Mycobacterial infections in renal allograft recipients

TB in paediatric kidney transplant recipients - A single-centre experience

BACKGROUND

TB remains a major challenge in transplantation, particularly in endemic countries. This study aimed to describe the incidence, clinical presentation and outcomes of TB in paediatric kidney transplant recipients and to assess the impact of INH prophylaxis.

METHODS

Single-centre retrospective descriptive analysis of children who received kidney transplants from 1995 to 2019 was carried out. The cohort was stratified according to receipt of INH prophylaxis which began in 2005.

RESULTS

A total of 212 children received a kidney transplant during the study period. Median age at transplantation was 11.2 years (IQR: 2.2-17.9), and 56% were males. TB was diagnosed in 20 (9%) children, with almost two-thirds (n = 12) occurring within the first year. Most infections were pulmonary. The main presenting symptoms included fever (n = 13/20), weight loss (n = 12/20) and cough (n = 10/20). TST was positive in four of 20 children. Coinfection with EBV, CMV or Staph was found in five children. Due to drug interactions, an up to threefold increase in calcineurin inhibitor dose was required to maintain therapeutic blood levels. INH prophylaxis was protective against development of TB (p = .04). Gender, age and type of allograft were not significant risk factors. Graft and patient survival was 100% upon completion of TB treatment.

CONCLUSION

Kidney transplant recipients in endemic countries have a high risk of developing TB. Diagnosis remains a challenge. Frequent and meticulous monitoring of immunosuppression drug levels during treatment of TB is required to avoid loss of patient or graft. INH prophylaxis protects against development of TB in this population.

Tuberculosis prevention in patients undergoing kidney transplantation: A nurse-led program for screening and treatment

BACKGROUND

Systematic screening for, and treatment of, latent tuberculosis (TB) infection is recommended prior to kidney transplant. However, little is known about patient compliance with, or the safety profile of, preventive therapies used in clinical practice.

METHODS

This was a retrospective observational study of patients who were eligible for kidney transplant and were evaluated for TB infection between January 2013 and June 2019 at the TB clinic of a tertiary care teaching hospital. All patient data were registered prospectively as part of our nurse-led program before kidney transplant. We assessed completion rates, tolerance with therapy, development of TB, and associated workload.

RESULTS

In total, 1568 patients were referred to our TB clinic for evaluation. Preventive therapy was given to 385 patients and completed by 340 (88.3%). Of these, 89 (23.1%) experienced some intolerance, with 27 requiring full discontinuation. After a median follow-up of 45 months (1426 patient-years), 206 (53.5%) of the treated patients received a kidney transplant; only one patient, who failed to complete treatment, developed post-transplant TB (7.01 cases per 10 000 patient-years; 95% confidence interval, 0.35-34.59). Extra nurse or medical visits were required by 268 (69.6%) patients.

CONCLUSION

Despite the complexity and workload generated by patients with ESRD awaiting kidney transplant, preventive therapy for TB is effective in most cases. Our experience provides important evidence on the feasibility of preventive therapy for TB before kidney transplant when delivered as part of a comprehensive nurse-led program.

Prevention and treatment of tuberculosis in solid organ transplant recipients

Introduction: Tuberculosis (TB) in solid organ transplant (SOT) recipients is associated with significant morbidity and mortality. Its management in transplant recipients is difficult and highly complex, given the underlying immunosuppression and the risks of drug-drug interactions imposed by immunosuppressive drugs that are needed to maintain the transplant allograft.Areas covered: We provide a brief review of TB in SOT and discuss the clinical indications, mechanisms of action and drug resistance, drug-drug interactions, and adverse effects of anti-TB drugs. We provide a summary of recent clinical trials, which serve as the foundation for current recommendations. We further include relevant updates on new agents being evaluated for clinical use in TB management.Expert commentary: TB causes significant morbidity in SOT recipients. The drugs used in the treatment for latent TB and active disease in SOT are similar to the regimens used in the general population. However, TB disease in transplant recipients is more difficult to manage because of the potential for hepatotoxicity and the complex drug-drug interactions with immunosuppressive drugs. We believe that alternative regimens suited for the vulnerable transplant population, and more therapeutic drug options are needed given the adverse toxicities associated with currently approved anti-TB drugs.

