Memory B cell subsets and plasmablasts are lower in early than in long-standing Rheumatoid Arthritis

Alterations of B cell subset distribution have been described in the peripheral blood (PB) of rheumatoid arthritis (RA) patients, but no data are available on differences between the onset and the established phases of the disease. The purpose of the study was to clarify whether a peculiar distribution of B cell subsets characterizes RA onset, thus leading to a more favorable clinical response to treatment, and to evaluate the possible association of a particular B cell subpopulation with response to therapy

MicroRNA-155 influences B-cell function through PU.1 in rheumatoid arthritis

MicroRNA-155 (miR-155) is an important regulator of B cells in mice. B cells have a critical role in the pathogenesis of rheumatoid arthritis (RA). Here we show that miR-155 is highly expressed in peripheral blood B cells from RA patients compared with healthy individuals, particularly in the IgD-CD27- memory B-cell population in ACPA+ RA. MiR-155 is highly expressed in RA B cells from patients with synovial tissue containing ectopic germinal centres compared with diffuse synovial tissue. MiR-155 expression is associated reciprocally with lower expression of PU.1 at B-cell level in the synovial compartment. Stimulation of healthy donor B cells with CD40L, anti-IgM, IL-21, CpG, IFN-α, IL-6 or BAFF induces miR-155 and decreases PU.1 expression. Finally, inhibition of endogenous miR-155 in B cells of RA patients restores PU.1 and reduces production of antibodies. Our data suggest that miR-155 is an important regulator of B-cell activation in RA

The bnt162b2 vaccine induces humoral and cellular immune memory to sars-cov-2 Wuhan strain and the Omicron variant in children 5 to 11 years of age

SARS-CoV-2 mRNA vaccines prevent severe COVID-19 by generating immune memory, comprising specific antibodies and memory B and T cells. Although children are at low risk of severe COVID-19, the spreading of highly transmissible variants has led to increasing in COVID-19 cases and hospitalizations also in the youngest, but vaccine coverage remains low. Immunogenicity to mRNA vaccines has not been extensively studied in children 5 to 11 years old. In particular, cellular immunity to the wild-type strain (Wuhan) and the cross-reactive response to the Omicron variant of concern has not been investigated. We assessed the humoral and cellular immune response to the SARS-CoV-2 BNT162b2 vaccine in 27 healthy children. We demonstrated that vaccination induced a potent humoral and cellular immune response in all vaccinees. By using spike-specific memory B cells as a measurable imprint of a previous infection, we found that 50% of the children had signs of a past, undiagnosed infection before vaccination. Children with pre-existent immune memory generated significantly increased levels of specific antibodies, and memory T and B cells, directed against not only the wild type virus but also the omicron variant

Safety of Abatacept in Italian Patients with Rheumatoid Arthritis and Interstitial Lung Disease: A Multicenter Retrospective Study

Treatment of rheumatoid arthritis (RA)-related interstitial lung disease (ILD) is challenging, and many conventional and biologic disease-modifying anti-rheumatic drugs (DMARDs) have been associated with ILD development or progression. The aim of this multicentric retrospective study was to analyze the evolution of ILD in Italian RA-ILD patients treated with abatacept (ABA)

Overweight/obesity affects histological features and inflammatory gene signature of synovial membrane of Rheumatoid Arthritis

Overweight/obesity influence disease burden and clinical outcome of Rheumatoid Arthritis (RA). The impact of overweight/obesity on synovial tissue (ST) inflammation is largely unknown. Here, we investigated the histological and transcriptional signature of ST obtained from RA in different disease phases (disease onset, failure to first-line conventional DMARDs and in sustained clinical and ultrasound remission) finding that overweight/obese DMARDs naive RA showed higher likelihood of follicular synovitis, higher IHC scores for sublining inflammatory cells (CD68+, CD21+ and CD20+) and higher IL-1RA plasma levels than normal weight RA. Regardless to the synovitis pattern, overweight/obese DMARDs naive RA showed a worse clinical response to "Treat-to-target" (T2T) than normal weight RA at 6 and 12 months follow-up. Conversely, MTX-IR RA did not show significant differences in synovial inflammation based on BMI category. Overweight/obese RA in stable clinical and US remission showed higher degree of residual synovitis in terms of sublining CD68+, CD20+ cells and lining and sublining CD3+ compared to normal weight RA. Finally, gene expression profile analysis revealed that ST of overweight/obese DMARDs naive RA is enriched by CCL3 and MyD88 compared to normal weight RA in sustained disease remission, the latter correlating with BMI and IHC scores for synovial CD68+ cells. These findings suggest that indeed overweight/obese RA show higher degree of synovitis at disease onset and after remission achievement that influences the response rate to T2T and should be considered within the management of patients with RA

Synovial features of patients with rheumatoid arthritis and psoriatic arthritis in clinical and ultrasound remission differ under anti-TNF therapy: A clue to interpret different chances of relapse after clinical remission?

