Synovial fluid levels of fibroblast growth factor -2 and vascular endothelial growth factor in rheumatoid arthritis : correlation with disease activity and joint destruction

Abstract EN

Objective : to detect the synovial fluid levels of fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) in rheumatoid arthritis (RA) patients and compare them to those of osteoarthritis (OA) patients.

Also, to determine their correlation with disease activity and joint destruction.

Methodology : FGF-2 and VEGF were measured by ELISA in synovial fluid extracts obtained from 20 RA patients and 15 age and sex matched OA patients taken as controls.

The subjects underwent thorough clinical examination, assessment of disease activity using disease activity score (DAS), laboratory tests including ESR, complete blood picture and rheumatoid factor.

Radiographs of hands and wrists were taken then joint changes were evaluated using the Larsen’s score.

Results : 18 out of 20 RA patients (90 %) had elevated synovial fluid level of FGF-2 while 17 out of 20 RA patients (85 %) had elevated synovial fluid level of VEGF.

Synovial fluid levels of FGF-2 and VEGF in RA patients were 25 ± 5.2pg / ml and 650.23 ± 301.4 pg / ml, respectively and they were significantly higher than those in OA patients (FGF-2 = 3.5 ± 0.7 and VEGF = 280 ± 50.80) (p<0.001).

There was a statistically significant positive correlation between synovial fluid levels of FGF-2 and VEGF in RA patients (p < 0.05).

Also, there was a significant positive correlation between synovial fluid FGF-2 and VEGF levels and parameters of disease activity.

While there was a significant negative correlation between synovial levels of VEGF and age of the patients.

Regarding joint destruction, there was a highly significant difference (p < 0.001) between synovial fluid levels of FGF-2 and VEGF in subgroup -1 (RA patients with Larsen’s score < 50) and subgroup-2 (RA patients with Larsen’s score > 90).

Conclusion : the levels of synovial fluid FGF-2 and VEGF were found to be elevated in RA patients that might reflect their role in the pathogenesis of the disease.

Also, the correlation between elevation of synovial fluid levels of FGF-2 and that of synovial fluid level of VEGF reflect that these two factors may act synergistically.

The correlation of synovial fluid FGF-2 and VEGF levels with clinical parameters of RA and elevation of these factors in the RA patients with severe joint destruction may help in evaluation of progression or remission of the disease.