Evaluation of Osteopontin (OPN) as Diagnostic Marker of Osteoarthritis (OA)

Abstract

In osteoarthritis, a joint disease there is progressive loss if articular cartilage that leads to loss of function and 
chronic pain in affected joints. Clinically presents as pain, stiffness ,decreased mobility ,crepitus and deformity of 
joints. The patients with osteoarthritis exhibit a higher level of osteopontin (OPN) in serum ,plasma and synovial fluids.A systemic review revealed that the OPN levels were markedly increased in plasma, serum and synovial 
fluids of patients with osteoarthritis. Therefore ,OPN levels are directly related to advancements in joint damage 
as well as progression of disease .OPN is a matrix glycoprotein that is expressed in response to tissue trauma 
.It in turns increase the activity of nuclear factor kabba B and other inflammatory mediators and enhance the 
inflammatory cascade.Reduction in levels if OPN halts the apoptosis if chondrocytes and angiogenesis .It can also 
be used as a biomarker in grading the progression and severity of osteoarthritis.
Radiography are gold standard investigations but on radiography, the damage is visualized after a long time in 
terms if loss of joint space. Biomarkers are used now for diagnostic and prognostic purposes. A study revealed 
that OPN levels are also increased in idiopathic hip Osteoarthritis so it can be used as a biochemical marker 
for diagnosing and determining the severity of disease. Biomarkers like OPN helps diagnosing the disease in 
early stages leading to earlier intervention. However ,further studies are still needed to to establish a strong 
connection.