Background: Osteoarthritis (OA) is a multifactorial disease that commonly affects the knee. Tumor necrosis factor-α (TNF-α) is able to regulate inflammation in OA. Macrophage migration inhibitory factor (MIF) may be involved in the pathophysiology of arthritis. Platelet-rich plasma (PRP) may reduce pain associated with OA. The current study aimed to assess the possible therapeutic effects of PRP in patients with knee OA of various severities.~Methods: A prospective study was performed on 90 patients were included and categorized into mild (30 cases, moderate (30 cases) and severe (30 cases) knee OA. Three intra-articular (I.A) injections of PRP, 2 weeks a part, were received. Pain score and MRI Osteoarthritis Knee Score (MOAKS) were assessed. Serial synovial fluid cytokines assays in the form of Tumor necrosis factor-α (TNF-α) and Macrophage migration inhibitory factor (MIF), were performed using commercially available ELISA assay kits. The assays were performed pre-injection (S1), two weeks from the 1st I.A injection and two weeks from the 2nd I.A injection (S3) for all included patients.~PRP preparation: The PRP needed for IA injection has been prepared under complete aseptic conditions. In order to avoid the effect of food intake on purified PRP, on the day of injection the patients were instructed to fast for 4 hours before blood collection. Approximately 20 mL of venous blood were drawn from the antecubital vein using an aseptic technique in an effort to avoid irritation and trauma to the platelets. Anti-coagulated blood was obtained in ten extraction tubes (2 mL each), containing sodium citrate. The tubes were then centrifuged at 2100 rpm at room temperature for 8 minutes to separate the blood in each tube into the citrated plasma, the buffy coat and the residual red blood cells ( RBCs) . Using a pipette, the PRP situated just above the selectively precipitated RBCs but not including the buffy coat was carefully aspirated from each tube. In each affected joint, 10-mL PRP samples (from the collected venous blood) were used for IA injection . For each intra-articular injection new fresh PRP samples were made from the patients.
A prospective study was performed on 90 patients were included and categorized into mild (30 cases, moderate (30 cases) and severe (30 cases) knee OA. Three intra-articular (I.A) injections of PRP, 2 weeks a part, were received. Pain score and MRI Osteoarthritis Knee Score (MOAKS) were assessed. Serial synovial fluid cytokines assays in the form of Tumor necrosis factor-α (TNF-α) and Macrophage migration inhibitory factor (MIF), were performed using commercially available ELISA assay kits. The assays were performed pre-injection (S1), two weeks from the 1st I.A injection and two weeks from the 2nd I.A injection (S3) for all included patients.