PMID- 28957567 OWN - NLM STAT- MEDLINE DCOM- 20171006 LR - 20180504 IS - 1462-0332 (Electronic) IS - 1462-0324 (Linking) VI - 56 IP - 10 DP - 2017 Oct 1 TI - Infrapatellar fat pad features in osteoarthritis: a histopathological and molecular study. PG - 1784-1793 LID - 10.1093/rheumatology/kex287 [doi] AB - OBJECTIVE: The infrapatellar fat pad (IFP) is considered a local producer of adipocytokines, suggesting a potential role in OA. The objective of this study was to evaluate the histopathological and molecular characteristics of OA IFPs compared with controls. METHODS: The histopathological characteristics of IFPs were evaluated in patients undergoing total knee replacements and in control patients (without OA), considering the following parameters: presence of inflammatory cells, vascularization, adipose lobules dimension and thickness of the interlobular septa. Immunohistochemistry was performed to evaluate VEGF, monocyte chemotactic protein 1 (MCP-1) and IL-6 proteins. Quantitative real time PCR was performed to evaluate the expression levels of adipocytokines in the OA IFPs. RESULTS: OA IFPs showed an increase in inflammatory infiltration, vascularization and thickness of the interlobular septa compared with controls. VEGF, MCP-1 and IL-6 proteins were higher in OA IFPs compared with in controls. Inflammatory infiltration, hyperplasia, vascularization and fibrosis were increased in OA IFP synovial membranes compared with in those of controls. VEGF protein levels were associated with an increased number of vessels in the OA IFPs, while MCP-1 and IL-6 protein levels were associated with higher grades of inflammatory infiltration. Leptin levels were positively correlated with adiponectin and MCP-1expression, while adiponectin positively correlated with peroxisome proliferative activated receptor gamma, MCP-1 and IFP vascularity. MCP-1 showed a positive correlation with peroxisome proliferative activated receptor gamma. IFP lobules dimensions were positively correlated with IL-6 expression and negatively with thickness of interlobular septa. VEGF mRNA levels were positively correlated with increased synovial vascularity. CONCLUSIONS: OA IFPs and synovial membranes are more inflamed, vascularized and fibrous compared with those of control patients (without OA). CI - (c) The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com FAU - Favero, Marta AU - Favero M AD - Rheumatology Unit, Department of Medicine - DIMED, University Hospital of Padova, Padova. AD - Laboratory of Immunorheumatology and Tissue Regeneration/RAMSES, Rizzoli Orthopedic Research Institute, Bologna. FAU - El-Hadi, Hamza AU - El-Hadi H AD - Department of Medicine - DIMED, School of Medicine, Clinica Medica 3. FAU - Belluzzi, Elisa AU - Belluzzi E AD - Rheumatology Unit, Department of Medicine - DIMED, University Hospital of Padova, Padova. FAU - Granzotto, Marnie AU - Granzotto M AD - Department of Medicine - DIMED, School of Medicine, Clinica Medica 3. FAU - Porzionato, Andrea AU - Porzionato A AD - Institute of Human Anatomy, Department of Neurosciences, University of Padova. FAU - Sarasin, Gloria AU - Sarasin G AD - Institute of Human Anatomy, Department of Neurosciences, University of Padova. FAU - Rambaldo, Anna AU - Rambaldo A AD - Institute of Human Anatomy, Department of Neurosciences, University of Padova. FAU - Iacobellis, Claudio AU - Iacobellis C AD - Orthopaedic Clinic, Department of Surgery, Oncology and Gastroenterology, University-Hospital of Padova. FAU - Cigolotti, Augusto AU - Cigolotti A AD - Orthopaedic Clinic, Department of Surgery, Oncology and Gastroenterology, University-Hospital of Padova. FAU - Fontanella, Chiara Giulia AU - Fontanella CG AD - Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy. FAU - Natali, Arturo AU - Natali A AD - Centre for Mechanics of Biological Materials, University of Padova, Padova, Italy. FAU - Ramonda, Roberta AU - Ramonda R AD - Rheumatology Unit, Department of Medicine - DIMED, University Hospital of Padova, Padova. FAU - Ruggieri, Pietro AU - Ruggieri P AD - Orthopaedic Clinic, Department of Surgery, Oncology and Gastroenterology, University-Hospital of Padova. FAU - De Caro, Raffaele AU - De Caro R AD - Institute of Human Anatomy, Department of Neurosciences, University of Padova. FAU - Vettor, Roberto AU - Vettor R AD - Department of Medicine - DIMED, School of Medicine, Clinica Medica 3. FAU - Rossato, Marco AU - Rossato M AD - Department of Medicine - DIMED, School of Medicine, Clinica Medica 3. FAU - Macchi, Veronica AU - Macchi V AD - Institute of Human Anatomy, Department of Neurosciences, University of Padova. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't PL - England TA - Rheumatology (Oxford) JT - Rheumatology (Oxford, England) JID - 100883501 RN - 0 (ADIPOQ protein, human) RN - 0 (Adipokines) RN - 0 (Adiponectin) RN - 0 (CCL2 protein, human) RN - 0 (Chemokine CCL2) RN - 0 (IL6 protein, human) RN - 0 (Interleukin-6) RN - 0 (VEGFA protein, human) RN - 0 (Vascular Endothelial Growth Factor A) SB - IM MH - Adipokines/analysis MH - Adiponectin/analysis MH - Adipose Tissue/blood supply/metabolism/*pathology MH - Aged MH - Aged, 80 and over MH - Arthroplasty, Replacement, Knee MH - Case-Control Studies MH - Chemokine CCL2/analysis MH - Female MH - Humans MH - Interleukin-6/analysis MH - Knee Joint/blood supply/metabolism/pathology MH - Male MH - Middle Aged MH - Osteoarthritis, Knee/metabolism/*pathology/surgery MH - Patella/blood supply/metabolism/*pathology MH - Synovial Membrane/blood supply/metabolism/pathology MH - Vascular Endothelial Growth Factor A/analysis OTO - NOTNLM OT - infrapatellar fat pad OT - knee OT - osteoarthritis OT - total knee replacement EDAT- 2017/09/29 06:00 MHDA- 2017/10/07 06:00 CRDT- 2017/09/29 06:00 PHST- 2016/10/13 00:00 [received] PHST- 2017/09/29 06:00 [entrez] PHST- 2017/09/29 06:00 [pubmed] PHST- 2017/10/07 06:00 [medline] AID - 4056490 [pii] AID - 10.1093/rheumatology/kex287 [doi] PST - ppublish SO - Rheumatology (Oxford). 2017 Oct 1;56(10):1784-1793. doi: 10.1093/rheumatology/kex287.