Biomedical subjects

Miri Blank

Publications and source records attributed to Miri Blank.

At least 19 recordsLinked to original sources

PubMed2006

Identification of a peptide mimicking the binding pattern of an antiphospholipid antibody.

Our objective was to characterize monoclonal antiphospholipid antibodies (APL) and identify disease-associated antigens in patients with the antiphospholipid syndrome (APS). We used the monoclonal antibody HL-5B, derived from a patient with APS suffering from multiple ischemic events, to screen a 12-mer peptide phage display library (New England Biolabs, London, England). The identified phage clones were sequenced and the derived consensus peptide was synthesized. The peptide was used to perform competitive inhibition experiments for their ability to inhibit the binding of the monoclonal antibody and of serum antibodies to cardiolipin and phosphatidylserine. Additionally patients and control sera were screened for their binding reactivities to this peptide. Using this 12-mer phage display library the peptide APHKHKASLSIY as consensus peptide for the monoclonal antiphospholipid antibody HL-5B could be identified. In competitive inhibition studies we showed that this peptide is able to inhibit the binding of HL-5B to cardiolipin and phosphatidylserine and furthermore another antiphospholipid antibody used as control was also inhibited in its binding to phospholipids. Using 21 sera from APS patients 67% showed a binding to the peptide in a specific ELISA above the cutoff level, generated with sera from 20 healthy controls. Out of the reactive patients' sera we used two exemplarily to perform inhibition studies. Both sera could be inhibited more than 40% in their binding to cardiolipin in a commercially available antiphospholipid antibody assay (Aescu.diagnostics, Wendelsheim, Germany). The identified peptide APHKHKASLSIY simulates the antigenic structure recognized from a subpopulation of serum antiphospholipid antibodies. This might indicate that the diversity of the antiphospholipid antibodies is limited and only few epitopes or few common structures are responsible for the development of those antibodies. Tests using these epitopes will strongly improve laboratory diagnosis of the APS.

Adult↗

PubMed2006

Genetic and immunological factors interact in a mouse model of CNS antiphospholipid syndrome.

The antiphospholipid syndrome (APS) includes systemic and central nervous system (CNS) pathology associated with antibodies to a complex of phospholipids and beta(2)-glycoprotein I (beta(2)-GPI). We have recently reported the induction of APS associated with behavioral and cognitive deficits in BALB/c female mice that developed 4-5 months after immunization with beta(2)-GPI. In the present study, we examined the influence of genetic factors on the ability to induce experimental APS with CNS involvement by testing several mouse strains immunized with beta(2)-GPI. Female mice from five strains were immunized once with beta(2)-GPI in complete Freund's adjuvant (CFA) or with CFA alone (controls). Autoantibody levels were examined at 1 and 5 months after immunization. Neurological assessment in a staircase test was performed 4-5 months following the immunization. Induction of APS resulted in elevated levels of antibodies against negatively charged phospholipids and beta(2)-GPI in all five mouse strains. Autoantibody levels were significantly higher in Balb/c, ICR, and C57BL/6 mouse strains compared to AKR and C3H. aPL levels dropped significantly more in the C57BL/6 compared to Balb/c mice over a period of 4 months. Hyperactivity reflected by higher number of stairs climbed in 3 min, was induced by APS in the Balb/c and ICR, mouse strains. Exploratory behavior reflected by more frequent rears, was seen in the APS-Balb/c and AKR mice. Hypoactivity and less exploration were seen in the APS-C57BL/6 and C3H mice. The study supports a link between high levels of aPL and behavioral changes in a mouse APS model. Qualitative differences in behavioral patterns may be due to nervous system as well as immune genetic factors. The minimal effect of APS in C57BL/6 mice may provide a suitable background for the study of transgenes in these mice.

Analysis of Variance↗

PubMed2006

Immunomodulation of experimental pulmonary fibrosis by intravenous immunoglobulin (IVIG).

