Significance of antibodies to cardiolipin in unselected patients with systemic lupus erythematosus: clinical and laboratory associations. The SLE Study Group

Anticardiolipin Antibody Plays a More Important Role Than Anti-β2-Glycoprotein I Antibody in Activating Complement in Patients with Lupus Nephritis

Objective

This research aimed to explore the correlation between antiphospholipid antibodies (aPLs) and complement activation in lupus nephritis (LN) patients.

Methods

A retrospective analysis was carried out on patients diagnosed with LN based on renal biopsy from June 2019 to June 2022. The study assessed levels of IgM, IgA, and IgG subtypes of anticardiolipin antibodies (aCLs) and anti-β2-glycoprotein I (anti-β2-GPI) antibodies. Pathological and clinical data were collected concurrently with the renal biopsy.

Results

The analysis included 76 LN patients, with 44.7% testing positive for aPLs. LN patients with positive aPLs exhibited increased hematuria, higher SLEDAI scores, reduced serum C3 and C4 levels, and more C1q deposits in the glomerulus compared to those with negative aPLs (P<0.05). Correlation analysis demonstrated the inverse relationships between IgG-aCL levels and serum C3 and C4 levels (r=-0.29, P=0.005; r=-0.24, P=0.016, respectively), as well as a positive correlation with C4 deposits in the glomerulus (r=0.20, P=0.041).

Conclusion

This investigation suggests that aPLs, particularly IgG-aCLs, may be associated with the severity of LN and could contribute to the activation of classical complement pathways.

Risk of livedo with antiphospholipid antibodies in patients with systemic lupus erythematosus: A systematic review and meta-analysis

Background

Livedo is a well-known skin condition in patients with systemic lupus erythematosus (SLE) which correspond to small vessels involvement. The influence of antiphospholipid antibodies (aPL) on the occurrence of livedo is controversial. The aim of our study was to estimate the risk of livedo associated with aPL in patients with SLE.

Methods

We conducted a systematic review and meta-analysis of the literature from 1977 to 2021 to estimate the risk of livedo in SLE patients according to different aPL profiles. Data sources were PubMed, Embase, Cochrane Library, hand search, and reference lists of studies. Studies were selected if they included SLE patients with descriptions of the exposure to aPL and the outcome ( livedo). Two independent investigators assessed study eligibility, quality, and extracted patient characteristics from each study as well as exposure (aPL) and outcome ( livedo). Risk estimates were pooled using random effects models and sensitivity analyses. For all stages of the meta-analysis, we followed the PRISMA guidelines. PROSPERO registration number: CRD42015027377.

Results

Of the 2,355 articles identified, 27 were included with a total of 4,810 SLE patients. The frequency of livedo was 25.5% in aPL-positive patients and 13.3% in aPL-negative patients. The overall Odds Ratio (OR) for livedo in aPL-positive patients compared to aPL-negative patients was 2.91 (95% CI; 2.17–3.90). The risk of livedo was significantly increased for most of aPL subtypes, including lupus anticoagulant (LA) (OR = 4.45 [95% CI; 2.21–8.94]), IgG anticardiolipin (OR = 3.95 [95% CI; 2.34–6.65]), and IgG anti-β2-glycoprotein 1 (OR = 3.49 [95% CI; 1.68–7.27]).

Conclusions

We demonstrated in this meta-analysis an excess risk of livedo in aPL-positive SLE patients compared to aPL-negative patients. For daily practice, in patients with SLE, livedo associated with aPL could correspond to a peculiar group of patients with small vessel disease. Livedo could be a good candidate for inclusion in future classification criteria for antiphospholipid syndrome.

Antiphospholipid antibodies and the risk of autoimmune hemolytic anemia in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

According to criteria for the classification of Systemic Lupus Erythematosus (SLE), autoimmune hemolytic anemia is one of the disease-defining hematologic disorders together with thrombocytopenia. Since the recognition of Antiphospholipid Syndrome (APS), hemolytic anemia was frequently reported but several studies yielded contradictory results on the association between antiphospholipid antibodies (aPL) and hemolytic anemia. Therefore, we evaluated the association of aPL and autoimmune hemolytic anemia in SLE patients by conducting a systematic review and meta-analysis of available literature.

