Inflammation Is Present in Early Human Tendinopathy
Two articles on PainSci cite Millar 2010: 1. Icing for Injuries, Tendinitis, and Inflammation 2. Tennis Elbow Guide
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
BACKGROUND: The cellular mechanisms of tendinopathy remain unclear particularly with respect to the role of inflammation in early disease. The authors previously identified increased levels of inflammatory cytokines in an early human model of tendinopathy and sought to extend these studies to the cellular analysis of tissue.
PURPOSE: To characterize inflammatory cell subtypes in early human tendinopathy, the authors explored the phenotype and quantification of inflammatory cells in torn and control tendon samples. Design Controlled laboratory study.
METHODS: Torn supraspinatus tendon and matched intact subscapularis tendon samples were collected from 20 patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from 10 patients undergoing arthroscopic stabilization surgery. Tendon biopsy samples were evaluated immunohistochemically by quantifying the presence of macrophages (CD68 and CD206), T cells (CD3), mast cells (mast cell tryptase), and vascular endothelium (CD34).
RESULTS: Subscapularis tendon samples obtained from patients with a torn supraspinatus tendon exhibited significantly greater macrophage, mast cell, and T-cell expression compared with either torn supraspinatus samples or control subscapularis-derived tissue (P < .01). Inflammatory cell infiltrate correlated inversely (r = .5; P < .01) with rotator cuff tear size, with larger tears correlating with a marked reduction in all cell lineages. There was a modest but significant correlation between mast cells and CD34 expression (r = .4; P < .01) in matched subscapularis tendons from shoulders with supraspinatus ruptures.
CONCLUSION: This study provides evidence for an inflammatory cell infiltrate in early mild/moderate human tendinopathy. In particular, the authors demonstrate significant infiltration of mast cells and macrophages, suggesting a role for innate immune pathways in the events that mediate early tendinopathy.
CLINICAL RELEVANCE: Further mechanistic studies to evaluate the net contribution and hence therapeutic utility of these cellular lineages and their downstream processes may reveal novel therapeutic approaches to the management of early tendinopathy.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.
- Inciting events associated with lumbar disc herniation. Suri 2010 Spine J.
- Prediction of an extruded fragment in lumbar disc patients from clinical presentations. Pople 1994 Spine (Phila Pa 1976).
- Characteristics of patients with low back and leg pain seeking treatment in primary care: baseline results from the ATLAS cohort study. Konstantinou 2015 BMC Musculoskelet Disord.
- Effectiveness and cost-effectiveness of universal school-based mindfulness training compared with normal school provision in reducing risk of mental health problems and promoting well-being in adolescence: the MYRIAD cluster randomised controlled trial. Kuyken 2022 Evid Based Ment Health.