Martina Fabris

Efficacy and safety of belimumab in primary Sjögren's syndrome: results of the BELISS open-label phase II study

BACKGROUND Increased expression of B cell activating factor (BAFF or B lymphocyte stimulator) may explain the B cell activation characteristic of primary Sjögrens syndrome (pSS). OBJECTIVES To evaluate the efficacy and safety of belimumab, targeting BAFF, in patients with pSS. METHODS Patients were included in this bi-centric prospective 1-year open-label trial if they fulfilled American European Consensus group criteria, were anti-Sjögrens syndrome A-positive and had current systemic complications or salivary gland enlargement, or early disease (<5 years), or biomarkers of B cell activation. They received belimumab, 10 mg/kg, at weeks 0, 2 and 4 and then every 4 weeks to week 24. The primary end-point, assessed at week 28, was improvement in two of five items: reduction in ≥30% in dryness score on a visual analogue scale (VAS), ≥30% in fatigue VAS score, ≥30% in VAS pain score, ≥30% in systemic activity VAS assessed by the physician and/or >25% improvement in any B cell activation biomarker values. RESULTS Among 30 patients included, the primary end-point was achieved in 18 (60%). The mean (SD) European League Against Rheumatism (EULAR) Sjögrens Syndrome Disease Activity Index decreased from 8.8 (7.4) to 6.3 (6.6) (p=0.0015) and EULAR) Sjögrens Syndrome Patient Reported Index from 6.4 (1.1) to 5.6 (2.0) (p=0.0174). The mean dryness, fatigue and pain VAS varied from 7.8 (1.8) to 6.2 (2.9) (p=0.0021), 6.9 (1.8) to 6.0 (2.2) (p=0.0606) and 4.6 (2.6) to 4.7 (2.4) (p=0.89), respectively. Salivary flow and Schirmers test did not change. CONCLUSIONS These encouraging results justify future randomised controlled trials of belimumab in a selected target population of pSS patients most likely to benefit from treatment.

Anticardiolipin antibodies in rheumatoid patients treated with etanercept or conventional combination therapy: direct and indirect evidence for a possible association with infections

Objective: To assess the occurrence of anticardiolipin antibodies (ACA) (as well as of anti-DNA antibodies) in patients with rheumatoid arthritis treated with etanercept or combination therapy. Methods: Eight patients treated with etanercept 25 mg twice weekly were studied for a period of 85 weeks. A control group of 39 patients with rheumatoid arthritis undergoing combination treatment (methotrexate (MTX) + cyclosporin A or MTX + chloroquine) were studied for the same period of time. The occurrence of anticardiolipin antibodies (ACA-IgG) and anti-DNA was examined, together with the possible occurrence of infections due to bacteria capable of inducing B cell activation. Results: In 5/8 patients receiving etanercept an increase of ACA-IgG was seen, while anti-DNA became positive in 3/8 patients. A nasal or bronchial infection due to Staphylococcus aureus (Staph aureus) or a urinary tract infection due to E coli, occurred in all five cases. Antibiotic treatment produced a return to normal of ACA-IgG, and also of anti-DNA, in all cases except one. The infectious agent was eradicated in all subjects but one. In the control group Staph aureus was found in the nasal swab in 10/39 subjects; ACA-IgM (followed by ACA-IgG) appeared at the same time as infection occurred in 6/10, while no infection related to the increased ACA-IgM was recorded in the other four. Conclusions: Bacterial DNA, especially that enriched in CpG motifs, is a powerful immunostimulant that may, in some cases, lead to ACA or anti-DNA positivity, once tumour necrosis factor α is blocked. Eradication of the infections leads to a rapid decrease of ACA-IgG and of anti-DNA levels.

Rheumatoid factor positivity rather than anti-CCP positivity, a lower disability and a lower number of anti-TNF agents failed are associated with response to rituximab in rheumatoid arthritis

