Joop P. van de Merwe

Prevalence of interferon type I signature in CD14 monocytes of patients with Sjögren's syndrome and association with disease activity and BAFF gene expression

Objective To determine the prevalence of upregulation of interferon (IFN) type I inducible genes, the so called ‘IFN type I signature’, in CD14 monocytes in 69 patients with primary Sjögrens syndrome (pSS) and 44 healthy controls (HC) and correlate it with disease manifestations and expression of B cell activating factor (BAFF). Methods Expression of IFI44L, IFI44, IFIT3, LY6E and MX1 was measured using real time quantitative PCR in monocytes. Expression values were used to calculate IFN type I scores for each subject. pSS patients positive for the IFN type I signature (IFN score≥10) and patients negative for the signature (IFN score<10) were then compared for clinical disease manifestations and BAFF expression. A bioassay using a monocytic cell line was performed to study whether BAFF mRNA expression was inducible by IFN type I activity in serum of patients with pSS. Results An IFN type I signature was present in 55% of patients with pSS compared with 4.5% of HC. Patients with the IFN type I signature showed: (a) higher EULAR Sjögrens Syndrome Disease Activity Index scores; higher anti-Ro52, anti-Ro60 and anti-La autoantibodies; higher rheumatoid factor; higher serum IgG; lower C3, lower absolute lymphocyte and neutrophil counts; (b)higher BAFF gene expression in monocytes. In addition, serum of signature-positive patients induced BAFF gene expression in monocytes. Conclusions The monocyte IFN type I signature identifies a subgroup of patients with pSS with a higher clinical disease activity together with higher BAFF mRNA expression. Such patients might benefit from treatment blocking IFN type I production or activity.

Systemic increase in type I interferon activity in Sjögren's syndrome: a putative role for plasmacytoid dendritic cells

In the salivary glands of primary Sjögrens syndrome (pSjS) patients, type I IFN activity is increased, but systemic levels of type I IFN proteins are rarely detected. This study focused on the systemic activity of type I IFN in pSjS, as well as the role of peripheral plasmacytoid dendritic cells (pDC). Monocytes obtained from pSjS patients showed an increased expression of 40 genes. Twenty‐three of these genes (58%), including IFI27, IFITM1, IFIT3 and IFI44, were inducible by type I IFN. pSjS serum had an enhanced capability of inducing IFI27, IFITM1, IFIT3 and IFI44 in the monocytic cell line THP‐1, likely due to the action of IFN‐β. This effect could be inhibited by blocking the type I IFN receptor, supporting a high type I IFN bioactivity in pSjS serum. In addition, circulatory pDC showed increased expression of CD40. This expression was correlated to the expression level of the type I IFN‐regulated genes IFI27 and IFITM1 in monocytes of the same individual. This study indicates that the increased type I IFN activity observed in pSjS patients is not only a local but also a systemic phenomenon and points to pDC as a possible source of this activity.

Interstitial cystitis and systemic autoimmune diseases.

The cause of interstitial cystitis, a chronic disease that affects the bladder, is unknown. Autoantibodies, such as those against nuclear and bladder epithelium antigens, have been found in patients with interstitial cystitis, but these are likely to be secondary to the disease. No data support a direct causal role of autoimmune reactivity in the pathogenesis of interstitial cystitis. Indirect evidence, however, does support a possible autoimmune nature of interstitial cystitis, such as the strong female preponderance and the clinical association between interstitial cystitis and other known autoimmune diseases within patients and families. The strongest association occurs between interstitial cystitis and Sjögrens syndrome. Increasing evidence suggests a possible role of autoantibodies to the muscarinic M3 receptor in Sjögrens syndrome. The M3 receptor is also located on the detrusor muscle cells of the bladder and mediates cholinergic contraction of the urinary bladder and other smooth muscle tissues. Autoantibodies to the M3 receptor might be important in both the early noninflammatory and the late inflammatory features of interstitial cystitis.

Two different types of sialoadenitis in the NOD- and MRL/lpr mouse models for Sjögren's syndrome: a differential role for dendritic cells in the initiation of sialoadenitis?

