A Pilot Clinical Study of Hyperacute Serum Treatment in Osteoarthritic Knee Joint: Cytokine Changes and Clinical Effects

Abstract

The serum fraction of platelet-rich fibrin (hyperacute serum) has been shown to improve cartilage cell proliferation in in vitro osteoarthritic knee joint models. We hypothesize that hyperacute serum may be a potential regenerative therapeutic for osteoarthritic knees. In this study, the cytokine milieu at the synovial fluid of osteoarthritic knee joints exposed to hyperacute serum intraarticular injections was investigated. Patients with knee osteoarthritis received three injections of autologous hyperacute serum; synovial fluid was harvested before each injection and clinical monitoring was followed-up for 6 months. Forty osteoarthritic-related cytokines, growth factors and structural proteins from synovial fluid were quantified and analysed by Multivariate Factor Analysis. Hyperacute serum provided symptomatic relief regarding pain and joint stability for OA patients. Both patients "with" and "without effusion knees" had improved VAS, KOOS and Lysholm-Tegner scores 6 months after of hyperacute serum treatment. Synovial fluid analysis revealed two main clusters of proteins reacting together as a group, showing strong and significant correlations with their fluctuation patterns after hyperacute serum treatment. In conclusion, hyperacute serum has a positive effect in alleviating symptoms of osteoarthritic knees. Moreover, identified protein clusters may allow the prediction of protein expression, reducing the number of investigated proteins in future studies.

Keywords: KOOS; Lysholm-Tegner; VAS; cytokines; hyperacute serum; interleukin; knee osteoarthritis; matrix metalloprotease.

Figure 1

Schematic of the medical procedure. Firstly, when possible, synovial fluid was collected from the patient’s knee. Then, blood was taken and hyperacute serum was obtained from it. Hyperacute serum was finally intraarticularly injected.

Figure 2

Flow diagram of participant enrolment, allocation, follow-up and analysis of the study trial.

Figure 3

Graphs showing the Lysholm-Tegner (A), VAS (B) and KOOS (C) scores. Clinical data after 6-month follow-up after hyperacute serum treatment in OA knee at different time points: before the treatment, and after it at week 1, week 2, 3 months and 6 months. Red represents the clinical data from patients with effusion in the knees and black, without effusion.

Figure 4

Subgroups of investigated cytokines (n = 24) after principal component analysis. The factor analysis suggested 2 main factors one containing 11 and other 13 cytokines. With the help of the factor analysis, we were able to reduce the number of variables.

Figure 5

Pearson’s correlation heatmaps of the two identified protein groups after Multivariate Factor Analysis. Cytokines belonging to group A (left panel), presented strong to very strong correlation (p < 0.05), with the exception of resistin (A). Generally, group B (right panel) presented weaker correlations; however, the cluster including VEGF-A, ACAN, CCL3/MIP-1α, IL-22, IL-2, IL-23 and OSM were highly and significantly correlated (p < 0.05) (B). Color code represents positive or negative linear relationship between proteins, red and blue, respectively. White values indicate no shared trend between the proteins.

Figure 6

Protein–protein interaction analysis of the two identified groups by STRING database. Nodes represent proteins and the lines represent known interactions between the linked two proteins. The thickness of the lines indicates the confidence of the data which supports this interaction. Groups (A,B) are represented in the left and right panels, respectively. Color of nodes does not give information.