A 20-year-old man presented with elevated serum creatinine level 3 months after kidney transplantation. Cytomegalovirus (CMV) pp65 antigen was detected by indirect immunofluorescent method. Figure A shows contaminated cells in phosphorous green (× 400). Kidney needle biopsy was performed and tubulointerstitial nephritis with CMV cytopathic effects was observed on pathologic examination. No obvi...

Multiple myeloma is uncommon in individuals younger than 40 years. Renal involvement is common in this disease, but acute tubulointerstitial nephritis is very rare. In 20% of patients, only the light chain is produced and serum protein electrophoresis is normal; however, in urine protein electrophoresis of these patients, the M spike is present. We reported a case of multiple myeloma in a 39-ye...