Tuberculosis in maintenance dialysis patients

Tuberculous peritonitis in patients on peritoneal dialysis: a 35-year experience from a large medical center in Northern Taiwan

INTRODUCTION

Tuberculous peritonitis (TBP) is a rare but fatal complication in patients on peritoneal dialysis (PD). In this study, we aimed to determine the demographic features, clinical features, laboratory parameters, and clinical outcomes of PD patients with TBP and to clarify possible risk factors for mortality.

MATERIALS AND METHODS

We retrospectively reviewed 2084 PD patients from January 1985 to December 2019. The diagnosis of TBP was established by positive peritoneal fluid culture for Mycobacterium tuberculosis.

RESULTS

18 patients were diagnosed with TBP. The incidence was 2.029 episodes per 1000 patient-years. The most common symptom was fever (94.4%), followed by cloudy effluent (83.3%) and abdominal pain (83.3%). The average peritoneal dialysis effluent (PDE) white blood cell (WBC) count was 172.7 cells/μL. Nine patients (50%) had WBC counts lower than 100 cells/μL and 13 patients (72.2%) had neutrophilic predominant WBC counts. Acid fast stain (AFS) was positive in 7 patients (38.9%). Only 2 patients (11.1%) continued with PD after TB infection, while 10 patients (55.6%) changed to hemodialysis. Seven patients (38.9%) died within 1 year. Significant differences were observed in sex (p = 0.040), the presence of diabetes mellitus (p = 0.024), and PD catheter removal (p < 0.001) between TBP patients with and without mortality. However, none of them was a significant factor for 1-year mortality in multivariate Cox regression model.

CONCLUSION

Physicians should pay attention to the unusual presentations of peritonitis, especially if symptoms include fever or an initial low PDE WBC count. Catheter removal is not mandatory if early diagnosis and appropriate therapy are available.

Renal Transplantation in Patients With Tuberculosis: A Single-center Experience From an Endemic Region

Background

Despite being a common infection in end-stage kidney disease patients, there are no evidence-based guidelines to suggest the ideal time of transplantation in patients on antitubercular therapy (ATT). This study aimed to examine the outcome of transplantation in patients while on ATT compared with those without tuberculosis (TB).

Methods

This was a retrospective study. Renal transplant recipients transplanted while on ATT were compared with a 1:1 matched group (for age, sex, diabetic status, and type of induction agent) of patients without TB at the time of transplant. Patient outcomes included relapse of TB and graft and patient survival.

Results

There were 71 patients in each group. The mean duration for which ATT was given pretransplant was 3.8 ± 2.47 mo. The average total duration of ATT received was 12.27 ± 1.25 mo. Mortality in both the groups was similar (8.4% in the TB group versus 4.5% in the non-TB group; P = 0.49). None of the surviving patients had recurrence of TB during the follow-up. Death-censored graft survival (98.5% in the TB group versus 97% in the non-TB group; P = 1) and biopsy-proven acute rejection rates (9.86% in the TB group versus 8.45% in the non-TB group; P = 1) were also similar in both the groups.

Conclusions

Successful transplantation in patients with end-stage kidney disease on ATT is possible without any deleterious effect on patient and graft survival and no risk of disease recurrence. Multicentric prospective studies are needed.

Retrospective Analysis of Spectrum of Infections and Antibiotic Resistance Pattern in Chronic Kidney Disease Patients on Maintenance Hemodialysis in a Tertiary Care Centre in North India

Introduction

Hemodialysis patients are at risk of infections. This study examines the spectrum of infections and antibiotic resistance patterns.

Methods

We retrospectively reviewed the records of 586 hemodialysis patients from May 2018 to April 2020 in a tertiary care hospital in North India.

Results

The study identified 99 episodes of confirmed infections. Urinary tract infections were the most common type of infections (55.5%), followed by catheter-related bloodstream infections (CRBSI) (definitive 21.2%). Other infections were pneumonia (8.1%), tuberculosis (6.1%), skin and soft tissue infection (4.0%), dengue fever (3.03%), and empyema thoracis (1.0%). Overall, Escherichia coli (33.3%) was the most common organism isolated. The most frequent uropathogens recovered were Escherichia coli (54%). In confirmed CRBSI, P. aeruginosa (23.8%) and MSSA (23.8%) were the most common pathogen isolated. K. pneumonia (37.5%) was the most common pathogen in pneumonia. Uropathogens showed the highest resistance to fluoroquinolones (93.3%-100%). Pathogens isolated in CRBSI showed maximum resistance to ciprofloxacin (100%). In pneumonia, the highest resistance was seen to third-generation cephalosporins (75%-100%).

Conclusion

Though the bacterial spectrum remains the same over time, antibiotic resistance is changing in uropathogens. There is a trend of predominance of Gram-negative bacterial infections in CRBSI. Tuberculosis incidence rate was much higher than the general population. There is a need for nationwide and worldwide continuous surveillance.

Tuberculosis incidence in patients with chronic kidney disease: a systematic review and meta-analysis

OBJECTIVE

The aim of this study was to estimate global TB incidence in patients with CKD.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method was followed to perform the study. Electronic and gray literature sources were investigated for studies published between 2000 and 2021. The Joanna Briggs Institute critical appraisal checklist was used to assess the quality of the studies, and STATA version 16 was used for analysis. The I² heterogeneity test was employed to assess heterogeneity. To examine publication bias, funnel plots and Egger's regression tests were performed.

RESULTS

A total of 104 studies with a sample size of 1,548,774 were included. TB incidence in patients with CKD ranges from 60 per 100,000 in the UK to 19,270 per 100,000 in China. The pooled TB incidence was estimated as 3718 per 100,000 (95%CI; 3024, 4411). Higher pooled TB incidence was found in the African region (9952/100,000, 95%CI; 6854, 13,051), followed by the South-East Asian (7200/100,000, 95%CI; 4537, 9863) and Eastern Mediterranean (5508/100,000, 95%CI; 3470, 7547) regions. In particular, patients on hemodialysis (5611/100,000) and on peritoneal dialysis (3533/100,000) had higher incidence of TB than did renal transplantation patients (2700/100,000) and patients with predialysis CKD (913/100,000). Furthermore, extrapulmonary TB (2227/100,000) was more common than pulmonary TB (1786/100,000).

CONCLUSION

This study identifies high TB incidence in patients with CKD with regional disparities. Thus, the authors recommend active TB screening in this group of individuals.

The Risk of Tuberculosis Infection in Non-dialysis Chronic Kidney Disease Patients

Background: Patients with chronic kidney disease (CKD) receiving maintenance renal replacement therapy are at higher risk of tuberculosis (TB) infection. The risk of TB infection in CKD patients not receiving dialysis is unknown.

Aim: We conduct this study to test the hypothesis that TB infection is negatively correlated to renal function.