OBJECTIVES We explored clinical factors associated with a major response to rituximab (RTX) (e.g. ACR >/=50, and European League against Rheumatism (EULAR) moderate to good response) in patients with active long-standing RA and inadequate response to anti-TNF agents or traditional DMARDs. METHODS RTX was used in 110 RA patients in six different Italian centres. The mean disease activity score on 28 joints (DAS28) was 6.4 +/- 0.99 and the mean HAQ was 1.63 +/- 0.68 at baseline. Thirty-two patients (29.1%) underwent RTX after the failure of DMARD therapy, 37 (33.6%) had failed or were intolerant to at least two anti-TNF agents, and 41 (37.3%) had failed or were intolerant to one anti-TNF agent. Univariate and multivariate analyses were performed. RESULTS The number of previous anti-TNF agents (P = 0.043), HAQ (P = 0.023), RF positivity (P < 0.0001) and anti-cyclic citrullinated peptide (anti-CCP) positivity (P = 0.003) were associated with ACR response >or=50 between month +4 and month +6 after starting RTX by univariate analysis. Multivariate analysis confirmed that a lower HAQ, a lower number of anti-TNF agents failed before RTX and RF positivity, but not anti-CCP positivity, were the selected variables associated with an ACR response >or=50, with an accuracy of 84% of the model. Only RF positivity correlated with EULAR moderate to good response both in the univariate and in the multivariate analysis, with an accuracy of 79% of the model. CONCLUSION RF-positive rather than anti-CCP-positive RA patients with lower baseline disability and a lower number of previously failed TNF blockers may be the best candidates to RTX.

BLyS upregulation in Sjögren’s syndrome associated with lymphoproliferative disorders, higher ESSDAI score and B-cell clonal expansion in the salivary glands

OBJECTIVE Primary SS is characterized by an increased risk of lymphoma in patients with prelymphomatous manifestations (i.e. myoepithelial sialadenitis or mixed cryoglobulinaemia). Serum B-lymphocyte stimulator (s-BLyS) levels in SS-related B-cell lymphoproliferative disorders were studied by integrating the results with the disease activity score and with molecular analyses of B-cell expansion in the salivary glands. METHODS Seventy-six primary SS patients (with or without lymphoma or prelymphomatous manifestations), 56 HCV-related cryoglobulinaemic vasculitis patients and 55 controls were studied. s-BLyS and molecular analyses of B-cell expansion in the salivary gland tissues were performed. Patients with SS and persistent parotid swelling underwent parotid biopsy. RESULTS s-BLyS differed between SS subgroups, higher levels being documented in patients with lymphoma or prelymphomatous manifestations vs SS without [1.85 (0.45-4.12) ng/ml vs 1.12 (0.56-1.98) ng/ml; P < 0.0001]. s-BLyS levels significantly correlated with the European League Against Rheumatism (EULAR) SS disease activity index (r = 0.62, P < 0.0001, Spearmans test). Clonal B-cell expansion in the salivary glands, but not polyclonal B-cell expansion, was associated with higher s-BLyS levels [1.98 (0.45-4.12) ng/ml vs 1.15 (0.56-3.25) ng/ml; P = 0.013)]. CONCLUSION Higher s-BLyS levels and tissue clonal B-cell expansion characterize SS with B-cell lymphoproliferative disorders, even at prelymphomatous stages. This subgroup of SS patients showed the highest EULAR SS disease activity index scores. This represents a biologic rationale for targeting both clonal B-cell expansion and s-BLyS overproduction in SS.

HCV-NS3 and IgG-Fc crossreactive IgM in patients with type II mixed cryoglobulinemia and B-cell clonal proliferations.

We demonstrate that in three cases of MC (two with immunocytoma), the IgM-RF+ component of their cryoprecipitated represents the circulating counterpart of the B-cell receptor (BCR) of the monoclonal overexpanded B-cell population. These IgMs were isolated and used to demonstrate a crossreactivity against both hepatitis C virus (HCV) NS3 antigen and the Fc portion of IgG. Epitopes were identified in a fraction of exemplary samples by using epitope excision approach (NS31250–1334 and IgG Fc345–355). The same phenomenon of crossreactivity has been shown to occur in vivo after immunization of a mouse with the NS31251−1270 peptide. To verify if the same reaction was also present in MC samples characterized by an oligo/polyclonal B-cell proliferation, IgM crossreactivity was tested in 14 additional samples. Five out of the 14 were reactive against HCV NS3 and 11 out of 14 were reactive against IgG-Fc peptide. The data support the role of HCV NS3 antigen in a subset of patients with MC, whereas the high frequency of the IgG-Fc epitope suggests that these B cells originate from precursors strongly selected for auto-IgG specificity. We suggest that engagement of specific BCRs by NS3 (or NS3-immunocomplex) antigen could explain the prevalence of IgM cryoglobulins in these patients

Hepatitis C virus infection, mixed cryoglobulinemia and BLyS upregulation: Targeting the infectious trigger, the autoimmune response, or both?

