Diagnostic and predictive value of anti-cyclic citrullinated protein antibodies in rheumatoid arthritis: a systematic literature review

Drug Survival on First Biologic Therapy Among Late-Onset Rheumatoid Arthritis Patients Compared to Early-Onset Patients: A Population-Based Cohort Study

INTRODUCTION

Rheumatoid arthritis (RA) patients can be divided according to the age of disease onset and classified as late-onset RA ≥ 60 years old or early-onset RA < 60 years old. Current treatment guidelines do not stipulate any preference regarding the biologic that should be used first in the late-onset group. This study aims to compare the drug survival times on first biological treatment between late and early-onset RA patients.

METHODS

This is a population based cohort study using the medical records of Leumit healthcare services. We included all eligible RA patients between 2000 and 2017. RA patients were divided into late- and early-onset RA groups and compared according to drug survival time on the first biological therapy.

RESULTS

The final cohort included 3814 RA patients, 2807 (73.6%) of whom had early-onset RA. Overall, biologic disease-modifying anti-rheumatic drugs (bDMARDs) were used more often among early-onset compared to late-onset patients (16.9% vs. 7.8%, p < 0.001). Among early-onset patients, etanercept was associated with the longest drug survival time on the first biologic, and adalimumab and infliximab were associated with the longest drug survival times among late-onset patients. No differences were observed in drug survival times between late and early-onset patients on the first bDMARD, except for abatacept and golimumab with longer drug survival time among early-onset patients.

CONCLUSION

Late-onset RA patients were treated with biologics to a lesser extent than early-onset patients, but no differences were observed in drug survival times at the first bDMARD between the two groups.

Microbiota-Derived Extracellular Vesicle as Emerging Actors in Host Interactions

The human microbiota is an intricate micro-ecosystem comprising a diverse range of dynamic microbial populations mainly consisting of bacteria, whose interactions with hosts strongly affect several physiological and pathological processes. The gut microbiota is being increasingly recognized as a critical player in maintaining homeostasis, contributing to the main functions of the intestine and distal organs such as the brain. However, gut dysbiosis, characterized by composition and function alterations of microbiota with intestinal barrier dysfunction has been linked to the development and progression of several pathologies, including intestinal inflammatory diseases, systemic autoimmune diseases, such as rheumatic arthritis, and neurodegenerative diseases, such as Alzheimer's disease. Moreover, oral microbiota research has gained significant interest in recent years due to its potential impact on overall health. Emerging evidence on the role of microbiota-host interactions in health and disease has triggered a marked interest on the functional role of bacterial extracellular vesicles (BEVs) as mediators of inter-kingdom communication. Accumulating evidence reveals that BEVs mediate host interactions by transporting and delivering into host cells effector molecules that modulate host signaling pathways and cell processes, influencing health and disease. This review discusses the critical role of BEVs from the gut, lung, skin and oral cavity in the epithelium, immune system, and CNS interactions.

Associations of Rheumatoid Factor, Rheumatoid Arthritis, and Interleukin-6 Inhibitor with the Prognosis of Ischemic Stroke: a Prospective Multicenter Cohort Study and Mendelian Randomization Analysis

Rheumatoid factor (RF), an established diagnostic biomarker for rheumatoid arthritis (RA), is associated with cardiovascular diseases, but its impact on clinical outcomes of ischemic stroke remains unclear. We aimed to investigate the observational associations between serum RF and prognosis of ischemic stroke, and further examined the genetic associations of RA and its therapeutic strategy, interleukin-6 (IL-6) inhibitor, with prognosis of ischemic stroke. We measured serum RF levels in 3474 Chinese ischemic stroke patients from the China Antihypertensive Trial in Acute Ischemic Stroke. The primary outcome was the composite outcome of death or major disability (modified Rankin Scale score ≥3) at 3 months after stroke onset. Mendelian randomization (MR) analyses were performed to examine the associations of genetically predicted RA and IL-6 inhibition with prognosis of ischemic stroke. During 3 months of follow-up, 866 patients (25.43%) experienced death or major disability. After multivariate adjustment, RF-positive was significantly associated with a high risk of primary outcome (OR, 1.47; 95% CI, 1.08-2.00; P =0.016) compared with RF-negative. The two-sample MR analyses suggested that genetically predicted RA was associated with an increased risk of primary outcome (OR, 1.09; 95% CI, 1.01-1.18; P=0.021), while genetically predicted IL-6 inhibition was associated with a decreased risk of primary outcome (OR, 0.88; 95% CI, 0.77-0.99; P=0.041). We found that positive RF was associated with increased risks of adverse outcomes after atherosclerotic ischemic stroke, and genetically predicted RA and IL-6 inhibition increased and decreased the risks of adverse outcomes after ischemic stroke, respectively.

Inflammatory Arthritis in Systemic Sclerosis: Its Epidemiology, Associations, and Morbidity

OBJECTIVE

To describe the epidemiology, associations, and impact of inflammatory arthritis (IA) in systemic sclerosis (SSc).

METHODS

Patients with SSc prospectively enrolled in the Australian Scleroderma Cohort Study were included. IA was defined clinically as the presence of synovitis on examination. Logistic regression was used to determine the associations of IA with SSc manifestations and serological parameters. Patient-reported outcome measures were used to capture physical function and health-related quality of life (HRQoL).

RESULTS

IA was a common SSc manifestation affecting one-third (33.3%) of patients over a median follow-up of 4.3 (1.7-8.4) years. Associations of IA included diffuse SSc (odds ratio [OR] 1.33, 95% confidence interval [95% CI] 1.01-1.74, P = 0.042), concurrent musculoskeletal manifestations (joint contractures and tendon friction rubs, OR 1.70, 95% CI 1.34-2.15, P < 0.001); myositis (OR 2.11, 95% CI 1.39-3.20, P < 0.001), and sicca symptoms (OR 1.57, 95% CI 1.14-2.16, P = 0.006), whereas IA was negatively associated with pulmonary arterial hypertension (OR 0.52, 95% CI 0.35-0.78, P = 0.002). Neither the presence of rheumatoid factor nor U1 small nuclear RNP were associated with IA (OR 1.13, 95% CI 0.88-1.44, P = 0.331, OR 1.46, 95% CI 0.89-2.39, P = 0.129 respectively). Positive anticyclic citrullinated protein antibodies, although at low frequency, were more common in those with IA compared with those without IA (7.5% vs 1.5%, P < 0.001). IA was associated with significantly lower HRQoL score (P < 0.001) and more physical disability than in those without IA (P < 0.001).

CONCLUSION

IA is a common disease manifestation that is more frquently seen in diffuse disease. IA is associated with poor HRQoL and physical disability. Further research is needed into the effective management of IA in SSc.

Identification of autoantibodies against PsoP27 in synovial fluid derived from psoriatic arthritis and rheumatoid arthritis patients

PsoP27 is an antigen expressed in psoriatic lesions. It plays an inflammatory role in psoriasis. This study objective was to characterize antibodies (Abs) against PsoP27 in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA). Levels of Abs against native and citrullinated PsoP27 in PsA and RA patients' synovial fluid (SF) and sera were determined by ELISA. SF of osteoarthritis (OA) patients and sera of healthy donors were used as controls. Levels of Abs against PsoP27 were correlated with disease activity scores. Abs against native and citrullinated PsoP27 levels in SF of PsA (n = 48; 0.38 ± 0.03 and 0.44 ± 0.04, respectively) and RA (n = 22; 0.57 ± 0.1 and 0.62 ± 0.09, respectively) were significantly higher than in OA patients (n = 23; 0.14 ± 0.01 and 0.15 ± 0.01, respectively) (p < .0001). For both Abs, there were no significant differences between their level in PsA and RA patients. There was no difference in the level of Abs against citrullinated PsoP27 in SF of seronegative versus seropositive RA patients. Levels of Abs against both native and citrullinated PsoP27 in the SF and level of systemic C-reactive protein in PsA correlated positively, while in RA there were no significant correlations with disease activity scores. No differences in level of Abs against PsoP27 were found in the sera of all three study groups. Abs against native and citrullinated PsoP27 are present in PsA and RA SF but not in those of OA patients, suggesting a potential role of those Abs in inflammatory joint diseases.

A statistical symptomatic evaluation on SAPHO syndrome from 56 cases of confirmed diagnosis and 352 cases of non-SAPHO involvement

OBJECTIVE

To report a statistical evaluation of symptomatology based on 56 cases of SAPHO syndrome and 352 non-SAPHO involvement cases, to propose a symptomatic scoring system in consideration of early warning for SAPHO syndrome.

METHODS

A cohort comprising 56 subjects diagnosed with SAPHO syndrome was reported, as well as 352 non-SAPHO involvement cases, including their chief complaints, skin manifestations, radiological findings, and laboratory tests. We systematically reviewed previous published five representative huge cohorts from different countries to conclude several specific features of SAPHO by comparing with our case series. The score of each specific index is based on respective incidence and comparison of two cohorts was performed.

RESULT

In terms of complaint rates, all subjects of two cohorts suffered from osseous pain, which appeared in the anterior chest wall, spine, and limb which were calculated. In respect to dermatological lesions, SAPHO patients suffered from severe acne, and other patients (82.14%) accompanied with palmoplantar pustulosis. Having received radiological examinations, most SAPHO subjects rather than non-SAPHO involvement cases showed abnormal osteoarticular lesions under CT scanning and more detailed information under whole-body bone scintigraphy. Differences also emerged in elevation of inflammation values and rheumatic markers like HLA-B27. Based on our cases and huge cohorts documented, the early warning standard is set to be 5 scores.

