Prevalence Of aPL Research Articles

Lupus anticoagulant: a marker for stroke and venous thrombosis in primary Sjögren’s syndrome

Antiphospholipid antibodies (aPL) and antiphospholipid syndrome (APS) have been described in primary Sjögren's syndrome (pSS) with controversial findings regarding aPL prevalence and their association with thrombotic events. We evaluated 100 consecutive pSS patients (American-European criteria) and 89 age-gender-ethnicity-matched healthy controls for IgG/IgM anticardiolipin (aCL), IgG/IgM anti-beta2-glycoprotein-I (aβ2GPI), and lupus anticoagulant (LA) (positivity according to APS Sydney's criteria). Clinical analysis followed standardized interview and physical examination assessing thrombotic and nonthrombotic APS manifestations and thrombosis risk factors. aPLs were detected in 16% patients and 5.6% controls (p = 0.035). LA was the most common aPL in patients (9%), followed by aβ2GPI (5%) and aCL (4%). Thrombotic events occurred in five patients [stroke in two, myocardial infarction in one and deep-vein thrombosis (DVT) in four], but in none of controls (p = 0.061). Mean age at time of stroke was 35years. Three patients with thrombotic events (including the two with stroke) had APS (Sydney's criteria) and were positive exclusively for LA. Comparison of patients with (n = 16) and without (n = 84) aPL revealed similar mean age, female predominance, and ethnicity (p > =0.387). Frequencies of livedo reticularis (25 vs. 4.8%, p = 0.021), stroke (12.5 vs. 0%, p = 0.024), and DVT (18.8 vs. 1.2%, p = 0.013) were significantly higher in APL + patients. Conversely, frequencies of hypertension, dyslipidemia, diabetes, obesity, smoking, sedentarism, and hormonal contraception were similar in patients with or without aPL (p ≥ 0.253). Our study identified LA as an important marker for APS in pSS, particularly for stroke in young patients, warranting routine evaluation of these antibodies and rigorous intervention in modifiable risk factors.

Anticardiolipin and anti-β2 glycoprotein-I antibodies patients with breast carcinoma: a pilot study

Thrombosis - the main manifestation of antiphospholipid syndrome (APS) - is at the same time observed in some patients with malignancies. Evaluation of prevalence of some antiphospholipid antibodies (aPL) in serum of patients with breast carcinoma and the possible correlation between aPL seropositivity and clinical symptoms. 40 patients with breast carcinoma and 38 patients with non-malignant diseases of breast were studied. Anticardiolipin antibodies (aCL) and antibodies to beta2 glycoprotein-I (anti-beta2GPI) were detected by ELISA. The aCL as well as anti-beta2GPI were positive in 1 patient with breast carcinoma, who at the same time presented with symptoms of APS. In the control group 2 patients were positive for anti-beta2GPI. We have not observed a difference of aPL prevalence between the group of patients with breast carcinoma and controls. The association of breast cancer and aPL seropositivity deserves further investigations.

Antiphospholipid antibodies in black south africans with hiv and acute coronary syndromes: prevalence and clinical correlates

BackgroundHIV infection is associated with a high prevalence of antiphospholipid antibodies (aPL) and increased thrombotic events but the aetiopathogenic link between the two is unclear.FindingsProspective single centre study from Soweto, South Africa, comparing the prevalence of aPL in highly active anti-retroviral therapy (HAART) naïve HIV positive and negative patients presenting with Acute Coronary Syndromes (ACS). Between March 2004 and February 2008, 30 consecutive black South African HIV patients with ACS were compared to 30 black HIV negative patients with ACS. The HIV patients were younger (43 ± 7 vs. 54 ± 13, p = 0.004) and besides smoking (73% vs. 33%, p = 0.002) and lower HDL levels (0.8 ± 0.3 vs. 1.1 ± 0.4, p = 0.001) had fewer risk factors than the control group. HIV patients had a higher prevalence of anticardiolipin (aCL) IgG (47% vs. 10%, p = 0.003) and anti-prothrombin (aPT) IgG antibodies (87% vs. 21%, p < 0.001) but there was no difference in the prevalence of the antiphospholipid syndrome (44% vs. 24%, p = N/S) and aPL were not predictive of clinical or angiographic outcomes.ConclusionsTreatment naïve black South African HIV patients with ACS are younger with fewer traditional coronary risk factors than HIV negative patients but have a higher prevalence and different expression of aPL which is likely to be an epiphenomenon of the HIV infection rather than causally linked to thrombosis and the pathogenesis of ACS.

