Serum β2 microglobulin correlates with the new ESSDAI in patients with Sjögren's syndrome

Clinical and laboratory evaluation of sicca complaints: distinctive aspects of primary, secondary and non-Sjogren syndrome

Background

Sjögren Syndrome (SS) is a systemic autoimmune disease with a wide spectrum of manifestations that can lead to misdiagnosis. This study describes and compares demographic, clinical, serological, and histopathological data from subjects with SS and non-Sjögren Syndrome (NSS). It also details specific features within the primary SS (pSS) and secondary SS (sSS) groups identifying sub-groups.

Methods

The sample included individuals referred to an academic medical center in Brazil for investigation of SS from 2012 to 2020. Patients were retrospectively classified as primary SS (pSS), secondary SS (sSS), or NSS, based on the American-European Consensus Group criteria (AECG-2002), after multi-professional clinical and laboratory evaluation.

Results

A total of 676 individuals were screened and 510 (75.4%) completed the assessments; 198 patients were classified as pSS, 149 as sSS, and 163 as NSS. Symptoms and glandular dysfunction tests were similar in the groups. Concerning pSS, extraglandular manifestations were present in 59% of patients; the elderly had more dry symptoms and peripheral neurological disorders; and 2.5% developed non-Hodgkin lymphoma. In sSS, each overlap promoted distinct clinical and laboratory variants. Several alternative diagnoses were identified as a cause of sicca complex in NSS group.

Conclusions

The diagnosis of SS remains a challenge behind dryness. Up to 31% of the suspected cases had other conditions associated to the symptoms. Histopathological analysis of LSG and SSa determined the diagnostic. Aging in pSS and overlap disease in sSS were responsible for distinct phenotypes and characteristic sub-groups in SS.

Recommendations for evaluation and diagnosis of extra-glandular manifestations of primary sjogren syndrome: results of an epidemiologic systematic review/meta-analysis and a consensus guideline from the Brazilian Society of Rheumatology (articular, pulmonary and renal)

Sjogren's Syndrome (SS) is an autoimmune disease characterized by lymphocytic infiltration of the exocrine glands and other organs, associated with sicca syndrome but also with systemic involvement with varying degrees of severity. Despite their importance, these systemic manifestations are not routinely evaluated and there is no homogenous approach to their diagnosis or evaluation. To close this gap, a panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis on the identification of epidemiologic and clinical features of these manifestations and made recommendations based on the findings. Agreement between the experts was achieved using the Delphi method. The first part of this guideline summarizes the most important topics, and 11 recommendations are provided for the articular, pulmonary, and renal care of SS patients.

Biomarkers of B cell activation in autoimmune connective tissue diseases: More than markers of disease activity

B cells play a central role in the pathogenesis of many autoimmune diseases, acting as antigen-presenting cells, producing inflammatory cytokines, and acting as a source of autoantibodies after differentiating into plasma cells. In this review, we aim to summarize and synthesize the literature for the utility of biomarkers of B cell activation (plasma immunoglobulins (Ig), free light chains (FLCs), and beta-2 microglobulin (β2M)) in monitoring inflammatory rheumatic connective tissue diseases, such as Sjogren's syndrome (SS), systemic lupus erythematosus (SLE), dermatomyositis (DM), and systemic sclerosis (SSc). Clinically, it is quite difficult to gauge prognosis in these conditions as there, historically, have not been many quantitative markers of disease activity available. From our extensive literature review, Ig, FLC, and β2M may function as invaluable prognostic markers of ongoing disease activity, and potentially as biomarkers for response to therapy or disease relapse. They are inexpensive and unsophisticated tests that are vastly underused in the setting of autoimmune disease. However, clinicians still need to be aware of the potential of false positives in times of infection or plasma cell dyscrasia, as these disease states can artificially increase these biomarkers. Ultimately, the utility of serum Ig, FLCs, and β2M is clearly delineated in SS and SLE, and least investigated in DM, and additional prospective studies utilizing these biomarkers, and specific B cell targeted therapies are still needed.

Current and future therapies for primary Sjögren syndrome

Primary Sjögren syndrome (pSS) is a systemic autoimmune disease that is characterized by a triad of symptoms that affect all patients (dryness, pain and fatigue). In addition, systemic involvement can affect between one-third and one-half of patients. The management of patients with pSS has been negatively affected by a lack of effective treatments; however, knowledge of the epidemiology of pSS has increased, and advances in developing classification criteria, systemic disease activity scoring and patient-reported outcomes have been made during the past decade. Progress has also been made in understanding the mechanisms that underlie the pathogenesis of pSS, which has enabled a more targeted therapeutic approach to be taken. At present, therapeutic decisions rely on the evaluation of symptoms and systemic manifestations and are mostly formed on the basis of experience rather than evidence, and on similarities with other autoimmune diseases, although the 2019 management recommendations from EULAR are now being used to inform clinical management of pSS. This Review summarizes the available evidence for systemic treatments for pSS and includes discussions of advances in outcome assessment, the current evidence for DMARD use and an overview of promising future therapeutics.

