Microsporidiosis in pediatric renal transplant patients in Cape Town, South Africa: Two case reports

Abstract

Microsporidia are an emerging group of pathogens associated with life-threatening opportunistic infections in immunocompromised hosts, particularly human immunodeficiency virus (HIV)-infected individuals. There have, however, been recent reports of infection in adult solid organ transplant recipients. We report two cases in children, to our knowledge the first in the paediatric literature. Two 13-yr-old, HIV-seronegative females received deceased donor renal transplants from the same donor. Both patients suffered acute cell-mediated rejection and CMV infection reactivation, managed with intensified immunosuppression and ganciclovir. Pyrexia of unknown origin and intermittent diarrhea in both prompted extensive investigations. In both patients, numerous spores of a microsporidial species were demonstrated in renal tissue on biopsy and in the urine, using modified trichrome and quick-hot Gram-chromotrope staining. Electron microscopy and PCR confirmed Encephalitozoon cuniculi infections. Both patients were successfully treated with 400 mg twice daily of albendazole, with sustained clinical improvement. We recommend that microsporidiosis be considered in the differential diagnosis of pyrexia of unknown origin in severely immunocompromised pediatric solid organ transplant recipients, particularly when associated with diarrhea.

Confirmed microsporidial graft infection in a HIV‐negative renal transplant recipient: A case report and review of the literature

“…Microsporidia typically enter the host through the intestinal or respiratory tract with fecal‐oral transmission thought to be the primary mechanism . However, transmission from an infected donor has been described in solid organ transplant with one report of three different recipients being affected by microsporidia from a single common donor and another report of two pediatric renal transplant recipients from the same donor developing microsporidial infection . Protective immunity against E. cuniculi is primarily dependant on the cellular immune response and it seems that, in humans, infection requires simultaneous CD4 + and CD8 + T‐cell depletion .…”

“…Common coexisting infections were cytomegalovirus (in 5/9 cases) and urinary tract infection (in 3/9 cases). Other infections reported were brucellosis, BK viremia, tuberculosis clostridium difficile, aspergillous, and oral herpetic infection …”

“…Across the previously described cases, the commonly described biopsy features include tubulitis, tubular necrosis, granuloma formation, acute and/or chronic interstitial nephritis, and microsporidial spores. The glomeruli are usually spared …”

“…Microsporidia are obligate intracellular spore‐forming organisms, which have recently been reclassified from protozoa to fungi . They are primarily known to cause opportunistic infection in patients affected by human immunodeficiency virus (HIV); however, there have been several case reports of infection in recipients of solid organ and bone marrow transplants . We report a case of a non‐HIV–infected renal transplant patient with microsporidiosis of the renal tract causing acute deterioration in graft function.…”

Effector CD8 T cell immunity in microsporidial infection: a lone defense mechanism

“…To this day, the incidence of microsporidia in HIV patients remains elevated in places like Russia, Venezuela and Thailand, where microsporidia prevalence amongst AIDS patients can range from 13 to 80% [15–17]. Additionally, in the past two years, there have been increasing reports of microsporidiosis associated with solid organ transplant recipients [18–20]. Occurrence of microsporidiosis has also been reported in travelers, children and the elderly population [21–23].…”