Vitamin D levels in Chinese patients with systemic lupus erythematosus: relationship with disease activity, vascular risk factors and atherosclerosis

To study the relationship of 25(OH)D(3) level with disease activity, vascular risk factors and atherosclerosis in SLE. Consecutive patients who fulfilled four or more ACR criteria for SLE were recruited for assay of 25(OH)D(3) level. Disease activity was assessed by the SLEDAI and physicians' global assessment (PGA). Patients with vascular risk factors were screened for atherosclerosis at the coronary or carotid arteries. Correlation between 25(OH)D(3) levels and SLEDAI scores was studied by linear regression. The link between vascular risk factors, atherosclerosis and vitamin D deficiency was also examined. A total of 290 SLE patients were studied [94% women; mean (s.d.) age 38.9 (13.1) years; disease duration 7.7 (6.7) years; 78% patients had clinical or serological lupus activity]. Two hundred and seventy-seven (96%) patients had vitamin D insufficiency [25(OH)D(3) < 30 ng/ml] and 77 (27%) patients had vitamin D deficiency (<15 ng/ml). Levels of 25(OH)D(3) correlated inversely with PGA (β -0.20; P = 0.003), total SLEDAI scores (β -0.19; P = 0.003) and subscores due to active renal, musculoskeletal and haematological disease. Subjects with vitamin D deficiency had significantly higher total/high-density lipoprotein (HDL) cholesterol ratio [3.96 (2.94) vs 3.07 (0.80); P = 0.02] and prevalence of aPLs (57 vs 39%; P = 0.007). Of 132 patients, 58 (44%) with vascular risk factors screened were positive for subclinical atherosclerosis. No association could be demonstrated between 25(OH)D(3) level and atherosclerosis, which was mainly associated with increasing age, menopause, obesity and hyper-triglyceridaemia. In this large cross-sectional study of SLE patients, 25(OH)D(3) level correlates inversely with disease activity. Vitamin D deficiency is associated with dyslipidaemia. In patients with vascular risk factors, subclinical atherosclerosis is not associated with hypovitaminosis D.

Characterization of antiphospholipid antibodies in chronic hepatitis B infection

BackgroundMany infections are associated with antiphospholipid antibodies (aPLs). The purpose of this study was to investigate the prevalence, persistence, clinical significance, and characteristics of aPLs in hepatitis B virus (HBV)-infected patients.MethodsThis study included 143 patients with HBV infection and 32 healthy individuals as controls. The presence of anticardiolipin antibodies (aCL Ab), anti-β2-glycoprotein I antibodies (β2GPI Ab), and lupus anticoagulant (LA) was assessed.ResultsThe total prevalence of aPLs in HBV-infected patients was 12.6% (18 of 143). Of these 18 patients, 15 had low to medium titers of aCL Ab (10 with IgM, 4 with IgG, and 1 with both isotypes). β2GPI Ab and LA were detected in 3 (2.1%) and 2 (1.4%) patients with HBV infection, respectively. In follow-up specimens from 14 patients with elevated levels of aCL Ab or β2GPI Ab, 10 (71.4%) showed the persistent presence of aPLs. No clinical manifestations related to aPLs were identified.ConclusionIn HBV-infected patients, the most frequently detected antiphospholipid antibodies were IgM aCL Ab, which have a weak association with the clinical manifestations of APS. Unlike the transient presence reported for other infection-associated aPLs, most aPLs were persistently detected over a 12-week period in patients with HBV infection.