METHODS

MEDLINE, EMBASE, Cochrane Library, congress abstracts, and reference lists of eligible studies were searched from 1987 to 2020. Studies were selected if they included SLE patients with descriptions of exposure to aPL and occurrence of hemolytic anemia. Three reviewers extracted study characteristics and association data from published reports. Risk estimates were pooled using random effects models and sensitivity analyses. We followed the PRISMA guidelines for all stages of the meta-analysis (Supplemental Table). PROSPERO registration number: CRD42015027376.

RESULTS

From 3555 articles identified, 38 studies met inclusion criteria and included 8286 SLE patients. 20.5% of aPL-positive SLE patients had hemolytic anemia compared to 8.7% in aPL-negative SLE patients. The overall pooled Odds Ratio (OR) for hemolytic anemia in aPL positive patients was 2.83 (95% CI; 2.12-3.79). Among aPL subtypes, the risk of hemolytic anemia was highest for lupus anticoagulant (OR = 3.37 [95% CI; 2.26-5.04]) and, antiβ₂Glycoprotein I antibodies (OR = 3.21 [95% CI; 1.54-6.72]), especially IgM antiβ₂Glycoprotein I (OR = 3.01 [95% CI; 1.26, 7.24]).

CONCLUSIONS

The occurrence of hemolytic anemia was strongly associated with presence of aPL in SLE patients. Interestingly, IgM isotypes indicate an increased risk of hemolytic anemia in SLE.

Association of antiphospholipid antibodies with clinical activity and renal pathological activity in patients with lupus nephritis

OBJECTIVES

This study aimed to investigate the association of antiphospholipid antibodies (aPL) with clinical activity and renal pathological activity in patients with lupus nephritis (LN).

METHODS

Levels of anticardiolipin () antibodies, anti-β2-glycoprotein I (anti-β2-GPI) antibodies and lupus anticoagulant (LAC) were measured, and other clinical and pathological data were also obtained during the same period before renal biopsy.

RESULTS

A total of 83 patients with LN were included in this study, 40 patients (48.2%) in the s positive group and 43 patients in the aPL negative group. LN patients with positive aPL had significantly higher SLEDAI (p = 0.012), more hematuria (p = 0.043), lower serum C3 (p = 0.003) and C4 (p = 0.014), and a higher pathological activity index (p = 0.012), more micro-thrombosis (p = 0.046) and more C3 deposits (p = 0.038) in the glomerulus than patients with negative aPL The level of IgG- was significantly correlated with SLEDAI and serum level of C3 (r = 0.44, p < 0.001; r = -0.39, p = 0.003, respectively). The level of IgM- was significantly correlated with SLEDAI, and serum levels of C3 and C4 (r = 0.27, p = 0.014; r = -0.22, p = 0.041; r = -0.23, p = 0.035, respectively).

CONCLUSIONS

Our work suggests that aPL, especially, are correlated with both clinical activity and renal pathological activity in patients with LN.

Antiphospholipid Antibodies and Autoimmune Haemolytic Anaemia: A Systematic Review and Meta-Analysis

The relationship between antiphospholipid antibodies (aPL) and autoimmune haemolytic anaemia (AIHA) has never been systematically addressed. The aim of this study is to assess the link between aPL and AIHA in adult systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS). This study performed an EMBASE/PubMed search from inception to June 2019 and meta-analysis using Peto’s odds ratios. The pooled prevalence (PP) of IgG/IgM anticardiolipin (aCL) and lupus anticoagulant (LA) was greater in AIHA +ve than AIHA −ve patients (34.7% vs. 27.6%, p = 0.03; 33.3% vs. 21.8%, p < 0.0001; 20.9% vs. 8.3%, p = 0.01). The PP of AIHA was greater in: (1) IgG and IgM aCL +ve than −ve patients (21.8% vs. 11.1%, p = 0.001 and 18.7% vs. 6.3%, p < 0.0001), (2) in SLE related APS than in primary APS patients (22.8% vs. 3.9% p < 0.0001), (3) in APS +ve than APS −ve SLE patients (23.2% vs. 8.4%, p = 0.01), and (4) in thrombotic APS than non-thrombotic APS/SLE patients (26.8% vs. 10%, p = 0.03). The PP of IgG/IgM aCL and LA was greater in DAT +ve than DAT −ve patients (42.4% vs. 12.8%, p < 0.0001; 26.2% vs. 12.8%, p = 0.03 and 29.2% vs. 15.7%, p = 0.004 respectively). It was found that AIHA prevalence is maximal in SLE with aPL/APS, low-moderate in SLE without aPL and minimal in PAPS. Moreover, AIHA is rightly included among the classification criteria for SLE but not for APS/aPL. The significance of an isolated DAT positivity remains unclear in this setting

