Infections Caused by Mycobacterium tuberculosis in Recipients of Hematopoietic Stem Cell Transplantation

Changes in tuberculosis risk after transplantation in the setting of decreased community tuberculosis incidence: a national population-based study, 2008-2020

BACKGROUND

Transplant recipients are immunocompromised and vulnerable to developing tuberculosis. However, active tuberculosis incidence is rapidly declining in South Korea, but the trend of tuberculosis infection among transplant recipients has not been elucidated. This study aimed to evaluate the risk of active tuberculosis after transplantation, including risk factors for tuberculosis and standardized incidence ratios, compared with that in the general population.

METHODS

This retrospective study was conducted based on the South Korean health insurance review and assessment database among those who underwent transplantation (62,484 recipients) between 2008 and 2020. Tuberculosis incidence was compared in recipients treated during higher- (2010-2012) and lower-disease burden (2016-2018) periods. Standardized incidence ratios were analyzed using the Korean Tuberculosis Surveillance System. The primary outcome was the number of new tuberculosis cases after transplantation.

RESULTS

Of 57,103 recipients analyzed, the overall cumulative incidence rate 1 year after transplantation was 0.8% (95% confidence interval [CI]: 0.7-0.8), significantly higher in the higher-burden period than in the lower-burden period (1.7% vs. 1.0% 3 years after transplantation, P < 0.001). Individuals who underwent allogeneic hematopoietic stem cell transplantation had the highest tuberculosis incidence, followed by those who underwent solid organ transplantation and autologous hematopoietic stem cell transplantation (P < 0.001). The overall standardized incidence ratio was 3.9 (95% CI 3.7-4.2) and was the highest in children aged 0-19 years, at 9.0 (95% CI 5.7-13.5). Male sex, older age, tuberculosis history, liver transplantation, and allogeneic hematopoietic stem cell transplantation were risk factors for tuberculosis.

CONCLUSIONS

Transplant recipients are vulnerable to developing tuberculosis, possibly influenced by their immunocompromised status, solid organ transplant type, age, and community prevalence of tuberculosis. Tuberculosis prevalence by country, transplant type, and age should be considered to establish an appropriate tuberculosis prevention strategy for high-risk groups.

Evaluation of pulmonary abnormalities in recipients of hematopoietic cell transplants and cellular therapies

Hematopoietic cell transplant (HCT) and chimeric antigen receptor T-cell (CAR-T) therapy recipients are susceptible to multiple pulmonary complications that are caused by infectious and noninfectious processes. Numerous variables can be associated with specific pulmonary diseases including time from transplantation, presence of graft versus host disease (GVHD), underlying disease, and prolonged neutropenia and lymphocytopenia. Most pulmonary complications are infectious in origin, with bacterial pneumonia remaining the most common pulmonary infection, particularly before neutrophil engraftment. Invasive fungal infections continue to affect this patient population even when antifungal prophylaxis is used. Noninfectious pulmonary complications include a wide differential of pathologies in this population, and as clinical presentations of these various pulmonary disorders often overlap, clinicians frequently will use a multidisciplinary approach in diagnosing these abnormalities. Radiography, particularly with chest computed tomography (CT) imaging, is an essential tool in identifying pulmonary pathology and potential sources. While standard microbiological cultures of respiratory specimens are still utilized, their role is limited by low sensitivity and diagnostic yield. The likelihood of obtaining a diagnosis can be improved by using other microbiological assays, including fungal antigen tests and molecular diagnostic methods, particularly if specimens are collected via bronchoscopy. This review will highlight the more common causes of pulmonary diseases encountered after HCT and CAR-T and will examine the different methods in their diagnosis.

