Enzyme immunoassay of urinary beta-hexosaminidase isoenzymes in patients with renal transplants.

beta-Hexosaminidase (NAG) and percent of NAG B were studied in twenty patients following renal transplantation. Median urinary NAG for twenty reference individuals was 0.26 U/mmol creatinine and NAG B was 24%. Urinary NAG decreased rapidly from a median of 3.7 U/mmol on the third day, to 1.2 U/mmol on the 15th day after transplantation in the patients with no major complications. The percentage of NAG B did not change significantly during this period and did not differ from the reference population. Rejection and cyclosporine toxicity were diagnosed on 17 occasions. Urinary NAG rose more than twofold in 15 of these episodes. The percentage of NAG B was slightly increased in 6 of these. Six months after discharge 17 of the renal transplants functioned well. They exhibited a marked decrease (almost normalized) of urinary NAG with no change in the percentage of NAG B.