Effects of Abatacept on T-Lymphocyte Sub-populations and Immunoglobulins in Patients Affected by Rheumatoid Arthritis.

BACKGROUND: Abatacept acts as a co-stimulation modulator preventing activation of T cells. Although it is approved for the treatment of rheumatoid arthritis (RA), its effects on adaptive immune response have not been fully elucidated. OBJECTIVES: To observe, in a cohort study, based on a clinical practice setting, the variation of peripheral blood T cells, immunoglobulin levels, and autoantibodies in the serum of RA patients during abatacept therapy. METHODS: Our study comprised 48 RA patients treated with abatacept. All clinical data were collected at baseline and after 3 months of treatment. Clinical and laboratory tests included erythrocyte sedimentation rate, C-reactive protein, 28-joint disease activity score, RF, anti-citrullinated protein antibody, total immunoglobulins, immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), and lymphocyte sub-population. RESULTS: Total immunoglobulin serum levels significantly decreased after 3 months of treatment and correlated positively with disease activity both at baseline and after 3 months of abatacept treatment. A reduction of serum IgM, IgG, IgA and RF was also demonstrated. The absolute number and percentage of cytotoxic (CD8+) T cells significantly decreased after 3 months of abatacept treatment, in particular the percentage of cytotoxic (CD8+) T cells significantly decreased only in patients responding to the treatment. CONCLUSIONS: Our results highlight a different role of abatacept in the modulation of the adaptive immune response in RA by the reduction of polyclonal B-cell activation and cytotoxic T cells.

Factors Predicting 2 Years of Remission and Low Disease Activity in Rheumatoid Arthritis Patients Treated with TNF-inhibitors.

BACKGROUND: The goals of treatment for rheumatoid arthritis (RA) are remission and low disease activity (LDA). However, many patients do not reach or maintain these targets with regard to disease control. OBJECTIVES: To identify predictive factors of remission/LDA in a cohort of RA patients who started treatment with first line tumor necrosis factor-inhibitors (TNF-i). METHODS: We included 308 RA patients treated with first line TNF-i for 2 years to evaluate remission/LDA based on the 28-joint disease activity score (DAS28). Predictive factors considered for achievement of remission/LDA were: gender, age at the time of TNF-i treatment, early arthritis, baseline C-reactive protein (CRP) and erythrocyte sedimentation rate levels, RF/anti-citrullinated protein antibody positivity, good/moderate European League Against Rheumatism response at 6 months, co-morbidities, and concomitant disease modifying antirheumatic drugs (DMARDs). Intention to treat, receiver operating characteristic curve, and univariate and multivariate analyses by logistic regression were performed. RESULTS: Positive predictors of remission/LDA in both the univariate and the multivariate analyses were: male gender, age at the time of TNF-i treatment ≤ 54 years, negative baseline CRP, and concomitant DMARDs. The presence of any co-morbidity resulted to be a negative predictor of remission/LDA in both the univariate and the multivariate analyses. CONCLUSIONS: Demographic and clinical features were identified as reliable predictors of both the achievement and the maintenance of treatment targets in a cohort of RA patients treated for 2 years with first line TNF-i.

Systemic Sclerosis: Exploring the Potential Interplay Between Thyroid Disorders and Pregnancy Outcome in an Italian Cohort.

BACKGROUND: Evidence has shown that pregnancy failure (PF) in women with systemic sclerosis (SSc) consists mainly of preterm delivery (PD) and intrauterine growth restriction (IUGR). Thyroid dysfunction (TD) and Hashimoto's thyroiditis (HT) represent a common feature of SSc. Since TD has been associated with PF, its presence in SSc women may potentially affect pregnancy outcome. OBJECTIVES: To analyze the interplay between TD and PF in a cohort of SSc women. METHODS: SSc women (n=77) and age-matched controls from the general obstetric population (n=50) were included. Clinical/biochemical/instrumental data exploring TD and the visceral involvement were collected in the context of a clinical practice setting. Pregnancy outcome was assessed by registering the history of primary infertility, recurrent spontaneous abortion, PD (≤ 37 gestational week), IUGR, and intrauterine fetal death. RESULTS: A higher prevalence of PD/IUGR was recorded in the SSc cohort than the controls (P = 0.04). SSc women with PF showed a higher prevalence of diffuse SSc than women without PF (P = 0.03). Scl-70 positive SSc women had a higher prevalence of PF than women with anti-centromere positivity (P = 0.01). A higher prevalence of HT was recorded in SSc women with PF than in patients without (P = 0.04). CONCLUSIONS: Our findings support the evidence that women with SSc can have successful pregnancies despite a higher prevalence of PD/IUGR. Diffuse SSc and Scl-70 positivity may predispose SSc women to PF. Routine thyroid workup may be included in the multi-specialist monitoring of SSc women for the early detection of thyroid dysfunctions.

