PIIINP and VEGF determination Plasma PIIINP levels will be determined using ELISA kit (USCN, China). PIIINP levels are expressed as ng/mL as a marker of tissue collagen deposition and fibrosis. Serum VEGF will be determined as a marker of neo-angiogenesis and tissue re-modeling using an ELISA kit (Bender MedSystems, Austria), data being expressed in ng/L.