Prevalence and Clinical Associations of Lupus Anticoagulant, Anticardiolipin Antibodies, and Anti-beta2-glycoprotein I Antibodies in Patients with Systemic Lupus Erythematosus

The presence of antiphospholipid antibodies (aPLs) is associated with the clinical features of antiphospholipid syndrome (APS), which comprises venous and arterial thrombosis and pregnancy loss, and systemic lupus erythematosus (SLE). The prevalence of aPLs has been reported to be different in patient populations affected by either of these conditions. We performed a retrospective study to evaluate the prevalence and clinical associations of aPLs, including lupus anticoagulant (LAC), anticardiolipin (aCL), and anti-beta2-glycoprotein I antibodies (anti-beta2-GPI) in a cohort of Korean patients with SLE. This study included samples from 88 SLE patients for whom aPL testing had been advised between June 2006 and July 2009 at the Dong-A University Hospital. Serum and plasma samples were tested for LAC, aCL (IgG, IgM), and anti-beta2-GPI (IgG, IgM) antibodies. Clinical data from patients were obtained from a review of medical records. LAC was the most common (34.1% of total patients, 30/88) antibody, followed by IgM aCL (31.8%, 28/88), IgG aCL (18.2%, 16/88), and IgM and IgG anti-beta2-GPI (both 5.7%, 5/88 each). Positivity for LAC was strongly associated with venous/arterial thrombosis (P=0.002). LAC was the most common antibody detected in Korean SLE patients and is shown to have a significant association with the presence of venous/arterial thrombosis. The measurement of LAC may be clinically useful in identifying patients with SLE who are at a high risk for venous/arterial thrombosis.

Presence of low titre of antiphospholipid antibodies in cancer patients: a prospective study

Antiphospholipid antibodies (aPL) represent a well-defined risk factor for thrombotic events. aPL have been observed in the plasma of cancer patients, but the role and clinical relevance of aPL in this clinical setting is still unclear. This is a prospective cohort study whose aims were to: (1) compare the prevalence of aPL antibodies in cancer patients at diagnosis to matched control subjects; (2) compare thrombosis-free survival and overall survival in aPL positive and aPL negative cancer patients. One hundred and thirty-seven patients were enrolled upon a diagnosis of cancer, and were screened for lupus anticoagulant (LA), anticardiolipin antibodies, and anti-beta2 glycoprotein I antibodies (IgG and IgM). Two years of follow-up were scheduled. Low-titre aPL antibody positivity was found in 33 patients (24%), and in 6 controls (4.3%; P < 0.0001). During follow-up, nine patients developed a symptomatic, objectively confirmed, thromboembolic event. One thrombotic event was observed among the 33 aPL positive patients (3%), and 8 among the 104 aPL negative ones (7.6%) (P = NS). During follow-up, 21 patients died, and among them, 3 (9.1%) were aPL positive and 18 (17.3%) were aPL negative (P = 0.39; C.I. 0.28-0.05). In conclusion, a high prevalence of low-titre aPL was found in cancer patients at diagnosis, but no statistical difference in thrombosis-free survival or in overall survival was observed between aPL positive and aPL negative patients.

Prevalence of antiphospholipid antibodies in Syrian patients with thrombosis.

Antiphospholipid antibodies (aPL) are a heterogeneous family of antibodies associated with thrombosis and other complications. To study the prevalence of aPL in patients with thrombosis at Aleppo University Hospitals, Syria. One hundred and fifty-seven patients with venous and arterial thrombosis and 63 healthy controls were studied. Anticardiolipin antibodies (aCL) and Lupus anticoagulant (LA) were determined. Thirty-four out of 157 (21.7%) patients with thrombosis had some type of aPL. aPL was also found in four healthy subjects (4/63=6.3%). Eighteen patients (11.5%) were positive for LA, 20 (12.7%) for aCL antibodies and 4 (2.6%) were positive for more than one aPL. Patients without risk factors for thrombosis and having positive aPL were 23/34 (67.7%). Fourteen out of 78 (17.9%) patients with arterial thrombosis, and 20/79 (25.3%) with venous thrombosis were positive for at least one aPL. Our study showed a significant prevalence of aPL in patients with thrombosis. It seems that aPL is a risk factor for venous and arterial thrombosis, especially in patients with no conventional risk factors.

