Heterophile Antibodies in Serum Sickness

Abstract

Summary The sera of 21 patients afflicted with horse serum sickness, whose blood was obtained during or at various intervals following the disease, were examined for agglutinins and hemolysins for sheep blood. Every one of them contained agglutinins for sheep blood, in titers varying from 1:4 to 1:64. Of 450 cases with no history of serum sickness, only 19 or 4.2 per cent showed agglutinins for sheep blood. All these 19 positive cases agglutinated only in the lowest dilution used (1:4). Four of the 21 cases showed a very remarkable increase of antisheep hemolysin, complete hemolysis occurring in dilutions: (1:192) (= 0.0026 cc.), (1:384) (= 0.0013 cc.), (1:768) (= 0.0006 cc.), (1:1536) (= 0.00032 cc.), while the highest titer found normally in a large series of control cases was 1:128 (= 0.004 cc.). Very fresh sheep erythrocytes were somewhat less agglutinable than older ones; their hemolysis was not influenced by age. Only one serum lost its antisheep agglutinins on standing. An immediate reaction in one patient (case 2) following injection of horse serum is brought in connection with the finding of agglutinins in a blood specimen obtained 20 hours following injection. The agglutinins were probably present before the injection of serum. In one of the serum sickness cases (no. 9) and one of the control cases (no. 13) the development of agglutinins following the injection of horse serum was observed by repeated titrations. Two cases (nos. 13 and 22) developed agglutinins following injection of horse serum, but no serum sickness. Three cases (nos. 10, 11 and 19) showed no agglutinins and no serum sickness following injection, while 6 cases found free from agglutinins before injection of serum did not develop serum sickness. A case of bovine serum sickness did not develop antisheep hemolysins. The heterophile nature of the agglutinins and hemolysins found in the serum of patients with horse serum sickness was established by absorption experiments.