Correlation of Professional Antigen-Presenting Tbet+CD11c+ B Cells With Bone Destruction in Untreated Rheumatoid Arthritis.

OBJECTIVE: Subsets of CD21-/low memory B cells (MBCs), including double-negative (DN, CD27-IgD-) and Tbet+CD11c+ cells, are expanded in chronic inflammatory diseases. In rheumatoid arthritis (RA), CD21-/low MBCs correlate with joint destruction. However, whether this is due to the Tbet+CD11c+ subset, its function and pathogenic contribution to RA are unknown. This study aims to investigate the association between CD21-/lowTbet+CD11c+ MBCs and joint destruction as well as other clinical parameters and to elucidate their functional properties in patients with untreated RA (uRA). METHODS: Clinical observations were combined with flow cytometry (n = 36) and single-cell RNA sequencing (scRNA-seq) and V(D)J sequencing (n = 4) of peripheral blood (PB) MBCs from patients with uRA. The transcriptome of circulating Tbet+CD11c+ MBCs was compared with scRNA-seq data of synovial B cells. In vitro coculture of Tbet+CD11c+ B cells with T cells was used to assess costimulatory capacity. RESULTS: CD21-/lowTbet+CD11c+ MBCs in PB correlated with bone destruction but no other clinical parameters analyzed. The Tbet+CD11c+ MBCs have undergone clonal expansion and express somatically mutated V genes. Gene expression analysis of these cells identified a unique signature of more than 150 up-regulated genes associated with antigen presentation functions, including B cell receptor activation and clathrin-mediated antigen internalization; regulation of actin filaments, endosomes, and lysosomes; antigen processing, loading, presentation, and costimulation; a transcriptome mirrored in their synovial tissue counterparts. In vitro, Tbet+CD11c+ B cells induced retinoic acid receptor-related orphan nuclear receptor γT expression in CD4+ T cells, thereby polarizing to Th17 cells, a T cell subset critical for osteoclastogenesis and associated with bone destruction. CONCLUSION: This study suggests that Tbet+CD11c+ MBCs contribute to the pathogenesis of RA by promoting bone destruction through antigen presentation, T cell activation, and Th17 polarization.

Pathogenic antibody response to glucose-6-phosphate isomerase targets a modified epitope uniquely exposed on joint cartilage.

OBJECTIVES: To identify the arthritogenic B cell epitopes of glucose-6-phosphate isomerase (GPI) and their association with rheumatoid arthritis (RA). METHODS: IgG response towards a library of GPI peptides in patients with early RA, pre-symptomatic individuals and population controls, as well as in mice, were tested by bead-based multiplex immunoassays and ELISA. Monoclonal IgG were generated, and the binding specificity and affinity were determined by ELISA, gel size exclusion chromatography, surface plasma resonance and X-ray crystallography. Arthritogenicity was investigated by passive transfer experiments. Antigen-specific B cells were identified by peptide tetramer staining. RESULTS: Peptide GPI293-307 was the dominant B cell epitope in K/BxN and GPI-immunised mice. We could detect B cells and low levels of IgM antibodies binding the GPI293-307 epitopes, and high affinity anti-GPI293-307 IgG antibodies already 7 days after GPI immunisation, immediately before arthritis onset. Transfer of anti-GPI293-307 IgG antibodies induced arthritis in mice. Moreover, anti-GPI293-307 IgG antibodies were more frequent in individuals prior to RA onset (19%) than in controls (7.5%). GPI293-307-specific antibodies were associated with radiographic joint damage. Crystal structures of the Fab-peptide complex revealed that this epitope is not exposed in native GPI but requires conformational change of the protein in inflamed joint for effective recognition by anti-GPI293-307 antibodies. CONCLUSIONS: We have identified the major pathogenic B cell epitope of the RA-associated autoantigen GPI, at position 293-307, exposed only on structurally modified GPI on the cartilage surface. B cells to this neo-epitope escape tolerance and could potentially play a role in the pathogenesis of RA.

Autoantibodies to Disease-Related Proteins in Joints as Novel Biomarkers for the Diagnosis of Rheumatoid Arthritis.