CONCLUSIONS

SAPHO syndrome case series with 56 subjects were reported and an accumulative scoring system for the early reminder on SAPHO syndrome was proposed. The threshold of this system is set to be 5 points. Key Points • Fifty-six patients diagnosed by SAPHO syndrome with detailed symptoms and radiological findings were reported. • Comparison was made between the 56 SAPHO patients and 352 non-SAPHO involvement cases. • An accumulative scoring system for the early reminder on SAPHO syndrome was proposed and the threshold of this system is set to be five points.

Soluble signal inhibitory receptor on leukocytes-1 reflects disease activity and assists diagnosis of patients with rheumatoid arthritis

BACKGROUND

SIRL-1, an immunosuppressive receptor encoded by the VSTM1 gene, has recently been linked to rheumatoid arthritis (RA) due to its association with activated polymorphonuclear neutrophils (PMNs). Considering that the activated PMNs play a crucial role in the pathogenesis of rheumatoid arthritis (RA), we aimed to measure the levels of soluble SIRL-1, investigating whether they add value to RA in the clinical diagnosis.

METHODS

Utilizing an enzyme-linked immunosorbent assay, the concentration of sSIRL-1 was measured in serum samples from cohort 1 diagnosed with RA (n = 96), gout (n = 54), osteoarthritis (n = 47), healthy controls (n = 86) and synovial fluid samples from OA (n = 8) and RA (n = 8) patients, respectively. Additionally, an external validation in cohort 2 (n = 156) comprising various inflammatory diseases was employed.

RESULTS

The study revealed a distinctive upregulation of sSIRL-1 in the serum of RA compared to HC and other arthralgia diseases (p < 0.0001), which also displayed a significant elevation in synovial fluid from RA compared to OA (p < 0.05). Notably, sSIRL-1 levels exhibited a significant decrease in patients who achieved disease remission (p < 0.05). Furthermore, the diagnostic accuracy of RA was enhanced when sSIRL-1 was combined with anti-CCP and RF, yielding an impressive AUC value of 0.950.

CONCLUSION

The expression pattern of sSIRL-1 in RA, coupled with its correlation with disease activity, underscores its potential clinical utility for both diagnosis and disease monitoring in RA patients. This study offers valuable insights into the evolving diagnostic landscape of RA.

Are the cut-offs of the rheumatoid factor and anti-cyclic citrullinated peptide antibody different to distinguish rheumatoid arthritis from their primary differential diagnoses?

OBJECTIVE

Rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (anti-CCP) are commonly used for diagnosis of rheumatoid arthritis (RA), although other rheumatic diseases with arthritis can test positive. This study aimed to determine the cutoff values for RF and anti-CCP with the best diagnostic performance in a sample of patients with RA, compared with other rheumatic diseases.

METHODS

This was a descriptive, prospective study. EUROINMMUN enzyme-linked immunosorbent assays for RF isotypes immunoglobulin (Ig) A (IgA), IgG and IgM and third-generation assay IgG for anti-CCP were used in serum samples of patients with RA, other rheumatic diseases and healthy subjects. The cutoff with the best diagnostic performance was determined by the Youden Index and receiver operating characteristic analysis Results: Three hundred and thirty-two serum samples were analysed. The cutoffs proposed in our population were for RF in RA patients versus other rheumatic diseases, and healthy subjects IgM 135 IU/mL, for each disease, compared with RA, were psoriatic arthritis (Psa) IgA 47.2 IU/mL, clinically suspicious arthralgia (CSA) IgA 39.5 IU/mL, primary Sjögren's syndrome (pSS) IgM 180.6 IU/mL, systemic lupus erythematosus (SLE) IgA 42.6 IU/mL, primary fibromyalgia (pFM) IgM 68.6 IU/mL, osteoarthritis (OA) IgM 48 IU/mL, gout IgM 117 IU/mL and healthy IgM 16.3 IU/mL. For anti-CCP, in RA patients versus other rheumatic diseases, and healthy subjects 6.95 IU/mL, for each disease, compared with RA, were Psa 6.8 IU/mL, CSA 9.95 IU/mL, pSS 20.7 IU/mL, SLE 6 IU /mL, pFM 11.8 IU/mL, OA 11.9 IU/mL, gout 5 IU/mL and healthy 5 IU/mL.

CONCLUSION

Irrespective of the manufacturer's suggested cutoff, the RA versus differential diagnosis cutoffs must be considered.

[Diurnal differences in acute gout attacks: A clinical study of male gout patients]

OBJECTIVE

To observe the diurnal difference of acute gout attacks in men, and provide reference for accurate clinical prevention and treatment.

METHODS

Using a single-center, cross-sectional study design, the patients diagnosed with gout in the outpatient department of Rheumatology and Immuno-logy of PLA Joint Logistic Support Force No.980 Hospital from October 2021 to April 2022 were selected. The information about the patient's current/last acute gout attacks (less than 2 weeks from visit), date and time of attacks, joint symptoms and signs, medication use, and relevant biochemical tests on the day of visit was recorded. The diurnal time difference of acute gout attacks in male patients was analyzed, and univariate comparison and multivariate Logistic regression analyses were conducted to compare the diurnal difference of acute gout attacks with clinical characteristics and biochemical indicators.

RESULTS

A total of 100 male gout patients were included, and 100 acute attacks were recorded. Diurnal distribution of acute gout attacks: morning (6:00~11:59, 18, 18%), afternoon (12:00~17:59, 11, 11%), the first half of the night (18:00~23:59, 22, 22%), the second half of the night (0:00~05:59, 49, 49%); During the day (included morning and afternoon, 29, 29%) and at night (included the first half of the night and the second half of the night, 71, 71%). The rate of acute gout attack was significantly higher at night than in the day (about 2.5 ∶1). No matter the first or recurrent gout, no matter the duration of the disease, the number of acute gout attacks had the difference of less in the day and more in the night. Serum urate (SU) level was higher in the patients with nocturnal attack than in those with daytime attack (P=0.044). Comorbidities were significantly different in the day-night ratio of the number of acute gout attack (P=0.028). Multiple Logistic regression analysis showed that SU level (OR=1.005, 95%CI: 1.001-1.009) and comorbidities (OR=3.812, 95%CI: 1.443-10.144) were the correlative factors of nocturnal acute gout attacks.

CONCLUSION

No matter the first or recurrent gout, no matter the duration of the disease, it has a diurnal variation characterized by multiple attacks at night, increased SU level and comorbidities are correlative factors for nocturnal acute attack of gout.

Treatable Traits in Systemic Sclerosis

Systemic sclerosis (SSc) is a chronic systemic disease within the spectrum of connective tissue diseases, specifically characterized by vascular abnormalities and inflammatory and fibrotic involvement of the skin and internal organs resulting in high morbidity and mortality. The clinical phenotype of SSc is heterogeneous, and serum autoantibodies together with the extent of skin involvement have a predictive value in the risk stratification. Current recommendations include an organ-based management according to the predominant involvement with only limited individual factors included in the treatment algorithm. Similar to what has been proposed for other chronic diseases, we hypothesize that a "treatable trait" approach based on relevant phenotypes and endotypes could address the unmet needs in SSc stratification and treatment to maximize the outcomes. We provide herein a comprehensive review and a critical discussion of the literature regarding potential treatable traits in SSc, focusing on established and candidate biomarkers, with the purpose of setting the bases for a precision medicine-based approach. The discussion, structured based on the organ involvement, allows to conjugate the pathogenetic mechanisms of tissue injury with the proposed predictors, particularly autoantibodies and other serum biomarkers. Ultimately, we are convinced that precision medicine is the ideal guide to manage a complex condition such as SSc for which available treatments are largely unsatisfactory.

Exploration of the association between the single-nucleotide polymorphism of co-stimulatory system and rheumatoid arthritis

Introduction

The human leukocyte antigen (HLA) has been linked to the majority of autoimmune diseases (ADs). However, non-HLA genes may be risk factors for ADs. A number of genes encoding proteins involved in regulating T-cell and B-cell function have been identified as rheumatoid arthritis (RA) susceptibility genes.

Methods

In this study, we investigated the association between RA and single-nucleotide polymorphisms (SNPs) of co-stimulatory or co-inhibitory molecules in 124 RA cases and 100 healthy controls without immune-related diseases [including tumor necrosis factor superfamily member 4 (TNFSF4), CD28, cytotoxic T-lymphocyte-associated protein 4 (CTLA4), and programmed cell death protein 1 (PDCD1)].

Results

The results showed that there were 13 SNPs associated with RA, including rs181758110 of TNFSF4 (CC vs. CT, p = 0.038); rs3181096 of CD28 (TT vs. CC + CT, p = 0.035; CC vs. TT, p = 0.047); rs11571315 (TT vs. CT, p = 0.045), rs733618 (CC vs. TT + CT, p = 0.043), rs4553808 (AA vs. AG vs. GG, p = 0.035), rs11571316 (GG vs. AG vs. AA, p = 0.048; GG vs. AG + AA, p = 0.026; GG vs. AG, p = 0.014), rs16840252 (CC vs. CT vs. TT, p = 0.007; CC vs. CT, p = 0.011), rs5742909 (CC vs. CT vs. TT, p = 0.040), and rs11571319 of CTLA4 (GG vs. AG vs. AA, p < 0.001; GG vs. AG + AA, p = 0.048; AA vs. GG + AG, p = 0.001; GG vs. AA, p = 0.008; GG vs. AG, p ≤ 0.001); and rs10204525 (TT vs. CT + CC, p = 0.024; TT vs. CT, p = 0.021), rs2227982 (AA vs. GG, p = 0.047), rs36084323 (TT vs. CT vs. CC, p = 0.022; TT vs. CT + CC, p = 0.013; CC vs. TT + CT, p = 0.048; TT vs. CC, p = 0.008), and rs5839828 of PDCD1 (DEL vs. DEL/G vs. GG, p = 0.014; DEL vs. DEL/G + GG, p = 0.014; GG vs. DEL + DEL/G, p = 0.025; DEL vs. GG, p = 0.007).

