Clinical relevance of multiple antibody specificity testing in anti-phospholipid syndrome and recurrent pregnancy loss

We wanted to evaluate whether testing for anti-phosholipid antibodies other than anti-cardiolipin (aCL) and anti-beta-2 glycoprotein I (abeta2GPI) immunoglobulin (Ig)G and IgM identifies patients with recurrent pregnancy loss (RPL) who may be positive for anti-phospholipid syndrome (APS). In a cross-sectional study comprising 62 patients with APS, 66 women with RPL, 50 healthy blood donors and 24 women with a history of successful pregnancies, we tested IgM and IgG antibodies to phosphatidic acid, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl glycerol, phosphatidyl inositol and phosphatidyl serine with and without beta-2 glycoprotein I (beta2GPI) from a single manufacturer as well as aCL and abeta2GPI antibodies. Diagnostic accuracies of individual and combined anti-phospholipid (aPL) assays were assessed by computing sensitivities, specificities, positive predictive values and negative predictive values together with their 95% confidence intervals. There was a general trend for increased sensitivities in the presence of beta2GPI co-factor with significant effect for certain specificities. The overall combined sensitivity of the non-recommended aPL assays was not significantly higher than that of the aCL and aB2GPI tests. Multiple aPL specificities in RPL group is not significantly different from controls and therefore of no clinical significance.     

Specificity of anti-phospholipid antibodies in infectious mononucleosis: a role for anti-cofactor protein antibodies

The antigen specificity of anti-phospholipid antibodies in infectious mononucleosis (IM) was studied using ELISA for the detection of anti-beta2-glycoprotein I (beta2-GPI), anti-annexin V, anti-protein S and anti-prothrombin antibodies and TLC immunostaining for the detection of anti-phospholipid antibodies. This technique enabled us to look at antibodies reacting to 'pure' phospholipid antigens in the absence of protein contamination. Sera from 46 patients with IM, 18 with systemic lupus erythematosus (SLE), 21 with primary anti-phospholipid antibody syndrome (PAPS), 50 with Helicobacter pylori infection and 30 healthy blood donors were tested. This study highlights anti-phospholipid antibodies in patients with IM as specific 'pure' anti-cardiolipin antibodies, while in PAPS and SLE patients anti-phosphatidylserine and anti-phosphatidylethanolamine antibodies were also found. This investigation also shows that the anti-cardiolipin antibodies found in IM can be present with anti-cofactor protein antibodies. The higher prevalence of anti-cofactor antibodies found in IM sera than in Helicobacter pylori sera may be due to the immunostimulatory effect and/or the polyclonal activation often observed in course of Epstein-Barr virus infection. However, anti-beta2-GPI and, to a lesser extent, anti-prothrombin antibodies occur with a significantly lower prevalence in IM than in PAPS patients. This finding suggests that these antibodies should be regarded as the expression of the broad autoimmune syndrome involving the phospholipid-binding plasma proteins.     

Thin-layer chromatography immunostaining in detecting anti-phospholipid antibodies in seronegative anti-phospholipid syndrome

In clinical practice it is possible to find patients with clinical signs suggestive of anti-phospholipid syndrome (APS) who are persistently negative for the routinely used anti-phospholipid antibodies (aPL). Therefore, the term proposed for these cases was seronegative APS (SN-APS). We investigated the clinical usefulness of thin-layer chromatography (TLC) immunostaining in detecting serum aPL in patients presenting clinical features of SN-APS. Sera from 36 patients with SN-APS, 19 patients with APS, 18 patients with systemic lupus erythematosus (SLE), 20 anti-hepatitis C virus (HCV)-positive subjects and 32 healthy controls were examined for aPL using TLC immunostaining. Anti-β(2) -glycoprotein-I, anti-annexin II, anti-annexin V and anti-prothrombin antibodies were tested by enzyme-linked immunosorbent assays (ELISA). Eahy926, a human-derived endothelial cell line, was incubated with immunoglobulin (Ig)G fraction from SN-APS patients and analysis of phospho-interleukin (IL)-1 receptor-associated kinase (IRAK) and phospho-nuclear factor (NF)-κB was performed by Western blot, vascular cell adhesion molecule 1 (VCAM-1) expression by cytofluorimetric analysis and supernatants tissue factor (TF) levels by ELISA. TLC immunostaining showed aPL in 58·3% of SN-APS patients: anti-cardiolipin in 47·2%, anti-lyso(bis)phosphatidic acid in 41·7% and anti-phosphatidylethanolamine in 30·5%. Six of 36 patients showed anti-annexin II. Incubation of Eahy926 cells with IgG from SN-APS induced IRAK phosphorylation, NF-κB activation, VCAM-1 surface expression and TF cell release. TLC immunostaining could identify the presence of aPL in patients with SN-APS. Moreover, the results suggest the proinflammatory and procoagulant effects in vitro of these antibodies.     

