La Prueba De Inmunodiffusion En El Diagnostico De La Paracoccidioidomicosis

Abstract

The agar gel immunodiffusion technique was applied to the diagnosis of paracoccidioidomycosis. Sera from 21 cases of the disease were examined by this technique and by the complement fixation test, using filtrates obtained from the mycelial and yeast phases of Paracoccidioides brasiliensis. Immunodiffusion was positive in 16 cases and complement fixation in 15. Both tests gave negative results in 3 clinically cured patients and in 2 patients with active disease. The yeast filtrate produced precipitin bands in a larger number of cases than the mycelial one and also formed multiple bands more frequently. The technique gave negative results in: (a) 50 healthy individuals; (b) 21 patients with proved histoplasmosis, North-american blastomycosis, coccidioidomycosis and sporotrichosis; (c) 158 tuberculous patients and (d) 79 patients with pulmonary disorders of unknown etiology. Due to its simplicity, specifity and sensitivity the test has proved of value as a diagnostic tool. It can also be recommended as a screening test when a large number of sera must be processed.