Treatment of latent TB Infection and the risk of tuberculosis after solid organ transplantation: Comprehensive review

BACKGROUND

Mycobacterium tuberculosis disease may occur after treatment of latent TB infection (LTBI). Prompted by a case of reactivation TB disease in a solid organ transplant (SOT) recipient who received LTBI treatment, we reviewed the literature to examine outcomes, adverse effects, resistance, and treatment choices of tuberculosis after LTBI therapy.

METHODS

MEDLINE and Web of Science from inception to 5/2019 were reviewed using key words "latent tuberculosis infection" and "SOT" or "transplantation." The search yielded nine cases, 41 cohort studies and six randomized controlled trials (RCT).

RESULTS

Cohort and RCT demonstrated significant reduction in TB disease among transplanted patients who received LTBI therapy; only 56/2651 (2.1%) SOT patients developed TB after LTBI therapy. Adverse drug reactions occurred in 149/1148 (12.9%) and 73/641 (11.4%) of cohort and RCT patients, respectively. Among liver recipients, 56/266 (21%) developed side effects, of which half (29/56, 51.8%) was INH-related. There was no reported INH resistance.

CONCLUSIONS

Latent TB infection treatment is efficacious in SOT recipients at risk of TB disease. However, tuberculosis may still occur despite LTBI treatment. Hepatotoxicity associated with LTBI therapy is infrequent, although more commonly observed among liver recipients.

Incidence, Outcomes, and Long-term Immune Response to Tuberculosis in Organ Transplant Recipients

BACKGROUND

Tuberculosis (TB) is a significant opportunistic infection in solid organ transplant recipients (SOTR). There are limited data on TB incidence in transplantation from low prevalence countries as well as on long-term TB-specific immune responses.

METHODS

We performed a single-center retrospective review of SOTR diagnosed with active TB between 2000 and 2015 and further contacted the available patients for a study of long-term T-cell responses using an interferon-gamma (IFN-γ) release assay and a flow cytometry-based assay.

RESULTS

We identified 31 SOTR with active TB for an incidence of 62 cases/100 000 patient-years. Nineteen (61.3%) of 31 patients were diagnosed within the first year after transplant. Nineteen (61.3%) were born in countries with high TB prevalence and disseminated disease occurred in 22.6%. No patient had been screened for latent TB infection pretransplant. The majority of patients received isoniazid and a rifamycin as part of multidrug regimen. In addition, 13 (44.8%) of 29 patients received quinolones. One-year mortality in this population was 19.4%. Eight patients were available for long-term immune responses. Of these, all had detectable IFN-γ response by IFN-γ release assay testing and 7 of 8 had detectable TB-specific T cells, primarily central and effector T-cell responses in the CD4 compartment and terminally differentiated T cells in the CD8 compartment.

CONCLUSIONS

TB has high incidence in SOTR even in low-prevalence regions but especially targets patients who originated from TB-endemic countries. Long-term TB-specific T-cell responses were found in the majority of patients.

Management of Mycobacterium Other than Tuberculosis in Solid Organ Transplantation

Mycobacteria other than tuberculosis are important pathogens to consider in solid organ transplant recipients. Delay in recognition and treatment may incur significant morbidity and mortality. Management of mycobacteria other than tuberculosis requires a knowledge of treatment specific for each species and drug-drug interactions between antimicrobial and immunosuppressive drugs. Therapy in solid organ transplant can be prolonged and may require a reduction in immunosuppression to improve outcomes.

Non-tuberculous mycobacterial infections in solid organ transplant recipients: An update

Non-tuberculous mycobacteria are ubiquitous environmental organisms that are now increasingly recognized as important causes of clinical disease in solid organ transplant recipients. Risk factors of non-tuberculous mycobacteria infection are severe immunologic defects and structural abnormalities. Lung transplant recipients are at higher risk for non-tuberculous mycobacterial disease compared to recipients of other solid organs. The clinical presentation could be skin and soft tissue infection, osteoarticular disease, pleuropulmonary infection, bloodstream (including catheter-associated) infection, lymphadenitis, and disseminated or multi-organ disease. Management of non-tuberculous mycobacteria infection is complex due to the prolonged treatment course with multi-drug regimens that are anticipated to interact with immunosuppressive medications. This review article provides an update on infections due to non-tuberculous mycobacteria after solid organ transplantation, and discusses the epidemiology, risk factors, clinical presentation, and management.