Donor human leukocyte antigen specific antibodies predict development and define prognosis in transplant glomerulopathy

The pathogenesis of transplant glomerulopathy (TG) remains unclear, with evidence of human leukocyte antigen (HLA) antibodies as important contributors to the disease. We studied the risk factors and the associations of HLA antibodies in the development of TG. Sixty-one cases with morphologic features of TG were identified and compared with contemporaneous matched patients (without TG) from a 17-year period, all undergoing renal biopsy in a single center. Univariate risk factors for TG were previous glomerulitis [odds ratio (OR) 3.3, 95% confidence interval (95% CI) [1.2-9.4], p = 0.025), delayed graft function (OR 2.3 [1.0-5.1], p = 0.042), HLA class I presensitization defined by Luminex solid-phase immunoassays (OR 5.0 [2.3-11.0]. p < 0.001), and de novo posttransplant development of donor HLA specific antibody (DSA) (OR 4.7 [1.7-13.2], p = 0.002). Only DSA remained significantly associated with TG after adjustment (OR 3.8 [1.1-12.9], p = 0.032). DSA was detected in >50% of TG patients, suggesting HLA antibodies play a critical role in TG pathogenesis. TG patients with DSA had increased risk of graft loss (median graft survival 4.4-5.2 years), whereas patients with morphologic features of TG without DSA had similar graft survival compared with the non-TG group (median graft survival 15 years). Thus, DSA is a useful predictor for graft failure in TG patients.     

The autoimmune bases of infertility and pregnancy loss

Several lines of evidence suggest that autoimmune mechanisms may influence the reproductive life and fertility of both sexes, commonly manifesting as infertility or pregnancy loss. Part of the controversy that characterizes this assumption derives from the overlooked suspect of autoimmune conditions in the absence of symptoms or the limited physician awareness in a gynecological setting. Numerous autoimmune diseases, including but not limited to systemic lupus erythematosus and anti-phospholipid syndrome, may be associated with infertility and pregnancy loss through different putative mechanisms. First, serum autoantibodies such as anti-phospholipid, anti-thyroid, or antinuclear antibodies may be directly associated with infertility, regardless of the presence of a clinically overt autoimmune disease. Second, autoimmunity may affect all stages of fertility, via ovarian failure, testicular failure, implantation failure, and pregnancy loss. Third, infertility may also be secondary to vasculitis associated with other conditions such as systemic lupus erythematosus and diabetes mellitus. This review article will illustrate and critically discuss the available data on the link between the breakdown of tolerance that characterizes autoimmune diseases and the changes in reproductive life that affect patients in real clinical setting and that often constitute the iatrotropic stimulus.     

