Summary
Background. Vasculitides associated with anti-neutrophil cytoplasmic antibod ies (ANCAs) are systemic auto immune diseases that affect small to medium- sized blood vessels. Although they are relatively rare, they must be diagnosed and treated early because the untreated disease may rapidly develop into multiple organ failure and death. Endothelin-1 (ET-1) is not only a potent endogenous vasoconstrictor, which mediates proliferation and fibrosis of vascular wall cells, but also is a proinflammatory protein, which leads to activation of macrophages and adhesion of neutrophils. ET-1 is not a marker used in a daily routine, but, according to scientific literature, it can be used to detemine endothelial damage.
The aim of the study was to assess the relationship between endothelin and ANCA by investigating ET-1 concentration and its connection with inflammatory markers in ANCA positive patients.
Methods. The study in cluded 29 ANCA pos i tive pa tients (79.3% women and 20.7% men). The average age of women was 54.30±15.45 years old, the average age of men was 66.17±14.13 years old. ANCA existence in the serum was determined by indirect immunofluo rescence whereas the serum levels of ET-1 (pg/mL) were determined by enzyme- linked immunosorbent as say (ELISA). The information about patients’ inflammatory markers (C-reactive protein (CRP), erythrocyte sedimentation rate, neutrophil number) was taken from the information system of the hospital. The statistical analysis was based on non-parametric methods because data did not meet the assumption of normality. The results were considered to be statistically significant if p<0.05.
Results. In all our patients, the levels of ET-1 were found higher than the upper limit of the recommended range (0.647 pg/mL). There were no significant differences found in ET-1 concentration neither between different ANCA types, gender, age groups nor groups of diseases. We found a moderate-strength statistically significant relationship between ET-1 and CRP concentrations (rs=0.59, p=0.005).
Conclusions. The results suggest that ET-1 is closely related to the pathogenesis of ANCA and neither age nor gender has a significant effect on this relationship. Increased ET-1 concentration may be found in several disease groups, and the severity of endothelial damage is independent of the ANCA serotype. In addition, the results suggest that CRP and ET-1 synthesis could also be related. This shows that both ET-1 and CRP may be used to monitor inflammation in ANCA positive patients.
