Thrombotic tendency in systemic lupus erythematosus

FcγRIIA expression accelerates nephritis and increases platelet activation in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory disease characterized by deposits of immune complexes (ICs) in organs and tissues. The expression of FcγRIIA by human platelets, which is their unique receptor for immunoglobulin G antibodies, positions them to ideally respond to circulating ICs. Whereas chronic platelet activation and thrombosis are well-recognized features of human SLE, the exact mechanisms underlying platelet activation in SLE remain unknown. Here, we evaluated the involvement of FcγRIIA in the course of SLE and platelet activation. In patients with SLE, levels of ICs are associated with platelet activation. Because FcγRIIA is absent in mice, and murine platelets do not respond to ICs in any existing mouse model of SLE, we introduced the FcγRIIA (FCGR2A) transgene into the NZB/NZWF1 mouse model of SLE. In mice, FcγRIIA expression by bone marrow cells severely aggravated lupus nephritis and accelerated death. Lupus onset initiated major changes to the platelet transcriptome, both in FcγRIIA-expressing and nonexpressing mice, but enrichment for type I interferon response gene changes was specifically observed in the FcγRIIA mice. Moreover, circulating platelets were degranulated and were found to interact with neutrophils in FcγRIIA-expressing lupus mice. FcγRIIA expression in lupus mice also led to thrombosis in lungs and kidneys. The model recapitulates hallmarks of human SLE and can be used to identify contributions of different cellular lineages in the manifestations of SLE. The study further reveals a role for FcγRIIA in nephritis and in platelet activation in SLE.

Determinants of enhanced thromboxane biosynthesis in patients with systemic lupus erythematosus

OBJECTIVE

To evaluate the rate of thromboxane biosynthesis in patients with systemic lupus erythematosus (SLE), exploring the interplay between antiphospholipid antibodies (aPL) and 2 markers of endothelial perturbation: thrombin generation and platelet activation.

METHODS

A comparison of 11-dehydrothromboxane B2 (TXB2) excretion, which is a marker of in vivo platelet activation, aPL, von Willebrand factor (vWF) and tissue plasminogen activator (tPA), which are 2 circulating markers of endothelial perturbation, and plasma levels of the prothrombin fragment F1+2, which is a marker of thrombin generation, was performed in 40 SLE patients and 40 healthy subjects. Thromboxane metabolite excretion was also measured in 8 SLE patients before and after treatment with low-dose aspirin.

RESULTS

SLE patients had significantly higher 11-dehydro-TXB2 excretion, plasma F1+2, vWF, and tPA levels than controls. A statistically significant correlation was found between plasma levels of vWF and tPA and excretion of thromboxane metabolite. Moreover, significantly higher 11-dehydro-TXB2 was found in patients with aPL positivity and endothelial perturbation. Low-dose aspirin suppressed 11-dehydro-TXB2 by 80%, suggesting a predominant platelet source of enhanced thromboxane biosynthesis. After a median followup of 48 months, all SLE patients who experienced major cardiovascular events had thromboxane metabolite excretion, aPL positivity, and signs of endothelial perturbation.

CONCLUSION

We have characterized a sensitive marker of platelet activation, which is abnormal in SLE patients who were positive for aPL and endothelial perturbation. This analytical approach may help identify those patients at increased risk of thrombosis as potential candidates for antiplatelet therapy.

Antiphospholipid antibodies and reproduction: the antiphospholipid antibody syndrome

In women who have a diagnosis of APS (both clinical and laboratory criteria) the chance for successful pregnancy is reduced. In these cases, treatment appears to be a clear option, particularly in the case of prior thromboembolic events. The current preference of treatment for women with RPL and aPL antibodies is subcutaneous heparin and aspirin. This treatment should begin with a positive pregnancy test and continue postpartum. It is unclear, at this time, what treatment, if any, is required for women who do not meet all the criteria for diagnosis of APS, but who are known to have aPL antibodies. In some cases, these women were tested because of a prior false-positive test for syphilis, with subsequent identification of aPL antibodies. More recently, women undergoing IVF were tested and found to have an increased incidence of aPL antibodies. It was suggested that aPL antibodies are associated with infertility and failure to implant. However, a summary of published reports indicate that positive aPL antibodies in patients undergoing IVF do not influence ongoing pregnancy rates. This subject, however, remains an area of active investigation because aPL antibodies were shown to interact with the syncytiotrophoblast and cytotrophoblast layers and could, theoretically, after implantation.

