Rodney Pollard

Preclinical validation of salivary biomarkers for primary Sjögren’s syndrome

Sjögrens syndrome (SS) is a systemic autoimmune disease with a variety of presenting symptoms that may delay its diagnosis. We previously discovered a number of candidate salivary biomarkers for primary SS using both mass spectrometry and expression microarray analysis. In the current study, we aimed to verify these candidate biomarkers in independent patient populations and to evaluate their predictive values for primary SS detection.

Treatment of Mucosa-associated Lymphoid Tissue Lymphoma in Sjögren’s Syndrome: A Retrospective Clinical Study

Objective. To retrospectively analyze the clinical course of patients with mucosa-associated lymphoid tissue (MALT)-type lymphoma of the parotid gland and associated Sjögren’s syndrome (SS). Methods. All consecutive patients with SS and MALT lymphoma (MALT-SS) diagnosed in the University Medical Center Groningen between January 1997 and January 2009 were analyzed. Clinical course and treatment outcome of SS and MALT lymphoma were evaluated. Results. From a total of 329 patients with SS, 35 MALT-SS patients were identified, with a median followup of 76 months (range 16–153 mo). MALT lymphoma was localized in the parotid gland in all cases. Treatment consisted of “watchful waiting” (n = 10), surgery (n = 3), radiotherapy (n = 1), surgery combined with radiotherapy (n = 2), rituximab only (n = 13), or rituximab combined with chemotherapy (n = 6). Complete response was observed in 14 patients, partial response in 1 patient, and stable disease in 20 patients. In 6 of 7 patients with initially high SS disease activity (M-protein, cryoglobulins, IgM rheumatoid factor > 100 KIU/l, severe extraglandular manifestations), MALT lymphoma progressed and/or SS disease activity increased after a median followup of 39 months (range 4–98 mo), necessitating retreatment. Only 1 patient with MALT who had low SS disease activity showed progression of lymphoma when left untreated. Conclusion. An initially high SS disease activity likely constitutes an adverse prognostic factor for progression of lymphoma and/or SS. Such patients may require treatment for both MALT lymphoma and SS. In SS patients with localized asymptomatic MALT lymphoma and low SS disease activity, a “watchful waiting” strategy seems justified.

Serum levels of BAFF, but not APRIL, are increased after rituximab treatment in patients with primary Sjögren's syndrome: data from a placebo-controlled clinical trial

B cell depletion therapy with rituximab (RTX; 2 weekly infusions of 1000 mg, premedication: 100 mg prednisolone) in primary Sjogrens syndrome (pSS) patients is effective in reducing subjective and objective symptoms.1 As B cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are important cytokines involved in B cell survival and activation, we assessed in pSS patients included in a double-blind, randomised, placebo-controlled trial1 the effects of RTX on serum BAFF and APRIL levels up to 48 weeks after RTX. Serum concentrations of BAFF and APRIL were measured by ELISA using kits from RD median 1277 pg/ml (range 907–3802 pg/ml)) compared with healthy controls (n=10; median 983 pg/ml (range 600–1564 pg/ml)); p<0.01; figure 1A). Also, baseline serum APRIL levels were significantly higher in pSS patients (median 15 098 pg/ml (range 1891–228 591 pg/ml)) than in healthy controls (median 1965 pg/ml (range 889–4567 pg/ml); p<0.05; …

Towards personalised treatment in primary Sjögren's syndrome: baseline parotid histopathology predicts responsiveness to rituximab treatment.

