The effect of methotrexate and azathioprine on the serum levels of IgA-alpha 1-antitrypsin complex in juvenile chronic arthritis.

In the present study we investigated the influence of methotrexate (MTX) and azathioprine (AZA) on the serum levels of the IgA-alpha 1-antitrypsin (IgA-AT) complex in patients with the systemic form of juvenile chronic arthritis (JCA). Fifty-six JCA patients (22 treated with MTX, 18 treated with AZA, and 16 not treated with any immunosuppressive agent) were enrolled in the study. MTX dosage ranged from 0.3 to 0.5 mg/kg-1 week-1, while AZA was given daily at an average dose of 1 mg/kg. MTX was given for 13 months (SD = 7 months) whereas AZA for 11 months (SD = 6 months). The average value of the complex was higher in JCA patients than in both control groups (0.74 +/- 0.73 U vs 0.37 +/- 0.13 U (control children), P < 0.001 and vs 0.23 +/- 0.12 U (control adults), P < 0.001). Values exceeding the normal range were found in twenty-two JCA patients (39.4%). Serum IgA-AT level was lowest in the MTX group compared to AZA and non-treated patients (0.56 +/- 0.24 U, 0.76 = 0.43 U, 0.95 +/- 0.52 U, respectively, P < 0.05). IgA values exceeding normal levels for age were found in 14% of the patients. A correlation between the levels of the IgA-AT complex and C-reactive protein (r = 0.43, P < 0.01), alpha 1-acid-glycoprotein (r = 0.45, P < 0.01), alpha 1-antichymotrypsin (r = 0.52, P < 0.01), alpha 1-antitrypsin (r = 0.40, P < 0.01) and IgA (r = 0.56, P < 0.01) was established.