Lupus anticoagulants and antiphospholipid antibodies

In recent years, clinical syndromes involving lupus anticoagulants and antiphospholipid antibodies have come into increasing clinical prominence. Since the discovery that most antiphospholipid antibodies require the presence of anionic phospholipid-binding proteins such as B2-glycoprotein I and prothrombin, a large number of studies have attempted to delineate the specificity of these antibodies. Several mechanisms have been proposed to explain the hypercoagulable state associated with these antibodies. This review attempts to summarize these data and the challenges that confront efforts to delineate the pathogenesis of the prothrombotic state associated with the presence of these antibodies.

Monoclonal IgM antiphosphatidylserine antibody reacts against cytoskeleton-like structures in cultured human umbilical cord endothelial cells

PROBLEM

It has been proposed that antibodies against phospholipid-dependent antigens (aPLs), induce recurrent pregnancy loss and thrombosis through modulation of endothelial cell function, yet aPLs have not been conclusively shown to bind with endothelial cells.

METHOD

Using indirect immunofluorescence we investigated the anti-endothelial cell reactivity of three monoclonal antibodies that differentiate between the phospholipids cardiolipin (CL) and phosphatidylserine (PS): BA3B5C4 (CL+/PS+); 3SB9b (CL-/PS+); and D11A4 (CL+/PS-). Cultured umbilical cord endothelial cells were prepared without fixation or with cold acetone fixation.

RESULTS

None of the aPLs reacted with endothelial cells prepared without fixation. 3SB9B reacted strongly with cytoskeletal-like components in acetone-fixed cells, whereas BA3B5C4 and D11A4 were unreactive. The cytoskeletal-like binding of 3SB9b was completely blocked by a monoclonal antibody against vimentin, whereas antibodies against tubulin or actin were not inhibitory. Lipid extraction of the cells destroyed the 3SB9b reactive antigen without affecting the reactivity of anti-vimentin.

CONCLUSION

These results suggest that phospholipid-dependent antigenic determinants are not expressed on the surface of resting endothelial cells but that a PS-dependent antigenic determinant is associated with endothelial cell intermediate filaments.

Effect of long-acting thromboxane receptor antagonist (BMS 180,291) on experimental antiphospholipid syndrome

Antiphospholipid syndrome (APS) is characterized by recurrent thromboembolic phenomena, recurrent fetal loss and thrombocytopenia associated with high titers of IgG anticardiolipin antibodies and/or lupus anticoagulant. There is an increased platelet aggregation in these patients and thus aspirin was found to be effective in abrogating some of the clinical findings. The purpose of this study was to employ the experimentally induced APS in mice infused with anticardiolipin antibodies, to study the effect of a thromboxane receptor antagonist (BMS, 180, 291) on the various overt manifestations of APS. Experimental APS was induced in pregnant female mice by iv infusion of a pathogenic anticardiolipin antibody (CAM). The mice were then treated daily with 300 micrograms/mouse of BMS. The study group and the untreated group were killed on day 17 of pregnancy. Live and absorbed fetuses and the mean weight of the placentae, fetuses and platelet counts were recorded. BMS treated mice had a significant reduction in fetal resorption rate from 45% to 19.8% and an increase in mean placental and embryo weights (182 vs 104, 1043 vs 721 mg, respectively). In parallel, an increase in platelet count (from 597,100 to 1075,000 platelets/mm3) and decrease in activated thromboplastin time (95 to 44s) was seen. It seems that thromboxane receptor antagonist may be effective in abrogating the diverse manifestations seen in APLS. Increased platelet aggregation may be one of the pathogenetic mechanisms in APS.

