Studies of the Variations in the Antistreptolysin Titer of the Blood Serum from Patients with Hemorrhagic Nephritis. I. Control Observations on Healthy Individuals and Patients Suffering from Diseases Other than Streptococcal Infections.

During some studies which have been in progress for several years upon the etiology and the clinical course of acute glomerular nephritis, it was considered desirable to examine the serum from these patients for antibodies to hemolytic streptococci. Comment has frequently been made to the effect that infections by this organism involving the upper respiratory tract usually precede the onset of acute hemorrhagic nephritis, and particular attention has been drawn to this matter in previous publications (1). Efforts to demonstrate the presence of specific agglutinins and specific precipitins for hemolytic streptococci in the serum from cases of acute, subacute and chronic glomerular nephritis were met with indifferent success and very irregular results, and the investigations were being abandoned when Todd published his observations on antistreptolysin. Todd (2) showed that the hemolysin produced by hemolytic streptococci, grown in a special medium free of animal sera, was antigenic and gave rise in rabbits to an antistreptolysin of considerable potency. Streptolysin formed by the growth of hemolytic streptococci in serum broth did not excite antibodies capable of neutralizing serum broth streptolysin nor would antistreptolysin of high titer neutralize serum broth streptolysin. Since it seemed probable that antistreptolysin might be formed in the serum of animals immunized to hemolytic streptococci, Todd tested scarlatinal antitoxin, erysipelas antitoxin and puerperal septicemia antitoxin, and found that antistreptolysin was present in high titer. Whereas the minimal neutralizing dose of normal horse serum was 0.2 cc. to 0.04 cc., the minimal neutralizing dose of the specific antitoxins was from 0.005 to 0.0002 cc. He further observed that the titers of diphtheria antitoxin, tetanus antitoxin, staphylococcus antitoxin, Small's non-hemolytic streptococcal antitoxin, antipneumococcal serum, antimeningococcal serum, and anti-gas gangrene serum did not differ from those of normal horse serum. Todd (3) then studied the reaction of the blood serum of man during infections by hemolytic streptococci. He recorded the antistreptolysin values of serum in units which are calculated as the reciprocal of the fractions of the cubic centimeters of serum employed. Under these conditions 0.01 cc. of serum equals 100 units, 0.03 cc. is equivalent