Periostin Measerement
Serum periostin levels were assayed by ELISA method (Thermo Scientifc Multiskan GO, Finland) using commercially available periostin ELISA Kits (Elabscience catalog no: E-EL-H2452). The assay ranges for the periostin kit were 0.16-10 ng/ml, sensitivity 0.1 ng/mL and the intra- and interassay coefficients of variance (CV%) were 5.8% and 6.1%, respectively