Objective To define the synovial characteristics of patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA) in clinical and ultrasound remission achieved by combination therapy with methotrexate (MTX) and tumour necrosis factor (TNF) blockers. Methods Patients with RA in remission (n=25) (disease activity score (DAS)<1.6 for at least 6 months), patients with RA in low disease activity (LDA) (n=10) (1.6<2.4 for at least 6 months) and patients with PsA in remission (n=18) (DAS<1.6 and Psoriasis Area Severity Index (PASI)=0 for at least 6 months) achieved by MTX+anti-TNF (adalimumab 40 mg or etanercept 50 mg) with power Doppler (PDUS)-negative synovial hypertrophy underwent synovial tissue biopsy. Patients with RA with high/moderate disease na\uefve to treatment (n=50) were included as a comparison group. Immunostaining for cluster designation (CD)68, CD21, CD20, CD3, CD31 and collagen was performed. Results PDUS-negative patients with RA in remission showed lower histological scores for synovial CD68+, CD20+, CD3+ cells and CD31+ vessels and collagen deposition (p<0.05 for both lining and sublining) compared with PDUS-positive patients with RA with high/moderate disease. In addition, there was no significant difference in terms of lining and sublining CD68+, CD20+, CD3+, CD31+ cells and collagen comparing PDUS-negative patients with RA in remission and in LDA, respectively. On the contrary, PDUS-negative patients with PsA in remission showed higher histological scores for sublining CD68+ (p=0.02) and CD3+ cells (p=0.04) as well as CD31+ vessels (p<0.001) than PDUS-negative patients with RA in remission. Conclusions PDUS-negative patients with RA in remission have comparable synovial histological features than PDUS-negative patients with RA in LDA. However, patients with PsA in remission are characterised by a higher degree of residual synovial inflammation than patients with RA in remission, despite PDUS negativity under TNF inhibition

Chemerin and PEDF are metaflammation-related biomarkers of disease activity and obesity in rheumatoid arthritis

Objective: Obesity is a risk factor for Rheumatoid Arthritis (RA) being associated to low grade inflammation. This study aimed to determine whether PEDF and Chemerin are biomarkers of inflammation related to fat accumulation in RA and to investigate whether weight loss associates with clinical disease improvement through the modification of fat-related biomarkers in overweight/obese RA with low-moderate disease. Participants and Methods: Two-hundred and thirty RA patients were enrolled, of whom 176 at disease onset treated according to a treat-to-target strategy (T2T) and 54 overweight/obese RA in stable therapy and low-moderate disease activity. Gene expression of adipokines, interleukin-6 and their receptors were examined in adipose tissue from obese RA. Obese RA with low-moderate disease activity underwent low-calories diet aiming to Body Mass Index (BMI) reduction > 5%, maintaining RA therapy unchanged. Chemerin, PEDF and Interleukin-6 plasma values were assessed by ELISA and disease activity was evaluated. Results: At RA onset, PEDF and Chemerin plasma values correlated with BMI (p < 0.001) but only Chemerin plasma values correlated with disease activity (p < 0.001). After adopting a T2T strategy, Chemerin arose as an independent factor associated with remission in early RA [OR(95%CIs):0.49(0.25-0.97)]. Moreover, after low-calories diet, RA with low-moderate disease activity reaching BMI reduction 655% (62.6%) at 6 months had significant decrease of PEDF (p < 0.05) and Chemerin (p < 0.05) plasma values, in parallel with the improvement in disease activity. Conclusions: PEDF and Chemerin arose as biomarkers of obesity and metaflammation respectively, providing a link between chronic inflammation and excess of body weight in RA. Therefore, BMI reduction of at least 5% in obese RA allowed better disease control without modifying RA treatment

Porphyromonas gingivalis and the pathogenesis of rheumatoid arthritis: analysis of various compartments including the synovial tissue