Discussion

Consequently, these SNPs may play an important role in immune regulation, and further research into the role of these SNPs of immune regulatory genes in the pathogenesis of RA is required.

Hands and feet radiologic involvements in systemic sclerosis

AIM

Systemic sclerosis (SSc) is a rare autoimmune disorder characterized by vascular and fibrosing involvement of the skin and internal organs. In this study, we determined the prevalence and characteristics of radiological hands and feet involvements in Iranian SSc patients to identify the associations between clinical features and radiologic findings.

METHODS

43 SSc patients (41 women and 2 men), with a median age of 44.8 years (ranges 26-70 years) and a mean disease duration of 11.8 years (ranges 2-28 years) were studied in this cross-sectional study.

RESULTS

42 patients had radiological changes both in their hands and feet. Only one patient had alteration just in hand. The most frequent changes that we found in hand were Juxta-articular Osteoporosis (93%), Acro-osteolysis (58.2%), and Joint Space Narrowing (55.8%). The prevalence of joint space narrowing or acro-osteolysis was higher in subjects with active skin involvement [modified Rodnan skin score (mRSS) > 14] [16/21 vs. 4/16 for patients with inactive skin involvement (mRSS < 14); p = 0.002]. The most frequent changes that we found in the foot were Juxta-articular Osteoporosis (93%), Acro-osteolysis (46.5%), Joint Space Narrowing (58.1%), and subluxation (44.2%). The presence of anti-ccp antibody was detected in 4 (9.3%), while positive rheumatoid factor was found in 13 (30.2%) of SSc patients.

CONCLUSION

This study corroborates that arthropathy is common in SSc patients. The introduction of the specific radiological involvements of SSc needs to be confirmed by further studies, in order to define the appropriate prognosis and treatment of patients.

Bacterial extracellular vesicles and their interplay with the immune system

The mammalian intestinal tract harbors trillions of microorganisms confined within this space by mucosal barriers. Despite these barriers, bacterial components may still be found elsewhere in the body, even in healthy subjects. Bacteria can release small lipid-bound particles, also named bacterial extracellular vesicles (bEV). While bacteria themselves cannot normally penetrate the mucosal defense, bEVs may infiltrate the barrier and disseminate throughout the body. The extremely diverse cargo that bEVs can carry, depending on their parent species, strain, and growth conditions, grant them an equally broad potential to interact with host cells and influence immune functions. Herein, we review the current knowledge of processes underlying the uptake of bEVs by mammalian cells, and their effect on the immune system. Furthermore, we discuss how bEVs could be targeted and manipulated for diverse therapeutic purposes.

Nanomedical approaches in the realm of rheumatoid arthritis

Rheumatoid arthritis (RA) is a heterogeneous autoimmune inflammatory disorder defined by the damage to the bone and cartilage in the synovium, which causes joint impairment and an increase in the mortality rate. It is associated with an incompletely elucidated pathophysiological mechanism. Even though disease-modifying antirheumatic drugs have contributed to recent improvements in the standard of care for RA, only a small fraction of patients is able to attain and maintain clinical remission without the necessity for ongoing immunosuppressive drugs. The evolution of tolerance over time as well as patients' inability to respond to currently available therapy can alter the overall management of RA. A significant increase in the research of RA nano therapies due to the possible improvements they may provide over traditional systemic treatments has been observed. New approaches to getting beyond the drawbacks of existing treatments are presented by advancements in the research of nanotherapeutic techniques, particularly drug delivery nano systems. Via passive or active targeting of systemic delivery, therapeutic drugs can be precisely transported to and concentrated in the affected sites. As a result, nanoscale drug delivery systems improve the solubility and bioavailability of certain drugs and reduce dose escalation. In the present paper, we provide a thorough overview of the possible biomedical applications of various nanostructures in the diagnostic and therapeutic management of RA, derived from the shortcomings of conventional therapies. Moreover, the paper suggests the need for improvement on the basis of research directions and properly designed clinical studies.

Patients with seronegative rheumatoid arthritis have a different phenotype than seropositive patients: A clinical and ultrasound study

Introduction

Rheumatoid arthritis (RA) is an inflammatory disease whose clinical phenotype largely depends on the presence of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). Seronegative RA appears to be a less severe disease, but this remains controversial. This study aimed to assess whether seronegative patients show a less severe disease than seropositive patients.

Methods

A cross-sectional study was conducted on RA outpatients from a single center. Clinical activity scales, laboratory evaluations, and cardiovascular risk scores were assessed. Musculoskeletal ultrasound (US) examinations were performed.

Results

One hundred and fourteen patients were enrolled. Eighty-five were seropositive (76% women) and 29 seronegative (93% women). Seropositive patients had a younger age at disease onset (43 ± 14 vs. 54 ± 11; p = 0.001) and used sulfasalazine (47 vs. 17%; p = 0.004) and glucocorticoids (36 vs. 10%; p = 0.007) more frequently. No differences in clinical activity scales and in 10-year cardiovascular risk were observed. Pathological US data were found more frequently in seropositive patients in the 2^nd metacarpophalangeal (MCP) joint, both in grayscale (71 vs. 38%; p = 0.008) and in power Doppler (PD; 53 vs. 9%; p < 0.001); erosions (36 vs. 9%; p = 0.020) were also more frequent. We found greater severity of PD signals in the 2nd MCP and 3rd MCP joints of the seropositive patients, while synovitis severity was higher only in the 2nd MCP joints. The percentage of total joints with erosions (9 vs. 1%; p < 0.001) and 2nd MCP joints with erosions (25 vs. 7%; p < 0.001) was higher in seropositive patients.

Conclusion

RA patients show a differentiated phenotype according to their ACPA and RF status. In seronegative patients, RA begins later in life and has a lower requirement for antirheumatic therapies. On US evaluation, seropositive patients show more joint damage, especially in MCP joints. Despite this, long-term cardiovascular risk is similar among RA patients, regardless of their RF and ACPA status.

Lung function data of North-African patients with rheumatoid arthritis: a comparative study between anti-citrullinated peptides antibodies positive and negative patients

INTRODUCTION

Although lung damages are among the leading causes of death from Rheumatoid Arthritis (RA), few studies have assessed the spirometric and plethysmographic data and profile of patients with RA, particularly those with Anti-Citrullinated Peptides Antibodies Positive (ACPA+).

AIM

To compare the spirometric and plethysmographic data and profile of RA patients ACPA+ and ACPA-.

METHODS

This comparative pilot study was performed over a two-year period (2018-2019) in Algiers (Algeria). The study included two groups of RA non-smoker patients: 26 ACPA+ and 33 ACPA-.RA was diagnosed according to the ACR/EULAR 2010 RA classification criteria. Spirometry and plethysmography were performed. The following definitions were applied: Obstructive Ventilatory Impairment (OVI): FEV1/FVC z-score < -1.645; Restrictive Ventilatory Impairment (RVI): Total Lung Capacity (TLC) z-score< -1.645; Mixed Ventilatory Impairment (MVI): FEV1/FVC z-score < -1.645 and TLC z-score < -1.645; lung- hyperinflation: residual volume z-score > +1.645; Nonspecific Ventilatory Impairment (NSVI): FEV1z-score < -1.645, FVC z-score < -1.645, FEV1 /FVC z-score ≥ -1.645, and TLC z-score ≥ -1.645.

RESULTS

The ACPA-group was older than the ACPA+ one by ~ 10 years (63±13 vs. 53±12 years, p=0.0025; respectively). The ACPA+ and ACPA-groups included comparative percentages of patients having RVI, MVI, and NSVI (23.1 vs. 45.5%, p=0.0745; 3.8 vs. 3.0%, p=0.8654; and 7.7 vs. 6.1%, p=0.8086; respectively). Compared to the ACPA- group, the ACPA+ group included a higher percentage of patients having OVI and lung-hyperinflation (9.1 vs. 38.5%, p=0.0069; 9.1 vs. 42.3%, p=0.0029; respectively).

CONCLUSION

Compared to the ACPA-group, the ACPA+ one had more lung-hyperinflation and OVI, and comparative percentages of RVI, MVI, and NSVI.

Prediction of Immune-Related Adverse Events Induced by Immune Checkpoint Inhibitors With a Panel of Autoantibodies: Protocol of a Multicenter, Prospective, Observational Cohort Study

Introduction: Immune checkpoint inhibitor (ICI) therapy is markedly improving the prognosis of patients with several types of cancer. On the other hand, the growth in the use of these drugs in oncology is associated with an increase in multiple immune-related adverse events (irAEs), whose optimal prevention and management remain unclear. In this context, there is a need for reliable and validated biomarkers to predict the occurrence of irAEs in patients treated with ICIs. Thus, the main objective of this study is to evaluate the diagnostic performance of a sensitive routinely available panel of autoantibodies consisting of antinuclear antibodies, rheumatoid factor, and antineutrophil cytoplasmic antibodies to identify patients at risk of developing irAEs.

