Nontuberculous mycobacterial infections after transplantation: a diversity of pathogens and clinical syndromes

Disseminated Mycobacterium haemophilum infection in a renal transplant recipient

Opportunistic infections are a major concern in renal and transplant medicine. We present the case of a renal transplant recipient with a generalised Mycobacterium haemophilum infection after an increase in immunosuppressive therapy and treatment with a tumour necrosis factor-α (TNF-α) inhibitor. Infection involved skin and soft tissue, joints and bones, as well as the renal transplant with an interstitial nephritis. Rapid diagnosis using PCR and DNA sequencing allowed early appropriate treatment. Triple antibiotic therapy and reduction in immunosuppression resulted in a slow but sustained recovery. Immunosuppression causes severe opportunistic infections. TNF-α inhibitors are very effective and well tolerated but have an increased susceptibility to infections with mycobacteria. Mycobacterial infections represent a significant clinical risk to transplant recipients because of their aggressive clinical course and the need for complex toxic antibiotic treatments. In these patients, M. haemophilum is a cause of skin infections.

Non-tuberculous mycobacterial infections in solid organ transplant recipients: An update

Non-tuberculous mycobacteria are ubiquitous environmental organisms that are now increasingly recognized as important causes of clinical disease in solid organ transplant recipients. Risk factors of non-tuberculous mycobacteria infection are severe immunologic defects and structural abnormalities. Lung transplant recipients are at higher risk for non-tuberculous mycobacterial disease compared to recipients of other solid organs. The clinical presentation could be skin and soft tissue infection, osteoarticular disease, pleuropulmonary infection, bloodstream (including catheter-associated) infection, lymphadenitis, and disseminated or multi-organ disease. Management of non-tuberculous mycobacteria infection is complex due to the prolonged treatment course with multi-drug regimens that are anticipated to interact with immunosuppressive medications. This review article provides an update on infections due to non-tuberculous mycobacteria after solid organ transplantation, and discusses the epidemiology, risk factors, clinical presentation, and management.

Molecular methods for detection of invasive fungal infections and mycobacteria and their clinical significance in hematopoietic stem cell transplantation

Infection remains an important source of morbidity and mortality in patients who undergo hematopoietic stem cell transplantation (HSCT). In the immune reconstitution period after transplantation, HSCT recipients are most likely to have bacterial or fungal infections. Invasive fungal infections (IFIs) and mycobacterial infections (MBIs) are among the complications of HSCT, with high morbidity and mortality rates. Early diagnosis of both is crucial in order to manipulate the disease and to avoid fulminant outcomes. This chapter reviews the current knowledge on the molecular diagnosis of IFIs and MBIs in HSCT recipients, describing two different polymerase chain reaction (PCR)-based methods, one commercial (qPCR, Roche) and one in-house IS6110-based protocol.