Post-infectious glomerulonephritis following infective endocarditis: Amenable to immunosuppression
An 11-year-old boy, a known case of acyanotic heart disease since infancy, was admitted with high-grade fever for 15 days. He had cough, respiratory distress, and chest pain for 1 day. On examination, he was conscious but sick looking and had pallor. His pulse rate was 140/min, with all peripheral pulses well palpable. His respiratory rate was 76/min and he had subcostal and intercostal recessions. The blood pressure was 102/60 mmHg. On examination of the chest, the child had bilateral fine crepts. The cardiovascular examination was suggestive of cardiomegaly. A grade 3/6 systolic murmur was heard all along the left sternal border. The second heart sound was loud and palpable. The liver was palpable 5.0 cm below the costal margin and the spleen was palpable 3 cm below the costal margin. A provisional diagnosis of congestive heart failure with a possibility of IE was made.\nThe investigations revealed a hemoglobin concentration of 5.6 g/dL with a microcytic and hypochromic picture. The total leucocyte count was 18,650 (polymorphs 70, lymphocytes 25, eosinophils 2, monocytes 2) and the platelet count was 102,000/mm3. All the three blood cultures sent were sterile. A chest X-ray showed cardiomegaly with congested lung fields. An urgent echocardiogram revealed an atrial septal defect (7 mm) and a restrictive perimembranous ventricular septal defect (5 mm) with multiple vegetations in the right ventricle at the site of impingement of jet and near the ventricular septal defect. A urine examination revealed 2+ proteinuria and 15-20 RBCs/hpf (40% dysmorphic). The kidney function tests showed urea of 64 mg/dl and creatinine of 0.8 mg/dl. A fundus examination revealed bilateral Roth’s spots. A diagnosis of IE with congestive heart failure was made. The child was started on furosemide and intravenous ceftriaxone, vancomycin, and gentamicin. The child received packed cell transfusion. After 5 days his renal functions worsened (urea 58 mg/dl and creatinine 1.7 mg/dl). The antibiotics were changed to piperacillin-tazobactam, teicoplanin and gentamicin in view of renal dysfunction and persistence of fever. Subsequently, the antibiotics were upgraded to meropenem and teicoplanin in view of non-response. The child received antibiotics for a total duration of 6 weeks. The fever subsided but the patient developed periorbital puffiness and his proteinuria increased to 3+ and renal functions continued to be deranged (urea 114 mg/dl, creatinine 1.2 mg/dl). The urinalysis after 6 weeks of antibiotic therapy showed 2+ proteinuria, 18-20 RBC/hpf and 20-25 casts/hpf (both fine and course).\nA renal biopsy done at this time showed moderate degree of chronic parenchymal damage in the form of tubular atrophy and interstitial fibrosis on Masson’s Trichrome stain []. There were 19 glomeruli, of which four were globally sclerosed. The viable glomeruli showed increase in mesangial matrix and cellularity with focal endocapillary proliferation [ and ]. Two glomeruli showed partial cellular to fibrocellular crescents [-]. The basement membrane was unremarkable on silver methenamine stain.\nImmunofluorescence showed fine granular deposition of C3, C1q and IgM in the glomerular capillary walls and mesangium []. Two crescents were positive for fibrinogen stain. A diagnosis of a receding phase of immune complex-mediated proliferative glomerulonephritis with crescents was made.\nThe anti-nuclear antibody was negative and antistreptolysin (ASLO) titers were normal, and C3 complement levels were 117 mg/dl. The serology for hepatitis B surface antigen and anti-HCV were negative. The child continued to have protienuria and also developed edema, while his heart failure was controlled. His total serum proteins were 6.0 g/dl and he had a serum albumin level of 2.8 g/dl. His cholesterol was 190 mg/dl. In view of persistent proteinuria, the child was started on oral prednisolone 2 mg/kg/day for 4 weeks. The child continued to have proteinuria and edema persisted. In view of a proliferative glomerulonephritis on renal biopsy, oral cyclophosphamide was added in doses of 2 mg/kg/day for 8 weeks with alternate-day steroids. At the end of treatment, the child became edema free. His urine protein was negative and his kidney functions had normalized (urea 27 mg/dl and creatinine 0.8 mg/dl). The child has been on follow-up for the last 1.5 years, and has continued to be well. He is off all medications at present.