Antiphospholipid antibodies and thrombosis

Antiphospholipid antibodies are a diverse group of immunoglobulins initially thought to have specificity to phospholipid epitopes. It is apparent that autoimmune anticardiolipin antibodies require a serum cofactor beta-2-glycoprotein I (beta 2GPI) for their binding to phospholipids. Lupus anticoagulant also may bind to phospholipids by beta 2GPI or by prothrombin. The description of binding to protein-phospholipid epitopes may explain several perplexing features of these antibodies both in vitro and in vivo. Antiphospholipid antibodies have a well-established association with clinical disease--in particular thrombosis, thrombocytopenia and recurrent fetal loss. The mechanism of the predisposition to thrombosis seen with these antibodies is poorly understood. It has been suggested that they may cause endothelial dysfunction by causing increased tissue factor expression, by inhibiting prostacyclin secretion or by inhibiting fibrinolysis. Various platelet-activating activities have also been described. The evidence that antiphospholipid antibodies promote thrombosis by effects on endothelium or platelets is inconclusive. Inhibition of protein C activation, or of activated protein C action, has been demonstrated in vitro. A poor correlation between thrombosis in vivo and these inhibitory effects has been found. Beta-2-glycoprotein I has been identified as a cofactor for binding to phospholipid by thrombogenic anticardiolipin antibodies. That beta 2GPI may be a natural anticoagulant of importance remains to be proved. Inhibition by antiphospholipid antibodies of this anticoagulant function could explain the propensity to thrombosis seen in association with these antibodies.

Hypercoagulable states in patients with leg ischaemia

Hypercoagulable states are found in up to 10 per cent of patients with a history of unexplained venous thrombosis. To investigate the prevalence in arterial thrombosis, thrombophilia screening was performed on 124 patients who had previously undergone lower-limb revascularization, 45 claudicants and 27 controls. Of the patients who had undergone revascularization 40 per cent had a hypercoagulation abnormality (low levels of protein C, protein S and antithrombin III or presence of the lupus anticoagulant) in comparison with 27 per cent of claudicants and 11 per cent of controls (P < 0.01). Furthermore, patients who had suffered reocclusion after revascularization were significantly more likely to have a hypercoagulation abnormality than those who had not (P < 0.05), even if the occlusion had occurred more than 6 months previously. Lupus anticoagulant was the abnormality most frequently detected and, like low protein C levels, was found only in patients with peripheral vascular disease. It appears that hypercoagulable states are common in patients with arterial disease and may predispose to failure of revascularization.

The effect of aspirin on recurrent fetal loss in experimental antiphospholipid syndrome

PURPOSE

To evaluate the effect of aspirin treatment upon fetal loss in mice with experimental antiphospholipid syndrome (APLS).

MATERIALS AND METHODS

Experimental APLS was induced in pregnant mice by passive transfer of mouse monoclonal anticardiolipin antibody. The mice were treated with high (100 micrograms/d) or low (10 micrograms/d) dose of aspirin, using vitamin C (100 micrograms/d or 10 micrograms/d) as a control. The mice were assessed for the presence of lupus anticoagulants (prolonged aPTT), thrombocytopenia, degree of fetal resorption rate and mean embryo and placental weights.

RESULTS

The mice with APLS had a higher fetal resorption rate (45.7 +/- 12.2% vs 2.5 +/- 0.4%, P < 0.001), reduced placenta mean weight (104 +/- 8 mg vs 169 +/- 7 mg, P < 0.001), prolonged aPTT (94 +/- 14 sec vs 39 +/- 4 sec, P < 0.001), and reduced mean platelet count (597 +/- 186 x 10(3)/mm3 vs 847 +/- 51 x 10(3)/mm3, P < 0.001). The group of mice with APLS, who were treated with low-dose aspirin, had a lower resorption rate (11.1 +/- 9.3% vs 45.7 +/- 12.2%, P < 0.001), a higher placenta mean weight (178 +/- 8 mg vs 104 +/- 8 mg, P < 0.001), a higher mean embryo weight (1042 +/- 134 mg vs 721 +/- 91 mg, P < 0.001), and a lower aPTT (58 +/- 15 sec vs 94 +/- 14 sec, P < 0.001). Mice who were treated with high-dose aspirin also had a lower resorption rate, although not as much as in the low-dose aspirin group (34.2 +/- 12.7% vs 45.7 +/- 12.2%, P < 0.001).

CONCLUSION

Aspirin, especially in low dose, has a protective effect against obstetrical complications associated with experimental APLS.

