The Middlebrook-Dubos Hemagglutination Test for Tuberculosis in Children and Adults1

Abstract

The occurrence of false positive and false negative Middlebrook-Dubos hemagglutina-tion reactions greatly limited the value of the test in the laboratory diagnosis of tuberculosis. The incidence of false positive reactions in non-tuberculous children was found to increase with age from 0% in newborn infants to 52% in children 5-14 years of age. The incidence of false negative reactions in patients with active tuberculosis decreased with age from 30% in children under 5 years of age to 5% in adults. The test failed to differentiate accurately between active and "healed" cases of tuberculosis. A Coombs modification of the test did not make the results more specific. Antibodies capable of agglutinating tuberculin sensitized sheep erythrocytes developed readily in guinea pigs injected with a saprophytic mycobacterium and less readily following injections of diphtheria toxoid.