Anticardiolipin antibodies in patients from Malaysia with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is highly prevalent in Malaysia, which has a mixed population of Malays, Chinese, and Indians. A quantitative enzyme linked immunosorbent assay (ELISA) was used to determine anticardiolipin antibody (aCL) levels (total immunoglobulin, IgG, and IgM) in 200 patients with SLE (164 Chinese, 26 Malay, and 10 Indian) attending the University Hospital of Kuala Lumpur, Malaysia, and 103 matched controls. Only 33 (16.5%) of the patients had raised aCL levels; 26 had raised IgG aCL, five IgM aCL, and two both IgG and IgM aCL. There was a low prevalence of raised levels of aCL in the population studied, which was seen in conjunction with a rare occurrence of thrombosis. The classical association of high aCL levels with thrombocytopenia and recurrent abortions was noted, though not with cerebral disease. The low prevalence of aCL in this study population of mixed racial origin contrasts with findings in European patients with SLE and lends support to the influence of local factors, be they genetic or environmental, on the clinical manifestations of this disease.

t-PA, PAI, and protein C before and after vascular occlusion of the upper limb in patients with Raynaud's phenomenon

Tissue plasminogen activator (t-PA) and its inhibitor (PAI) were assessed in venous blood drawn before and after venous occlusion (bvo, avo) for 33 patients with Raynaud's phenomenon (RP), 14 with primary RP (PRP), 9 with suspected secondary RP (SSRP), and 10 with definite collagen disease and secondary RP (SRP). There were significant differences in PAI values avo between PRP (and controls), SSRP, and SRP. PAI activity decreased significantly avo only in controls and in PRP, and there was significant t-PA antigen elevation avo in the same groups. In addition, since PAI is neutralized by activated protein C (PC), both PC antigen and PC activity were assessed avo and bvo. PC Ag remained unchanged in all groups, with PC activity significantly lower than controls in SRP and SSRP. Finally the authors looked for interference of anticardiolipin antibodies (ACA) and lupus-like anticoagulant (LAC) with the PC system in collagen disease-associated RP. Specific IgG ACA were found in only 1 patient with SRP. In conclusion, there is an endothelial derangement, involving t-PA release and PAI, in SSRP and SRP patients. The reduced PC activity in these latter groups appears to be due to increased PAI influence rather than to ACA/LAC.

A "primary" thrombotic syndrome: absence of anti-phospholipid antibodies

A patient presenting fetal loss, livedo reticularis, severe migraine crises, myocardial infarction and thrombotic vasculopathy of both external iliac arteries is described. The serologic study showed absence of antiphospholipid antibodies (aPL), suggesting that in some cases the presence of these antibodies may be a consequence of tissue damage.

Anticardiolipin antibodies in unselected pregnant women. Relationship to fetal outcome

Anticardiolipin antibodies (ACLA) have recently been associated with adverse fetal outcome. The prevalence of elevated ACLA has not been studied in unselected pregnant women, however. Twelve hundred unselected pregnant women were screened for IgG ACLA using an assay standardized by the first international workshop on ACLA. Fifteen (1.25%) were positive for IgG ACLA (greater than 3 SD above the mean) but only 0.5% had moderate to high levels of IgG ACLA (greater than 5 SD above the mean). Low levels of IgG ACLA were not associated with increased risk of fetal loss; however, 50% of women with moderate to high levels of antibody had fetal wastage. These findings further support the association of significantly elevated levels of IgG ACLA with fetal loss.

Antiphospholipid antibodies and recurrent pregnancy loss

Women with antiphospholipid antibodies have a significant risk of reproductive failure and adverse pregnancy outcomes. The incidence of recurrent abortion, fetal death, and intrauterine fetal growth retardation is significant. Women with a history of recurrent abortion and unexplained fetal death or a history of recurrent thrombotic episodes should be screened for the presence of antiphospholipid antibodies. The benefit of routine screening of pregnant women for the presence of these antibodies has not been established, and the yield from such screening studies has been found to be low. No treatment regimen has eliminated fetal loss and adverse pregnancy events completely in women with the antiphospholipid antibody syndrome. Even when treatment is instituted, maternal and fetal status must be monitored closely. Management of such patients has not been standardized, and various treatment regimens have been found to be efficacious. Multicenter randomized treatment trials are currently underway, and standardization of therapy in these patients may be achieved.

