Anti-Cardiolipin and Anti-beta2-Glycoprotein I Antibodies: Performance of New Commercial ELISA Kits

Antiphospholipid antibodies (aPL) are known to be pathogenic in experimental models and are predictive of thrombosis and miscarriages in patients, so it is important to correctly evaluate their presence for identifying patients at risk. Despite many years of work, the standardization of aPL ELISA remains an open problem, so evaluation of newly introduced commercial preparations is mandatory. A total of 80 sera were collected (10 primary antiphospholipid syndromes (APSs), 10 APSs associated with systemic lupus erythematosus, 20 infectious diseases, 20 rheumatoid arthritis and 20 normal blood donors) and tested for IgG/IgM anti-cardiolipin and anti-beta2GPI antibodies on commercial ELISA kits (ETI) by DiaSorin and on home-made ELISA. Both methods displayed good sensitivity and specificity for APS and were found to be concordant, especially in determining antibodies of IgG class.

The role of antibody polyspecificity and lipid reactivity in binding of broadly neutralizing anti-HIV-1 envelope human monoclonal antibodies 2F5 and 4E10 to glycoprotein 41 membrane proximal envelope epitopes

Two neutralizing human mAbs, 2F5 and 4E10, that react with the HIV-1 envelope gp41 membrane proximal region are also polyspecific autoantibodies that bind to anionic phospholipids. To determine the autoantibody nature of these Abs, we have compared their reactivities with human anti-cardiolipin mAbs derived from a primary antiphospholipid syndrome patient. To define the role of lipid polyreactivity in binding of 2F5 and 4E10 mAbs to HIV-1 envelope membrane proximal epitopes, we determined the kinetics of binding of mAbs 2F5 and 4E10 to their nominal gp41 epitopes vs liposome-gp41 peptide conjugates. Both anti-HIV-1 mAbs 2F5 and 4E10 bound to cardiolipin with K(d) values similar to those of autoimmune anti-cardiolipin Abs, IS4 and IS6. Binding kinetics studies revealed that mAb 2F5 and 4E10 binding to their respective gp41 peptide-lipid conjugates could best be defined by a two-step (encounter-docking) conformational change model. In contrast, binding of 2F5 and 4E10 mAbs to linear peptide epitopes followed a simple Langmuir model. A mouse mAb, 13H11, that cross-blocks mAb 2F5 binding to the gp41 epitope did not cross-react with lipids nor did it neutralize HIV-1 viruses. Taken together, these data demonstrate the similarity of 2F5 and 4E10 mAbs to known anti-cardiolipin Abs and support the model that mAb 2F5 and 4E10 binding to HIV-1 involves both viral lipid membrane and gp41 membrane proximal epitopes.

Mechanisms of ischemic stroke in HIV-infected patients

OBJECTIVE

To evaluate the types and mechanisms of stroke in a large population of HIV-infected patients.

METHODS

We reviewed records of consecutive HIV-infected patients with acute stroke admitted to a large metropolitan hospital between 1996 and 2004. Stroke mechanism was defined by consensus between two cerebrovascular neurologists using TOAST classification.

RESULTS

A total of 82 patients were included, 77 with ischemic stroke and 5 with intracerebral hemorrhage. Mean age was 42 years and 89% were African American. Previous diagnosis of HIV infection was documented in 91% and AIDS diagnosis in 80%. Mean CD4 count was 113 cells/mm(3) and 85% had CD4 count <200 cells/mm(3). A total of 61% of patients had received combination antiretroviral treatment (CART). The mechanism of ischemic stroke was large artery atherosclerosis in 12%, cardiac embolism in 18%, small vessel occlusion in 18%, other determined etiology in 23%, and undetermined in 29% (including 19% with incomplete evaluation). Vasculitis was deemed responsible for the stroke in 10 patients (13%) and hypercoagulability in 7 (9%). Protein S deficiency was noted in 10/22 (45%) and anticardiolipin antibodies in 9/31 (29%) tested patients. When comparing patients with large or small vessel disease (atherothrombotic strokes) vs the rest of the population, there were no differences in exposure to CART or CD4 count, but patients with non-atherothrombotic strokes were younger (p = 0.04). Recent cocaine exposure was less common among patients with atherothrombotic strokes (p = 0.02). Strokes were fatal or severely disabling in 35% of cases.

