A 53-year-old white woman with end-stage renal disease received a kidney transplant and was maintained on an immunosuppressive regimen. Three months later she had a fever (38.3degC) and was found to have acute renal failure. Renal transplant biopsy was performed. Periodic acid-Schiff staining of a biopsy section showed yeast cells and hyphae. The most likely diagnosis for this patient is infection with
Immunosuppressive agents have reduced the incidence of rejection of transplanted solid organs but have increased risk of opportunistic infection. Fungal infections, while not the majority of infections in these patients, carry a high risk of mortality. Candida and Aspergillus are responsible for most of these opportunistic infections that can occur within a month or after several months. A. fumigatus (most common species) infections are primary pulmonary infections that may be a rapidly necrotizing pneumonia with a potential to disseminate. The organism is a mold in the environment and in the host. The hyphae are septate with acute angle, dichotomous, branching. Candida infections generally start as candidemia, which may reach the blood stream by catheters or translocation from the gut. C. albicans is the most frequent Candida isolate. This component of normal flora is generally in the yeast form as a commensal and when infection occurs the additional presence of hyphae and pseudo-hyphae is observed. C. glabrata, which is seen with increasing frequency, does not form hyphae. Cryptococcus neoformans is an encapsulated yeast. Other fungi have been reported with less frequency.
Aspergillus fumigatus
Candida albicans
Candida glabrata
Cryptococcus neoformans
Mycology