Serum and synovial fluid levels of vascular endothelial growth factor in rheumatoid arthritis: correlation with disease activity

ABSTRACT

To study serum and synovial fluid levels of vascular endothelial growth factor [VEGF] in Rheumatoid arthritis [RA] and to investigate its association with clinical and laboratory parameters in order to assess its value as a marker of disease activity and development of joint synovitis. Measurement of VEGF levels in serum of 40 RA patients, synovial fluid obtained from 15 patients of them and 10 healthy age and sex matched subjects taken as controls using enzyme linked immunosorbent assay [ELISA] technique. Subjects underwent thorough clinical examination, assessment of disease activity using disease activity score [DAS] and radiological evaluation using the Larsen scale. Serum VEGF levels in RA patients [436.5 +/- 286.3 pg/ml] and that in synovial fluid [640.7 +/- 305.4 pg/ml] were significantly higher than in controls [252.0 +/- 51.6 and 276.0 +/- 48.8 pg/ml] respectively [p<0.001]. Twenty two RA patients out of 40 [55%] had increased serum VEGF while 14 RA patients out of 15 [93.3%] had increased synovial fluid VEGF There was a highly significant difference between serum VEGF [590.9 +/- 303.2 pg/ml] and synovial fluid VEGF [756.0 +/- 313.8 pg/ml] of RA patients [p<0.001]. Moreover, there was a statistically significant positive correlation between serum and synovial fluid VEGF [p<0.05] of RA patients. Also, there was a highly significant difference [p<0.001] and a significant positive correlation [<0.05] between serum VEGF and 28 swollen joint count, ESR, DAS score and Larsen grades. Again, there was a statistically significant difference [p<0.05] and significant positive correlation [p<0.05] between serum VEGF and age and 28 tender joint count while there was a significant negative correlation with Hb level [p<0.05]. Serum and synovial fluid VEGF levels were increased in RA patients and reflect the extent of joint disease severity. So VEGF levels can be a reliable marker in assessment of early active joint destruction in RA patients and evaluate the antiangiogenic therapy especially with VEGF inhibitors, which can represent a novel therapy for RA in the future