Comment on: Prevalence, serological features, response to treatment and outcome of critical peripheral ischaemia in a cohort of lupus patients: reply

SIR, We read with great interest the description of digital gangrene in lupus patients in an Indian population described by Rajasekhar et al. [1] in response to our recent publication in Rheumatology [2]. As the authors point out, the prevalence of aPLs was higher in our studies than in theirs and probably explained why they have managed to treat their patients relatively successfully using quite intense immunosuppression (monthly pulses of intravenous cyclophosphamide for 6 months) in contrast to our preference for intensive prostaglandin therapy. They suggested that immunosuppressive intravenous prostaglandins may not be necessary, as initial management of gangrene in lupus and if there are good grounds for believing that vasculitis alone in the absence of any accompanying thrombosis is thought to be the culprit, dispensing with prostaglandins may be an option. However, in reality, pre-gangrenous and, indeed, gangrenous lesions, due to digital ischaemia may develop with remarkable rapidity and certainly whilst waiting for results of blood tests, including aPLs, to come back from the laboratory, we would strongly advocate the use of intense intravenous vasodilatation if there is any doubt as to the underlining cause.

Prevalence and significance of antiphospholipid antibodies in selected at-risk obstetrics cases: A comparative prospective study

SummaryIn a prospective comparative study we screened 112 women with a past history either of pre-eclampsia, eclampsia, recurrent abortion, IUGR, IUFD or abruptio placentae, with no apparent aetiology and a demographically matched cohort of 106 women having a past history of uncomplicated pregnancy outcome for the presence of antiphospholipid antibodies (aPL) and their significance. In the former group, the prevalence of aPL ranged from 10–46.87% compared with 8.49% in the later group. In women with the presence of aPL, the incidence of pre-eclampsia, early onset pre-eclampsia and abruptio placentae were 25%, 14.58% and 18.75%, respectively. In the same group, the abortion rate was 25% and live-birth rate was 64.58% with IUFD rate of 10.42%. Fetal morbidity rates were also higher in the mothers with aPL positivity, the incidence of IUGR was 27.08% and oligohydramnios was 33.33% in them. All these complications were statistically significant when compared with those of aPL negative mothers.

Migraine and Antiphospholipid Antibodies: No Association Found in Migraine-Discordant Monozygotic Twins

Migraine headache (with and without aura) is common in the general population and is known to be influenced by genetic factors with heritability estimates between 34-57%. Antiphospholipid syndrome (APS) is a hypercoagulable state characterized by clinical features including venous and arterial thromboses, pregnancy loss and migraine, and by association with antiphospholipid antibodies (aPL). Numerous small studies have investigated whether aPL are associated with migraine in the general population--with contradictory results. In this study, the question was addressed by studying the prevalence of aPL in members of monozygotic (MZ) twin pairs differing in their migraine status. Such twins provide a unique natural experiment, matched as they are for age, sex and genetic factors, and allow the role of environmental factors, such as aPL, to be determined. Despite 95% power to detect a difference of 0.59 IgG units per litre in anticardiolipin antibody IgG titres, no difference in prevalence of aPL could be detected in migraine-discordant MZ twins.

ORIGINAL ARTICLE: Recurrent Pregnancy Loss and Frequency of Eight Antiphospholipid Antibodies and Genetic Thrombophilic Factors in Czech Women

ProblemThe aim of this study was to investigate frequencies of eight antiphospholipid antibodies (aPLs) in serum, four genetic thrombophilic factors and their mutual relation in 206 patients with repeated pregnancy loss (RPL).Method of studyEnzyme‐linked immunosorbent assay was used for detection of aPLs against ph‐serine, ph‐ethanolamine, ph‐inositol, DL‐glycerol, phosphatidic acid, anti‐annexin V, cardiolipin, and beta2‐GPI. FV 1691G&gt;A (Leiden mutation), FII 20210G&gt;A mutation, MTHFR 677C&gt;T and MTHFR 1298A&gt;C variant genotypes were determined using a melting curve analysis of the PCR amplification product detected by the fluorescence resonance energy transfer. Genotypic distribution and allelic frequencies were calculated. Correlation between aPLs and thrombophilic factors was tested by chi‐square and Fisher exact test.ResultsOur results show significantly increased prevalence of aPLs against ph‐inositol (17–19.6% dependent on number of spontaneous miscarriages) and against ph‐serine (18–25%). aPLs in IgG prevail. In 96% of the studied group, at least one risk factor was found (either aPLs positivity or thrombophilic factor). Both aPLs and thrombophilic factors were present in 43%. In the group of women with three or more RPLs, strong positive correlation of aPLs positivity and thrombophilic risk factors was observed.ConclusionAntiphospholipide antibodies and genetic thrombophilic factors are important risk factors in the pathogenesis of RPL. Both autoantibodies against various kinds of phospholipides and genetic thrombophilic factors must be studied together in diagnosis of RPL for appropriate treatment.

