Successful treatment of cryoglobulinemic glomerulonephritis derived from Waldenström's macroglobulinemia by rituximab-CHOP and tandem high-dose chemotherapy with autologous peripheral blood stem cell transplantation.

Waldenström's macroglobulinemia (WM) is a slowly progressive, low-grade B cell lymphoproliferative disorder. In contrast to the indolent progression, the development of cryoglobulinemic glomerulonephritis associated with WM is a rare, aggressive, and life-threatening complication. We describe the case of a 53-year-old man who suffered from WM, which was accompanied by cryoglobulinemic glomerulonephritis. WM was diagnosed on the basis of an increase in monoclonal IgM kappa and infiltration of abnormal lymphoplasmacytic cells in the bone marrow. Moreover, the case was complicated by increase in the levels of urinary protein, serum creatinine, and serum cryoglobulin. Histological findings showed endocapillary glomerulonephritis with hyaline plugs. Electron microscopy demonstrated the accumulation of electron-dense deposits in the subepithelial, subendothelial, intramembranous, and mesangial areas, which revealed cryoglobulinemic proliferative glomerulonephritis. The patient received four courses of rituximab therapy followed by four courses of R-CHOP therapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) in combination with cryofiltration. Subsequently, the patient underwent high-dose chemotherapy (melphalan [L-PAM]) followed by tandem autologous peripheral blood stem cell transplantation. After these treatments, the patient remained disease-free for 26 months. Histological findings of cryoglobulinemic glomerulonephritis were markedly improved after these treatments. Our case suggests that these treatments may be a feasible, safe, and effective strategy for critical cryoglobulinemic glomerulonephritis derived from WM.