Intravenous immunoglobulin treatment for recurrent abortions caused by antiphospholipid antibodies

There is an association between the presence of antibodies that bind to anionic phospholipids and the occurrence of repeated spontaneous abortion. Many uncontrolled studies have reported favorable pregnancy outcome in women treated with steroids, low-dose aspirin, heparin, or their combination. Similarly, treatment failures have been reported with most of these therapeutic regimens. Immunoglobulins play a central role in immune regulation. A wide spectrum of human diseases are associated with decreased or abnormal regulation of Ig levels. Recently, IV preparations of Ig have become available for clinical use, including treatment of patients with recurrent abortions and high levels of antiphospholipid antibodies. The effectiveness of this new mode of therapy can be related to several immunological mechanisms such as blockade of antibody binding to receptors on macrophages, increase in T suppressor cells, or decrease in antibody synthesis. The latter effect may be mediated by anti-idiotypic antibodies in the Ig preparation. Determination of dosage of IV Ig, duration of treatment, and treatment intervals are all empirical in patients with recurrent abortions and high levels of antiphospholipid antibodies because antiphospholipid antibody levels are not useful for monitoring therapy. Although the data available at present are promising, additional randomized trials are needed to determine the efficacy of IV Ig in patients with immunological recurrent abortions.

Review of hypercoagulability syndromes: what the interventionalist needs to know

Although none of these syndromes are very common, they are nevertheless of sufficient prevalence to be identified on occasion in the practice of the busy interventionalist or surgeon. Furthermore, it is anticipated that many more specific hypercoagulability disorders will be identified in the future. Therefore, it is necessary for the nonhematologist practitioner to be aware of their existence and to know when to seek hematology consultation to appropriately evaluate suspected individuals. Several clinical indicators should raise one's index of suspicion. One should be concerned about the patient with a strong family history of recurrent arterial and/or venous thrombosis or a history of previous arterial and/or venous thromboemboli without predisposing factors. Laboratory screening should be initiated for the patient who has had thrombotic events occurring at unusual sites, such as the upper extremity or mesenteric venous circulations, or in young patients presenting with thrombotic events. Patients with chronic arteriosclerotic disease at a young age, with evidence of rapidly progressive atherosclerotic lesions, and especially those who experience early occlusion after uncomplicated surgical or endovascular procedures warrant evaluation. Furthermore, patients manifesting a resistance to therapeutic anticoagulation with conventional agents may also be affected by one of these disorders. Identification of an underlying hypercoagulability disorder will not only influence the decision to proceed with a therapeutic intervention for noncritical arterial insufficiency but will also dictate appropriate pharmacologic management of the hypercoagulable patient to reduce potential thrombotic complications when vascular interventions are performed.

Immunology and clinical importance of antiphospholipid antibodies

Having reviewed the literature on the association of aPL antibodies with clinical manifestations, it is clear that this group of autoantibodies are of considerable importance. The presence of aPL antibodies in some but not all individuals confers a risk of a clinical syndrome characterized by recurrent arterial or venous thrombosis, thrombocytopenia, hemolytic anemia, or positive Coombs' test, and in females, recurrent idiopathic fetal loss. In SLE, the risk is approximately 40%, compared with a risk of 15% in the absence of aPL antibodies. However, only one half of persons possessing these antibodies have SLE, and overall the risk is around 30%. In some circumstances, such as in chlorpromazine or infection-associated aPL antibodies, there appears to be no increased risk. At the other end of the spectrum are seen patients whose only clinical manifestations comprise features of this clinical syndrome, and this entity has been designated the primary antiphospholipid syndrome (PAPS). aPL antibodies are also important because they are not uncommon. They have been found frequently in women with idiopathic recurrent fetal loss (30%), in non-autoimmune patients with ischemic heart disease (20%), or venous thrombosis (up to 30%), or stroke (4-47%), and in chronic immune thrombocytopenia (30%). These autoantibodies can be detected using sensitive solid-phase immunoassays employing the CL antigen, or in appropriate coagulation tests to detect LA activity. These assays are simple to perform but require care in selection of the best test and in interpretation of results. Current tests do not distinguish between those persons at risk of the clinical events and those not at risk. Detection of specific isotypes (especially IgG) and antibody level may aid in such a designation. Treatment of aPL antibody-associated syndromes remains a controversial subject. Since thromboses are associated with significant morbidity and potential mortality, there is a good argument for long-term preventive antithrombotic therapy, at least for as long as the antibodies are detectable, in those patients in whom clinical complications have previously occurred. It is not generally recommended that this treatment be offered to individuals in whom aPL antibodies are detected but who have not suffered previous thromboses, since the risk of such events does not appear to be equal within a group of aPL antibody-positive persons. This particularly applies to pregnant women, since live births and uncomplicated pregnancies are observed regularly in the presence of aPL antibodies without specific treatment. A previous history of at least one unexplained, late fetal loss is considered a prerequisite before intervention in subsequent pregnancies.(ABSTRACT TRUNCATED AT 400 WORDS)

