Tuberculosis and hematopoietic stem cell transplant: Review of a difficult and often underestimated problem

Recipients of solid organ transplants (SOT) and stem cell transplants (SCT) constitute a group of patients at risk for tuberculosis (TB) development. The prevalence of active TB in patients undergoing SOT is higher than in patients undergoing SCT, probably due to the shorter period of immunosuppression in the latter. We reviewed the importance of SCT in individuals with hematological malignancies. Most TB cases occur in transplant patients by reactivation of latent infection after immunosuppression, most often within the first year after transplant, leading to graft loss and in some cases, death. Relevant variables to assess the risk of TB infection in a transplant recipient include the donor’s and recipient’s medical histories, imaging results, microbiology and tuberculin skin test (TST) and interferon-gamma release assays (IGRA). TST is routinely performed in the donor and recipient before transplantation. If TST is > 5 mm in the recipient or > 10 mm in the donor, it is necessary to exclude active TB (pulmonary and renal). Chemoprophylaxis is recommended in TST (+) recipients and in recipients with recent seroconversion, in donors with a history of untreated TB or in contact with an individual with active TB, if radiological images are suspicious and the IGRA is (+). The drug of choice is isoniazid. These topics are herewith reviewed.     

Respiratory Viral Infections in Pediatric Solid Organ and Hematopoietic Stem Cell Transplantation

Respiratory viruses are common in children, including pediatric recipients of both solid organ transplantation and hematopoietic stem cell transplantation. The prevalence and risk factors in each of these groups are reviewed. Furthermore, associated morbidity and mortality in pediatric transplant recipients with respiratory viral infections are addressed. The literature on specific prevention and treatment options for respiratory syncytial virus, adenovirus, influenza, and other respiratory viruses in pediatric solid organ and hematopoietic stem cell transplant recipients is reported.     

Fluoroquinolones for the treatment of latent Mycobacterium tuberculosis infection in liver transplantation

Solid organ transplantation(SOT)is the best treatment option for end-stage organ disease.Newer immunosuppressive agents have reduced the incidence of graft rejection but have increased the risk of infection,particularly due to the reactivation of latent infections due to opportunistic agents such as Mycobacterium tuberculosis.Active tuberculosis(TB)after SOT is a significant cause of morbidity and mortality.Most cases of posttransplant TB are secondary to reactivation of latent tuberculosis infection(LTBI)due to the effects of long-term immunosuppressive therapy.Risk minimization strategies have been developed to diagnose LTBI and initiate treatment prior to transplantation.Isoniazid with vitamin B6 supplementation is the treatment of choice.However,liver transplantation(LT)candidates and recipients have an increased risk of isoniazid-induced liver toxicity,leading to lower treatment completion rates than in other SOT populations.Fluoroquinolones(FQs)exhibit good in vitro antimycobacterial activity and a lower risk of drug-induced liver injury than isoniazid.In the present review,we highlight the disease burden posed by posttransplant TB and summarize the emerging clinical evidence supporting the use of FQs for the treatment of LTBI in LT recipients and candidates.     

Donor‐derived tuberculosis (TB): isoniazid‐resistant TB transmitted from a lung transplant donor with inadequately treated latent infection

Donor‐derived tuberculosis (TB) is an increasingly recognized complication of solid organ transplantation. We report a case of isoniazid‐resistant pulmonary TB in a lung transplant recipient. The patient acquired the infection from the lung donor who was previously empirically treated with isoniazid for latent TB. The case highlights the caveat that, while adequate treatment of latent TB with isoniazid is presumed, meticulous screening of donors is required.     

