Background:Wound healing is a complex process requiring the collaborative efforts of different tissues and cell lineages, and involving the coordinated interplay of several phases of proliferation, migration, matrix synthesis and contraction. A keloid is an abnormal proliferation of scar tissue that forms at the site of cutaneous injury; it does not regress and grows beyond the original margins of the scar.Osteopontin (OPN) is a multifunctional matricellular protein produced by a broad range of body cells including T cells, macrophages and fibroblasts, and research has defined a role for osteopontin in maintenance and reconfiguration of tissue integrity during inflammatory processes. Moreover, OPN regulates fibroblast behavior and myofibroblast differentiation. Expression of OPN in normal, healthy skin is low but increased during wound healing.Based on previous studies osuggesting a role of OPN in fibrous tissue formation, we hypothesize that OPN may contribute to inflammation-associated fibrosis, and accordingly keloid formation in skin wounds.Aim of work:The aim of this study is to verify if serum and/or tissue osteopontin is an indicator of keloidal tendency in certain subjects, so as to help screen for an individual's tendency to develop keloids, take adequate prophylactic measures before and immediately after interventional procedures in susceptible individuals, and help guide future therapeutic modalities for keloids.Patients and methods:34 patients presenting with keloids were recruited, and followed a specified inclusion and exclusion criteria. 35 subjects not having keloidal tendency, not having any of the exclusion criteria, and age and sex matched with the investigated patients, were used as control population. Serum OPN was measured for all patients and controls, and for a subgroup of 5 patients, tissue OPN was measured in keloidal and non-keloidal skin as well as in normal skin of 5 controls. All samples were examined in one sitting for OPN level using ELISA technique.Results:Serum osteopontin level showed a highly significant statistical increase in patients with keloidal tendency when compared with normal controls. Additionally, highly significant increase of tissue OPN level in keloidal and non-keloidal skin of patients was found compared with that of normal skin of controls. Additionally, there is a highly significant increase of tissue OPN level in keloidal skin than in non-keloidal skin of same cases.Conclusion and recommendations:•OPN seems to a significant play a role in keloid formation. And we suggest that serum OPN can be used as a prognostic marker or a risk factor for fibrotic tendencies. •We recommend that patients with fibrotic tendencies should be treated post-trauma by anti-OPN therapy to prevent occurrence of keloid and we also recommend further studies regarding OPN gene polymorphism in patients with keloidal tendency and studies regarding possible increased risk of infection after administering anti-OPN therapy.