Methods and Analysis: A multicenter, prospective, observational, cohort study has been designed to be conducted in patients diagnosed with cancer amenable to ICI therapy. Considering the percentage of ICI-induced irAEs to be 25% and a loss to follow-up of 5%, it has been estimated that a sample size of 294 patients is required to detect an expected sensitivity of the autoantibody panel under study of 0.90 with a confidence interval (95%) of no less than 0.75. For 48 weeks, patients will be monitored through the oncology outpatient clinics of five hospitals in Spain. Immune-related adverse events will be defined and categorized according to CTCAE v. 5.0. All the patients will undergo ordinary blood tests at specific moments predefined per protocol and extraordinary blood tests at the time of any irAE being detected. Ordinary and extraordinary samples will be frozen and stored in the biobank until analysis in the same autoimmunity laboratory when the whole cohort reaches week 48. A predictive model of irAEs will be constructed with potential risk factors of immune-related toxicity including the autoantibody panel under study.

Ethics and Dissemination: This protocol was reviewed and approved by the Ethical Committee of the Basque Country and the Spanish Agency of Medicines and Medical Devices. Informed consent will be obtained from all participants before their enrollment. The authors declare that the results will be submitted to an international peer-reviewed journal for their prompt dissemination.

Prediction of diagnosis results of rheumatoid arthritis patients based on autoantibodies and cost-sensitive neural network

OBJECTIVES

To analyze and evaluate the effectiveness of the detection of single autoantibody and combined autoantibodies in patients with rheumatoid arthritis (RA) and related autoimmune diseases and establish a machine learning model to predict the disease of RA.

METHODS

A total of 309 patients with joint pain as the first symptom were retrieved from the database. The effectiveness of single and combined antibodies tests was analyzed and evaluated in patients with RA, a cost-sensitive neural network (CSNN) model was used to integrate multiple autoantibodies and patient symptoms to predict the diagnosis of RA, and the ROC curve was used to analyze the diagnosis performance and calculate the optimal cutoff value.

RESULTS

There are differences in the seropositive rate of autoimmune diseases, the sensitivity and specificity of single or multiple autoantibody tests were insufficient, and anti-CCP performed best in RA diagnosis and had high diagnostic value. The cost-sensitive neural network prediction model had a sensitivity of up to 0.90 and specificity of up to 0.86, which was better than a single antibody and combined multiple antibody detection.

CONCLUSION

In-depth analysis of autoantibodies and reliable early diagnosis based on the neural network could guide specialized physicians to develop different treatment plans to prevent deterioration and enable early treatment with antirheumatic drugs for remission. Key Points • There are differences in the seropositive rate of autoimmune diseases. • This is the first study to use a cost-sensitive neural network model to diagnose RA disease in patients. • The diagnosis effect of the cost-sensitive neural network model is better than a single antibody and combined multiple antibody detection.

Monarticular rheumatoid arthritis of the elbow

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by symmetric inflammatory polyarthritis. However, RA limited to a single joint is extremely rare. Here, we report a middle-aged woman who presented with insidious right elbow arthritis. She had no other peripheral joint pain, tenderness or swelling. She had high-positive anti-cyclic citrullinated peptide antibodies. An MRI of the right elbow showed capsular distension, joint effusion and bone marrow oedema. Synovial biopsy revealed hyperplasia with lymphoplasmacytic infiltrate consistent with RA. Therapy with methotrexate 7.5 mg orally weekly was effective to control her inflammatory arthritis. This case highlights the relevance of synovial tissue analysis for patients presenting with chronic inflammatory monarthritis when the cause is not clinically evident, and the importance of considering RA even in the absence of polyarticular involvement. Delayed diagnosis and treatment of inflammatory monarthritis can lead to joint destruction and disability.

Impact of autoimmune serology test results on RA classification and diagnosis

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease and also the most severe arthritic disorder. The measurement of rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) in serum supports the diagnosis of RA, which gained increasing significance over the last 65 years. However, a high variability between RF and ACPA methods has been described, impacting the diagnostic performance of the current ACR/EULAR RA classification criteria.

The great number of commercially available assays, often lacking traceability to an international standard, is a major factor attributing to this in-between assay variability. The adoption of an international standard for ACPA, as is since long available for rheumatoid factor, is therefore highly desirable.

Further harmonization in clinical interpretation of RF/ACPA assays could be obtained by harmonization of the cut-offs, for both the low and high antibody levels, based on predefined specificity in disease controls. Reporting test result specific likelihood ratios (LR) adds value in the interpretation of autoantibody tests. However, a good understanding of the control population used to define antibody test result interval-associated LRs is crucial in defining the diagnostic performance characteristics of antibody serology.

Finally, specificity in RA classification can be improved by refining serological weight scoring taking into account the nature of the antibody, the antibody level and double RF + ACPA positivity.

Comparison of different assays for the detection of anticyclic citrullinated peptide antibodies in patients with rheumatoid arthritis

OBJECTIVE

To evaluate a novel fully automated immunoturbidimetric assay developed by Qiangsheng Biotechnology Company for the detection of anticyclic citrullinated peptide antibodies (anti-CCP) in serum of patients with rheumatoid arthritis (RA) and compare it to the conventional EUROIMMUN- anti-CCP ELISA. Two other commonly used automated assays, the Elecsys anti-CCP assay, an ECLIA that is run on the Modular Analystics E170 (Cobas Diagnostics, Germany), and an anti-CCP CLIA developed by YHLO that is run on the iFlash 3000 Chemiluminescence Immunoassay Analyzer, were included as reference standards.

METHODS

A total of 264 serum samples were collected from patients attending the First People's Hospital of Wenling affiliated to Wenzhou Medical University between July 2020 and November 2020. These included 131 serum samples collected from patients with RA, 70 serum samples collected from patients with other autoimmune diseases, and 63 serum samples collected from healthy controls at a physical examination. The clinical performance and sensitivity and specificity of the four anti-CCP assays for the diagnosis of RA were compared using receiver operating characteristic (ROC) curve analysis.

RESULTS

The Kappa statistic indicated almost perfect agreement between the EUROIMMUN-anti-CCP ELISA and the Elecsys anti-CCP ECLIA (Cobas) (0.863), the EUROIMMUN-anti-CCP ELISA and the anti-CCP CLIA (YHLO) (0.862), and the Elecsys anti-CCP ECLIA (Cobas) and the anti-CCP CLIA (YHLO) (0.816). On ROC curve analysis, AUC values were 0.955 for the EUROIMMUN-anti-CCP ELISA, 0.948 for the anti-CCP CLIA (YHLO), 0.947 for the Elecsys anti-CCP ECLIA (Cobas) and 0.903 for Qiangsheng, indicating all the assays had a good diagnostic performance for RA.

CONCLUSION

The anti-CCP assays provided similar diagnostic information. The novel fully automated immunoturbidimetric assay for anti-CCP developed by Qiangsheng Biotechnology Company may be especially useful for large scale clinical screening in RA as it has a shorter testing time than the commercially available alternatives.

Extra-articular involvement of rheumatoid arthritis in three seropositive patients in the absence of initial joint involvement

Introduction

Extra‐articular involvement (EAI) in rheumatoid arthritis (RA) is rare, severe and usually presents after years of joint involvement. Onset of RA as lung involvement has been published. We describe a series of three patients with strongly positive anti‐citrullinated peptide antibodies (ACPA) and rheumatoid factor (RF) positive in the absence of joint symptoms, but with significant EAI.

Methods

This is a descriptive case series of three patients evaluated in an academic medical center rheumatology clinic.

Results

A 50‐year‐old female presented with severe recurrent scleritis in the background of strongly positive ACPA, but no joint involvement. Her ocular disease responded well to rituximab. Four years later, she developed peripheral inflammatory arthritis consistent with RA. A 74‐year‐old male presented after developing recurrent steroid‐dependent serositis (pleuro‐pericarditis) and interstitial lung disease (ILD). Serology was notable for strongly positive ACPA, but no joint involvement. Serositis responded well to adalimumab. Two years after initial symptoms, he developed peripheral joint involvement after holding adalimumab. A 56‐year‐old female presented with an isolated, biopsy‐proven subcutaneous rheumatoid nodule. Subsequently, she developed pancytopenia and fatigue. She tested strongly positive for ACPA and RF. Bone marrow biopsy was negative for malignancy and she had no evidence of infection. She responded to steroids and hydroxychloroquine and had not developed joint involvement after 2 years of follow‐up.

Conclusion

EAI as an onset of RA is a complex and not easily recognized entity if typical joints involvement is not yet present. Early diagnosis may help guide specific therapy and prevent sequelae and co‐morbidities.

Chronobiology and Chronotherapy in Inflammatory Joint Diseases

Circadian rhythm perturbations can impact the evolution of different conditions, including autoimmune diseases. This narrative review summarizes the current understanding of circadian biology in inflammatory joint diseases and discusses the potential application of chronotherapy. Proinflammatory cytokines are key players in the development and progression of rheumatoid arthritis (RA), regulating cell survival/apoptosis, differentiation, and proliferation. The production and secretion of inflammatory cytokines show a dependence on the human day–night cycle, resulting in changing cytokine plasma levels over 24 h. Moreover, beyond the circadian rhythm of cytokine secretion, disturbances in timekeeping mechanisms have been proposed in RA. Taking into consideration chronotherapy concepts, modified-release (MR) prednisone tablets have been introduced to counteract the negative effects of night-time peaks of proinflammatory cytokines. Low-dose MR prednisone seems to be able to improve the course of RA, reduce morning stiffness and morning serum levels of IL-6, and induce significant clinical benefits. Additionally, methotrexate (MTX) chronotherapy has been reported to be associated with a significant improvement in RA activity score. Similar effects have been described for polymyalgia rheumatica and gout, although the available literature is still limited. Growing knowledge of chronobiology applied to inflammatory joint diseases could stimulate the development of new drug strategies to treat patients in accordance with biological rhythms and minimize side effects.