Pulmonary tuberculosis in allogeneic hematopoietic stem cell transplantation

Pulmonary tuberculosis (TB) is an endemic infectious disease in Taiwan. A retrospective study was conducted to define clinical manifestations and outcomes of patients with pulmonary TB among hematopoietic stem cell transplantation (HSCT) recipients. We identified eight out of 350 HSCT recipients as having pulmonary TB over a 6-year period. The relative risk of having pulmonary TB after HSCT was 13.1-fold higher than in the general population. There was a trend toward increased risk of having pulmonary TB in allogeneic HSCT as compared to autologous HSCT (4.8 +/- 1.8% vs 0, P = 0.067). All the eight patients with pulmonary TB received allogeneic HSCT and most (seven of eight patients) developed the infection during treatment for GVHD. Computed tomography of the chest was normal in one patient, with the rest showing either interstitial (two patients) or alveolar infiltrates (five patients) at the onset of pulmonary TB. The four fatal cases had an obviously shorter duration between HSCT and onset of infection. Our data suggest that pulmonary TB in HSCT recipients is not uncommon in this endemic area. Therefore, an effective strategy of prophylactic treatment for candidates and recipients of allogeneic HSCT, who may have latent pulmonary TB infection, must be developed.     

Pulmonary complications of solid organ and hematopoietic stem cell transplantation

The ability to successfully transplant solid organs and hematopoietic stem cells represents one of the landmark medical achievements of the twentieth century. Solid organ transplantation has emerged as the standard of care for select patients with severe vital organ dysfunction and hematopoietic stem cell transplantation has become an important treatment option for patients with a wide spectrum of nonmalignant and malignant hematologic disorders, genetic disorders, and solid tumors. Although advances in surgical techniques, immunosuppressive management, and prophylaxis and treatment of infectious diseases have made long-term survival an achievable goal, transplant recipients remain at high risk for developing a myriad of serious and often life-threatening complications. Paramount among these are pulmonary complications, which arise as a consequence of the immunosuppressed status of the recipient as well as from such factors as the initial surgical insult of organ transplantation, the chemotherapy and radiation conditioning regimens that precede hematopoietic stem cell transplantation, and alloimmune mechanisms mediating host-versus-graft and graft-versus-host responses. As the population of transplant recipients continues to grow and as their care progressively shifts from the university hospital to the community setting, knowledge of the pulmonary complications of transplantation is increasingly germane to the contemporary practice of pulmonary medicine.     

Hepatitis E infection in HIV‐infected liver and kidney transplant candidates

Hepatitis E virus (HEV) has been reported to cause acute and chronic hepatitis in those with HIV infection and among solid organ transplant recipients in Europe. Limited data indicate that HEV is endemic in the United States, but the prevalence and significance of HEV infection among those with HIV and awaiting solid organ transplantation is unknown. We evaluated anti‐HEV IgM and IgG antibodies and HEV RNA in 166 HIV‐infected solid organ transplant candidates enrolled in the NIH HIV‐Transplant Cohort. Overall prevalence of anti‐HEV IgG approached 20% in both liver and renal transplant candidates. Evidence of recent infection was present in approximately 2% of liver transplant candidates and none of the kidney transplant candidates. HEV RNA was not detected in any patient. We conclude that markers of HEV infection are frequent among candidates for transplantation, but active, ongoing viremia is not seen. Evidence of recent infection (acute on chronic) liver disease was present in liver but not kidney recipients.     

Tuberculous hepatitis in renal transplant recipients following alemtuzumab induction therapy

Mycobacterium tuberculosis infection is one of many opportunistic infections in renal transplant recipients, arising either from reactivation of latent infection or de novo infection, occasionally donor derived. M. tuberculosis hepatitis has never been reported in patients who have received alemtuzumab as part of their renal transplant management. We describe 2 patients who underwent deceased‐donor renal transplantation following alemtuzumab induction therapy and presented with a febrile syndrome, subsequently diagnosed as tuberculous hepatitis, one with disseminated disease. Both responded well to treatment without significant side effects, resulting in excellent graft function. The importance of chemoprophylaxis should be emphasized to minimize the risk of developing active tuberculosis in patients with latent tuberculosis infection undergoing solid organ transplantation.     

