The Kveim test in leprosy.

From the older literature it has been claimed that a significant proportion of patients with the tuberculoid, but not the lepromatous, form of the disease, gave positive Kveim reactions. It is concluded, however, from a review of this older literature that none of the claims are based on studies using a validated Kveim antigen and that the majority of the readings were based on macroscopic, rather than microscopic assessment. The International Study by Siltzbach on Kveim tests in leprosy patients using a validated antigen and assessed microscopically reveal no positive reactions among fifty-seven patients with all types of leprosy from Finland, Israel, Italy and Turkey. However, this same study on Japanese patients gave two positive and five equivocal Kveim reactions among ten lepromatous patients and one equivocal reaction among three tuberculoid patients. Our own studies in Malaysia with the same validated Kveim antigen used by Siltzbach and assessed microscopically gave one weak positive Kveim reaction among twenty-one lepromatous patients and four equivocal Kveim reactions among nine tuberculoid patients. It is concluded from these results that, with the possible exception of Chinese and Japanese patients, false positive Kveim reactions are extremely rare in patients with all types of leprosy. Therefore in parts of the world where leprosy is endemic the Kveim reaction can still be accepted as an important confirmatory diagnostic test for sarcoidosis. It is suggested that further surveys of Kveim reactivity be undertaken on Chinese and Japanese leprosy patients, since both have a similar ethnic origin, in order to determine whether such patients are more liable to elicit a granulomatous reaction to Kveim antigen.