Prevalence of antiphospholipid antibodies in Chilean patients with rheumatoid arthritis

IgA is the predominant isotype of anti-β2 glycoprotein I antibodies in rheumatoid arthritis

Background

The aim of this study was to determine the frequency of anti‐cardiolipin antibodies (aCL) and anti‐β2 glycoprotein I antibodies (aβ2GPI) among Tunisian patients with rheumatoid arthritis (RA).

Methods

Ninety RA patients with positive anti‐cyclic citrullinated antibodies (anti‐CCP) and 90 healthy blood donors (HBD) were studied. aCL and aβ2GPI of isotype IgG, IgA and IgM were detected by ELISA.

Result

The frequency of antiphopholipid antibodies (aPL) (aCL and/or aβ2GPI) was significantly higher in patients with RA than in HBD (35.5% vs 11.1%, P = .0001). The frequencies of aCL and aβ2GPI were significantly higher in patients than in healthy subjects (15.5% vs 5.5%, P = .04 and 32.2% vs 11.1%, P = .0005 respectively). aβ2GPI‐IgA were significantly more frequent in patients than in the control group (26.7% vs 7.8%, P = .0007). In patients, aβ2GPI‐IgA were significantly more frequent than aβ2GPI‐IgG (26.7% vs. 6.7%, P = .0003) and aβ2GPI‐IgM (26.7% vs 5.6%, P = .0001). In RA patients, the frequency of aβ2GPI was significantly higher than that of aCL (32.2% vs 15.5%, P = .008). aβ2GPI‐IgA was significantly more frequent than aCL‐IgA (26.7% vs 4.4%, P = .00005). The average titer of anti‐CCP in aPL positive patients was significantly higher than in aPL negative patients (170.6 ± 50 RU/mL vs 147.7 ± 51 RU/mL, P = .04). Significant correlation was found between aβ2GPI‐IgA and anti‐CCP (r = .235, P = .026).

Conclusions

aPL and particularly aβ2GPI‐IgA are frequent in RA and are correlated with anti‐CCP.

Pregnancy-Related Challenges in Systemic Autoimmune Diseases

The awareness of pregnancy-related physiologic changes and complications is critical for the appropriate assessment and management of pregnant patients with systemic autoimmune diseases. The overlapping features of physiologic and pathological changes, selected autoantibodies, and the use of potentially teratogenic medications can complicate their management during pregnancy. While pregnancy in lupus patients presents an additional risk to an already complex situation, in patients with no disease activity, the risk of a future pregnancy-related complication is relatively low. Anti-Ro and anti-La antibodies increase the risk of neonatal lupus erythematosus, eg, photosensitive rash and irreversible congenital heart block. Antiphospholipid antibodies increase the risk of pregnancy morbidity, eg, fetal loss and early preeclampsia. Pregnancy usually has a positive effect on rheumatoid arthritis; however, a disease flare is common during the postpartum period. Both the rheumatologist and the obstetrician should partner throughout the pregnancy to manage patients for successful outcomes.

Association between antiphospholipid antibodies and arterial thrombosis in patients with rheumatoid arthritis

OBJECTIVES

Antiphospholipid antibodies (aPL) are present in a proportion of patients with rheumatoid arthritis but their clinical significance remains unclear. We investigated the association between aPL and thrombotic events in rheumatoid arthritis patients.

METHODS

In this cross-sectional study, aPL profiles were evaluated in 376 rheumatoid arthritis patients in accordance with the standard guidelines. Clinical and radiographic data were retrospectively collected.

RESULTS

aPL were identified in 39 patients (10.4%). Lupus anticoagulant was the most common subtype (n = 25, 6.6%); anti-cardiolipin antibodies and anti-β₂ glycoprotein I antibodies were detected in six and 12 patients (1.6% and 3.2%), respectively. Compared to the aPL-negative group, aPL-positive patients included more male patients (41.0% vs. 15.4%, P < 0.001) and more smokers (41.0% vs. 16.0%, P = 0.001). There was no difference between the two groups in age, disease duration and body mass index, or the frequency of diabetes, hypertension or dyslipidaemia. Of note, arterial thromboses were more common in the aPL-positive than the aPL-negative group (12.8% vs. 2.1%, P = 0.004), whereas the frequency of venous thrombosis did not differ between the two groups (0.0% vs. 0.9%, P = 1.000). On multivariate regression analysis, aPL, age, hypertension, dyslipidaemia and baseline C-reactive protein level were independently associated with arterial thrombotic events (all P values < 0.05).

CONCLUSION

aPL was found in a subset of rheumatoid arthritis patients, who were more often smokers, and aPL was independently associated with development of arterial thrombosis. This result suggests that aPL may contribute to an increased risk of arterial thrombosis in rheumatoid arthritis patients.

The coexistence of antiphospholipid syndrome and systemic lupus erythematosus in Colombians

OBJECTIVES

To examine the prevalence and associated factors related to the coexistence of antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE) in a cohort of Colombian patients with SLE, and to discuss the coexistence of APS with other autoimmune diseases (ADs).

METHOD

A total of 376 patients with SLE were assessed for the presence of the following: 1) confirmed APS; 2) positivity for antiphospholipid (aPL) antibodies without a prior thromboembolic nor obstetric event; and 3) SLE patients without APS nor positivity for aPL antibodies. Comparisons between groups 1 and 3 were evaluated by bivariate and multivariate analysis.

RESULTS

Although the prevalence of aPL antibodies was 54%, APS was present in just 9.3% of SLE patients. In our series, besides cardiovascular disease (AOR 3.38, 95% CI 1.11-10.96, p = 0.035), pulmonary involvement (AOR 5.06, 95% CI 1.56-16.74, p = 0.007) and positivity for rheumatoid factor (AOR 4.68, 95%IC 1.63-14.98, p = 0.006) were factors significantly associated with APS-SLE. APS also may coexist with rheumatoid arthritis, Sjögren's syndrome, autoimmune thyroid diseases, systemic sclerosis, systemic vasculitis, dermatopolymyositis, primary biliary cirrhosis and autoimmune hepatitis.

CONCLUSIONS

APS is a systemic AD that may coexist with other ADs, the most common being SLE. Awareness of this polyautoimmunity should be addressed promptly to establish strategies for controlling modifiable risk factors in those patients.

Antiphospholipid antibodies in rheumatoid arthritis: identifying the dominoes

Antiphospholipid antibodies (aPL) occur in a variety of autoimmune, malignant, and infectious diseases, with or without the thrombotic or obstetric sequelae that characterize the antiphospholipid syndrome. Although many studies have focused on the clinical implications of aPL in systemic lupus erythematosus, few have specifically addressed the questions facing rheumatologists caring for rheumatoid arthritis patients who are concomitantly positive for aPL. Such a clinical scenario requires current knowledge of antiphospholipid syndrome diagnosis criteria, test reliability, conditions causing temporal positivity of aPL, and treatment risks and benefits. Recently researched factors possibly integral to rheumatoid arthritis's increased morbidity and mortality and related to aPL include oxidatively modified low-density lipoprotein antibodies, homocysteine, annexins, infectious agents, beta estradiol, and specific gene polymorphisms. This review presents current scientific research addressing the pathophysiologic mechanisms and clinical implications of aPL in rheumatoid arthritis.