CNS dysfunction in the antiphospholipid syndrome

Though many neurological deficits have been described in the antiphospholipid syndrome (APS), only stroke is well establishedand accepted as a diagnosticcriterion in this disease. We review clinical data obtainedfrom a large series of cases regardingstroke, dementia, epilepsy, chorea, migraine, white matter disease and behavioralchangesin APS or linked to laboratory criteria such as antiphospholipid antibodies (aPL). The contribution of animal models to our understanding of these manifestations of APS is stressed, especially regarding the cognitive and behavioral aspects for which we have established model systems in the mouse. These models utilize immunization of mice with b2-glycoprotein I, a central autoantigen in APS, which induces persistent high levels of aPL. These mice develop hyperactive behavior after a period of four to five months as well as deficits in learning and memory and are potentiallyvaluableas a system in which to study the pathogenesisand treatment of cognitive and behavioral aspects of APS. Another model we have developed, in which IgG from APS patients induce depolarization of brain synaptoneurosomes, may serve as a model for the pathogenesis of epilepsy in APS.

Pattern of MRI brain in neuro-psychiatric SLE. Effect of anti-phospholipid antibodies: A study at a tertiary care teaching hospital

OBJECTIVE

To compare the neuro-radiologic findings in Systemic lupus erythematosus (SLE) patients with and without antiphospholipid antibodies (aPL) in different neuro-psychiatric manifestations.

METHODS

This cross-sectional comparative study was carried out at King Khalid University Hospital, a tertiary care teaching hospital, Riyadh, Saudi Arabia from June 2012 to January 2015. Ninety seven SLE patients with neuro-psychiatric manifestations were included in the study and divided into two groups. Group I (50 patients) SLE with aPL and group II (47 patients) SLE without aPL. We compared Demographic features, clinical manifestations and magnetic resonance imaging (MRI) brain findings.

RESULTS

Demographic and clinical characteristics of two groups were similar. In Group-I, anticardiolipin antibodies (aCL) were most common (86%). In patients with headache, most of the patients in Group-I had white matter hyperintensities (WMHIs) (50% vs 27%) while most of the patients in Group-II had normal MRI brain (38% vs 73%). Similarly WMHIs were found more in Group-I patients with seizures (60% vs 21%), while ischemia/infarction, atrophy and normal MRI were found in Group-II. MRI brain in patients with neurological deficit and psychiatric disorder were not much different in both the groups.

CONCLUSION

We found no statistically significant differences in frequencies of MRI brain abnormalities in SLE patients with and without aPL antibodies. Each of the three aPL may have a variable effect on the brain.

The relevance of "non-criteria" clinical manifestations of antiphospholipid syndrome: 14th International Congress on Antiphospholipid Antibodies Technical Task Force Report on Antiphospholipid Syndrome Clinical Features

The purpose of this task force was to critically analyze nine non-criteria manifestations of APS to support their inclusion as APS classification criteria. The Task Force Members selected the non-criteria clinical manifestations according to their clinical relevance, that is, the patient-important outcome from clinician perspective. They included superficial vein thrombosis, thrombocytopenia, renal microangiopathy, heart valve disease, livedo reticularis, migraine, chorea, seizures and myelitis, which were reviewed by this International Task Force collaboration, in addition to the seronegative APS (SN-APS). GRADE system was used to evaluate the quality of evidence of medical literature of each selected item. This critical appraisal exercise aimed to support the debate regarding the clinical picture of APS. We found that the overall GRADE analysis was very low for migraine and seizures, low for superficial venous thrombosis, thrombocytopenia, chorea, longitudinal myelitis and the so-called seronegative APS and moderate for APS nephropathy, heart valve lesions and livedo reticularis. The next step can be a critical redefinition of an APS gold standard, for instance derived from the APS ACTION registry that will include not only current APS patients but also those with antiphospholipid antibodies not meeting current classification criteria.