Prevalence of antiphospholipid antibodies in patients with neurological symptoms

Objective and purpose Neurological involvement is a common feature of the antiphospholipid syndrome (APS). A variety of thrombotic and non-thrombotic manifestations may accompany the presence of antiphospholipid antibodies (aPL). Patients and methods We retrospectively reviewed the prevalence of aPL in a cohort of over 350 unselected patients from a neurological clinic and studied the neurological manifestations of APS. Results We found that within this cohort the prevalence of aPL was about 15%. Most of the patients with aPL suffered from strokes and transient ischemic attacks (TIA). One patient died from spinal infarction. Non-thrombotic manifestations also occurred in 40% of these patients, such as multiple sclerosis, chorea, seizures or cerebral malignancies. No significant correlations of the titres or different types of aPL and the type of the neurological symptoms could be found. In comparison to age and sex matched patients of the cohort where the presence of aPL could be excluded, the occurrence of non-thrombotic manifestations was significantly more frequent and varied in the group of patients with aPL. The higher incidence of stroke in the non-APS group could be explained by the significantly higher presence of other laboratory risk factors, mainly hypercholesterinemia. Conclusion This investigation indicates that aPL may play an important role in the etiology of various neurological syndromes.

Antiphosphatidylethanolamine antibodies in recurrent early pregnancy loss and mid‐to‐late pregnancy loss*

Associations have been reported between antiphospholipid antibodies (aPL), mainly anticardiolipin antibodies (aCL) and/or the lupus anticoagulant, and recurrent pregnancy losses (RPL). However, relatively few studies describing antiphosphatidylethanolamine antibodies (aPE) have been reported. We describe the prevalence of aPL to both cardiolipin and phosphatidylethanolamine in patients with RPL. Patients with recurrent early pregnancy losses (n = 145) and mid-to-late pregnancy loss(es) (n = 26) were screened for aPE and aCL. In patients with recurrent early pregnancy losses, prevalence of immunoglobulin G (IgG) aPE (17.9%, P = 0.001) and immunoglobulin M (IgM) aPE (12.4%, P = 0.01) was significantly higher than in the control group. In patients with mid-to-late pregnancy loss(es), prevalence of IgM aPE (19.2%, P = 0.008) and IgG aCL (23.1%, P = 0.02) was significantly higher than in the control group. Our data suggest that aPE may be a risk factor in patients with mid-to-late pregnancy loss(es) as well as recurrent early pregnancy losses.

Antiphospholipid antibodies in primary Sjögren's syndrome: prevalence and clinical significance in a series of 74 patients.

The aim of this study is to determine prevalence, clinical significance of antiphospholipid antibodies (aPL) including anticardiolipin antibodies (aCL), anti-beta2GP1 and lupus anticoagulant (LA) in a cohort of 74 patients with primary Sjögren's syndrome (pSS) according to revised European criteria. aPL were found in 25 (34%) patients; IgG in 23 (12 had low titres, six moderate titres and five high titres) and IgM in five (three and two had respectively moderate and high titres). Eight (11%) patients were found to have LA; anti-beta2GP1 antibodies were detected only in three (4%) patients. Only two patients with LA, aPL and beta2GP1 had recurrent venous thrombosis. One patient with moderate titres of aPL exhibited recurrent spontaneous foetal losses. Peripheral neuropathies without cryoglobulinemia were more frequent in the aPL group. Other systemic involvements of pSS were the same in both groups with or without aPL. Patients with aPL have more concurrent immunological diseases such as thyroiditis and primary biliary cirrhosis and a higher prevalence of hypergammaglobulinemia (P < 0.05). Even if aPL prevalence reached 30% in pSS, titres were usually low, with a close correlation with hypergammaglobulinemia but not with antiphospholipid syndrome, which is related to positivity of both LA and aPL.

Prevalence and isotype distribution of antiphospholipid antibodies in unselected Chilean patients with venous and arterial thrombosis.

