Platelet and endothelial activation in catastrophic and quiescent antiphospholipid syndrome

Antiphospholipid antibodies (aPL) seem to induce a prothrombotic state by activating endothelium and platelets, but no studies have evaluated systematically the effects of aPL from patients with the antiphospholipid syndrome (APS) in quiescent versus catastrophic phase. Our aims were to evaluate the in vitro effects on platelet activation of anti-β2 glycoprotein I (anti-β2GPI) antibodiesisolated from APS patientin either quiescent or catastrophic phase and to investigate ex vivo platelet and endothelial activation in patients with quiescent or catastrophic APS. Anti-β2GPI antibodies were isolated from plasma of a pregnant woman in two different stages of APS (quiescent and catastrophic, respectively). They were co-incubated with washed platelets from healthy controls that were then challenged with TRAP-6 (thrombin receptor activating peptide 6) and the expression of P- selectin (P-sel) on platelets was assessed by flow cytometry. Moreover, plasma samples from six patients with quiescent, four with catastrophic APS and 10 controls were assessed for several markers of platelet and endothelial activation. The results showed that purified anti-β2GPI antibodies co-incubated with platelets enhanced TRAP-6- induced platelet P-sel expression. Notably, anti-β2GPI antibodies isolated during the catastrophic phase enhanced platelet P-sel expression more than antibodies isolated from the same patient in the quiescent stage of disease. Moreover, APS patients had significantly higher plasma levels of soluble (s) Psel, sCD40 ligand, soluble vascular cell adhesion molecule 1 and monocyte chemoattractant protein 1 than control subjects. In addition, sP-sel and von Willebrand factor activity were significantly higher during catastrophic than in quiescent phase.

Treatment of 139 pregnancies in antiphospholipid-positive women not fulfilling criteria for antiphospholipid syndrome: a retrospective study

OBJECTIVE

The effect of low-dose aspirin (LDA) on pregnancy outcome in antiphospholipid (aPL)-positive women not fulfilling the criteria for antiphospholipid antibody syndrome (APS) was evaluated retrospectively.

METHODS

We evaluated 139 pregnancies of 114 aPL-positive women not fulfilling the Sydney classification criteria for definite APS (104 treated with LDA, 35 untreated). Inclusion criteria consisted of (1) any titer of aPL and no previous pregnancy or no pregnancy losses (defined as aPL carriers); (2) any titer of aPL and 1 or 2 pregnancy losses before the 10th gestational week. No women had previous thrombosis. The rate of pregnancy loss, gestational age at delivery, and birth weight percentile were compared in the treated and untreated patients. Associations between clinical and laboratory characteristics and pregnancy outcomes were investigated.

RESULTS

The rate of pregnancy loss was low in both treated and untreated groups (7.7% vs 2.9%, respectively). There were no statistically significant differences in the rate of pregnancy loss, gestational age at birth, or birth weight percentile in the treated and untreated groups. There were significant associations between gestational age at birth ≤ 34th week and positivity for lupus anticoagulant (p = 0.025) and anti-ß2-glycoprotein I IgG antibodies at titers > 99th (p = 0.016).

CONCLUSION

LDA treatment does not appear to improve pregnancy outcome in low-risk women not fulfilling the criteria for APS. Because antibody profile seems to influence pregnancy outcome, further studies of patients stratified according to their antibody profile are warranted.

Secondary prevention in thrombotic antiphospholipid syndrome

Secondary prevention of venous thromboembolism in antiphospholipid syndrome (APS) is usually made using vitamin K antagonists (VKAs) to maintain an international normalized ratio (INR) between 2.0 and 3.0. The optimal intensity of anticoagulation was determined in two prospective randomized controlled trials, both excluding the benefit of more intense anticoagulation. The same regimen is also recommended in patients with APS and arterial thromboembolism as aspirin does not appear to protect against recurrences. The duration of treatment is usually indefinite because of a substantial risk of recurrence.

Circulating β2 glycoprotein I-IgG anti-β2 glycoprotein I immunocomplexes in patients with definite antiphospholipid syndrome