Persistent serological activity in primary Sjögren's syndrome

To assess the presence of persistent serological activity and its association with clinical outcomes in primary Sjögren's syndrome. Clinical charts of 275 patients were reviewed retrospectively. Persistent serological activity was defined as an increase IgG ≥ 1.6 mg/dL or globulins > 3.7 g/dL or diminished C3 < 52 mg/dL or C4 < 12 mg/dL at least during two consecutive visits during a year (index period). The ClinESSDAI at the index period and the cumulative ClinESSDAI and the SSDDI at the last medical appointment were scored. A total of 159 patients with complete serological data were included mostly women and median disease duration of 10.2 years. Persistent serological activity was identified in 85 patients (53.1%). Only 13 patients changed their status to serological inactivity though the follow-up. Comparison of patients with (n = 85) versus without persistent serological activity (n = 74) showed that the first group had a higher frequency of impaired non-stimulated salivary flow, anti-La/SSB antibody, and RF, as well as higher ClinESSDAI scores. The most affected domains were the constitutional, glandular, cutaneous, renal, and hematological domains. On logistic regression analysis, the RF (OR 6.4, 95% CI 1.8-22, p = 0.003), the renal (OR 12.8, 95% CI 1.7-92, p = 0.01), and the hematological involvement (OR 4.7, 95% CI 1.6-13.4, p = 0.004) remained associated. Half of the patients studied had persistent serological activity, being this status constant through the follow-up. Persistent serological activity was associated with positive RF and higher ESSDAI scores due to hematological and renal activity. Scoring serological activity is an important issue in SS patients.

B-cell activity markers are associated with different disease activity domains in primary Sjögren's syndrome

Objectives

B-cell activating factor (BAFF), β-2 microglobulin (β2M) and serum free light chains (FLCs) are elevated in primary SS (pSS) and associated with disease activity. We aimed to investigate their association with the individual disease activity domains of the EULAR Sjögren’s Syndrome Disease Activity Index (ESSDAI) in a large well-characterized pSS cohort.

Methods

Sera from pSS patients enrolled in the UK Primary Sjögren’s Syndrome Registry (UKPSSR) (n = 553) and healthy controls (n = 286) were analysed for FLC (κ and λ), BAFF and β2 M. Pearson correlation coefficients were calculated for patient clinical characteristics, including salivary flow, Schirmer’s test, EULAR Sjögren’s Syndrome Patient Reported Index and serum IgG levels. Poisson regression was performed to identify independent predictors of total ESSDAI and ClinESSDAI (validated ESSDAI minus the biological domain) scores and their domains.

Results

Levels of BAFF, β2M and FLCs were higher in pSS patients compared to controls. All three biomarkers associated significantly with the ESSDAI and the ClinESSDAI. BAFF associated with the peripheral nervous system domain of the ESSDAI, whereas β2M and FLCs associated with the cutaneous, biological and renal domains. Multivariate analysis showed BAFF, β2M and their interaction to be independent predictors of ESSDAI/ClinESSDAI. FLCs were also shown to associate with the ESSDAI/ClinESSDAI but not independent of serum IgG.

Conclusion

All biomarkers were associated with total ESSDAI scores but with differing domain associations. These findings should encourage further investigation of these biomarkers in longitudinal studies and against other disease activity measures.

Salivary gland ultrasonography as a predictor of clinical activity in Sjögren's syndrome

Purpose

Primary Sjögren’s syndrome is a multisystem autoimmune disease characterized by hypofunction of salivary and lacrimal glands and possible multi-organ system manifestations. Over the past 15 years, three sets of diagnostic criteria have been proposed, but none has included salivary gland ultrasonography. However, recent studies support its role in the diagnosis and prognostic evaluation of patients with Sjögren’s syndrome. This study aimed to determine the value of salivary gland ultrasonography in the diagnosis and prognosis of Sjögren’s syndrome by relating ultrasonography severity scores to clinical and laboratory data.

Methods

Seventy patients who fulfilled the 2002 American-European Consensus Group diagnostic criteria for primary Sjögren’s syndrome were selected from 84 patients receiving care in specialized outpatient clinics at our institution from November 2013 to May 2016. Their serology, European League Against Rheumatism Sjögren’s syndrome disease activity index (ESSDAI), salivary flow rate, immunoglobulin G, and salivary and serum beta-2 microglobulin levels were measured. Salivary gland ultrasonography was performed by an experienced radiologist, using scores of 1–4 to classify salivary gland impairment.