Autoantibodies to plasminogen and tissue plasminogen activator in women with recurrent pregnancy loss

Reduced fibrinolytic activity has been described in primary anti-phospholipid syndrome (PAPS), and may be responsible for thrombotic events. Antibodies to tissue type plasminogen activator (t-PA) or plasminogen (PLG) might contribute to the hypofibrinolytic state in autoimmune diseases, but the clinical significance of these antibodies is still unclear in recurrent pregnancy loss (RPL). The aim of this study is to evaluate the prevalence and clinical significance of anti-PLG and anti-t-PA antibodies in 87 patients with a history of RPL: 54 women with well-defined PAPS (mean age 32.5 years; range 26-38) and 33 women with unexplained RPL (mean age 30 years; range 24-39). IgG anti-PLG antibodies were found in 20 and four patients from the group with RPL/PAPS and unexplained RPL, respectively; IgG anti-t-PA antibodies were found in 11 and two patients from the above two groups, respectively. IgG anti-PLG antibodies were associated with the high risk of RPL (OR 7.2, P = 0.004), especially with RPL/PAPS (OR 11.2, P < 0.001) evaluated by Fisher's exact test, while IgG anti-t-PA were associated with RPL/PAPS (OR 10.0, P = 0.01) but not with RPL (OR 6.8, P = 0.06). A significant inhibition of exogenous fibrinolysis was observed by IgG fractions from patients with anti-PLG or anti-t-PA antibodies on microplates and on the human umbilical vein endothelial cells, compared with those from healthy controls. The prevalence of IgG anti-PLG antibodies was high in RPL patients, especially in RPL/PAPS, while the prevalence of IgG anti-t-PA antibodies was high in RPL/PAPS but not in RPL, and some of them might inhibit fibrinolysis in patients.     

Does the anti-prothrombin antibodies measurement provide additional information in patients with thrombosis?

The aim of this study is to get new insight into the relevance of IgG anti-prothrombin antibodies in patients with thrombosis and to determine whether human prothrombin alone (aPT) or complexed to phosphatidylserine (aPS/PT) should be preferentially used for measuring these antibodies by enzyme-linked immunosorbent assay (ELISA). To this end, prevalence of anti-prothrombin antibodies, their characteristics in terms of avidity and heterogeneity, and their relationship with anti-beta2 glycoprotein I antibodies (abeta2GPI) were studied in 152 patients with thrombosis. Patients were divided into two groups according to the presence or absence of antiphospholipid antibodies (aPL), called aPL+ or aPL-, respectively. In the aPL- group (n=90), the prevalence of anti-prothrombin antibodies was substantial (10%) but not significantly different from that of control (5%). In the aPL+ group (n=62), lupus anticoagulant (LA) or anticardiolipin antibodies (aCL) positive, 61% were positive for anti-prothrombin antibodies with no statistical difference between aPT and aPS/PT prevalence (42% vs. 55%, respectively). In the whole thrombotic population, 19% were only aPT and 34% only aPS/PT suggesting the presence of different antibodies. Absorption experiments confirmed the heterogeneity of aPT and aPS/PT. No difference in their avidity was demonstrated. From the aPL+ group, 60 were LA positive. Among them, 18% were negative for abeta2GPI and anti-prothrombin antibodies showing that the detection of these antibodies could not substitute for LA determination. In conclusion, our data show that the screening of the different anti-prothrombin antibodies is not warranted in the aPL+ group since these antibodies do not provide additional information compared to aCL, LA and/or abeta2GPI measurement. Nevertheless, the substantial prevalence of anti-prothrombin antibodies in the aPL- group should be further explored in a large prospective study.     

Endometriosis-associated infertility: double intrauterine insemination improves fecundity in patients positive for antiendometrial antibodies

Citation
Subit M, Gantt P, Broce M, Seybold DJ, Randall G. Endometriosis‐associated infertility: double intrauterine insemination improves fecundity in patients positive for antiendometrial antibodies. Am J Reprod Immunol 2011; 66: 100–107 Problem Prospective registry study evaluating effects of endometriosis (E) and serum antiendometrial antibodies (AEA) on fecundity in intrauterine insemination (IUI) cycles. Method of study AEA assays on 572 consecutive women receiving 969 single and 274 double IUI cycles. Logistic regression was utilized. Results Fecundity was 11.5% (143/1243 cycles). Double IUI improved fecundity with significance achieved in certain study groups. Compared to the AEA? subgroup, all study groups except for the E+ AEA? group had significantly lower fecundity. Two study groups receiving double IUI had significantly increased fecundity, E? AEA+ (OR: 5.1, CI: 1.1–22.7, P = 0.032) and E+ AEA+ (OR: 4.1, CI: 1.2–14.0, P = 0.025) and significant predictors of pregnancy (E? AEA+, OR: 7.8, CI: 1.7–36.2, P = 0.009 and E+ AEA+, OR: 4.2, CI: 1.2–15.1, P = 0.026). Conclusion Double IUI improves fecundity in AEA+ patients. E‐associated infertility is better diagnosed by the AEA assay than by surgery. Double IUI should be attempted prior to assisted reproductive technologies in AEA+ patients with normal fallopian tubes.     

