Abstract: PO2218
Disseminated Mycobacterium Avium Complex in a Renal Transplant Patient with Subsequent Immune Reconstitution Inflammatory Syndrome Post Transplant Nephrectomy
Session Information
- Transplantation: Clinical - Noninvasive Biomarkers, Immune Regulation, and Fascinomas
November 04, 2021 | Location: On-Demand, Virtual Only
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 1902 Transplantation: Clinical
Authors
- Middleton, William George, Toowoomba Health Service, Toowoomba, Queensland, Australia
- Govindarajulu, Sridevi, Toowoomba Health Service, Toowoomba, Queensland, Australia
Introduction
Mycobacterium avium Complex (MAC) are a group of pathogenic mycobacteria present in soil and water. Infection can present with respiratory symptoms, but in immunocompromised patients disseminated disease with fevers, weight-loss or diarrhoea is more common.
Immune Reconstitution Inflammatory Syndrome (IRIS) is an excessive but protective inflammatory response against an existing pathogen when immune function is restored. It is usually seen in patients with Human Immunodeficiency Virus but has been described in renal transplant patients with MAC infection. It can lead to hypercalcaemia via increased macrophage 1α-hydroxylase activity, causing increased 1,25(OH)2D3 production.
Case Description
A 54-year-old male presented 3 years post renal transplant with recurrent fevers, night sweats and pancytopenia with a haemoglobin of 76 g/L, leucocytes of 1x109/L and platelets of 72x109/L. He was on Tacrolimus, Mycophenolate and Prednisolone, and was previously treated with anti-thymocyte globulin for cellular rejection. Bone marrow and blood cultures were positive for MAC at 8 weeks. He was started on clarithromycin, ethambutol and rifampicin, with reduction in immunosuppression. Blood cultures were negative 1 month post anti-MAC therapy.
He represented 7 months later with fevers and 22lb weight loss. Extensive bloodwork was negative. Computerised Tomography showed cervical lymphadenopathy and mesenteric stranding. Non-necrotising granulomas were demonstrated on fine needle aspirate of both a cervical lymph node and bone marrow, in keeping with disseminated MAC. Transplant nephrectomy was performed to allow cessation of immunosuppression. Renal histology showed granulomatous interstitial nephritis.
He had ongoing fevers and hypercalcaemia for 1 month post nephrectomy with albumin corrected calcium of 3.32 μmol/L. Septic screen was negative. He was treated with oral prednisolone for suspected IRIS with resolution of symptoms.
Discussion
Disseminated MAC is a rare but life-threatening infection in renal transplant recipients that can require nephrectomy for cessation of immunosuppression.
Non-tuberculous mycobacteria can take 6 weeks to culture and require specific culture media.
Differentiation of IRIS vs drug resistance as a cause of persistent fevers is important.