Design: Non-dialysis CKD stage 1–5 patients, admitted in China Medical University Hospital from January of 2003 to May of 2014, were enrolled in this study and were prospectively followed up to the diagnosis of TB, death, loss to follow-up, or December 2014. The risk factors of TB infection were analyzed using competing-risks regression analysis with time-varying covariates. The initiation of dialysis and patients' death were considered as competing events. Patients' estimated glomerular filtration rate (eGFR) and body mass index (BMI) were recorded at enrollment.

Results: They were followed-up for a median duration of 1.4 years. Of the 7221 patients, TB infection was identified in 114 patients. Higher eGFR was associated with lower risk of TB infection (P < 0.01). The adjusted subdistribution hazard ratio (aSHR) was 0.82 [95% confidence interval (CI), 0.72 to 0.94] for every 5 ml/min/1.73 m² increase in eGFR. In addition, higher BMI (p = 0.01) was associated with a lower risk of TB infection and the aSHR was 0.91 (95% CI, 0.85 to 0.98) for every 1 kg/m² increase in BMI.

Conclusion: Renal function and body mass index are independently associated with the risk of tuberculosis infection in patients with chronic kidney disease not receiving dialysis.

Tuberculosis treatment delay and nosocomial exposure remain important risks for patients undergoing regular hemodialysis

BACKGROUND AND OBJECTIVE

Studies have reported an increased tuberculosis (TB) incidence among patients with end-stage renal disease (ESRD). This nationwide nested Case-control study investigated the risk of active TB due to nosocomial exposure and its correlation with the delay in TB treatment in hemodialysis patients.

METHODS

Adult (aged ≥20 years) patients with incident ESRD over 2000-2010 were identified from Taiwan National Health Insurance Research Database; 2331 patients with incident active TB (Case) were matched with 11,655 patients without TB (control) by age, sex, year of ESRD onset, Charlson comorbidity index, chronic obstructive pulmonary disease, and diabetes mellitus, at a 1:5 case-to-control ratio.

RESULTS

Compared with the control group, the Case group had greater nosocomial exposure to index patients with pulmonary TB (2.36 vs. 0.11 month of exposure, p < 0.001). Nosocomial exposure increased active TB risk (adjusted odds ratio [OR; 95% confidence interval, CI]: 1.60 [1.55-1.66] per month of exposure), particularly when the exposure time was either within 6 months before the index case was diagnosed or 6-15 months before the ESRD patient became an incident active TB case. For patients with active TB, cough-related medication prescriptions (proxy for cough symptoms) exponentially increased over 6 months before TB treatment.

CONCLUSION

Nosocomial exposure attributed to delay in the diagnosis of index pulmonary TB is important in TB transmission among patients undergoing regular hemodialysis. Additional studies investigating how TB can be diagnosed and treated early are warranted.

SUMMARY AT A GLANCE

Our study revealed that nosocomial exposure, attributed to delay in pulmonary TB diagnosis, is important in TB transmission among patients undergoing regular hemodialysis. Strategies to diagnose and treat TB early are crucial to infection control, and they warrant further investigations.

CD4 response of QuantiFERON-TB Gold Plus for positive consistency of latent tuberculosis infection in patients on dialysis

A significantly negative reversion in the QuantiFERON-TB Gold In-tube (QFT-GIT) test is reported in patients on dialysis, which makes the results unreliable. The CD4 and CD8 responses of the QFT-Gold plus (QFT-Plus) may have better positive consistency, but this needs to be investigated. We enrolled dialysis patients with baseline positive QFT-GIT₀ results and conducted two rounds of follow-up paired QFT-GIT_1&2 and QFT-Plus_1&2 tests at an interval of 6 months. The positive consistency, concordance, and discordance of the QFT results were analyzed. A total of 236 patients on dialysis were screened, and 73 participants with positive QFT-GIT₀ results were enrolled. The baseline QFT-GIT₀ response was higher in the 1st QFT-Plus₁(+) group than in the QFT-Plus₁(-) group, but insignificantly different between the 1st QFT-GIT₁(+) and QFT-GIT₁(-) groups. The two assays had good correlation when concurrently tested. Fifty-three subjects completed a second round of the QFT-GIT₂ and QFT-Plus₂. Persistent positivity was higher with the QFT-Plus₂ (81.8%) than with the QFT-GIT₂ (58.8%, p = 0.040). The QFT-GIT₁ and QFT-Plus₁ CD4 responses were higher in patients with persistent positivity than in those with negative reversion, whereas the difference of the QFT-Plus TB1 and TB2 data, representative of the CD8 response, were similar between positive persistence and negative reversion. In conclusion, the QFT-Plus provides more reliable positive consistency than does the QFT-GIT. The CD4 interferon-γ response might play a role in maintaining positivity of LTBI.

Intestinal tuberculosis in a patient with end-stage renal disease on hemodialysis: A case report

RATIONALE

Intestinal tuberculosis (TB) is rarely seen in patients with end-stage renal disease (ESRD). We report an intestinal TB case with a clinical presentation similar to that of colon cancer in a patient with ESRD on hemodialysis.

PATIENT CONCERNS

A 49-year-old man presented with a 3-month history of general weakness and anorexia. He had been treated for stage 5 chronic kidney disease (CKD) due to diabetic nephropathy for the last 3 years. His blood urea nitrogen and serum creatinine levels were 96.9 and 8.1 mg/dL, respectively, at the time of admission; azotemia was accompanied by severe anemia, hypoalbuminemia, hyperkalemia, and metabolic acidosis. Hemodialysis was initiated for suspected exacerbation of uremia; however, intermittent fever, night sweats, and abdominal discomfort persisted.

DIAGNOSES

Abdominal computed tomography (CT) and whole-body F-fluorodeoxyglucose positron emission tomography were indicative of ascending colon cancer with lymph node metastases. However, colonoscopy with biopsy revealed the formation of submucosal caseating granuloma and acid-fast bacillus.

INTERVENTIONS

We initiated quadruple therapy with isoniazid, rifampicin, pyrazinamide, and ethambutol. The patient continued the quadruple regimen for the first 2 months before switching to dual therapy and received anti-TB medications for a total of 12 months.

OUTCOMES

After 9 months of standard anti-TB chemotherapy, polypoid residual lesions were noted during follow-up colonoscopy. Laparoscopy-assisted ileocecal resection was performed. No findings suggestive of recurrence of colonic TB were observed on follow-up abdominal CT at 6 months after discontinuation of anti-TB medications.

LESSONS

If non-specific uremic symptoms persist in patients with advanced CKD, the possibility of extrapulmonary TB such as intestinal TB must be considered. Also, in patients with radiologic suspicion of colon cancer, endoscopy with biopsy should be performed promptly to exclude colonic TB with similar clinical manifestations.