Paradoxical immune reconstitution inflammatory syndrome associated with disseminated tuberculosis infection in an unrelated donor cord blood transplant recipient

Tuberculosis (TB) is an infrequent infection after hematopoietic cell transplant (HCT), with associated mortality up to 30%. The utility of universal screening for latent TB in HCT candidates is controversial due to the lack of sensitive screening tests. We describe a case of disseminated TB infection complicated by immune reconstitution inflammatory syndrome in an adult double unit umbilical cord blood transplant recipient who originated from the United Arab Emirates.     

Vaccines for transplant recipients

Immune dysregulation and immunosuppression regimens impact on the ability of transplant recipients to respond to immunizations. The distinct challenges of immunizations to benefit stem cell transplant recipients and solid organ transplant recipients are discussed separately. Recommended vaccines for stem cell transplant recipients and solid organ transplant candidates are suggested. New approaches to consider to enhance immune responses of transplant recipients are discussed.     

Paradoxical worsening of tuberculosis in a heart–lung transplant recipient

We report on a heart-lung transplant recipient who presented with pulmonary tuberculosis (TB) 2.5 months after transplantation and then developed a paradoxical reaction after 4 months of adequate anti-TB treatment. She eventually recovered with anti-TB and high-dose steroid treatments. METHODS: Using sequential bronchoalveolar lavages, we assessed the inflammatory response in the lung and investigated the alveolar immune response against a Mycobacterium tuberculosis antigen. RESULTS: The paradoxical reaction was characterized by a massive infiltration of the alveolar space by M. tuberculosis antigen-specific CD4(+) T cells and by the presence of a CD4(-)CD8(-) T lymphocyte subpopulation bearing phenotypic markers (CD16(+)/56(+)) classically associated with NK cells. CONCLUSION: This case report illustrates that even solid organ transplant recipients receiving intense triple-drug immune suppression may be able to develop a paradoxical reaction during TB treatment. Transplant physicians should be aware of this phenomenon in order to differentiate it from treatment failure.     

Viral infections in immunocompromised patients: what's new with respiratory viruses?

PURPOSE OF REVIEW: The leading cause of death in solid organ and hematopoietic stem cell transplant recipients is infection. The respiratory viruses, particularly respiratory syncytial virus, influenza, parainfluenza, adenovirus, and picornaviruses, are increasingly recognized as significant pathogens in these populations. RECENT FINDINGS: Respiratory syncytial virus has again been found to be the most common of the respiratory viruses causing severe infections in transplant recipients. Advances in prevention, particularly with regard to infection control practices, and to lesser extent treatment have had a substantial impact on the frequency and outcomes of this infection. New studies have clarified the impact of influenza in the hematopoietic stem cell transplant recipients and have provided evidence to support the use of M2 and neuraminidase inhibitors for early treatment. The epidemiology of parainfluenza and adenovirus in transplant recipients has been clarified, although therapeutic modalities are still limited and understudied. New antiviral medications may bring improved outcomes of picornavirus infections in this population. Finally, a new virus, the human metapneumovirus, has recently been described and may be a significant respiratory pathogen in immunocompromised transplant recipients. SUMMARY: Studies published over the past year have documented a new respiratory pathogen. They have also resulted in improved understanding of the epidemiology of all of the respiratory virus pathogens, and have contributed to improve management of respiratory syncytial virus and influenza infection in hematopoietic stem cell transplant and solid organ transplant recipients.     

Primary cutaneous mucormycosis in a lung transplant recipient: case report and concise review of the literature

Abstract: Mucormycosis (zygomycosis) is an invasive, opportunistic fungal infection caused by organisms of the class Zygomycetes. Immunocompromised individuals, including both solid organ and hematopoietic stem cell transplant recipients, are preferentially affected. Among solid organ transplant (SOT) recipients, the sinuses, with or without involvement of the orbits and cerebrum, are the most common sites of disease, although the pulmonary allograft appears to be targeted following lung transplantation. Here, we describe the unique case of a lung transplant recipient who developed multifocal cutaneous mucormycosis without involvement of the pulmonary allograft, and review the published literature regarding incidence, treatment, and prognosis of primary cutaneous mucormycosis following SOT.     

