Primary antiphospholipid syndrome evolving into systemic lupus erythematosus

"Non-criteria" antiphospholipid antibodies add value to antiphospholipid syndrome diagnoses in a large Chinese cohort

BACKGROUND

Despite expansion in the 2006 Sydney antiphospholipid syndrome (APS) classification criteria to include IgG/IgM anti-β2-glycoprotein (aβ2GPI) antibodies in addition to IgG/IgM anti-cardiolipin antibodies (aCL) and lupus anticoagulant (LAC), some individuals with clinical features of APS remain seronegative (seronegative APS or SNAPS) and are at risk of recurrent thrombosis and pregnancy morbidities. Our aim was to assess the value of "non-criteria" aPL antibodies to detect these SNAPS patients.

METHODS

One hundred ninety-two APS patients, 90 SNAPS patients, 193 autoimmune disease controls, and 120 healthy controls were evaluated. Ten antiphospholipid antibodies (aPLs) were tested using commercial kits, including 5 non-criteria aPLs: anti-phosphatidylserine/prothrombin antibodies (aPS/PT) IgG/IgM, aCL IgA, aβ2GPI IgA, and anti-β2GPI Domain 1 (aβ2GPI-D1) IgG.

RESULTS

Up to 60.9% of the SNAPS and 93.5% of APS patients were detected by at least one non-criteria aPL. aPS/PT IgG had the highest Youden index in classifying APS and SNAPS from controls. aPS/PT IgG and aβ2GPI Domain 1 IgG seem to be the most significant risk factors for thrombotic events and pregnancy morbidity, respectively. aPS/PT IgG/IgM and aβ2GPI-D1 IgG were detected in some SNAPS patients, while IgA isotypes of aCL/aβ2GPI tended to appear together with other biomarkers. The combined analysis showed enhanced diagnostic performance with the inclusion of non-criteria aPLs.

CONCLUSIONS

Recognition of SNAPS patients is critical for clinical management and prevention of potential thrombotic and obstetric adverse events. The non-criteria antiphospholipid antibodies help to identify a considerable portion (60.9%) of these patients who otherwise may remain untreated and at clinical risk.

Laboratory testing for the antiphospholipid syndrome: making sense of antiphospholipid antibody assays

The antiphospholipid syndrome (APS) is an autoimmune condition characterised by a wide range of clinical features (primarily thrombosis and/or obstetric related), associated with the presence of antiphospholipid antibodies (aPL) as detected by a diverse range of laboratory tests. APS remains a significant diagnostic challenge for clinicians across a wide range of specialities, largely due to issues related to laboratory testing as well as the expanding range of reported clinical manifestations of APS. The laboratory issues include limitations in detailed knowledge by both clinical and laboratory personnel regarding the 'complete' range of available aPL tests, as well as ongoing problems with assay reproducibility and standardisation. aPL are identified using diverse laboratory procedures based on one of two distinct test processes, namely solid phase and liquid phase assays. The former includes anticardiolipin antibodies (aCL) and anti-β(2)-glycoprotein I antibodies (aβ(2)GPI). The latter are centred on clot-based tests that are used to identify the so-called lupus anticoagulant (LA). This article will discuss: (i) issues related to laboratory testing for APS in terms of the currently available solid-phase and liquid-phase assays, and identifiable biases resulting from these tests usually being performed in different laboratories; (ii) current problems with calibration, standardisation and reproducibility of these assays; (iii) pre-analytical, analytical and post-analytical considerations and ongoing initiatives for improvement; (iv) issues related to potential combinations/panels of available aPL tests; and (v) the entities of seropositive APS, seronegative APS and non-APS aPL-positivity. In doing so, this review will hopefully help bridge the two disciplines of haematology and immunology ('representing' liquid-phase and solid-phase aPL testing, respectively), by improving the understanding of those working in each of these disciplines of the merits and limitations of the assays performed in the other discipline, and encouraging inter-discipline cooperation in the reporting of aPL test results.

The antiphospholipid syndrome: a large elephant with many parts or an elusive chameleon disguised by many colours?

