Cutaneous Anergy in Patients Receiving Long Term Hemodialysis

Hemodialysis patients are at risk of acquiring tuberculosis, which is most often due to reactivation of the infection. As a result, screening for tuberculosis is recommended in hemodialysis patients. In this study, the rate of response to cutaneous PPD along with tetanus and diphteria toxoid antigens have been evaluated to define in hemodialysis patients. This clinical trial was conducted on 67 chronic hemodialysis patients in Labbafi Nejad Hospital during March- May 2001. PPD, tetanus and diphtheria toxoid solutions, with 1/10 dilution were administered by Manteaux technique and the induration was evaluated 48-72 hours, 7 and 9 days after. Of 64 patients, 18.8% had positive PPD tests and 26.6% had negative anergy tests through the first evaluation. The degree of constancy in the results of PPD and anergy tests during the three-time evaluation period were 23.4% and 18.7%, respectively, and the degree of induration was increased or decreased among the rest. Hemodialysis patients are at the increased risk for acquiring tuberculosis. Thus, negative cutaneous PPD results should certainly be revised and evaluated using anergy tests and repetitive readings of the test results. Attention must be paid to the “Delayed Type Hypersensitivity” (DTH) phenomenon presenting for the first time in the analysis of cutaneous test results. Finally, it is recommended to reconsider the value of cutaneous PPD test and its method of analysis in hemodialysis patients. (Tanaffos 2002; 1(2): 21-26)