Role of placental growth factor and high resolution ultrasound in evaluation of hypervascularity in psoriatic arthritis

ABSTRACT

To measure the levels of placental growth factor [PIGF] in the serum and synovial fluid of in psoriatic arthritis [PsA] patients. Also, to evaluate any possible role of high resolution US in the angiogenesis observed in this disease. The study was conducted on 25 PsA patients and 10 apparently healthy age and sex matched subjects who served as controls. All subjects were subjected to thorough clinical and laboratory examination. PIGF levels were measured in the serum of all of them with ELISA technique. This was confirmed with Western blotting for PIGF in synovial fluid. Assessment of vascularity of the small joints of the hands and other affected knee joints with high resolution US was performed. The mean value of serum PIGF level in the serum of PsA patients was [66.52 +/- 12.44 pg/ml] and that in the synovial fluid was 79.82 +/- 14.92]. There was a highly statistical significant difference between them and serum/synovial fluid levels in controls [16.20 +/- 7.33 and 19.44 +/- 8.79 pg/ml] respectively [p<0.001]. Moreover, there was a highly significant association [p<0.001] and a statistically significant positive correlation [p<0.05] between serum and synovial fluid levels of PIGF in PsA patients. There was a statistically significant difference between PsA patients and controls as regard Hb levels, ESR and serum uric acid [p<0.05]. Also, there was a significant positive correlation between synovial fluid PIGF levels and the onset of joint affection [p<0.05]. High resolution US can measure the synovial thickness in the small joints of the hands as well as knee joints in PsA patient. It can also detect increased blood flow in joints, so can measure the resistive index and can detect effusion. Our results showed that there was a highly statistical significant difference between PsA patients and controls as regard synovial thickness [p<0.001]. Also, there was a significant negative correlation between serum PIGF and resistive index of PsA patients Angiogenesis plays an important role in the pathogenesis of PsA. This is confirmed by the presence of higher PIGF levels in both serum and synovial fluid. Inhibition of PIGF and its receptor [Flt-1] constitute potential candidates for therapeutic modulation of angiogenesis and inflammatory joint destruction in arthritis. High resolution ultrasound can be very useful to detect early hypervascularization and joint inflammation which guide treatment towards an early or more aggressive therapy