A novel mice model of acute flares in osteoarthritis elicited by intra-articular injection of cultured mast cells

Degradomics defines proteolysis information flow from human knee osteoarthritis cartilage to matched synovial fluid and the contributions of secreted proteases ADAMTS5, MMP13 and CMA1 to articular cartilage breakdown

OBJECTIVES

Proteolytic cartilage extracellular matrix breakdown is a major mechanism of articular cartilage loss in osteoarthritis (OA) pathogenesis. We sought to determine the overlap of proteolytic peptides in matched knee OA cartilage and synovial fluid on a proteome-wide scale to increase the prospective biomarker repertoire and to attribute proteolytic cleavages to specific secreted proteases.

DESIGN

Matched human knee OA cartilage and synovial fluid (n = 5) were analyzed by N-terminomics using Terminal Amine Isotopic Labeling of Substrates (TAILS), comprising labeling and enrichment of protein N-termini, high-resolution mass spectrometry and positional peptide mapping. Donor non-OA articular cartilage was digested with CMA1, MMP13 or ADAMTS5, and TAILS was used to identify cleavage sites, which were matched against cartilage and synovial fluid degradomes.

RESULTS

Of over 20,000 cleaved peptides in the combined OA cartilage and synovial fluid degradomes, 677 peptides, originating from 153 proteins, were present in all cartilage and synovial fluid samples. CMA1, MMP13 and ADAMTS5 digestion of cartilage identified numerous cleavage sites for each protease and distinct cleavage site preferences. Peptides resulting from the activities of these proteases were detected in OA cartilage and synovial fluid.

CONCLUSIONS

Proteolytic fragments from both cartilage and circulating proteins are detectable by synovial fluid degradomics. CMA1, MMP13 and ADAMTS5 activity profiles in cartilage are distinct from each other and the previously determined HtrA1 profile. This work expands the proteolytic biomarker space for OA investigation, suggests that multiple, diverse proteases contribute to cartilage destruction, and demonstrates that their specific contributions can each be defined by multiple biomarkers.

Antihistamine use and osteoarthritis or joint pain

OBJECTIVES

Antihistamines have been reported to be linked with less pain in osteoarthritis. We aimed to estimate associations between antihistamine use and three outcomes: prevalent osteoarthritis, current joint pain, and developing osteoarthritis.

METHODS

We included 25 003 participants of EpiHealth - a cohort of persons aged 45 to 75 from Malmö/Uppsala in Sweden. Participants self-reported the presence of allergy, joint pain and osteoarthritis at a study visit between years 2010 and 2016. Further, we obtained data about diagnoses of allergy and osteoarthritis from health-care registers (primary, specialist and inpatient care). Exposure was prescribed dispensed antihistamines (H1-antagonists) during ∼6 years preceding the EpiHealth visit retrieved from the Prescribed Drugs Register. The outcomes were osteoarthritis (any location), pain in knees/hips/hands-wrists at the examination (cross-sectional) and future incident diagnosis of osteoarthritis (longitudinal, in a cohort free of osteoarthritis at EpiHealth). We report risk ratios (95% confidence intervals [CI]) from logistic regression and hazard ratios (HR) from Cox regression, from models adjusted for age, sex, body mass index, allergy and use of healthcare. We used prescribed dispensed penicillin as negative control.

RESULTS

The associations between use of antihistamines and osteoarthritis/joint pain at EpiHealth were 1.13 (95%CI 1.06, 1.20) and 1.02 (0.99, 1.05), respectively. The HR of future incident osteoarthritis diagnosis with use of antihistamines was 1.15 (1.03, 1.28). The association (HR) between penicillin use and future incident osteoarthritis diagnosis was 1.16 (1.07, 1.25).

CONCLUSIONS

In a large population-based observational cohort, use of antihistamines was neither associated with less joint pain/osteoarthritis nor lower risk of future osteoarthritis.

A significant difference of synovial mast cells in synovium from rotator cuff arthropathy compared to rotator cuff tears: A histological pilot study

Objective

Aim of the present study was to compare the presence of Mast Cells (MCs) in synovial samples from gleno-humeral osteoarthritis (OA) and from control group.