The antiphospholipid syndrome (APS) is characterized by a range of clinical features (primarily thrombosis and/or obstetric-related), together with the presence of antiphospholipid antibody (aPL) as detected by a diverse range of laboratory tests. APS remains a significant diagnostic and management challenge for clinicians across a wide range of specialties, some 30 years after APS was first described as a discrete clinical entity. This is due to ongoing issues regarding nomenclature, the diagnosis of APS in individual patients, the expanding range of recognized clinical manifestations and of APS-related laboratory tests, and management issues in particular APS patient subgroups (including obstetric and catastrophic APS). In addition to the presence of appropriate clinical features, the diagnosis of APS fundamentally requires the finding of positive aPL test result(s), which is hampered by ongoing problems with assay reproducibility and standardization. This review focuses on ongoing dilemmas and issues related to clinical and laboratory aspects of APS including: (1) diagnostic challenges posed by the protean clinical manifestations of APS; (2) current nomenclature and recent proposals for revision of the 2006 international classification criteria; (3) an overview of some key issues related to aPL testing; (4) potential pitfalls of applying the APS classification criteria as diagnostic criteria; and (5) the controversial subgroups of seronegative APS and non-APS aPL positivity.

Antinucleosome antibodies in primary antiphospholipid syndrome: a hint at systemic autoimmunity?

BACKGROUND

Antinucleosome antibodies (anti-NCS) are reported to be highly sensitive and specific for systemic lupus erythematosus (SLE) and to correlate with disease activity. They may appear in early stages of the disease, in particular before anti-dsDNA antibodies, being a potential marker for identifying patients susceptible to SLE. Patients with primary antiphospholipid syndrome (PAPS) may develop full-blown SLE but there is no evidence for markers predictive for that.

AIM

To evaluate whether anti-NCS may be predictors for full-blown or lupus like disease (LL) in a cohort of PAPS patients.

METHODS

A multicentric cohort of 105 PAPS patients was tested for IgG/IgM anti-NCS by using a home made assay with H1-stripped chromatin as antigen.

RESULTS

Eighty-one out of 105 (77%) of the patients were positive for anti-NCS; medium-high titre results were present only in 49/105 (46%). Anti-NCS were more frequently detected in PAPS+LL, but no relationship with clinical/serological features was found, except for a weak correlation with anti-dsDNA antibodies. Two PAPS patients evolved into full-blown SLE during the follow-up and displayed high titre anti-NCS many years before.

CONCLUSIONS

Our findings suggest that anti-NCS might be added to the mosaic of autoimmune phenomena characterizing PAPS patients and in particular those with more chance to evolve to SLE.

Long-term follow-up in 128 patients with primary antiphospholipid syndrome: do they develop lupus?

We retrospectively studied a large cohort of patients with primary antiphospholipid syndrome (APS) from 4 different referral centers to analyze the clinical and serologic features and, specifically, to determine the number of patients going on to develop systemic lupus erythematosus (SLE) or other autoimmune disease after long-term follow-up. The study included 128 unselected patients with primary APS who fulfilled the Sapporo International Criteria from 4 different tertiary hospitals in the United Kingdom, Mexico, and Spain. The patients had attended the referral centers between January 1987 and July 2001. We reviewed clinical and serologic characteristics according to a pre-established protocol. We used univariate analysis with the chi-squared or Fisher exact test and logistic regression to analyze possible factors related to the coexistence of SLE and APS. Ninety-seven female and 31 male patients fulfilled the criteria, with a median age of 42 +/- 12 years (range, 16-79 yr), and with a mean follow-up of 9 +/- 3 years (range, 2-15 yr). The main manifestations included deep vein thrombosis in 62 patients (48%), arterial thrombosis in 63 (49%) patients, pregnancy loss in 177/320 (55%) cases, and pulmonary embolism in 37 (30%) patients. Other clinical manifestations were migraine in 51 (40%) patients, thrombocytopenia in 48 (38%), livedo reticularis in 47 (37%), and valvular disease in 27 (21%). Serologic findings were anticardiolipin antibodies (aCL) IgG positive in 110 (86%) patients, aCL IgM in 36 (39%), lupus anticoagulant in 71 (65%), antinuclear antibodies in 47 (37%), and positive Coombs test in 5 (4%) patients. During the follow-up and after a median disease duration of 8.2 years (range, 1-14 yr), 11 (8%) patients developed SLE, 6 (5%) developed lupus-like disease, and 1 (1%) developed myasthenia gravis. The remaining 110 patients (86%) continued to have primary APS. After the univariate analysis, a family history of lupus, the presence of Raynaud phenomenon, migraine, psychiatric features, multiple sclerosis-like features, hemolytic anemia, low C3 and C4, and Coombs positivity conferred a statistically significant risk for the subsequent development of SLE (p < 0.05). Only the presence of Coombs positivity had statistical significance (odds ratio, 66.4; 95% confidence interval, 1.6-2714; p = 0.027) after the logistic regression evaluation. The current study confirms that progression from primary APS to SLE or lupus-like disease is unusual, even after a long follow-up. Only 3 patients developed anti-dsDNA antibodies. The presence of a positive Coombs test might be a marker for the development of SLE in patients with primary APS.

