Mucormycosis (zygomycosis) of renal allograft

Incidence and risk factors for mucormycosis in renal transplant patients

BACKGROUND

Renal transplant patients are at increased risk for mucormycosis. Diabetes, neutropenia, deferoxamine therapy, and immunosuppressive medications have been associated with increased risk of mucormycosis in studies of solid organ transplant recipients. To focus on renal transplant patients, the US Renal Data System (USRDS) was queried to determine the incidence and risk factors for mucormycosis.

METHODS

All renal transplant patients in the USRDS from 1988 to 2015 were queried for a diagnosis of mucormycosis after the first transplant date using ICD-9 and ICD-10 codes. The International Classification of Diseases (ICD) codes, which currently exist in the ninth and tenth revisions, are a global system of classification used to code diagnoses, procedures, and symptoms. We defined proven mucormycosis by a histopathologic or fungal stain procedure code within 7 days of the diagnosis code. Logistic regression controlling for person-years at risk was used to examine demographic and clinical diagnosis risk factors for mucormycosis.

RESULTS

Of the 306,482 renal transplant patients, 222 (0.07%) had codes consistent with proven mucormycosis. The incidence of mucormycosis increased from 1990 to 2000 (peak 17.6 per 100,000 person-years) and subsequently demonstrated more variability. Hispanic ethnicity (OR=1.45), age 65 years or greater (OR=1.64), other or black race compared with white race (OR=1.96 and 1.74), cadaver or other donor type (OR=2.41), and receiving tacrolimus (OR=2.09) were associated with increased risk. Comorbidities associated with decreased risk of mucormycosis included female sex (OR=0.68), iron overload (OR=0.56), and receiving mycophenolate mofetil (OR=0.67) or azathioprine (OR=0.53).

CONCLUSIONS

In renal transplant patients, age, deceased donor graft transplant, tacrolimus administration, race other than white, and Hispanic ethnicity were associated with increased risk of mucormycosis. Unexpectedly, iron overload was protective. Mucormycosis is a rare infection in renal transplant patients which should be considered in patients with the above risk factors after more common infections have been ruled out.

Donor-derived renal allograft mucormycosis in a combined liver and kidney transplantation: Case report and review of the literature

Mucormycosis infrequently may present with isolated renal involvement. Among solid organ transplant recipients, renal allograft mucormycosis has been most often associated with medical tourism or transplantation outside of the western world. We report a case of an HIV/HCV co-infected woman who underwent simultaneous liver and kidney transplantation with a Public Health Service increased risk donor organ. 16 days after transplant, she developed massive hematuria and was found to have renal allograft Rhizopus spp. involvement, we surmise to have been from donor-derived infection. Therapy included nephrectomy, debridement, liposomal amphotericin B, and posaconazole with survival. We reviewed PubMed indexed, English-language cases of isolated renal mucormycosis in general, in HIV/AIDS, and from donor-derived renal allograft infections.

Isolated Renal Mucormycosis in Immunocompetent Hosts: Clinical Spectrum and Management Approach

Isolated renal mucormycosis in immunocompetent hosts is a rare entity. We present the largest case series of isolated renal mucormycosis in immunocompetent hosts. Retrospective data of isolated renal mucormycosis from March 2012 to June 2017 was reviewed. Fifteen patients of isolated renal mucormycosis were identified. Contrast-enhanced computed tomography scan showed enlarged globular kidneys with decreased or patchy enhancement, perinephric stranding and thickened Gerota's fascia in all patients. Ten patients with unilateral involvement underwent nephrectomy and two of four patients with bilateral renal mucormycosis underwent bilateral nephrectomy. Two patients were managed with intravenous antifungal therapy alone. Overall, the mortality rate in our series was 40% (6/15). Isolated renal mucormycosis in healthy immunocompetent hosts is an emerging new entity. Prompt diagnosis based on the characteristic clinical and radiological picture and starting high-dose antifungal therapy at least 24 hours before surgical debridement offer the best chance of survival in these patients.