A case of chronic lymphocytic leukemia associated with nephrotic syndrome

The patient (a 56-year-old male) had no subjective symptoms, although mild proteinuria had been observed in 1986. He gradually started to notice bilateral pitting edema of the lower extremities, general fatigue, night sweating, and Raynaud's phenomenon in around August 1988. He visited a hospital with an episode of acute tonsillitis and a profound amount of proteinuria with nephrotic syndrome and serological abnormalities such as positive antinuclear antibody, high titer of anti-DNA antibody and hypocomplementemia were recognized. At that time, he was referred to our hospital for further detailed examinations. Renal biopsy revealed typical histopathological findings compatible with lupus nephritis, i.e. mesangial cell proliferation, IgG and C1q deposits on the glomerular capillary wall by immunofluorescence and electron-dense deposits on subepithelial lesions by electron microscopy. His white blood cell count was increased (16,000/mm³), with marked lymphocytosis (66%, absolute number of Ly: 10,560/mm³). The analysis of lymphocyte subpopulations showed that the majority of lymphocytes (53%) were surface Ig positive lymphocytes (i.e., B-cells) with monoclonality of IgM, IgD and ϰ light chain. The myelogram also showed an increased percentage of lymphocytes (48.6%) with the same surface marker. According to the criteria of the NCI-sponsored workshop (1988), CLL (Rai stage 0) was diagnosed. Proteinuria disappeared in response to prednisolone (40 mg/day) therapy, but there was the persistence of lymphocytosis. Thus, it is speculated that in this case autoimmune phenomena associated with CLL might have caused renal damage in morphology to that of lupus nephritis.