CONCLUSIONS

Stroke mechanisms are variable in HIV-infected patients, with a relatively high incidence of vasculitis and hypercoagulability. In our population of severely immunodepressed patients, exposure to combination antiretroviral treatment did not significantly influence the mechanism of stroke.

Antiphospholipid reactivity against cardiolipin metabolites occurring during endothelial cell apoptosis

We have recently shown that cardiolipin (CL) and its metabolites move from mitochondria to other cellular membranes during death receptor-mediated apoptosis. In this study, we investigate the immunoreactivity to CL derivatives occurring during endothelial apoptosis in patients with antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). We compared the serum immunoreactivity to CL with that of its derivatives monolysocardiolipin (MCL), dilysocardiolipin (DCL), and hydrocardiolipin (HCL) by means of both enzyme-linked immunosorbent assay and thin-layer chromatography (TLC) immunostaining. In addition, we investigated the composition of phospholipid extracts from the plasma membrane of apoptotic endothelial cells and the binding of patients' sera to the surface of the same cells by using high-performance TLC and immunofluorescence analysis. The average reactivity to MCL was comparable with that of CL and significantly higher than that for DCL and HCL in patients studied, both in the presence or in the absence of beta₂-glycoprotein I. Of relevance for the pathogenic role of these autoantibodies, immunoglobulin G from patients' sera showed an increased focal reactivity with the plasma membrane of endothelial cells undergoing apoptosis. Interestingly, the phospholipid analysis of these light membrane fractions showed an accumulation of both CL and MCL. Our results demonstrated that a critical number of acyl chains in CL derivatives is important for the binding of antiphospholipid antibodies and that MCL is an antigenic target with immunoreactivity comparable with CL in APS and SLE. Our finding also suggests a link between apoptotic perturbation of CL metabolism and the production of these antibodies.

Prevalence of antiphospholipid antibodies in Chilean patients with rheumatoid arthritis

Antiphospholipid (aPL) antibodies found in patients with autoimmune diseases are also detected in those with inflammatory diseases. The purpose of this study was to examine the prevalence of these antibodies in patients with rheumatoid arthritis (RA), and to evaluate the association of these antibodies with thrombosis and/or other clinical characteristics of this inflammatory disorder. Eighty-four patients with RA and 82 normal controls were studied. Anticardiolipin (aCL), anti-beta(2) glycoprotein I (anti-beta(2)GPI), and antiprothrombin (aPT) antibodies and the lupus anticoagulant (LA) activity were determined. Seven out of 84 (8.3%) patients were positive for aCL, six out of 84 (7.2%) for anti-beta(2)GPI, and six out of 84 (7.2%) for aPT, while in controls the overall prevalence of aPL antibodies was 3.6% (3 out of 82). All patients and controls were LA negative. There was no correlation between the presence of aPL with thrombosis and/or other clinical features of the antiphospholipid syndrome. We found aPL antibodies in 19.1% (16 out of 84) of the patients with rheumatoid arthritis and this prevalence was statistically higher than in normal controls (P<0.003). In this study, the presence of aPL antibodies was not associated with the development of thrombosis and/or thrombocytopenia. Whether the presence of aPL antibodies implies an increased risk for thrombosis and atherosclerosis in these patients should be studied further.

Different additional risk factors for cerebral infarctions associated with the factor V Leiden mutation in a family

Several cases with cerebral infarctions associated with the factor V Leiden mutation have been reported. However, bearing in mind the large number of asymptomatic individuals with the factor V Leiden mutation, additional risk factors for cerebral infarctions should be considered. In this report, two siblings with cerebral infarctions associated with a combination of heterozygous factor V Leiden mutation and different additional exogenous and endogenous thrombogenic risk factors are described. Respiratory problems in the perinatal period and increased lipoprotein (a) concentrations in the first patient and an episode of gastroenteritis from Shigella infection and persistent high titers of serum anticardiolipin and beta(2)-glycoprotein I antibodies in the second patient were recorded as additional thrombogenic risk factors. Furthermore, both patients were found to be heterozygous for the methylenetetrahydrofolate reductase gene C677T mutation. These findings suggest that even in the same family, different additional thrombogenic risk factors can be present in infants with cerebral infarctions associated with the factor V Leiden mutation. An extensive search of additional circumstantial and genetic thrombogenic risk factors should be useful for prophylaxis and prognosis of these infants with cerebral infarctions associated with the factor V Leiden mutation and of their related family members. To our knowledge, the second patient in this study is the first patient reported to have cerebral infarctions associated with the combination of the factor V Leiden mutation and persistent high titers of serum beta(2)-glycoprotein I antibodies.