Uncommon Association of Tuberculous Dactylitis and Cutaneous Polyarteritis Nodosa in a Hemodialysis Patient

Tuberculous dactylitis, defined as the infection of the metacarpals, metatarsals, or phalanges of the hands or feet, is an uncommon manifestation of extrapulmonary tuberculosis. It is mainly seen in pediatric populations, especially those less than 6 years old. Here, we present a case of tuberculous dactylitis in an elderly patient with end-stage renal disease on hemodialysis. Moreover, our patient also developed generalized nodular lesions during hospitalization. Skin biopsy was consistent with cutaneous polyarteritis nodosa, which is a rare association with tuberculosis. She was treated with antituberculous drugs with significant improvement in both cutaneous nodules and dactylitic lesions.

End-stage Renal Disease and Risk of Active Tuberculosis: a Nationwide Population-Based Cohort Study

BACKGROUND

The converging epidemics of tuberculosis (TB) and end-stage renal disease (ESRD) have generated a significant public health burden, however, previous studies have been limited to a small number of patients. This nationwide cohort study aimed to assess the rate of developing active TB among patients receiving dialysis for ESRD.

METHODS

The Korean national health insurance database was used to identify patients receiving dialysis for new-onset ESRD during 2004-2013, who were propensity score matched to an equivalent number of non-dialysis subjects from the general population. The incidences of active TB in the ESRD and control cohorts were calculated for 2004-2013, and multivariable Cox proportional hazards model was used to evaluate the ESRD-related risk of active TB.

RESULTS

During 2004-2013, 59,584 patients received dialysis for newly diagnosed ESRD. In the dialysis and control cohorts, 457 (0.8%) and 125 (0.2%) cases of active TB were detected, respectively. Patients with ESRD were associated with a significantly higher risk of active TB compared to the controls (incidence rate ratio, 4.80). The ESRD cohort had an independently elevated risk of active TB (adjusted hazard ratio, 4.39; 95% confidence interval, 3.60-5.37).

CONCLUSION

We found that patients receiving dialysis for ESRD had an elevated risk of active TB. These results highlight the need for detailed and well-organised guidelines for active TB screening among patients with ESRD.

Epidemiology, detection, and management of tuberculosis among end-stage renal disease patients

Tuberculosis (TB) remains an important problem among end-stage renal disease (ESRD) patients. We reviewed the epidemiology of TB and ESRD, investigations of TB exposures in US dialysis facilities, and published guidelines to inform screening and treatment practices among US ESRD patients. Compared to TB in the general population, ESRD patients have 6-25-fold higher TB incidence rates, and mortality during treatment is 2-3-fold higher. Most TB cases among ESRD patients (~90%) occur among non-US-born persons, and an analysis of genotyping data suggests that 80% of all cases result from latent TB infection (LTBI) reactivation. Published TB contact investigations in dialysis facilities have reported cases among ESRD patients and healthcare workers. However, transmission of TB is rare: there were no reports of secondary cases of TB because of exposure to an index-case patient and there were few TB infections, which was demonstrated by low occurrence of newly positive tuberculin skin tests (12%-16%) and conversions (8%-17%) among contacts. Targeted TB education, screening, and treatment for ESRD patients at highest risk for TB exposure (eg, non-US-born persons), using interferon-gamma release assays and short course LTBI regimens (ie, isoniazid-rifapentine weekly for 12 weeks or rifampin daily for 4 months) may be an effective overall strategy for reducing TB burden in ESRD patients.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, solid organ transplantation and, possibly, sexual contact and whole blood transfusion. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, sexual contact, whole blood transfusion and solid organ transplantation. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

Rediscovering Beta-2 Microglobulin As a Biomarker across the Spectrum of Kidney Diseases

There is currently an unmet need for better biomarkers across the spectrum of renal diseases. In this paper, we revisit the role of beta-2 microglobulin (β₂M) as a biomarker in patients with chronic kidney disease and end-stage renal disease. Prior to reviewing the numerous clinical studies in the area, we describe the basic biology of β₂M, focusing in particular on its role in maintaining the serum albumin levels and reclaiming the albumin in tubular fluid through the actions of the neonatal Fc receptor. Disorders of abnormal β₂M function arise as a result of altered binding of β₂M to its protein cofactors and the clinical manifestations are exemplified by rare human genetic conditions and mice knockouts. We highlight the utility of β₂M as a predictor of renal function and clinical outcomes in recent large database studies against predictions made by recently developed whole body population kinetic models. Furthermore, we discuss recent animal data suggesting that contrary to textbook dogma urinary β₂M may be a marker for glomerular rather than tubular pathology. We review the existing literature about β₂M as a biomarker in patients receiving renal replacement therapy, with particular emphasis on large outcome trials. We note emerging proteomic data suggesting that β₂M is a promising marker of chronic allograft nephropathy. Finally, we present data about the role of β₂M as a biomarker in a number of non-renal diseases. The goal of this comprehensive review is to direct attention to the multifaceted role of β₂M as a biomarker, and its exciting biology in order to propose the next steps required to bring this recently rediscovered biomarker into the twenty-first century.

Comparison of QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for diagnosis of latent tuberculosis in haemodialysis (HD) patients: a meta-analysis of κ estimates

Diagnosis of latent tuberculosis infection (LTBI) is a concern in haemodialysis (HD) patients. Many studies have compared QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for detecting LTBI and reported the κ statistic of agreement between QFT-GIT and TST in HD patients. The present study aimed to systematically review this literature and conduct meta-analysis of individual studies that estimated the κ between QFT-GIT with TST among HD patients. All relevant published studies that were available as full-text were obtained by searching Medline (1950), Web of Sciences (1945), Scopus (1973) through May 2016. The κ was re-estimated from the individual studies and pooled using random effect meta-analysis. Subgroup analysis and meta-regression were applied to evaluate the effect of Bacillus Calmette-Guérin (BCG) vaccination, TST cut-off points, quality of studies, sample size and age on variation of κ estimate. Eight studies involving 901 HD patients were included in meta-analysis. The pooled κ estimate was 0·28 (I 2 = 18·4%, P = 0·239, 95% confidence intervals 0·22-0·34). The discordance of TST-/QFT-GIT+ was more than TST+/QFT-GIT-. History of BCG vaccination, TST cut-off points and age are related to variation of κ estimates. TST and QFT-GIT are not comparable in detecting LTBI in HD patients. The higher TST-/QFT-GIT+ ratio compared with TST+/QFT-GIT- ratio, may indicate the superiority of QFT-GIT over TST for detection LTBI in HD patients.

Effect of pulmonary tuberculosis on clinical outcomes of long-term dialysis patients: Pre- and post-DOTS implementation in Taiwan

BACKGROUND AND OBJECTIVE

The link between tuberculosis (TB) and dialysis is known; however, the impact of TB on the clinical outcomes remains to be elucidated. This study aims to determine the clinical consequences of pulmonary TB among patients under long-term dialysis.

METHODS

A retrospective propensity-scores matched (1:4) cohort study was conducted by retrieving patient data for pulmonary TB after long-term dialysis commencement from the Taiwan National Health Insurance Research Database between 1999 and 2013. Patients with TB (n = 1993) or without TB (n = 7972) were compared for 3-year morbidity and mortality. The effect of Directly Observed Treatment, Short-Course (DOTS) implementation was also evaluated. Cox proportional hazards models were used to determine adjusted hazard ratios (HRs).