Beta2-glycoprotein I (β(2)GPI), a relevant antigen in Antiphospholipid Syndrome (APS), binds anionic macromolecules including heparin (Hep). A possible formation of ternary complexes between β(2)GPI, antibodies and Hep in APS is thus possible. The aim of this study was to evaluate Hep-β(2)GPI interaction in patients with APS. The affinity of Heps of different length, including unfractionated Hep (UFH), low-molecular weight Hep (enoxaparin) and pentasaccharide (fondaparinux), to human β(2)GPI was estimated by fluorescence spectroscopy, yielding dissociation constant (K(d)) values of 1.1, 24.0 and 89.4 µM, demonstrating that the longer UFH binds to β(2)GPI far more tightly than the shorter ones. Plasma and protein G-purified IgGs from eight patients with APS (i.e. five with thromboembolic disease and three with catastrophic APS), were fractionated by affinity chromatography using a Hep (UFH)-bound column, eluted with a linear NaCl gradient. For each chromatographic analysis, fractions were collected in the whole NaCl gradient and tested by ELISA for the presence of β(2)GPI and anti-β(2)GPI IgG. The results of Hep-affinity chromatography and ELISAs concurrently indicate that either β(2)GPI and anti-β(2)GPI IgG elute from the Hep column in the same chromatographic peak, at a retention time identical to that of the purified, isolated β(2)GPI, thus suggesting that circulating immunocomplexes containing β(2)GPI are present in patients with APS.

Interpretation of laboratory data and need for reference laboratories

A single positive laboratory test among those exploring the presence of antiphospholipid antibodies is not associated with thromboembolic events and does not identify patients with antiphospholipid syndrome. On the other hand, more than one laboratory test positive, and in particular all three tests positive, is strongly associated to thromboembolic events and identifies high risk patients. Triple positivity is in fact related to the presence of a specific anti-β2-glycoprotein I (anti-Domain I) antibody, also able to prolong coagulation tests. Monoclonal antibodies against Domain I with Lupus Anticoagulant activity might be candidate material for standardization of antiphospholipid assays. Much work remains to be done in this field.

Hypertension negatively affects the pregnancy outcome in patients with antiphospholipid syndrome

The impact of hypertension in the pregnancies from autoimmune patients is not unequivocally defined. We have prospectively followed 168 pregnancies from 135 patients from four Italian centres to verify the potential impact of hypertension in the antiphospholipid syndrome (APS). The rate of preeclampsia, mean neonatal weight and gestational age at delivery were significantly lower in patients with both APS and hypertension than in patients with hypertension or APS alone. This information may be relevant for counselling and care of these patients.

Risk-based secondary prevention of obstetric antiphospholipid syndrome

Treatment of pregnant women with antiphospholipid syndrome (APS) should be set apart from that from thrombotic APS patients. Patients with a history of pregnancy morbidity but no vascular thrombosis are usually treated with a prophylactic dose of heparin plus low-dose aspirin; whereas, those with previous vascular thrombosis alone or associated with previous pregnancy morbidity, are commonly treated with a therapeutic dose of heparin generally combined with low-dose aspirin. However, in about 20% of pregnant APS women these regimens fail. In this context, we conducted a case-control study on a large multicentre cohort of conventionally treated pregnancies to verify whether specific laboratory profiles and/or clinical characteristics are predictive of unsuccessful pregnancy outcome during conventional treatments. Multivariate analysis showed that pregnancy failure during conventional therapies was independently associated with a history of both thrombosis and pregnancy morbidity, the presence of systemic lupus erythematosus (SLE) or other systemic autoimmune diseases and triple antiphospholipid antibody positivity. With the aim to discover the most effective and safe treatments in high-risk pregnant APS women a large-scale multicentre study focusing on the effect of treatments on pregnancy outcome in women with APS and further risk factors for pregnancy failure has been designed.

Antiphosphatidylserine/prothrombin antibodies in primary antiphospholipid syndrome

Antiprothrombin (aPT) antibodies may be detected by an enzyme-linked immunosorbent assay (ELISA) using a purified antigen or a phosphatidylserine/prothrombin complex (aPS/PT). IgG/IgM antibodies directed against aPS/PT were assessed in 158 patients with primary antiphospholipid syndrome (PAPS). They were detected in 80/158 (50.6%) PAPS patients; IgG alone was positive in 12 (7.6%), IgM alone in 36 (22.8%), and both IgG and IgM isotypes in 32 (20.2%) PAPS patients. IgG and IgM aPS/PT were significantly associated with both vascular thrombosis and pregnancy morbidity. IgG aPS/PT was significantly associated with venous thrombosis ( p = 0.023), whilst IgG and IgM aPS/PT were associated with arterial thrombosis ( p < 0.001 and p < 0.001, respectively). Logistic regression analysis showed that IgM and IgG aPS/PT were independent risk factors for thrombosis (odds ratio (OR) 3.5 [95% confidence interval (CI) 1.6–7.9] and OR 4.1 [95% CI 1.4–11.7], respectively) and IgM aPS/PT was an independent risk factor for arterial thrombosis (OR 2.7 [95% CI 1.1–6.7]). In conclusion, these findings indicate that aPS/PT are clinically relevant in PAPS.

