Heterogeneity in cytokine profile after intra-articular steroid treatment

Introduction

It is well known that intra-articular steroids are efficient and fast in reducing arthritis symptoms. However, treatment does not exclude long-term morbidity. Earlier studies have shown individual patterns in cytokine expression both inherently and in response to treatment. In this study we investigated the effect of ia steroids on the synovial tissue before and 10 days after treatment.

Patients and methods

Serial arthroscopical synovial biopsies were taken from patients with knee arthritis, before and ten days after ia triamcinolone injection. Biopsies were stained for histology, cytokines, cellmarkers and adhesion molecules using monoclonal antibodies, and measured by digital analysis or conventional counting of cells. Statistics were performed by Wilcoxon paired t-test.

Results

Almost all patients (10/11) improved clinically and macroscopically by arthroscopy. Only ICAM-1 and CD3 were significantly reduced. Very small amounts of TNF-producing cells were observed with a clear trend of reduction, but individual patterns were observed. No overall changes were observed for CD68/163, IL-1α or IL-1β.

Conclusion

This is the first study where the cytokine pattern has been analysed after intra-articular steroid injection and almost all patients improved clinically. However, there was no reduction in synovial macrophages, but T-cells as well as ICAM-1 diminished. No change in IL-1 was detected. TNFα producing cells were remarkably few with a trend to diminish, but individual patterns were seen. In this study, steroid treatment did effect the inflammation but it did not disappear completely microscopically as well as macroscopically. The therapeutic effects have mostly been short-lived and this study may provide an explanation for this.