RESULTS

TB patients had a significantly higher risk of mortality than non-TB patients even after multivariate adjustment (HR: 1.48; 95% CI: 1.36-1.60; P < 0.001). DOTS implementation reduced the risk of some morbidities such as pneumonia, hospitalization and intensive care unit stay >7 days, but not inotropic agent usage, ventilator therapy >21 days and mortality in TB patients. In pulmonary TB patients with treatment duration ≥180 days, DOTS implementation also lowered the risk of TB relapse (HR: 0.33; 95% CI: 0.19-0.55; P < 0.001), irrespective of treatment duration (180-224 or ≥225 days).

CONCLUSION

Pulmonary TB increases the risk of morbidity and mortality in dialysis patients; DOTS implementation reduces some morbidities and TB relapse. Continuing DOTS implementation should be encouraged to improve clinical outcomes in dialysis patients.

Predictive value of the tuberculin skin test and QuantiFERON-tuberculosis Gold In-Tube test for development of active tuberculosis in hemodialysis patients

BACKGROUND

Hemodialysis (HD) patients are at increased risk of reactivation of latent tuberculosis infection (LTBI) compared with the general population. QuantiFERON-TB Gold (QFT-G) for LTBI detection is more promising than tuberculin skin test (TST) in HD patients.

AIM

In our study, we evaluated the value of the TST and QFT-G In-Tube (QFG-IT) test in the development of active tuberculosis (TB), in the HD patients, and in healthy controls.

METHODS

The study enrolled 95 HD patients and ninety age-matched, healthy controls. The TST and QFG-IT were performed. All the subjects were followed up 5 years for active TB disease.

RESULTS

Compared to the healthy controls, a high prevalence of LTBI was found in the HD patients by QFG-IT (41% vs. 25%). However, no significant difference was detected by TST (32% vs. 31%). Four HD patients and one healthy control progressed to active TB disease within the 5-year follow-up. For active TB discovered subjects, QFG-IT was positive in all, but TST was positive in two (one patient and one healthy control). In HD patients; sensitivity, specificity, positive and negative predictive values of QFG-IT, and TST for active TB was 100% and 25%, 62% and 67%, 10%, and 3%, and 100% and 95%, respectively. Receiver operating curve analysis revealed that the results are significantly different (P = 0.04).

CONCLUSION

QFG-IT test is a more useful diagnostic method than TST for detecting those who will progress to active TB in HD patients.

Epidemiology of tuberculosis cases with end-stage renal disease, California, 2010

BACKGROUND/AIMS

Few studies have compared population-based tuberculosis (TB) incidence rates by end-stage renal disease (ESRD) status. No studies have compared TB genotypes by ESRD status to determine whether TB disease resulted from recent transmission or reactivation of latent TB infection (LTBI). We calculated TB incidence rates and compared demographic and clinical characteristics and genotypes among TB cases by ESRD status.

METHODS

This analysis was based on prospective surveillance for TB cases during 2010 in California. Clustered genotype was defined as ≥2 culture-positive TB cases with matching genotypes in the same county. The χ(2) or Wilcoxon rank-sum test was used to compare variables.

RESULTS

During 2010, 83 TB cases with ESRD and 2,244 cases without ESRD were reported in California; TB incidence rates were 110.3/100,000 and 6.0/100,000, respectively. ESRD case patients versus patients without ESRD were more likely to be older (median age 66 vs. 49 years; p < 0.001), foreign-born persons who had arrived in the USA >5 years before TB diagnosis (97 vs. 75%; p < 0.001) and dead at TB diagnosis (7 vs. 2%; p = 0.01). ESRD patients were less likely to have a positive tuberculin skin test (50 vs. 80%; p < 0.001), positive acid-fast bacilli sputum smears (33 vs. 53%; p = 0.01) and cavities on chest radiography (6 vs. 21%; p = 0.01). No differences in proportions of clustered TB genotypes were detected (20 vs. 23%; p = 0.54).

CONCLUSIONS

Rates of TB are 18 times higher in California's ESRD population, and TB disease likely occurred due to LTBI reactivation because few patients had clustered genotypes. Efforts to prevent TB among ESRD patients may require the use of newer diagnostic tests and promotion of LTBI treatment.

Tuberculosis in haemodialysis patients: A single centre experience

We prospectively followed-up new patients of tuberculosis while on maintenance hemodialysis at a State Government-run tertiary care institute. Between 2000 and 2010, 1237 new patients were initiated on maintainence hemodialysis. The number of patients diagnosed with tuberculosis after initiation of hemodialysis was 131 (10.5% of 1237). The age was 46.4 ± 10.4 (range 8-85) years and there were 90 (68.7%) males. The number of patients diagnosed with tuberculosis on the basis of organ involvement were: Pulmonary-60, pleural effusion-31, lymph node-21, meningitis-8, pericardial effusion-7, peritoneum-2, latent tuberculosis-2. The incidence of tuberculosis in hemodialysis was found to be 105.9 per 1000 patient years. Male gender, diabetes mellitus, past history of tuberculosis, mining as an occupation, low serum albumin, and duration of hemodialysis more than 24 months, and unemployment were found to be significant risk-factors on univariate analysis.

Extra-pulmonary tuberculosis infection in the dialysis patients with end stage renal diseases: case reports and literature review

The diagnosis of extra-pulmonary tuberculosis (TB) seems relatively difficult due to the absence of specific symptoms and signs in patients on peritoneal dialysis or hemodialysis. We report four cases of extra-pulmonary tuberculosis on dialysis, with two cases on peritoneal dialysis and two cases on hemodialysis. The presentations, therapy, and outcomes of TB infection in these patients were reviewed. Otherwise, the English literature published in the PubMed database associating extra-pulmonary tuberculosis on dialysis over the last three decades is reviewed. A total of 61 studies containing 70 cases were included. The most common primary disease was diabetic nephropathy (22.86%, 16/70). The peritoneum (31.42%, 22/70), bone (21.42%, 15/70), and lymph node (20%, 14/70) were the most frequently infected. Single organ infection was common (90%, 63/70). Fever (58.57%, 41/70), pain (35.71%, 25/70), and enlarged lymph node (20%, 14/70) were the most common symptoms. Biopsy (67.14%, 47/70) and culture (40%, 28/70) provided most reliable methods for clear diagnosis of tuberculosis. The combined treatment of isoniazid, rifampicin, pyrazinamide, and ethambutol (44.29%, 31/70) was the most common therapy. The majority of patients improved (82.86%, 58/70); however, 12 cases got worse (17.14%), with 10 of them dying (14.29%). Physicians should be aware of the non-specific symptoms and location of infection, and consider tuberculosis in their differential diagnoses in dialysis patients presenting with symptoms such as fever, pain, and weight loss.

