De novo lupus nephritis in a renal transplanted child: a case report.

De novo lupus nephritis (LN) is a rare complication in renal transplantation recipients. We present the clinical manifestations of de novo LN in a 12-year-old boy who received a cadaveric renal transplant. The cause of end-stage renal disease was prune belly syndrome with renal dysplasia. His immunosuppressive drugs included tacrolimus, mycophenolate sodium, and prednisolone. After 3 years of treatment, he developed nephrotic syndrome (NS) without other symptoms of systemic lupus erythematosus (SLE). The renal pathology of the transplanted kidney showed suspicious acute cellular rejection and LN World Health Organization class IV-G (A/C). Antinuclear antibody was positive, but anti-dsDNA and anti-Smith were negative. The serum complements were initially normal. Pulse methylprednisolone was given and the dosages of all immunosuppressive drugs increased; notwithstanding, his edema and hypoalbuminemia worsened. Repeated biopsy of the transplanted kidney was done. A full-house pattern was documented under immunofluorescent examination which confirmed LN WHO class IV-G (A/C) without evidence of rejection. He then developed macrophage-associated hemophagocytic syndrome and cytomegalovirus pneumonia. He ultimately developed pulmonary hemorrhage and died owing to severe pneumonia. De novo LN should be considered in renal transplant recipients with new onset of NS despite there not being any other clinical manifestations of SLE.