Ultrasound assessment as predictor of disease relapse in children and adults with arthritis in clinical stable remission: new findings but still unmet needs

Clinical and associated inflammatory biomarker features predictive of short-term outcomes in non-systemic juvenile idiopathic arthritis

OBJECTIVE

To identify early predictors of disease activity at 18 months in JIA using clinical and biomarker profiling.

METHODS

Clinical and biomarker data were collected at JIA diagnosis in a prospective longitudinal inception cohort of 82 children with non-systemic JIA, and their ability to predict an active joint count of 0, a physician global assessment of disease activity of ≤1 cm, and inactive disease by Wallace 2004 criteria 18 months later was assessed. Correlation-based feature selection and ReliefF were used to shortlist predictors and random forest models were trained to predict outcomes.

RESULTS

From the original 112 features, 13 effectively predicted 18-month outcomes. They included age, number of active/effused joints, wrist, ankle and/or knee involvement, ESR, ANA positivity and plasma levels of five inflammatory biomarkers (IL-10, IL-17, IL-12p70, soluble low-density lipoprotein receptor-related protein 1 and vitamin D), at enrolment. The clinical plus biomarker panel predicted active joint count = 0, physician global assessment ≤ 1, and inactive disease after 18 months with 0.79, 0.80 and 0.83 accuracy and 0.84, 0.83, 0.88 area under the curve, respectively. Using clinical features alone resulted in 0.75, 0.72 and 0.80 accuracy, and area under the curve values of 0.81, 0.78 and 0.83, respectively.

CONCLUSION

A panel of five plasma biomarkers combined with clinical features at the time of diagnosis more accurately predicted short-term disease activity in JIA than clinical characteristics alone. If validated in external cohorts, such a panel may guide more rationally conceived, biologically based, personalized treatment strategies in early JIA.

Distinct synovial tissue macrophage subsets regulate inflammation and remission in rheumatoid arthritis

Immune-regulatory mechanisms of drug-free remission in rheumatoid arthritis (RA) are unknown. We hypothesized that synovial tissue macrophages (STM), which persist in remission, contribute to joint homeostasis. We used single-cell transcriptomics to profile 32,000 STMs and identified phenotypic changes in patients with early/active RA, treatment-refractory/active RA and RA in sustained remission. Each clinical state was characterized by different frequencies of nine discrete phenotypic clusters within four distinct STM subpopulations with diverse homeostatic, regulatory and inflammatory functions. This cellular atlas, combined with deep-phenotypic, spatial and functional analyses of synovial biopsy fluorescent activated cell sorted STMs, revealed two STM subpopulations (MerTKposTREM2high and MerTKposLYVE1pos) with unique remission transcriptomic signatures enriched in negative regulators of inflammation. These STMs were potent producers of inflammation-resolving lipid mediators and induced the repair response of synovial fibroblasts in vitro. A low proportion of MerTKpos STMs in remission was associated with increased risk of disease flare after treatment cessation. Therapeutic modulation of MerTKpos STM subpopulations could therefore be a potential treatment strategy for RA.

Juvenile Idiopathic Arthritis for the Pediatric Orthopedic Surgeon

Juvenile idiopathic arthritis includes conditions characterized by joint inflammation of unknown etiology lasting longer than 6 weeks in patients younger than 16 years. Diagnosis and medical management are complex and best coordinated by a pediatric rheumatologist. The mainstay of therapy is anti-inflammatory and biologic medications to control pain and joint inflammation. Orthopedic surgical treatment may be indicated for deformity, limb length inequality, or end-stage arthritis. Evaluation of the cervical spine and appropriate medication management in consultation with a patient's rheumatologist are essential in perioperative care. Preoperative planning should take into account patient deformity, contracture, small size, osteopenia, and medical comorbidities.

Ultrasound detected changes in joint cartilage thickness in juvenile idiopathic arthritis

AIM

The purpose of this study was to investigate the changes in joint cartilage thickness in different subtypes of juvenile idiopathic arthritis (JIA) using ultrasound, comparing them with healthy children and to evaluate the relationship with disease duration and inflammatory markers.

METHODS

We conducted a cross-sectional study comprising of 27 cases of JIA and 54 age- and sex-matched healthy children. Bilateral wrist, knee and ankle joint cartilage thicknesses were measured by ultrasound as per European League Against Rheumatism standard guidelines and compared them between JIA subtypes as well as between cases and control.

RESULTS

Descriptive analysis of the whole cohort revealed the mean age of the study population was 8.3 ± 3.2 years with mean cartilage thicknesses at the wrist, knee and ankle being 1.40 ± 0.89 mm, 1.57 ± 0.78 mm and 1.41 ± 0.85 mm, respectively. The median cartilage thicknesses of wrist, knee and ankle joints of JIA cases (n = 27) and healthy controls (n = 54) were 1.01, 1.35, 1.05 and 1.95, 2.00, 1.95, respectively. The joint cartilage thickness was significantly reduced in JIA in comparison to the healthy cohort (P < 0.01). Diseased boys suffered greater cartilage damage in knee joints compared to girls; the polyarticular variety of cases had thinner knee cartilage in comparison to the oligoarticular subtype. Further, it was found that joint cartilage destruction is independent of inflammatory markers and disease duration.

CONCLUSION

Significant cartilage thinning in addition was found in JIA children, particularly in the polyarticular subtype, and more in boys than girls, which is independent of disease duration and inflammatory markers, using ultrasound as a primary investigative tool.