Cryptococcosis in a transplanted kidney allograft.

A 32-year-old man with chronic kidney disease secondary to obstructive nephropathy was referred for deceased donor renal transplant, with 9 hours of cold ischemia. The donor was a 53-year-old man who died due to acute ischemic stroke and had a creatinine level of 1.1mg/dL, was cytomegalovirus IgG+ and IgM+, had 5 mismatches, and negative serology for other infections. The recipient was given thymoglobulin, and immunosuppression was maintained using tacrolimus, prednisone, and everolimus. Initially, the patient exhibited delayed graft function and was treated with methylprednisolone from 11th to 13th day, because of suspected cellular acute rejection. On the 20th day, a graft biopsy (Figure 1) revealed acute tubular necrosis and Cryptococcus sp. infection. On the 27th day, his creatinine levels increased because of amphotericin B nephrotoxicity; therefore, amphotericin B was replaced with fluconazole. However, the kidney function worsened, accompanied by severe anemia and increased levels of lactate dehydrogenase. Thus, tacrolimus was interrupted under suspicion of hemolytic uremic syndrome. Another biopsy examination revealed results similar to the fi rst biopsy, without signs of thrombotic microangiopathy. The patient developed fever and pneumonia. Amphotericin B and cefepime FIGURE 1 Renal allograft biopsy. A. Multiple structures of grouped yeasts with Periodic acidSchiff (PAS) staining, besides the glomeruli (PAS 400x). B. Tubule-interstitial granulomatous infl ammatory infi ltrate (see arrows) involving yeast structures with single budding dewdrop-like (PAS 400X). C. Detail of: Celled yeast prominent capsule composed mostly of polysaccharides (HE 1,000X). D. Moderate infl ammatory infi ltrate tubule-interstitial involving yeast structures (see arrows) of the renal tissue in focal areas in renal parenchyma (Jones Stain 200x).