OBJECTIVE: This study was undertaken to develop and characterize a multiplex immunoassay for detection of autoantibodies against peptides derived from proteins known to play a role in development of arthritis and that are also expressed in joints. METHODS: We selected peptides from the human counterpart of proteins expressed in the joints, based on mouse models that showed these to be targeted by pathogenic or regulatory antibodies in vivo. Using bead-based flow immunoassays measuring IgG antibodies, we selected triple helical or cyclic peptides, containing the epitopes, to avoid collinear reactivity. We characterized the analytical performance of the immunoassay and then validated it in 3 independent rheumatoid arthritis (RA) cohorts (n = 2,110), Swedish age- and sex-matched healthy controls, and patients with osteoarthritis (OA), patients with psoriatic arthritis (PsA), and patients with systemic lupus erythematosus (SLE). RESULTS: Screening assays showed 5 peptide antigens that discriminated RA patients from healthy controls with 99% specificity (95% confidence interval [CI] 98-100%). In our validation studies, we reproduced the discriminatory capacity of the autoantibodies in 2 other RA cohorts, showing that the autoantibodies had high discriminatory capacity for RA versus OA, PsA, and SLE. The novel biomarkers identified 22.5% (95% CI 19-26%) of early RA patients seronegative for anti-cyclic citrullinated peptide and rheumatoid factor. The usefulness of the biomarkers in identifying seronegative RA patients was confirmed in validation studies using 2 independent cohorts of RA patients and cohorts of patients with OA, PsA, and SLE. CONCLUSION: A multiplex immunoassay with peptides from disease-related proteins in joints was found to be useful for detection of specific autoantibodies in RA serum. Of note, this immunoassay had high discriminatory capacity for early seronegative RA.

Misdiagnosis of Rheumatoid Arthritis in a Long-Term Cohort of Early Arthritis Based on the ACR-1987 Classification Criteria.

Objective: Correct diagnosis of early rheumatoid arthritis (RA) is essential for optimal treatment choices. No pathognomonic test is available, and diagnosis is based on classification criteria, which can result in misdiagnosis. Here, we examined the differences between actual and misdiagnosed RA cases in a long-term cohort of patients included based on the ACR-1987 classification criteria. Methods: Patients in the BARFOT (Better Anti-Rheumatic PharmacOTherapy) cohort (n=2543) with at least four follow-up visits during the initial 5 years from enrolment were assessed, and a change in diagnosis was reported by the treating rheumatologist. The groups were analysed with respect to the individual classification criteria, antibodies to citrullinated proteins (ACPA), disease activity (DAS28) and radiographic changes from inclusion up to 2 years. Results: Forty-five patients (1.8%) were misdiagnosed (RA-change group). When compared to those in the RA-change group, the patients who kept their diagnosis (RA-keep) were more often RF positive (64% vs 21%, p<0.001) or ACPA positive (59% vs 8%, p<0.001). They were also more likely to fulfil more than four ACR-1987 criteria (64% vs 33%, p<0.001) and to have radiographic changes at inclusion (RA-keep 27% vs RA-change 12%, p=0.04). The groups had a similar evolution of DAS28 and its components as well as of radiological joint destruction. Conclusion: Diagnosis of RA according to the ACR-1987 criteria had a high precision in this long-term cohort. A diagnosis of RA should be re-evaluated in patients who do not fulfil more than four ACR-1987 criteria especially in patients negative for RF.

Influence of Age and Sex on Disease Course and Treatment in Rheumatoid Arthritis.

OBJECTIVE: More than 50% of patients with rheumatoid arthritis (RA) are >65 years at diagnosis. Age of onset and sex may influence the disease course, outcome and treatment. This study follows a large cohort of patients with early RA to assess contributions of age and sex to disease outcomes. METHODS: Patients from the BARFOT cohort, n=2837 (68% women), were followed for eight years at predefined time points to assess inflammation, function, joint destruction and treatment with disease modifying anti-rheumatic drugs (DMARDs) and glucocorticoids (GC). The patients were divided by sex and age at inclusion (<40, 40-54, 55-69 and ≥70 years). RESULTS: For both sexes, disease activity, function and pain improved over time, significantly more in men than in women in all age groups. In men, those <40 years displayed significantly lower DAS28 compared with all other groups. This group was also the least represented group in the study. The Sharp van der Heijde Score (SHS) increased over time in both sexes and all age groups. Women ≥70 years showed less improvement in disability and the highest progression of SHS mainly due to increased joint space narrowing. Patients <40 years were more likely to receive biological DMARDs, while those ≥70 years more often received only GC treatment. CONCLUSION: There were significant age- and sex-dependent differences in the medical treatment and in outcome of RA 8 years after diagnosis. The differences were most pronounced in men<40 and women ≥70 years, but whether they are due to disease phenotype or treatment is unclear.

Declining Well-Being in Young Swedes Born in 1990 Versus 1974.