What have we learned about antiphospholipid syndrome from patients and antiphospholipid carrier cohorts?

Venous or arterial thrombosis or pregnancy morbidity in the presence of circulating antiphospholipid antibodies (aPL) define the antiphospholipid syndrome (APS). In terms of accepted APS criteria, aPL are detected by one coagulation test (lupus anticoagulant; LAC) and two immunoassays (anticardiolipin antibodies and anti-β2-glycoptrotein I antibodies). In patients with APS, a single positive test carries a much lower risk of thrombosis recurrence or new pregnancy loss than does multiple (or triple) positivity. The same holds true for aPL carriers, namely subjects with laboratory tests but without clinical criteria for APS. Thus, very different risk categories exist among patients with APS as well as in carriers of aPL. Triple positivity apparently identifies the pathogenic autoantibody (antidomain I-II of β2-glycoptrotein I); it is in this category of patients that trials on new therapeutic strategies should focus.

A combination therapy to treat second-degree anti-Ro/La-related congenital heart block. A strategy to avoid stable third-degree heart block?

While mainly based on the use of fluorinated steroids, there is no standard management of anti-Ro/La-related congenital heart block (CHB). This is a report concerning two consecutive cases of anti-Ro/La-related second-degree block treated with betamethasone (4 mg/day), weekly plasmapheresis, and intravenous immunoglobulins (IVIGs; 1 g/kg) administered every 15 days, a therapy that was begun shortly after CHB was detected and continued until delivery. The newborns were also treated with IVIG (1 g/kg) soon after birth and continued fortnightly until the anti-Ro/La antibody levels became undetectable. In both cases second-degree AV block reverted to a stable sinus rhythm with a first-degree atrioventricular (AV) block. Moreover, there was no recurrence of CHB when therapy was suspended, as confirmed by a 29 month and an eight month follow-up, respectively.

Risk factors for pregnancy failure in patients with anti-phospholipid syndrome treated with conventional therapies: a multicentre, case-control study

OBJECTIVE

To identify the risk factors associated with pregnancy failure in patients with APS treated with conventional therapy.

METHODS

A multicentre, case-control study was conducted to compare APS patients with successful and unsuccessful pregnancy outcomes. We retrospectively considered 410 pregnancies of women diagnosed with primary APS. The study focused on 57 unsuccessful pregnancies (considered the study population) and 57 successful pregnancies (considered the control population) matched for age and therapy. All the patients had been treated with conventional protocol treatments including low-dose aspirin and/or heparin. The clinical and laboratory features of the two groups of women diagnosed with APS were compared.

RESULTS

The independent risk factors for pregnancy failure were: (i) the presence of SLE or other autoimmune diseases [odds ratio (OR) 6.0; 95% CI 1.7, 20.8; P = 0.01]; (ii) history of both thrombosis and pregnancy morbidity (OR 12.1; 95% CI 1.3, 115.3; P = 0.03); and (iii) triple [Immunoglobulin (Ig) G/IgM aCLs plus IgG/IgM anti-β(2) glycoprotein I antibodies plus LA] aPL positivity (OR 4.1; 95% CI 1.0, 16.7; P = 0.05). APS patients diagnosed on the basis of a single positive test and/or history of pregnancy morbidity alone were generally found to have successful pregnancies.

CONCLUSION

It would seem from these findings that the risk of pregnancy failure in APS women planning to conceive can be stratified on the basis of some specific clinical and laboratory features.

Adjusted prophylactic doses of nadroparin plus low dose aspirin therapy in obstetric antiphospholipid syndrome. A prospective cohort management study

OBJECTIVES

Current guidelines for the treatment of patients with obstetric antiphospholipid syndrome (APS) recommend low dose aspirin (LDA) and prophylactic doses of low molecular weight heparin (LMWH). Most clinicians use a fixed dosage of LMWH in pregnant APS women despite the fact that there are no clinical trials establishing that fixed doses are more efficacious than adjusted ones in preventing pregnancy complications. The efficacy and safety of adjusted single daily doses of LMWH (nadroparin) combined with LDA have thus been evaluated in 33 consecutive pregnancies in women with diagnosed obstetric APS.

METHODS

LMWH doses were augmented as the pregnancies progressed and maternal/foetal weight increased. 70-80-90 U/Kg doses ranging between 3800 and 6650 U were administered daily during the first, second and third trimesters, respectively. LDA (100 mg/day) was also prescribed.

RESULTS

Pregnancy outcome was successful in 97% of the patients studied, who delivered, between the 29th and 41st weeks of gestation (mean 37.4 ±2.1 SD), 32 infants with a mean birth weight of 3084 g ± 514 SD. One woman (3%) experienced a spontaneous abortion at the 8th week of gestation.

