Thymol and Dilution Turbidity Tests, their Relation to the Gamma‐Globulin Content of the Serum and the Morphology of the Liver Parenchyma

Abstract

The thymol turbidity test introduced by Maclagan (1) proved to be a very reliable indicator of the degree of morphological alteration of the liver parenchyma in generalized liver damage (Franklin et al., 1948), but as it depends on a disturbance of the serum proteins it is not a specific test for liver function. A positive thymol turbidity may be found in many diseases, notably in rheumatoid arthritis, lymphogranuloma venereum, heart disease, chronic pulmonary diseases, acute infectious diseases, malignancy, and in some other conditions in which no supporting evidence of liver dysfunction is apparent (Stillerman, 1948).A simple test providing similar information has been described by Dreyfuss (4), whose ,dilution turbidity test)) is based on the fact that in most sera turbidity develops after the addition of distilled water.The mechanism of the dilution turbidity test has as yet not been completely elucidated. It is possible that just as in the thymol turbidity test the turbidity depends on the presence of lipids and abnormal lipid protein complexes migrating in the /%globulin fraction during electrophoresis. Dreyfuss even suggests that the diluting effect of the distilled water contained in the thyniol reagent is mainly responsible for the production of thymol turbidity.I n this investigation both the thymol and the dilution turbidity tests have been performed in 388 sera in order to determine whether the tests give comparable results and whether discrepancies between them have any diagnostic significance.We also attempted t o determine whether there is a relationship between the results of the turbidity tests of the thymol group (i. e. thymol turbidity test and dilution turbidity test) and increases in the y-globulin fraction of sera. The results of the dilution and thymol turbidity tests have also been compared with the results of the Grostitration (5) carried out according to Verschure's modification (6)) the ~~ ~ Nebo-Hospital, 106 Schev. w , The Hague, Holland.178 C. K . V. VAN DOMMELEN A X D C. FRANCKE.latter test being an index for the albuminiy-globulin ratio of the serum (Verschure, 1948). I n 66 cases the histology of the liver (biopsy or autopsy specimens) was compared with the results of the dilution turbidity and thymol turbidity tests. Material and Methods.Tests were carried out on 369 sera from 316 patients suffering from various diseases and on 19 sera from normal subjects. The thymol turbidity test was performed according to Shank and Hoagland's modification (7) of Maclagan's method, but 0.15 ml of serum was added to 9 mI of the thymol reagent. By this method readings could be taken with the ))Lumetron 400 A)) photoelectric colorimeter (650 mp). The dilution turbidity test was carried out according to Dreyfuss (4): 0.6 ml of serum was diluted in 9 ml of distilled water. After 30 minutes readings were taken with the aid of the ))Lumetron 400 A)) (650 mp), using distilled water as a blank. I n jaundiced sera a blank consisting of 0.6 ml of serum in 9.0 ml of saline is preferable. The optical dens...