Changes in concentrations of haemostatic and inflammatory biomarkers in synovial fluid after intra-articular injection of lipopolysaccharide in horses.
Authors: Andreassen Stine Mandrup, Vinther Anne Mette Lindberg, Nielsen Søren Saxmose, Andersen Pia Haubro, Tnibar Aziz, Kristensen Annemarie T, Jacobsen Stine
Journal: BMC veterinary research
Summary
# Editorial Summary Septic arthritis remains one of the most clinically challenging conditions in equine practice, yet our understanding of joint pathology has traditionally centred on inflammatory markers alone—a gap this research addresses by investigating the simultaneous activation of both haemostatic and inflammatory pathways within the joint space. Researchers induced experimental joint inflammation in six horses by injecting lipopolysaccharide (LPS) into the antebrachiocarpal joint, then tracked changes in synovial fluid and blood across a 144-hour period, measuring key biomarkers including total protein, white blood cell counts, acute phase proteins (serum amyloid A and haptoglobin), iron, fibrinogen, and coagulation markers (thrombin-antithrombin complexes and d-dimer). The study demonstrated that LPS injection triggered a marked inflammatory response within hours, with synovial fluid white blood cell counts and protein concentrations rising substantially, whilst haemostatic markers including fibrinogen and d-dimer also increased significantly, indicating concurrent activation of clotting pathways within the inflamed joint compartment. These findings suggest that septic or inflammatory arthritis involves interplay between coagulation and inflammation that has previously been underappreciated in equine medicine; clinicians should recognise that fibrin deposition and clot formation are integral to the pathophysiology rather than mere secondary phenomena. Understanding this dual activation may inform future therapeutic strategies, particularly regarding the potential role of anticoagulant or fibrinolytic treatments alongside conventional anti-inflammatory protocols in managing severe joint disease.
Read the full abstract on PubMed
Practical Takeaways
- •Monitor both inflammatory and coagulation biomarkers in joint fluid when diagnosing septic arthritis—elevated d-dimer and TAT alongside protein/WBC provide more complete picture of joint pathology
- •Early intervention within first 2-4 hours post-infection is critical as biomarker changes occur rapidly; clinical lameness may lag behind biochemical changes
- •Consider anti-coagulation or fibrinolytic therapy alongside anti-inflammatory treatment in septic joints, as fibrin deposition contributes to joint damage
Key Findings
- •LPS injection induced significant increases in synovial fluid total protein, WBC, SAA, and haptoglobin within 2-4 hours post-injection
- •Haemostatic markers (TAT and d-dimer) were elevated in synovial fluid, indicating activation of coagulation cascade alongside inflammatory response
- •Peak inflammatory response occurred at 24-48 hours post-injection with clinical lameness correlating to biomarker changes
- •Both haemostatic and inflammatory pathways are concurrently activated in equine septic arthritis, not inflammation alone