Mycobacterium kansasii pericarditis in a kidney transplant recipient: a case report and comprehensive review of the literature

Mycobacterium kansasii is the second most common non-tuberculous mycobacteria in kidney transplant recipients (KTRs) and has been reported to cause disseminated infection in KTRs. We report the first case to our knowledge of M. kansasii pericarditis after kidney transplantation in a 54-year-old man. The patient was admitted with a 2-month history of intermittent fever and myalgia, treated with oral prednisolone and mycophenolate mofetil prior to admission. Chest computed tomography showed enlarged mediastinal lymph node and small amount of pericardial effusion. Mediastinoscopic biopsy of mediastinal lymph node revealed reactive hyperplasia, without evidence of granuloma, but acid-fast bacilli stain of pericardial fluid reported positive finding and pericardial fluid culture identified M. kansasii. The patient has been treated successfully with rifabutin-based combination therapy. All available cases of M. kansasii infection in kidney transplant patients and M. kansasii pericarditis in human immunodeficiency virus-infected patients are comprehensively reviewed.

Tuberculosis in renal transplant recipients: the evidence for prophylaxis

BACKGROUND

Tuberculosis (TB) remains a leading cause of death in endemic countries and is 20 to 70 times more common in renal transplant recipients, where it contributes to both increased morbidity and mortality. This review will focus on the epidemiology of TB in renal transplant recipients and critically appraise the published literature on isoniazid prophylaxis in renal transplantation.

METHODS

A literature search for randomized and nonrandomized studies investigating the use of isoniazid prophylaxis in renal transplant recipients was conducted using Ovid MEDLINE, the Cochrane Library, the Transplant Library, and EMBASE. Relative risks (RRs) with 95% confidence intervals (CIs) are reported. Meta-analysis of the randomized controlled trials (RCTs) was performed with a fixed-effects model.

RESULTS

Eleven relevant studies were identified; six nonrandomized and five RCTs. The nonrandomized studies indicate a reduced risk of TB with isoniazid prophylaxis. The RCTs demonstrated conflicting results, with two studies finding a reduction in TB with prophylaxis and two studies finding no difference. Meta-analysis of the 709 patients from the four RCTs demonstrated a reduced risk of TB with isoniazid prophylaxis (RR, 0.31; 95% CI, 0.19-0.51). No significant difference was found in the incidence of hepatitis (RR, 1.22; 95% CI, 0.91-1.65).

CONCLUSION

Both randomized and nonrandomized studies support the value of isoniazid as TB prophylaxis in renal transplant recipients at risk of active infection. Clinicians should consider prophylaxis in renal transplant recipients in endemic areas or in recipients in nonendemic countries who are at risk. However, the evidence for the benefit of isoniazid prophylaxis in renal transplantation is not robust and there is still a need for a large multicenter trial of isoniazid prophylaxis in kidney transplantation in an endemic area.

Mycobacterium tuberculosis in a renal transplant transmitted from the donor

BACKGROUND

Disease caused by Mycobacterium tuberculosis (MTB) is a well-recognised complication of renal transplantation worldwide due to immunosuppression. It is more common in developing countries. Infection isolated to a renal allograft is rare and infection transmitted by the allograft is also very rare.

AIM

To describe the first reported case of MTB in a renal transplant transmitted from the donor in Ireland and review the literature.

RESULTS

A 53-year-old male 29 months after allogenic renal transplant for adult polycystic kidney disease with no other risk factors for MTB presented with deteriorating renal function. Pathological examination of a renal biopsy specimen showed caseating granulomata. MTB was confirmed by culture of early morning urine.

CONCLUSIONS

MTB isolated to a renal transplant is rare in the developed world. Such an infection should always be considered as our donor pool becomes increasingly more travelled particularly to endemic areas. The new interferon gamma release assays (IGRA) may be a viable alternative screening method to the tuberculin skin test (TST).