OBJECTIVES: To assess the immunomodulatory effect of intravenous immunoglobulin (IVIG) using an experimental model of bleomycin-induced pulmonary fibrosis. METHODS: Pulmonary fibrosis was induced in C57BL/6 mice by direct intratracheal injection of bleomycin. Mice were treated with IVIG 1 week prior to (prevention protocol), or 10 days following bleomycin injection, when the disease was in progress. The controls used in the study included mice given phosphate buffered saline (PBS) and mice subjected to a commercial individual-IgG. Collagen-I deposits in the affected lungs were detected by Sirius red staining of paraffin embedded lung sections. The collagen-I content was measured by employing the hydroxyproline assay. RESULTS: Prevention of bleomycin-induced pulmonary fibrosis by IVIG has been demonstrated by reduced expression of collagen-I protein in the affected lungs. The hydroxyproline levels in the lungs of the IVIG-treated mice were 214.33 +/- 13.56 microg/1 g tissue, compared to the higher levels in lungs of IgG treated mice (342.44 +/- 35.60 microg/1 g tissue) or untreated controls 328.00 +/- 45.55 microg/1 g tissue, (p < 0.0001). Effective treatment of bleomycin-induced pulmonary fibrosis by IVIG has been demonstrated by the reduced expression of collagen-I protein in the affected lungs, detected by sirius red histological staining. The hydroxyproline levels in the lungs of the IVIG-treated mice were 261.00 +/- 18.81 microg/1 g tissue, in comparison to the higher levels in the lungs of the IgG treated mice (342.43 +/- 32.89 microg/1 g tissue) and of untreated controls (344.33 +/- 49.85 microg/1 g tissue), (p < 0.001). CONCLUSIONS: Based on these preliminary studies, we conclude that IVIG may have a beneficial effect in the down regulation of collagen-I levels in the lungs of mice with bleomycin-induced pulmonary fibrosis.

Animals↗

PubMed2005

The infectious etiology of the antiphospholipid syndrome: links between infection and autoimmunity.

Like many other autoimmune diseases, the antiphospholipid syndrome (APS) is considered as of a multifactorial etiology, mainly genetic susceptibility coinciding with environmental triggers, of which infectious agents are considered most prominent. Different clinical and experimental studies of the beta2 glycoprotein I (beta 2 GPI) molecule, one of the target autoantigens in APS, have linked infection to the development of APS. Using a peptide phage library, it has been shown that target epitopes of beta 2 GPI share similarities with common infectious pathogens. Also, circulating anti-beta 2 GPI antibodies have been identified in the sera of patients with different infectious conditions, and have been associated with various clinical APS manifestations. Molecular mimicry as a key mechanism linking infection and APS has been demonstrated in experimental models. In these studies, APS was induced by immunization of mice to various microbial pathogens. Anti-beta 2 GPI titers were found to be especially high following immunization with Haemophilus influenzae, Neisseria gonorrheae or tetanus toxoid. These findings contribute greatly to the understanding of APS pathogenesis, as well as create new directions for therapy modalities, namely specific peptide toleragens and antimicrobial treatment.

Animals↗

PubMed2005

The association of thrombocytopenia with systemic manifestations in the antiphospholipid syndrome.

Thrombocytopenia is frequently found in patients with the antiphospholipid syndrome (APS), yet data concerning clinical associations of thrombocytopenia in patients with APS are still scarce. We evaluated possible associations between thrombocytopenia and various APS-related manifestations in a large group of APS patients. Three hundred and seven APS patients were retrospectively evaluated, 259 women and 48 men. Most patients had primary APS (PAPS) (n=173, 56.1%). APS was associated with systemic lupus erythematosus (SLE) in 104 patients (33.9%). All patients underwent detailed medical interview and routine physical examination. Further data were obtained from patients' medical files regarding the expression of various clinical manifestations of the disease. There were 90 patients with thrombocytopenia (29.3%), the rate was significantly higher in SLE compared to PAPS patients (41.9% vs. 23.1%, p=0.001). Similar rates of thrombocytopenia were found in male (29.2%) and female (29.3%) patients. Significant associations were found between thrombocytopenia and cardiac valves thickening and dysfunction, epilepsy, chorea, arthritis, livedo reticularis and skin ulcerations. In contrast, the rates of thrombotic episodes as well as obstetric complications were similar in patients with and without thrombocytopenia. Our data suggest the presence of thrombocytopenia may be a risk factor for cardiac, neurological, articular and cutaneous complications in APS.