CONCLUSIONS

The high live birth rate, the satisfactory mean gestational age and weight at birth and the absence of major pregnancy/neonatal-associated complications indicate that adjusted, once daily doses of LMWH together with LDA could be an efficacious treatment option for pregnant APS patients with no history of thrombosis.

Risk factors for a first thrombotic event in antiphospholipid antibody carriers: a prospective multicentre follow-up study

OBJECTIVES

To assess risk factors for a first thrombotic event in confirmed antiphospholipid (aPL) antibody carriers and to evaluate the efficacy of prophylactic treatments.

METHODS

Inclusion criteria were age 18-65 years, no history of thrombosis and two consecutive positive aPL results. Demographic, laboratory and clinical parameters were collected at enrolment, once a year during the follow-up and at the time of the thrombotic event, whenever that occurred.

RESULTS

258 subjects were prospectively observed between October 2004 and October 2008. The mean ± SD follow-up was 35.0 ± 11.9 months (range 1-48). A first thrombotic event (9 venous, 4 arterial and 1 transient ischaemic attack) occurred in 14 subjects (5.4%, annual incidence rate 1.86%). Hypertension and lupus anticoagulant (LA) were significantly predictive of thrombosis (both at p<0.05) and thromboprophylaxis was significantly protective during high-risk periods (p<0.05) according to univariate analysis. Hypertension and LA were identified by multivariate logistic regression analysis as independent risk factors for thrombosis (HR 3.8, 95% CI 1.3 to 11.1, p<0.05, and HR 3.9, 95% CI 1.1 to 14, p<0.05, respectively).

CONCLUSIONS

Hypertension and LA are independent risk factors for thrombosis in aPL carriers. Thromboprophylaxis in these subjects should probably be limited to high-risk situations.

Diagnostic accuracy of currently available anti-double-stranded DNA antibody assays. An Italian multicentre study

OBJECTIVES

An Italian multicentre study was promoted in order to assess the accuracy of four anti-double-stranded DNA (dsDNA) antibody assays for SLE diagnosis and monitoring.

METHODS

Two hundred and twenty-three patients with established SLE according to ACR classification criteria were enrolled from 9 centres. They included 59 patients at first evaluation (disease duration <12 months) and 164 with longer disease duration (median disease duration 120 months). The sera from 55 healthy subjects and 161 patients with rheumatic, infectious or neoplastic diseases were tested as controls. SLE activity was measured by ECLAM score. Anti-dsDNA antibodies were detected in serum by means of FarrzymeTM assay, fluoroenzymeimmunoassay (EliATM), Crithidia luciliae indirect immunofluorescence (CLIFT) or Farr radioimmunoassay (Farr). Cut-off values of quantitative assays were chosen by ROC curves analysis. Statistics were conducted by SPSS software package.

RESULTS

Sensitivity for SLE diagnosis ranged between 66% with Farrzyme to 95% with Farr, with about 90% specificity for all the methods tested. Farrzyme assay was more specific than the others towards patients with non-SLE connective tissue disease. The four methods were moderately concordant and correlated among them, all showing a positive association with active disease, renal or haematologic involvement, and a negative association with central nervous system disease. Whatever the assay used, anti-dsDNA antibody levels correlated with disease activity with r correlation coefficients ranging from 0.336 to 0.425 (p<0.0001).

CONCLUSIONS

The diagnostic accuracy for SLE of evaluated anti-dsDNA antibody assays is comparable and potentially improvabile especially in terms of specificity. The clinical adherence of the assays confirms the value of anti-dsDNA antibody for SLE monitoring.

[Clinical value of antibodies to lysobisphosphatidic acid in patients with primary antiphospholipid syndrome]

To assess the clinical value of anti-lysobisphosphatidic acid (anti-LBPA) antibodies in patients with primary antiphospholipid syndrome (APS), the sera of 140 primary APS patients were tested and compared with those of 70 control subjects affected with rheumatic systemic diseases (n. 24) or autoimmune thyroiditis (n. 46). Anti-LBPA anticardiolipin (aCL) and anti-beta2 Glycoprotein I (anti-beta2GPI) antibodies were determined using a "home made" ELISA method. Lupus anticoagulant (LA) was assessed using a series of clotting tests in accordance with the literature. IgG anti-LBPA was significantly prevalent in primary APS (p=0.000) with a sensitivity of 58.6% and a specificity of 92.9%. IgM anti-LBPA showed a significant frequency in primary APS (p=0.000) with a sensitivity of 28.6% and a specificity of 97.1%. Anti-LBPA's sensitivity and specificity for APS were lower or equal to those of aCL and anti-beta2GPI. The prevalence of anti-LBPA in the different clinical and laboratory subsets of APS was lower than those of aCL and anti-beta2GPI. It is interesting to observe that both IgG and IgM anti-LBPA were never found alone. The comparison between anti-LBPA and LA showed that the former had a higher sensitivity but a lower specificity. In conclusion, in view of our results anti-LBPA cannot at present be considered a further tool to be utilized to diagnose APS and to differentiate the different clinical and laboratory subsets of this disease.

