The use of beta-N-acetylglucosaminidase excretion to investigate renal disease in rheumatoid arthritis.

Urine levels of the lysosomal enzyme beta-N-acetylglucosaminidase have been measured in patients with arthritic disorders; significantly higher levels were found in patients with rheumatoid arthritis (mean: 332.9 nmol/h/mg creat.) than in those with degenerative joint disease (mean: 86.31 nmol/h/mg creat.; P less than 0.001). Analysis of the results shows that salicylates were responsible for some of this difference, but suggests that rheumatoid disease itself may cause renal damage.