Methods

Synovial tissue samples were obtained during arthroplasty from 23 patients with gleno-humeral OA due to rotator cuff arthropathy (RCA) and from 20 patients without OA, constituting OA group and control group respectively. Before surgery self-reported pain was assessed using VAS score and OSS was used to value functional ability. Shoulder radiograph (Antero-posterior, Y-view and Grashey views) was evaluated by musculoskeletal radiologist and graded according to modified Samilson-Prieto classification.Synovial tissue, obtained during arthroplasty and arthroscopic procedure, was prepared to immunohistochemical analysis with anti-CD31 and anti-CD117 antibodies, to detect respectively endothelial cells and MCs at 40x magnification. Synovitis scores have been assessed. Under the control of the image processing system the distribution and the total number of vessels and MCs were determined.

Results

The numbers of MCs and the area fraction (20x magnification) occupied by them were significantly higher in OA samples than in control tissue. The synovitis score was higher in OA patients with a positive correlation. Vessels number and area fraction were higher in OA patients than in controls. Analysis of MC number in relation to clinical data indicated positive correlation with the VAS score.

Conclusions

The distribution of MCs on synovium significantly differ between OA and control groups. Despite the design of the study could not conclude the cause-effect relationship, the presence of MCs might have role in OA pathogenesis.

Level of evidence

Histological study.

Evaluating the baseline hemoglobin, albumin, lymphocyte, and platelet (HALP) score in the United States adult population and comorbidities: an analysis of the NHANES

Introduction

As a composite immunonutritional biomarker, the Hemoglobin, Albumin, Lymphocyte, Platelet (HALP) score has shown promise in assessing a patient's overall health status by integrating several routinely collected laboratory indicators. This biomarker has been examined in many different populations of patients and disease states (i.e., cancer), but an integrated, universal rubric using standardized thresholds has not thus far been developed. Pre-existing large population-based databases represent an ideal source to examine the distribution of HALP and the influence of diverse health statuses on this score.

Methods

We conducted a cross-sectional study using data from the National Health and Nutrition Examination Survey (NHANES) between 2017-2020, evaluating 8,245 participants across numerous demographic, socioeconomic, and health-related variables. Univariate and multivariate linear regression analyses assessed the associations between HALP scores and these factors.

Results

Our findings revealed significant associations between HALP scores and various demographic, socioeconomic, and health conditions. The median HALP score among the representative population was 49.0, with varying median scores across different groups and normal reference ranges for males and females. Multivariate regression analysis showed that anemia treatment, age over 65 years, weak/failing kidneys, and cancer were independent risk factors associated with lower HALP scores. Male participants demonstrated higher HALP scores than female participants, and age was inversely related to HALP. Moreover, HALP scores were negatively associated with the number of comorbidities.

Conclusion/discussion

This study set out to explore the HALP score from a population-based perspective, uncovering notable associations that offer vital insights into the score's clinical relevance and future applications. By determining a median HALP score of 49.0 and normal reference ranges within our diverse, representative sample, we establish a robust foundation for researchers to refine optimal HALP applications and thresholds. Considering the growing focus on personalized medicine, HALP holds promise as a prognostic tool, enabling clinicians to comprehend their patients' immunonutritional status better and deliver customized care.

Synovial mast cells from knee and hip osteoarthritis: histological study and clinical correlations

PURPOSE

The aim of this study was to investigate the presence of synovial mast cells (MCs) in hip and knee tissue from osteoarthritis (OA) patients and to correlate them with clinical and radiological data.

METHODS

Synovial tissue was obtained during arthroplasty from 60 patients, 30 with knee OA and 30 with hip OA. Control synovial tissue was obtained from 30 patients without OA, 15 undergoing above-knee amputation and 15 receiving a hip replacement for fracture. Before surgery, the radiographic findings were graded according to the Kellgren-Lawrence system and clinical data including pain (VAS) and functional information (KOOS and HOOS) was collected. The tissue was stained with hematoxylin-eosin and toluidine blue for histochemistry and incubated with CD117 and CD31 antibodies for immunohistochemistry. MC and vessel number and synovitis score were determined in all samples.

RESULTS

Mean MC number, synovitis score and vessel number were significantly higher in the OA samples (p < 0.05) than in control tissue. MC number correlated with the synovitis score and disease severity in both patient groups.

CONCLUSIONS

The prevalence of MCs in synovium from OA patients and their association with synovial inflammation and pain suggest a role for them in OA pathophysiology.