Successful treatment of γ-heavy-chain disease with rituximab and fludarabine.

An 84-year-old Japanese man was admitted because of pancytopenia. The bone marrow was hypoplastic with a predominance of abnormal small lymphocytes and grape cells, which were positive for CD19 and CD20, and partially for the surface ĸ-light chain. Systemic CT scanning showed neither lymph node swelling nor hepatosplenomegaly. Serum immunoelectrophoresis and rocket immunoselection assays showed the presence of monoclonal IgG protein without a corresponding light chain and faint IgMĸ monoclonal protein. Histologic analysis of the clot preparation of the bone marrow aspirate facilitated a diagnosis of lymphoplasmacytic lymphoma (LPL). PCR analysis of the marrow cells demonstrated a clonal rearrangement of the immunoglobulin heavy-chain gene. From these results, we made a final diagnosis of γ-heavy-chain disease (γ-HCD) with underlying LPL localized in the bone marrow. We performed only a single course of immunochemotherapy (rituximab and fludarabine) in view of severely impaired hematopoiesis, which resulted in marked reduction of lymphoma cells and improvement of hematopoiesis. This report suggests the efficacy of rituximab plus fludarabine therapy for LPL-associated γ-HCD.

[Remnant lipoprotein cholesterol level measured by homogeneous assay reflects the quantity of intermediate-density lipoprotein].

Remnant lipoprotein can be measured by immunoseparation assay and polyacrylamide gel disc electrophoresis; however, these methods have some problems, such as a lack of specificity and being technically complicated. Recently, a new method, the remnant lipoprotein cholesterol homogeneous assay(RemL-C), has been established. In this study, we evaluated the basal performance of RemL-C assay. One hundred and fifty patients with diabetes mellitus were enrolled in this study. RemL-C level was higher in the midband (+) group than in the midband (-) group (p<0.01), and a strong correlation was observed between RemL-C level and remnant lipoprotein level measured by conventional method (r=0.89, p<0.01). RemL-C level correlated positively with triglyceride(TG) (r=0.94, p<0.01) and total cholesterol(TC) (r=0.39, p<0.01), negatively with high density lipoprotein(HDL-C) (r=-0.35, p<0.01) and positively with apolipoprotein (apo) CII, and apoE (apoCII: r=0.59, p<0.01, apoE: r=0.71, p<0.01). In particular, RemL-C level correlated strongly with TG and apoE. RemL-C level was significantly higher in patients with combined hyperlipidemia compared to patients with other hyperlipidemias (p<0.01). When the serum of a patient with combined hyperlipidemia was separated by sepharose 4B gel filtration, the fraction showing peak RemL-C level was observed between the fraction corresponding to VLDL and the fraction corresponding to LDL. Furthermore, the peak of RemL-C corresponded to the peak of apoE. Moreover RemL-C level correlated negatively with preheparin serum lipoprotein lipase mass that is a marker of metabolic syndrome (r=-0.30, p<0.01). These results suggest that the measurement of remnant lipoprotein by RemL-C assay reflects the quantity of intermediate-density lipoprotein. Since RemL-C measurement can be run on an automated clinical analyzer permitting quick and high throughput measurement, RemL-C levels may be useful in the screening of hyperlipidemia.