An 84-year-old woman had a 3-year history of hypertension, a femoral neck fracture 1 year previously, and a left radial fracture 1 month previously. She had no family history of renal disease or dialysis. She was noted to have renal dysfunction of unknown etiology 1 year prior to admission. She visited a regional clinic for edema and was observed to have renal dysfunction [serum creatinine (Cr), 2.7 mg/dL] and anemia 2 months prior to admission. Since that time, she had developed marked edema and progressive renal dysfunction (serum Cr, 3.7 mg/dL) and was referred to our hospital for further evaluation and treatment. On physical examination, her temperature was 37.1C, and her blood pressure was 168/63 mmHg. She showed marked abdominal distention due to ascites and also had lower extremity edema without dyspnea. Chest radiography revealed cardiac enlargement and bilateral pleural effusions, and an abdominal computed tomography (CT) scan revealed massive ascites and bilateral kidney enlargement (Fig. 1). The following laboratory results were obtained: white blood cell (WBC) count, 5,400 WBC/mm3; red blood cells (RBC) count, 250x104 RBC/mm3; hemoglobin (Hb), 8.2 g/dL; hematocrit (Ht), 24.0%; platelet count (plt), 15.8x104 plt/mm3; total protein (TP), 5.6 g/dL; albumin (Alb), 2.8 g/dL; blood urea nitrogen (BUN), 45 mg/dL; serum Cr; 3.9 mg/dL; sodium (Na), 140 mEq/L; potassium (K), 3.2 mEq/L; chloride (Cl), 104 mEq/L; C-reactive protein (CRP), 0.5 mg/dL; plasma glucose, 142 mg/dL; hemoglobin A1c (HbA1c), 4.8%; aspartate aminotransferase (AST), 38 IU/L; alanine aminotransferase (ALT), 18 IU/L; alkaline phosphatase (ALP), 787 IU/L; gamma glutamyl transpeptidase (gammaGT), 239 IU/L; IgG, 828 mg/dL; IgM, 700 mg/dL; and IgA, 148 mg/dL. Cryoglobulin was negative and an immunoglobulin (Ig) M (kappa) spike was identified on immunoelectrophoresis. The third complement component (C3) level was 59 mg/dL (normal 50-130 mg/dL); the fourth component (C4) level was 10.5 mg/dL (normal 10-50 mg/dL); hemolytic complement activity via the classical pathway (CH50) was 13 U/mL (normal 25.0-48.0 U/mL); and antinuclear antibody (ANA) was negative. Myeloperoxidase antibodies (MPO), proteinase 3 antibodies (PR3), antineutrophil cytoplasmic antibodies (ANCA), and anti-glomerular basement membrane (anti-GBM) antibodies were not detected. A urinalysis showed 1.17 g protein/g creatinine and 30-49 RBC/high-power field (HPF). The urinary beta-2 microglobulin (beta-2MG) level was 25,150 ng/mL. Bence Jones protein was negative in the urine. A bone marrow aspirate clot showed hypercellular bone marrow with 3% plasma cells.
At the time of hospitalization, a percutaneous kidney biopsy was not performed because of the patient's massive ascites. A percutaneous kidney biopsy was performed 1 month later after several paracentesis procedures, allowing the patient to lie in a prone position.
Histological findings revealed tubular dilatation, primarily involving the distal tubules, with extensive fibrosis in the interstitium, consistent with nephronophthisis-medullary cystic disease complex(NPH-MCKD). There were no remarkable glomerular changes except for global sclerosis consistent with the patient's age (Fig. 2). Immune deposits of IgG, IgA, IgM, C1q, C3, and fibrinogen were absent, despite the IgM kappa M protein detected in the serum. Electron microscopy revealed irregularities, thinning and disintegration of the tubular basement membrane (TBM). However, it was difficult to explain the patient's massive ascites and rapidly progressive renal dysfunction according to the histological findings.
Considering her advanced age (84 years of age) and symptomatic relief after paracentesis, no further investigation was done and she was discharged with a serum Cr level of 5.1 mg/dL 2 months after admission. She began hemodialysis therapy 1 month after discharge.