Haploidentical Stem Cell Transplantation Using Post-Transplant Cyclophosphamide for T-Cell Prolymphocytic Leukemia after Alemtuzumab Induction Therapy: A Case Report

T-cell prolymphocytic leukemia (T-PLL) is a rare aggressive disease with a poor prognosis. Allogeneic stem cell transplantation (allo-SCT) followed by alemtuzumab administration is the most promising treatment for T-PLL but is associated with a high risk of infections as alemtuzumab strongly suppresses cellular immunity, leading to high transplant-related mortality and unsatisfactory survival rates. In addition, for patients without human leukocyte antigen-matched donors, haploidentical stem cell transplantation (haplo-SCT) using post-transplant cyclophosphamide (PTCy) has been used because of the ready availability of donors and achievement of results comparable to those of transplantation with human leukocyte antigen-matched donors. However, there are no reports on the efficacy and safety, including infectious complications, of haplo-SCT with PTCy after alemtuzumab therapy in patients with. Here, we describe a 66-year-old Japanese male patient with T-PLL treated successfully with haplo-SCT after induction therapy of alemtuzumab for T-PLL. Approximately 3 months after the achievement of complete remission with alemtuzumab for T-PLL, haplo-SCT with reduced-intensity conditioning and PTCy was performed. Infectious complications were improved by early therapeutic interventions, and peripheral T cell counts gradually recovered. The patient was alive for more than 16 months after allo-SCT with no signs of relapse. Thus, haplo-SCT using PTCy should be considered as an option after alemtuzumab treatment for T-PLL.

Tuberculosis in Pediatric Solid Organ and Hematopoietic Stem Cell Recipients

Children undergoing solid organ and hematopoietic stem cell transplantation are at high risk of morbidity and mortality from tuberculosis (TB) disease in the post-transplant period. Treatment of TB infection and disease in the post-transplant setting is complicated by immunosuppression and drug interactions. There are limited data that address the unique challenges for the management of TB in the pediatric transplant population. This review presents the current understanding of the epidemiology, clinical presentation, diagnosis, management, and prevention for pediatric transplant recipients with TB infection and disease. Further studies are needed to improve diagnosis of TB and optimize treatment outcomes for these patients.

Study of clinical characteristics, risk factors and outcomes for tuberculosis post allogeneic stem cell transplant: never count it out

BACKGROUND

Allogeneic stem cell transplant (AlloSCT) recipients remain at a higher risk of developing tuberculosis (TB), especially in endemic populations. We conducted a retrospective study to identify the incidence, clinical presentation, and risk factors for active TB among our alloSCT recipients.

METHODS

Records of all patients transplanted between 1 January 2012 and 31 July 2020 were reviewed. Patients were followed up for outcome until 30 September 2020. None of the patients received prophylactic anti-tubercular drugs. Proven diagnosis of active TB was considered if Mycobacterium tuberculosis (MTB) was cultured from clinical samples or acid-fast bacilli (AFB) or MTB demonstrated on Ziehl-Neelsen (ZN) staining or histopathology or XPERT MTB, while probable diagnosis of TB was considered if histopathology findings were suggestive of caseation necrosis/epithelioid cell granulomas without any evidence of malignancy or lymphocyte rich exudative effusions (pleural/pericardial) without an alternative cause.

RESULTS

Among 381 alloSCT recipients, 15 patients (3.9%) developed TB at median of 246 (74-279) days post AlloSCT, after being symptomatic for a median of 22 (7-60) days, amounting to a cumulative incidence of 4.9%. All patients were started on four-drug anti tubercular therapy, ATT [Rifampicin, Isoniazid, Ethambutol, Pyrazinamide (RHEZ)], of which five patients developed hepatotoxicity at a median of 12 days after start of ATT, leading to drug modification. At last follow up, TB was cured in 13 (86.67%) patients, one succumbed to disease relapse, while others are still on treatment. Age ⩾ 30 years, immunosuppression for graft versus host disease (GvHD) > 6 months, prior use of tyrosine kinase inhibitors (TKI) and chronic GvHD on univariate analysis and immunosuppression for GvHD > 6 months on multivariate analysis were found to be associated with development of TB.

CONCLUSION

A high index of suspicion with timely workup and treatment of TB is the key in AlloSCT recipients, especially in endemic TB populations.

