2005 Volume 47 Issue 5 Pages 540-546
A 60-year-old man, who had been diagnosed as having paroxysmal nocturnal hemoglobinuria (PNH) in 1994, was admitted to our hospital with general fatigue, and dark urine after a common-cold in January 2001. In the peripheral blood, the red blood cell count was 136×104/μl, hemoglobin 4.0g/dl and hematocrit 12.4%. The serum creatinine level was 9.9mg/dl. Kidney biopsy revealed focal and segmental proliferation of mesangial cells, mesangial matrix expansion, acute tubular necrosis, interstitial fibrosis and hemosiderine deposits in the tubular epithelial cells confirmed by Berlin-blue staining. Immunofluorescence microscopy showed IgA and C3 deposition in the mesangium. Electron microscopy revealed electron dense deposits in the mesangial area and heavy electron dense hemosiderin pigments in proximal tubular epithelial cells. After the transfusion of six units of washed red blood cells and two sessions of hemodialysis, the renal function returned to the levels before admission.