Unusual Presentation of Disseminated Mycobacterium kansasii Infection in Renal Transplant Recipients and Rapid Diagnosis Using Plasma Microbial Cell-free DNA Next-generation Sequencing

Mycobacterium haemophilum diagnosed via Karius test in a heart transplant recipient: A case report

BACKGROUND

Mycobacterium haemophilum is a rare, slow-growing nontuberculous mycobacterium known to cause infections primarily in immunocompromised individuals. M. haemophilum infections typically present as skin and soft tissue infections; however, infections may progress to disseminated disease involving multiple organ systems. Diagnosing M. haemophilum infections can be challenging due to its slow growth in conventional culture methods and its resemblance to other mycobacterial species. As a result, it may be misidentified or overlooked, leading to delays in diagnosis and appropriate treatment. The prognosis of M. haemophilum infections can vary depending on factors such as the extent of the disease, the timeliness of diagnosis, and the patient's underlying health condition.

SUMMARY

In this case report, we provide a detailed clinical presentation, diagnostic workup, and treatment course of a heart transplant patient with M. haemophilum infection. Our patient presented with worsening generalized pain in multiple skin lesions. After extensive rheumatologic and infectious workup leading to nodule biopsies, the patient was diagnosed with M. haemophilum by Karius test and started on appropriate treatment.

CONCLUSION

Early recognition and appropriate treatment are essential for improving outcomes and reducing morbidity and mortality associated M. haemophilum. This case underscores the clinical utility of the Karius test in identifying unusual pathogens in a heart transplant patient with a complex medical history, emphasizing the role of next generation sequencing tests in aiding in earlier diagnosis to guide treatment and improve patient outcomes in challenging infectious disease cases.

Nontuberculous mycobacterial infections in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation

BACKGROUND

The incidence of mycobacterial infections in patients with hematologic malignancies and hematopoietic stem cell transplant (HSCT) recipients is increasing, contributing to significant mortality and morbidity. This review explores the epidemiology, risk factors, clinical presentation, diagnosis, and treatment of nontuberculous mycobacteria (NTM) in this population.

METHODS

A literature search was performed using PubMed with keywords and MeSH terms pertaining to the topics of nontuberculous mycobacteria, hematologic malignancies, hematopoietic stem cell transplant, cellular therapies, chimeric antigen therapies, epidemiology, diagnosis, and treatment. Additionally, we examined the reference lists of the included articles to identify other pertinent studies.

RESULTS

Diagnosing mycobacterial disease among patients with hematologic disease and treatment-associated immunosuppressive conditions is challenging due to the lack of distinctive clinical, radiographic, and laboratory markers, as well as the atypical manifestations compared to immunocompetent patients. Treatment involves using a combination of antibiotics for extended durations, coupled with strategies to achieve source control and reduce immunosuppression when feasible. This is complicated by the absence of clear data correlating in-vitro drug susceptibility and clinical outcome for many antimicrobials use to treat NTM, adverse drug-drug interactions, and the frequent challenges related to poor medication tolerability and toxicities.

CONCLUSION

The rising incidence and corresponding clinical challenges of mycobacterial infections in this unique patient population necessitate a heightened awareness and familiarity of NTM disease by clinicians to achieve timely diagnosis and favorable treatment outcomes.