Results

Salivary gland ultrasonography scores of 1 or 2 were associated with an ESSDAI < 5. Ultrasonography scores of 3 or 4 were associated with an ESSDAI ≥5 (p = 0.064), a positive antinuclear antibody test (p = 0.006), positive anti-Ro/SSA antibodies (p = 0.003), positive anti-La/SSB antibodies (p = 0.077), positive rheumatoid factor (p = 0.034), and immunoglobulin G levels > 1600 mg/dL (p = 0.077). Salivary flow rate was lower in patients with scores 3 or 4 (p = 0.001).

Conclusion

This study provides further evidence that salivary gland ultrasonography can be used not only for diagnosis but also for prognostic evaluation of primary Sjögren’s syndrome. These findings confirm what has been reported in the literature. However, further analyses involving larger matched samples are required to support this finding and include salivary gland ultrasonography as part of the diagnostic criteria for Sjögren’s syndrome.

Serum 25-Hydroxyvitamin D3 and BAFF Levels Are Associated with Disease Activity in Primary Sjogren's Syndrome

The study investigated the association between disease activity and serum 25-hydroxyvitamin D3 (25(OH)-D3), B cell activation of the tumor necrosis factor family (BAFF), or β₂ microglobulin in patients with primary Sjogren's syndrome (SS). Sixty-nine primary SS patients and 22 sicca control patients were included in the study. Disease activity was measured with EULAR Sjogren's syndrome disease activity index (ESSDAI). Serum levels of 25(OH)-D3 and β₂ microglobulin were measured by radioimmunoassay and BAFF was measured by an enzyme-linked immunosorbent assay. Serum levels of 25(OH)-D3 were significantly lower in SS patients compared to the sicca controls (p = 0.036). Serum levels of BAFF tended to be higher (p = 0.225) and those of β₂ microglobulin were significantly higher in patients with SS than in sicca controls (p = 0.023). In univariate regression analyses, ESSDAI was significantly associated with serum levels of 25(OH)-D3, BAFF, and β₂ microglobulin. After stepwise backward multivariate linear regression analyses including age and acute phase reactants, ESSDAI was associated with 25(OH)-D3 (β = −0.042, p = 0.015) and BAFF (β = 0.001, p = 0.015) in SS patients. In SS patients, ESSDAI is negatively associated with serum levels of 25(OH)-D3 and positively associated with BAFF.

New biological therapies in Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by dryness and systemic involvement in more than a third of the patients. Patient management has suffered from the lack of effective treatments. However, progresses made in the understanding of pSS pathogenesis have allowed a move to a more targeted approach to therapeutic intervention. Given the key role of chronic B cell activation, B cell-targeted therapies were the first candidate. New pathways are currently investigated including costimulation and ectopic germinal centre formation. In this review, we have summarized the new tools available in clinical research in the field of pSS, the current evidence regarding B cell-targeted therapies and an overview of the promising drugs in the pipeline.

Development of the ClinESSDAI: a clinical score without biological domain. A tool for biological studies

Objective

To develop and validate ClinESSDAI (Clinical European League Against Rheumatism Sjögren's Syndrome Disease Activity Index), ie, ESSDAI without the biological domain.

Patients and methods

The 702 fictive vignettes derived from 96 real cases of primary Sjögren's syndrome of the ESSDAI development study were used. As for ESSDAI development, the physician assessment of disease activity (0–10 scale) was used as the ‘gold standard’ in a multivariate model for weighting domains, after removing the biological domain. The reliability, assessed by intraclass correlation coefficient (ICC) between ClinESSDAI and ESSDAI, explored if ClinESSDAI was equivalent to ESSDAI. Its psychometric (ie, measurement) properties were compared with that of ESSDAI in an independent cohort. Also, its use was evaluated on data of two clinical trials.

Results

In multivariate modelling, all 11 domains remained significantly associated with disease activity, with slight modifications of some domain weights. Reliability between clinESSDAI and ESSDAI was excellent (ICC=0.98 and 0.99). Psychometric properties of clinESSDAI, disease activity levels and minimal clinically important improvement thresholds and its ability to detect change over time in clinical trials were very close to that of ESSDAI.

Conclusions

ClinESSDAI appears valid and very close to the original ESSDAI. This score provides an accurate evaluation of disease activity independent of B-cell biomarkers. It could be used in various circumstances: (i) in biological/clinical studies to avoid data collinearity, (ii) in clinical trials, as secondary endpoint, to detect change independent of biological effect of the drug, (iii) in clinical practice to assess disease activity for visits where immunological tests have not been done.

