The value of IgA antiphospholipid testing for diagnosis of antiphospholipid (Hughes) syndrome in systemic lupus erythematosus.
Bibliographic record
Abstract
OBJECTIVE: It is recognized that the presence of IgG and IgM anticardiolipin antibodies (aCL) and lupus anticoagulant (LAC) is associated with thrombosis in patients with antiphospholipid syndrome (APS). Some reports have shown that testing for IgA anticardiolipin and anti-beta2-glycoprotein antibodies (anti-beta2-GPI) provides extra diagnostic help in patients with APS, while other authors could not support this data. We designed this cross sectional study to determine the prevalence of IgA aCL, anti-beta2-GPI, and antiprothrombin antibodies and to study their clinical significance in a large cohort of patients with systemic lupus erythematosus (SLE). METHODS: This study comprised 134 SLE patients (126 women; median age 37.5 yrs, range 16-72). The median duration of the disease was 9 years, range 0.1-38. Of these, 55 (41%) had a history of thrombotic events: 22 (40%) presented an arterial event, 22 (40%) a venous event, and 11 (20%) both arterial and venous events. Of 49 women who had been pregnant, 18 (37%) gave a history of recurrent pregnancy loss. Thrombocytopenia was present in 14/127 patients (11%). Forty patients (30%) were diagnosed as APS secondary to SLE, 23 (17%) had IgG/M aCL and/or LAC without clinical features of APS, and 71 (53%) were SLE patients who were repeatedly negative for IgG/M aCL or LAC. IgG, IgM, IgA aCL and anti-beta2-GPI were detected by ELISA. Antibodies directed to prothrombin were detected by 2 ELISA using prothrombin coated on irradiated plates (aPT) and phosphatidylserine/prothrombin complex (aPS/PT) as antigen. RESULTS: IgA aCL were found in 18/134 (13%) patients. Of these, 3 (17%) had IgA aCL as well as IgG/M aCL, and 2 (11%) had IgG/M aCL and anti-beta2-GPI. Of the 18 patients positive for IgA aCL, 8 were also positive for LAC. Of these, one (5%) patient had IgA aCL as well as other isotype of aCL, and 7 (39%) patients had both aCL and anti-beta2-GPI. None of these patients had binding of IgA aPT or aPS/PT. Of the entire group of 18 patients, 5 (28%) had IgA aCL as the sole aPL. Four of 5 of these patients were diagnosed as SLE but had no antiphospholipid (aPL) related clinical manifestations. We found no association between the presence of IgA aCL and clinical manifestations of APS. IgA anti-beta2-GPI were found in 8/134 (6%) patients. Of these, one (12.5%) had IgA anti-beta2-GPI as well as IgG/M anti-beta2-GPI and aCL. Of the 8 patients positive for IgA anti-beta2-GPI, 6 (75%) were also positive for LAC. Of these, one (12.5%) patient presented with IgA anti-beta2-GPI along with other isotypes of aCL, and 4 (50%) patients with aCL and other isotype of anti-beta2-GPI. One patient (12.5%) had IgA anti-beta2-GPI along with LAC only, and one patient (12.5%) who was diagnosed as SLE had no aPL related clinical manifestation but had IgA anti-beta2-GPI as the sole aPL. CONCLUSION: IgA aCL and anti-beta2-GPI are found in SLE, usually along with IgG and/or IgM isotypes. Testing for IgA aCL and anti-beta2-GPI is not a helpful screening test and does not contribute to the recognition of APS in SLE. IgA aPT and aPS/PT are not present in patients with SLE, therefore there is no need to test for these antibodies.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.003 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".