Mycobacterium avium-intracellulare-associated acute interstitial nephritis: a rare cause of renal allograft dysfunction

Mycobacteria in Organ Transplant Recipients

This review describes the epidemiology and risk factors of tuberculosis (TB) in solid organ transplant recipients. We discuss the pre-transplant screening for risk of TB and management of latent TB in this population. We also discuss the challenges of management of TB and other difficult to treat mycobacteria such as Mycobacterium abscessus and Mycobacterium avium complex. The drugs for the management of these infections include rifamycins which have significant drug interactions with immunosuppressants and must be monitored closely.

Interferon-gamma Release Assay-positive Granulomatous Interstitial Nephritis in a Patient with a History of Diffuse Large B Cell Lymphoma

Tuberculosis is a common etiology of granulomatous interstitial nephritis (GIN). However, the absence of evidence of lung involvement and lack of mycobacterial isolation in cultures make the etiological diagnosis and treatment decision challenging. We herein report a 46-year-old man with severe renal failure, a persistent fever, and a history of lymphoma. A renal biopsy exhibited GIN. Despite no evidence of tuberculosis except for a positive interferon-gamma release assay (IGRA), the patient was successfully treated with anti-tuberculosis drugs. Our case suggests that anti-tuberculosis therapy should be considered for patients with IGRA-positive GIN after excluding other etiologies.

A non-immunocompromised host with nontuberculous mycobacteria-associated tubulointerstitial nephritis

A 50-year-old man was admitted to our hospital with the complaints of fever and general malaise. He had no history of human immunodeficiency virus (HIV) infection or treatment with immunosuppressive agents. We performed renal biopsy to investigate possible acute kidney injury. Pathological findings showed inflammatory cell infiltration, including granulomatous lesions in the interstitium. We diagnosed the patient with acute granulomatous tubulointerstitial nephritis. We initiated prednisolone (PSL) 40 mg/day (0.6 mg/kg), in combination with isoniazid for a latent tuberculosis infection, because of positive results in interferon-γ release assays. The patient's fever and malaise promptly disappeared, and his renal function improved. After the patient had been discharged, Mycobacterium intracellulare grew in cultures of his renal tissue and urine. We gradually reduced the dose of PSL; we initiated combination therapy with ethambutol, clarithromycin, and rifampin. After 2 years of follow-up, the patient continued treatment for chronic kidney disease; it has since enabled him to avoid renal replacement therapy. This report describes a rare instance of nontuberculous mycobacteria-associated tubulointerstitial nephritis in a patient without a history of HIV infection or organ transplantation. In differential diagnosis of granulomatous tubulointerstitial nephritis, clinicians should consider drugs, sarcoidosis, tubulointerstitial nephritis and uveitis syndrome, vasculitis, and infections (e.g., involving mycobacteria). Prompt microbiological examinations, especially of urine or biopsy cultures, are vital for diagnosis.

Disseminated Nontuberculous Mycobacterium Presenting as Chronic Diarrhea and Wasting

Infections due to nontuberculous mycobacterium (NTM) are important in chronically immunosuppressed populations and are a particular threat to solid organ transplant recipients (SOT). However, they are not a common occurrence and have protean manifestations, making it important that clinicians maintain a high degree of suspicion in the correct patient population. Mycobacterium avium complex (MAC) usually presents with pulmonary involvement in immunocompetent population and disseminated disease in SOT patients with fever of unknown origin, lymphadenopathy, and cutaneous lesions being part of the well-known presentation. It is not commonly described as causing severe diarrhea. Here, we present an interesting case of a patient with a kidney and pancreas transplant who presented with debilitating wasting and chronic diarrhea. Biopsies and cultures confirmed MAC. To our knowledge, this is the first case report of MAC causing severe wasting diarrhea in renal transplant patients. The patient was treated with a multidrug regimen. Given the rare presentation of MAC presenting as chronic diarrhea, the treatment regimen is not standardized and infectious disease specialists should be involved early on. Up to 30% of renal transplant patients infected with NTM lose graft function and 20% die. Unfortunately, our patient suffered both these outcomes.

A rare case of disseminated Mycobacterium avium complex with colitis in a renal transplant recipient

Mycobacterium avium complex (MAC) colitis is a rare complication of immunosuppression in solid organ transplant (SOT) recipients. Here, we describe a case of disseminated MAC infection with colitis following renal transplantation. Despite common pathways of immunosuppression, SOT recipients and human immunodeficiency virus (HIV)-infected patients differ in their typical presentations of MAC infection. Intestinal infections have been more commonly reported in HIV-infected patients than in SOT recipients. The explanation for this difference may be related to HIV's targeted effects on the CD4⁺ T-cell reservoir in gut-associated lymphoid tissue.

Successful Diagnosis of Intestinal Mycobacterium avium Complex Infection in a Kidney Transplant Recipient Using Nasogastric Aspirate Culture: A Case Report

Intestinal Mycobacterium avium complex (MAC) infections are rare and can be challenging to diagnose. We describe a case of intestinal MAC infection in a kidney transplant recipient with 5 months of unexplained weight loss and abdominal pain who developed intestinal obstruction. Esophagoduodenoscopy with biopsies was performed but was nondiagnostic. Intestinal MAC was diagnosed via nasogastric aspirate culture results. The patient's symptoms rapidly improved after initiation of appropriate treatment, but he later died of aspiration pneumonia and candidemia.

Mycobacterial Infections in Solid Organ and Hematopoietic Stem Cell Transplantation

Mycobacterial infections are uncommon in solid organ and hematopoietic stem cell transplant recipients but carry significant morbidity and mortality. Donor screening strategies for tuberculosis should be emphasized in high-risk populations. Both tuberculosis and nontuberculous mycobacterial infections can have pulmonary and extrapulmonary manifestations of infections. Recommended treatment regimens typically involve multiple drugs with significant adverse effects and drug interactions.

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.