Heparin-binding haemagglutinin, a new tool for the detection of latent Mycobacterium tuberculosis infection in hemodialysis patients

Background

Patients with end-stage renal disease (ESRD) and latently infected with Mycobacterium tuberculosis (LTBI) are at higher risk to develop tuberculosis (TB) than healthy subjects. Interferon-gamma release assays (IGRAs) were reported to be more sensitive than tuberculin skin tests for the detection of infected individuals in dialysis patients.

Methods

On 143 dialysis patients prospectively enrolled, we compared the results from the QuantiFERON®-TB Gold assay (QFT), to those of an IGRA in response to in vitro stimulation of circulating mononuclear cells with the mycobacterial latency antigen Heparin-Binding Haemagglutinin purified from Mycobacterium bovis BCG (native HBHA, nHBHA).

Results

Seven patients had a past history of active TB and 1 had an undetermined result with both IGRAs. Among the other 135 patients, 94 had concordant results with the QFT and nHBHA-IGRA, 40.0% being negative and therefore not latently infected, and 29.6% being positive and thus LTBI. Discrepant results between these tests were found for 36 patients positive only with the nHBHA-IGRA and 5 only with the QFT.

Conclusions

The nHBHA-IGRA is more sensitive than the QFT for the detection of LTBI dialysis patients, and follow-up of the patients will allow us to define the clinical significance of discrepant results between the nHBHA-IGRA and the QFT.

Increased risk of active tuberculosis following acute kidney injury: a nationwide, population-based study

BACKGROUND

Profound alterations in immune responses associated with uremia and exacerbated by dialysis increase the risk of active tuberculosis (TB). Evidence of the long-term risk and outcome of active TB after acute kidney injury (AKI) is limited.

METHODS

This population-based-cohort study used claim records retrieved from the Taiwan National Health Insurance database. We retrieved records of all hospitalized patients, more than 18 years, who underwent dialysis for acute kidney injury (AKI) during 1999-2008 and validated using the NSARF data. Time-dependent Cox proportional hazards model to adjust for the ongoing effect of end-stage renal disease (ESRD) was conducted to predict long-term de novo active TB after discharge from index hospitalization.

RESULTS

Out of 2,909 AKI dialysis patients surviving 90 days after index discharge, 686 did not require dialysis after hospital discharge. The control group included 11,636 hospital patients without AKI, dialysis, or history of TB. The relative risk of active TB in AKI dialysis patients, relative to the general population, after a mean follow-up period of 3.6 years was 7.71. Patients who did (hazard ratio [HR], 3.84; p<0.001) and did not (HR, 6.39; p<0.001) recover from AKI requiring dialysis had significantly higher incidence of TB than patients without AKI. The external validated data also showed nonrecovery subgroup (HR = 4.37; p = 0.049) had high risk of developing active TB compared with non-AKI. Additionally, active TB was associated with long-term all-cause mortality after AKI requiring dialysis (HR, 1.34; p = 0.032).

CONCLUSIONS

AKI requiring dialysis seems to independently increase the long-term risk of active TB, even among those who weaned from dialysis at discharge. These results raise concerns that the increasing global burden of AKI will in turn increase the incidence of active TB.

Increased risk of tuberculosis in patients with end-stage renal disease: a population-based cohort study in Taiwan, a country of high incidence of end-stage renal disease

This nationwide population-based cohort study investigated the risk of tuberculosis (TB) in patients with end-stage renal disease (ESRD) and receiving dialysis. The evaluations included 4131 incident ESRD patients receiving dialysis and 16,524 age- and gender-matched controls, recruited between 1998 and 2009. We used Cox proportional hazards regression analysis to measure the association between TB and ESRD. Compared to the controls, the ESRD cohort had a significantly higher risk of TB within 1 year [incident rate ratio (IRR) 4.13], and 1-2 years (IRR 2.12), of occurrence of ESRD. The Cox proportional hazards model revealed that ESRD [hazard ratio (HR) 2.40], age >65 years (HR 2.41), male sex (HR 1.94), diabetes mellitus (HR 1.36), silicosis (HR 7.70) and chronic obstructive pulmonary disease (HR 1.61) are independent risk factors for TB. Patients with ESRD are associated with an increased risk of TB, and should thus be monitored more carefully for TB, especially within 2 years of onset of ESRD.

Risk stratification of latent tuberculosis defined by combined interferon gamma release assays

BACKGROUND

Most individuals infected with Mycobacterium tuberculosis develop latent tuberculosis infection (LTBI). Some may progress to active disease and would benefit from preventive treatment yet no means currently exists to predict who will reactivate. Here, we provide an approach to stratify LTBI based on IFN-γ responses to two antigens, the recombinant Early-Secreted Antigen Target-6 (rESAT-6) and the latency antigen Heparin-Binding Haemagglutinin (HBHA).

METHODS

We retrospectively analyzed results from in-house IFN-γ-release assays with HBHA (HBHA-IGRA) and rESAT-6 (rESAT-6-IGRA) performed during a 12-year period on serial blood samples (3 to 9) collected from 23 LTBI subjects in a low-TB incidence country. Both the kinetics of the absolute IFN-γ concentrations secreted in response to each antigen and the dynamics of HBHA/rESAT-6-induced IFN-γ concentrations ratios were examined.

RESULTS

This analysis allowed the identification among the LTBI subjects of three major groups. Group A featured stable HBHA and rESAT-6-IGRA profiles with an HBHA/rESAT-6 ratio persistently higher than 1, and with high HBHA- and usually negative rESAT-6-IGRA responses throughout the study. Group B had changing HBHA/rESAT-6 ratios fluctuating from 0.0001 to 10,000, with both HBHA and rESAT-6 responses varying over time at least once during the follow-up. Group C was characterized by a progressive disappearance of all responses.

CONCLUSIONS

By combining the measures of IFN-γ concentrations secreted in response to an early and a latency antigens, LTBI subjects can be stratified into different risk groups. We propose that disappearing responses indicate cure, that persistent responses to HBHA with HBHA/rESAT-6 ratios ≥ 1 represent stable LTBI subjects, whereas subjects with ratios varying from >1 to <1 should be closely monitored as they may represent the highest-risk group, as illustrated by a case report, and should therefore be prioritized for preventive treatment.

