The Major Leukocyte Protein L1 as an Indicator of Inflammatory Joint Disease

Abstract

L1 is a major protein in granulocytes and monocytes. It is released during activation of these cells, and the plasma level of L1 is therefore thought to reflect the turnover of leukocytes. Peripheral blood from % patients hospitalized in a rheumatological department, was analysed for L1, C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The total patient material was divided into groups depending on diagnosis: 47 patients with rheumatoid arthritis, 27 patients with arthritis of different etiologies, 15 patients with non-inflammatory diseases and 7 patients with arteritis. Correlation analysis were made between the different laboratory parameters. A high positive correlation was found between L1 and CRP in all the groups, and with a correlation coefficient of the total patient material of 0.68 (p < 0.001). The correlation coefficient between L1 and ESR was 0.54 (P < 0.001) in the total patient material, and between CRP and ESR it was 0.66 (p < 0.001). The results indicate that the L1 protein could be a new laboratory marker of inflammation in rheumatic diseases.