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BackgroundAnterior cruciate ligament tears can lead to posttraumatic osteoarthritis. In addition to biomechanical factors, changes in biochemical profiles within the knee joint after injury and anterior cruciate ligament reconstruction (ACLR) may play a role in accelerating joint degeneration. Hypothesis/Purpose: It was hypothesized that cartilage matrix composition after ACLR is associated with the degree of inflammatory response after initial injury. This study evaluated the association between the inflammatory response after injury-as indicated by cytokine, metalloproteinase, and cartilage degradation marker concentrations in synovial fluid-and articular cartilage degeneration, measured by T1ρ and T2 quantitative magnetic resonance imaging up to 3 years after ACLR.Study designCohort study; Level of evidence, 2.MethodsTwenty-six subjects from a longitudinal cohort study who underwent ACLR at a mean 8.5 weeks after injury (range, 4-19 weeks) had synovial fluid aspirated at the time of surgery. Immunoassays quantified biomarkers in synovial fluid. T1ρ and T2 values of articular cartilage were calculated with magnetic resonance scans acquired prior to surgery and at 6 months and 1, 2, and 3 years after surgery. Pearson correlation coefficients were calculated among the various biomarkers. K-means clustering was used to group subjects with similar biomarker profiles. Generalized estimating equations were used to find the overall differences in T1ρ and T2 values throughout these first 3 years after surgery between the clusters while controlling for other factors.ResultsSignificant and strong correlations were observed between several cytokines (interleukin 6 [IL-6], IL-8, IL-10, and tumor necrosis factor α) and 2 matrix metalloproteinases (MMP-1 and MMP-3) ( P < .05). Moderate correlations were found among combinations of C-terminal crosslinked telopeptide type II collagen, N-terminal telopeptide, cartilage oligomeric matrix protein, and sulfated glycosaminoglycan ( P < .05). Two clusters were generated, 1 of which was characterized by lower concentrations of cytokines (IL-6, IL-8, IL-10, tumor necrosis factor α) and MMP-1 and MMP-3 and higher sulfated glycosaminoglycan. This cluster was associated with significantly higher T1ρ and T2 values in the medial tibial and patellar cartilage over the first 3 years after ACLR.ConclusionAt the time of ACLR surgery, profiles of synovial fluid inflammatory cytokines, degradative enzymes, and cartilage breakdown products show promise as predictors of abnormal cartilage tissue integrity (increased T1ρ and T2 values) throughout the first 3 years after surgery.Clinical relevanceThe results suggest an intricate relationship between inflammation and cartilage turnover, which can in turn be influenced by timing after injury and patient factors.

Objectives: To identify age-related plasma extracellular vehicle (EVs) phenotypes in healthy adults. Methods: EV proteomics by high-resolution mass spectrometry to evaluate EV protein stability and discover age-associated EV proteins (n=4 with 4 serial freezethaws each); validation by high-resolution flow cytometry and EV cytokine quantification by multiplex ELISA (n=28 healthy donors, aged 18-83 years); quantification of WI-38 fibroblast cell proliferation response to co-culture with PKH67-labeled young and old plasma EVs. The EV samples from these plasma specimens were previously characterized for bilayer structure, intra-vesicle mitochondria and cytokines, and hematopoietic cell-related surface markers. Results: Compared with matched exo-EVs (EV-depleted supernatants), endo-EVs (EV-associated) had higher mean TNF-a and IL-27, lower mean IL-6, IL-11, IFN-g, and IL-17A/F, and similar mean IL-1b, IL-21, and IL-22 concentrations. Some endo-EV and exo-EV cytokine concentrations were correlated, including TNF-a, IL-27, IL-6, IL-1b, and IFN-g, but not IL-11, IL-17A/F, IL-21 or IL-22. Endo-EV IFN-g and exo-EV IL-17A/F and IL-21 declined with age. By proteomics and confirmed by flow cytometry, we identified age-associated decline of fibrinogen (FGA, FGB and FGG) in EVs. Age-related EV proteins indicated predominant origins in the liver and innate immune system. WI-38 cells (>95%) internalized similar amounts of young and old plasma EVs, but cells that internalized PKH67-EVs, particularly young EVs, underwent significantly greater cell proliferation. Conclusion: Endo-EV and exo-EV cytokines function as different biomarkers. The observed healthy aging EV phenotype reflected a downregulation of EV fibrinogen subpopulations consistent with the absence of a pro-coagulant and pro-inflammatory condition common with age-related disease. [ABSTRACT FROM AUTHOR]