Antiphospholipid antibodies (aPL) are a heterogeneous family of antibodies associated with thrombotic events and other complications. The objective of this study was to investigate the prevalence of aPL in a group of Chilean patients with thrombosis. Two hundred and twenty-six patients with venous and arterial thrombosis and 95 healthy controls were studied. Anticardiolipin (aCL), anti-beta(2 )glycoprotein I (anti-beta(2)GPI), and antiprothrombin (aPT) antibodies were determined. Eighty-eight out of 226 (38.9%) patients with thrombosis had some type of aPL. Fifty-seven patients (25.2%) were positive for aCL, 31 (13.7%) for aPT, and 14 (6.2%) for anti-beta(2)GPI antibodies. Twelve patients (5.3%) were positive for more than one aPL. IgG, IgM and IgA isotypes were observed in aCL, anti-beta(2)GPI, and aPT antibodies. Twenty-six out of 92 (28.3%) patients with venous thrombosis and 31/134 (23.1%) patients with arterial thrombosis were positive for aCL antibodies. With regard to the control group (4/95=4.2%), the odd ratios (OR) were 5.2 (1.3-19.8; p0.01) and 5.7 (1.6-22.3; p0.01), respectively. Additionally, we observed statistically significant OR with aPT and anti-beta(2)GPI antibodies; in the first, with venous and arterial thrombosis, and in the second, only with arterial thrombosis. Our results show a significant prevalence of aPL, predominantly aCL and aPT antibodies, in patients with thrombosis. Additionally, aCL and aPT antibodies appear to be a risk factor for venous and arterial thrombosis, and anti-beta(2)GPI antibodies appear to be a risk factor for arterial thrombosis.

Antiphospholipid antibodies in Chilean patients with systemic lupus erythematosus

Antiphospholipid antibodies (aPLs) are a heterogeneous family of antibodies found in autoimmune disorders, infectious diseases, and other situations. The presence of different aPLs has been associated with various clinical manifestations of the antiphospholipid syndrome (APS). The objective of this study was to investigate the prevalence of aPLs in a group of 90 Chilean patients with systemic lupus erytematosus (SLE) and 90 healthy controls. We measured anticardiolipin antibodies (aCLs), antiphosphatidylserine antibodies (aPSs), anti-β2 glycoprotein I antibodies (anti-β2GPIs), and antiprothrombin antibodies (aPTs) with an enzyme-linked immunosorbent technique using “in-house” assays. Fifty-four of 90 SLE patients (60.0%) had some type of aPL. Forty of 90 (44.4%) were positive for aCLs, 9 of 61 (14.8%) had aPSs, 21 of 90 (23.3%) had anti-β2GPIs, and 18 of 90 (20.0%) had aPTs. In the control group, prevalences were as follows: aCLs, 3.3%; aPSs, 1.1%; anti-β2GPIs, 1.1%; aPTs, 2.2%. In most cases, values were in the low-positive range. Of all aPL detected, 29.5% was of the IgG isotype, 37.5% IgM, and 33.0% IgA. We observed a correlation between aCLs and aPSs and of these antibodies with anti-β2GPIs and aPTs but not between anti-β2GPIs and aPTs. Our results show a high prevalence of aPLs in SLE patients. An association between different specificities and isotypes of aPLs was also observed. (J Lab Clin Med 2002;140:336-41)

Antiphospholipid antibodies and infertility

Antiphospholipid antibodies (aPL) are an established cause of recurrent pregnancy loss. As defective embryonic implantation is a common link between unexplained infertility and recurrent miscarriage, interest has focused on the potential relationship between aPL and implantation failure after in vitro fertilization and embryo transfer (IVF-ET). This review critically examines the published data to determine whether women undergoing IVF-ET should be routinely screened for aPL. Although most studies have reported an increased prevalence of aPL among women undergoing IVF-ET, prospective studies examining the effect of aPL on the outcome of IVF-ET demonstrate that these antibodies do not significantly affect either the implantation or ongoing pregnancy rates. The increased prevalence of aPL among women with infertility is therefore likely to be part of a generalized autoimmune disturbance associated with infertility. Hence routine screening for aPL among women undergoing IVF-ET is not warranted and therapeutic interventions should be used only in well designed randomized controlled trials.

