A 59-year-old woman diagnosed with acute myeloid leukemia received successfully an allogeneic hematopoietic stem cell transplantation from an HLA-compatible unrelated donor following a reduced-intensity conditioning. The GvHD prophylaxis regimen was mycophenolate mofetil and cyclosporine. In the post-transplantation phase, the patient presented several complications, such as reactivation of CMV disease (CMV serostatus: D+, R+). Foscarnet was initiated and phosphonoformate crystalluria (proven by infrared spectrometry) was observed 7 days after onset of therapy associated with renal tubular epithelial cells in urine sediment. No hematuria was observed. The patient developed AKI KDIGO stage 1 24 days after foscarnet initiation.
A 71-year-old woman diagnosed with acute myeloid leukemia underwent, while in complete remission, a nonmyeloablative allogeneic hematopoietic stem cell transplantation with HLA-compatible unrelated donor. Conditioning regimen consisted in fludarabine and total body irradiation; graft-versus-host disease (GvHD) prophylaxis consisted of mycophenolate mofetil and ciclosporine. Following transplantation, the patient presented multiple complications such as a reactivation of CMV disease (CMV serostatus: D−, R+). Ganciclovir was administered without effect on the viral load of CMV. Hence, based on in vitro documentation of resistance of CMV to ganciclovir, the patient was switched to foscarnet. Phosphonoformate crystalluria (proven by infrared spectrometry) was observed 14 days after the onset of foscarnet therapy and associated with a nonglomerular hematuria and renal tubular epithelial cells in urine sediment. Progressive elevation of serum creatinine concentration occurred (AKI Kidney Disease: Improving Global Outcomes [KDIGO] stage 3), despite adaptation of foscarnet doses to kidney function. The patient died after probable fungal bronchopneumonia and septicemia while still on foscarnet.