The 'antiphospholipid syndrome' and the 'lupus anticoagulant'

In recent years an association has been described between, on the one hand, an in vitro prolongation of phospholipid-dependent coagulation tests (the 'lupus anticoagulant') or the demonstration of antiphospholipid antibodies and, on the other, clinical events, particularly recurrent thrombosis (usually venous but sometimes arterial), thrombocytopenia, and also recurrent mid-term fetal loss. Other less well-documented associations with haemolytic anaemia, livedo reticularis, strokes and other neurological syndromes have been suggested. The antibodies are present temporarily in many infections, are usually of IgM isotype and thrombosis does not occur. However, they are persistently present and mainly of IgG isotype in a number of auto-immune disorders associated with thrombosis, in particular systemic lupus erythematosus, in which 50% of patients will show antibody of one isotype or another. The strongest association is with antinuclear factor-negative lupus and 'lupus-like' disorders in which a full diagnosis of classical lupus cannot be made. The clotting test abnormality and antiphospholipid antibodies may be found also in otherwise normal individuals suffering thrombosis or fetal loss--the so-called primary antiphospholipid syndrome. These data raise important questions for management, but many details are controversial despite a decade's work; this review examines the present position and outlines some of the difficulties, particularly from the point of view of nephrology and paediatrics.

Clinical and laboratory findings in patients with antiphospholipid antibodies and cerebral ischemia. The Antiphospholipid Antibodies in Stroke Study Group

We reviewed the clinical and laboratory data of 128 patients with cerebrovascular disease and antiphospholipid antibodies. Cases were evenly divided between men and women, and the mean age of the study group was 46 years. Cerebral infarction occurred in 97 patients, and transient hemispheric ischemic attacks without stroke were recorded in 19; 12 suffered ocular ischemia. Systemic lupus erythematosus was diagnosed in 16% of all cases. Histories of systemic thromboembolic events and recurrent miscarriages were noted in 14% of the patients and in 19% of the women, respectively. Evidence of cerebral infarction preceding the index event was present in 30% of cases. During a mean follow-up of 16 months, nine of 96 (9%) patients sustained new cerebral infarctions. Of 72 echocardiographic studies, 16 (22%) showed valvular abnormalities. Cerebral angiography detected intracranial lesions in 24 of 49 patients (49%). These data indicate that antiphospholipid antibodies can be identified in stroke patients without known autoimmune disorders. They also suggest that antiphospholipid antibody-associated cerebrovascular ischemia may be recurrent and often occurs in patients with systemic thromboembolic events. Our findings should help design a prospective clinical trial that will assess the risk of recurrent thromboembolism in this population, identify stroke risk factors, and address therapy.

Paraproteinaemias and platelet aggregation: role of whole blood aggregometry

Whole blood and optical platelet aggregation were measured in normals and in patients with paraproteinaemias; extent of aggregation was correlated with paraprotein concentrations in patients and in normals after addition of different doses of paraproteins; threshold aggregating concentrations of several agonists were also determined in whole blood and in PRP from both groups of subjects. The results indicate that patients with macromolecular monoclonal component bear a "hyperaggregable" state which can be probably ascribed also to plasma hyperviscosity and which is better detected with the impedance aggregometer.

The role of platelets in progressive glomerulosclerosis: mechanisms for intraglomerular platelet activation and pathogenetic consequences

Purkerson et al. have hypothesized that platelet aggregation and release reactions contribute to the progressive sclerosis of remnant nephrons. The suggested mechanism for platelet activation is disruption of endothelium by the high hydraulic pressures characteristic of remnant nephrons, with platelet exposure to basement membrane collagen. We herein postulate additional mechanisms whereby platelets might be activated in the microcirculation of remnant nephrons: (i) kinetic activation due to high plasma flow rates; (ii) close cell contact due to concentration of blood cells and platelets in the glomerulus; (iii) concentration of protein macromolecules that act as agonists for platelet release; (iv) glomerular release of saturated and monenoic fatty acids that stimulate platelet synthesis of thromboxane A2; (v) glomerular release of membrane-bound pro-coagulant factor, triggering a chain reaction that activates both platelets and the intraglomerular coagulation cascade. Platelet activation could play a pathogenetic role in many of the known derangements of structure and function in remnant nephrons. This paradigm may also be partially applicable to the glomerulosclerosis of diabetes mellitus.

