| ABSTRACT. Immunocompromised patients such as those with end-stage kidney failure undergoing hemodialysis (HD) are at increased risk of developing tuberculosis (TB). For this reason,
routine TB screening of HD patients with tuberculin test has been recommended. The Center for
Disease Control and Prevention (CDC) has recommended that patients with chronic renal failure
should undergo annual skin testing for TB with tuberculin [purified protein derivative (PPD)],
with an induration of ≥10 mm at 48 h depicting a positive reaction. The aim of this study was to
compare the results of two different doses of PPD in dialysis patients. This descriptive and
comparative multicenter study was performed on 255 patients on chronic dialysis in Tabriz, Iran.
These patients did not have the PPD test done within the preceding one year. Patients were
divided into two groups randomly and conventional or double-dose tuberculin test was performed
using the Mantoux technique with 5 IU (group 1) and 10 IU (group 2) of PPD. Results were
interpreted 48–72 h after injection. Patients were divided into those with less than 10 mm and
those with ≥10 mm duration. Mean age was 44.6 ± 15 years (M/F = 1.5/1). The mean duration on
dialysis was 39 ± 7 months. There was no significant difference regarding the age, gender, duration on dialysis, causes of chronic kidney disease, erythrocyte sedimentation rate, C-reactive
protein and serum albumin between the two groups. The mean induration was 4.6 mm and 7.7
mm in groups 1 and 2, respectively. There was induration ≥10 mm in 19.6% and 25.5% of group
1 and 2, respectively, which showed a significant difference (P <0.05). In conclusion, because of
the high fre-quency of TB in dialysis patients, an annual tuberculin test may be recommended.
Our study showed that the double-dose tuberculin test may be a better substitute to the
conventional test in dialysis patients. |