Arginine residues are important in determining the binding of human monoclonal antiphospholipid antibodies to clinically relevant antigens

In the antiphospholipid syndrome (APS), antiphospholipid Abs (aPL) bind to anionic phospholipids (PL) and various associated proteins, especially beta(2)-glycoprotein I (beta2GPI) and prothrombin. In the present study, we show that altering specific Arg residues in the H chain of a human pathogenic beta2GPI-dependent aPL, IS4, has major effects on its ability to bind these clinically important Ags. We expressed whole human IgG in vitro by stable transfection of Chinese hamster ovary cells with expression plasmids containing different V(H) and V(L) sequences. V(H) sequences were derived from IS4 by altering the number of Arg residues in CDR3. V(L) sequences were those of IS4, B3 (anti-nucleosome Ab), and UK4 (beta2GPI-independent aPL). Binding of the expressed H/L chain combinations to a range of anionic, neutral, and zwitterionic PL, as well as prothrombin, beta2GPI, dsDNA, and chicken OVA, was determined by ELISA. Of four Arg residues in IS4VH CDR3 substituted to Ser, two at positions 100 and 100g, reduced binding to all Ags, while two at positions 96 and 97 reduced binding to beta2GPI but increased or decreased binding to different PL. Eleven of 14 H/L chain combinations displayed weak binding to OVA with Arg to Ser replacements of all four Arg residues enhancing binding to this Ag. Only one H/L chain combination bound neutral PL and none bound dsDNA; hence, these effects are particularly relevant to Ags important in antiphospholipid syndrome. We hypothesize that these four Arg residues have developed as a result of somatic mutations driven by an Ag containing both PL and beta2GPI.

[Von Willebrand factor activity in patients with systemic lupus erythematosus]

Eighty four SLE patients have been studied. The levels of Willebrand factor, total antibodies to cardiolipin class IgG, antibodies to D-DNA, total index of inflammatory process activity SLEDAI and other routine markers have been assessed. Endothelial-dependent vasodilatation of brachial artery and carotid intima-media thickness was found to exceed that of control group twice as much. The elevation of Willebrand factor is associated with increase in SLE activity and correlated with SLEDAI index, C-reactive protein level and total antibody content to IgG class phospholipids. The elevation of Willebrand factor activity is also associated with endothelial-dependent vasodilatation impairment in patients with high inflammatory process activity in particular.

A natural antibody to oxidized cardiolipin binds to oxidized low-density lipoprotein, apoptotic cells, and atherosclerotic lesions

OBJECTIVE

Cardiolipin (CL) is found in membranes of bacteria, in the inner membrane of mitochondria and in plasma low-density lipoprotein (LDL). Anticardiolipin antibodies (aCL) are associated with disease states, and we have suggested that many aCL bind to oxidized CL (oxCL) but not native CL. To determine the immunogenicity and origins of oxCL in vivo, we cloned a natural antibody to oxCL.

METHODS AND RESULTS

A monoclonal IgM antibody to oxCL (LRO1) was cloned from a nonimmunized LDLR-/- mouse. The V(H) sequence originated from the V(H)Gam3.8 germline with one nucleotide difference, and the Vkappa was 100% identical to Vkappa19-20 germline gene, making LRO1 a natural antibody. LRO1 bound specifically to oxCL and oxidized-LDL, but not to native CL or native LDL. LRO1 epitopes were demonstrated in apoptotic, but not in viable, Jurkat cells by flow cytometry, immunofluorescence and deconvolution microscopy. Human and rabbit atherosclerotic lesions contained LRO1 epitopes. Human LDL (n=113) showed LRO1 immunoreactivity, which correlated with aCL IgG titers (r=0.32, P=0.0004).

CONCLUSIONS

These data demonstrate that some aCL antibodies are highly conserved natural antibodies binding to oxCL in oxLDL, apoptotic cells, and atherosclerotic lesions. This suggests that oxCL is one of the pathogen-associated molecular patterns of innate immunity and gives insight into the pathogenic events of diseases with increased titers of aCL antibodies.