The affecting factors and comparison of tuberculin skin test in peritoneal dialysis and hemodialysis patients

Compared with the general population, patients with chronic renal failure have increased tuberculosis (TB) prevalence and mortality rates. In this study, we aimed to investigate tuberculin skin test (TST) positivity rates in hemodialysis (HD) and peritoneal dialysis (PD) patients and the factors influencing TST positivity. Ninety-two HD patients and 44 PD patients who had been on HD and PD treatment for at least 3 months were recruited into the study. TST was administered in all patients. Positivity was defined as an induration diameter >10 mm. At least 5 mm of induration following skin testing together with a chest radiography indicating previous infection was defined as latent TB infection. TST positivity rates, diameter of TST indurations, and serum albumin levels in HD patients were higher than the PD patients. TST induration size was not correlated with any other parameters in both HD and PD groups. TST-positive patients had higher albumin levels and lower leukocyte count than the TST-negative patients. In TST-positive patients, albumin level was correlated with the duration of dialysis but TST induration size was not correlated with the lymphocyte count and albumin level. In our study, TST positivity of patients was found in 30.4% of HD patients, 9% of PD patients, and 23.5% of total patients. It is still recommended to use TST for the screening test of TB. We found a significant relationship between TST and albumin level. It should be remembered that TST response may be lower in PD patients, especially in cases in which TB is suspected.

Risk of tuberculosis in dialysis patients: a nationwide cohort study

BACKGROUND

The ability to identify individuals at increased risk of developing tuberculosis (TB) has important implications for public health policy and patient care. We conducted a general population historical cohort study in all Australian States and Territories to establish the risk of TB arising in people on chronic hemo- or peritoneal dialysis.

METHODOLOGY/PRINCIPAL FINDINGS

Cases of TB disease in patients receiving chronic dialysis were identified by record linkage using the Australia & New Zealand Dialysis and Transplant Registry (ANZDATA) and State and Territory TB notification databases 2001 to 2006. Main outcome measure was the relative risk of TB in people on dialysis, adjusted for TB incidence in country of birth, sex, age and indigenous status. A total of 6,276 cases of active TB were reported among 19,855,283 people living in Australia between 2001 and 2006. Among 14,506 patients on dialysis, 37 had a notification for TB disease after commencing dialysis, of whom 28 were culture positive. The incidence of TB was 66.8/100,000/year (95% CI 47.7 to 93.2) among people on dialysis and 5.7/100,000/year (95% CI 5.5 to 5.8) in the general population. The adjusted relative risk (aRR) of TB in people on dialysis was 7.8 (95% CI 3.3 to 18.7), and the aRR of culture positive TB was 8.6 (95% CI 3.9 to 19.3).

CONCLUSIONS/SIGNIFICANCE

Patients on dialysis are at increased risk of TB. The final decision to screen for, and to treat, LTBI in individual dialysis patients will be influenced by a cumulative assessment of the risk of reactivation of TB and by assessment of risk factors for adverse effects of treatment.

High prevalence of latent tuberculosis infection in dialysis patients using the interferon-gamma release assay and tuberculin skin test

BACKGROUND AND OBJECTIVES

Patients in ESRD on hemodialysis with latent tuberculosis (TB) infection have 10 to 25 times the risk of reactivation into active disease compared with healthy adults. This study investigates the prevalence of latent TB infection in dialysis patients from a country with an intermediate burden of TB and its associated risk factors using the QuantiFERON-TB Gold in-tube test (QGIT) and the tuberculin skin test (TST).

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This was a prospective, cross-sectional study performed at a medical center in Taiwan on dialysis patients. Each patient underwent QGIT, two-step TST using 2 tuberculin units (TU) of PPD RT-23, a chest x-ray to exclude active TB, and an interview to determine TB risk factors.

RESULTS

Ninety-three of 190 eligible patients were enrolled: 35 men and 58 women. 64.8% were vaccinated with the Bacille-Calmette-Guérin (BCG) vaccination. Overall, 34.4% were positive by QGIT and 10.8% were indeterminate. Using a 10-mm TST cutoff, 53.9% were positive. There was poor correlation between TST and QGIT at any TST cutoff criteria. There was a significant increasing trend of QGIT positivity with age in those younger than 70 years, and, conversely, a decreasing trend of TST reactivity with age. Significant risk factors for QGIT positivity included age and past TB disease.

CONCLUSIONS

This study shows a high prevalence of latent TB infection in dialysis patients in a country with an intermediate burden of TB. QGIT in dialysis patients correlated better than TST with the risk of TB infection and past TB disease.

Tuberculous spondylitis in patients with end-stage renal disease undergoing chronic hemodialysis therapy — Report of two cases

Tuberculous spondylitis is more common in patients with chronic renal failure who receive hemodialysis because of their abnormal T-cell-mediated immunity. It frequently poses both diagnostic and therapeutic challenges. We describe two cases of tuberculous spondylitis in patients undergoing chronic hemodialysis therapy. They are IFN-γ assay diagnosed (QuantiFERON-TB Gold) and conservatively treated. Our cases suggest that IFN-γ assays equip clinicians with more accurate tools for tuberculosis control. A combination of T-SPOT.TB testing and MRI assessment may be the accurate method to diagnose tuberculous spondylitis in patients with end-stage renal disease.

Tuberculosis of the breast in a patient undergoing hemodialysis

A 61-year-old female patient with diabetes undergoing maintenance hemodialysis presented with fever and swelling of her right breast. She had been unresponsive to nonspecific antimicrobial therapies. Breast tuberculosis and tuberculous lymphadenitis were diagnosed by excision biopsy and tissue culture. A combination antituberculous treatment including isoniazid, rifampin, ethambutol, and pyrazinamide was started and resulted in the remission of the lesions by the end of the first month of therapy.

Incidence of fever of unknown origin and subsequent antitubercular medications in hemodialysis patients: a two-year prospective study

BACKGROUND

Hemodialysis (HD) patients are susceptible to atypical tuberculosis (TB), especially among patients presenting with fever of unknown origin (FUO), because of their impaired cellular immunity. Diagnostic trials of anti-TB drugs are therefore recommended in some TB endemic countries, including Japan, though clinical evidence for this therapy is scarce.

METHODS

We prospectively collected data for incident cases of clinical FUO for two years in 78 of 169 dialysis facilities in Aichi prefecture, located in central Japan. Clinical FUO was defined as sustained fever without any localizing signs and no infiltration on chest x-rays after a one-week antibiotic trial. The baseline characteristics, subsequent body temperatures on the days of HD therapy, and names of antibiotics including anti-TB drugs with the durations of medication were reported until fever alleviation or fever sustainment for over eight weeks.

RESULTS

We identified 15 newly developed clinical FUO patients among 8,125 HD patients. The incidence rate was estimated to be 92 (95% CI, 26-158) per 100,000 person-years. This corresponds to 244 cases per year among 264,473 HD patients in Japan. Anti-TB drugs were secondarily prescribed in 8 of 15 clinical FUO patients (53%). No improved fever alleviation was observed when anti-TB drugs were secondarily prescribed compared with cases in which other antibiotics were preferred.

CONCLUSION

We investigated the incidence of FUO in HD patients and found that the rate was not very high, whereas anti-TB drugs were frequently used for FUO cases. The efficacy of this diagnostic therapy should be elucidated in large-scale studies.