Small-Medium Vessel Vasculitides: is the Complement System a Potential Forgotten Target?

Systemic vasculitides are a group of uncommon diseases characterized by blood vessel inflammation. The complement system is involved in the pathogenesis and clinical manifestations of several autoimmune diseases, including systemic vasculitides. This enzymatic system is a component of the innate immune system. Its main function was initially believed to be limited to the recognition and elimination of pathogens, but research in recent years has demonstrated the important role that complement proteins play in modulating adaptive immunity and in bridging innate and adaptive responses. Its activation is also critical for the development of T cell immunity and natural antibodies as well as for the regulation of autoreactive B cells. In systemic vasculitides, particularly small-medium vesselvasculitides, the complement system has been shown to contribute to the development of inflammatory damage. In view of these crucial functions, the complement system represents an attractive therapeutic target for a wide range of diseases. including vasculitic disorders.

Anti-LL37 Antibodies Are Present in Psoriatic Arthritis (PsA) Patients: New Biomarkers in PsA.

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis. A third of psoriatic patients develop PsA via unknown mechanisms. No reliable diagnostic markers are available for PsA, or prognostic biomarkers for PsA development in psoriasis. We previously uncovered a pro-inflammatory role for cathelicidin LL37 in lesional psoriasis skin. LL37 binds nucleic acids and stimulates plasmacytoid/myeloid dendritic cells (pDC, mDCs) to secrete type I interferon (IFN-I) and pro-inflammatory factors. LL37 becomes an autoantigen for psoriatic Th1-Th17/CD8 T cells. Anti-LL37 antibodies were detected in systemic lupus erythematosus, an autoimmune disease characterized by neutrophil-extracellular-traps release (NETosis) in target organs. LL37 can be substrate of irreversible post-translational modifications, citrullination or carbamylation, linked to neutrophil activity. Here we analyzed inflammatory factors, included LL37, in PsA and psoriasis plasma and PsA synovial fluids (SF)/biopsies. We show that LL37 (as a product of infiltrating neutrophils) and autoantibodies to LL37 are elevated in PsA, but not OA SF. Anti-LL37 antibodies correlate with clinical inflammatory markers. Anti-carbamylated/citrullinated-LL37 antibodies are present in PsA SF/plasma and, at lower extent, in psoriasis plasma, but not in controls. Plasma anti-carbamylated-LL37 antibodies correlate with PsA (DAS44) but not psoriasis (PASI) disease activity. Ectopic lymphoid structures, and deposition of immunoglobulin-(Ig)G-complexes (IC) co-localizing with infiltrating neutrophils, are observed in PsA and not OA synovial tissues (ST). Activated complement (C5a, C9), GM-CSF and IFN-I are up-regulated in PsA and not OA synovia and in PsA and psoriasis plasma but not in HD. C9 and GM-CSF levels in PsA SF correlate with clinical inflammatory markers and DAS44 (C9) and with anti-carbamylated/citrullinated-LL37 antibodies (GM-CSF and IFN-I). Thus, we uncover a role for LL37 as a novel PsA autoantibody target and correlation studies suggest participation of anti-LL37 antibodies to PsA pathogenesis. Notably, plasma antibodies to carbamylated-LL37, which correlate with DAS44, suggest their use as new disease activity markers. GM-CSF and complement C5a and C9 elevation may be responsible for autoantigens release by neutrophils and their modification, fueling inflammation and autoreactivity establishment. Finally, targeting GM-CSF, C5a, C9 can be beneficial in PsA.