Abortion, Habitual↗

PubMed2005

The homogeneous multiplexed system--a new method for autoantibody profile in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a multi-systemic autoimmune disease leading to immunological aberrations and excessive multiple autoantibody production. The aim of this study was to investigate the prevalence of multiple autoantibodies in SLE patients utilizing the multiplex system method. We analyzed the presence of elevated titers of anti-Ro, anti-La, anti-RNP, anti-Sm, anti-Jo1, anti-centromere, anti-Scl-70, anti-histone, and anti-dsDNA antibodies in 199 serum samples (113 SLE patients, 86 healthy donors). We compared the type, level and number of autoantibodies and the correlation between the autoantibody profile and disease severity utilizing the SLEDAI score. Elevated titers of at least one autoantibody were detected in 48% of 42 SLE patients. Elevated titers of anti-Ro antibodies were most commonly detected. The distribution of specific autoantibodies was: anti-Ro- 23.8%, anti-dsDNA- 19%, antihistone- 19%, anti-RNP- 14.2%, anti-La antibodies- 11.9%, anti-Sm- 7.1%, anti-Scl 70-4.7%, and anti-centromere- 2.4%. Utilizing ROC analysis, the sensitivity and specificity of anti-DNA antibodies at a cutoff value of 34 IU/ml were 87.1% and 79.4% respectively. Elevated titers of anti-Jo1 antibody were not detected. There was a correlation with the titer of anti-Ro antibodies and disease activity by the SLEDAI score. Seven patients harbored one autoantibody only, 15 patients harbored 2-3 autoantibodies, 3 patients harbored 4-5 autoantibodies, and one patient harbored 6 autoantibodies. A correlation between the number of autoantibodies per patient and disease severity was found. One patient with a multitude of autoantibodies had severe lupus and a myriad of clinical manifestations. In conclusion, the multiplex system is specific and sensitive, provides an autoantibody profile in a single test, and may be useful as a diagnostic test for SLE. Elevated anti-Ro antibodies are associated with severe disease. An autoantibody load may be indicative of more severe disease.

Antibodies, Antinuclear↗

PubMed2005

Heterogeneity of anti-beta2-glycoprotein I antibodies. A factor of variability in test results.

The aim of this study was to evaluate the heterogeneity of IgGanti-beta2-glycoprotein I antibodies (IgG-abeta2GPI) as regarding their reactivity pattern against different sources of human beta2 GPI, their avidity and their association with clinical events of antiphospholipid syndrome (APS). Three thousand six hundred and eighty-four consecutive patient sera were routinely tested for IgGabeta2 GPI over 1 year using an in-house ELISA with 2 different commercial preparations of human purified beta2GPI. Of the 340 sera found positive, all those clinically documented were included in this study; 61 were positive with only one preparation (S1) and 59 with both (S2). The results of ELISA were confirmed by Western blot. Heterogeneity was stressed by testing sera with a human recombinant protein and 3 beta2GPI-related peptides. No contribution of glycosylation in the binding to beta2GPI was found. The avidity indices for each protein were significantly higher in S1 than in S2 (p=0.0021). S2 were more associated with antiphospholipid antibodies than S1 (75% versus 21% ; p<0.0001). A similar frequency of the main clinical features of APS was found in S1 and S2 sera (69% and 71%, respectively). In conclusion, our data show a heterogeneity in the antigenic reactivity pattern of IgG- abeta2 GPI and a relationship between a binding profile and antibody avidity. This heterogeneity could represent a crucial factor of variability in test results and underlines the difficulty of getting standardisation.

Antibody Affinity↗

PubMed2005

Immunomodulatory effects of intravenous immunoglobulins as a treatment for autoimmune diseases, cancer, and recurrent pregnancy loss.

Intravenous immunoglobulin (IVIG) is a safe preparation, made of human plasma of thousands of healthy donors. The fascinating history of gamma globulin therapy begins in 1930 when Finland treated pneumococcal pneumonia patients with equine serum, which prolonged their survival from pneumonia. Since then, significant breakthroughs were achieved by Cohn, Bruton, Imbach, and others, whose clinical contribution to the world of medicine was of great importance. Originally IVIG was used to treat immunodeficiencies. Later on the use of IVIG extended to autoimmune diseases as well. The efficacy of IVIG has been established only in several autoimmune diseases; clinical reports of trials, series, and case reports indicate significant improvement in many more autoimmune diseases. IVIG have also showed antimetastatic effects in a variety of cancer cell lines, as well as in a few case reports. The efficiency of IVIG has also been observed in recurrent pregnancy loss (RPL), either as a result of an autoimmune disease or spontaneous. Several attempts were made to discover the immunomodulatory effects of IVIG, but it is still not fully understood. Clearly IVIG has multiple mechanisms of actions, which are thought to cooperate synergistically. One of the main mechanisms of actions of IVIG is its ability to neutralize pathogenic autoantibodies via anti-idiotypic antibodies within IVIG preparation. The ability of IVIG to neutralize pathogenic autoantibodies is of great importance in many autoimmune diseases, as well as in RPL. In cancer cell lines, IVIG modulates the immune system in a few ways, including the induction of IL-12 secretion, which consequently activates natural killer cells, and the induction of expression of proapoptotic genes only in cancer cells. Side effects from IVIG are rare and mostly mild and transient. More importantly adverse effects can be minimized by administration to a selective patient population in a proper way: slow infusion rate of 0.4 g/Kg body weight IVIG for 5 consecutive days, given in monthly cycles. The only downside of IVIG therapy is its high price. Therefore, clinicians should balance efficiency versus cost in deciding whether or not to treat certain conditions with IVIG.

