Case Quiz (May 2019)

A 7-year-old boy was presented with the complaints of decreased urine output, generalized edema and fever since 9 days. He had no history of similar episodes in the past or history suggestive of chronic kidney disease in the family. There was no history of diarrhea, sore throat, rash or hematuria preceding this illness. Examination revealed generalized edema, eyelids puffiness and pallor. Patient did not have rash, joint involvement or purpura. Blood pressure was normal. He had abdominal distension due to ascites. Liver was tender and palpable 5 cm below the costal margin with a span of 11 cm. Spleen was not palpable.

Investigations on admission, revealed hemoglobin level of 5.2 g/dL, reticulocyte count of 3%, leukocyte count of 12,200/cu mm with 67% neutrophils, 25% lymphocytes and platelets 1,42,000/cu mm. Peripheral smear showed microcytosis, anisocytosis, schistocytes, few tear drop and target cells. Blood level of albumin was 3.1 g/dL, total proteins 5.6 g/dL, pH 7.4, pCO 2 26 mm Hg and bicarbonate 16.1 mEq/L, creatinine 1.6 mg /dL, urea nitrogen 75 mg/dL, sodium 136 mEq/L and potassium 5.6 mEq/L. Antistreptolysin O (ASO) was negative, C3 was 28 mg/dL and hepatitis B and C serology were negative. Urinalysis showed 3+ proteinuria, 10-15 red cells /hpf and 5-10 leukocytes/hpf. Prothrombin time was 17 seconds (control 19 seconds) and aPTT was 27 seconds. Lactate dehydrogenase and D-dimer were normal. Serum C4 was normal and antinuclear antibodies anti-ds, DNA were negative.

There was a steady increase in blood urea, creatinine and potassium with a fall in urine output over the next two days. Peritoneal dialysis was done for 72 hours following which these levels normalized and the urine output improved.

Renal biopsy was done.

One month later, he was admitted with fever, vomiting, diarrhea and abdominal pain and 4+ proteinuria. He rapidly developed septicemia with hypotension and multiorgan failure, and died after four days of intensive care and ventilator support.

Case Answer (May 2019)

     HUS with membranoproliferative GN (MPGN). HUS could be secondary to MPGN. Recent reports implicate the role of factor H which is an important component of the alternate complement pathway in both HUS as well as MPGN

Mutations in the factor H gene are associated with severe and diverse diseases including the rare renal disorders of HUS and MPGN, and and the more frequent age related macular degeneration.

Treatment options include control of hypertension, plasma infusions or plasmapheresis and use of steroids