ABSTRACT
<p><b>INTRODUCTION</b>Osteoarthritis (OA) is a progressive degenerative disorder of the articular cartilage. Available diagnostic radiography has been poorly associated with the progress and severity of this clinical disease. As osteogenic protein-1 (OP-1) has been identified as a bone morphogenetic protein with a major role in cartilage repair, we aimed to evaluate its potential role in the diagnosis of OA.</p><p><b>METHODS</b>This was an experimental study conducted at the Department of Biochemistry, Sikkim Manipal Institute of Medical Sciences, India. Polyclonal antibodies (i.e. anti-OP-1[f]) were raised against OP-1 in mice, and subsequently used in a sandwich enzyme-linked immunosorbent assay (ELISA) to detect the presence of OP-1 in the synovial fluids of 75 osteoarthritic patients. For the purpose of correlation, the radiographic assessments of the knees of the 75 patients were graded using the Kellgren-Lawrence scoring system.</p><p><b>RESULT</b>The polyclonal antibody (i.e. anti-OP-1[f]) raised against OP-1 was able to detect the presence of OP-1 in the synovial fluids of all the osteoarthritic patients via sandwich ELISA. The level of the OP-1 was found to be much higher than the reference range and correlated positively with the severity of OA (r = 0.24; p = 0.04).</p><p><b>CONCLUSION</b>Our study shows that the polyclonal antibody, anti OP-1(f), could be used for the immunodiagnosis of osteoarthritis via sandwich ELISA.</p>