Clinical Course of Intestinal Microsporidiosis in Renal Transplant Recipients.

Abstract

Clinical course and therapeutic options of intestinal microsporidiosis (IM) in renal transplant recipients are poorly documented. This retrospective monocentric study included all patients admitted between 2007 and 2013 for IM due to Enterocytozoon bieneusi, diagnosed by quantitative stool PCR. Patients were treated either by fumagillin 60mg/d for 14 days and tapering of immunosuppression (n=13) or merely by tapering of immunosuppression (n=9). Mean age at diagnosis was 48±13 years. A sequential quadritherapy with antithymocyte globulin induction was used in 64% of patients. Eight patients (36%) had a history of acute rejection. At diagnosis, mean CD4-cell count was 417±405/mm3 and gammaglobulin level was 7.9±2.8g/L and 5 (23%) had experienced an opportunistic infection. IM occurred 52±55 months after kidney transplantation. The symptoms always associated diarrhea (6.5±4.3 stools/d) and a weight loss of 8±4% of total body weight - similar whatever the treatment - sometimes abdominal pain (27%) or fever (9%). Clinical recovery occurred after a mean delay of 38±53 days after diagnosis. Seventeen patients (67%) exhibited acute renal failure (AKI classification), including 4 at stage 3. Estimated glomerular filtration rate (eGFR, MDRD formula) decreased by 4.7±10.9ml/min/1.73m2 three months after IM and 4.9±14.3ml/min/1.73m2 at last follow up, 19±13months after IM. Two patients with stage 4 chronic kidney disease before IM required definitive initiation of hemodialysis 194 and 347 days after IM. In 5 fumagillin treated-patients (38%), therapy duration was shortened because of thrombopenia adverse event. Compared to untreated patients, those receiving fumagillin recovered faster (23±22 versus 63±79days after diagnosis) and showed a smaller decrease in eGFR 3 months after IM diagnosis (-1.4±10.2; [-19; +14]) versus -9.4±10.6; [-21; +10]) ml/min/1.73m2), although this difference was not significant. There was no rejection or death following IM. Acute renal failure is a frequent and severe complication in kidney transplant recipients with IM, with an incomplete recovery after resolution of diarrhea. Patients with pre-existing severe graft dysfunction may evolve to end-stage renal disease. Tapering immunosuppression might be sufficient for resolution of diarrhea, however adding fumagillin could help to fasten clinical recovery and to improve renal prognosis.