Pregnancy: Antiphospholipid antibodies and human reproductive failure

Routine screening for circulating antiphospholipid antibodies(aPL), namely the lupus anticoagulant (LA) and anticardiolipinantibodies (aCL), was carried out in a total of 1273 women aged<45 years. Of them, 822 were experimental subjects and 451were controls. The former comprised the following three studygroups: 498 infertile patients (group 1), 284 spontaneous recurrentaborters (group 2), and 40 patients with repeated failure ofembryo transfer (group 3). Controls included five groups ofwomen: 125 normal healthy women who had never been pregnant(group 4), 125 normal healthy parous women with no previousabortion (group 5), 52 women in labour after normal pregnanciesat term (group 6), 49 infertile patients achieving a livebirthwith their first in-vitro fertilization (IVF) and embryo transfer(group 7), and 100 female patients with systemic lupus erythematosus(positive controls, group 8). aPL positivity in the eight groupsstudied was as follows: 2.4, 9.2, 10, 0.8, 0, 0, 0 and 42% respectivelyfor groups 1 to 8. There were no differences within groups 1and 3 regarding incidence of aPL when patients were groupedaccording to infertility aetiological factors and indicationsfor IVF respectively. Twenty-six out of 284 recurrent aborters(9.2%) tested positive for aPL, and the LA and/or aCL were identifiedas the aetiological factor in 12% of patients (24/199) withsupposedly unexplained recurrent abortion. Incidence of positivesera for aPL in group 1 was similar to that observed in controlgroups 4, 5 and 6. On the contrary, incidence of aPL positivityin groups 2 and 3 was significantly higher than in control groups4, 5 and 6 and among infertile women (group 1). The differencebetween groups 3 and 7 almost reached statistical significance.Interestingly, there was no difference between groups 2 and3, but groups 2 and 7 resulted probably different regardingincidence of aPL positive sera. As expected, the highest incidenceof patients testing positive for aPL was found in group 8. Seveninfertile patients having circulating aPL and becoming pregnantspontaneously or after specific infertility treatment, successfullycarried to term in spite of the fact that they did not receiveimmunotherapy. Among recurrent aborters, the live-born babyrate was significantly higher after treatment with low-doseaspirin than prior therapy. It is concluded that the presenceof circulating aPL may be associated with recurrent abortionbut not with infertility. In addition, our results favour apossible role of aPL hi failure of implantation after IVF andembryo transfer.     

Recurrent reproductive wastage and immunologic factors

PROBLEM: The causes of recurrent reproductive wastage are varied and complex. The present study was designed to focus on the role of immunologic factors in cases where other causes were not evident. METHOD OF STUDY: Over 20 years, more than 1500 couples were evaluated in our clinic because of recurrent spontaneous abortion. Women were tested for anti-phospholipid antibodies and plasma contact proteins of the intrinsic pathway of blood coagulation after endocrine, organic, infectious and genetic etiologies of miscarriages were excluded. RESULTS: Anti-phosphatidylethanolamine antibodies, anti-annexin antibodies, and factor XII deficiency were more common factors in recurrent spontaneous abortion patients than were anti-cardiolipin antibodies in terms of induction of recurrent pregnancy losses. Paternal leukocyte immunotherapy of patients without such abnormalities was associated with a significantly improved success rate. CONCLUSIONS: Recurrent reproductive wastage can be minimized by individualized therapy based on comprehensive evaluation of immunologic factors, including several anti-phospholipid antibodies.     