Infectious complications after hematopoietic stem cell transplantation: current status and future perspectives in Korea

Hematopoietic stem cell transplantation (HSCT) is a treatment for hematologic malignancies, immune deficiencies, or genetic diseases, ect. Recently, the number of HSCTs performed in Korea has increased and the outcomes have improved. However, infectious complications account for most of the morbidity and mortality after HSCT. Post-HSCT infectious complications are usually classified according to the time after HSCT: pre-engraftment, immediate post-engraftment, and late post-engraftment period. In addition, the types and risk factors of infectious complications differ according to the stem cell source, donor type, conditioning intensity, region, prophylaxis strategy, and comorbidities, such as graft-versushost disease and invasive fungal infection. In this review, we summarize infectious complications after HSCT, focusing on the Korean perspectives.

Tuberculosis and Transplantation

Mycobacterium tuberculosis is a major opportunistic pathogen in transplant recipients. Compared to that in the general population, the frequency of tuberculosis (TB) is 10 to 40 times higher in hematopoietic stem cell transplant (HSCT) recipients and 20 to 74 times higher in solid-organ transplant (SOT) recipients. Transplant recipients with TB are also more likely to develop disseminated disease, have longer time to definitive diagnosis, require more invasive diagnostic procedures, and experience greater anti-TB treatment-related toxicity than the general population. Specific risk factors for TB in SOT recipients include previous exposure to M. tuberculosis (positive tuberculin skin tests and/or residual TB lesions in pretransplant chest X ray) and the intensity of immunosuppression (use of antilymphocyte antibodies, type of basal immunosuppression, and intensification of immunosuppressive therapy for allograft rejection). Risk factors in HSCT recipients are allogeneic transplantation from an unrelated donor; chronic graft-versus-host disease treated with corticosteroids; unrelated or mismatched allograft; pretransplant conditioning using total body irradiation, busulfan, or cyclophosphamide; and type and stage of primary hematological disorder. Transplant recipients with evidence of prior exposure to M. tuberculosis should receive treatment appropriate for latent TB infection. Optimal management of active TB disease is particularly challenging due to significant drug interactions between the anti-TB agents and the immunosuppressive therapy. In this chapter, we address the epidemiology, clinical presentation, diagnostic considerations, and management strategies for TB in SOT and HSCT recipients.

Prevalence and risk factors of latent tuberculosis infection in Africa: a systematic review and meta-analysis protocol

INTRODUCTION

Latent tuberculosis infection (LTBI) remains a major public health problem and one of the major contributors to the pool of active tuberculosis cases. The true burden of LTBI in Africa is not known. Early modelling studies estimate that over 33% of the world's population is infected with latent tuberculosis. We propose conducting a systematic review and a meta-analysis to evaluate the burden and risk factors of LTBI in Africa reported in studies from 2000 to 2017.

METHODS AND ANALYSIS

We will include cross-sectional studies, cohort studies and case-control studies estimating either tuberculin skin test (TST) or interferon-gamma release assay (IGRA) confirmed prevalence of LTBI and associated risk factors among people in African countries. A comprehensive search of relevant literature will be conducted on electronic databases using common and medical subject heading (MeSH) terms for LTBI, and an African search filter. Risk of bias will be evaluated by assessing all qualifying full-text articles for quality and eligibility using a quality score assessment tool. Standardised data extraction will be carried out after which prevalence estimates will be pooled using random-effects models in Stata V.13. Where there is sufficient data , subgroup meta-analyses will be conducted by risk factors including participant's age group, occupation, location and HIV status. This systematic review will be reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses Protocols 2015 Statement.

ETHICS AND DISSEMINATION

No ethical issues were foreseen given that this was a protocol for a systematic review of published studies. The results of this study will be published in a peer-reviewed journal and presented at conferences.

TRIAL REGISTRATION NUMBER

Systematic review registration: PROSPERO CRD42016037997.

The demanding attention of tuberculosis in allogeneic hematopoietic stem cell transplantation recipients: High incidence compared with general population

BACKGROUND

The risk of developing tuberculosis (TB) in allogeneic hematopoietic stem cell transplantation (HSCT) recipients is expected to be relatively high in an intermediate TB burden country. This single-center retrospective study was conducted to investigate risk factors and the incidence of TB after allogeneic HSCT.

METHODS

From January 2004 to March 2011, 845 adult patients were enrolled. Starting April 2009, patients were given isoniazid (INH) prophylaxis based on interferon-γ release assay results. The incidence of TB was analyzed before and after April 2009, and compared it with that of the general population in Korea.

