Background: The aim of this review is to investigate systematically the presence of the
most extensively studied Synovial Fluid (SF) and/or serum markers in patients with Rheumatoid
Arthritis (RA), Psoriatic Arthritis (PsA) and Osteoarthritis (OA), and their associations and
correlations with laboratory and clinical data, with a view to providing insights for future research.
Objective: Papers were selected using the PRISMA flow-chart. Search of the electronic databases
according to the above criteria found a total of 55 papers. Examination led to the exclusion of 39 papers.
Finally, 16 studies met the inclusion criteria and are reviewed. As regards to interleukins we
found: Higher TNF-α levels in patients with early RA and PsA than in those with osteoarthritis
(p<0.05); higher IL-6 levels in patients with inflammatory arthritis (RA and PsA) than in those with
OA (p=0.032) and higher IL-17 levels in SF from PsA patients than RA patients (p=0.04) and a significant
difference in serum levels between PsA patients and healthy controls (p=0.013) and higher
IL-22 SF levels in PsA than OA patients (p<0.001) and in RA compared with OA patients (p<0.01).
As regards chemokine, CCL-22 was higher in SF from RA and PsA patients than in OA patients
Method: Considering the sample size of the studies reviewed here, their findings need confirmation in
larger samples, while the potential prognostic value of SF and/or serum biomarkers requires prospective
Conclusion: The limitations of the biological SF assays and the problems encountered in the
attempted use of cytokine assays for diagnostic purposes must be addressed.