Factors affecting TST level in patients undergoing dialysis: a multicenter study.

Area of Science:

• Nephrology
• Immunology
• Infectious Diseases

Background:

• Patients with chronic kidney disease (CKD) exhibit an elevated risk of tuberculosis (TB).
• Tuberculin skin test (TST) is a common method for assessing TB exposure and cellular immunity.
• Understanding TST response in CKD patients on dialysis is crucial for TB risk stratification.

Purpose of the Study:

• To evaluate TST response in patients with CKD undergoing dialysis.
• To identify factors influencing TST reactivity in this population.

Main Methods:

• A cohort of 371 CKD patients on dialysis were administered the purified protein derivative TST.
• Patient data including age, gender, smoking status, comorbidities, Bacille Calmette-Guerin (BCG) scar status, vitamin D treatment, and parathormone (PTH) levels were collected.
• Logistic regression analysis was employed to determine factors affecting TST response.

Main Results:

• The study included 371 patients (194 men, 177 women) with a mean age of 60.09 years.
• Elevated parathormone (PTH) levels and vitamin D treatment were significantly associated with TST negativity (P=0.002 and P=0.007, respectively).
• Hypertension was the most frequent comorbidity among the 61.7% of patients with co-existing conditions.

Conclusions:

• This study is the first to demonstrate a correlation between TST negativity and elevated PTH levels and vitamin D treatment in CKD patients.
• Findings suggest that high PTH levels may suppress the immune system, particularly cellular immunity, in CKD patients.
• Further research is warranted to elucidate the immunomodulatory effects of PTH in CKD and its impact on TB risk.