requiring treatment in view of the IgM-related symptoms, their evolution probability and prognostic factors for malignant transformation seem to widely overlap those described for asymptomatic IgM monoclonal gammopathies.

Prognostic factors for transformation in asymptomatic immunoglobulin m monoclonal gammopathies.

We evaluated the risk of transformation of asymptomatic immunoglobulin (Ig) M monoclonal gammopathy (aIgM-MG) into symptomatic lymphoproliferative disease in 384 patients, in subgroups of patients with IgM MG of undetermined significance (MGUS) and smoldering Waldenstrom's macroglobulinemia (sWM). One hundred seventy-two patients with aIgM-MG with bone marrow (BM) histopathology and immunophenotyping were available for analysis. After a median of 45 months (range, 12-233 months), 45 cases of aIgM-MG (11.7%) evolved into lymphoproliferative disease, as follows: symptomatic WM (n = 41), non-Hodgkin's lymphoma (NHL; n = 2), IgM multiple myeloma (IgM-MM; n = 1), and primary amyloidosis (n = 1). Cumulative transformation probability at 5 and 10 years was 8% and 29%, respectively. The parameters significantly correlated with evolution were, at univariate analysis, BM lymphoplasmacytic infiltration, high erythrocyte sedimentation rate, hemoglobin (Hb) level, IgM size, and peripheral lymphocytosis; at multivariate analysis, the parameters were IgM size and peripheral lymphocytosis, with Hb level associated with a trend toward higher progression risk. Of the 138 cases of IgM-MGUS, 14 (10.1%) evolved (13 WM, 1 IgM-MM) after a median of 75 months (range, 12-117 months); of the 34 cases of sWM, 13 (38.2%) progressed to WM after 55 months (range, 13-154 months). In patients with IgM-MGUS, event-free survival at 5 and 10 years was 95% and 83%, respectively, and in patients with sWM, 77% and 42%, respectively (P = 0.0001). Among patients with aIgM-MG, those at high risk of evolution are patients with sWM, a distinct entity with clear BM evidence of NHL.