Identification of a Novel Serological Marker in Seronegative Rheumatoid Arthritis Using the Peptide Library Approach

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation mainly affecting the joints leading to cartilage and bone destruction. The definition of seropositive or seronegative RA is based on the presence or absence of rheumatoid factor (RF) and anti-citrullinated peptide antibodies (ACPAs). Other autoantibodies have been identified in the last decade such as antibodies directed against carbamylated antigens, peptidyl-arginine deiminase type 4 and v-Raf murine sarcoma viral oncogene homologue B. In order to identify relevant autoantigens, we screened a random peptide library (RPL) with pooled IgGs obtained from 50 patients with seronegative RA. Patients’ sera were then used in an ELISA test to identify the most frequently recognized peptide among those obtained by screening the RPL. Sera from age- and sex-matched healthy subjects were used as controls. We identified a specific peptide (RA-peptide) recognized by RA patients’ sera, but not by healthy subjects or by patients with other immune-mediated diseases. The majority of sera from seronegative and seropositive RA patients (73.8% and 63.6% respectively) contained IgG antibodies directed against the RA-peptide. Interestingly, this peptide shares homology with some self-antigens, such as Protein-tyrosine kinase 2 beta, B cell scaffold protein, Liprin-alfa1 and Cytotoxic T lymphocyte protein 4. Affinity purified anti-RA-peptide antibodies were able to cross react with these autoantigens. In conclusion, we identified a peptide that is recognized by seropositive and, most importantly, by seronegative RA patients’ sera, but not by healthy subjects, conferring to this epitope a high degree of specificity. This peptide shares also homology with other autoantigens which can be recognized by autoantibodies present in seronegative RA sera. These newly identified autoantibodies, although present also in a percentage of seropositive RA patients, may be considered as novel serum biomarkers for seronegative RA, which lacks the presence of RF and/or ACPAs.

B Cells in Rheumatoid Arthritis：Pathogenic Mechanisms and Treatment Prospects

Rheumatoid arthritis (RA) is a common, chronic, systemic autoimmune disease, and its clinical features are the proliferation of joint synovial tissue, the formation of pannus and the destruction of cartilage. The global incidence of RA is about 1%, and it is more common in women. The basic feature of RA is the body’s immune system disorders, in which autoreactive CD4⁺T cells, pathogenic B cells, M1 macrophages, inflammatory cytokines, chemokines and autoantibodies abnormally increase in the body of RA patients B cell depletion therapy has well proved the important role of B cells in the pathogenesis of RA, and the treatment of RA with B cells as a target has also been paid more and more attention. Although the inflammatory indicators in RA patients receiving B-cell depletion therapy have been significantly improved, the risk of infection and cancer has also increased, which suggests that we need to deplete pathogenic B cells instead of all B cells. However, at present we cannot distinguish between pathogenic B cells and protective B cells in RA patients. In this review, we explore fresh perspectives upon the roles of B cells in the occurrence, development and treatment of RA.

A fructosylated peptide derived from a collagen II T cell epitope for long-term treatment of arthritis (FIA-CIA) in mice

Rheumatoid arthritis (RA) is a systemic inflammatory autoimmune disease which affects primarily the joints. Peptides of several proteins have shown an effect in some experimental animal models of RA. We investigated arthritis development in male DBA/1 mice which were injected with bovine collagen II (bCII) and human fibrinogen (hFib) on days 0 and 21, leading to stable and reproducible disease induction in 100% of immunized mice (FIA-CIA). In a second study, two bCII-derived peptides were given three times in the course of 6 weeks after FIA-CIA induction to test for impact on arthritis. Mice were scored weekly for arthritis and anti-citrullinated peptide antibodies (ACPAs) were determined in the sera taken on days 0, 14, 35, 56 and 84. Histology of the hind paws was performed at the end of the experiment. Intravenous administration of peptide 90578, a novel fructosylated peptide derived from the immunodominant T cell epitope of bCII, at a dosage of 1 mg/kg resulted in significant beneficial effects on clinical outcome parameters and on the arthritis histology scores which was sustained over 12 weeks. Survival tended to be improved in peptide 90578-treated mice. Intravenous administration of pure soluble peptide 90578 without adjuvants is a promising approach to treat RA, with treatment starting at a time when ACPAs are already present. The results complement existing data on peptide "vaccination" of healthy animals, or on treatment using recombinant peptide expressing virus or complex biological compounds.

Validity and reliability of "Shriners Hospital for Children Upper Extremity Evaluation" in children with rheumatic diseases

INTRODUCTION/OBJECTIVES

The aim of this study was to investigate the validity and reliability of "Shriners Hospital for Children Upper Extremity Evaluation (SHUEE)" for children with rheumatic diseases.

METHODS

The study was carried out after obtaining the necessary permissions and retrospectively registered. The psychometric properties evaluated were reliability and concurrent validity. Reliability was determined by intra- and inter-observer agreement. Concurrent validity was performed using the Jebsen Taylor Hand Function Test (JTHFT), Abilhand-Rheumatoid Arthritis (Abilhand-RA), and Children Health Assessment Questionnaire (CHAQ). The validity and reliability of the evaluation were determined after the retest 1 week later.

RESULTS

Twenty children with rheumatic diseases were participated in to study. Intraclass coefficients ranged from 0.82 to 0.97 and the intraobserver reliability for SHUEE total and subscales were considered "excellent." Interobserver reliability was considered "excellent" for the SHUUE total score, spontaneous functional analysis and dynamic positional analysis, and "moderate" for grasp-release. A moderate negative correlation was determined between Spontaneous Functional Analysis and JTHFT (r =  - 0.63; p = 0.003).

CONCLUSION

SHUEE is a valid and reliable evaluation for children with rheumatic diseases. ClinicalTrials.org NCT04685434/21.12.2020 Key Points • SHUEE tends to be appropriate and acceptable to children with rheumatic diseases. • SHUEE can be used safely in the pediatric rheumatology group and it is beneficial in the clinical decision-making process. • SHUEE is a pioneering performance test that evaluates the quality of movement in pediatric rheumatology on a joint basis.

Genetic and expression deregulation of immunoregulatory genes in rheumatoid arthritis

Rheumatoid arthritis (RA) is one of the most common autoimmune diseases globally, and is an important public health concern, associating with early death and systemic complications. Although key development in RA treatment has already been made still RA affected individuals face comorbidity and disability. Therefore, there is a need to discover new risk factors in helping early diagnosis and treatment of RA. The present study is designed to assess the variations of Vitamin D receptor (VDR) and interleukin -6 (IL-6) in RA patients. Polymorphisms of said genes were calculated in 300 RA patients and 300 controls, using Tetra-ARMS polymerase chain reaction. Secondly, expression levels of selected genes were checked using the quantitative PCR (qPCR) and obtained results were evaluated using a different statistical test. Logistic regression analysis showed that frequency of mutant allele of VDR gene polymorphisms (rs11168268, OR = 4.84; 95% CI = 2.94-7.97; p = 0.0001; rs2248098, OR = 1.65; 95% CI = 1.07-2.54; p = 0.02) and IL-6 gene polymorphisms (rs184229712, OR = 2.47; 95% CI = 1.56-3.92, p = 0.0001; rs36215814, OR = 2.14; 95% CI = 1.30-3.53; p = 0.002) was observed significantly higher in RA patients vs controls. Expression analysis showed the significant upregulation of IL-6 (p < 0.0001) and downregulation of VDR gene (p < 0.0001) in RA cases vs controls. ROC curve analysis showed that downregulation of IL-6 (AUC = 0.86, p < 0.001) and upregulation of VDR (AUC = 0.77, p < 0.001) was act as the good diagnostic marker for detection/diagnosis of arthritis. In conclusions, data from the present study showed the significant involvement of VDR and IL-6 gene variations in RA pathogenesis.

Clinical, radiologic and serologic profile of patients with interstitial pneumonia with autoimmune features: a cross-sectional study

The current study aimed to characterize patients from a rheumatology referral center in north India, who satisfied the definition of interstitial pneumonia with autoimmune features (IPAF) as given by the American Thoracic Society and European Respiratory Society (ATS/ERS) consensus committee in 2015. Thirty-five adult patients aged 18 years and above, fulfilling the 2015 ATS/ERS criteria for IPAF were included in the study. The clinical and immunological profile, and radiologic findings on high-resolution computerized tomography thorax were noted. Antinuclear antibody (ANA) by indirect immunofluorescence at 1:320 titer and myositis-specific antibody (MSA) assays were performed. Non-parametric tests were used to compare variables between groups. The study cohort included predominantly female patients with a mean age of 50.6 ± 13 years and mean duration of disease of 38.8 ± 28.4 months. Majority of patients (49%) fulfilled the morphologic and serologic domains as per the IPAF consensus criteria and 31% patients had features in all three domains. Non-specific interstitial pneumonia was the most common pattern observed in 77% patients. Raynaud’s phenomenon and inflammatory arthritis were the predominant autoimmune features. Pulmonary arterial hypertension was documented in 60% of patients on echocardiography. Positive ANA at 1:320 dilution was present in all 26 patients tested, whereas extractable nuclear antigen and MSA assays detected autoantibodies in 49% and 51% of patients respectively. IPAF predominantly affected females in the age group of 50 years and above, with varied autoimmune manifestations and autoantibody profile.