Objective: To compare a remotely supervised weight loss and exercise intervention to lifestyle counseling for effects on cardiovascular disease risk, disease activity, and patient‐reported outcomes in older patients with rheumatoid arthritis (RA) and overweight/obesity. Methods: Twenty older (60–80 years), previously sedentary participants with seropositive RA and overweight/obesity were randomized to 16 weeks of either Supervised Weight loss and Exercise Training (SWET) or Counseling Health As Treatment (CHAT). The SWET group completed aerobic training (150 minutes/week moderate‐to‐vigorous intensity), resistance training (two days/week), and a hypocaloric diet (7% weight loss goal). The CHAT control group completed two lifestyle counseling sessions followed by monthly check‐ins. The primary outcome was a composite metabolic syndrome z‐score (MSSc) derived from fasting glucose, triglycerides, high density lipoprotein–cholesterol, minimal waist circumference, and mean arterial pressure. Secondary outcomes included RA disease activity and patient‐reported outcomes. Results: Both groups improved MSSc (absolute change −1.67 ± 0.64 in SWET; −1.34 ± 1.30 in CHAT; P < 0.01 for both groups) with no between‐group difference. Compared with CHAT, SWET significantly improved body weight, fat mass, Disease Activity Score‐28 C‐reactive protein, and patient‐reported physical health, physical function, mental health, and fatigue (P < 0.04 for all between‐group comparisons). Based on canonical correlations for fat mass, cardiorespiratory fitness, and leg strength, component‐specific effects were strongest for (1) weight loss improving MSSc, physical health, and mental health; (2) aerobic training improving physical function and fatigue; and (3) resistance training improving Disease Activity Score‐28 C‐reactive protein. Conclusion: In older patients with RA and overweight/obesity, 16 weeks of remotely supervised weight loss, aerobic training, and resistance training improve cardiometabolic health, patient‐reported outcomes, and disease activity. Less intensive lifestyle counseling similarly improves cardiovascular disease risk profiles, suggesting an important role for integrative interventions in the routine clinical care of this at‐risk RA population. [ABSTRACT FROM AUTHOR]

Objective: Human and in vivo animal research implicates inflammation following articular fracture as contributing to post-traumatic arthritis. However, relevant immune cell subsets present following injury are currently undefined. Immunophenotyping human and murine synovial fluid may help to identify immune cell populations that play key roles in the response to articular fracture.Methods: Immunophenotyping by polychromatic flow cytometry was performed on human and mouse synovial fluid following articular fracture. Specimens were collected in patients with closed ankle fracture at the time of surgical fixation and from C57BL/6 mice with closed articular knee fracture. Immune cells were collected from injured and uninjured joints in mice via a novel cell isolation method. Whole blood samples were also collected. Immunohistochemistry (IHC) was performed on mouse synovial tissue to assess for macrophages and T cells.Results: Following intra-articular fracture, the prominent human synovial fluid immune cell subset was CD3+ T cells, containing both CD4+ and CD8+ T cells. In mice, infiltration of CD45+ immune cells in synovial fluid of the fractured limb was dominated by CD19+ B cells and CD3+ T cells at 7 days after intra-articular fracture. We also detected adaptive immune cells, including macrophages, NK cells, dendritic cells and monocytes. Macrophage and T cell findings were supported by IHC of murine synovial tissue.Conclusions: Determining specific cell populations that mediate the immune response is essential to elucidating the chain of events initiated after injury and may be an important step in identifying potential immune signatures predictive of PTA susceptibility or potential therapeutic targets. [ABSTRACT FROM AUTHOR]