Large vessel occlusion, cerebral infarction and thrombocytopenia in the "primary" antiphospholipid syndrome. Response to anticoagulation

A 65-year-old white female without lupus developed concurrent thrombocytopenia and disturbed arterial circulation to the brain and lower leg (a minor stroke and lower leg gangrene, necessitating amputation). Laboratory studies disclosed high levels of anticardiolipin antibodies. Anticoagulant treatment restored circulation in the remaining leg and also normalized platelet levels. This case emphasizes the importance of searching for anticardiolipin antibodies in unexplained thrombotic events.

Serial measurements of anticardiolipin antibodies in primary Sjögren's syndrome

Twenty-four out of 54 patients with primary Sjögren's syndrome (SS) were shown to be positive for IgG and/or IgM anticardiolipin antibodies (aCL). Extraglandular manifestations were related to the IgG-, but not to the IgM-aCL. Twenty SS patients were examined over a 3 year period. Of these, 6 displayed a marked increase in IgG- and IgM-aCL and, among them, 4 developed extraglandular manifestations of SS throughout the follow-up.

[Primary anti-phospholipid syndrome. Clinical experience at the Ignacio Chávez National Institute of Cardiology]

This paper describes 15 patients who had elevated IgG antibodies reactive with cardiolipin. Outstanding clinical features were: recurrent venous and/or arterial thrombosis--often extensive and severe--in 9 cases. Thrombocytopenia, in 11 cases and spontaneous recurrent fetal loss in 8 out of 10 females with marital life. In addition there were vasospastic/thrombotic features such as livedo reticularis, Raynaud's phenomenon and leg ulcers. Involvement of central and/or peripheral nervous system was present in 10 cases. Valvular heart disease was conspicuous, 10 out of 15 patients (66%) had organic lesions in both sides of the heart. There were also laboratory abnormalities such as prolonged partial thromboplastin time, false positive V.D.R.L., plasmatic anticoagulant activity and low incidence of antinuclear antibodies and rheumatoid factors. The clinical syndrome seems to be related to the presence of antibodies reactive with anionic phospholipids, although there is not formal proof of a direct cause effects relationship. Recognition of these distinct clinical entity is important, the use of simple anti aggregating agents like aspirine and careful anticoagulant therapy may modify the course of this newly recognized autoimmune condition.

Transient anticardiolipin antibodies, functional protein S deficiency, and deep vein thrombosis

A 30-year-old man presented with an episode of deep vein thrombosis. He was found to have primary antiphospholipid syndrome with anticardiolipin antibodies and protein S deficiency. All other investigations were negative. Three months later, anticardiolipin antibodies were negative and protein S levels were normal. The transient presence of anticardiolipin antibodies and functional protein S deficiency in this patient suggests a new mechanism for the association between anticardiolipin antibodies and venous thrombosis.

Antibody to cardiolipin causing hepatic infarction in a post partum patient with systemic lupus erythematosus

This is a case of a thirty one year old post partum patient, with SLE and antibodies to cardiolipin causing hepatic vascular thrombosis leading to infarction. No previous literature account is recorded.

Pregnancy complicated by antiphospholipid antibodies

The manifestations of antiphospholipid antibodies in pregnancy are multiple and include maternal arterial and venous thrombosis, spontaneous abortion, intrauterine fetal death, intrauterine growth retardation, and preeclampsia. Maternal complications may also arise in the puerperium with the development of an autoimmune pleuropulmonary postpartum syndrome. Currently, there is confusion in the literature regarding appropriate treatment of patients known to possess these antibodies. We have reported the case of a patient at 29 weeks' gestation who had elevated blood pressure, proteinuria, and early intrauterine growth retardation. Studies were positive for the presence of both lupus anticoagulant and anticardiolipin antibodies. After delivery, chest pain and a pleural effusion developed as further manifestations of the patient's autoimmune disease.

