Relationship between severity of rheumatoid arthritis and serum alpha 1-antitrypsin.

We determined serum alpha 1-antitrypsin phenotypes and levels in 281 patients with classical or definite rheumatoid arthritis (RA). The prevalence of the MZ phenotype in our patients with RA was not increased, as there were only 3 MZ cases (1.1% of all cases and 1.4% of seropositive cases) compared to the 3% prevalence in controls. The FM phenotype was detected in 6 cases, a prevalence rate of 2.1%, significantly higher than in controls (prevalence less than 0.4%). Increased serum levels of alpha 1-antitrypsin were independently associated (p less than 0.01) with the presence of wrist joint erosions and the use of gold and/or penicillamine for treatment; this association may represent a serum antitrypsin response to more severe disease.