Concise report: a minimal-invasive method to retrieve and identify entheseal tissue from psoriatic arthritis patients

Abstract

ObjectivesTo establish a minimally invasive biopsy technique for the analysis of entheseal tissue in patients with psoriatic arthritis (PsA).MethodsHuman cadavers were used for establishing the technique to retrieve tissue from the lateral humeral epicondyle enthesis (cadaveric biopsies). After biopsy, the entire enthesis was surgically resected (cadaveric resections). Biopsies and resections were assessed by label-free second harmonic generation (SHG) microscopy. The same technique was then applied in patients with PsA with definition of entheseal tissue by SHG, staining of CD45+immune cells and RNA extraction.ResultsEntheseal biopsies from five cadavers allowed the retrieval of entheseal tissue as validated by the analysis of resection material. Microscopy of biopsy and resection sections allowed differentiation of entheseal, tendon and muscle tissue by SHG and definition of specific intensity thresholds for entheseal tissue. In subsequent entheseal biopsies of 10 PsA patients: the fraction of entheseal tissue was high (65%) and comparable to cadaveric biopsies (68%) as assessed by SHG microscopy. Furthermore, PsA biopsies showed immune cell infiltration and sufficient retrieval of RNA for further molecular analysis.ConclusionEntheseal biopsy of the lateral epicondyle is feasible in patients with PsA allowing reliable retrieval of entheseal tissue and its identification by SHG microscopy.

Increased synovial immunohistochemistry reactivity of TGF-β1 in erosive peripheral psoriatic arthritis

“…That is why these results should be considered with caution and this study should be replicated with larger sample size. The findings in the synovial membrane will be more enriching in PsA together with the study of peripheral entheses and techniques for obtaining enthesis tissue samples for study are currently being perfected [ 40 , 41 ].…”

The Role of Neutrophils in Spondyloarthritis: A Journey across the Spectrum of Disease Manifestations

“…Obtaining enthesis specimens to perform histological and functional assays is challenging [ 30 ]; however, a new minimally invasive technique to perform entheseal biopsy of the elbow common extensor tendon was recently described. The authors not only showed the ability to sample proper entheseal tissue but also demonstrated the presence of CD45 + cells in the digested tissue [ 31 ]. This finding paves the way to the possibility of reaching a comprehensive characterization of the entheseal cellular environment.…”

Application of clinical and molecular profiling data to improve patient outcomes in psoriatic arthritis

“… 12 , 46 Furthermore, novel techniques such as lipidomics have revealed specific signatures in PsO and PsA. 18 , 47 Within HIPPOCRATES, several standardization projects have been started 48 and are underway to apply multi-omic approaches not only to provide the means for an earlier PsA diagnosis, but also to predict damage progression in established disease.…”