Bone Erosions Detected by Ultrasound Are Prognostic for Clinical Arthritis Development in Patients With ACPA and Musculoskeletal Pain

Anti-citrullinated protein antibodies (ACPA) often precede onset of rheumatoid arthritis (RA) by years, and there is an urgent clinical need for predictors of arthritis development among such at-risk patients. This study assesses the prognostic value of ultrasound for arthritis development among ACPA-positive patients with musculoskeletal pain. We prospectively followed 82 ACPA-positive patients without clinical signs of arthritis at baseline. Ultrasound at baseline assessed synovial hypertrophy, inflammatory activity by power Doppler, and erosions in small joints of hands and feet. We applied Cox regression analyses to examine associations with clinical arthritis development during follow-up (median, 69 months; range, 24–90 months). We also compared the ultrasound findings among the patients to a control group of 100 blood donors without musculoskeletal pain. Clinical arthritis developed in 39/82 patients (48%) after a median of 6 months (range, 1–71 months). One or more ultrasound erosions occurred in 13/82 patients (16%), with none in control subjects (p < 0.001). Clinical arthritis development was more common among patients with baseline ultrasound erosions than those without (77 vs. 42%, p = 0.032), and remained significant in a multivariable Cox regression analysis that included previously described prognostic factors (HR 3.9, 95% CI 1.6–9.4, p = 0.003). Ultrasound-detected tenosynovitis was more frequent among the patients and associated with clinical arthritis development in a univariable analysis (HR 2.5, 95% CI 1.1–5.7, p = 0.031), but did not remain statistically significant in multivariable analysis. Thus, bone erosions detected by ultrasound are independent predictors of clinical arthritis development in an ACPA-positive at-risk population.

Trial Registration: Regional Ethics Committee in Linköping, Sweden, Dnr M220-09. Registered 16 December 2009, https://etikprovningsmyndigheten.se/.

ACPA Status Correlates with Differential Immune Profile in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a progressive erosive autoimmune disease that affects 1% of the world population. Anti-citrullinated protein autoantibodies (ACPA) are routinely used for the diagnosis of RA, however 20–30% of patients are ACPA negative. ACPA status is a delineator of RA disease endotypes with similar clinical manifestation but potentially different pathophysiology. Profiling of key peripheral blood and synovial tissue immune populations including B cells, T follicular helper (Tfh) cells and CD4 T cell proinflammatory cytokine responses could elucidate the underlying immunological mechanisms involved and inform a treat to target approach for both ACPA-positive and ACPA-negative RA. Detailed high dimensionality flow cytometric analysis with supervised and unsupervised algorithm analysis revealed unique RA patient peripheral blood B cell and Tfh cell profiles. Synovial tissue single cell analysis of B cell subpopulation distribution was similar between ACPA− and ACPA+ RA patients, highlighting a key role for specific B cell subsets in both disease endotypes. Interestingly, synovial tissue single cell analysis of CD4 T cell proinflammatory cytokine production was markedly different between ACPA− and APCA+ RA patients. RNAseq analysis of RA patient synovial tissue highlighted disease endotype specific gene signatures. ACPA status associates with unique immune profile signatures that reinforce the need for a treat to target approach for both endotypes of RA.

Improved classification of rheumatoid arthritis with a score including anti-acetylated ornithine antibodies

The presence of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (anti-CCP) autoantibodies contributes to the current rheumatoid arthritis (RA) classification criteria. These criteria involve stratification on antibody levels, which limits reproducibility, and underperform in the RA patients without RF and anti-CCP. Here, we have explored if two anti-acetylated peptide antibodies (AAPA), anti-acetylated lysine (AcLys) and anti-acetylated ornithine (AcOrn), could improve the performance of the current criteria. The analysis was done in 1062 prospectively-followed early arthritis (EA) patients. The anti-AcOrn were more informative than the anti-AcLys, the conventional RA antibodies and the anti-carbamylated protein antibodies. The anti-AcOrn produced a classification that did not require antibody levels and showed improved specificity (77.6% vs. 72.6%, p = 0.003) and accuracy (79.0% vs. 75.8%, p = 0.002) over the current criteria. These improvements were obtained with a scoring system that values concordance between anti-AcOrn, RF and anti-CCP. No significant gain was obtained in sensitivity (80.2% vs. 78.8%, p = 0.25) or in improving the classification of the RA patients lacking RF and anti-CCP, although the anti-AcOrn ranked first among the analysed new antibodies. Therefore, the anti-AcOrn antibodies could contribute to the improvement of RA classification criteria by exploiting antibody concordance.

Long-term follow-up of patients with anti-cyclic citrullinated peptide antibody-positive connective tissue disease: a retrospective observational study including information on the HLA-DRB1 allele and citrullination dependency

BACKGROUND

The anti-cyclic citrullinated peptide (CCP) antibody is a diagnostic biomarker of rheumatoid arthritis (RA). However, some non-RA connective tissue disease (CTD) patients also test positive for the anti-CCP antibody and, thus, may ultimately develop RA. We retrospectively investigated whether anti-CCP-positive non-RA CTD patients developed RA and attempted to identify factors that may differentiate RA-overlapping CTD from pure CTD.

METHODS

In total, 842 CTD patients with a primary diagnosis that was not RA were selected from our CTD database as of December 2012. Anti-CCP antibody titers were obtained from a retrospective chart review or measured using stored sera. RA was diagnosed according to the 1987 revised American College of Rheumatology classification criteria. Thirty-three anti-CCP-positive non-RA CTD patients were retrospectively followed up for the development of RA. Bone erosions on the hands and feet were assessed by X-ray. Citrullination dependency was evaluated by an in-house ELISA, the HLA-DRB1 allele was typed, and the results obtained were then compared between RA-overlapping and non-RA anti-CCP-positive CTD patients.

RESULTS

Two out of 33 anti-CCP-positive CTD patients (6.1%) developed RA during a mean follow-up period of 8.9 years. X-rays were examined in 27 out of the 33 patients, and only one (3.7%) showed bone erosions. The frequency of the HLA-DRB1 shared epitope (SE) and anti-CCP antibody titers were both significantly higher in anti-CCP-positive RA-overlapping CTD patients than in anti-CCP-positive non-RA CTD patients, while no significant differences were observed in citrullination dependency.

CONCLUSIONS

Anti-CCP-positive non-RA CTD patients rarely developed RA. HLA-DRB1 SE and anti-CCP antibody titers may facilitate the differentiation of RA-overlapping CTD from anti-CCP-positive non-RA CTD.

Comparison of the analytical and clinical performances of four anti-cyclic citrullinated peptide antibody assays for diagnosing rheumatoid arthritis

INTRODUCTION/OBJECTIVES

Anti-cyclic citrullinated peptide antibody (anti-CCP) is one of the most important serologic markers for diagnosing rheumatoid arthritis (RA). This study aimed to compare the analytical and clinical performances of the second- and third-generation anti-CCP assays.

METHODS

Four automated anti-CCP assays were evaluated: Chorus anti-CCP (Diesse Diagnostica), Elecsys anti-CCP (Roche Diagnostics), Atellica® IM anti-CCP IgG (Siemens Healthineers), and Quanta Flash® CCP3 (Inova Diagnostics Inc.). Analytical performance included the precision, linearity, correlation, and concordance rate. For evaluating the clinical performance, 240 patient samples (120 positive and 120 negative samples, determined by the Chorus anti-CCP assay) were used, including those with a diagnosis of RA (n = 132) and non-RA (n = 108). Using receiver operating characteristic (ROC) curve analysis, the sensitivity and specificity were evaluated.

RESULTS

All four assays that were evaluated showed good precision and linearity, and their correlation and concordance rates were in acceptable ranges. The area under the curve (AUC) values ranged from 0.888 to 0.914, showing a good diagnostic performance. The sensitivity and specificity of all assays were similar (88.0-97.2%).

CONCLUSIONS

All four anti-CCP assays showed good analytical and diagnostic performances for diagnosing RA. After adjusting the cutoff values, these assays are expected to show enhanced sensitivity and specificity. Key Points • Previous studies have described the diagnostic performance of a few immunologic markers in RA diagnosis, but nothing has been proven to be sufficiently good in clinical practice. • All four automated anti-CCP assays showed good analytical and diagnostic performances for diagnosing RA in clinical practice. • After adjusting the cutoff values, these assays are expected to show enhanced sensitivity and specificity. • The present study provides reassuring evidence that any of the studied commercially available anti-CCP tests for detecting rheumatoid arthritis provide similar diagnostic information to institutions that adopt these specific testing systems.

Diagnostic accuracy of 14-3-3 η protein in rheumatoid arthritis: A meta-analysis

AIM

To evaluate the overall diagnostic performance of 14-3-3 η protein in patients with rheumatoid arthritis (RA).

METHODS

PubMed, EMBASE, and Web of Science were searched to acquire eligible studies. Articles published in English before 20 February 2020 were included. Quality Assessment of Diagnostic Accuracy Studies 2 was used to evaluate the risk of bias and application concern of the included articles. Pooled analysis of diagnostic indicators of 14-3-3 η protein for RA was conducted by using a random effects model. Subgroup analysis was used to explore the sources of heterogeneity. Deeks' funnel plot asymmetry test was used to evaluate for the presence of publication bias.

RESULTS

A total of 13 studies (1554 positive and 1934 negative participants) were included. The pooled sensitivity and specificity were 0.73 (95% CI 0.71-0.75) and 0.88 (95% CI 0.87-0.90), respectively. The pooled positive/negative likelihood were 5.98 (95% CI 4.39-8.14) and 0.28 (95% CI 0.21-0.37), respectively. In addition, the pooled diagnostic odds ratio was 23.48 (95% CI 13.76-40.08) and the area under curve was 0.9245. The results of subgroup analysis indicated that ethnicity and control group might be the source of heterogeneity. The results of sensitivity analysis were stable. No significant publication bias was found.