Specific phospholipid recognition by human immunodeficiency virus type-1 neutralizing anti-gp41 2F5 antibody

HIV-1 neutralizing monoclonal antibody (Mab) 2F5 recognizes a membrane-partitioning gp41 sequence. Just recently its capacity to react with cardiolipin has been demonstrated. Here, we have studied the specificity of Mab2F5-phospholipid interactions comparing partitioning into lipid bilayers with recognition of molecular species dispersed in solution. Using a liposome-based ELISA we demonstrate a preferential association with cardiolipin bilayers. When different soluble lysoderivatives were compared in their capacity to inhibit Mab2F5 binding to immobilized HIV-1 peptide epitope, only dilysocardiolipin resulted effective in blocking the process. Dilyso-cardiolipin also competed with native-functional gp41 for 2F5 recognition. Thus, our data support specific cardiolipin recognition by 2F5 that is not dependent on lipid bilayer assembly and involves the epitope-binding site. These findings might be of relevance for understanding the molecular basis of HIV-1 immune evasion.

False positive reactions in confirmatory tests for syphilis in presence of antiphospholipid antibodies: misdiagnosis with prognostic and social consequences

False-positive reactions in the Venereal Disease Research Laboratory test are well known, whereas a positive fluorescent treponemal antibody absorption assay is rarely thought to be a false positive. The non-recognition of serological false-positive tests for syphilis may have negative prognostic and social implications.

Anti-cardiolipin antibodies and overall survival in a large cohort: preliminary report

BACKGROUND

Anti-cardiolipin antibodies have been associated with both arterial and venous thrombosis, but their overall impact on all-cause or vascular mortality is unknown. In this study, we evaluated the influence of anti-cardiolipin antibodies on all-cause and vascular mortality.

METHODS

All individuals who fulfilled the inclusion criteria (completeness of data, no admission from an intensive care unit, unique identification with name and date of birth) and whose anti-cardiolipin antibodies were measured between October 2002 and February 2004 were included in this study (n = 4756; 64% female; median age, 46 years). Death/survival and cause of death were obtained from the Austrian Death Registry. The median observation period was 1.5 years, and the study comprised 7189 person-years.

RESULTS

During the study period, 184 patients (3.9%) died. There were no associations between either anti-cardiolipin IgM or IgG antibodies and both vascular death and noncancer mortality as outcome variables in a Cox regression analysis adjusted for age and sex. In contrast, the risk of cancer-related mortality was increased 2.6-fold.

CONCLUSIONS

Anti-cardiolipin antibodies are associated with cancer mortality, likely as an epiphenomenon of malignancy, but they are not predictive of vascular mortality or noncancer mortality. Hence, although a clear association between anti-cardiolipin antibodies and (mostly nonfatal) vascular events has been described in the literature, our data indicate that this finding is not necessarily associated with an increase in vascular mortality.

The association of anti-phospholipid antibodies with parity in placental malaria

Anti-phospholipid antibodies (aPL) are autoantibodies associated with both infections and the pathogenesis of certain pregnancy complications. In the latter, but not the former, aPL are dependent on a co-factor, beta(2) glycoprotein I (beta2GPI), which can also be used as an antigen for detection of such aPL in pregnancy. A cross-sectional study was carried out on serum samples from Kumasi, Ghana, to determine the occurrence and beta2GPI-dependence of aPL in placental malaria. Anti-cardiolipin, anti-phosphatidylserine and anti-beta2GPI enzyme-linked immunosorbent assays (ELISAs) were performed on sera from 103 HIV-non-infected gravid women. Placental malaria, both active and past infection, was diagnosed in 33/103 (32%) based on placental histology. In multiparae, beta2GPI-independent IgM antibodies to cardiolipin (P = 0.018) and phosphatidylserine (P = 0.009) were observed, which were most pronounced in past placental malaria infection. In primiparae, no association emerged between aPL and placental malaria. Trends for improved clinical parameters were identified in infected women with levels of anti-cardiolipin beyond the 99th multiple of the median for a healthy, non-malarious population. This study in placental malaria reports parity associations of beta2GPI-independent aPL profiles, and does not support a role for beta2GPI-dependent aPL. It is of significance in the context of the known parity differences in pregnancy malaria immunity.

