CASE 4
Ian S.D. Roberts, M.D.
Department of Cellular Pathology
John Radcliffe Hospital, Oxford, UK
CLINICAL HISTORY
A 44-year-old man presented with acute-on-chronic renal failure. In his past medical history, he had developed alcohol-induced chronic pancreatitis, for which he had undergone a subtotal pancreatectomy 14 years prior to the current admission. Following pancreatectomy, he developed insulin-dependent diabetes mellitus and malabsorption with diarrhoea and steatorrhea. He was poorly compliant with his pancreatic supplements.
Three years prior to this admission, diabetic retinopathy was diagnosed and he was found to be proteinuric. One year later he had mild renal impairment, serum creatinine 1.7 mg/dL (150 micromol/L) with proteinuria of 0.1 g/dL. Ultrasound showed normal sized kidneys (12 cm in length) and no evidence of obstruction. He had abnormal liver function tests (albumin 38 g/L, gammaGT 80 iu/L, bilirubin 9 micromol/L, AST 221 iu/L, alkaline phosphatase 330 iu/L). Liver biopsy at that time showed mild fibrous expansion of portal tracts but no bridging fibrosis or inflammation and no specific features of alcoholic liver disease.
His renal function remained stable over the following 18 months; serum creatinine was 2.0 mg/dL (178 micromol/L) five months before this admission. However, at that time he developed an osteomyelitis of the right big toe, treated with intravenous antibiotics followed by 3 months of oral antibiotics. His renal function deteriorated rapidly; serum creatinine had risen to 3.8 mg/dL (333 micromol/L) three weeks prior to admission and 11.7 mg/dL (1034 micromol/L) on admission.
On admission, he gave a one-week history of intermittent chest tightness and breathlessness related to exertion. He had also suffered some indigestion for 3 weeks but no vomiting or diarrhoea. He had no abdominal pain or urinary symptoms and reported a good, unchanged, urine output. He had been off antibiotics for six weeks and off alcohol for four months. He was on treatment with enalapril, bumetanide and insulin.
On examination he was cachectic, mildly dehydrated and had mild pitting shin oedema. Examination was otherwise unremarkable; he was apyrexial and had a pulse of 86 bpm and blood pressure of 121/57. Urine dipstick demonstrated protein ++, blood ++, glucose +. Initial blood tests were: haemoglobin 7.9 g/dL, MCV 97, WBC 11.35 x10 9 /L, platelets 258 x10 9 /L, blood pH 7.11, pCO 2 3.02 KPa, PO 2 8.2 KPa, bicarbonate 7.3 mmol/L, base excess –22.3 mmol/L, sodium 137 mmol/L, potassium 4.5 mmol/L, calcium 1.38 mmol/L, phosphate 3.82 mmol/L, glucose 14.9 mmol/L. Serum electrophoresis was normal, ANCA and anti-GBM antibodies were negative. Urine and blood cultures were negative. Renal ultrasound showed an 11.8 cm right kidney and 12.5 cm left kidney. There was no hydronephrosis or cortical scarring apparent. He was given haemodialysis and blood transfusion. In view of the rapid deterioration in renal function of unknown cause, a diagnostic renal biopsy was performed.
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