Sjögren’s syndrome is an autoimmune disease that primarily affects the salivary and lacrimal glands. In these glands, focal lymphocytic infiltrates develop. Little is known about the initiation of this autoimmune disease. Antigen-presenting cells (APC) such as dendritic cells (DC) can play a role in the initiation of autoimmunity. To date, no data on the presence of DC in Sjögren’s syndrome are available. Several mouse strains, the nonobese diabetic (NOD) and the MRL/lpr mouse, can be used as models for Sjögren’s syndrome. We compared the development of sialoadenitis in the submandibular glands (SMG) of NOD and MRL/lpr mice with particular focus on the presence of APC. DC, macrophages, T cells, and B cells in the SMG were studied by means of immunohistochemistry, after which positively stained cells were quantified. NOD-severe combined immunodeficiency (SCID) mice were used to study the presence of APC in the SMG in the absence of lymphocytes. Before lymphocytic infiltration, increased numbers of DC were detected in the SMG of NOD mice compared with those numbers in control mice and MRL/lpr mice, which suggests that DC play a role in the initiation of sialoadenitis in NOD mice. In the SMG of NOD mice, lymphocytic infiltrates organized in time. In MRL/lpr mice, however, lymphocytic infiltrates were already organized at the time of appearance. This organization was lost over time. In conclusion, two types of sialoadenitis are described in two mouse models for Sjögren’s syndrome. Differences exist with regard to early events that may lead to the development of sialoadenitis and to the composition and organization of inflammatory infiltrates. It is possible that different types of sialoadenitis also exist in humans and that the pathogenetic process in both the early and late phases of the autoimmune reaction differs among patients.

Systemic aspects of interstitial cystitis, immunology and linkage with autoimmune disorders

Abstract It is recognized that interstitial cystitis (IC) is often associated with a number of diseases such as allergies, irritable bowel syndrome, fibromyalgia, inflammatory bowel disease (Crohns disease and ulcerative colitis), systemic lupus erythematosus, and Sjögrens syndrome.

MxA as a clinically applicable biomarker for identifying systemic interferon type I in primary Sjögren's syndrome

Objective To establish an easy and practical assay for identifying systemic interferon (IFN) type I bioactivity in patients with primary Sjögrens syndrome (pSS). The IFN type I signature is present in over half of the pSS patients and identifies a subgroup with a higher disease activity. This signature is currently assessed via laborious expression profiles of multiple IFN type I-inducible genes. Methods In a cohort of 35 pSS patients, myxovirus-resistance protein A (MxA) was assessed as a potential biomarker for type I IFN activity, using an enzyme immunoassay (EIA) on whole-blood and flow cytometric analyses (fluorescence-activated cell sorting, FACS) of isolated CD14 monocytes. In addition, potential biomarkers such as CD64, CD169 and B cell-activating factor (BAFF) were simultaneously analysed in CD14 monocytes using FACS. The IFNscore, a measure for total type I IFN bioactivity, was calculated using expression values of the IFN type I signature genes—IFI44, IFI44L, IFIT3, LY6E and MX1—in CD14 monocytes, determined by real-time quantitative PCR. Results IFNscores correlated the strongest with monocyte MxA protein (r=0.741, p<0.001) and whole-blood MxA levels (r=0.764, p<0.001), weaker with CD169 (r=0.495, p<0.001) and CD64 (r=0.436, p=0.007), and not at all with BAFF protein. In particular, whole blood MxA levels correlated with EULAR Sjögrens Syndrome Disease Activity Index scores and numerous clinical pSS parameters. Interestingly, patients on hydroxychloroquine showed reduced MxA levels (EIA, p=0.04; FACS p=0.001). Conclusions The MxA assays were excellent tools to assess IFN type I activity in pSS, MxA-EIA being the most practical. MxA levels associate with features of active disease and are reduced in hydroxychloroquine-treated patients, suggesting the clinical applicability of MxA in stratifying patients according to IFN positivity.

Interstitial cystitis/bladder pain syndrome and nonbladder syndromes: Facts and hypotheses

3 p s I Since the 19th century, searches for the pathogenesis of interstitial cystitis/bladder pain syndrome (IC/BPS) have concentrated on the bladder. Howver, recent work has shown that patients with IC/BPS re more likely than controls to have syndromes with ymptoms beyond the bladder and even the pelvis. These ndings suggest that research into IC/BPS etiology hould not focus only on the bladder. The sequence of investigation of nonbladder synromes (NBSs) and IC/BPS has been similar to that for ost medical research: case series generating hypotheses hat are then tested in controlled studies. For instance, an ften-cited survey of patients with IC/BPS showed an pparently high prevalence of fibromyalgia (FM), chronic atigue syndrome (CFS), irritable bowel syndrome (IBS), llergy, asthma, vulvodynia, and several other diseases nd syndromes. Recent controlled studies have confirmed most of these findings. We believe that these studies have integrated important facts into the knowledge of IC/BPS. The present report presents these facts, formulates the hypotheses they generate, and suggests pathways to test these hypotheses.

Professional antigen presenting cells in minor salivary glands in Sjögren's syndrome : Potential contribution to the histopathological diagnosis?

