In 103 (M = 25, F = 78) of 150 consecutive RA patients, values of the following variables were obtained at the start and end of a 2-year follow-up period: radiographic destruction score of hands and feet according to Larsen (Larsen index), Ritchie index, B-hemoglobin, ESR and plasma proteins (alpha 1-antitrypsin, ceruloplasmin, CRP, fibrinogen, haptoglobin, orosomucoid, IgA, IgG, IgM, C3 and C4). 60% of the values of delta LI (final minus initial value of Larsen index) were significantly larger than zero (11-44 units, p less than 0.05). delta LI was larger in females than in males (p = 0.11). Comparing women with duration of disease (DoD) 1-6 years versus 7-52 years. delta LI was larger in the former group (p = 0.005). Comparing women with the largest delta LI (19-44 units) with the remainder ones (delta LI = -9-18 units), CRP and haptoglobin was higher and IgM lower in the former group (p = 0.03, 0.02 and 0.03 respectively). In women with DoD 1-6 years (and only in this interval) significant linear relationships were found between delta LI and hemoglobin (r = 0.52, p less than 0.01) Ritchie index, haptoglobin, CRP (r = 0.41-0.46, p less than 0.05) and IgM (r = -0.43, p less than 0.05). The mean of repeated hemoglobin values correlated even more strongly with delta LI (r = 0.70, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)