Anticardiolipin antibodies in migraine

Antiphospholipid antibodies have occasionally been observed in small series of migraine patients, possibly signalling an immunological pathogenesis in a subgroup. We have measured anticardiolipin antibody levels in a series of 94 migraine patients (35 patients having migraine with aura, 59 without aura), during acute attacks and between attacks. Platelet counts were normal and VDRL was negative in all patients. A low positive anticardiolipin antibody level was found in only one patient, which was negative six months later. There appears to be no association between the presence of anticardiolipin antibodies and migraine. Antiphospholipid antibodies are unlikely to have a material pathogenetic role. Statistically, the incidence of significantly raised anticardiolipin antibody levels in this group of patients does not exceed 4% at a 95% probability level.

Antiphospholipid, antinuclear, Epstein-Barr and cytomegalovirus antibodies, and soluble interleukin-2 receptors in depressive patients

To determine whether depression might be associated with serologic indices of autoimmune processes or active virus infections, we measured the following parameters in healthy controls, minor, simple major and melancholic patients: antiphospholipid (anticardiolipin, antiphosphatidylserine), antinuclear, and Epstein-Barr (EBV) and cytomegalovirus (CMV) antibodies. In addition, the soluble interleukin-2 receptor (sIL-2R) circulating levels in serum were measured and used as a marker of T cell activation. The anticardiolipin antibody titers were higher in melancholics than in healthy controls and minor depressives. Antinuclear antibodies were present significantly more frequently in depressed patients than in normal volunteers. The anticardiolipin and antinuclear antibody titers were significantly and positively intercorrelated. Depression is characterized by increased serum circulating levels of sIL-2Rs compared to the healthy state. Antinuclear-positive subjects exhibited significantly higher sIL-2Rs than those without detectable antinuclear titers. There was a positive correlation between anticardiolipin activity and sIL-2Rs. We found no evidence that depression is linked to EBV or CMV infection.

Cofactor dependent and cofactor independent anticardiolipin antibodies

Two distinct types of anticardiolipin antibodies are described, one of which requires the presence of a serum factor (cofactor) to bind cardiolipin in ELISA and liposome affinity systems. The second type does not require this cofactor. The requirement of a cofactor for the binding of some but not all anticardiolipin antibodies provides an explanation for the confounding variability of the results of assays for these antibodies. It also explains why blocking agents such as BSA and gelatin do not produce consistent results in this assay.

Serum factors affecting the specificity of anticardiolipin antibodies

The effects were investigated of two pretreatments of human serum and plasma test samples on their subsequent reactivity in the anticardiolipin antibody enzyme-linked immunosorbent assay (ACA-ELISA). The first treatment involved heat inactivation of test samples at 56 degrees C for 30 min, a process sometimes used to inactivate samples from suspected human immunodeficiency virus positive individuals. Such treatment significantly increased the IgG ACA unit/mL values of normal sera, but when this effect was examined further, it was found that the increase in binding occurred on both cardiolipin-coated and uncoated wells and was therefore non-specific. Heat inactivation of sera prior to ACA testing should therefore be avoided. The second treatment involved diluting immunoglobulin (Ig)G and IgM ACA-positive sera in normal human serum (NHS) or newborn calf serum (NCS); sera diluted in NHS showed a significant increase in titre, particularly IgM ACA-positive sera. This phenomenon was found to be due to a serum cardiolipin-binding cofactor which enhances antibody recognition. The cofactor is heat stable and is present in normal sera (male and female) and also in IgG ACA-positive sera. The binding of a human IgM monoclonal antibody to cardiolipin was not affected by the cofactor. The cardiolipin/cofactor complex may represent the optimal autoantigen/autoimmunogen and a re-appraisal, therefore, of the clinical relevance of antibodies to cardiolipin and other negatively charged molecules is warranted.

[The predictive value of the anti-cardiolipin antibody test for malignant tumors]

To determine the predictive value of the IgG anti-cardiolipin antibody test for malignant tumor, two groups of the patients of Kurume and Kyushu University Hospitals were examined by quantitative enzyme linked immunoadsorbent assay (ELISA) for their serum anti-cardiolipin antibodies. With the first group of the patients consisting of a mixture of benign diseases and malignant tumors, the antibody was positive at 57% (39/72). With the second, malignant tumor group, 38% (19/50) was positive for the antibody. When examined for the specificity of the antibodies by a binding inhibition assay, it was shown that the antibodies in the tumor patients were less specific to cardiolipin: antibodies to cardiolipin in tumor patients were blocked by the specific antigen, cardiolipin, in a lesser degree than those in the control syphilis patients, and highly cross-reacted with 2 related phospholipids, i.e., phosphatidyl glycerol and phosphatidic acid. These findings obtained in this study suggest that ELISA for cardiolipin has the value for the tumor diagnosis, supplementing already established assays.