Sjögren’s syndrome is an autoimmune disease in which lymphocytic infiltrates develop in the salivary and lacrimal glands. We have shown that dendritic cells (DC) infiltrate the submandibular gland of the nonobese diabetic (NOD) mouse, a mouse model for Sjögren’s syndrome, before lymphocytic infiltration, suggesting that these antigen-presenting cells (APC) may play a role in the initiation of Sjögren’s syndrome. In later stages, DC and macrophages also form an important part of the infiltrate of the NOD sialoadenitis. To find out if DC and macrophages form part of the infiltrate in Sjögren’s syndrome as well, and to determine whether they may be useful in the histopathological diagnosis of Sjögren’s syndrome, we studied their presence in minor salivary glands (MSG) of patients with Sjögren’s syndrome and patients with focal lymphocytic sialoadenitis (FLS), but without clinical or serological criteria of Sjögren’s syndrome. Immunohistochemistry was applied, followed by semiquantitative analysis. DC and macrophages were present in all MSG; however, there were clear differences in marker expression between Sjögren’s syndrome and FLS, on the one hand, and control tissue, on the other hand. CD1a+ DC and RFD9+ macrophages were mainly observed in MSG in which a focal lymphocytic infiltrate was present. In fact, the diffuse presence of single CD1a+ DC and RFD9+ macrophages correlated closely with the presence of a focal lymphocytic infiltrate in the MSG. This indicates that these cells could be of help during the evaluation of a MSG. Because the detection of APC is technically less cumbersome than a focal score, this parameter may perhaps replace the focal score in the histopathological diagnosis of Sjögren’s syndrome. This study therefore prompts further investigation focusing on the presence of CD1a+ and RFD9+ cells in the MSG of a large cohort of patients.

The bladder pain/interstitial cystitis symptom score: development, validation, and identification of a cut score.

BACKGROUND There is a need to develop a self-report measure that reliably identifies moderate to severe bladder pain syndrome (BPS) patients for inclusion into clinical trials to assess the efficacy of new BPS treatments. OBJECTIVE To develop and validate a patient-reported symptom-based instrument, the Bladder Pain/Interstitial Cystitis Symptom Score (BPIC-SS), for clinical trial eligibility of BPS patients. DESIGN, SETTING, AND PARTICIPANTS Stage 1: Qualitative concept elicitation (CE) interviews were conducted with BPS patients in France (n=12), Germany (n=12), and the United States (US) (n=20), and overactive bladder (OAB) (n=10) patients in the US for comparison. Stage 2: Cognitive debriefing (CD) interviews were performed with US BPS patients (n=20). Stage 3: An observational study with 99 BPS, 99 OAB, and 100 healthy participants in the US was used to perform item reduction, identify cut scores, and validate the measure. A cut score was defined using logistic regression and receiver operating characteristic curves. Psychometric properties, including test-retest reliability, were assessed. MEASUREMENTS In addition to the BPIC-SS, the Pelvic Pain and Urgency/Frequency Patient Symptom Scale, the Interstitial Cystitis Symptom Index, a Clinician Global Impression of Severity, and a Patient Global Impression of Change were included in the observational study. RESULTS AND LIMITATIONS In CE, reported symptoms were bladder pain, persistent urge to urinate, and high urinary frequency. In CD, 13 items were deleted, and 15 were retained. Based on validation analyses, qualitative findings, and clinical relevance, the instrument was reduced to eight items that had strong sensitivity (0.72) and specificity (0.86) with a cut score ≥19 to determine clinical trial inclusion. Psychometric properties were strong. CONCLUSIONS The BPIC-SS is a reliable, valid, and appropriate questionnaire to select BPS/interstitial cystitis patients for clinical trials.

Retinal vasculitis occurring with common variable immunodeficiency syndrome

PURPOSE To report severe retinal vasculitis causing decreased vision in three patients with the common variable immunodeficiency syndrome. METHOD Case report. Three patients with common variable immunodeficiency syndrome developed decreased vision secondary to retinal vasculitis. Fluorescein angiography was performed in all three patients. Peribulbar injections were given in one patient, and two patients were treated with oral steroids and cyclosporin. RESULTS All three patients were young and had classic common variable immunodeficiency syndrome. Bilateral retinal vasculitis and diffuse retinal edema were present in all three patients, and two patients had retinal neovascularization in the absence of ischemia. No evidence of intraocular infection was present, and none was detected systematically. Visual acuity decreased in five of the six eyes and was responsive to treatment in only one patient (both eyes). CONCLUSION Retinal vasculitis may be another autoimmune manifestation of common variable immunodeficiency syndrome.