Clinical correlationof potential markers of the systemic scleroderma activity

Overview

Systemic scleroderma (SSc) is a disease characterized by vascular damage, skin and internal organconnective tissue thickening or fibrosis. Variability of clinical symptoms, chronic course of thedisease and little value of acute-phase reactant measurement, all contribute to the lack of specificmarkers for the disease activity, which would help with indication of treatment and further followup of SSc. The aim of this study was to verify if some selected factors could serve as SSc activitymarkers. Clinical correlations of potential markers of disease activity, determined in a group of SScpatients at the start of the study and after 1 year were compared. In total 49 patients were examined– 36 with limited, 9 with diffuse and 4 with other forms of SSc. The circulating levels of N-terminalpropeptide of procollagen type III (PNPIIIP), interleukin-6 (IL-6), soluble interleukin-2 receptor(sIL2-R), intercellular adhesion molecule-1 (sICAM-1), vascular adhesion molecule (sVCAM-1), of vonWillebrands factor antigen (vWFAg), big endothelin-1 (BET-1), and urine excretion of pyridinoline(PYR)anddeoxypyridinoline (D-PYR)were determined.Then the correlations of these markers withclinical data reflecting activity and with functional questionnaire (FQ) were measured. The meanlevels ofsICAM-1,sVCAM-1,vWFAg,sIL-2R,BET-1 andPYRwerenot significantly elevatedcomparedwith normal levels. Concentration of NPIIIP, D-PYR and IL-6 were normal. No significant differencewas found in the levels of any of these markers at control measurement after 1 year. The level ofNPIIIP correlated with the finger to palm (FTP) distance as well as with D-PYR concentration andFQ. IL-6 levels correlated with leukocyte count, sIL-2R and FQ. The same correlations were foundfor NPIIIP and D-PYR after 1 year. IL-6 levels and FQ, even sIL-2Rand erythrocyte count correlated.BET-1 concentration and decreased DLCO correlated. Correlations of collagen turnover markerswith skin damage indicators and with FQ, conforming with literature data, support their possibleuse for monitoring of fibrotic changes. Correlation of endothelial markers damage with activationof the immune system will have to be verified in larger studies.

Key words:
systemic sclerosis, activity, collagen, adhesion molecules, interleukins, endothelin