[Tuberculin skin test reactivity in patients with chronic renal failure]

The aim of this study was to evaluate the response of tuberculin skin test (TST) and the parameters that affect the response in patients with chronic renal failure (CRF) on different treatment regimens. The study population consisted of 150 patients (78 females, mean age 48.1 + or - 16.7 years, the mean disease duration 6.6 + or - 6.1 years). Of these patients, 50 were on haemodialysis (HD), 50 were renal transplant patients, 26 were on peritoneal dialysis (PD) and 24 were treated medically. TST was performed to all patients, an induration with a diameter of 10 mm or more was accepted as positive response in HD, PD, medical treatment groups, whereas 5 mm or more was considered as positive in transplant group. TST was positive in 52% of the study population (56% in HD group, 54% in PD group, 44% in transplant group, 58% in medical treatment group, p> 0.05). There was a positive correlation between TST and age in patients older than 60 of transplant and medical treatment groups (p= 0.008). In HD patients with negative TST, the number of female patients was higher (p= 0.02). In transplant patients with positive TST, duration of HD was shorter (p= 0.01), the blood urea level was lower (p= 0.04), hemoglobin level was higher (p= 0.04). The ratio of negative TST was higher (p< 0.05), TST reactivity was smaller (p= 0.01) in only transplant patients with no BCG scar. The number of BCG scar was correlated positively with TST (p= 0.04). In the medical treatment group, patients with positive TST response were older (p= 0.02) and in PD group the tuberculin reactivity was not affected by any of the patient-related parameters. It must be considered that the response to TST is low in young patients with uncontrolled CRF and under immunosuppressive therapy.