We found that the erythrocytes of the patients with pulmonary tuberculosis were agglutinated by the serum immune against tuberculosis. This hemagglutination reaction is concerned with the erythrocytes of tuberculous patients, and the Middlebrook-Dubos reaction with the serum of tuberculous patients.
The immune serum against tuberculosis was prepared from a rabbit which was inoculated with virulent human tubercle bacilli. Before the use of the immune serum its heterohemagglutinin was absorbed by the erythrocytes of healthy human beings of blood group AB. A multiple dilution of the absorbed serum was carried out by 0.15 mol phosphate buffer solution.
The suspension of the erythrocytes to be examined was dropped into each of the diluents mentioned above.
After a 3 hour incubation at 37°C and then about a 12 hour standing at 20°C, the hemagglutination was read through an agglutinoscope.
The hemagglutination titer was lowest in 27 cases of tuberculin-negative people who had never been vaccinated with BCG, and relatively low in 66 tuberculin-negative people having previously been vaccinated with BCG, and highest in 140 patients with pulmonary tuberculosis.
It was concluded as follows:
1) There is something having to do with the immunity against tuberculosis in the erythrocytes of patients with pulmonary tuberculosis.
2) If our hemagglutination reaction can be considered as an antigenantibody reaction concerning tuberculosis, it necessarily follows that both antigen and antibody of tuberculosis exist simultaneously in the blood of patients with pulmonary tuberculosis.