IMMINOLOGICAL STUDIES IN PATIENTS RECOVERED FROM SARCOIDOSIS AND TUBERCULOSIS

tivity is the cardinal immunoiogic feature of sarcoidosis. It is also the main immunoiogic difference between active sarcoidosis and tuberculosis. In this study we have tested patients with sarcoidosis on recovery and inactive tuberculosis immunologically and compared their immune status with normal controls. Patients and Methods Immunological studies were performed on 75 patients including 25 with recovered sarcoi-dosis, 25 with inactive, treated tuberculosis and 25 control subjects. Alf patients were attending the Poole Chest Clinic, Poole, Dorset. Initial diagnosis of sarcoidosis was based on clinical and/or radio-logical evidence together with histological evidence of non-caseating sarcoid granuloma. At the time of study these patients were classi-fied as recovered as they appeared to have made complete clinical and radiological recovery. The diagnosis of tuberculosis was made on the basis of bacteriological evidence of tubercle bacillus. At the time of study all the 25 patients were bacteriologically inactive and were not receiving anti-tuberculosis therapy. The control subjects had no disorder which might produce an immunological upset or lead to impairment of hypersensitivity respon-ses. The induction of delayed-type hypersensiti-vity was tested by both intradermal tuberculin and by Candida antigen and also by dinitro-chlorobenzene (DNCB) sensitisation. Thus the three different tests were carried out and in all 75 subjects. Test 1: The Tuberculin test was evaluated by the intradermal inoculation of 1: 1000 old tuberculin in the forearm. The test site was read at two days for the presence of indura-tion exceeding 5 mm in diameter. Erythema without induration was not accepted as evidence of delayed-type hypersensitivity