Latent tuberculosis infection: recommendations for preventive therapy in adults in Germany

The immunologic mechanisms of latent tuberculosis (TB) infection are complex and hitherto not completely understood. The lifelong risk of an immunocompetent individual of developing active TB after infection with M. tuberculosis is 5-10 % and highest during the first two years after infection. Various factors may considerably increase the risk of developing active TB, e. g., immunosuppressive disease or immunosuppressive medication. However, the development of active TB may be avoided by preventive chemotherapy, the therapy of choice being isoniazid over a 9-month period. Alternative treatment regimens may be indicated in special cases, but it must be borne in mind that the efficacy of these regimens has not been studied sufficiently while they seem to be less well tolerated than isoniazid monotherapy. The tuberculin skin test is still the only sufficiently documented method to detect latent infection with M. tuberculosis which is also suitable for routine application. This test today should be performed exclusively as described by Mendel and Mantoux. Its sensitivity and specificity depend on the prevalence of tuberculosis infection. It should therefore be restricted to individuals at increased risk of latent TB infection. When interpreting the tuberculin skin test, it is necessary to know whether an individual belongs to one of the defined risk groups or has an elevated risk of developing active TB. Among the risk groups are individuals who may have been infected recently with M. tuberculosis (contacts of contagious TB patients) or in whom other factors increase their risk of developing active TB. The indication for chemotherapy for latent TB infection must be based on a careful individual risk-benefit analysis and, besides patient compliance, requires full information of the patient and careful monitoring during therapy. Before initiating treatment, active TB must always be excluded by the proven methods.     

Treatment issues surrounding hepatitis C in renal transplantation: a review

Hepatitis C infection is prevalent in candidates for and recipients of solid organ transplants. In the renal transplant population, HCV infection has been shown to decrease long-term patient and graft survival. The outcomes of HCV in recipients of other solid organ transplants are yet to be established and prospective studies will be needed in the future. In the absence of effective and safe antiviral treatment for HCV infection in renal, heart, and lung transplant recipients, the management of these patients remains a challenge and has led to an increased focus on identifying and treating hepatitis C in patients prior to transplantation. Interferon-based therapy for HCV prior transplantation appears to improve outcomes after transplantation. On the other hand, post-transplant interferon therapy is associated with an increased risk of graft rejection. Given the paucity of information on HCV treatment in solid organ transplant recipients, there is a great need for large-scale, multi-centre randomized controlled trials to determine the optimal approach to HCV infection in this population. This article will summarize the current peer-reviewed literature focusing on the efficacy of amantadine, ribavirin and both standard and pegylated interferon in the treatment of chronic hepatitis C in renal, transplant recipients.     

Liver transplantation: an unheralded probable risk for tuberculosis.

We present a patient who underwent orthotopic liver transplantation and died of previously undiagnosed pulmonary tuberculosis (TB). TB is known to complicate liver transplantation in rare circumstances. Liver transplantation is an unheralded risk factor for development of TB because of possible activation of latent infection or primary TB in immunosuppressed hosts. A tuberculin skin test should always be performed preoperatively. Preventive treatment with isoniazid is indicated when immunosuppressive therapy is started in patients with high TB risk. Radiographic signs of previous granulomatous disease may be important when tuberculin skin test is negative, unknown or anergy is present. TB is preventable--with a high degree of suspicion where TB is endemic and proactive programs, most TB cases in transplant recipients can be avoided.     

Multidrug‐resistant tuberculosis in transplant recipients: Case report and review of the literature

Transplant recipients are at increased risk of tuberculosis (TB). We describe a case of pulmonary and vertebral multidrug‐resistant TB (MDR‐TB) in a kidney transplant patient who required neurosurgical intervention and unfortunately developed fatal nosocomial complications. Thirteen transplant recipients with MDR‐TB were previously reported in the literature (one hematopoietic cell transplant, one heart transplant, one lung transplant, one heart‐lung transplant, and nine kidney transplant recipients). Extrapulmonary disease, severe treatment complications, and deaths were observed in patients who developed MDR‐TB after transplantation.     