Antiphospholipid syndrome: critical analysis of the diagnostic path

Antiphospholipid syndrome (APS) is diagnosed in the presence of vascular thrombosis or pregnancy morbidity occurring in patients with circulating antiphospholipid antibodies (lupus anticoagulant [LA] and/or IgG/IgM anticardiolipin [aCL] and/or IgG/IgM anti-beta2glycoprotein I [abeta2GPI] antibodies). Each test may identify different autoantibodies; a single test makes the diagnosis possible when positive on two or more occasions at least 12 weeks apart. However, single test positivity may be unrelated to pathogenic antibodies, which are now considered to be a subclass of abeta2GPI antibodies directed against the domain I of this protein. Conversely, all three positive tests identify a single class of abeta2GPI antibodies, thus identifying high-risk patients with APS.

[Confirmation of antiphospholipid antibody positivity: a year's results in a cohort of 113 patients]

OBJECTIVE

To evaluate the confirmation rate of antiphospholipid antibodies (aPL), to analyze their behaviour at confirmation time, and to study the clinical value of their confirmation.

METHODS

Blood samples from 380 subjects, enrolled in this study from June 1, 2007 to May 31, 2008, were tested for anti-cardiolipin (aCL) and anti-beta2glycoprotein (abeta2GPI) antibodies using an ELISA method and for Lupus anticoagulant (LA) using a series of clotting tests. The samples of the 113 subjects resulting positive at the first testing time were assayed again to confirm antiphospholipid positivity.

RESULTS

aPL positivity was confirmed in 67 out of the 113 subjects (59.3%). Medium-high antibody levels of all, except IgM aCL, aPL/ELISA had a significantly higher confirmation rate with respect to that in subjects with low levels. The confirmation rate in the category I antibody patients (multiple positivity) was higher than that in the category II antibody subjects (single positivity). LA positivity was confirmed only when it was associated to other aPL. The cut-off of 40 GPL produced a confirmation rate equal to that resulting from a 99th percentile cut-off. Confirmation of aPL positivity made it possible for us to confirm the diagnosis of antiphospholipid syndrome (APS) in 8 out of the 113 subjects originally resulting positive (7.1%). APS clinical features were vascular thrombosis in 4 of these and pregnancy morbidity in the other 4.

CONCLUSIONS

Our data emphasize aPL positivity confirmation selectivity, and medium-high antibody levels and category I antibodies (multiple positivity) had the best confirmation rates.

Failure of intravenous immunoglobulin to prevent congenital heart block: Findings of a multicenter, prospective, observational study

OBJECTIVE

Congenital heart block (CHB) is presumed to be caused by transplacental passage of maternal immunoglobulin against Ro and La ribonucleoproteins. The recurrence rate in subsequent pregnancies following the birth of a child with CHB is approximately 19%. The purpose of this study was to determine whether intravenous immunoglobulin (IVIG) therapy could prevent the development of CHB in the fetuses of high-risk pregnant women.

METHODS

A total of 24 pregnancies in 22 women who had a previous pregnancy in which CHB developed, were over the age of 18 years, were <12 weeks pregnant, and had anti-Ro, anti-La, or both antibodies were monitored in this multicenter, prospective, observational study. Fifteen patients received infusions of IVIG. The 9 pregnancies in the remaining 7 patients served as controls. IVIG was administered at a dose of 400 mg/kg at weeks 12, 15, 18, 21, and 24 of pregnancy. Echocardiograms were performed at least every 3 weeks from week 15 to week 30 of gestation. Electrocardiograms were obtained at birth. The outcome measure was the development of third-degree CHB detected by fetal echocardiogram.

RESULTS

CHB developed in 3 babies among the 15 pregnancies in the treatment group (20%) and in 1 baby among the 9 pregnancies in the control group (11%). CHB was detected at weeks 18, 23, and 26, respectively, in the 3 babies in the treated group and at week 19 in the baby in the control group. Three of the affected pregnancies ended in termination; 2 for reasons related to the fetal disease and 1 for reasons related to both maternal (severe pulmonary hypertension) and fetal disease (at 21 weeks of gestation).

CONCLUSION

IVIG at the dose and frequency used in this study was not effective as prophylactic therapy for CHB in high-risk mothers.