Antiphospholipid antibodies bind ATP: a putative mechanism for the pathogenesis of neuronal dysfunction

Antiphospholipid antibodies (aPL) generated in experimental animals cross-react with ATP. We therefore examined the possibility that aPL IgG from human subjects bind to ATP by affinity column and an enzyme linked immunosorbent assay (ELISA). Sera with high levels of aPL IgG were collected from 12 patients with the antiphospholipid syndrome (APS). IgG fractions from 10 of 12 APS patients contained aPL that could be affinity-bound to an ATP column and completely eluted with NaCl 0.5 M. A significant (>50%) inhibition of aPL IgG binding by ATP 5 mM was found in the majority. Similar inhibition was obtained with ADP but not with AMP or cAMP. All the affinity purified anti-ATP antibodies also bound β₂-glycoprotein-I (β₂-GPI, also known as apolipoprotein H) suggesting that, similar to most pathogenic aPL, their binding depends on this serum cofactor. We further investigated this possibility and found that the binding of β₂-GPI to the ATP column was similar to that of aPL IgG in that most was reversed by NaCl 0.5 M. Furthermore, addition of β₂-GPI to aPL IgG significantly increased the amount of aPL binding to an ATP column. We conclude that aPL IgG bind ATP, probably through β₂-GPI. This binding could interfere with the normal extracellular function of ATP and similar neurotransmitters.

Antibodies of IgM subclass to phosphorylcholine and oxidized LDL are protective factors for atherosclerosis in patients with hypertension

OBJECTIVE

To determine the importance of antibodies against phosphorylcholine (PC) and oxidized low density lipoprotein (OxLDL) for development of atherosclerosis.

METHODS AND RESULTS

Two hundred and twenty six individuals with established hypertension (diastolic pressure > 95mmHg) were from European Lacidipine Study on Atherosclerosis. Antibodies of IgG and IgM subclass were tested by ELISA against PC (aPC), cupper-oxidized (ox)- or malondialdehyde (MDA)-modified LDL. High-sensitivity C-reactive protein was measured by nephelometry. As a surrogate measure of atherosclerosis, we used the mean of the maximum intima-media thicknesses (IMT) in the far walls of common carotids and bifurcations was determined by ultrasonography at the time of enrolment, and 4 years following enrolment. aPC could be competed out by PC and OxLDL, while cardiolipin (CL) and beta2-glycoprotein I (beta2GPI) were less effective and phosphatidylserine (PS) not at all. Increases in IMT at follow-up were less common in subjects which at the time of enrolment had high IgM aPC (both 75th and 90th; odds ratios: 0.46; CI: 0.25-0.85; 0.36; CI: 0.15-0.87) and high IgM aOxLDL and aMDA-LDL (90th; odds ratios 0.27; p = 0.01; CI: 0.11-0.69 and 0.27; p = 0.01; CI: 0.11-0.69). CRP was unrelated to IMT-changes. The relationship between IgM aPC, aOxLDL and aMDA-LDL and changes in IMT was independent of age, treatment with atenolol or lacidipine, smoking and lipids. Women had higher levels of IgM antibodies tested (p < 0.05).

CONCLUSIONS

High levels of IgM-antibodies against PC and OxLDL predict a favourable outcome in the development of carotid atherosclerosis in hypertensive subjects. Whether these antibodies could be used therapeutically deserves further study.

Antibodies against oxidized LDL and cardiolipin and mortality in patients with coronary heart disease

The association between antibodies against oxidized LDL (oxLDL) and cardiolipin and the risks of death and cardiovascular disease events were evaluated in patients with established coronary heart disease (CHD). The patients (mean age: 61 years, range: 33-74 years) were participants in the EUROASPIRE study; 108 of them had undergone coronary artery bypass surgery, 106 had balloon angioplasty, 101 had a diagnosis of acute myocardial infarction (AMI), and 98 acute myocardial ischemia. Antibodies against oxLDL and cardiolipin were measured and incidence of CHD events and deaths were followed up for 5 years in 284 men and 129 women. During the follow-up 36 patients died and 21 had AMI. After adjustment for cardiovascular disease risk factors the relative risks (RR [95% confidence interval]) of death were 1 (reference), 2.50 (0.97-6.49) and 2.21 (0.85-5.80) in increasing tertile categories of anti-oxLDL antibody titers, respectively (P for trend 0.16). The risks of CHD-death or AMI combined were 1 (reference), 2.61 (1.02-6.65) and 1.06 (0.37-3.03) in increasing tertile categories of anticardiolipin antibody titers, respectively (P for trend 0.03). In conclusion, the results suggest that antibodies against oxLDL and cardiolipin are not major predictors of risks of death and CHD events in patients with established CHD.