Disseminated tuberculosis following reduced-intensity cord blood transplantation for adult patients with hematological diseases

Allogeneic hematopoietic stem cell transplantation (allo-SCT) recipients are prone to infections. The incidences of mycobacterial infections after allo-SCT in several case series vary from less than 0.1-5.5%. However, no study has been published on tuberculosis following unrelated cord blood transplantation (UCBT). We retrospectively reviewed medical records of 113 adult patients with a median age of 54 years who underwent reduced-intensity UCBT (RI-UCBT) at Toranomon Hospital from March 2002 to May 2004. Mycobacterium tuberculosis infections were diagnosed in three patients (2.7%), of these two patients developed primary infection and one patient developed reactivation of latent tuberculosis. The interval between RI-UCBT and the diagnosis of tuberculosis was 34, 41 and 61 days. All the patients had disseminated disease at diagnosis. Histological examination showed the lack of granuloma in caseous necrosis. Combination antituberculous treatments showed limited efficacy, and two patients died immediately after diagnosis. M. tuberculosis caused life-threatening illness, rapidly progressing in RI-UCBT recipients. The lack of granuloma in caseous necrosis suggests the impaired T-cell function in early post transplant phase of RI-UCBT. We should consider M. tuberculosis in the differential diagnoses of fever of unknown source after RI-UCBT.     

Clinical features and outcome of tuberculosis in solid organ transplant recipients

BACKGROUND:: Taiwan is an area with moderate to high incidence of Mycobacterium tuberculosis infection. The risk of M tuberculosis infection in transplantation recipients is considered to be significant. Our aim in this study was to investigate the clinical spectrums of M tuberculosis-infected transplantation recipients in a southeast Asian country, Taiwan. METHODS:: We retrospectively analyzed the demographic data, clinical features, treatment, and outcome of M tuberculosis infection in kidney, heart, and liver transplant recipients from May 1996 to April 2005 at the National Taiwan University Hospital. RESULTS:: Fifteen patients who had received solid organ transplantation developed tuberculosis (kidney = 6, heart = 7, liver = 2). The median duration from transplantation to diagnosis of tuberculosis was 31 months. The cumulative incidence of post-transplantation tuberculosis was 2.0% (15/760), ie, approximately 3 times that of the general population. Ten patients (66.7%) had pulmonary tuberculosis, 1 (6.7%) had extrapulmonary tuberculosis, and 4 (26.7%) had disseminated tuberculosis. Nine patients completed the anti-tuberculosis treatment; the median treatment duration was 12 months (pulmonary: 9 months; extrapulmonary: 13.5 months). No treatment failure was noted in patients receiving the complete treatment course. The graft failure and mortality rates of post-transplantation tuberculosis were 13.3% each (2/15). The tuberculosis-associated mortality rate was 6.7% (1/15). CONCLUSIONS:: Cumulative incidence of tuberculosis was slightly higher in transplant recipients than in the general population in Taiwan. Conventional 4-combined anti-tuberculosis regimen for 12 months can treat the potentially fatal infection successfully in post-transplantation tuberculosis patients without recurrence.     

Persistent parvovirus B19 infection resulting in red cell aplasia after allogeneic hematopoietic stem cell transplantation

Persistent parvovirus B19 (PVB) infection has been reported sporadically in immunocompromised patients including hematopoietic stem cell and solid organ transplant recipients. However, the pathogenesis of persistent infection has yet to be fully elucidated. We report here a patient with multiple myeloma developing red cell aplasia during the hematopoietic recovery after allogeneic hematopoietic stem cell transplantation (HSCT) caused by PVB. The patient had already had PVB viremia before transplantation and remained asymptomatic. The route of PVB transmission was considered to be direct contact with the patient's family member with primary PVB infection 1 month before transplantation. Treatment with intravenous immunoglobulin resulted in prompt resolution of anemia. These findings suggest that monitoring of PVB DNA is recommended for patients undergoing HSCT and having contact with individuals with documented PVB infection, even if they are asymptomatic.