Karyomegalic interstitial nephritis with focal segmental glomerulosclerosis: A rare association
An 8-year-old male child presented with a history of facial puffiness and edema of one year duration. He was diagnosed to have nephrotic syndrome and was treated by a local physician with steroids. He did not improve, however, and was referred to this hospital for further management.\nThere was no family history of kidney disease. He is the first child of non-consanguineous marriage. There was no history of drug ingestion including exposure to mycotoxins or other herbal medicines. No history of recurrent respiratory symptoms. On examination, patient had stunted growth with moon facies, secondary to steroids and had clinical features of rickets.\nHis investigations revealed hemoglobin of 10 g/dl, blood urea 33 mg/dl and serum creatinine 0.7 mg/dl. His liver functions revealed hypoalbuminemia of 2.6 g/dl. His liver enzymes were within normal limits. He was human immunodeficiency virus non-reactive and hepatitis B surface antigen and hepatitis C virus and 24 h urine protein was 3565 mg/dl. Complete urine examination showed 2+ albumin, 4-6 red blood cells and granular casts. Ultrasound revealed normal sized kidneys with normal echotexture.\nHe was started on cyclophosphamide. However, there was no response even after 6 months. Hence a kidney biopsy was done. Biopsy showed 23 glomeruli, four of whom showed segmental sclerosis []. Basement membrane and cellularity were normal in the uninvolved glomeruli. Tubular epithelial cells revealed changes diffusely. The lining cells in many cells revealed enlarged nuclei with lobulated appearance. These cells are larger than the normal tubular epithelial cells []. There was chromatin clumping giving a hyperchromatic appearance. Mitoses were sparse. There is atrophy of the tubules with thickening of tubular basement membrane. There is interstitial fibrosis and interstitial mild lymphomononuclear infiltration [].\nImmunohistochemical stains for BK virus and cytomegalovirus were negative. Ki-67 index was low. Immunofluorescence did not reveal any significant immune deposits.\nHe is under regular follow-up and his last creatinine has increased to 1.2 mg/dl.