Introduction: We evaluated the presence of Porphyromonas gingivalis (Pg) DNA in the synovial tissue through synovial biopsy and in other compartments of RA patients in comparison with patients affected by other arthritides. Possible links with clinical, immunologic and genetic features were assessed. Methods: Peripheral blood (PB), sub-gingival dental plaque, synovial fluid (SF) and synovial tissue samples were collected from 69 patients with active knee arthritis (32 with RA and 37 with other arthritides, of which 14 with undifferentiated peripheral inflammatory arthritis - UPIA). Demographic, clinical, laboratory and immunological data were recorded. The presence of Pg DNA was evaluated through PCR. The HLA-DR haplotype was assessed for 45 patients with RA and UPIA. Results: No differences arose in the positivity for Pg DNA in the sub-gingival plaque, PB and SF samples between RA and the cohort of other arthritides. Full PB samples showed a higher positivity for Pg DNA than plasma samples (11.8% vs. 1.5%, p=0.04). Patients with RA showed a higher positivity for Pg DNA in the synovial tissue compared to controls (33.3% vs. 5.9%, p<0.01). UPIA and RA patients carrying the HLA DRB1*04 allele showed a higher positivity for Pg DNA in the synovial tissue compared to patients negative for the allele (57.1% vs. 16.7%, p=0.04). RA patients positive for Pg DNA in the sub-gingival plaque had a lower disease duration and a higher peripheral blood leucocytes and neutrophils count. The presence of Pg DNA did not influence disease activity, disease disability or positivity for autoantibodies. Conclusions: The presence of Pg DNA in the synovial tissue of RA patients suggests a pathogenic role of the bacterium. The higher positivity of Pg DNA in full peripheral blood and synovial tissue samples compared to plasma and synovial fluid suggests a possible intracellular localization of Pg, in particular in patients positive for HLA-DR4

Synovial predictors of differentiation to definite arthritis in patients with seronegative undifferentiated peripheral inflammatory arthritis: MicroRNA signature, histological, and ultrasound features

Objectives: To examine synovial tissue (ST) predictors of clinical differentiation in patients with seronegative undifferentiated peripheral inflammatory arthritis (UPIA). Methods: Fourty-two patients with IgA/IgM-Rheumatoid Factor and anti-citrullinated peptide antibodies negative UPIA, naive to Disease-Modifying Anti-Rheumatic Drugs, underwent Gray Scale (GSUS) and power Doppler (PDUS) evaluation and Ultrasound (US) guided ST biopsy. CD68, CD 3 , CD 21 , CD 20 , and CD 31 synovial expression was evaluated by immunohistochemistry. Whole ST microRNA expression was assessed using miScript miRNA PCR Array. Peripheral blood (PB) and synovial fluid (SF) IL-6, VEGF-A, and VEGF-D levels were measured by ELISA and ST TNF expression was assessed by RT-PCR. Each patient was prospectively monitored and classified at baseline and within 1 year as UPIA, Rheumatoid Arthritis (RA), Spondyloarthritis (SpA) or Psoriatic Arthritis (PsA), respectively. Results: At baseline, CD68 + cells were the most common cells within the lining layer (p &lt; 0.001) in seronegative UPIA, directly correlating with GSUS (R = 0.36; p = 0.02) and PDUS (R = 0.55; p &lt; 0.001). Synovial CD 31+ vessels count directly correlated with GSUS (R = 0.41; p = 0.01) and PDUS (R = 0.52; p &lt; 0.001). During the follow-up, 6 (14.3%) UPIA reached a definite diagnosis (2 RA, 2 SpA and 2 PsA, respectively). At baseline, UPIA who differentiated had higher GSUS (p = 0.01), PDUS scores (p = 0.02) and higher histological scores for CD68+ (p = 0.005 and p = 0.04 for lining and sublining respectively), sublining CD 3+ cells (p = 0.002), CD 31+ vessels count (p &lt; 0.001) and higher IL-6 PB levels (p = 0.01) than patients who remained as UPIA. MiRNA PCR Array showed that among the 86 tested miRNA species, at baseline, miR-346 and miR-214 were significantly down-regulated (p = 0.02 for both) in ST of UPIA who differentiated than in patients who remained as UPIA, inversely correlating with the lining CD68+ cells IHC score (R = -0.641; p = 0.048) and CD 31+ vessels count (R = -0.665; p = 0.036) and with higher baseline ST expression of TNF (p = 0.014). Finally, logistic regression analysis demonstrated that baseline GSUS and PDUS scores 651.5 [OR:22.93 (95%CI:0.98-534.30)] and CD 31+ vessels count 6524.3 [OR:23.66 (95%CI:1.50-373.02)] were independent factors associated with the development of definite arthritis. Conclusions: MiRNA signature, histological and US features of ST may help in the identification of seronegative UPIA with high likelihood of clinical differentiation toward definite seronegative arthritis