Nontuberculous mycobacterial bloodstream infections after allogeneic hematopoietic stem cell transplantation

Disseminated Mycobacterium kansasii infection due to surgical site infection following allogeneic hematopoietic stem cell transplantation: A case report and literature review

This report details a rare case of surgical site infection (SSI) caused by Mycobacterium kansasii following allogeneic hematopoietic stem cell transplantation (allo-HSCT) in a 53-year-old patient with IgA-κ type multiple myeloma. After undergoing multiple chemotherapy regimens and two stem cell transplants, the patient developed an SSI 31 months post-transplantation, manifesting as an intracranial abscess at the site of a previous craniotomy. M. kansasii was isolated from the drainage fluid, marking this instance as a unique case in the literature of NTM infection post-allo-HSCT with such a delayed onset. The patient's treatment included targeted antimicrobial therapy based on susceptibility testing, resulting in eventual resolution of the infection, although the patient later succumbed to multiple myeloma relapse. This case underscores the critical need to consider NTM infections in the differential diagnosis of persistent fevers and SSIs in immunocompromised patients, particularly those with chronic graft-versus-host disease. It highlights the importance of early diagnostic and therapeutic interventions to manage these infections effectively. This report contributes to the limited but growing body of literature on NTM infections post-allo-HSCT and emphasizes the need for vigilance in monitoring postoperative patients, especially those with prolonged immunosuppression.

Prevalence and Characteristics of Non-tuberculous Mycobacteria (NTM) Infection in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation: a Systematic Review and Meta-analysis

PURPOSE

Non-tuberculous mycobacteria (NTM) infections in hematopoietic stem cell transplantation (HSCT) recipients represent a diagnostic and therapeutic challenge. Here, we aimed to review and analyze current literature on incidence, clinical presentation, and outcome of NTM infection after allogeneic HSCT.

METHODS

We performed a systematic review and meta-analysis of available literature regarding NTM infection in children and adults receiving allogeneic HSCT.

RESULTS

We identified 56 articles eligible for the analysis. Among 15 studies, describing 15,798 allogeneic HSCT, we estimated a prevalence of 1.26% (95% CI 0.72, 1.93) of NTM after transplant. Analysis of 175 patients with NTM infection showed a median time of diagnosis of 318 days after HSCT, an increased prevalence in adults (82.9%), and a most frequent pulmonary involvement (44%). Comparison between children and adults revealed an earlier post-transplant disease onset (median 130 days vs 287 days) and most frequent non-pulmonary presentation in children. A vast heterogeneity of therapeutic approach reflected the lack of universal recommendations regarding drug combination and duration of therapy. Overall, NTM-related mortality accounted for 33% in this systematic review.

CONCLUSION

Although rare, NTM infections can complicate post-transplant course with a high mortality rate in children and adults. The lack of prospective studies and guidelines prevents identification of risk factors and therapeutic recommendations.

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.

Catheter-related bloodstream Mycobacterium wolinskyi infection in an umbilical cord blood transplant recipient: a case report

Background

Catheter-related bloodstream infection (CRBSI), caused by rapidly growing mycobacteria (RGM), is a rare infectious complication in hematopoietic stem cell transplant (HSCT) recipients and can often be misdiagnosed as Gram-positive rod (GPR) bacteremia.

Case presentation

We present a case of CRBSI caused by Mycobacterium wolinskyi, a rare RGM, in a 44-year-old female patient who received an umbilical cord blood transplant.

Conclusions

Rapidly growing mycobacteria can stain as GPRs and may grow in routine blood culture media after 3–4 days of incubation. These features are not widely known to clinicians, and acid-fast staining is therefore recommended when unidentifiable GPRs are detected in blood cultures, especially in immunocompromised patients, such as those with hematologic malignancies or intravascular devices.

A Disseminated Mycobacterium Abscessus Infection in a Patient Affected by Pulmonary Graft versus Host Disease: Case Report with a Revision of Literature

Mycobacterium abscessus complex, hereinafter Mab, is a taxonomic group of rapidly growing, nontuberculous mycobacteria (NTM). Despite major advances in understanding virulence, pathogenicity and mechanism of antibiotic resistance, Mab remains a significant cause of pulmonary and extra-pulmonary disease. Herein, we describe a disseminated, macrolide-resistant, Mab subspecies abscessus infection occurring in a severely immune-compromised 34-year-old allotransplanted female patient affected by pulmonary chronic graft versus host disease (cGVHD). The infection was characterized by hematogenous spread, and besides lungs, it involved skin, and soft tissues, resulting in a highly debilitating, painful, and finally fatal disease. Our case describes the severe impact of Mab infections in the setting of allogeneic hematopoietic stem cells transplant (alloHSCT) and related complications. It also highlights the unmet need of preventive and surveillance measures together with the urgency of developing effective vaccines and drugs against emerging NTM. The scarce literature regarding Mab infections in alloHSCT patients is also reviewed.

Bloodstream infections with rapidly growing nontuberculous mycobacteria

Background

Bloodstream infections (BSI) with rapidly growing mycobacteria (RGM) resulted in recent nosocomial outbreaks predominantly in immunocompromised patients. A little is known about the clinical implications of RGM BSI with different species.

Methods

We conducted a multicenter retrospective cohort study of patients with RGM BSI from November 2011 to December 2020. Demographic data, clinical presentation, laboratory and radiographic findings and microbiological characteristics were used to tabulate descriptive statistics. We performed a comparative analysis of patients with BSI due to Mycobacterium abscessus complex (MABC) vs. other RGM.

Results

We identified 32 patients with positive blood cultures for RGM, 4/32 (12.5%) were considered to have unclear significance. The most common source for RGM BSI was intravascular catheters (14/28, 50%). Compared to other sources, patients with catheter-related bloodstream infection (CRBSI) received a shorter course of antimicrobial therapy (median [IQR]: one month [0.37–2.25] vs. six months [2–12]), (P = 0.01). The most common species isolated were MABC (12/28, 42.9%), followed by Mycobacterium fortuitum group (6/28, 21.4%) and Mycobacterium chelonae (6/28, 21.4%). Compared to other RGM, MABC BSI was more likely to be secondary to skin and soft tissue infection, associated with longer hospital stay (P = 0.04) and higher death rates despite a higher number of antimicrobial agents used for empirical and directed therapy per patient.

Conclusion

MABC BSI is associated with an overall more resistant profile, longer hospital stay, and higher death rate despite a more aggressive therapy approach.