Chinese SLE treatment and research group registry: III. association of autoantibodies with clinical manifestations in Chinese patients with systemic lupus erythematosus

We investigated the characteristics of Chinese SLE patients by analyzing the association between specific autoantibodies and clinical manifestations of 2104 SLE patients from registry data of CSTAR cohort. Significant (P < 0.05) associations were found between anti-Sm antibody, anti-rRNP antibody, and malar rash; between anti-RNP antibody, anti-SSA antibody, and pulmonary arterial hypertension (PAH); between anti-SSB antibody and hematologic involvement; and between anti-dsDNA antibody and nephropathy. APL antibody was associated with hematologic involvement, interstitial lung disease, and a lower prevalence of oral ulcerations (P < 0.05). Associations were also found between anti-dsDNA antibody and a lower prevalence of photosensitivity, and between anti-SSA antibody and a lower prevalence of nephropathy (P < 0.05). Most of these findings were consistent with other studies in the literature but this study is the first report on the association between anti-SSA and a lower prevalence of nephropathy. The correlations of specific autoantibodies and clinical manifestations could provide clues for physicians to predict organ damages in SLE patients. We suggest that a thorough screening of autoantibodies should be carried out when the diagnosis of SLE is established, and repeated echocardiography annually in SLE patients with anti-RNP or anti-SSA antibody should be performed.

Antiphospholipid antibodies and the brain: a consensus report

This report discusses the difference between antiphospholipid antibodies (aPL) as a predictor for first and recurrent ischemic stroke, whether or not concomitant systemic lupus erythematosus (SLE) increases aPL-associated risk, and the association of aPL with other neurological manifestations. The neurological manifestations covered in this report were selected because they are among the most common, including cognitive dysfunction, headache, multiple sclerosis and seizures/epilepsy. Recommendations are made regarding further research that is needed to clarify remaining uncertainties.

International consensus statement on an update of the classification criteria for definite antiphospholipid syndrome (APS)

New clinical, laboratory and experimental insights, since the 1999 publication of the Sapporo preliminary classification criteria for antiphospholipid syndrome (APS), had been addressed at a workshop in Sydney, Australia, before the Eleventh International Congress on antiphospholipid antibodies. In this document, we appraise the existing evidence on clinical and laboratory features of APS addressed during the forum. Based on this, we propose amendments to the Sapporo criteria. We also provide definitions on features of APS that were not included in the updated criteria.

Diseases of white matter and schizophrenia-like psychosis

OBJECTIVE

To analyse the available data regarding the presentation of psychosis in diseases of central nervous system (CNS) white matter.

METHOD

The available neurological and psychiatric literature on developmental, neoplastic, infective, immunological and other white matter diseases was reviewed.

RESULTS

A number of diseases of the white matter can present as schizophrenia-like psychoses, including leukodystrophies, neoplasms, velocardiofacial syndrome, callosal anomalies and inflammatory diseases.

CONCLUSIONS

Production of psychotic symptoms may result from functional asynchrony of interdependent regions, due to alterations in critical circuits as a result of pathology. The nature, location and timing of white matter pathology seem to be the key factors in the development of psychosis, especially during the critical adolescent period of association area myelination. Diseases that disrupt the normal formation of myelin appear to cause psychosis at higher rates than those that disrupt mature myelinated structures. Diffuse rather than discrete lesions, in particular those affecting frontotemporal zones, are also more strongly associated with schizophrenia-like psychosis. These illnesses point to the central role that white matter plays in maintaining CNS connectivity and to how pathology of the white matter may contribute to the neurobiology of psychosis.

