Abstract
A boy aged 4 years with nephrotic syndrome (NS) was referred to our hospital because of the third relapse of NS. Hypogammaglobulinemia associated with massive proteinuria was observed at the presentation. Residual urinary tract infection required intravenous piperacillin and immunoglobulin therapy (IVIG). Soon after IVIG, he complained of high fever with chills, bilateral knee joint pain, dry cough and chest discomfort. Although he did not develop renal insufficiency, a transient increase in the urinary β2-microglobulin and decrease in the serum complement hemolytic activity were observed. These clinical manifestations spontaneously ceased. A percutaneous renal biopsy for his NS performed 19 days after the episode of allergic rection revealed tubulointerstitial nephritis (TIN) with marked eosinophil infiltrates. Glomeruli showed minor glomerular abnormalities. Renal complications associated with IVIG treatment have been reported to date, however, acute TIN has rarely been seen.