EULAR Sjögren's syndrome disease activity index (ESSDAI): a user guide

The EULAR Sjögren's syndrome (SS) disease activity index (ESSDAI) is a systemic disease activity index that was designed to measure disease activity in patients with primary SS. With the growing use of the ESSDAI, some domains appear to be more challenging to rate than others. The ESSDAI is now in use as a gold standard to measure disease activity in clinical studies, and as an outcome measure, even a primary outcome measure, in current randomised clinical trials. Therefore, ensuring an accurate and reproducible rating of each domain, by providing a more detailed definition of each domain, has emerged as an urgent need. The purpose of the present article is to provide a user guide for the ESSDAI. This guide provides definitions and precisions on the rating of each domain. It also includes some minor improvement of the score to integrate advance in knowledge of disease manifestations. This user guide may help clinicians to use the ESSDAI, and increase the reliability of rating and consequently of the ability to detect true changes over time. This better appraisal of ESSDAI items, along with the recent definition of disease activity levels and minimal clinically important change, will improve the assessment of patients with primary SS and facilitate the demonstration of effectiveness of treatment for patients with primary SS.

ESSPRI and other patient-reported indices in patients with primary Sjogren's syndrome during 100 consecutive outpatient visits at one rheumatological clinic

OBJECTIVE

A European League Against Rheumatism (EULAR) SS disease activity index (ESSDAI) and a patient-reported index (ESSPRI) have recently been developed and validated. In our previous study the ESSDAI correlated significantly with serum β2 microglobulin concentration. We now aim to establish whether the ESSPRI is also associated with serum β2 microglobulin or with other patient-reported indices.

METHODS

The data on 100 consecutive visits of patients with primary SS (pSS) were reviewed from the patient charts. Patients who had filled out the ESSPRI questionnaire and fulfilled at least four of the revised American-European consensus group criteria for pSS were included. Data were gathered on the ESSPRI (0-10 cm) and on the patient's global health assessment [visual analogue scale (VAS) 0-10 cm] (PGH-VAS), pain-VAS (0-10 cm) and HAQ (range 0-3).

RESULTS

The ESSPRI correlated significantly with the PGH-VAS (r = 0.753, P < 0.0001), pain-VAS (r = 0.656, P < 0.0001) and HAQ (r = 0.542, P < 0.0001) (Spearman's correlation). It also correlated weakly with serum β2 microglobulin (r = 0.214, P = 0.043) and ESR levels (r = 0.235, P = 0.019).

CONCLUSION

The ESSPRI correlated significantly with other patient-reported indices, serum β2 microglobulin and ESR in patients with pSS. Our results support the view that the ESSPRI is a useful tool in the follow-up of patients with pSS.

Serum levels of beta2-microglobulin and free light chains of immunoglobulins are associated with systemic disease activity in primary Sjögren's syndrome. Data at enrollment in the prospective ASSESS cohort

Objectives

To analyze the clinical and immunological characteristics at enrollment in a large prospective cohort of patients with primary Sjögren's syndrome (pSS) and to investigate the association between serum BAFF, beta2-microglobulin and free light chains of immunoglobulins and systemic disease activity at enrollment.

Methods

Three hundred and ninety five patients with pSS according to American-European Consensus Criteria were included from fifteen centers of Rheumatology and Internal Medicine in the “Assessment of Systemic Signs and Evolution of Sjögren's Syndrome” (ASSESS) 5-year prospective cohort. At enrollment, serum markers were assessed as well as activity of the disease measured with the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI).

Results

Patient median age was 58 (25^th–75^th: 51–67) and median disease duration was 5 (2–9) years. Median ESSDAI at enrollment was 2 (0–7) with 30.9% of patients having features of systemic involvement. Patients with elevated BAFF, beta2-microglobulin and kappa, lambda FLCS had higher ESSDAI scores at enrollment (4 [2]–[11] vs 2 [0–7], P = 0.03; 4 [1]–[11] vs 2 [0–7], P< 0.0001); 4 [2]–[10] vs 2 [0–6.6], P< 0.0001 and 4 [2–8.2] vs 2 [0–7.0], P = 0.02, respectively). In multivariate analysis, increased beta2-microglobulin, kappa and lambda FLCs were associated with a higher ESSDAI score. Median BAFF and beta2-microglobulin were higher in the 16 patients with history of lymphoma (1173.3(873.1–3665.5) vs 898.9 (715.9–1187.2) pg/ml, P = 0.01 and 2.6 (2.2–2.9) vs 2.1 (1.8–2.6) mg/l, P = 0.04, respectively).

Conclusion

In pSS, higher levels of beta2-microglobulin and free light chains of immunoglobulins are associated with increased systemic disease activity.