Separation of lupus anticoagulant from anticardiolipin antibodies by ion-exchange and gel filtration chromatography

Separation of lupus anticoagulant from anticardiolipin antibodies in the serum of a patient containing both antibodies is described. A simple two-step procedure utilizing diethylaminoethylcellulose ion-exchange chromatography followed by Sepharose CL-4B gel filtration chromatography allowed the separation of IgM from IgG isotype. Lupus anticoagulant was found to be exclusively IgM, whilst anticardiolipin antibodies were IgG. This is apparently the first report that anticardiolipin antibodies and lupus anticoagulant can be different isotypes and adds to the increasing evidence that they are separate entities.

Hemolytic-uremic syndrome with anticardiolipin antibodies revealing paraneoplastic systemic scleroderma

Lupus anticoagulant was present in this case of paraneoplastic scleroderma revealed by hemolytic-uremic syndrome, suggesting that the autoantibody played a significant role in the sequence of events leading to anuria. Reviewing the literature we found several observations of paraneoplastic scleroderma, and in other series cases of scleroderma-linked (and in rare instances cancer-linked) antiphospholipid autoantibodies. Search for antiphospholipid antibodies should be considered in patients with systemic scleroderma as well as in patients with metastatic cancer. Presence of such procoagulant autoantibodies might predict future complications and should influence treatment strategy.

Antiendothelial cell antibodies in patients with the antiphospholipid syndrome

Antiendothelial cell antibodies (AECA) have been detected in 20 out of 30 patients (67%) with thrombosis associated with antiphospholipid antibodies. Seven patients had systemic lupus erythematosus and 13 had the "primary" antiphospholipid syndrome. Seven patients had both IgG and IgM AECA, 9 had IgG AECA only, and 4 had only IgM AECA. None of 30 control patients with thrombotic events not related to antiphospholipid antibodies had a positive titre of AECA (P less than 0.001). No correlation between AECA, antinuclear antibodies, anti-dsDNA antibodies, anti-neutrophil cytoplasm antibodies, precipitating antibodies to soluble nuclear and cytoplasmic antigens or complement components was found. The possible role of these AECA in the pathogenesis of thrombotic events is discussed.

Ig H and L chain contributions to autoimmune specificities

An Ig H chain expression vector has been constructed by using the V region of 3H9, an antibody that binds ssDNA, dsDNA, and cardiolipin. The H chain construct was transfected into six hybridoma cell lines expressing Ig L chains. All resulting H and L chain combinations had at least some affinity for ssDNA, whereas five also bound dsDNA to a similar degree as 3H9. The loss of dsDNA binding was correlated with a single amino acid difference between two V kappa 8 L chains. A further characteristic of 3H9, its immunofluorescent staining pattern, was shared by four of the recombinant antibodies, whereas its specificity for cardiolipin was shared with five. The transfections reported here show that a V kappa 3 L chain confers specificity for an RNA-associated epitope and that a V kappa 21E L chain prevents cardiolipin binding. These experiments suggest that the 3H9 H chain contributes essential determinants required for binding to DNA as well as cardiolipin but that L chains can modulate or prevent this binding. L chains may also expand the specificity of a recombinant antibody.

Detection of anticardiolipin antibody in patients with cocaine abuse

Anticardiolipin antibody, an immunoglobulin that binds negatively charged phospholipids, is considered to be an in vitro inhibitor of clot-based coagulation procedures. We adapted an enzyme immunoassay using stationary cardiolipin antigen to compare anticardiolipin antibody activity in the plasma of 44 cocaine abusers with its activity in the serum of 72 blood donors and a sample of 203 random specimens from healthy volunteers. Activity of 20 of the 44 abusers and 43 of 203 random specimens exceeded the donor control reference range. Patients using intravenous cocaine were more likely to have elevated activity than those who inhaled (P less than 0.05). Of 7 patients who had seizures or thromboembolic disorders, 5 were anticardiolipin antibody positive. Enzyme immunoassay may have predictive value for ischemic disease in cocaine abusers.

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)