THE ROLE OF SERUM ANTI-TRYPSIN IN THE 

 ABDERHALDEN TEST* 



J. BRONFENBRENNER, W. J. MITCHELL, Jr., and PAUL TITUS 



(Pathological and Research Laboratories of the Western Pennsylvania Hospital, 



Pittsburgh, Pa.) 



In previous Communications (i, 2) we outlined the mechanism 

 of the Abderhalden test as an aütodigestion of serum protein of the 

 patient due to the removal of antitryptic inhibition. This removal 

 of anti-trypsin, although quite apparent in our experiments, has not 

 thus far been demonstrated directly. In this preliminary report we 

 wish to record the fact that actual measurement of the anti-trypsin in 

 the serum, before and during the progress of the Abderhalden reac- 

 tion, reveals the fact that the anti-tryptic titer of the serum is actu- 

 ally involved. The diminution of the anti-tryptic activity of the 

 serum, as tested against trypsin Solution, takes place in a specific 

 manner, inasmuch as it occurs only in cases where the serum used 

 is that of pregnant individuals and is parallel with the intensity of 

 the Abderhalden test; so that the estimation of anti-trypsin in serum 

 undergoing digestion, after its removal from contact with placenta, 

 may be used as a method of diagnosis of pregnancy parallel with, 

 and complementary to, that of the Abderhalden test. Moreover, it 

 is evident that this inactivation of anti-trypsin takes place at ice-box 

 temperature as well as at the temperature of the incubator. If the 

 Abderhalden test is divided into two periods, as was shown before 

 (3), over 30 percent of the anti-trypsin is removed during the first 

 part of the reaction, 



The comparison of the anti-tryptic index of the serum, before 



and during the Abderhalden test, with the index obtained by measur- 



ing the effect of kaolin and other substances capable of adsorbing 



anti-trypsin in a non-specific manner, confirms our contention (i) 



that the appearance of dialyzable cleavage products in serum may be 



determined by specific as well as by non-specific mechanisms, and 



that the esseritial part of this phenomenon is the removal of serum 



anti-trypsin, which in turn liberates the normal proteases of the 



serum, thus setting the serum into aütodigestion. 



* Proceedings of the Columbia University Biochemical Association, Dec. 4, 

 1914; BiocHEM. Bull., 1915, iv, p. 211. 



1 Bronfenbrenner : Proc. Soc. Exp. Biol. and Med., 1914, xü, pp. 4 and 7. 



2 Bronfenbrenner : Jour. Exp. Med., 1915, xxi, p. 221. 



3 Bronfenbrenner, Mitchell and Schlesinger : Biochem. Bull., 1914, iii, p. 386. 



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