Non-tuberculous mycobacterial infection localized in small intestine developing after allogeneic bone marrow transplantation

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.

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.

Pulmonary Mycobacterium abscessus Infection with Reactive AA Amyloidosis: A Case Report and Brief Review of the Literature

We herein report a case involving a 64-year-old Japanese woman with a pulmonary Mycobacterium abscessus infection complicated by reactive AA amyloidosis, which, to our knowledge, has not been reported to date. The patient underwent gastrointestinal endoscopy for diarrhea during the treatment of pulmonary M. abscessus infection and was diagnosed with AA amyloidosis according to the histopathological findings from the endoscopic specimen. She died four months later. The prognosis of AA amyloidosis associated with pulmonary M. abscessus infection may be very poor, and physicians should pay attention to this rare condition when difficult-to-treat diarrhea occurs in patients with pulmonary M. abscessus infection.

A Case of Rapid Exacerbation of Pulmonary Mycobacterium Avium Complex Infection Mimicking Pulmonary Aspergillosis

We herein report a case of pulmonary Mycobacterium avium complex (MAC) infection with pulmonary multiple nodules and the "halo sign" on chest computed tomography (CT) in which the patient showed rapid exacerbation seven years after undergoing bone marrow transplantation (BMT). A 68-year-old Japanese female visited our hospital due to a productive cough and dyspnea. She had undergone allogeneic BMT for acute myelocytic leukemia and received both prednisolone (2 mg/day) and cyclosporine (30 mg/day). Chest CT demonstrated no abnormal findings on admission; however, multiple pulmonary nodules and the "halo sign" were detected three weeks later. Although a fungal infection was initially suspected, a bronchoscopic examination revealed pulmonary MAC infection. In the present case, pulmonary MAC infection exhibited rapid progression with unique CT findings. Physicians should consider MAC infection in the differential diagnosis in patients who receive BMT and/or immunosuppressive agents, even if the clinical and radiological findings are atypical of the disease.

Gastrointestinal pathology in transplant patients

The assessment of gastrointestinal (GI) specimens from transplant patients is complicated by the wide range of potentially rare pathologies that may be found in this clinical setting. Acute GI graft-versus-host disease (GvHD) is characterized by epithelial cell apoptosis, although there is increasing recognition that acute and/or chronic inflammation may also be present. By contrast, thus far there are no histological features known to be specific to chronic GI GvHD. Mycophenolate mofetil colitis may mimic both GvHD and inflammatory bowel disease, whereas both cytomegalovirus (CMV) and adenovirus infections can cause gland apoptosis. Post-transplant lymphoproliferative disorder should be considered if a Crohn's-like histological picture is seen, and granulomas in biopsies from umbilical cord blood recipients should raise a suspicion of cord colitis syndrome. Finally, the GI tract may be involved directly or indirectly by the disease that originally required haematopoietic stem cell or liver transplantation.

Diseases caused by nontuberculous mycobacteria in Asia

 The isolation rate of nontuberculous mycobacteria (NTM) species and the prevalence of NTM-associated diseases are on the rise in Asian, as well as in Western countries; however, the species distribution of NTM isolates and the types of diseases caused by NTM species vary from region to region. In this review, we present an update on the epidemiology of NTM in Asia. We demonstrate that the distribution of NTM species varies within Asia and differs from that in North America and Europe. In addition, the clinical manifestations of NTM diseases include respiratory tract infections, disseminated infections, skin and soft tissue infections, lymphadenitis, empyema, ocular infections, CNS infections and genitourinary infections. Finally, the rate of adaptive resistance of anti-NTM antimicrobial agents remains high and may be associated with a poor outcome for patients with NTM diseases.

Development and evaluation of multiplex PCR in rapid diagnosis of abdominal tuberculosis

The clinical features of abdominal tuberculosis (TB) are non-specific and establishing a diagnosis remains a challenge. A delay in diagnosis is likely to increase the morbidity in these patients. We developed a multiplex polymerase chain reaction (PCR) using 16SrRNA, IS6110, and devR, and evaluated it in comparison with other conventional tests in clinical suspects of abdominal TB. A total of 183 patients with clinical suspicion of abdominal TB (96 patients with intestinal TB and 87 with peritoneal TB) were enrolled for the study. Endoscopic or intraoperative biopsies were collected from patients suspected of intestinal TB and ascitic fluid was collected from patients with a suspicion of peritoneal TB. Of the intestinal tuberculosis group, there were 40 confirmed cases and 56 controls, while of the peritoneal tuberculosis group there were 37 confirmed cases and 50 controls. Multiplex PCR showed a high sensitivity and specificity in both the intestinal TB and peritoneal TB groups. When combined with histopathology, multiplex PCR could detect 97.5% of all the cases in the intestinal tuberculosis group, while in combination adenosine deaminase levels (ADA) in cases of peritoneal tuberculosis it increased the specificity of diagnosis of peritoneal tuberculosis to 95%. In combination with histopathology in suspected intestinal TB cases, and ADA testing in suspected peritoneal TB cases, it can be used as a highly sensitive, specific, and rapid diagnostic tool with the ability to supplement the limitations of other diagnostic modalities.

Gastrointestinal infections after transplantation

PURPOSE OF REVIEW

Recipients of both solid organ transplant and hematopoietic stem cell transplantation are at increased risk for infectious morbidity and mortality after transplantation due to on-going immunosuppression. Gastrointestinal infections have been increasingly reported in these populations.

RECENT FINDINGS

Increased reports of gastrointestinal infections including bacterial infection with Clostridium difficile, viral infection with norovirus and parasitic pathogens like cryptosporidium are emerging. Risk factors identified have focused on type of transplant, transplant immunosuppression regimens and exposures. Although many events are self-limiting, significant morbidity and rare mortality are reported.

SUMMARY

Improved diagnostic techniques have increased the reporting of several gastrointestinal infections after transplantation, affording improved understanding of the epidemiology of these diseases. Armed with this emerging data, prevention, recognition of infection and treatment strategies can be more thoroughly assessed in these at-risk populations.

Tuberculosis in hematopoietic stem cell transplant recipients

Literature on tuberculosis (TB) occurring in recipients of Hematopoietic Stem Cell Transplant (HSCT) is scanty even in countries where TB is common. Most reports of TB in HSCT patients were from ASIA, in fact the TB incidence ranging from 0.0014 (USA) to 16% (Pakistan). There are few reports of TB diagnosis during the first two weeks after HSCT; most of cases described in the literature occurred after 90 days of HSCT, and the lung was the organ most involved. The mortality ranged from 0 to 50% and is higher in allogeneic HSCT than in autologous. There is no consensus regarding the screening with tuberculin skin test or QuantiFERON-TB gold, primary prophylaxis for latent TB, and whether the epidemiologic query should be emphasized in developing countries with high prevalence of TB.