Clinical course of high-risk patients diagnosed with antiphospholipid syndrome

BACKGROUND

The characteristics and the clinical course of antiphospholipid syndrome (APS) in high-risk patients that are positive for all three recommended tests that detect the presence of antiphospholipid (aPL) antibodies have not been described.

METHODS

This retrospective analysis of prospectively collected data examined patients referred to Italian Thrombosis Centers that were diagnosed with definite APS and tested positive for aPL [lupus anticoagulant (LA), anti-cardiolipin (aCL), and anti-beta2-glycoprotein I (beta2GPI) antibodies]. Laboratory data were confirmed in a central reference laboratory.

RESULTS

One hundred and sixty patients were enrolled in this cohort study. The qualifying events at diagnosis were venous thromboembolism (76 cases; 47.5%), arterial thromboembolism (69 cases; 43.1%) and pregnancy morbidity (11 cases; 9.7%). The remaining four patients (2.5%) suffered from catastrophic APS. The cumulative incidence of thromboembolic events in the follow-up period was 12.2% (95% CI, 9.6-14.8) after 1 year, 26.1% (95% CI, 22.3-29.9) after 5 years and 44.2% (95% CI, 38.6-49.8) after 10 years. This was significantly higher in those patients not taking oral anticoagulants as compared with those on treatment (HR=2.4 95% CI 1.3-4.1; P<0.003). Major bleeding associated with oral anticoagulant therapy was low (0.8% patient/years). Ten patients died (seven were cardiovascular deaths).

CONCLUSIONS

Patients with APS and triple positivity for aPL are at high risk of developing future thromboembolic events. Recurrence remains frequent despite the use of oral anticoagulants, which significantly reduces the risk of thromboembolism.

The association between circulating antibodies against domain I of beta2-glycoprotein I and thrombosis: an international multicenter study

BACKGROUND

Diagnosis of the antiphospholipid syndrome (APS) is difficult as a result of limited specificity of existing assays for detecting clinically relevant antiphospholipid antibodies. Anti-beta2-glycoprotein I (beta 2GPI) antibodies play a central role in the disease process of APS.

OBJECTIVES

We have investigated the relation between antiphospholipid antibodies with specificity for domain I of beta 2GPI and thrombosis/pregnancy morbidity in an international multicenter study.

PATIENTS/METHODS

Four hundred and seventy-seven patients derived from nine different centres met the inclusion criterion of having anti-beta 2GPI antibodies in their plasma/serum. Clinical data and results of tests for lupus anticoagulant, anti-cardiolipin antibodies and anti-beta 2GPI antibodies were established at the different centres of inclusion. After being re-tested for the presence of IgG and/or IgM anti-beta 2GPI antibodies, the samples were tested for the presence of IgG-directed against domain I of beta 2GPI and results were correlated with the thrombotic and obstetric history.

RESULTS

Re-testing for the presence of anti-beta 2GPI antibodies resulted in inclusion of 442/477 patients. IgG class anti-domain I antibodies were present in plasma of 243/442 patients (55%). 201/243 (83%) had a history of thrombosis. This resulted in an odds ratio of 3.5 (2.3-5.4, 95% confidence interval) for thrombosis. Anti-domain I IgG antibodies were also significantly correlated with obstetric complications [odds ratio: 2.4 (1.4-4.3, 95% confidence interval)].

CONCLUSION

In this multicenter study, the detection of IgG antibodies that are directed against domain I of beta 2GPI proved to be more strongly associated with thrombosis and obstetric complications than those detected using the standard anti-beta 2GPI antibody assay.

Congenital heart block not associated with anti-Ro/La antibodies: comparison with anti-Ro/La-positive cases

OBJECTIVE

To study anti-Ro/La-negative congenital heart block (CHB).

METHODS

Forty-five fetuses with CHB were evaluated by analysis of anti-Ro/La antibodies using sensitive laboratory methods.

RESULTS

There were 9 cases of anti-Ro/La-negative CHB; 3 died (33.3%). Only 3 (33.3%) were complete in utero and 5 (55.5%) were unstable. No specific etiology was diagnosed. Six infants (66.6%) were given pacemakers. There were 36 cases of anti-Ro/La-positive CHB. All except 2 infants (94.4%) had complete atrioventricular block in utero. Ten died (27.8%), one (2.7%) developed severe dilated cardiomyopathy, and 26 (72.2%) were given pacemakers.

CONCLUSION

Nine of the 45 consecutive CHB cases (20%) were anti-Ro/La-negative with no known cause. They were less stable and complete than the anti-Ro/La positive cases.