Anticardiolipin and antinuclear antibodies in epilepsy—a population-based cross-sectional study

Increased prevalence of autoantibodies has been suggested in patients with epilepsy. This study determined the presence of autoantibodies in a representative cohort of 960 patients with epilepsy. The frequency of antinuclear antibodies (ANA), immunoglobulin G class anticardiolipin antibodies (aCL) and anti-B2-glycoprotein I antibodies were studied in 960 consenting adult patients with epilepsy and in 580 population-based reference subjects identified from the Finnish Population Registry. Overall the frequencies of the autoantibodies studied did not differ between patients with epilepsy and reference subjects. aCL were present in 4.5% of the patients and in 5.0% of the reference subjects and 17% of both the patients and the reference subjects had antinuclear antibodies. However, patients with partial epilepsy for > or =30 years were three times more likely to have aCL than patients with partial epilepsy for <10 years. Patients with partial epilepsy and > or=1 seizure per month were 2.2 times more likely to have aCL than patients with partial epilepsy with <1 seizure per month. Moreover, ANA tended to be more frequent among patients with > or =1 seizure per month. No association was found between the major antiepileptic drugs and autoantibodies. Overall the frequencies of the autoantobodies studied were similar in the large epilepsy cohort and in matched reference subjects from the general population. However, a long duration of epilepsy and poor seizure control were associated with an increased presence of aCL in patients with partial epilepsy.

The prevalence, onset, and clinical significance of antiphospholipid antibodies prior to diagnosis of systemic lupus erythematosus

OBJECTIVE

To determine whether antiphospholipid antibodies (aPL) occur before the diagnosis of systemic lupus erythematosus (SLE) and before initial clotting events, and whether their presence early in the disease course influences clinical outcome.

METHODS

Serum samples obtained from 130 lupus patients before and after SLE diagnosis were screened for IgG and IgM aPL using an anticardiolipin (aCL) enzyme-linked immunosorbent assay. Medical records of all patients were carefully reviewed for data on the time of onset of SLE features meeting clinical criteria and on disease manifestations.

RESULTS

Twenty-four patients (18.5%) were positive for IgG and/or IgM aCL prior to SLE diagnosis. Anticardiolipin antibodies appeared from 7.6 years prior to SLE diagnosis to within the same month as SLE diagnosis, with a mean onset occurring 3.0 years before SLE diagnosis. Additionally, aCL presence early in the disease process seemed to predict a more severe clinical outcome; these patients eventually met an average of 6.1 of the 11 classification criteria for SLE, compared with 4.9 criteria for other patients (P < 0.001). The early aCL-positive population also had more frequent renal disease, central nervous system disease, thrombocytopenia, and clotting events. In this population, aCL preceded initial thrombotic events by a mean of 3.1 years.

CONCLUSION

Anticardiolipin antibodies in SLE patients tend to precede initial clotting events by several years. Furthermore, the presence of early, prediagnosis aPL seems to herald a more varied, severe clinical course with earlier onset in patients with SLE.

Neurological and neuroendocrine-cytokine inter-relationship in the antiphospholipid syndrome

Although many neurological deficits have been described in the antiphospholipid syndrome (APS), only stroke is well established and accepted as a diagnostic criterion in the disease. We presently review clinical data obtained from large series of cases regarding stroke, dementia, epilepsy, chorea, migraine, white-matter disease, and behavioral changes in APS, or linked-to-laboratory criteria such as antiphospholipid antibodies (aPL). The contribution of animal models to our understanding of these manifestations of APS is stressed, especially regarding the cognitive and behavioral aspects for which we have established model systems in the mouse. These models utilize immunization of mice with beta(2)-glycoprotein1, a central autoantigen in APS, which induces persistent high levels of aPLs. These mice develop hyperactive behavior after a period of four months, as well as deficits in learning and memory, and are potentially valuable as a system in which to study the pathogenesis and treatment of cognitive and behavioral aspects of APS. We have developed another model, in which IgGs from APS patients induce depolarization of brain synaptoneurosomes, and which may serve as a model for the pathogenesis of epilepsy in APS. Hormonal changes are another potential CNS manifestation of APS and this may be potentially linked to the systemic and central effects of cytokines such as interleukin-3. Better understanding of the link between APS and neurological or neuroendocrine manifestations other than stroke will reveal whether they can be used as clinical criteria for the diagnosis of APS and, it is hoped, lead to better treatment.