[Comparative study of 2 common tests for lupus anticoagulant determination: critical analysis of the results observed in 21 patients]

The Schleider and/or the Exner test have been found positive in twenty-one patients; five of these patients suffered of systemic lupus erythematosus (SLE). The Quick time and the activated partial thromboplastin time are normal in 52% of the cases. 40% have a minor haemorrhagic diathesis, without other significant clotting defect and 30% have thrombo-embolic complications. The Schleider index is more often strongly positive (greater than 2) in these two groups. 58% have an anemia, 25% a mild thrombocytopenia not deep enough to explain an haemorrhagic tendency (from 90.000 to 140.000/mm3). Several auto-immune tests are frequently positive even without SLE. The Schleider test is positive in 86% of the cases and appears a little more useful for the diagnosis than the Exner test, which has a 71% positivity.

Evaluation of lupus anticoagulants: antiphospholipid antibodies, endothelium associated immunoglobulin, endothelial prostacyclin secretion, and antigenic protein S levels

Plasma samples from nineteen patients with well characterized lupus anticoagulants (LA) were evaluated using a series of test systems. An ELISA was used to determine if the plasmas contained antiphospholipid antibodies (APA); fifteen of nineteen LA plasmas contained APA, with five exhibiting IgG only, two exhibiting IgM, and eight plasmas containing both IgG and IgM. Anti-phosphatidyl serine (PS) was the predominant IgG specificity and all IgM APA-containing plasmas reacted with phosphatidyl inositol (PI). An ELISA was developed to determine if LA plasmas contained immunoglobulin which would associate with cultured human umbilical cord vein-derived endothelial cells (HUV); ten of nineteen plasmas contained endothelium associated immunoglobulin (EAI). There was significant concordance between the occurrence of EAI and IgM anti-PI. The occurrence of EAI or APA, either singly or in combination, did not correlate with a past history of thrombosis. Patient plasmas were incubated with HUV and examined for effects on HUV prostacyclin (PGI2) secretion; six plasmas significantly stimulated PGI2 secretion and one plasma was inhibitory. Finally, plasma levels of free and total antigenic protein S were determined by EID. Five plasmas contained significantly reduced levels of free antigenic protein S, and total antigenic protein S was reduced in ten plasmas. Patient histories were examined for evidence of thrombotic episodes; six patients had a history of either arterial or venous thrombosis, with five of these six patients having drug-induced LA. Thus, unlike previous studies, drug-induced LA were associated with thrombosis.

The lupus anticoagulant stimulates the release of prostacyclin from human endothelial cells

Decreased endothelial cell production of prostacyclin (PGI2) in response to the lupus anticoagulant has been previously demonstrated and postulated to have a causal relationship to the thrombotic events associated with the lupus anticoagulant. Five patients who exhibited the anticoagulant were studied in an effort to determine if a relationship exists between exposure of endothelial cells to the lupus anticoagulant and decreased production of PGI2. Human endothelial cells derived from human umbilical vein grown in culture were exposed to IgG fractions of patient plasmas containing the lupus anticoagulant. PGI2 released per 10(6) cells was determined by radioimmunoassay for 6-keto-PGF-1-alpha. The overall means for the patient and control groups are given by 47 pM/10(6) cells and 12 pM/10(6) cells respectively. This is a statistically significant difference (F = 10.65, p = 0.017) when the effects of different batches of endothelial cells and thrombin stimulation are adjusted for in the analysis of variance model. These results demonstrate that in this homologous human system exposure of endothelial cells to the lupus anticoagulant leads to stimulation rather than inhibition of PGI2 release.