RESULTS

TB was diagnosed in 21 (2.49%) of the 845 allogeneic HSCT patients. The median time to the development of TB was 386 days after transplantation (range, 49-886). Compared with the general population, the standardized incidence ratio of TB was 9.10 (95% CI; 5.59-14.79). Extensive chronic graft-versus-host disease (GVHD) was associated with the development of TB (P = 0.003). Acute GVHD, conditioning regimen with total body irradiation and conditioning intensity were not significantly related. INH prophylaxis did not reduce the incidence of TB (P = 0.548). Among 21 TB patients, one patient had INH prophylaxis.

CONCLUSION

Allogeneic HSCT recipients especially those who suffer from extensive chronic GVHD are at a high risk of developing TB. INH prophylaxis did not statistically change the incidence of TB, however, further well-designed prospective studies are needed.

Mycobacteria

The immunocompromised host is at increased risk of Mycobacterium tuberculosis complex and nontuberculous mycobacteria infection. Although Mycobacterium tuberculosis complex is a significant mycobacterial pathogen, nontuberculous mycobacteria causes substantial disease in those with suppressed immune responses. Mycobacterial infections can cause significant morbidity and mortality in this patient population, and rapid identification and susceptibility testing of the mycobacterial species is paramount to patient management and outcomes. Mycobacterial diagnostics has undergone some significant advances in the last two decades with immunodiagnostics (interferon gamma release assay), microscopy (light-emitting diode), culture (automated broth-based systems), identification (direct PCR, sequencing and matrix-assisted laser-desorption ionization–time of flight mass spectrometry) and susceptibility testing (molecular detection of drug resistance from direct specimens or positive cultures). Employing the most rapid and sensitive methods in the mycobacterial laboratory will have a tremendous impact on patient care and, in the case of Mycobacterium tuberculosis complex, in the control of tuberculosis.

Autologous Hematopoietic Stem Cell Transplantation-10 Years of Data From a Developing Country

Intensive chemotherapy followed by autologous stem cell transplantation is the treatment of choice for patients with hematological malignancies. The objective of the present study was to evaluate the outcomes of patients with mainly lymphoma and multiple myeloma after autologous stem cell transplant. The pretransplant workup consisted of the complete blood count, an evaluation of the liver, kidney, lung, and infectious profile, chest radiographs, and a dental review. For lymphoma, all patients who achieved at least a 25% reduction in the disease after salvage therapy were included in the study. Mobilization was done with cyclophosphamide, followed by granulocyte colony-stimulating factor, 300 µg twice daily. The conditioning regimens included BEAM (carmustine, etoposide, cytarabine, melphalan) and high-dose melphalan. A total of 206 transplants were performed from April 2004 to December 2014. Of these, 137 were allogeneic transplants and 69 were autologous. Of the patients receiving an autologous transplant, 49 were male and 20 were female. Of the 69 patients, 26 underwent transplantation for Hodgkin's lymphoma, 23 for non-Hodgkin's lymphoma, and 15 for multiple myeloma and 4 and 1 for Ewing's sarcoma and neuroblastoma, respectively. The median age ± SD was 34 ± 13.1 years (range, 4-64). A mean of 4.7 × 10⁸ ± 1.7 mononuclear cells per kilogram were infused. The median time to white blood cell recovery was 18.2 ± 5.34 days. Transplant-related mortality occurred in 10 patients. After a median follow-up period of 104 months, the overall survival rate was 86%. High-dose chemotherapy, followed by autologous stem cell transplant, is an effective treatment option for patients with hematological malignancies, allowing further consolidation of response.

Lymph node tuberculosis after allogeneic haematopoietic stem cell transplantation: an atypical presentation of an uncommon complication

Mycobacterium tuberculosis infections are uncommon complications in the haematopoietic stem cell post-transplant period. Most cases are reactivations of latent infections affecting the lung. We present an atypical case of isolated lymph node tuberculosis after an allogeneic haematopoietic stem cell transplantation, which highlights the importance of having a high suspicion index, even in non-endemic countries.