Systemic sclerosis and aortic valve stenosis: therapeutic implications in two cases of aortic valve replacement

Cardiac involvement is very frequent and underestimated in systemic sclerosis, but few reports have been published on the surgical treatment of patients with systemic sclerosis. We describe herein two cases of valve replacement because of aortic stenosis.

Increased apoptosis in circulating lymphocyte cultures of anti-RNA polymerase III positive patients with systemic sclerosis

The sera of 39 patients (38 women and 1 man), 16 with limited and 23 with diffuse clinical form of systemic sclerosis (SSc), were tested for anti-centromere (ACA), anti-topoisomerase I (ATA) and anti-RNA polymerase III (ARA) antibodies. The presence of apoptotic cells in cultures of circulating lymphocytes was investigated using the TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling) technique. ACAs were present in 16 (41%), ATA in 15 (38%) and ARA in 8 (21%) cases. The mean frequency of apoptotic lymphocytes was statistically higher in the ARA positive patients with respect to that in the control population (P < 0.001), in ACA (P < 0.001) and in the ATA (P < 0.001) groups. Moreover, apoptosis was distributed homogenously in ACA and ATA positive subjects, but not in the ARA patients. Our results show that there is an increase in apoptosis in the lymphocytes of ARA positive SSc patients.

Influence of different IgG anticardiolipin antibody cut-off values on antiphospholipid syndrome classification

BACKGROUND

While medium to high titers of anticardiolipin (aCL) antibodies, defined as >40 GPL units or >99th percentile, is a laboratory criteria for the 'definite' diagnosis of antiphospholipid syndrome (APS), agreement between the two cut-offs has not been validated.

OBJECTIVE

To validate the current aCL laboratory criterion by verifying the effect of the two cut-offs on APS classification.

PATIENTS/METHODS

Ninety aCL positive APS patients were selected on the basis of their GPL values above the 99th percentile (17.4 GPL), which was calculated by testing 100 age- and sex-matched healthy subjects.

RESULTS

A significant difference in the IgG positivity (P < 0.0001) was found between the APS laboratory profiles as 20 out of the 24 (83.3%) patients with single positivity (aCL alone), six out of the 23 (26.1%) with double positivity (aCL plus lupus anticoagulant or anti-beta(2)glycoprotein I), and none out of the 43 with triple positivity (aCL plus lupus anticoagulant and anti-beta(2)glycoprotein I) had titers between the 99th percentile and 40 GPL units. Moreover, the rate of aCL values between the 99th percentile and 40 GPL units was significantly higher (P < 0.0001) in patients with pregnancy morbidity (73.7%) as compared to those with vascular thrombosis (16.9%) and those with both conditions (16.7%).

CONCLUSION

The 99th percentile cut-off level seems more sensitive than the >40 GPL value for APS classification, as it includes subjects with aCL positivity alone as well as patients with pregnancy morbidity.

Risk factors for a first thrombotic event in antiphospholipid antibody carriers. A multicentre, retrospective follow-up study

OBJECTIVES

To asses risk factors for a first thrombotic event in antiphospholipid antibody (aPL) positive carriers and evaluate the efficacy of prophylactic treatments.

METHODS

Recruitment criteria were age 18-65 years, no history of thrombosis, positivity for lupus anticoagulant and/or IgG/IgM anticardiolipin antibody (aCL) on > or =2 occasions at least 6 weeks apart. Demographic, laboratory and clinical parameters were collected at enrolment and at the time of the thrombotic event.

RESULTS

370 patients/subjects (mean (SD) age 34 (9.9) years) were analysed retrospectively for a mean (SD) follow-up of 59.3 (45.5) months. Thirty patients (8.1%) developed a first thrombotic event during follow-up. Hypertension and medium/high levels of IgG aCL were identified by multivariate logistic regression analysis as independent risk factors for thrombosis. Thromboprophylaxis during high-risk and long-term periods was significantly protective.

CONCLUSIONS

Hypertension or medium/high titres of IgG aCL are risk factors for a first thrombotic event in asymptomatic aPL carriers and primary prophylaxis is protective.

Patients with primary antiphospholipid antibody syndrome and without associated vascular risk factors present a normal endothelial function

INTRODUCTION

Primary antiphospholipid antibody syndrome (PAPS) is characterized by venous or arterial thrombosis and positive antiphospholipid antibodies. It is controversial whether PAPS patients have early atherosclerosis. Endothelial dysfunction is an early event in the natural history of atherosclerosis. Aim of our study was to compare endothelial function of patients with PAPS and no associated risk factors with that of age- and sex-matched controls.