Autoantibody panel screening in recurrent miscarriages

PROBLEM: Antiphospholipid autoantibodies (aPL), antithyroid antibodies and anti-extractable nuclear antigens (anti-ENA) have all been reported to be associated with recurrent miscarriages (RM) and infertility. However, this association remained controversial. MATERIALS AND METHODS: Fifty-eight women with impaired fertility (38 women with RM and 20 women with infertility, but no miscarriages) and 28 control parous women were screened for seven autoantibodies [antithyroglobulin (aTG), antithyroid peroxidase (aTPO), anticardiolipin (aCL), antiphosphatidyl-serine (aPS), antiprothrombin antibodies (aPT), anti-beta 2 glycoprotein 1 (abeta2GP1), and anti-ENA]. There was no evidence for autoimmune diseases in the patients or the control. The analysis was also performed with several panels of autoantibodies, each of which contained two or more autoantibodies. RESULTS: Anti-TPO was the only antibody to be associated with RM (P = 0.01). A significant association was found between RM, and autoantibodies in the 'aTG + aTPO + anti-ENA' or 'aTG + aTPO' panels. The 'aTG + aTPO + anti-ENA' panel was also associated with RM when the analysis was performed only on 17 women who had secondary infertility: 10 from the 38 women with RM, and seven from the 20 women with infertility and no miscarriages. A significant association (P < 0.001) was also apparent between anti-CL and anti-PS and infertility compared with the 28 control women. CONCLUSIONS: RM was associated with autoantibodies to aTPO and the combined panel of aTPO, aTG and anti-ENA, but not with aPL. aPL were associated with infertility.     

Antinuclear autoantibodies, complement level, hypergammaglobulinemia and spontaneous intrauterine hematoma in pregnant women

PROBLEM: To examine the associative relationship among autoantibodies, C4 levels and intrauterine hematomas (IUH) in more detail than in the studies published earlier. METHOD OF STUDY: We performed a retrospective study of 54 women with poor obstetric outcomes. Sera were screened for antinuclear antibodies (ANA), anti-DNA antibodies, antiphospholipid antibodies (aPL), and antithyroid antibodies. C4-complement and gammaglobulin levels were also monitored. We compared the main variables in IUH complicated pregnancy group with the risk pregnancy group without IUH. We also compared these variables in the IUH cases before and during IUH. RESULTS: Eight IUH were detected. The average number of spontaneous losses for these eight women was 3.3 +/- 2.1 (range: 1-8). aPL was present in 100% of cases. ANAs and hypergammaglobulinemia were present in 50% of cases and low C4 in 87.5% of cases. After comparing these variables apart from C4 before and during IUH, we found no statistical differences. However, C4 was low in four patients before IUH and in seven patients during IUH (OR: 7.0; 95% CI: 0.57-86.33). When we compared autoantibodies apart from lupus anticoagulant (LAC) between the two groups, no differences were observed. However, seven of the eight (87.5%) patients with IUH were LAC positive whereas only 24 of the 46 patients (52.1%) were positive in the non-IUH group (OR: 6.42; 95% CI: 0.73-56.41). Rapid plasma reagin was present in 8/46 in the non-IUH group (16.7%) and 5/8 in the IUH group (62.5%) P < 0.015). CONCLUSIONS: In women with poor obstetric histories, autoantibodies, especially antiphospholid antibodies, may play a role in the IUH development especially if low C4 and/or hypergammaglobulinemia are present.     