Prospective randomized control trial of isoniazid chemoprophylaxis during renal replacement therapy

BACKGROUND

Infectious diseases remain among the major morbid events in patients with end-stage renal disease (ESRD) on renal replacement therapy (RRT). In developing countries, tuberculosis (TB) has been found to occur more frequently in these patients than in the general population. Efficacy of isoniazid (INH) chemoprophylaxis has been seen in other situations, such as human immunodeficiency virus infection. However, studies on INH prophylaxis in ESRD patients on RRT are limited.

METHODS

In this prospective randomized controlled trial, from April 2000 to June 2001, a total of 109 ESRD patients registered for renal transplant and accepted for maintenance hemodialysis in our hospital were included and followed up until June 2004 to assess the role of INH prophylaxis in preventing development of TB. At the time of acceptance for hemodialysis, 54 patients were assigned to receive daily INH for 1 year and 55 patients were assigned to the control group. Primary outcome was development of TB. Secondary outcome was INH hepatotoxicity. To evaluate the effect of INH prophylaxis on the development of TB, a Kaplan-Meier survival estimate was used to plot TB-free survival curve and log-rank test was used for comparison.

RESULTS

Overall, TB was diagnosed in 27 patients during RRT, with an incidence of 24.8%. TB developed in 9 (16.7%) patients in the INH group and in 18 (32.7%) patients in the control group. There was a significantly lower incidence of TB in the INH group as compared with the control group. The risk ratio of INH vs. control group for development of TB was 0.40 (95% confidence index [CI], 0.17-0.92; P=0.032). In the INH group 27 (50%) patients and in the control group 17 (30.9%) patients developed some hepatic dysfunction. However, significant hepatitis that required discontinuation of INH developed in only 9 (16.7%) patients in the INH group. Furthermore, significant hepatitis also developed in 6 (10.9%) patients in the control group. The majority of patients with significant hepatitis in both groups (INH as well as control) were subsequently found to be positive for hepatitis B and/or hepatitis C viral infection. Mild hepatitis (which did not require discontinuation of INH) was seen in 18 (33.3%) patients in the INH group and 11 (20%) patients in the control group. Viral hepatitis infection was not found in any of the milder cases of hepatitis in either group.

CONCLUSION

This study shows significant efficacy of INH chemoprophylaxis during RRT in preventing development of TB, when the INH was started during dialysis itself. INH chemoprophylaxis was safe and well tolerated in the majority of patients. However, mild hepatic dysfunction was common, both in the treatment as well as in the control group. As the incidence of viral hepatitis overall was high in our patients on RRT, it is difficult to identify INH-induced hepatitis in this clinical setting.

Cellulitis as a manifestation of miliary tuberculosis in a renal transplant recipient

Cutaneous involvement is an unusual presentation of tuberculosis (TB) and is rarely reported in renal transplant recipients. We describe a 37-year-old renal transplant recipient with disseminated Mycobacterium tuberculosis infection that presented as cellulitis. The organism was isolated from tissue and blood cultures. The patient was treated with quadruple anti-TB therapy for 12 months. Anti-TB therapy led to a complete resolution of TB lesions. We also provide a review of the literature on cutaneous TB in renal transplant recipients. Skin TB in renal transplant recipients usually occurs with nontuberculous mycobacteria. The spectrum of the skin lesions can be quite different and can mimic bacterial infections. Mycobacteriosis should always be included in the differential diagnosis of a skin lesion in renal transplant recipients.

Mycobacterium tuberculosis infection incidence in hospitalized renal transplant patients in the United States, 1998-2000

The incidence, risk factors, and prognosis for Mycobacterium tuberculosis (MTB) infection have not been reported in a national population of renal transplant recipients. We performed a retrospective cohort study of 15,870 Medicare patients who received renal transplants from January 1, 1998 to July 31, 2000. Cox regression analysis derived adjusted hazard ratios (AHR) for factors associated with a diagnosis of MTB infection (by Medicare Institutional Claims) and the association of MTB infection with survival. There were 66 renal transplant recipients diagnosed with tuberculosis infection after transplant (2.5 cases per 1000 person years at risk, with some falling off of cases over time). The most common diagnosis was pulmonary TB (41 cases). In Cox regression analysis, only systemic lupus erythematosus (SLE) was independently associated with TB. Mortality after TB was diagnosed was 23% at 1 year, which was significantly higher than in renal transplant recipients without TB (AHR, 4.13, 95% CI, 2.21, 7.71, p < 0.001). Although uncommon, MTB infection is associated with a substantially increased risk of mortality after renal transplantation. High-risk groups, particularly those with SLE prior to transplant, might benefit from intensified screening.