Objectives The aims of this study were (1) to assess the effect of rituximab (RTX; anti-CD20) treatment in patients with primary Sjögrens syndrome (pSS) based on sequential parotid biopsies obtained in a placebo-controlled, randomised clinical trial, and (2) to assess the prognostic value of the histological characteristics of parotid gland tissue with regard to responsiveness to RTX treatment. Methods In a double-blinded, placebo-controlled trial, sequential parotid gland biopsies were taken from 20 RTX-treated and 10 placebo-treated patients with pSS, at baseline and 12 weeks after treatment. The relative amount of lymphocytic infiltrate (stained for CD45), absolute number of T cells and B cells per mm2 parenchyma (stained for CD3 and CD20, respectively), focus score, number of germinal centres and of lymphoepithelial lesions per mm2 in parotid gland parenchyma were assessed. Histopathological data were compared between clinical responders (decrease in European League Against Rheumatism Sjögrens Syndrome Disease Activity Index (ESSDAI) score of ≥3 at 12 weeks compared with baseline) and non-responders (change in ESSDAI<3) to RTX treatment. Results In RTX-treated patients, a significant reduction in the number of CD20+ B cells/mm2 parenchyma was observed, while no such reduction was observed in placebo-treated patients. The number of CD3+ T cells/mm2 in parenchyma did not change in either group. Furthermore, the number and the severity of lymphoepithelial lesions/mm2 and number of germinal centres/mm2 was significantly reduced in RTX-treated patients, but did not change in placebo-treated patients. When comparing the pretreatment characteristics of clinical responders with non-responders, the median number of CD20+ B cells/mm2 parenchyma at baseline was significantly higher in responders (1871 vs 353 cells/mm2, p<0.05). Other histopathological baseline characteristics were not predictive for response to RTX treatment. Conclusions RTX treatment in pSS leads to a major reduction of lymphocytic infiltration and to fewer B cells, germinal centres and lymphoepithelial lesions in parotid gland parenchyma. A high pretreatment number of CD20+ B cells/mm2 parotid gland parenchyma predicts better responsiveness of patients with pSS to RTX treatment. Pretreatment parotid gland histopathological characteristics could therefore contribute to a more personalised treatment approach to pSS.

Persistence of immunoglobulin-producing cells in parotid salivary glands of patients with primary Sjogren's syndrome after B cell depletion therapy

Objectives To assess the persistence of immunoglobulin-producing cell populations in the parotid salivary glands of patients with primary Sjögrens syndrome (pSS) after B cell depletion therapy with rituximab. Methods Thirteen patients with pSS and four control patients were included in this study. Patients with pSS were treated with rituximab or placebo. Sequence analysis was carried out on IgA- and IgG-encoding transcripts extracted from parotid salivary gland biopsy specimens taken before treatment and at 12–16 and 36–52 weeks after treatment. Results At baseline, many clonally related sequences were seen in patients with pSS. The number of clonal expansions was significantly higher in patients with pSS than in control patients. Clonal expansions were composed of IgA- and/or IgG-expressing cells. Rituximab did not significantly alter the degree of clonal expansions. Groups of clonally related cells had members which were shared between biopsy specimens taken before and after treatment. Mutation frequencies of immunoglobulin sequences from clonally related cells in patients with pSS were higher after treatment. Conclusions Rituximab treatment does not alter the characteristic features of increased clonal expansions seen in the parotid salivary glands of patients with pSS. The presence of clonally related immunoglobulin-producing cells before and after rituximab treatment strongly suggests that immunoglobulin-producing cells persist in salivary glands of patients with pSS despite B cell depletion. The presence of mixed isotype expression within groups of clonally related cells indicates local class switching in salivary glands of patients with pSS. Persistent immunoglobulin-producing cells may underlie disease relapse after treatment.