Lack of association between antiphospholipid antibodies and thrombocytopenia in patients with Wegener's granulomatosis

Background and Objective: In patients with Wegener's granulomatosis (WG), thrombocytopenia is less common than thrombocytosis. An increased prevalence of antiphospholipid antibodies (aPL), which is associated with thrombocytopenia, has been noted in patients with WG. The aim of this study was to examine the relationship between thrombocytopenia and aPL in patients with WG. Methods: Thrombocytopenic episodes were searched for in a random sample of 83 patients with WG. Stored sera obtained during thrombocytopenia, which was defined as platelet count below 130 × 109/L, were examined by 2 different enzyme-linked immunosorbent assays (ELISA) for IgG and IgM anticardiolipin antibodies (aCL) and for IgG antiphosphatidylserine antibodies (aPS). Screening for lupus anticoagulant was performed by use of activated partial thromboplastin time (aPTT). Results were compared with the prevalence of aPL in 20 consecutive nonthrombocytopenic patients with WG. Results: Six cases with thrombocytopenic episodes were found in the group of 83 patients with WG. Increased IgG and IgM aCL were detected in 1 patient, who also had elevated IgG aPS. A positive test result solely for IgM aCL was found in another patient. These findings were consistent in both ELISA for aPL. Five patients were being treated with cyclophosphamide when thrombocytopenia occurred. In the group of nonthrombocytopenic patients with WG, elevated IgG aCL and IgG aPS were consistently detected in 1 patient in both ELISA. Three other patients had positive results in single tests, which were not confirmed by the second assay. In all patients, aPTT was normal. Conclusions: Thrombocytopenia is a rare finding in patients with WG. A similar prevalence of aPL in thrombocytopenic and nonthrombocytopenic patients with WG provides no evidence that aPL play a major role in the pathogenesis of these events. Thrombocytopenia in WG is more likely caused by the myelotoxic effect of preceding cyclophosphamide treatment. We found a frequency of aPL in WG that exceeds frequencies seen in the general population but does not approximate those detected in systemic lupus erythematosus and closely related disorders. Semin Arthritis Rheum 31:4-11. Copyright © 2001 by W.B. Saunders Company

Antiphospholipid antibodies and thrombophilic factors in giant cell arteritis

Objectives: To evaluate the prevalence of thrombophilic risk factors known to induce intravascular clotting and to assess their relationship with ischemic manifestations in giant cell arteritis (GCA). Methods: Eighty consecutive patients with established GCA were included: 36 with isolated temporal arteritis (TA), 14 with isolated polymyalgia rheumatica (PMR), and 30 with TA and PMR. Forty-four patients (67%) had ischemic phenomena due to GCA. Twelve patients (15%) had thrombotic events unrelated to GCA (6 strokes, 5 deep venous thrombosis, and 1 myocardial infarction). A control group of 100 age- and sex-matched individuals without autoimmune disease, bleeding disorders, thrombosis, or clinical picture of TA or PMR also was analyzed. All participants were tested for the antiphospholipid antibody (aPL) profile, protein C, protein S, antithrombin activity, factor V Leiden mutation, and prothrombin gene G20210A mutation. We also studied fibrinolysis parameters: plasminogen, tissue-type plasminogen activator (t-PA) antigen, t-PA activity, type-1 plasminogen activator inhibitor (PAI-1) antigen, PAI-1 activity, and the 4G/5G polymorphism of the promoter region of the PAI-1 gene. Results: Eleven patients (18%) tested positive for lupus anticoagulant, 24 (30%) for anticardiolipin antibodies, 9 (11%) for anti–β2-glycoprotein I antibodies, and 29 (36%) for antiprothrombin antibodies. No relationship was found between these autoantibodies and ischemic manifestations. None of the patients had decreased protein C, protein S or antithrombin activity. Two patients and 2 controls were heterozygous for factor V Leiden, and only 1 patient and 2 controls were heterozygous for the prothrombin gene G20210A mutation. No statistically significant correlation was found between any thrombophilic factor and GCA-related or GCA-unrelated ischemic events. Conclusion: GCA patients have a high prevalence of aPL that is not related to ischemic manifestations. Moreover, GCA-related or GCA-unrelated ischemic manifestations do not appear to be due to congenital thrombophilic risk factors. Semin Arthritis Rheum 31:12-20. Copyright © 2001 by W.B. Saunders Company