The role of tonicity in human isohemagglutination

Abstract

As was shown by Landsteiner and others, human bloods fall into three rather definite groups as regards isohemagglutination. The serum of members of group I agglutinate the corpuscles of groups II and III, but the corpuscles of group I are not agglutinated by any foreign human serum; members of group II agglutinate group III and are agglutinated by them; serum of members of group III agglutinate corpuscles of group II. Individuals in groups II and III, respectively, do not interagglutinate. It was found that constant relative differences in tonicity were present between these isoagglutinating groups, as was determined by the varying resistance, to hypotonic salt solutions, by the corpuscles of members of the respective groups, and by testing the tonicity of the various corresponding sera. Thus the tonicity of bloods of group I is found uniformly higher than that of bloods of groups II and III; bloods belonging to group II are higher in tonicity than those of group III. Simple hypertonic solutions of CaCl₂, but more particularly solutions hypertonic both in respect to NaCl and CaCl₂, produce a cohesion of human blood after several hours, that suggests isohemagglutination.

It is evident that hypertonicity alone, as regards total molecular concentration of all the substances present in serum, cannot account entirely for human isohemagglutination; although group II sera would agglutinate group III corpuscles, group III sera could not agglutinate group II corpuscles, as is the case. Relative differences in concentration of one or several salts or colloids could account for all the phenomena, as a given blood might be of higher molecular concentration in respect, say, to CaCl₂, and yet in total concentration be inferior to another blood, which it agglutinates.

It may be shown that when a serum of group I agglutinates a member of group 11, and another of group 111, the agglutinating power is apparently specific for each, as may be proved not only by ordinary absorption methods, but also by working with an “agglutinin” bound to the cells and then split off by heat to 50° C. (Landsteiner).