Interspecies reactivity and intraspecies specificity of antilymphoid globulin

It has been said that heterologous antilymphocyte serum is highly specific in that (a) it lyses or agglutinates equally well the white cells from all members of the species which provided the immunizing lymphoid tissue3 and (b) that it does not react with the white cells from other species.1, 3, 4, 6 The fore-going concepts were based upon studies employing anterisera of relatively low titer. These questions have been re-examined with antidog- and antihuman-lymphoid globulin of high titer raised in horses with repeated subcutaneous immunization with lymph node, thymus, and spleen tissue.5 It has been found that the white cells of individuals within the species population, against which the anti-bodies were directed, were variably affected by the immune globulin. Furthermore, it has been shown that there is not an absolute species specificity inasmuch as some reactivity against the white cells of at least seven widely divergent species is present in either antidog- or antihuman-lymphoid globulin.