Mixed cryoglobulinemia syndrome (MCsn) is a systemic vasculitis prevalently mediated by immune complexes, i.e., mixed cryoglobulins, and characterized by non-neoplastic B-cell lymphoproliferation favouring the progression into frank B-cell non-Hodgkin lymphoma (NHL) in 5-10% of patients. The hepatitis C virus (HCV) infection is the etiologic agent in the large majority of MCsn cases and chronic antigenic stimulation by HCV is considered a key mechanism sustaining the proliferation of the RF-secreting B-cell clones. Besides chronic antigenic stimulation, cytokines and growth factors may also play a key role in sustaining B-cell overactivation. B-lymphocyte stimulator (BlyS) was recently described as a critical survival factor for B cells, promoting their activation and maturation. Abnormal production of BLyS alters immune tolerance by allowing the survival of autoreactive B cells, thus triggering autoimmune disorders. BLyS inhibits B-cell apoptosis, and B-cell apoptosis is implicated in the pathogenesis of MCsn, as well as of other autoimmune diseases. Both antiviral therapy and B- cell depletive therapy in MCsn may influence BlyS expression. Antiviral therapy, monotherapy against biologic targets downstream viral infection, or the combination of the two, should be optimized in the single patient and stage of the disease, based on disease pathobiology, efficacy and safety issues.

Resistance to rituximab therapy and local BAFF overexpression in Sjogren's syndrome-related myoepithelial sialadenitis and low-grade parotid B-cell lymphoma.

Objective B-cell expansion is a key feature of Sjögren’s syndrome (SS). Accordingly, several studies have reported the benefits of B-cell depletion with anti-CD20 monoclonal antibody (Rituximab) in the treatment of glandular and extraglandular manifestations of SS. Patients with SS are at increased risk of lymphoma development. B-lymphocyte stimulator (BAFF) is an essential cytokine for the control of B-cell maturation and survival, and high levels of BAFF were described in the serum and salivary glands of SS patients, strongly suggesting a crucial role in the proliferation of B cells in SS. Patient and Methods We describe the treatments employed, with particular regards to rituximab therapy, and the histopathologic and biologic studies, in particular BAFF levels in serum and in pathologic tissues before and after B-cell depletion therapy, and the characterization of the cultured epithelial cells obtained by the parotid gland MALT-lymphoma, in a case of a 51-year old woman with primary SS and mixed cryoglobulinaemia type II with features of systemic vasculitis, who developed a bilateral parotid MALT-type lymphoma. Rheumatoid factor (RF), cryoglobulins, BAFF levels were assessed monthly up to month +6, then at the end of follow-up (month +12), as well as peripheral blood CD19-positive B-cell level Results A significant systemic effect of rituximab on B-cell biomarkers was documented, however, the cryoglobulinemic syndrome did not improve and the parotid enlargement did not decrease confirming the failure of B-cell depletion to affect the parotid lymphoma. BAFF levels decreased only under B-cell depletion associated with high-dose steroids. Tissue studies further documented the persistent overexpression of BAFF in the salivary gland pathologic tissue during the disease course. Conclusion Tissue and systemic overexpression of BAFF may have contributed to resistance to rituximab therapy, in MALT lymphoproliferation associated with SS. Thus, alternative treatment strategies should be then considered, possibly including BAFF-targeted approaches.

The CC homozygosis of the -174G>C IL-6 polymorphism predicts a lower efficacy of rituximab therapy in rheumatoid arthritis

