Gamma-glutamyl transpeptidase in synovial fluid, serum, and urine of patients with rheumatoid arthritis

The changes in the levels of GGT activity in various body fluids, ESR, SF-protein concentration, and SF-WBC count were determined in 59 RA patients and 18 control subjects. The SF-GGT and UGGT were markedly elevated in all RA patients investigated. The increase of SF-GGT is more pronounced than UGGT. The observation of comparable levels of SGGT in RA patients and control subjects indicates that SGGT does not gain entry into synovial fluid or urine. No differences were noticed in SF-protein concentration whereas ESR levels and SF-WBC counts were significantly higher in RA patients than in control subjects. Statistically significant correlations were observed between SF-GGT versus UGGT, SF-WBC, and ESR in females, and between SF-GGT and SF-protein and SGGT in male RA patients. The correlation coefficient values between UGGT versus SF-protein, SF-WBC, and ESR were found to be significant in male RA patients. UGGT levels correlated strongly with SGGT in all RA patients. These findings suggest that the measurement of SF-GGT and UGGT might be useful in understanding the pathogenesis of rheumatoid arthritis.     

Studies on urinary gamma-glutamyl transpeptidase in nephrotic syndrome patients

(1) Variations in the levels of GGT were measured in urine specimens taken in the early morning in control and in 20 consecutive adult patients with uncomplicated nephrotic syndrome. (2) The urinary GGT activity was increased in all cases of nephrotic syndrome patients investigated with different etiology. (3) A significant correlation was found between urinary GGT activity and serum albumin (r = 0.727) but not with serum cholesterol (r = 0.129). (4) These findings suggest that enhanced excretion of urinary GGT may be stimulated by decreased albumin concentration or oncotic pressure but does not appear to be due to leakage from plasma. (5) A systematic study on urinary GGT showed that GGT activity was decreased to the upper limit of normal control values in nephrotic syndrome patients after remission.