[Gamma-glutamyltranspeptidase in chronic polyarthritis. I. Comparison with a control group and relationship with alkaline phosphatase].

Gamma-GT, alcaline phosphatase and other parameters of abnormal liver functions were estimated in 54 consecutive in-patients having active RA but without a previous history or clinical signs of liver disease, and compared with a matched control group, suffering from degenerative rheumatic disease. There was a slight to moderate elevation of gamma-GT in 40.4% of the RA-patients (mean value 27.2 IU/l) and in 32.1% (mean value 22.3 IU/l) of the control group, respectively. The difference was not significant. Abnormal values in the control group occurred mainly in patients with peri-arthropathia of the shoulder, before mobilisation under anaethetic (3 of 5) and - coxarthrosis before total hip replacement (4 of 12). Alkaline phosphatase was elevated in 25.9% of the RA-patients (mean value 41.3 +/- 21.9 IU/l) and in 14.8% of the control group (mean value 34.3 +/- 15.9 IU/l). The difference was significant. There was a correlation between gamma-GT and alcaline phosphatase in the RA-group (r = 0.549, p less than 0.001) but not in the control group (r = 0.102). Abnormal values found in the control group were mainly found among patients with osteoporosis, following fractures, and coxarthrosis. The frequency of abnormal results and the value of the means increased with raising disease activity. Two groups of 30 and 32 patients, respectively, were examined at intervals of 2 or 4 weeks over a period of 6-10 and 18 months, respectively, and showed temporary elevations os gamma-GT in 3/4 of all patients, of GOT in 2/3 of alcaline phosphatase in 1/2 and of GPT in 1/3. Compared with other parameters of liver disease gamma-GT did not react in a different but in a more sensitive way. In our opinion it is the most sensitive indicator of reactive changes of the liver in RA.