Identification of genetic biomarkers of response to biologics in rheumatoid arthritis (RA) is a relevant issue. Being IL-6 a key cytokine for B cell survival, the interleukin-6 (IL-6) -174G>C and the IL-6 receptor (IL-6R) D358A gene polymorphisms were investigated in 158 RA patients treated with rituximab (RTX). One hundred and twenty-eight (81.0%) were RF positive and 126 (79.7%) were anti-CCP positive. Response to therapy was evaluated at the end of the sixth month after the first RTX infusion, by using both the EULAR and the ACR criteria. The possible relationship with IL-6 serum levels was also studied. By univariate analysis, lack of response by the EULAR criteria was more prevalent in RA patients with the IL-6 -174 CC genotypes (39.1%), than in the GC/GG patients (18.5%) (OR 2.83; 95%CI=1.10-7.27; p=0.031). A good response was noticed in only one patient (4.3%) with the IL-6 -174 CC genotype, while it was present in 24.4% of GG/GC cases (p=0.06). By stepwise multivariate analysis (including RA duration, baseline DAS28, baseline HAQ, RF status, anti-CCP status and IL-6 genotype as covariates), the IL-6 -174CC genotype was selected as an independent predictor of no response to RTX by both EULAR and ACR≥50 criteria, while the IL-6R polymorphism resulted as not associated. No definite association between gene polymorphisms and IL-6 serum levels was noticed. Present results suggest a possible role for IL-6 genotyping to better plan treatment with RTX in RA, and larger studies are worthwhile.

Efficacy and safety of belimumab given for 12 months in primary Sjögren’s syndrome: the BELISS open-label phase II study

OBJECTIVE To report the efficacy and safety of long-term treatment of SS with belimumab, targeting the B-cell-activating factor. METHODS Patients with primary SS were included in the BELISS open-label phase II study, a 1-year open-label trial, if they were positive for anti-SSA or anti-SSB antibodies and had systemic complications or persistent salivary gland enlargement or early disease or biomarkers of B-cell activation. They received belimumab, 10 mg/kg i.v., at weeks 0, 2 and 4 and then every 4 weeks; if response was observed at week 28, or if the clinician and the patient agreed to continue the study in the absence of side effects, treatment was continued for 1 year. Efficacy and safety were analysed during the 1-year period of treatment. RESULTS Among the 30 patients recruited, 28 were evaluated at week 28 as already reported. Nineteen terminated the 52-week study, 15 of them being responders and 4 non-responders at week 28. Thirteen of the 15 responders at week 28 also responded at week 52 (86.7%). The improvement in the EULAR Sjögrens Syndrome Disease Activity Index and EULAR Sjögrens Syndrome Patient Reported Index scores observed at week 28 showed a trend to further improvement at week 52, and the amelioration of peculiar EULAR Sjögrens Syndrome Disease Activity Index domains (glandular, lymphadenopathy, articular) appeared of particular relevance. The decrease in biomarkers of B-cell activation observed at week 28 persisted unchanged until week 52, with RF decreasing further. Salivary flow, Schirmers test and the focus score of salivary biopsy did not change. Safety of treatment was good. CONCLUSION Long-term treatment with belimumab may be beneficial in SS. Randomized, double-blind, controlled studies in larger populations are encouraged.

The 158VV Fcgamma receptor 3A genotype is associated with response to rituximab in rheumatoid arthritis: results of an Italian multicentre study

Objective The polymorphism 158V/F of Fc fragment of IgG (FCGR) type 3A may influence the response to rituximab (RTX) in rheumatoid arthritis (RA). We investigated the FCG3A polymorphism in a large cohort of RA patients treated with RTX, also by considering the possible loss of response from month +4 to +6 after RTX and the presence of established predictors of response. Methods The study analysed 212 RA patients. European League Against Rheumatism (EULAR) response was evaluated at months +4 and +6 after the first RTX infusion. The FCGR3A polymorphism was analysed by PCR followed by Sanger sequencing. Results The FCGR3A genotypes were associated with EULAR response (good or moderate) at month +6 (response in 34/38 (89.5%) VV vs 70/106 (66%) VF and in 51/77 (66.2%) FF patients; p=0.01), but not at month +4 (response in 32/37 (86.5%) VV vs 69/102 (67.6%) VF and 53/73 (72.6%) FF patients; p=0.09). Loss of response was observed only in VF and FF carriers ((VV vs VF vs FF: 0/37 (0%) vs 11/102 (10.8%) vs 12/73 (16.4%); p=0.02)). Probability of response at month +6 was very high when at least two of the three following items selected by multivariate analysis were present: positive rheumatoid factor and/or anticyclic citrullinated peptide antibodies, previous treatment with ≤1 anti-tumor necrosis factor (TNF) agent, and 158VV FCGR3A genotype (p<0.0001; OR 7.9, 95% CI 4.1 to 15.1). Conclusions The 158VV FCGR3A genotype was associated with response to RTX in a large cohort of RA patients. Patient genotyping may be helpful to plan RTX treatment, and may be integrated with clinical predictors.