A case of tuberculous peritonitis in a hemodialysis patient with high serum soluble interleukin-2 receptor and CA-125 levels

A hemodialysis patient with tuberculous peritonitis with hypercalcemia and high serum soluble interleukin-2 receptor (sIL-2R) and CA-125 levels is reported. An 82-year-old woman who had been on hemodialysis therapy for 6 years was admitted to our hospital for evaluation and treatment of hypercalcemia. Laboratory examination and radiologic studies revealed markedly increased serum sIL-2R and CA-125 levels and exudative ascites, with high levels of adenosine deaminase (ADA) and CA-125, which was suggestive of malignancy or tuberculosis. She was finally diagnosed as having tuberculous peritonitis based on positivity for Mycobacterium tuberculosis in ascitic fluid. The ascites subsided with normalization of hypercalcemia and a marked decrease in serum sIL-2R and CA-125 levels in response to anti-tuberculosis treatment. This case indicates that serum sIL-2R and CA-125 levels can rise to levels suggestive of malignancy in tuberculous peritonitis, and that they can be used to monitor the response to anti-tuberculosis treatment.

Tuberculosis in children undergoing hemodialysis

Tuberculosis (TB) remains a public health problem in Tunisia. Its incidence is higher in immunocompromised hosts than in the general population. In children and during hemodialysis, TB is characterized by the frequency of extrapulmonary localizations and diagnostic difficulties. The aim of this retrospective study is to evaluate the incidence of TB in Tunisian children undergoing hemodialysis and to determine its clinical features as well as the results of chemotherapy.

Validity of interferon-γ-release assays for the diagnosis of latent tuberculosis in haemodialysis patients

Haemodialysis patients are at higher risk of developing active tuberculosis (TB) infection. However, tuberculin skin tests (TST) have limitations and the diagnostic usefulness of interferon-γ-release assays (IGRAs) remains unclear in immunocompromised hosts including haemodialysis patients. Haemodialysis patients were enrolled from a dialysis centre in Korea, an intermediate TB-burden country with a high bacille Calmette-Guérin (BCG) vaccination rate. The QuantiFERON-Gold TB In tube test (QFT) and the T-SPOT TB test (TSPOT) were performed, along with the TST. We stratified patients to low- and high-risk groups, according to the risk factors for latent TB. Association between each of the three diagnostic tests and the risk of latent TB was analysed. One hundred and sixty-seven patients were enrolled. The positive rates for the TST, the QFT and TSPOT were 23.5, 45.9 and 60.4%, respectively. Previous BCG vaccination increased the TST-positive rate in the low-risk group (OR 4.438), whereas it affected neither QFT nor TSPOT. The positive QFT rates were 41.2 and 62.5% in the low- and high-risk groups, respectively. The QFT was associated with the high-risk group (OR 2.578), whereas the TST was not. The positive TSPOT rates were 58.9 and 65.7% in the low- and high-risk groups, respectively. The frequency of indeterminate results was higher for the QFT (12.6%) compared with the TSPOT (4.8%). In conclusion, the IGRAs can be useful for the diagnosis of latent TB infection in haemodialysis patients.

Extrapulmonary Tuberculosis in Chronic Hemodialysis Patients

BACKGROUND

The incidence of extrapulmonary tuberculosis is higher in dialysis than general population. The aim of the study was to characterize clinical picture in dialysis patients, who developed extrapulmonary tuberculosis.

METHODS

We retrospectively investigated the hemodialysis patients with extrapulmonary tuberculosis. 2208 hemodialysis patients were reviewed for extrapulmonary tuberculosis from October 1986 to January 2001.

RESULTS

Seventeen patients (10 male, 7 female) were enrolled. The mean age was 57.4 +/- 12.4 years. The sites for extrapulmonary tuberculosis were peritoneum (35.3%, 6/17), cervical lymph node (17.6%. 3/17), bone marrow (5.9%, 1/17), spine (5.9%, 1/17), knee (5.9%, 1/17), brain (5.9%, 1/17), pericardium (5.9%, 1/17), cutaneous tissue (5.9%, 1/17) and genitourinary system (5.9%, 1/17). Fourteen of 15 tissue-biopsy specimens from suspicious sites revealed granulomatous inflammation. There were low yield in mycobacteria culture (11.1%, 1/9) and PCR (33.3%, 2/6). Three patients died during the treatment of the disease.

CONCLUSION

Extrapulmonary tuberculosis constitutes a major part of tuberculosis in dialysis patients. Tissue biopsy with invasive procedures, such as laparoscopy or laparotomy, may be necessary if clinical presentations are suspicious.

Extrapulmonary tuberculosis in a hemodialysis patient with unusual clinical presentation

The incidence of active tuberculosis in patients undergoing maintenance dialysis for a long time is considerably higher than that in general population. A 39-year-old male treated by hemodialysis three times a week for six months was admitted to the hospital with a painless mass palpable under his right areola. X-ray examination of chest showed a hyperintense lesion. Computed tomography revealed a cystic mass in the superior segment of inferior lobe near the thoracic vertebrae. Needle aspiration of the lesion revealed granulomas and acid-resistant bacteria. Anti-tuberculous therapy was therefore initiated. After eight months the patient was admitted back with paraplegia. Magnetic resonance imaging (MRI) revealed that the lesion defined by computed tomography (CT) was extending to the spinal duct and compressing the spinal cord. A tissue biopsy was performed and granulomas were identified. Mycobacterium tuberculosis grew in the culture. This case suggests that in areas with a high incidence of tuberculosis renal patients in a high-risk group should be examined periodically to exclude insidious infection and reduce morbidity and mortality.

Active tuberculosis in patients undergoing hemodialysis for end-stage renal disease: a 9-year retrospective analysis in a single center

OBJECTIVE

Tuberculosis (TB) in patients undergoing hemodialysis (HD) for end-stage renal disease (ESRD) is commonly thought to be associated with a very poor prognosis. Moreover, it is difficult to diagnose. This report was designed to describe this condition and to determine the mortality rate and risk factors associated with mortality. In addition, the study evaluated the usefulness of QuantiFERON TB-2G((R)) (QFT-2G).

METHODS

Retrospective study

PATIENTS

Patients with confirmed TB admitted between January 2001 and May 2009 were retrospectively identified and enrolled. The clinical, radiological, and bacteriological data at the time of admission were recorded. A multivariate analysis was performed to identify the predictive factors for mortality.

RESULTS

A total 19 TB patients (6 females; median age, 73 years) were included. TB occurred in most cases within 1.3 years from the initiation of dialysis. Most patients presented with fever (84.2%) and extrapulmonary TB (57.9%). The mortality rate within 24 weeks of the initiation of TB treatment was 36.8%. The factors associated with mortality were: a short duration of dialysis (HR 8.86, 95% CI 1.03-75.7, p=0.04), and underweight (HR 10.88, 95% CI 1.28-92.6, p=0.02). The sensitivity of QFT-2G, acid-fast smear, and polymerase chain reaction was 50, 80, and 88.2% respectively.

CONCLUSION

These data indicate a high incidence of TB in the early stages of HD and a high mortality rate among these patients. The clinical utility of QFT-2G was found to be limited. Hypoalbuminemia might therefore be related to either indeterminate or negative results of QFT-2G.

