Prolonged morning stiffness is common in hand OA and does not preclude a diagnosis of hand osteoarthritis.

OBJECTIVE: Prolonged morning stiffness (>60 min) is considered a symptom of inflammatory arthritis, but has a poor discriminative ability. Knowledge about morning stiffness in patients with hand osteoarthritis (OA) is lacking. We therefore studied morning stiffness in patients with hand OA. DESIGN: Patients with primary hand OA according to their treating rheumatologist in the Hand OSTeoArthritis in Secondary care (HOSTAS) cohort were studied. Severity of morning stiffness was examined with Australian/Canadian hand OA index (AUSCAN) and presence and duration of morning stiffness were examined with a standardized questionnaire. Association of patient and disease characteristics with prolonged morning stiffness (>60 min) were analyzed with logistic regression. RESULTS: In total 519 of 538 patients had available data about duration of morning stiffness, of whom 89 (17%) had prolonged morning stiffness. Severity of stiffness was mild in 158 of 525 (30%), intermediate in 194 (37%), severe in 97 (18%) and extreme in 19 (4%) patients. Patients with prolonged morning stiffness reported more pain, worse physical function and had a reduced mental and physical quality of life. Patients with prolonged morning stiffness also had more severe radiographic disease, although the association did not reach statistical significance. CONCLUSIONS: Prolonged and severe morning stiffness are frequently present in patients with hand OA. Patients with these symptoms report more pain in general and have a lower quality of life than patients that do not report these symptoms. Prolonged morning stiffness does not preclude a diagnosis of hand OA.

Test-retest precision and longitudinal cartilage thickness loss in the IMI-APPROACH cohort.

OBJECTIVE: To investigate the test-retest precision and to report the longitudinal change in cartilage thickness, the percentage of knees with progression and the predictive value of the machine-learning-estimated structural progression score (s-score) for cartilage thickness loss in the IMI-APPROACH cohort - an exploratory, 5-center, 2-year prospective follow-up cohort. DESIGN: Quantitative cartilage morphology at baseline and at least one follow-up visit was available for 270 of the 297 IMI-APPROACH participants (78% females, age: 66.4 ± 7.1 years, body mass index (BMI): 28.1 ± 5.3 kg/m2, 55% with radiographic knee osteoarthritis (OA)) from 1.5T or 3T MRI. Test-retest precision (root mean square coefficient of variation) was assessed from 34 participants. To define progressor knees, smallest detectable change (SDC) thresholds were computed from 11 participants with longitudinal test-retest scans. Binary logistic regression was used to evaluate the odds of progression in femorotibial cartilage thickness (threshold: -211 µm) for the quartile with the highest vs the quartile with the lowest s-scores. RESULTS: The test-retest precision was 69 µm for the entire femorotibial joint. Over 24 months, mean cartilage thickness loss in the entire femorotibial joint reached -174 µm (95% CI: [-207, -141] µm, 32.7% with progression). The s-score was not associated with 24-month progression rates by MRI (OR: 1.30, 95% CI: [0.52, 3.28]). CONCLUSION: IMI-APPROACH successfully enrolled participants with substantial cartilage thickness loss, although the machine-learning-estimated s-score was not observed to be predictive of cartilage thickness loss. IMI-APPROACH data will be used in subsequent analyses to evaluate the impact of clinical, imaging, biomechanical and biochemical biomarkers on cartilage thickness loss and to refine the machine-learning-based s-score. GOV IDENTIFICATION: NCT03883568.

Subluxation of the first carpometacarpal joint and age are important factors in reduced hand strength in patients with hand osteoarthritis.