Primary anti-phospholipid antibody syndrome (APS): current concepts

Primary anti-phospholipid syndrome (APS) is a thrombophilic state characterized by recurrent arterial and venous thrombosis, recurrent pregnancy loss, and the presence of circulating anti-phospholipid antibodies that may be responsible for thrombophilia and pregnancy morbidity. Ophthalmologic features are present in 15-88% of the patients with primary APS, thus ophthalmologists are one of the first physicians to whom the patient will present. An accurate diagnosis may save the patient from recurrent, potentially life-threatening thrombosis. In the U.S.A., an estimated 35,000 new cases of APS-related venous thrombosis occur each year in a population that is several decades younger than the patient population typically affected by thrombosis. Clinical features, such as chorea, transverse myelitis, cardiac valvular lesions, and accelerated atherosclerosis, are hypothesized to be due to a direct tissue-antibody interaction and cannot be explained purely by thrombosis. The use of recently proposed, well-defined diagnostic criteria, and better standardization of laboratory assays for the anti-phospholipid antibodies should help enable epidemiological surveys to establish the prevalence of these antibodies in patients with thrombosis and in the general population. Diagnosis of APS should be considered in all patients with recurrent systemic or ocular thrombosis in the absence of known risk factors. Several well-designed prospective studies show an increased risk of thrombosis in the presence of medium to high antibody level. With ocular involvement in as many as 88% of APS patients, an ophthalmic assessment should be an integral part of the clinical work-up of any patient with suspected or confirmed APS. The presence of isolated ocular thrombophilia with persistently elevated anti-phospholipid antibodies or lupus coagulant should confirm the diagnosis of APS. Management of these patients must be a multi-disciplinary effort with either a rheumatologist or a hematologist having the overall responsibility for coordinating treatment and monitoring the patient's immune status and anticoagulation. Treatment of isolated ocular thrombophilia in the presence of moderate to high titers of antiphospholipid antibodies should be on the same principles as patients with APS to prevent recurrent ocular or cerebral thrombosis.

Ovulation induction and early pregnancy loss in a woman susceptible to autoimmune diseases: a possible interrelationship

We report a 34-year-old woman with sequentially occurring autoimmune diseases that are possibly triggered by numerous ovulation inductions. At the ages of 26-32 years, she experienced 27 uncontrolled ovulation induction cycles using clomiphene citrate (CC) or CC plus human menopausal gonadotropin plus human chorionic gonadotropin. She became pregnant at the ages of 27, 30 and 31 with subsequent pregnancy loss in the 28th, 8th and 10th week of gestation, respectively. Insulin-dependent diabetes mellitus (IDDM) developed at the age of 28. During the second year of ovulation induction, at the age of 27, she developed arthralgia that worsened and became migratory from the age of 31. Thrombocytopenia appeared at the age of 33. The diagnosis of systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) was established at the age of 34. To the best of our knowledge, this is the first case of concurrent IDDM, SLE and APS in a patient associated with ovulation inductions. Excessive levels of estradiol achieved during the ovulation inductions could play a role in the expression of multiple autoimmune diseases in the susceptible woman.

Immunological abnormalities in primary APS evolving into SLE: 6 years follow-up in women with repeated pregnancy loss

We have performed a prospective study to determine the prevalence of immunological abnormalities and the evolution from primary antiphospholipid syndrome (APS) into systemic lupus erythematosus (SLE) in women who had had unexplained repeated pregnancy loss (PL) and APS. Of 105 women with abortions or fetal deaths, 33(31%) fulfilled criteria for APS. Among these patients with primary APS, 24% had antinuclear antibodies (ANA), 91% had elevated circulating immune complexes (CIC), 70% had low total haemolytic complement (CH100), 52% had low levels of complement 4 (C4) and 30% had low levels of complement 3 (C3), in a significantly higher prevalence than women whose pregnancies were successful (control group). Through out a 6 y follow-up, 3 (9%) of the patients with APS who had autoimmune related abnormalities when entered into the study developed features of lupus like disease (LLD) or fullblown SLE. Our findings suggest that women with unexplained repeated PL with APS who presented with positive ANA, high levels of CIC, low levels of CH100, C3 and C4, may define a subset of patients exhibiting immunological alterations similar to those of SLE. These parameters may help in the assessment of prognosis in APS patients with PL. Those patients should be carefully surveyed with regard to the development of connective tissue diseases.