Predominantly proinflammatory cytokines decrease after B cell depletion therapy in patients with primary Sjögren's syndrome

Cytokines are critical in initiating and perpetuating the chronic inflammatory response in primary Sjogrens syndrome (pSS).1 Rituximab has beneficial effects on disease activity in pSS patients2 and results in a rise in B cell activating factor (BAFF) levels.3 Whether (elevated) levels of other (proinflammatory) cytokines are affected was addressed in this study. This information is important for understanding of the effect of rituximab in pSS. Twenty-eight patients with early-onset pSS2 treated with rituximab (n=18) or placebo (n=10), and 10 age-matched and sex-matched healthy controls (HCs) were assessed for presence of cytokines/chemokines in serum, using a multiplex-25 bead array assay (Invitrogen, Breda, The Netherlands). The following cytokines and chemokines were analysed: GM-CSF, IL-1β, IL-1Ra, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p40/p70, IL-13, IL-15, IL-17, IFN-α, IFN-γ, TNF-α, MCP-1/CCL2, MIP-1α/CCL3; MIP-1β/CCL4, RANTES/CCL5, Eotaxin/CCL11, MIG/CXCL9 and IP-10/CXCL10. At baseline, levels for nearly all cytokines/chemokines were significantly higher in pSS patients than …

Systems analysis of primary Sjögren's syndrome pathogenesis in salivary glands identifies shared pathways in human and a mouse model

IntroductionPrimary Sjögrens syndrome (pSS) is a chronic autoimmune disease with complex etiopathogenesis. Despite extensive studies to understand the disease process utilizing human and mouse models, the intersection between these species remains elusive. To address this gap, we utilized a novel systems biology approach to identify disease-related gene modules and signaling pathways that overlap between humans and mice.MethodsParotid gland tissues were harvested from 24 pSS and 16 non-pSS sicca patients and 25 controls. For mouse studies, salivary glands were harvested from C57BL/6.NOD-Aec1Aec2 mice at various times during development of pSS-like disease. RNA was analyzed with Affymetrix HG U133+2.0 arrays for human samples and with MOE430+2.0 arrays for mouse samples. The images were processed with Affymetrix software. Weighted-gene co-expression network analysis was used to identify disease-related and functional pathways.ResultsNineteen co-expression modules were identified in human parotid tissue, of which four were significantly upregulated and three were downregulated in pSS patients compared with non-pSS sicca patients and controls. Notably, one of the human disease-related modules was highly preserved in the mouse model, and was enriched with genes involved in immune and inflammatory responses. Further comparison between these two species led to the identification of genes associated with leukocyte recruitment and germinal center formation.ConclusionOur systems biology analysis of genome-wide expression data from salivary gland tissue of pSS patients and from a pSS mouse model identified common dysregulated biological pathways and molecular targets underlying critical molecular alterations in pSS pathogenesis.

In primary Sjögren's syndrome high absolute numbers and proportions of B cells in parotid glands predict responsiveness to rituximab as defined by ESSDAI, but not by SSRI

With great interest we have read the letter to the editor by Cornec et al 1 regarding our paper ‘Towards personalised treatment in primary Sjogrens syndrome (pSS): baseline parotid histopathology predicts responsiveness to rituximab treatment’.2 In essence, we showed in our paper that absolute numbers of CD20+ cells/mm2 of parenchyma of parotid gland tissue are predictive for the responsiveness of patients with pSS to rituximab (RTX) treatment. Cornec et al argue that there is a discrepancy in outcomes presented in their study and our study,1 as they observed that a high proportion of minor salivary gland B cells predict the absence of a clinical response to RTX.3 As we will show and explain here, there is no inconsistency between the two studies and most of the apparent discrepancy is likely the result of differences in how the tissues are analysed and how the disease activity is established. A major difference in the two studies is how B cells are assessed in tissue sections of salivary gland biopsies of patients with pSS before (and after) RTX treatment. We measured absolute numbers of CD20+ B cells/mm2 of parenchyma, while Cornec et al assessed the proportion of B cells.1 ,3 Obviously, even when there is a change in absolute numbers of B cells in the tissue, the B/T cell ratio still can remain the same. Thus, although higher numbers of B cells, do not need to be reflected per se in higher proportions of B cells, we also found in our study that patients with higher absolute numbers of B cells in the glandular tissue, had a higher B/B+T cell ratio. Furthermore, responders to RTX, as defined by a decrease in European League Against …