SERUM ADENOSINE DEAMINASE ACTIVITY AND ITS ISOENZYME PATTERN AS A MARKER FOR MONITORING DISEASE ACTIVITY IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS

Total serum ADA activity (tADA) and the isoenzyme pattern of ADA were analyzed by the HPLC method using a specific inhibitor of ADA1, erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA). Systemic lupus erythematosus activity was assessed by SLE disease activity index (SLEDAI). Our data show that serum tADA activity was significantly increased in patients with active SLE compared to healthy controls. The isoenzyme analyses showed that the increased tADA activity in these patients was mainly due to increased ADA2 activity. In patients with active SLE, strong correlations were found between serum tADA and ADA2 activities. Moreover, serum tADA activity was strongly correlated to ESR and to anti-ds-DNA levels. Furthermore, serum ADA2 activity was strongly correlated to ESR.