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Histologic evidence for a humoral immune response in synovitis associated with cranial cruciate ligament disease in dogs
Author(s) -
Kuroki Keiichi,
Williams Ned,
Cook James L.
Publication year - 2021
Publication title -
veterinary surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 79
eISSN - 1532-950X
pISSN - 0161-3499
DOI - 10.1111/vsu.13600
Subject(s) - synovitis , medicine , histopathology , immune system , pathology , osteoarthritis , cruciate ligament , rheumatoid arthritis , anterior cruciate ligament , immunology , surgery , alternative medicine
Objective To investigate histopathological features of synovium from dogs with cranial cruciate ligament disease (CCLD) to seek mechanisms of osteoarthritis (OA) associated with CCLD. Study design Retrospective, single‐institution case series. Animals Thirty client‐owned dogs. Methods Synovial biopsies (n = 30) obtained from stifles with CCLD were assessed by using two synovitis histopathology grading systems (Krenn and Hospital for Special Surgery [HSS]). The Krenn synovitis score was interpreted as “no synovitis,” “low‐grade,” or “high‐grade,” while inflammatory subtype (low, mixed, or high) was determined by a computational algorithm within the HSS system. Comparison of synovitis scores was based on degree of CCL rupture and presence of meniscal tears. Results Histopathological changes and synovitis scores were similar regardless of degree of rupture (partial n = 5, complete n = 25) or presence of meniscal injury (n = 12) and were characterized by hyperplastic and lymphoplasmacytic synovitis with increased vascularity (30/30) and the presence of hemosiderin deposits (28/30), binucleated plasma cells (28/30), mucoid change (25/30), and Mott cells (16/30). Thirteen (43%) specimens were consistent with high‐grade synovitis according to the Krenn system, while 11 (37%) specimens fit into the high‐inflammatory subtype with the HSS system. Conclusion Synovitis associated with canine CCLD in this study population was lymphoplasmacytic and was often highly inflammatory, with the presence of cells pertaining to humoral immunity. Humoral immune responses may play key roles in the synovitis associated with CCLD. Clinical significance Modulation of biological factors that provoke humoral immune responses may mitigate symptoms of OA that persist and progress even after surgical treatment of CCLD in dogs.