OBJECTIVE: To investigate the determinants of hand strength in patients with hand osteoarthritis (OA). METHOD: Pinch and cylinder grip strength were measured in 527 patients with hand OA diagnosed by their treating rheumatologist from the Hand OSTeoArthritis in Secondary care (HOSTAS) study. Radiographs of hands (22 joints) were scored 0-3 (scaphotrapeziotrapezoid and first interphalangeal joints 0-1) on osteophytes and joint space narrowing following the Osteoarthritis Research Society International atlas. The first carpometacarpal joint (CMC1) was scored 0-1 for subluxation. Pain was assessed with the Australian/Canadian Hand Osteoarthritis Index pain subscale, and health-related quality of life with the Short Form-36. Regression analysis served to investigate associations of hand strength with patient, disease, and radiographic features. RESULTS: Hand strength was negatively associated with female sex, age, and pain. Reduced hand strength was associated with reduced quality of life, although less after adjusting for pain. Radiographic features of hand OA were associated with reduced grip strength when solely adjusted for sex and body mass index, but only CMC1 subluxation in the dominant hand remained significantly associated with pinch grip adjusted additionally for age (-0.511 kg, 95% confidence interval -0.975; -0.046). Mediation analysis showed low and not significant percentages of mediation of hand OA in the association between age and grip strength. CONCLUSIONS: Subluxation of CMC1 is associated with reduced grip strength, whereas associations with other radiographic features seem to be confounded by age. In the relationship between age and hand strength, radiographic hand OA severity is not an important mediator.

The association of clinical and structural knee osteoarthritis with physical activity in the middle-aged population: the NEO study.

OBJECTIVE: To investigate if knee osteoarthritis (OA) is associated with lower physical activity in the general middle-aged Dutch population, and if physical activity is associated with patient-reported outcomes in knee OA. DESIGN: Clinical knee OA was defined in the Netherlands Epidemiology of Obesity population using the ACR criteria, and structural knee OA on MRI. We assessed knee pain and function with the Knee Injury and Osteoarthritis Score (KOOS), health-related quality of life (HRQoL) with the Short Form-36, and physical activity (in Metabolic Equivalent of Task (MET) hours) with the Short Questionnaire to Assess Health-enhancing physical activity. We analysed the associations of knee OA with physical activity, and of physical activity with knee pain, function, and HRQoL in knee OA with linear regression adjusted for potential confounders. RESULTS: Clinical knee OA was present in 14% of 6,212 participants, (mean age 56 years, mean BMI 27 kg/m2, 55% women, 24% having any comorbidity) and structural knee OA in 12%. Clinical knee OA was associated with 9.60 (95% CI 3.70; 15.50) MET hours per week more physical activity, vs no clinical knee OA. Structural knee OA was associated with 3.97 (-7.82; 15.76) MET hours per week more physical activity, vs no structural knee OA. In clinical knee OA, physical activity was not associated with knee pain, function or HRQoL. CONCLUSIONS: Knee OA was not associated with lower physical activity, and in knee OA physical activity was not associated with patient-reported outcomes. Future research should indicate the optimal treatment advice regarding physical activity for individual knee OA patients.

Avidity maturation of anti-citrullinated protein antibodies in rheumatoid arthritis.

OBJECTIVE: Anti-citrullinated protein antibodies (ACPAs) are highly specific for rheumatoid arthritis (RA) and are present years before the onset of symptoms. The avidity of autoantibodies can have a strong impact on their effector potency. This study was undertaken to analyze the avidity of ACPAs in serum samples obtained from ACPA-positive healthy individuals (predisease), patients with early disease, and patients with established RA as well as the avidity maturation over time in samples from healthy subjects who later developed RA. METHODS: We measured ACPA avidity in serum samples from ACPA-positive healthy individuals, symptomatic individuals, and patients with established RA in 5 collections from The Netherlands, Canada, and Austria. We determined the dynamics of avidity maturation of ACPAs from the predisease stage to established disease in 1 case from the native North American population and in 10 cases from a Dutch blood donor cohort. RESULTS: The overall ACPA response was characterized by low-avidity antibodies. Higher-avidity ACPAs were observed in symptomatic patients only, while low-avidity ACPAs were observed in both healthy subjects and patients. In longitudinal samples obtained from subjects prior to disease onset, ACPA avidity increased over time until disease onset. No further avidity maturation was observed after disease onset. CONCLUSION: Our findings indicate that avidity maturation of the ACPA response takes place prior to disease onset.