[Recurrent miscarriage or failed in-vitro fertilization: antibodies against annexin V, cardiolipin, beta-2-glycoprotein-1 and APC-resistance]

Antibodies against annexin-V, a potent anticoagulant abundant in placental tissues, were recently controversially reported to be associated with recurrent miscarriages or failures of in-vitro-fertilization (IVF) attempts.

PATIENTS, MATERIAL, METHODS

We screened 56 women (34.7 +/- 4.3 years of age: mean +/- 1 SD) with recurrent IVF failures and/or early pregnancy losses for resistance against activated protein C, lupus anticoagulant and antibodies against annexin V, cardiolipin or beta(2)-glycoprotein-1. Among them the prevalence of APC-R (8/56, 14%) and elevated levels of IgG- or IgM-anti-cardiolipin antibodies (7/56, 12%) were more common than elevated levels of (IgG or IgM) antibodies against beta(2)-glycoprotein-1 (3/56, 5%) or annexin-V (1/56, 2%). 42 (75%) of the women had another IVF-attempt after this haemostaseological evaluation and received low molecular weight heparin and/ or acetylsalicylic acid in the case of positivity for APC-resistance, lupus anticoagulant or antibodies against annexin V, cardiolipin or beta(2)-glycoprotein-1.

RESULTS

The outcome of these IVF-attempts were 19 pregnancies (34%): 4 early miscarriages (7%) and 15 so far uncomplicated pregnancies (27%). The only woman with an elevated anti-annexin V (IgG) level had had 7 IVF before and received 40 mg Enoxaparin (Lovenox) subcutaneously once daily during the 8(th) IVF, which resulted in a healthy pregnancy.

DISCUSSION, CONCLUSION

Our findings suggest that among women with recurrent IVF failures anti-annexin V antibody positivity is less prevalent than APC-resistance, lupus anticoagulant (LA) or elevated levels of antibodies against cardiolipin, beta(2)-glycoprotein-1 and that the IVF-result of women with APC-R, LA or with elevated levels of antibodies against annexin V, cardiolipin or beta(2)-glycoprotein might be positively influenced by low molecular weight heparin.

Proliferating brain cells are a target of neurotoxic CSF in systemic autoimmune disease

Brain atrophy, neurologic and psychiatric (NP) manifestations are common complications in the systemic autoimmune disease, lupus erythematosus (SLE). Here we show that the cerebrospinal fluid (CSF) from autoimmune MRL-lpr mice and a deceased NP-SLE patient reduce the viability of brain cells which proliferate in vitro. This detrimental effect was accompanied by periventricular neurodegeneration in the brains of autoimmune mice and profound in vivo neurotoxicity when their CSF was administered to the CNS of a rat. Multiple ionic responses with microfluorometry and protein peaks on electropherograms suggest more than one mechanism of cellular demise. Similar to the CSF from diseased MRL-lpr mice, the CSF from a deceased SLE patient with a history of psychosis, memory impairment, and seizures, reduced viability of the C17.2 neural stem cell line. Proposed mechanisms of cytotoxicity involve binding of intrathecally synthesized IgG autoantibodies to target(s) common to different mammalian species and neuronal populations. More importantly, these results indicate that the viability of proliferative neural cells can be compromised in systemic autoimmune disease. Antibody-mediated lesions of germinal layers may impair the regenerative capacity of the brain in NP-SLE and possibly, brain development and function in some forms of CNS disorders in which autoimmune phenomena have been documented.

Anti-Phospholipid Antibodies against Phosphatidylinositol, and Phosphatidylserine are More Significant in Reproductive Failure than Antibodies against Cardiolipin only

PROBLEM

The humoral immune response to phospholipids was investigated in women with reproductive failure [1073 women after one in vitro fertilization (IVF), 853 women after two and more IVF, 627 women after three and more repeated spontaneous miscarriages or missed abortions, 412 women after diagnostic laparoscopy] and compared with that of 391 healthy fertile women.

