[Cold agglutinin titers in the sera of patients apart from the atypical pneumonia cases-against the patients' own erythrocytes and the O group human erythrocytes].

The titers of cold agglutinins against the patients own erythrocytes and the O group human erythrocytes in 72 cases, who had not primary atypical pneumonia and other respiratory system infections, were studied. The aim was to confirm the characteristics of the relationship between the results of these two tests.