Nontuberculous mycobacterial infection in hematopoietic stem cell and solid organ transplant recipients

Nontuberculous mycobacteria (NTM) are ubiquitous environmental organisms. In immunocompetent hosts, they are a rare cause of disease. In immunocompromised hosts, disease due to NTM is well documented. Reports of NTM disease have increased in hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients. This increase may reflect increased numbers of transplants, intensification of immune suppressive regimens, prolonged survival of transplant recipients, and/or improved diagnostic techniques. The difficulty of diagnosis and the impact associated with infections due to NTM in HSCT and SOT recipients necessitates that, to ensure prompt diagnosis and early initiation of therapy, a high level of suspicion for NTM disease be maintained. The most common manifestations of NTM infection in SOT recipients include cutaneous and pleuropulmonary disease, and, in HSCT recipients, catheter-related infection. Skin and pulmonary lesions should be biopsied for histologic examination, special staining, and microbiologic cultures, including cultures for bacteria, Nocardia species, fungi, and mycobacteria. Mycobacterial infections associated with catheters may be documented by tunnel or blood (isolator) cultures. Susceptibility testing of mycobacterial isolates is an essential component of optimal care. The frequent isolation of NTM other than Mycobacterium avium complex (MAC) from transplant recipients limits the extrapolation of therapeutic data from human immunodeficiency virus-infected individuals to the population of transplant recipients. Issues involved in the management of NTM disease in transplant recipients are characterized by a case of disseminated infection due to Mycobacterium avium complex in a lung transplant recipient, with a review of the relevant literature.

Prospective randomised trial of isoniazid prophylaxis in renal transplant recipient

Renal transplantation (RT) recipients are at a high risk of developing tuberculosis (TB) following transplantation. Effectiveness of isoniazid (INH) in preventing TB is well documented in immunocompetent as well as immunocompromised persons. There is paucity of data on role of INH prophylaxis in RT recipients. Thus, a prospective randomised trial of INH in RT recipients was carried out to determine the efficacy of daily INH monotherapy in the prevention of TB in these patients. Patients of end stage renal disease (ESRD) taken for RT formed the subjects of study. Patients with active TB and active hepatitis at the time of RT were excluded from the study. Patients were randomised to receive INH 300 mg with pyridoxine 20 mg daily from the day of RT. The duration of the treatment was planned for 1 year or till the development of TB, which ever was earlier. Between October 1998 and September 2000, 114 RT were done at our hospital. Of these, 24 (21%) patients had active TB at the time of RT and thus were excluded. Patients included were randomised with 1:2 ratio of treatment and control group. Of the 90 patients thus enrolled, 30 were randomised in treatment group and 60 in control group. Of the included patients five patients had very early graft loss (three in treatment and two in control group) within days and thus excluded from the analysis. Three of the 27 (11.1%) patients in treatment group and 15 (25.8%) in control group developed TB (P = 0.10). The risk ratio of (RR) of INH versus control group of TB was 0.36 (95% CI, 0.10-1.32) but the difference was not statistically significant (P = 0.12). Only one patient developed INH induced hepatitis. In conclusion, with INH prophylaxis, there was a trend towards protection from TB, though it was not statistically significant. Further, all patients tolerated INH and hepatotoxicity was not a major problem in this group of patients.