METHOD OF STUDY

Sera from all women in the study were tested by enzyme-linked immunosorbent assay (ELISA) for the detection of IgG, IgA, and IgM isotypes of antibodies against seven phospholipids (aPLs), i.e. cardiolipin, L-phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, phosphatidylethanolamine, phosphatidylacid as well as against beta2-glycoprotein I.

RESULTS

Patients after two and more IVF (48 and 50%, respectively), patients with three and more repeated spontaneous miscarriages (50 and 46.5%, respectively) are associated with significantly higher serum levels of aPLs against inositol, and L-serine (P < 0.01). A quarter of them were positive for three and more aPLs.

CONCLUSION

It seems that determination of aPLs only against cardiolipin in reproductive failure is not sufficient for obstetric-gynecology diagnosis as the primary anti-phospholipid syndrome. Our long-ranging study (from 1998 to 2003) shows the necessity to test for a complete aPLs profile. Sera from patients after two and more IVF procedures, and sera from women after three and more repeated abortions are immunologically more active than sera from women after one unsuccessful IVF and sera from women after diagnostic laparoscopy. This important result is very significant for future treatment.

Palsy of the rear limbs in Mycobacterium lepraemurium-infected mice results from bone damage and not from nerve involvement

A small but relatively constant proportion (3-5%) of mice chronically infected with Mycobacterium lepraemurium (MLM) develops bilateral paralysis of the rear limbs. The aim of the study was to investigate whether or not the bilateral leg palsy results from nerve involvement. Direct bacterial nerve infection or acute/delayed inflammation might possibly affect the nerves. Therefore, palsied animals were investigated for the presence of: (a) histopathological changes in the leg tissues including nerves, bones and annexes, and (b) serum antibodies to M. lepraemurium and M. leprae lipids, including phenolic glycolipid I from M. leprae. Histopathological study of the palsied legs revealed that the paralysis was not the result of direct involvement of the limb nerves, as neither bacilli nor inflammatory cells were observed in the nerve branches studied. Antibodies to brain lipids and cardiolipin were not detected in the serum of the palsied animals, thus ruling out an immune response to self-lipids as the basis for the paralysis. Although high levels of antibodies to MLM lipids were detected in the serum of palsied animals they were not related to limb paralysis, as the nerves of the palsied legs showed no evidence of inflammatory damage. In fact, nerves showed no evidence of damage. Paralysis resulted from severe damage of the leg bones. Within the bones the bone marrow became replaced by extended bacilli-laden granulomas that frequently eroded the bone wall, altering the normal architecture of the bone and its annexes, namely muscle, tendons and connective tissue. Although this study rules out definitively the infectious or inflammatory damage of nerves in murine leprosy, it opens a new avenue of research into the factors that participate in the involvement or the sparing of nerves in human and murine leprosy, respectively.

The Antiphospholipid Antibody Syndrome Research in Patients with Retinal Venous Occlusion

BACKGROUND

The antiphospholipid antibody syndrome (APAS) is a condition associated with abnormal thrombosis and the presence of anticardiolipin antibodies (aCL).

METHODS

Thirty-two patients (20 male and 12 female) aged between 29 and 75 years (mean +/- SD: 56.4 +/- 12.34) with retinal venous occlusive disease were studied. All patients with a history of venous occlusive disease within the previous 8 months were included in the study. Diagnoses were made by fundus examination and fundus fluorescein angiography (FFA). Anticardiolipin IgM and IgG antibodies, antinuclear antibodies (ANA), and IL-1beta were investigated in all patients.

RESULTS

Neither aCL-IgM nor aCL-IgG was observed as positive in this group. Only four patients were found to be ANA positive. However, serum levels of IL-1beta were higher than those of controls (p <0.001). Mean IL-1beta was found to be 18.06 +/- 3.39 pg/mL (mean +/- SE), respectively. IL-1beta levels were found to be significantly different from those of controls (2.7 +/- 0.68 pg/mL) (p <0.001). In this study, antiphospholipid antibody positivity was not determined in any patients.

CONCLUSIONS

As a result, IL-1beta level appears higher in retinal venous occlusive disease. This cytokine measurement might be used as a diagnostic indicator for venous occlusive disease.