Abstract
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.
Footnotes
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Contributors MRD, JLW, WBB, MK, AM, SP, VT, DLF, and SLB conceptualized the project. JLW curated and created the models to analyze the data. MRD, JLW, and SLB obtained and interpreted the data. MRD, JLW, and SLB wrote the original draft. MRD, JLW, WBB, MK, AM, SP, VT, DLF, and SLB reviewed and edited the manuscript. MRD, JLW, and SLB visualized the data. JLW, WBB, and SLB supervised the project. WBB, AM, and SLB administered the project, and AM and MFK acquired funding to support the study. All authors contributed to critical revision and have approved the manuscript, contributed significantly to the work, and approved its submission to the Journal of Investigative Medicine. All authors agree to be accountable for all aspects of the work ensuring questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
Funding The research was supported, in part, by an award from Dialysis Clinic, Inc. (Project #C-3953).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement
Data are available upon reasonable request. The data analyzed in this article are available in the USRDS Database, at https://www.usrds.org/for-researchers/simple-data-requests/, and can be accessed by submitting a Simple Data Request form.
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