MATERIALS AND METHODS

Patients with PAPS, carefully selected to exclude all known risk factors for cardiovascular diseases, estrogen therapy, pregnancy, intake of drugs affecting endothelial function, vitamins or antioxidants, were included in a case-control study. Controls were age- (+/-5 years) and sex-matched subjects with the same exclusion criteria but without PAPS. Flow-mediated dilation of the brachial artery and some plasmatic markers of endothelial and platelet activation were measured. Measures are expressed as mean+/-SEM.

RESULTS

Twenty cases (mean age 42+/-4.0 years, 11 females) and 39 controls (mean age 41+/-2.9, 22 females) were studied. FMD was 5.7+/-0.8% in cases (95% CI: 4.1 to 7.3) and 6.8+/-0.5% (5.7 to 7.9) in controls (p=NS). Plasma von Willebrand factor was 128+/-11.3% and 134.2+/-16.1% in cases and controls, respectively (p=NS). Soluble P-selectin and soluble CD40L were 94.1+/-4.9 ng/ml and 0.7+/-0.1 ng/ml in cases and 87.7+/-4.0 ng/ml and 1.0+/-0.2 in controls, respectively (p=NS). In a substudy, circulating progenitor and mature endothelial cells were comparable between the two groups.

CONCLUSIONS

Endothelial function in patients with PAPS and no associated risk factors is similar to that of age- and sex- matched controls. These data suggest that the alterations leading to thrombosis in PAPS concern primarily the clotting system.

The antiphospholipid syndrome and infections in a child with trisomy 21

The relationship between infections and antiphospholipid antibodies or antiphospholipid syndrome is an intriguing question. A two and a half year old child with trisomy 21, who suffered three severe episodes of thrombosis each taking place after an infection, is described here. As high titres of IgG anticardiolipin (ACL) antibodies was registered during the second and third episodes, the antiphospholipid syndrome was suspected. IgM as well as IgG and IgA ACL antibodies have been described at different titres in a wide variety of infections, although they are not usually associated with thrombosis. In this particular case the timing of events and their association with high IgG ACL antibody titres seemed to implicate infection in the pathogenesis of the antiphospholipid syndrome. It can be hypothesized that some infections not only "trigger" antiphospholipid antibody production, but--in genetically predisposed subjects--can induce the clinical manifestations of the antiphospholipid syndrome.

[Digital ulcers in a cohort of 333 scleroderma patients]

Digital ulcers (DU) at the hands are one of the more frequent and severe complications in systemic sclerosis. Data on their prevalence and distribution in the different subsets of disease are variable in the literature. We studied the frequency of DU in a cohort of 333 scleroderma patients followed in the last 10 years in our Unit. DU have been recorded in 133 patients (39,9%), more frequently in males, in patients with cutaneous diffuse form of disease and in patients with anti-Scl70 ANA specificity. Complications of DU have been observed in 12,3% of cases. Surgery of the hands has been required in 8,7% of patients. The more effective treatment of DU are i.v. prostanoids, performed usually in day hospital, with high costs for the National Health Service. Recently the efficacy of bosentan, an oral receptor antagonist of endothelin, has been demonstrated, thus opening new perspectives in the treatment of DU in systemic sclerosis.

Unstabilized DNA breaks in lymphocytes of patients with different subsets of systemic sclerosis

The clastogenic effects on DNA, proven by the presence of micronuclei (MN) and the protective cellular mechanisms normally used to stabilize DNA breaks were investigated in three subsets of patients with systemic sclerosis (SSc). The frequency of MN found in cultures of peripheral lymphocytes in patients with anticentromere and antitopoisomerase I antibodies was significantly higher than that in the control group. The group with anticentromere antibody showed a significantly higher frequency of MN than did the subjects with antitopoisomerase antibody (4.22% versus 2.34%, P < 0.001). Patients with anti-RNA polymerase III, instead, had a low prevalence of typical micronucleated cells (0.98%), not significantly different from that of the healthy controls (0.82%). Moreover, when MN was characterized for the presence or absence of DNA fragments with free 3'-OH ends by digoxigenin-dUTP (DIG-dUTP) using terminal deoxynucleotidil transferase, its frequency was found to be increased in the groups with anticentromere and antitopoisomerase I antibodies with respect to that in the controls. The increase was significantly higher in the lymphocytes of the patients with anticentromere than in those with antitopoisomerase I antibody (35% versus 20.08%, P < 0.001). Nonetheless, the prevalence of unstable DNA fragments in patients with anti-RNA polymerase III antibody was low (2.05%) and not significantly different from that of the control group (1.18%). Our results indicate that there is a clastogenic effect on DNA and an interference in the protective cellular mechanisms normally stabilizing DNA breaks only in some subsets of SSc patients.