Latent Tuberculosis Treatment Cascade in Chronic Kidney Disease Patients: The Vancouver Experience

Background: Diagnosis and preventative therapy (PT) in patients with latent tuberculosis infection (LTBI) remains a core strategy for tuberculosis (TB) elimination. Much of the current literature on LTBI in patients with end stage kidney disease (ESKD) has focused on the effectiveness of available screening tools. There is little data on PT in the ESKD population. The objective of this study is to examine treatment regimens, uptake, treatment outcomes, and adverse events of LTBI treatment in ESKD patients in Vancouver, British Columbia.

Methods:We conducted a retrospective chart review from 2007 to 2014 from the British Columbia Centre for Disease Control (BCCDC) TB registry. We included all patients identified with ESKD assessed in BCCDC TB clinics. ESKD was defined as any patient with eGFR <15/mL/min//1.73 m2, patients receiving dialysis, and renal transplant recipients. Patients were diagnosed with LTBI via clinical assessment, tuberculin skin test (TST), and/or interferon gamma release assay (IGRA).

Results: In total 618 ESKD patients were assessed at BCCDC clinics; 605 were prospective or current dialysis patients; and 13 were renal transplant recipients. LTBI was diagnosed in 132 patients: 112 patients tested IGRA positive, 17 were TST positive or were offered therapy based on clinical/radiological findings. Of the 132 patients diagnosed with LTBI, 97 (73.5%) initiated LTBI therapy, with 76 patients (78.4%) completing an LTBI treatment course. Of the patients that completed therapy, 59 (60.8%) completed a course of INH, 9 (9.3%) completed a course of RIF, 7 (7.2%) started a course of INH and switched to complete on RIF, and in 9 (9.3%) treatment was ongoing. Of the 10 patients who did not complete treatment 6 (60.0%) patients stopped early due to drug reactions. In total 30 (30.9%) patients had adverse reactions and 1 (1.0%) had a significant reaction requiring hospitalization. There were no deaths associated with treatment.

Conclusion: This case series demonstrates that despite having multiple comorbidities, high rates of adverse reactions, and complicated pharmacotherapies, a high proportion of CKD patients can complete an LTBI treatment course. Further study is required to understand the cost-effectiveness and epidemiological effects of LTBI screening and treatment in this population.