Tuberculosis in renal transplant recipients: rifampicin sparing treatment protocol

The reactivation of mycobacterium infection in renal transplant recipients in developing countries is a common therapeutic dilemma, especially in those patients receiving cyclosporin immunosuppression. The inclusion of rifampicin in the antituberculosis protocol increases the risk of precipitating acute allograft rejection due to its interaction with cyclosporin and also increases the financial burden. We successfully treated 16 patients who developed mycobacterial infection post renal transplant with a rifampicin sparing antituberculosis drug regimen. Pyrexia of unknown origin was the most common manifestation observed and a therapeutic trial with antituberculosis drugs is justified. De novo diabetes mellitus appears to be an added risk factor and increases the susceptibility to mycobacterial infection.

Mycobacterial infections in patients with chronic renal disease

In this article, the authors have provided a comprehensive review of TB and MOTT infections in patients on renal dialysis and receiving kidney transplants. Because most published series are small retrospective studies or case reports, there are several uncertainties still involved in the diagnosis and treatment of such patients. Unanswered questions include selection of optimal dosage and duration of therapeutic agents; the best tests for screening and diagnosis, especially in high prevalence areas; and the best management of MOTT infections because of unavailability of highly effective therapy.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.

The use of cyclosporine modifies the clinical and histopathological presentation of tuberculosis after renal transplantation

Tuberculosis is one of the most frequent opportunistic infections after renal transplantation and occurred in 30 of 1264 patients transplanted between 1976 and 1996 at Hospital São Paulo - UNIFESP and Hospital Dom Silvério, Brazil. The incidence of 2.4% is five times higher than the Brazilian general population. The disease occurred between 50 days to 18 years after the transplant, and had an earlier and worse development in patients receiving azathioprine, prednisone and cyclosporine, with 35% presenting as a disseminated disease, while all patients receiving azathioprine and prednisone had exclusively pulmonary disease. Ninety percent of those patients had fever as the major initial clinical manifestation. Diagnosis was made by biopsy of the lesion (50%), positivity to M. tuberculosis in the sputum (30%) and spinal cerebral fluid analysis (7%). Duration of treatment ranged from 6 to 13 months and hepatotoxicity occurred in 3 patients. The patients who died had a significant greater number of rejection episodes and received higher doses of corticosteroid. In conclusion, the administration of cyclosporine changed the clinical and histopathological pattern of tuberculosis occurring after renal transplantation.

Infection in the bone marrow transplant recipient and role of the microbiology laboratory in clinical transplantation

Over the past quarter century, tremendous technological advances have been made in bone marrow and solid organ transplantation. Despite these advances, an enduring problem for the transplant recipient is infection. As immunosuppressive regimens have become more systematic, it is apparent that different pathogens affect the transplant recipient at different time points in the posttransplantation course, since they are influenced by multiple intrinsic and extrinsic factors. An understanding of this evolving risk for infection is essential to the management of the patient following transplantation and is a key to the early diagnosis and treatment of infection. Likewise, diagnosis of infection is dependent upon the quality of laboratory support, and services provided by the clinical microbiology laboratory play an important role in all phases of clinical transplantation. These include the prescreening of donors and recipients for evidence of active or latent infection, the timely and accurate microbiologic evaluation of the transplant patient with suspected infection, and the surveillance of asymptomatic allograft recipients for infection. Expert services in bacteriology, mycology, parasitology, virology, and serology are needed and communication between the laboratory and the transplantation team is paramount for providing clinically relevant, cost-effective diagnostic testing.

Infections in solid-organ transplant recipients

Solid-organ transplantation is a therapeutic option for many human diseases. Infections are a major complication of solid-organ transplantation. All candidates should undergo a thorough infectious-disease screening prior to transplantation. There are three time frames, influenced by surgical factors, the level of immunosuppression, and environmental exposures, during which infections of specific types most frequently occur posttransplantation. Most infections during the first month are related to surgical complications. Opportunistic infections typically occur from the second to the sixth month. During the late posttransplant period (beyond 6 months), transplantation recipients suffer from the same infections seen in the general community. Opportunistic bacterial infections seen in transplant recipients include those caused by Legionella spp., Nocardia spp., Salmonella spp., and Listeria monocytogenes. Cytomegalovirus is the most common cause of viral infections. Herpes simplex virus, varicella-zoster virus, Epstein-Barr virus and others are also significant pathogens. Fungal infections, caused by both yeasts and mycelial fungi, are associated with the highest mortality rates. Mycobacterial, pneumocystis, and parasitic diseases may also occur.