CONCLUSIONS

The current evidence indicated that 14-3-3 η protein has moderate accuracy for the diagnosis of RA.

Association of Musculoskeletal and Radiological Features with Clinical and Serological Findings in Systemic Sclerosis: A Single-Centre Registry Study

AIM

Systemic sclerosis (SSc) is a chronic connective tissue disease with the clinical hallmark of skin thickening and tethering. Correlation of musculoskeletal features with other parameters should be considered in SSc patients.

METHODS

We reviewed the records of all patients who had more than one visit and standard anteroposterior radiography of hand. We used univariate analysis, and factors with p<0.05 were included in logistic regression to find out dependent factors.

RESULTS

Overall, 180 SSc patients were enrolled in our study, 161 (89.4%) of whom were women. Median age (IQR) was 47.0 years (16), and 52% had diffuse subtype of the disease. In multivariate analysis, tendon friction rubs (TFRs) was associated with the presence of calcinosis, muscle tenderness, and flexion contracture (FC) on physical examination (p<0.05). Arthritis showed no differences in the two subtypes of the disease (p=0.98), and in multivariate analysis, there were no correlations between radiographic arthritis and serological and clinical features. The radiographic results indicated that disease duration correlated with joint erosion, acro-osteolysis, resorption of distal ulna, calcinosis and radiologic FC (p< 0.05). Acro-osteolysis was more frequent in the dcSSc subtype, TFRs, and anti-TOPO I antibody. Radiologic FC showed association with skin score, calcinosis and haematocrit <30% (p<0.05). Joint flexion on radiography was associated with disease duration, modified Rodnan skin score, calcinosis, and low haematocrit (P<0.01).

CONCLUSION

Disease duration was a main dependent factor for developing joint erosion, acro-osteolysis, bone resorption, calcinosis, and flexion contracture on hand radiography. Acro-osteolysis presented in the severe form of the disease. Acro-osteolysis was the only dependent variable associated with bone demineralization.

T follicular helper cell subsets: a potential key player in autoimmunity

Follicular helper T (Tfh) cells are one of CD4+ helper T subsets which promote B cell maturation, activation and antigen-specific antibody production. Autoantibodies are hallmarks of autoimmune diseases, and crucial contributions of Tfh cells in development of these diseases are now evident. Deregulation of Tfh activities can contribute to a pathogenic autoantibody production and can play an important role in the promotion of autoimmune diseases. These days multiple researchers reported three subpopulations which has distinct effector functions in Tfh cells: Tfh1, Tfh2 and Tfh17 cells. In this review, we summarize the observed alterations in whole Tfh cells and subset distribution during autoimmune diseases.

Developmental stages of tertiary lymphoid tissue reflect local injury and inflammation in mouse and human kidneys

Tertiary lymphoid tissues (TLTs) are inducible ectopic lymphoid tissues in chronic inflammatory states and function as sites of priming local immune responses. We previously demonstrated that aged but not young mice exhibited multiple TLTs after acute kidney injury and that TLTs were also detected in human aged and diseased kidneys. However, the forms of progression and the implication for kidney injury remain unclear. To clarify this we analyzed surgically resected kidneys from aged patients with or without chronic kidney disease as well as kidneys resected for pyelonephritis, and classified TLTs into three distinct developmental stages based on the presence of follicular dendritic cells and germinal centers. In injury-induced murine TLT models, the stages advanced with the extent of kidney injury, and decreased with dexamethasone accompanied with improvement of renal function, fibrosis and inflammation. Kidneys from aged patients with chronic kidney disease consistently exhibited more frequent and advanced stages of TLTs than those without chronic kidney disease. Kidneys of patients with pyelonephritis exhibited more frequent TLTs with more advanced stages than aged kidneys. Additionally, TLTs in both cohorts shared similar locations and components, suggesting that TLT formation may not be a disease-specific phenomenon but rather a common pathological process. Thus, our findings provide the insights into biological features of TLT in the kidney and implicate TLT stage as a potential marker reflecting local injury and inflammation.

Impact of Cyclic Citrullinated Peptide Antibody Level on Progression to Rheumatoid Arthritis in Clinically Tested Cyclic Citrullinated Peptide Antibody-Positive Patients Without Rheumatoid Arthritis

OBJECTIVE

To investigate the risk of progression to rheumatoid arthritis (RA) in patients who were cyclic citrullinated peptide (CCP) antibody positive without RA at initial presentation.

METHODS

We performed a retrospective cohort study of CCP+ individuals seen at a US tertiary care system between 2009 and 2018 who were without RA or other systemic rheumatic disease by medical record review at the time of CCP antibody positivity. Progression to classifiable RA was determined through medical record review. We investigated the risk of progression to RA overall and stratified by CCP antibody level (low: >1 to 2× the upper limit of normal [ULN]; medium: >2 to 3× ULN; high: >3× ULN). Multivariable Cox regression estimated the hazard ratio (HR) and 95% confidence interval (95% CI) for RA by CCP antibody level.

RESULTS

We identified 340 CCP+ patients who were without RA or other rheumatic disease at baseline. During 1,047 person-years of follow-up, 73 patients (21.5%) developed RA. The risk of progression to RA increased with CCP antibody level, with 46.0% (95% CI 34.7-55.3) of patients with high-level CCP antibodies progressing to RA by 5 years. Compared to low CCP antibody level, medium (HR 3.00 [95% CI 1.32-6.81]) and high (HR 4.83 [95% CI 2.51-9.31]) CCP antibody levels were strongly associated with progression to RA, adjusting for age, sex, body mass index, smoking, family history of RA, and rheumatoid factor level.

CONCLUSION

Among CCP+ patients without RA, the risk for progression to RA increased substantially with increasing CCP antibody level. This study provides further support for close monitoring for development of RA among CCP+ patients and identifying strategies to mitigate this risk.

Gingimaps: Protein Localization in the Oral Pathogen Porphyromonas gingivalis

Porphyromonas gingivalis is an oral pathogen involved in the widespread disease periodontitis. In recent years, however, this bacterium has been implicated in the etiology of another common disorder, the autoimmune disease rheumatoid arthritis. Periodontitis and rheumatoid arthritis were known to correlate for decades, but only recently a possible molecular connection underlying this association has been unveiled. P. gingivalis possesses an enzyme that citrullinates certain host proteins and, potentially, elicits autoimmune antibodies against such citrullinated proteins. These autoantibodies are highly specific for rheumatoid arthritis and have been purported both as a symptom and a potential cause of the disease. The citrullinating enzyme and other major virulence factors of P. gingivalis, including some that were implicated in the etiology of rheumatoid arthritis, are targeted to the host tissue as secreted or outer-membrane-bound proteins. These targeting events play pivotal roles in the interactions between the pathogen and its human host. Accordingly, the overall protein sorting and secretion events in P. gingivalis are of prime relevance for understanding its full disease-causing potential and for developing preventive and therapeutic approaches. The aim of this review is therefore to offer a comprehensive overview of the subcellular and extracellular localization of all proteins in three reference strains and four clinical isolates of P. gingivalis, as well as the mechanisms employed to reach these destinations.

Relation Between Anti-CCP Antibodies and Sharp Score in Rheumatoid Arthritis

Introduction

Rheumatoid arthritis (RA) is a chronic, inflammatory, systemic rheumatic disease, very complex, with many different forms, progressive course, with pronounced changes in the joints, still unknown etiology and poorly understood pathology. Assessing of structural change can be done with proposed scores which observe changes on wrist and wrist joints, as a Sharp score.

Aim

To examine the correlation between Anti-Citrullinated Protein Antibodies (Anti-CCP) values and Sharp score, and to determine the importance of Sharp score in the progression of RA.

Methods

The study had prospective character and followed patients in the period from January 1, 2017 to December 31, 2017. The study included 40 patients with RA. At the beginning of the follow-up of patients, X-ray of hands and feet were performed.

Results

Out of total of 40 patients, 34 or 85% had a follow-up examination after one year. Of these, 14 patients (41.2%) were reported to have complications. The subjects were divided into two groups according to Anti-CCP values. First group included patients with Anti-CCP values <4 and second those who had Anti-CCP> 4. Statistical analysis of the number of patients with complications at first and repeated examination indicated that there were no significant differences and that the sample was consistent between the first and repeated results (p> 0.05). Patients with higher Anti-CCP values also had a higher Sharp score with statistically significant differences during repeated examination (p <0.05). Correlation analysis shows that there was statistically significant (p <0.05) positive correlation with Anti-CCP values, and that an increase in values leads to an increase in the Sharp score (first measurement rho = 0.193, p> 0.05; repeated measurement rho = 0.645, p <0.0001). No statistically significant differences in Sharp score values at the first examination were compared with the repeated examination, but there was a statistically significant difference after one year in patients with complications (X2 = 13,388; p = 0.001), indicating that the Sharp score reflects disease progression.

Conclusion

Anti-CCP values are also directly correlated with the Sharp score, which should be routine in both initial and repeated examination of a patient with RA. Sharp's score represents a marker of progression as well as of therapeutic modality of RA.

Rheumatoid Arthritis: Seropositivity versus Seronegativity; A Comparative Cross-sectional Study Arising from Moroccan Context

INTRODUCTION

Rheumatoid arthritis (RA) is biologically marked by a positive serum rate of rheumatoid factor (RA) and/or anti-citrullinated protein antibodies (ACPA). Nevertheless, 20% of RA cases remain seronegative.

