concanavalin-a and Giant-Cell-Arteritis

We studied an alpha-1-acid glycoprotein (AGP) and an alpha-1-antichymotrypsin (ACHT) microheterogeneity in sera of patients with polymyalgia rheumatica (PMR), giant cell arteritis (GCA/PMR), polymyositis/dermatomyositis (PM/DM) and healthy individuals by affinity electrophoresis with concanavalin A (Con-A) as the ligand. Our results are expressed as reactivity coefficients. The mean of AGP reactivity coefficients (AG-RC +/- SD) in PMR (0.92 +/- 0.17) and GCA/PMR (0.91 +/- 0.12) were significantly lower compared with the mean AG-RC in patients with PM/DM (1.48 +/- 0.52) as well as in healthy individuals (1.34 +/- 0.9). Moreover, an additional microheterogeneous form of AGP was noted in patients with PM/DM. In parallel, we also found that the mean of ACHT reactivity coefficients (AC-RC +/- SD) were lower in patients with PMR (2.94 +/- 1.24) and GCA/PMR (1.66 +/- 0.16) compared with healthy individuals (3.92 +/- 1.17). The mean of AC-RC in patients with PM/DM (6.74 +/- 4.35) was significantly higher than in patients with PMR and GCA/PMR as well as in healthy individuals. Our results show that the changes in reactivity of AGP and ACHT with Con-A are useful diagnostic markers for the differentiation of PMR and GCA/PMR from PM/DM.

Topics: Acute-Phase Proteins; Adolescent; Adult; Aged; Aged, 80 and over; alpha 1-Antichymotrypsin; C-Reactive Protein; Child; Child, Preschool; Concanavalin A; Dermatomyositis; Diagnosis, Differential; Electrophoresis; Female; Giant Cell Arteritis; Humans; Male; Middle Aged; Myositis; Orosomucoid; Polymyalgia Rheumatica

1. Using crossed immunoaffinity electrophoresis with free concanavalin A in the first dimension, we studied the glycan microheterogeneity of alpha 1-antichymotrypsin in sera from patients with giant-cell arteritis and/or polymyalgia rheumatica, and its variation in the serum of several of these patients during induction of disease remission by prednisone therapy and possible further recurrence of giant-cell arteritis and/or polymyalgia rheumatica. 2. In the serum of patients with active disease we observed increased proportions of concanavalin A nonreactive and concanavalin A weakly reactive fractions. The results were expressed as the ratio of concanavalin A non-reactive fraction plus concanavalin A weakly reactive fraction to concanavalin A reactive fraction, called R alpha 1-ACT. An R alpha 1-ACT higher than 1.8 (upper normal value) was found in 30/31 sera from patients with active disease (sensitivity 97%) and in 2/22 sera from patients with inactive disease (specificity 91%). 3. The erythrocyte sedimentation rate and the serum C-reactive protein level, common markers of biological inflammation, are usually elevated in active giant-cell arteritis and/or polymyalgia rheumatica. The two parameters are commonly used to guide the therapy during the course of the disease, but they have no specificity. An erythrocyte sedimentation rate of greater than 30 mm/h was found in 30/31 sera from patients with active disease (sensitivity 97%) and in 5/22 sera from patients with inactive disease (specificity 77%).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Aged, 80 and over; alpha 1-Antichymotrypsin; Biomarkers; Blood Sedimentation; C-Reactive Protein; Concanavalin A; Female; Giant Cell Arteritis; Humans; Male; Middle Aged; Polymyalgia Rheumatica