[Analysis of the acid glycoprotein heterogeneity in patients with arthritis]

The concentration measurement of the acute phase proteins in blood serum has been applied in differential diagnosis of inflammatory arthritis since a long time. However, it appeared that the qualitative changes such as the presence of different glycoforms of the acute phase protein that was a glycoprotein, enabled to differentiate acute inflammatory conditions including the chronic ones, and to determine the dynamics of inflammatory process. This phenomenon is defined as a main heterogeneity, whereas the determination of the proportions of particular glycoforms is known as glycosylation profile. The changes of this profile are well known in the course of acute inflammatory conditions such as: bacterial sepsis, skin burns complicated with bacterial infections or acute pancreatitis. Considerably less observations concern the chronic conditions as: rheumatoid arthritis, systemic lupus erythematosus and degenerative joint disease. The examination encompassed 25 patients with rheumatoid arthritis, 21 with systemic lupus erythematosus, 19 with reactive arthritis and 21 patients with degenerative joint disease whose diagnosis was established on the basis of international diagnostic criteria. In all these patient the changes of C-reactive protein (CRP), acid glycoprotein (AGP) as well as glycosylation profile of the AGP were evaluated. For this purpose the electrophoresis method of two affinity directions with concanavalin A was applied, whereas the concentration of particular acute phase protein was determined by Laurell's immunoelectrophoresis method. The variants of glycoprotein resulted from electrophoresis were calculated with aid of planimetric method, and the results were presented as a coefficient of glycosylation. The characteristic patterns of glycosylation profile in the course of systemic lupus erythematosus, rheumatoid arthritis and reactive arthritis may be useful in differential diagnosis of the above mentioned diseases.