Temporary Agglutinability of Red Blood Cells

As a result of studies on atypical isoagglutination it was concluded that the atypical feature is an unusual isoagglutinin acting at room temperature (20°-25°) on cells of the same blood group, or on cells of group O. These atypical agglutinins which occur in about 3% of normal individuals, possess a distinct specificity, the great majority describing the subgroups A 1 and A 2 , or the agglutinable substance known as P. Landsteiner and Levine 1 emphasized that the atypical property is a peculiarity, not of the blood cell, which could be readily grouped, but of the agglutinin in the serum. Consequently these atypical reactions do not interfere with the scheme of the 4 blood groups. In the blood to be reported, however, the results indicate that in this instance (a patient of group O) the exceptional property is the agglutinability of the cell which could be demonstrated by its sensitivity to an agglutinin present in about 15% of the sera, irrespective of the blood group. This peculiar property of the cell could be demonstrated during the illness of the patient, but not after recovery. From this it was concluded that the agglutinable property was induced by the specific nature of the illness (soluble products of pneumococcus type I) or by the therapeutic substances employed. Patient A. F., age 4, developed measles on March 17, 1938, and on the following day was admitted to the Willard Parker Hospital of New York City. The patient also showed signs of otitis media, bronchopneumonia, and later also fluid in the right pleural cavity from which pneumococcus type I was cultured. The same organism was also recovered from a pharyngeal swab and from blood cultures.