CHEMOKINES CCL17 AND CCL22 IN SARCOIDOSIS

Abstract

Various immune cells as well as related cytokines are involved in immunopathogenesis of sarcoidosis and mechanisms of granuloma development. Currently, a role for chemokines in sarcoidosis has been extensively investigated, which is paralleled with a search for key molecules necessary for recruiting immune cells to intrusion site and granuloma formation as well as affecting outcome of the latter. Our study was aimed for determining level of plasma CCL17/TARC and CCL22/MDC chemokines in patients with sarcoidosis who received no immunosuppressive therapy is of high priority for clarifying some aspects in underlying immunopathogenesis as well as seeking out for secure clinical and laboratory criteria for assessing activity and disease prognosis. We studied peripheral blood plasma samples of the patients with sarcoidosis (n = 52). In 37% (19/52), they exhibited acute clinical manifestations, and 63% (33/52) had chronic sarcoidosis. The control group included peripheral blood samples from healthy volunteers (n = 22). The chemokine concentrations (pg/ml) were determined by multiplex analysis using xMAP technology (Luminex), and Milliplex MAP test system (Millipore, USA). In the patients with sarcoidosis, significantly higher levels of chemokines were shown relative to healthy volunteers: CCL17 – 78.24 pg/ml vs 26.24 pg/ml, p < 0.001; CCL22 – 660.60 pg/ml vs 405.00 pg/ml, p < 0.001. Evaluation of clinical and laboratory diagnostic characteristics for plasma chemokine levels in sarcoidosis patients allowed to assess their sensitivity and specificity. The respective values were as follows: in acute sarcoidosis: for CCL17 – 63% and 78%, CCL22 – 63% and 91%; in chronic sarcoidosis: CCL17 – 58% and 83%, CCL22 – 67% and 86%, respectively. In chronic sarcoidosis the levels of this chemokine correlated with the activity of angiotensin-converting enzyme (ACE), for CCL17 (r = 0.530; p = 0.003), for CCL22 (r = 0.446; p = 0.014). Patients with systemic lesions vs no systemic lesions (sarcoidosis of the respiratory system only) had significantly elevated CCL17 level: 102.82 pg/ml vs 32.72 pg/ml, p = 0.011. The concentration of chemokine CCL17 was significantly increased in patients with vs without signs of hepatomegaly: 130.73 pg/ml vs 51.60 pg/ml, p = 0.022. Levels of chemokines was significantly increased in patients with vs without ultrasound signs of splenomegaly comprising: for CCL17 – 249.18 pg/ml vs 46.87 pg/ml, p = 0.002; for CCL22 – 1271.40 pg/ml vs 660.63 pg/ml, p = 0.003. Thus, it should be noted that the peripheral blood plasma level of chemokines CCL17 and CCL22 may be used as additional prognostic markers in chronic sarcoidosis with varying scoring of clinical signs including with/without systemic disease manifestations.