Nerve growth factor concentrations in the synovial fluid from healthy dogs and dogs with secondary osteoarthritis

OBJECTIVE: To measure the concentrations of nerve growth factor (NGF) in the synovial fluid from normal dogs and dogs with osteoarthritis (OA) secondary to common joint disorders. METHODS: Nerve growth factor synovial concentrations were measured by ELISA assay in 50 dogs divided into three groups: 12 healthy, 16 affected by acute lameness within seven days before enrolment, and 22 with chronic lameness persisting by more than one month before enrolment and accompanied by radiological signs of OA. Both acute and chronic lameness were secondary to orthopaedic diseases involving the shoulder, elbow and stifle joints. Nerve growth factor synovial concentrations were compared between means for healthy and acute groups and between the three groups using an F-test. Significance level was set at p <0.05. RESULTS: Nerve growth factor was detected in all canine synovial fluid samples. However, the mean synovial NGF concentration of healthy dogs (3.65 \ub1 2.18 pg/ml) was not significantly different from the mean value in dogs with acute lameness (6.45 \ub1 2.45 pg/ml) (p = 0.79). Conversely, the mean synovial NGF concentration in dogs with chronic lameness (20.19 \ub1 17.51 pg/ml) was found to be significantly higher than that found in healthy dogs (p