Anti-C1q antibodies may help in diagnosing a renal flare in lupus nephritis

It is still uncertain which, if any, immunologic parameters may help diagnose a renal flare of lupus nephritis. Anti-C1q antibody (Ab) titers have been elevated in patients with lupus with renal involvement, but little information is available on whether the titers are different in quiescent and active phases of lupus nephritis. In this study, we compared anti-C1q Ab titers with other serological test results in 48 patients with biopsy-proven lupus nephritis to assess which parameter could offer the best reliability for differentiating between quiescent and active phases of lupus nephritis. Serum C3 and C4 levels, as well as anti-double-stranded DNA, antiendothelial cell, anti-C1q, and antiphospholipid Ab titers, were evaluated in patients with quiescent renal disease (38 samples) and those with clinical evidence of renal activity (23 samples). Only anti-C1q Ab titers correlated with active renal disease in both univariate (P < 0.0001) and multivariate analysis (P < 0.0001), with a sensitivity of 87% and a specificity of 92%. In six patients, immunologic parameters were measured serially. In all patients, the high anti-C1q Ab titers returned to normal values after treatment-induced remission. The other serological parameters did not show a significant association with renal disease activity. In patients with biopsy-proven lupus nephritis, anti-C1q Ab titers appear to be strongly related to renal disease activity. Their measurement may be useful for confirming the diagnosis of renal flares of lupus nephritis.

Elevated anticardiolipin antibodies in autoimmune haemolytic anaemia irrespective of underlying systemic lupus erythematosus

In patients with systemic lupus erythematosus (SLE) and concomitant Coombs positive autoimmune haemolytic anaemia (AIHA) anticardiolipin antibodies (aCL) are found more frequently and at higher titres than in SLE patients without AIHA. In order to assess if aCL elevation is primarily associated with the underlying SLE, or with AIHA itself, we examined AIHA patients with and without underlying SLE for the presence of aCL. aCL (IgG and IgM) were determined by ELISA in 74 SLE patients without AIHA, 22 SLE patients with AIHA, 50 patients with idiopathic AIHA (warm-reactive autoantibodies), 52 patients with idiopathic AIHA (cold-reactive autoantibodies) and 50 healthy controls. The mean IgG and IgM aCL titres in SLE patients without AIHA (IgG 37.0 U/ml, IgM 8.9 U/ml) were significantly elevated compared with the values in healthy controls (IgG 9.1 U/ml, IgM 3.2 U/ml; P < 0.005). The mean aCL levels in SLE patients with AIHA (IgG 53.2 U/ml, IgM 28.2 U/ml) were higher than in SLE patients without AIHA (P = 0.09 for IgG, P < 0.005 for IgM). Interestingly, the mean aCL levels of patients with idiopathic AIHA (warm-reactive autoantibody type: IgG 29.2 U/ml, IgM 19.3 U/ml; cold-reactive autoantibody type: IgG 27.4 U/ml, IgM 18.9 U/ml) were also significantly elevated compared with healthy controls P < 0.001). As aCL are elevated not only in SLE (with and without concomitant AIHA) but also in idiopathic AIHA it can be speculated that aCL are involved in the pathomechanism of autoantibody-induced erythrocyte destruction per se irrespective of an underlying SLE.

Elevated levels of anticardiolipin antibodies and epilepsy in lupus patients

To examine the association between anticardiolipin (aCL) antibodies and epilepsy, we investigated the serum titers of aCL antibodies in a total 252 systemic lupus erythematosus (SLE) patients recruited in a prospective study. Twenty-one cases with epilepsy which were not attributable to any causes other than SLE were identified after being followed-up for five years. The clinical manifestations were recorded and blood samples were tested for the presence of aCL antibodies (IgG, IgM and IgA isotypes). Among 21 patients with epilepsy, 12 (57.1%), 2 (9.5%) and 2 (9.5%), respectively, had elevated baseline serum levels of IgG, IgM and IgA aCL antibodies. There was a dose-response relationship between risk of seizure and the baseline serum level of aCL antibodies (P < 0.01). The odds ratio of developing seizure were 3.7 for those who had a high level of aCL antibodies compared with those without a detectable level of aCL antibodies as the referent. Our results indicate that epilepsy as a primary neuropsychiatric event among lupus patients is associated with a high titer of aCL antibodies.