育龄妇女不育不孕的实验室诊断及实验结果分析

目的探讨育龄妇女自身免疫抗体及生殖道衣原体(CT)、支原体(UU)感染与不育不孕患者的关系。方法选择2007年来我院门诊就诊和妇科住院的自然流产患者、不孕患者,没有反复流产史,且有一个健康婴儿的健康体检者,分别检测封闭抗体(APLA)、抗精子抗体(AsAb)、抗子宫内膜抗体(EMAb)、抗心磷脂抗体(ACA)解脲支原体(UU)和沙眼衣原体(CT)。结果自然流产患者中APLA阴性占75%,不孕患者APLA阴性占17.73%,对照组APLA阴性占8.14%;流产组、不孕组的APLA、AsAb、EMAb、ACA、UU、CT阳性检出率明显高于对照组。结论育龄妇女体内存在APLA、AsAb、ACA、EMAb及生殖道支原体或衣原体感染与不育不孕患者密切相关,对有不良孕产史及不孕的患者进行自身免疫抗体及生殖道衣原体、支原体的检测,可为诊断及治疗提供科学的依据。     

Different Antiphospholipid Antibody Specificities are Found in Association with Early Repeated Pregnancy Loss Versus Recurrent IVF-Failure Patients

PROBLEM: Patients having in vitro fertilization and embryo transfer (IVF-ET) failures show an increased incidence of antiphospholipid (aPL) antibodies; but controversy exists whether aPL can induce IVF-failure. This study was designed to compare aPL specificities between recurrent IVF-failure patients versus repeated early pregnancy loss (RPL) patients. METHOD OF STUDY: Anticardiolipin (aCL), lupus anticoagulant (LA), antiphosphatidylserine (aPS), antiphosphatidylethanolamine (aPE), and antinuclear antibodies (ANA) were measured in 74 recurrent IVF-ET failure patients and compared with 273 early RPL patients ( < 10 weeks). RESULTS: An increased incidence of IgG-aPE and ANA was observed for both groups in comparison with controls. Patients with recurrent IVF-ET failure showed a significantly higher prevalence of IgG-aPS (P = 0.02) and IgG-aCL (P = 0.02) when compared with early RPL patients or controls. CONCLUSIONS: IgG-aPS and IgG-aCL may be responsible for some IVF-failures. Additional studies are needed to clarify the pathogenic role of IgG-aPS and IgG-aCL on IVF-ET failure.     

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.     

Caffeine intake, CYP1A2 polymorphism and the risk of recurrent pregnancy loss

Some case-control studies have demonstrated that caffeine intake and high CYP1A2 activity increase risks of recurrent pregnancy loss (RPL) but the multifactorial effect is obscure. To investigate whether susceptible women who have more caffeine intake are at high risk of RPL, a case-control study of 58 cases with two or more RPL and fertile 147 controls was performed. The association between daily caffeine intake together with CYP1A21F (AA versus CA and CC) genotype and RPL was assessed. Without consideration of the genotype, there were no significant differences of the RPL risk in proportion to daily caffeine intake [less than 100 mg (reference); 100-299 mg: odds ratio (OR), 1.29; 95% confidence interval (CI), 0.66-2.50; 300 mg or more: OR, 1.82; 95% CI, 0.72-4.58; P for trend, 0.20]. However, the RPL risk significantly increased only among women who had homozygous CYP1A21F alleles with a dosage effect of daily caffeine intake [less than 100 mg (reference); 100-299 mg: OR, 1.94; 95% CI, 0.57-6.66; 300 mg or more: OR, 5.23; 95% CI, 1.05-25.9; P for trend, 0.03]. It was demonstrated for the first time that an increase in caffeine intake deteriorates the fecundity among susceptible women.     

Early onset of autoimmunity in MRL/++ mice following immunization with beta 2 glycoprotein I.

