An evaluation of factors influencing the discriminative effectiveness of a group of liver function tests. II. Normal limits of eleven representative hepatic tests.

Summary Eleven representative liver function tests were performed on 720 healthy gainfully employed males. Frequency distributions were plotted for each test and the limits of normal determined. The 10, 5, and 1 per cent points of each distribution were listed for reference purposes. A transition zone of doubtful abnormality was defined on the left by scores falling at or between the 10 per cent and 5 per cent points of the distributions, and on the right by scores falling at the 1 per cent points of the distributions. Beyond the 1 per cent point is the zone of definite abnormality. It was proposed to consider a score in the transition zone abnormal if there were other evidences of abnormality and normal if there were not. The mean normal 1-minute serum bilirubin concentration was 0.11 ± 0.05 mg. per cent; the transition zone was 0.20 to 0.25 mg. per cent. The mean normal total serum bilirubin concentration was 0.62 ± 0.25 mg. per cent, and the transition zone was 1.0 to 1.5 mg. per cent. The thymol turbidity test had a mean value of 3.1 ± 1.5 units, and its transition zone was 5.0 to 8.0 units. The zinc sulfate turbidity had a mean value of 8.2 ± 2.4 units and a transition zone of 12.0 to 15.0 units. The mean percentage of cholesterol esters was 75.1 ± 2.0 per cent. Lower and upper limits of normal were calculated. The lower transition zone was 72 to 70 per cent, the upper 78 to 80 per cent. A curvilinear relationship was noted between Bromsulfalein retention and body weight. The correlation ratio was 0.49. An adjustment for weight was computed which affected specific weight groups, but did not appreciably alter the limits of normal for the group as a whole. With no adjustment for weight the mean value was 4.7 ± 2.7 per cent, and the transition zone was 8 to 14 per cent. After adjustment for weight the mean Bromsulfalein value was 4.2 ± 2.7 per cent, and the transition zone was 7 to 13 per cent. The average amount of hippuric acid excreted in one hour was 1.17 ± 0.21 gm. The zone of doubtful abnormality was 0.90 to 0.60 gm. A zone of probable hyperexcretion was also set at 1.40 to 1.60 gm. The mean value for the galactose tolerance test was 15.9 ± 8.8 mg. per cent at one hour. The transition zone was 30 to 42 mg. per cent. A mean value of 1.4 ± 1.1 mg. per day was obtained with the urine urobilinogen test. Its transition zone was 3.0 to 5.5 mg. per day. Urine coproporphyrin excretion was influenced by alcohol consumption. The average coproporphyrin excretion varied from 166 δg. per day for those who never drank, to 232 δg. per day for those who consumed large amounts of alcoholic beverages. For the particular group of males studied the transition zone in the downward direction was 110 to 80 δg. per day, and in the upward direction, 275 to 360 δg. per day. A combination of tests, called the cirrhosis abnormality score, was calculated for each subject. The mean value was -10.6 ± 4.0 units, and the transition zone of doubtful abnormality was -5.0 to + 1.0 units. Percentage incidence of "0" and ("1" ratings at 24 and 48 hours were calculated for the cephalin-cholesterol flocculation and colloidal red tests.