Migraine and the lupus anticoagulant. Case reports and review of the literature

Lupus anticoagulants (LA) are antiphospholipid serum immunoglobulins generally associated with autoimmune conditions, especially systemic lupus erythematosus (SLE). They have recently been linked to thrombotic events, including stroke. A possible association of migraine with LA is now forwarded with the presentation of two cases and a literature review. Our two patients, both in their forties, had migrainous phenomena without SLE or thrombotic events. Eight other cases were found in the literature, suggesting more than a chance association. Relevance to migraine pathophysiology is discussed and may come from the ability of the LA to alter prostaglandins and platelet activity and to interact with neuronal phospholipids. Further, larger studies are needed to support this association.

'Lupus' anticoagulant and thrombosis of the hepatic veins (Budd-Chiari syndrome). Report of three patients and review of the literature

Three patients with Budd-Chiari syndrome in association with the 'lupus' anticoagulant are described. This anticoagulant was looked for in our patients with an otherwise idiopathic hepatic venous thrombosis because of the presence of a pronounced thrombocytopenia, a prolonged activated partial thromboplastin time or a history of repeated abortions and deep leg vein thrombosis, respectively. An active search for the 'lupus' anticoagulant should be performed to lower the percentage of apparently idiopathic cases of Budd-Chiari syndrome.

Recurrent cerebral infarctions in two brothers with antiphospholipid antibodies that block coagulation reactions

Inhibitors blocking coagulation reactions, often called lupus anticoagulants, are readily identifiable but rarely considered as risk factors for cerebral infarction. These inhibitors are inconsistently found in a number of diseases (often autoimmune) and after treatment with ceretain drugs and appear to be closely associated with, or identical to, antibodies to certain phospholipids. We have observed two brothers with these inhibitors who both experienced recurrent cerebral infarctions. Such familial occurrence has rarely been reported. In addition, some other family members were found to have depressed factor XII levels. Using the technique of double immunodiffusion, we found that the serum from these brothers formed precipitin lines against certain phospholipid substrates, lending further support to the antiphospholipid nature of this inhibitor.

Obstetric complications associated with the lupus anticoagulant

We identified eight patients with the lupus anticoagulant (an autoantibody acquired by some patients with systemic lupus erythematosus), by observation of an increased activated partial thromboplastin time and abnormal results on a tissue thromboplastin-inhibition test. The patients had experienced a total of 30 spontaneous abortions and fetal deaths in 31 previous pregnancies (96.8 per cent). During their next pregnancy, the patients were treated with 40 to 50 mg of prednisone per day and 81 mg of aspirin per day. The therapy shortened their activated partial thromboplastin times, produced normal values for tissue thromboplastin inhibition, and reduced the rate of pregnancy loss to 37.5 per cent. However, preeclampsia developed in the five patients who gave birth to live infants, and fetal growth retardation occurred in three cases. The corticosteroid and low-dose aspirin regimen appears to improve perinatal outcome in cases in which the mother has the lupus anticoagulant, but such practices as careful fetal surveillance and preterm delivery when appropriate are also important to successful obstetric management of such cases.

Functional significance of renal prostacyclin and thromboxane A2 production in patients with systemic lupus erythematosus

We have examined the urinary excretion of stable immunoreactive eicosanoids in 23 female patients with systemic lupus erythematosus (SLE), 16 patients with chronic glomerular disease (CGD), and 20 healthy women. SLE patients had significantly higher urinary thromboxane B2 (TXB2) and prostaglandin (PG) E2 excretion and significantly lower 6-keto-PGF1 alpha than did healthy women. In contrast, CGD patients only differed from controls for having reduced 6-keto-PGF1 alpha excretion. The group of SLE patients with active renal lesions differed significantly from the group with inactive lesions for having a lower creatinine clearance and urinary 6-keto-PGF1 alpha and higher urinary TXB2. Higher urinary TXB2 excretion was associated with comparable platelet TXB2 production in whole blood, undetectable TXB2 in peripheral venous blood, and unchanged urinary excretion of 2,3-dinor-TXB2. A significant inverse correlation was found between urinary TXB2 and creatinine clearance rate (CCr). In contrast, the urinary excretion of 6-keto-PGF1 alpha showed a significant linear correlation with both CCr and para-aminohippurate clearance rate (CPAH). In four SLE and seven CGD patients, inhibition of renal cyclooxygenase activity by ibuprofen was associated with a significant reduction in urinary 6-keto-PGF1 alpha and TXB2 and in both CCr and CPAH. However, the average decrease in both clearances was 50% lower in SLE patients than in CGD patients, when fractionated by the reduction in urinary 6-keto-PGF1 alpha or PGE2 excretion. We conclude that the intrarenal synthesis of PGI2 and TXA2 is specifically altered in SLE. Such biochemical alterations are associated with changes in glomerular hemodynamics and may play a role in the progression of SLE nephropathy.