Disseminated tuberculosis after renal transplantation. A report of two cases

Disseminated mycobacterial infections occurred in two female renal graft recipients late after transplantation. In the first patient, initially presenting with fever, diagnosis was made at autopsy. Temporary defervescence following antibiotic therapy with ofloxacin possibly contributed to the fatal diagnostic delay. In the second case, body temperature was normal throughout the protracted course of the patient's illness. Her presenting symptom was rapidly increasing ascites, attributed initially to chronic liver disease. These cases demonstrate that tuberculosis remains a serious complication after renal transplantation, in particular due to its sometimes atypical clinical manifestations. Response to antibacterial therapy has to be critically evaluated in order to avoid fatal diagnostic delay.

Renal allograft tuberculosis

We present a case of miliary tuberculosis presenting as fever of unknown origin in an immunosuppressed patient following renal transplantation. Biopsy of the renal transplant revealed acid-fast bacilli histopathologically. Eye examination revealed bilateral choroidal tubercles. Recipients of kidney transplants with fever of undetermined aetiology should be investigated for tuberculosis and fundoscopy performed.

Determination of acquired immunodeficiency syndrome (AIDS) after renal transplantation

Diagnosing the acquired immunodeficiency syndrome (AIDS) in transplant recipients can be difficult due to the patient's medication-induced immunosuppressed state. We report two renal allograft recipients who acquired HIV infection at the time of transplantation and later went on to develop multiple opportunistic infections. Careful documentation of HIV antibody status of the donor and recipient, when available, the nature of immunosuppressive therapy used, the type of infections and their timing after transplantation, as well as the patient's absolute T4 lymphocyte count, T cell ratio, and B cell humoral response to infection were used as factors to distinguish between infection related to immunosuppressive therapy and that seen in HIV-induced immunodeficiency. Reduction in immunosuppressive therapy because of the HIV-related immunodeficiency state did not result in allograft rejection. Both patients died of their multiple infections. The determination of AIDS in the transplant recipient has both therapeutic and prognostic significance. This diagnosis should be considered when transplant patients develop unusual infections in relationship to their posttransplant course.

Recurrent granulomatous synovitis due to Mycobacterium kansasii in a renal transplant recipient

A 61-year-old woman received a cadaveric renal transplant in 1972 and was maintained on chronic immunosuppression. Nonspecific granulomatous synovitis of the left hand developed in 1982. After recurrence of synovitis in 1984, surgical exploration of the left hand demonstrated "rice bodies" in a region of chronic synovitis from which Mycobacterium kansasii was isolated. Despite therapy with isoniazid, rifampin, and ethambutol, to which the organism was susceptible in vitro, synovitis recurred. Recovery was completed after extensive synovectomies, decreased immunosuppression, and 24-months of therapy, with the drugs listed above; there was no evidence of mycobacterial infection at sites other than the left hand at any time. The occurrence of persistent Mycobacterium kansasii infection is distinctly unusual even in transplant recipients. In patients refractory to conventional antituberculous therapy, surgical management should be considered as an important therapeutic component.

Infection in renal transplant recipients. Current approaches to diagnosis, therapy, and prevention

Despite dramatic improvements in patient and renal allograft survival, infections continue to be an important cause of post-transplantation morbidity and mortality. Most serious infections manifest clinically as febrile diseases, and immunosuppression-induced compromised cell-mediated immunity is the basis for the predominance of infections due to opportunistic intracellular microorganisms. Diagnostic evaluation is guided by the timing of fever after transplantation, epidemiologic factors, and evidence of specific organ system involvement. Although current therapy of bacterial and parasitic infections is usually effective, the management of deep-seated fungal infections remains highly unsatisfactory. Cytomegalovirus disease, the single most important infection in some transplant centers, frequently presents as a self-limited viral syndrome; however, multiple organs may be affected. New measures for the rapid diagnosis and treatment of this viral infection hold promise. A number of recommendations have been proposed to prevent infections in renal transplant recipients; however, continued progress will depend primarily upon further refinements in immunosuppressive therapy.