PURPOSE: Well-being is affected by the environment, including societal changes. In this study, specific dimensions of well-being were compared in two cohorts of Swedish adolescents born 16 years apart. METHODS: Two groups of 18-year-olds, "Grow up Gothenburg" 1974 and 1990 birth cohorts, completed a self-reported questionnaire including the Gothenburg Well-Being in adolescence scale (GWBa). In addition, height and weight were measured, resulting in 4,362 participants (1974 birth cohort) and 5,151 participants (1990 birth cohort) with age, height, weight, and well-being data. The GWBa consists of a total score and five dimensions: mood, physical condition, energy, self-esteem, and stress balance. RESULTS: Total well-being was significantly lower in the later-born cohort, and the greatest difference was seen for the dimension stress balance (feeling calm, unconcerned, unstressed, and relaxed), although effect sizes were modest. In both boys and girls, well-being was lower for all dimensions in the later-born cohort, with the exception of Self-esteem in girls, which was higher in the later-born cohort. In both cohorts, boys reported higher well-being than girls for all dimensions. The mean body mass index z-score was higher in boys from the later-born cohort, but after adjusting for weight status, the differences in well-being between the cohorts persisted. CONCLUSIONS: Well-being was lower in the later-born cohort, particularly for the dimension stress balance. Differences were not explained by the shift in weight status indicating that other societal changes have had an impact on well-being levels. Managing high levels of stress might be an area of intervention in adolescents for improved well-being.

Effectiveness of a weight loss intervention in postpartum women: results from a randomized controlled trial in primary health care.

BACKGROUND: Reproduction has been identified as an important factor for long-term weight gain among women. A previous efficacy trial has successfully produced postpartum weight loss; however, the effectiveness of this intervention needs to be established. OBJECTIVE: This study was designed to evaluate the short- and long-term effectiveness of a diet behavior modification treatment to produce weight loss in postpartum women within the primary health care setting in Sweden. DESIGN: During 2011-2014, 110 women with a self-reported body mass index (BMI; in kg/m(2)) of ≥27 at 6-15 wk postpartum were randomly assigned to the diet behavior modification group (D group) or the control group (C group). Women randomly assigned to the D group (n = 54) received a structured 12-wk diet behavior modification treatment by a dietitian and were instructed to gradually implement a diet plan based on the Nordic Nutrition Recommendations and to self-weigh ≥3 times/wk. Women randomly assigned to the C group (n = 56) were given a brochure on healthy eating. The primary outcome was change in body weight after 12 wk and 1 y. The retention rate was 91% and 85% at 12 wk and 1 y, respectively. RESULTS: At baseline, women had a median (1st, 3rd quartile) BMI of 31.0 (28.8, 33.6), and 84% were breastfeeding. After 12 wk, median weight change in the D group was -6.1 kg (-8.4, -3.2 kg) compared with -1.6 kg (-3.5, -0.4 kg) in the C group (P < 0.001). The difference was maintained at the 1-y follow-up for the D group, -10.0 kg (-11.7, -5.9 kg) compared with -4.3 kg (-10.2, -1.0 kg) in the C group (P = 0.004). In addition, the D group reduced BMI, waist circumference, hip circumference, and body fat percentage more than did the C group at both 12 wk and 1 y (all P < 0.05). CONCLUSION: A low-intensity diet treatment delivered by a dietitian within the primary health care setting can produce clinically relevant and sustainable weight loss in postpartum women with overweight and obesity. This trial was registered at clinicaltrials.gov as NCT01949558.

Preeclampsia and Blood Pressure Trajectory during Pregnancy in Relation to Vitamin D Status.

Every tenth pregnancy is affected by hypertension, one of the most common complications and leading causes of maternal death worldwide. Hypertensive disorders in pregnancy include pregnancy-induced hypertension and preeclampsia. The pathophysiology of the development of hypertension in pregnancy is unknown, but studies suggest an association with vitamin D status, measured as 25-hydroxyvitamin D (25(OH)D). The aim of this study was to investigate the association between gestational 25(OH)D concentration and preeclampsia, pregnancy-induced hypertension and blood pressure trajectory. This cohort study included 2000 women. Blood was collected at the first (T1) and third (T3) trimester (mean gestational weeks 10.8 and 33.4). Blood pressure at gestational weeks 10, 25, 32 and 37 as well as symptoms of preeclampsia and pregnancy-induced hypertension were retrieved from medical records. Serum 25(OH)D concentrations (LC-MS/MS) in T1 was not significantly associated with preeclampsia. However, both 25(OH)D in T3 and change in 25(OH)D from T1 to T3 were significantly and negatively associated with preeclampsia. Women with a change in 25(OH)D concentration of ≥30 nmol/L had an odds ratio of 0.22 (p = 0.002) for preeclampsia. T1 25(OH)D was positively related to T1 systolic (ß = 0.03, p = 0.022) and T1 diastolic blood pressure (ß = 0.02, p = 0.016), and to systolic (ß = 0.02, p = 0.02) blood pressure trajectory during pregnancy, in adjusted analyses. There was no association between 25(OH)D and pregnancy-induced hypertension in adjusted analysis. In conclusion, an increase in 25(OH)D concentration during pregnancy of at least 30 nmol/L, regardless of vitamin D status in T1, was associated with a lower odds ratio for preeclampsia. Vitamin D status was significantly and positively associated with T1 blood pressure and gestational systolic blood pressure trajectory but not with pregnancy-induced hypertension.