Antiphospholipid antibodies (aPL) are associated with thrombosis, thrombocytopenia and recurrent fetal loss in humans and in some animal models. Immunization with beta 2 glycoprotein I (beta 2GPI) induced aPL production in normal rabbits and mice. However, the association of these antibodies with disease manifestations remains controversial. To determine whether induction of aPL by beta 2GPI immunization in an autoimmune strain of mice (MRL/++) would result in acceleration of clinical and serological autoimmune disease manifestations, three groups of 8-week-old female mice were studied. One group was immunized with beta 2GPI, and one with ovalbumin (OVA); the third was not immunized. After two booster injections, sera were analysed for the presence of anticardiolipin (aCL) and anti-DNA by ELISA and anti-nuclear antibody (ANA) by immunofluorescence. Mice were studied for thrombocytopenia, proteinuria, fecundity rates, litter sizes and the development of central nervous system dysfunction. Elevated levels of aCL, anti-DNA and ANA were detected in all beta 2GPI-immunized, in three OVA-immunized, and in none of the unimmunized mice. The anti-DNA antibodies were inhibited by CL micelles, suggesting cross-reactivity between aCL and anti-DNA. Platelet counts, fecundity rates and litter size were reduced in beta 2GPI-immunized but not in OVA-immunized or unimmunized mice. None of the mice developed neurological dysfunction or significant proteinuria over a 10-week period post-immunization. These findings suggest that beta 2GPI immunization induces aPL in MRL/++ mice associated with accelerated autoimmune manifestations resembling the antiphospholipid syndrome.     

Anti-prothrombin antibodies are associated with adverse pregnancy outcome

Citation Marozio L, Curti A, Botta G, Canuto EM, Salton L, Tavella AM, Benedetto C. Anti‐prothrombin antibodies are associated with adverse pregnancy outcome. Am J Reprod Immunol 2011; 66: 404–409 Problem Women with antiphospholipid antibodies (aPL) such as lupus anticoagulant, anticardiolipin antibodies, and anti‐β₂ glycoprotein‐1 antibodies are at high risk of late pregnancy complications, such as severe pre‐eclampsia, placental insufficiency, and fetal loss. It has been observed that aPL consists of a heterogeneous group of antibodies targeting several phospholipid‐binding plasma proteins, including also anti‐prothrombin (anti‐PT), anti‐protein S (anti‐PS), and anti‐protein C (anti‐PC) antibodies. Their potential role in late pregnancy complications is not known. The aim of this work was to investigate the association between those autoantibodies and histories for adverse pregnancy outcome. Method of study Anti‐PT, anti‐PS, and anti‐PC antibodies were evaluated in 163 patients with previous severe pre‐eclampsia, fetal death, and/or placental abruption and in as many women with previous uneventful pregnancies, negative for aPL. Results The prevalence of anti‐PT antibodies was higher in cases than in controls (OR, 95% CI: 10.92, 4.52–26.38). The highest prevalence was observed in subjects with fetal death. Conclusion Anti‐PT antibodies appear to be associated with adverse pregnancy outcome, irrespectively of aPL.     

Heterogeneity of binding reactivity to different phospholipids of antibodies from patients with systemic lupus erythematosus (SLE) and with syphilis.

The binding specificities were investigated of anti-phospholipid antibodies derived from sera from 55 patients with SLE and related diseases, and from 33 patients with syphilis. Antibodies from both these groups of patients bind strongly to cardiolipin in solid-phase immunoassays, but only antiphospholipid antibodies from patients with autoimmune diseases are associated with thrombotic complications and recurrent spontaneous abortions. IgG anti-phospholipid antibodies from both groups of patients cross-reacted with a range of negatively charged phospholipids, but binding to neutral phospholipids was largely restricted to sera from patients with syphilis. A monoclonal IgM lambda anti-cardiolipin antibody, derived from a patient with autoimmunity, was used to inhibit binding of anti-phospholipid antibodies to cardiolipin and to phosphatidic acid. This antibody inhibited the binding of autoimmune sera to cardiolipin more strongly than sera from syphilis patients, but the converse pattern of inhibition of binding to phosphatidic acid was observed. The VDRL titre correlated with anti-phospholipid antibody activity in sera from syphilis patients, but not from those with autoimmunity. Lupus anti-coagulant activity correlated weakly with IgG antibody levels to each of the negatively charged phospholipids among the patients with autoimmunity. Lupus anticoagulant activity did not correlate uniquely with any anti-phospholipid antibody specificity. These results provide further documentation of the great heterogeneity of anti-phospholipid antibodies associated with autoimmune disease and syphilis.