Thermal Coagulation Point and Iodoacetate Index as Detectors of Abnormal Serum Proteins and Underlying Illness

Comment and conclusions

The simultaneous determination of thermal coagulation of blood serum in a large series of cases by the measurement of thermal coagulation point and iodoacetate index has shown similarity of results. There was an inverse relationship, in most instances, between the level of the thermal coagulation point of serum and the concentration of iodoacetate necessary to prevent heat coagulation. The dissociation between the results of both technics appeared exclusively in the group of cases showing a moderate defect in thermal coagulation. This could have resulted, in part, from calculation of the thermal coagulation defect, in the case of the iodoacetate index, in terms of total proteins content, and the omission of the protein factor in the estimation of the thermal coagulation point of serum. It must have been due at times, however, to the results obtained with the iodoacetate technic, which, for unknown reasons, are not always reproducible( 7 , 9 ). The percentage of abnormalities found in the pathological sera with both technics, singly or combined, in cancer cases and non-neoplastic diseases, was very similar. Neither technic permits a sharp differentiation between neoplastic and nonneoplastic disease. Since abnormal thermal coagulation seems to be related to decrease in sulfhydryl groups of serum proteins which occurs in cancer( 18 ), as well as in metabolic and infectious diseases( 19 ), there is no theoretical basis for the use of measurement of defective thermal coagulation as a diagnostic test for cancer.

The calculation of the thermal coagulation defect per unit of serum proteins, as in the Huggins technic, has not added to the specificity of this method for differentiation of neoplastic from non-neoplastic diseases, nor changed the total percentage of serological abnormalities in pathological material tested. It is possible, however, that the employment of two or more technics for determination of abnormal structure of serum gel may increase the percentage of pathological sera detected. This occurred when the serum gel was tested simultaneously by the measurement of the thermal coagulation point, and the determination of the speed of diffusion of electrolyte through the gelified column of serum( 20 ).

Quantitative disturbances in serum proteins can be detected by many non-specific methods, including serological flocculation or turbidity reactions and sedimentation rate. Determination of qualitative alteration within individual fractions of serum proteins requires much more complicated technics( 21 - 24 , 2 , 6 ) or study of the electrophoretic pattern of serum. The chief advantage of the method of examination of thermal coagulation of serum is that it provides a very simple way to detect certain quantitative and qualitative alterations. which frequently escape other non-specific serological tests, which are dependent upon different abnormalities in proteins. Thus the presence of disease is easily discovered and diagnostic and prognostic conclusions may be drawn( 3 ). Measurement of the thermal coagulation of serum with determination of the thermal coagulation point is simpler than other technics. It has a smaller intrinsic error because it does not require an additional measurement of protein concentration, nor the calculating of a ratio. The results obtained by either method are equally significant for the detection of abnormal thermal coagulation; the scope of both is determined by factors inherent in the basic principle.