Diagnosis of Tuberculosis in Dialysis Patients

Abstract

Patients with ESRD undergoing chronic dialysis are much more prone to develop tuberculosis (TB) than the general population. In these patients, the diagnosis of TB disease is often difficult because of prevailing extrapulmonary involvement and nonspecific symptoms. The prevalence of latent TB infection (LTBI) in ESRD patients is elevated, and those who become infected are at high risk of developing active disease. Therefore, screening for LTBI in this population is recommended, aiming to prevent progression to active TB and secondary contamination of others. The tuberculin skin test (TST), the classic diagnostic tool for LTBI, has several major drawbacks, including poor sensitivity (because of a high prevalence of anergy in dialysis patients) and specificity [with false-positive tests in those vaccinated with bacille Calmette-Guérin (BCG)]. In the past 10 years or so, new immunological tests using IFN-␥ release assays (IGRAs) have become available and have shown superior sensitivity and specificity for the diagnosis of TB compared with the TST in several studies, some very recent ones including ESRD patients. Therefore, current strategy in dialysis patients should use these tests instead of TST for LTBI screening and as an aid for the diagnosis of active TB.

Extrapulmonary tuberculosis presented as fever of unknown origin in two patients with endstage kidney disease not on dialysis: usefulness of 18-FDG-PET/CT in the diagnostic localization of fever of unknown origin

“…In this regard, positive results of IGRA do not confirm diagnosis of acute TB infection. Thus, the gold standard diagnosis is still the detection of Mycobacterium tuberculosis by culture or PCR using infected samples [8,15]. In the present case, both patients were negative for tuberculin skin tests, while IGRA was positive, suggesting that the attending physicians consider the possibility of active TB as the potential cause of the fever of unknown origin, although a positive result with IGRA does not confirm the presence of active TB.…”

“…A reason may be that the impairment of cellular immunity reaches its maximum at the time of dialysis initiation, because cellular immunity plays important roles as a defense system for organisms living in intracellular spaces, like TB [4,5]. In CKD, the cellular immune system is shown to be partly impaired by retention of uremic toxin, as evidenced by attenuation of tuberculin skin test [15,20]. Serum calcitriol, which is important for macrophage lineage cells in the prevention of TB reactivation, decreases in patients with CKD, especially in ESKD patients [21].…”

Genitourinary tuberculosis in children - a diagnostic challenge

“…This is a simple blood test that accurately detects people infected with Mycobacterium tuberculosis, used for the diagnosis of latent tuberculosis infection. QFT-GIT test uses tubes prefilled with antigens; this simplifies the laboratory procedures, making it more suitable for "on-field" usage in settings with limited resources (14,15).…”

A case of disseminated tuberculosis after the initiation of hemodialysis

“…A meta-analysis of the general population has suggested that interferon gamma release assays (IGRAs) should not be used to diagnose active TB, and that TB should only be diagnosed by microbiological approaches [17,18]. Segall et al [19], on the other hand, summarized the value of IGRAs for active TB infection in hemodialysis patients. The sensitivity and specificity of QuantiFERON-TB Gold (QFT-G) [20] and T-SPOT.TB tests [21] were both shown to be high.…”