Autoimmunity and pregnancy

The general effect of pregnancy on autoimmunity remains controversial. In the majority of cases, pregnancy may have no effect on the disease, while on other occasions, pregnancy induces exacerbations that may be especially pronounced in the immediate post-partum period. The reasons for this preponderance are still unclear. Another important aspect of autoimmune diseases during pregnancy entails the passive transfer of the disease into the fetal compartment. It seems that until the pathogenesis and a better specific therapy for autoimmune diseases are clearly defined, careful clinical and immunologic observation of each mother-infant pair will be invaluable.

Lupus anticoagulant in pregnancy

In a group of 10 women with circulating lupus anticoagulant 25 intrauterine deaths were previously documented in the nine multigravidae. The presence of lupus anticoagulant activity was confirmed by showing prolongation of the activated partial thromboplastin time and kaolin clotting time with failure of correction of the prolongation on incubation with normal plasma. A clinical diagnosis of systemic lupus erythematosus (SLE) was made in four women. Three had deep vein thrombosis in pregnancy, one chorea gravidarum while two had only recurrent fetal losses. All the women had positive antinuclear antibody tests and blood platelet counts less than 175 X 10(9)/l. Anti-smooth muscle antibody and VDRL tests were each positive in half the patients; anti-DNA antibody was present in two patients with clinically active SLE. In six pregnancies correction of the activated partial thromboplastin and kaolin clotting time was attempted using prednisone (40-60 mg/day); aspirin, 75 mg/day, was added. Five live infants were obtained, four by spontaneous delivery, when the restoration of the clotting abnormalities to normal was achieved. In one woman presenting with extensive deep vein thrombosis a live infant was delivered following therapeutic doses of heparin and low dose aspirin. Maternal lupus anticoagulant activity has major implications for pregnancy and should be excluded in women with a clinical suspicion of SLE, a positive antinuclear antibody test, thrombotic episodes, biologically false-positive VDRL and unexplained late or repetitive early fetal losses.

Cerebral infarction associated with lupus anticoagulants--preliminary report

Hypercoagulability may contribute to stroke in young adults. Lupus anticoagulants (LA) were identified in six patients (4%) of 145 young adults with cerebral infarction. The clinical features of the 6 patients in this survey plus an additional patient from another institution with LA-associated stroke are presented. Four had systemic lupus erythematosus and 3 had idiopathic LA; all had mild thrombocytopenia. In 2 patients, no other conditions associated with stroke were discovered after thorough evaluation. Recurrent arterial thrombosis occurred in 4 of 7 patients during an average of two years of follow-up. Evidence suggests that inhibition of prostacyclin formation may occur with LA, promoting a prothrombotic state.

Deficiency of a plasma factor stimulating vascular prostacyclin generation in patients with lupus nephritis and glomerular thrombi and its correction by ancrod: in-vivo and in-vitro observations

Glomerular thrombi occur frequently in active lupus nephritis. Their presence has been correlated with low platelet counts and with subsequent development of glomerular sclerosis. We have examined the plasma PGI2 generating capacity of 8 patients with active lupus nephritis with thrombi that were to undergo defibrination therapy with ancrod. PGI2 generation by these plasma samples was significantly decreased as compared both to normals and to 6 individuals with lupus nephritis and no glomerular thrombi. Significant improvement in the capacity to generate PGI2 was seen in the post-ancrod treatment plasma samples. the pathogenesis of this defect is discussed.

Stroke as an early manifestation of systemic lupus erythematosus

Both stroke and transient cerebral ischaemic attacks occurring in younger patients may be due to systemic lupus erythematosus. Other clinical features of the disease may be absent. Initially the ESR may be normal, as may serological tests. Seizures may occur at or near the time of the vascular events. Systemic lupus erythematosus may be the cause of an asymptomatic cerebral infarct or multi-infarct dementia.