Tuberculosis in patients with end-stage renal disease undergoing dialysis in an endemic region of Turkey

The incidence of tuberculosis (TB) is high in end-stage renal disease (ESRD) patients undergoing dialysis. Diagnosis is difficult and delayed in this patient group owing to extrapulmonary involvement and nonspecific symptoms. Adverse effects of antituberculosis treatment are seen more frequently in these patients. We retrospectively evaluated the frequency and clinical progression of TB in 18 of 343 dialysis patients diagnosed with TB over a 5-year period at a university hospital in Adana, Turkey. Mean time between initiation of dialysis to diagnosis of TB was 19.5 +/- 26.1 months. Extrapulmonary TB was more frequent (77.8%) than pulmonary TB (22.2%). Diagnosis of TB was made based on clinical data in 1 patient, and microbiologically or pathologically in others. Antituberculosis treatment with 3 or 4 drugs was administered to patients for 6 to 12 months; second-line treatment was initiated in 1 patient infected with multidrug-resistant bacilli. One patient died owing to a cause other than TB; another was lost to follow-up. Adverse effects were hepatotoxicity in 3, optic neuritis in 1, and neuropsychiatric in 3 patients. A clinical response to therapy was achieved in all of the 16 patients who completed treatment. In conclusion, the incidence of TB and the frequency of extrapulmonary involvement are high in dialysis patients. Physicians must be alert to unusual presentations and localizations of the disease; TB must be strongly suspected in endemic regions. Owing to the greater frequency of adverse effects of treatment in these patients, they must be carefully observed during treatment.

Disturbances of acquired immunity in hemodialysis patients

Acquired immunity disturbances in hemodialysis (HD) patients are many and diverse. They are caused by uremia per se, the HD procedure, chronic renal failure complications, and therapeutic interventions for their treatment. Current data suggest that acquired immunity disturbances in HD patients concern mainly the T-lymphocyte and the antigen-presenting cell (APC). The T-lymphocyte-dependent immune response is deficient, predisposing to infections and inadequate response to vaccinations. In addition, APCs are preactivated, which seems to be responsible for the malnutrition-inflammation-atherosclerosis syndrome, and also affects T-lymphocyte function. At the molecular level it is assumed that the interaction between the APC and the T-lymphocyte is impaired. This disturbance is likely to concern the signal that results from the interaction between the major histocompatibility complex:peptide complex on APC surfaces and T-cell receptors on T-lymphocyte surfaces, or the signal that results from the interaction among the co-receptors of these two cells. The aim of the present review was to collect and classify the available clinical and experimental data in this area. Although many pieces are still missing from the puzzle, a better understanding of the responsible molecular mechanisms, will potentially lead to increased survival and a better quality of life in HD patients.

Detecting Latent Tuberculosis Infection in Hemodialysis Patients: A Head-to-Head Comparison of the T-SPOT.TB Test, Tuberculin Skin Test, and an Expert Physician Panel

Current guidelines advocate screening hemodialysis patients for latent tuberculosis infection; however, the tuberculin skin test (TST) is believed to be insensitive in this population. This study compared the diagnostic utility of the TST with that of an IFN-gamma assay (T-SPOT.TB) and the clinical consensus of an expert physician panel. A total of 203 patients with ESRD were evaluated for latent tuberculosis infection with the TST, T-SPOT.TB test, and an expert physician panel. Test results were compared with respect to their association with established tuberculosis risk factors. Tuberculosis infection, as estimated by the tuberculin test, T-SPOT.TB test, and expert physician panel, was detected in 12.8%, 35.5, and 26.1 of patients respectively. Among patients with a history of active tuberculosis and radiographic markers of previous infection, 78.6 and 72.7% had positive T.SPOT.TB results, compared with 21.4 and 18.2% who had positive tuberculin tests. The physician panel unanimously declared infection in these two groups. On multivariate analysis, a positive T-SPOT.TB test was associated with a history of active tuberculosis, radiographic markers of previous infection, and birth in an endemic country, whereas a physician panel diagnosis also was associated with a history of previous tuberculosis contact. The TST is insensitive in hemodialysis patients and is not recommended to be used in isolation to diagnose latent tuberculosis infection. It is suggested that a combination of T-SPOT.TB testing and medical assessment may be the most accurate screening method.

Mycobacterium tuberculosis infection following renal transplantation in Taiwan

BACKGROUND

Tuberculosis (TB) is one of the major causes of morbidity and mortality worldwide. Post-transplant (post-Tx) TB is a problem in successful long-term outcome of renal transplantation recipients. It is a life-threatening opportunistic infection that is frequently encountered, but the diagnosis is often delayed. With the emergence of newer potent immunosuppressive regimens and an increased incidence of TB in the general population, post-Tx TB among transplant recipients can be anticipated. Our objective was to describe the pattern and risk factors of TB infection, and the prognosis in an endemic area.

METHODS

This study was a retrospective review of the records of 756 renal transplant recipients in our hospital during the period from January 1983 to December 2003. The demographic data, transplant characteristics, clinical manifestations, diagnostic criteria, treatment protocol, and long-term outcome of this cohort of patients were analyzed.

RESULTS

Thirty-one episodes developed into TB in 29 patients (3.8%) with a mean age of 45.5 (range: 24.2-66.2) years and a mean post-Tx period of 57.9 (range: 1.2-145.2) months. The forms of the diseases were pulmonary in 22/31 (71%), disseminated in 1/31 (3%), miliary in 1/31 (3%), and extrapulmonary in 7/31 (23%). All patients initially received 4-drug combination therapy, and then dosage was adjusted based on clinical condition. Because of drug interaction, a mean 2-fold increase in the dose of calcineurium inhibitor, but no change in steroid, was required. Twenty-two patients (71%) had an elevated creatinine (Cr) level, and 6 (19%) patients did not recover owing to tissue-proof acute rejection (3 cases) and chronic allograft nephropathy (3 cases), respectively, after treatment. The serum Cr level on diagnosis of TB was 1.9+/-0.7 mg/dL; it then deteriorated to 2.4+/-1.5 mg/dL (P=0.134). Hepatotoxicity developed in 11 patients (35.5%) during treatment. Twenty-five patients were successfully treated, 2 patients remain under treatment, and 4 (12.9%) died. Based on univariate analysis, we found the post-Tx TB risk factors were diabetes and more than 3 episodes of rejection, modalities for acute rejection (high-dose steroid and anti-lymphocyte globulin), and maintenance therapy with steroid.

CONCLUSION

Post-Tx TB is a serious problem worldwide, and a high index of suspicion is warranted to ensure early diagnosis and prompt initiation of treatment for TB among renal transplant patients. The use of optimal immunosuppressive agents to minimize acute rejection seems reasonable to prevent TB infection in endemic areas like Taiwan. More than 9 months of treatment may be necessary to prevent recurrence.