[The level of serum thymic activity in patients with rheumatoid arthritis and systemic lupus erythematosus]. / Uroven' timicheskoi syvorotochnoi aktivnosti u bol'nykh revmatoidnym artritom i sistemnoi krasnoi volchankoi.

Thymic serum activity (TSA) has been studied in 52 healthy subjects, 48 rheumatoid arthritis patients and 17 sufferers with systemic lupus erythematosus aged from 18 to 70. TSA was compared in patients under and over 40 years. In those under 40 TSA appeared significantly inhibited, while in older subjects it did not differ from age-matched control. No correlations were reported between TSA levels and clinical characteristics. Changes in TSA levels may be related both to low content of thymic hormones and formation of inactive complexes from thymic mediators with inhibitors.