OBJECTIVE

The main purpose of this study, is to bring out the clinical, biological, imaging, therapeutic, and evolutionary distinctions between seropositive RA and seronegative one.

METHODS

This is an observational cross-sectional study that involves patients with RA admitted in the rheumatology department, from the period between January 2012 and January 2018. RA seronegativity is described as the absence of both RF and ACPA, while seropositivity is recognized by the presence of at least one of the two antibodies.

RESULTS

294 patients were included, of which 90% were seropositive and 10% seronegative. Therefore, RA in this study is seropositive most often. The bivariate analysis underscored plenty of differences, statistically notable, according to the RA immune status. In fact, patients with seropositive RA had more synovitis (p=0.049), more deformities (p=0.01), and more bone destruction on radiographs (p=0.04). Furthermore, RA in this Moroccan study was quite severe (p=0.006) and got more complicated by systemic manifestations (p=0.02). Whereas, no distinction was brought up between the two groups, concerning the use of biotherapy. As for the multivariate study, seropositive RA in these patients, had greater severity (p=0.009, OR=4.53) and was more deforming (p=0.03 OR=2.45).

CONCLUSION

RA in our Moroccan context is dominated by the seropositive form. This seropositivity is often coupled with clinical severity and joint destruction, resulting in more deformities.

Importance of 14-3-3eta, anti-CarP, and anti-Sa in the diagnosis of seronegative rheumatoid arthritis

Background/aim

Rheumatoid arthritis (RA) is an autoimmune disease characterized by synovial inflammation. The study aimed to assess serum 14-3-3eta, anti-CarP, and anti-Sa in seronegative RA (SNRA) patients who were treatment-naïve as well as in healthy subjects. This is the first study in the literature to examine these autoantibodies together in SNRA patients.

Materials and methods

Forty-five treatment-naïve SNRA patients and 45 healthy subjects were recruited. Drugs change the levels of autoantibodies; therefore, patients who took any medication had been excluded from our study. Anti-carbamylated protein, anti-Sa, and 14-3-3eta were measured by using three different ELISA kits.

Results

Median serum concentration of healthy controls in 14-3-3eta was 0.02 (0.02–0.27) ng/mL. Median serum concentration of SNRA patients in 14-3-3eta was 1.00 (0.48–1.28) ng/mL. Data were analyzed with Mann–Whitney U tests; the P-value was <0.001 in 14-3-3eta. Receiver operating characteristic (ROC) curve analysis showed that 14-3-3eta in SNR compared to healthy controls had a significant (P < 0.001) area under the curve (AUC) of 0.90 (95% confidence interval, 0.83–0.96). At a cutoff of ≥0.33 ng/mL, the ROC curve yielded a sensitivity of 88.9%, a specificity of 82.2%, a positive predictive value of 83.3%, and a negative predictive value of 88.1%.

Conclusion

We found that 14-3-3eta can be used as a diagnostic marker in SNRA.

Linkage of Periodontitis and Rheumatoid Arthritis: Current Evidence and Potential Biological Interactions

The association between rheumatoid arthritis (RA) and periodontal disease (PD) has been the focus of numerous investigations driven by their common pathological features. RA is an autoimmune disease characterized by chronic inflammation, the production of anti-citrullinated proteins antibodies (ACPA) leading to synovial joint inflammation and destruction. PD is a chronic inflammatory condition associated with a dysbiotic microbial biofilm affecting the supporting tissues around the teeth leading to the destruction of mineralized and non-mineralized connective tissues. Chronic inflammation associated with both RA and PD is similar in the predominant adaptive immune phenotype, in the imbalance between pro- and anti-inflammatory cytokines and in the role of smoking and genetic background as risk factors. Structural damage that occurs in consequence of chronic inflammation is the ultimate cause of loss of function and disability observed with the progression of RA and PD. Interestingly, the periodontal pathogen Porphyromonas gingivalis has been implicated in the generation of ACPA in RA patients, suggesting a direct biological intersection between PD and RA. However, more studies are warranted to confirm this link, elucidate potential mechanisms involved, and ascertain temporal associations between RA and PD. This review is mainly focused on recent clinical and translational research intends to discuss and provide an overview of the relationship between RA and PD, exploring the similarities in the immune-pathological aspects and the possible mechanisms linking the development and progression of both diseases. In addition, the current available treatments targeting both RA and PD were revised.

Immunogenicity of a rheumatoid arthritis protective sequence when acquired through microchimerism

HLA class II genes provide the strongest genetic contribution to rheumatoid arthritis (RA). HLA-DRB1 alleles encoding the sequence DERAA are RA-protective. Paradoxically, RA risk is increased in women with DERAA⁺ children born prior to onset. We developed a sensitive qPCR assay specific for DERAA, and found 53% of DERAA^-/- women with RA had microchimerism (Mc; pregnancy-derived allogeneic cells) carrying DERAA (DERAA-Mc) vs. 6% of healthy women. DERAA-Mc quantities correlated with an RA-risk genetic background including DERAA-binding HLA-DQ alleles, early RA onset, and aspects of RA severity. CD4⁺ T cells showed stronger response against DERAA⁺ vs. DERAA^- allogeneic cell lines in vitro, in line with an immunogenic role of allogeneic DERAA. Results indicate a model where DERAA-Mc activates DERAA-directed T cells that are naturally present in DERAA^-/- individuals and can have cross-reactivity against joint antigens. Moreover, we provide an explanation for the enigmatic observation that the same HLA sequence differentially affects RA risk through Mendelian inheritance vs. microchimeric cell acquisition.

Potential involvement of OX40 in the regulation of autoantibody sialylation in arthritis

OBJECTIVE

An increased proportion of circulating follicular helper T (Tfh) cells was reported in rheumatoid arthritis (RA), but it remains uncertain how Tfh cells affect antibody hyposialylation. We investigated the regulation of autoantibody hyposialylation by Tfh cells in RA using murine model.

METHODS

Behaviours of Tfh cells and their function on B cell promotion were analysed. Change of arthritogenicity and sialylation of autoantibodies during the course of arthritis was examined by mass spectrometry. Tfh-mediated regulation of hyposialylation was investigated, and the responsible cell surface molecule was specified both in vitro and in vivo. The relation between circulating Tfh cells and hyposialylation was analysed in patients with RA.

RESULTS

An increase in Tfh, particularly interleukin-17 producing Tfh (Tfh17) cells, at the onset of arthritis and their enhancement of autoantibody production were found. Autoantibodies at the onset phase demonstrated stronger inflammatory properties than those at the resolution phase, and mass spectrometric analysis revealed their difference in sialylation. In vitro coculture showed enhanced hyposialylation by the Tfh cells via OX40, which was highly expressed in the Tfh and Tfh17 cells. Blockade of OX40 prevented the development of arthritis with reduction in Tfh17 cells and recovery of autoantibody sialylation. Analysis of patients with RA showed abundance of OX40-overexpressing Tfh17 cells, and their proportion correlated negatively with the expression of α2,6-sialyltransferase 1, an enzyme responsible for sialylation.

CONCLUSIONS

OX40 expressed on Tfh cells can regulate autoantibody sialylation and play a crucial role in the development of autoimmune arthritis.

Lifetime Pesticide Use and Antinuclear Antibodies in Male Farmers From the Agricultural Health Study

Farming and pesticide use have been associated with systemic autoimmune diseases, and while certain organochlorine insecticides and other pesticides are suspected to influence risk, the role of specific pesticides in the development of systemic autoimmunity is not known. We measured serum antinuclear autoantibodies (ANA) by immunofluorescence on Hep-2 cells in 668 male farmers in the study of Biomarkers of Exposure and Effect in Agriculture (BEEA; 2010-2013), an Agricultural Health Study (AHS) subcohort. We examined ANA in relation to lifetime use of 46 pesticides first reported at AHS enrollment (1993-1997) and updated at intervals through BEEA enrollment. Odds ratios (OR) and 95% confidence intervals (CI) were estimated after adjusting for age, state, education, season of blood draw, current pesticide use, and correlated pesticides. Having ANA antibodies (3 or 4+ intensity at a 1:80 dilution, 21% of study participants) was associated with a reported history of seeking medical care due to exposure to pesticides (OR 2.15; 95%CI 1.17, 3.95), use of the fumigant methyl bromide (OR 3.16; 95%CI 1.05, 9.5), and use of petroleum oil/distillates (OR 1.50; 95%CI 1.00, 2.25). Using a higher threshold (3 or 4+ at a 1:160 dilution, 9%) ANA positivity was associated with the carbamate insecticide aldicarb (OR 4.82; 95%CI 1.33, 17.5) and greater combined use of four cyclodiene organochlorine insecticides (top tertile of intensity-weighted lifetime days vs. no use; OR T3 3.20; 95%CI 1.10, 9.27). By contrast, greater use of non-cyclodiene organochlorine insecticides was inversely associated with ANA (1:80 dilution 3 or 4+, OR T3 0.24; 95%CI 0.08, 0.72). Specific autoantibodies (to extractable nuclear antigens and anti-dsDNA), measured on those with ANA detected at the 1:80 dilution 3 or 4+, were seen in 15 individuals (2%), and were associated with use of two or more cyclodiene organochlorine insecticides and several other pesticides (e.g., carbofuran, ethylene dibromide). These findings suggest that specific pesticide exposures may have long-term effects on ANA prevalence and support the hypothesis that certain organochlorine insecticides may increase the risk of developing systemic autoimmunity.