Abortion, Habitual↗

PubMed2005

Toward molecular targeting with specific intravenous immunoglobulin preparation.

Intravenous immunoglobulin (IVIg) is used successfully for therapy of inflammatory and autoimmune diseases, especially in cases of conventional therapy resistance. Within the broad spectrum of immunoregulatory activities of IVIg in vitro and in vivo, the anti-idiotypic activity neutralizing the related idiotypes is one of the main mechanisms. Furthermore, IVIg addresses integrins associated with inflammation and immune response thrombosis, such as the RGD (Arg-Gly-Asp) motif, expressed on a large number of cell surface and matrix proteins. In addition, during the last years, anti-Fas activity of IVIg was reported. We fractionated IVIg specific preparation (sIVIg) based on the multispecificities of the IVIg compound. We have generated an IVIg fraction that will show specific activity for lupus idiotypes in vitro. In NZBxW.F1 mice, results showed 200 times more beneficial effect. Using a peptide phage display library technology, we have identified a panel of lupus-related synthetic idiotypes that are mimetics of the idiotypes presented in patients with systemic lupus erythematosus. A column composed of these synthetic lupus-related idiotypes was used to prepare a large amount lupus-specific IVIg. Using the same approach, we prepared anti-anti-beta-2-glycoprotein-I (beta2GPI) specific IVIg for antiphospholipid syndrome (APS). This APS-specific IVIg reduced the fetal loss induced by anti-beta2GPI antibodies by improving the implantation process in a mouse model. Others prepared specific preparations of IVIg to RGD or for Fas. The molecular targeting with specific IVIg may be used for therapeutical purposes, using a smaller amount of IVIg, and targeting more specifically autoimmune diseases, thrombosis, or inflammatory condition.

Animals↗

PubMed2005

Intravenous immunoglobulin and fibrosis.

Fibrosis is a pathological process that includes scar formation and overproduction of extracellular matrix by the connective tissue as a response to tissue damage. Pathologies include pathological scarring as colloid and hypertrophic scars in the skin, cirrhosis of liver and gallbladder, pulmonary and bone-marrow fibrosis, and scleroderma. The molecular process is not different from normal formation of connective tissue and extracellular matrix in the normal organs. Major profibrotic agents are type 2 CD4-positive lymphocytes, CD40 receptor and ligand interaction, and the cytokines interleukin-4, transforming growth factor-beta, and platelet-derived growth factor. The major antifibrotic agent is interferon-gamma. Fibrosis was considered an irreversible process, at least clinically, and is still usually treated by anti-inflammatory and immunosuppressive agents. No proven antifibrotic therapy has shown efficacy in ameliorating clinical fibrosis. Intravenous immunoglobulin has a very good safety profile, and was found to be an ameliorating agent for several fibrotic diseases, and hence could be a drug of choice to these patients and improve their quality of life.

Animals↗

PubMed2004

Beta-2-glycoprotein-I, infections, antiphospholipid syndrome and therapeutic considerations.

Evidence supports the association between infectious agents, antiphospholipid syndrome (APS), and the presence of antiphospholipid antibodies and anti-beta2-glycoprotein-I (beta2GPI) antibodies. Several mechanisms have been proposed to explain the role of bacteria/viruses in induction of an autoimmune condition, such as molecular mimicry between structures of a pathogen and self antigen and bystander activation or bacterial/viral superantigens. Protein databases reveal high homologies between the beta2GPI-related synthetic peptides and infectious agents. Studies employing experimental APS models proved molecular mimicry between beta2GPI-related synthetic peptides, which serve as target epitopes for anti-beta2GPI Abs, and structures within bacteria, viruses (e.g., CMV), and tetanus toxoid. Any explanation of how microbial infections might induce APS must take into account the genetic predisposition. In this paper, we discuss the association of antiphospholipid antibodies, infectious states, and molecular mimicry as a proposed mechanism for development of APS.

Animals↗

PubMed2004

A peptide that shares similarity with bacterial antigens reverses thrombogenic properties of antiphospholipid antibodies in vivo.

OBJECTIVE: The factors causing production of antiphospholipid (aPL) antibodies remain unidentified. Recently, studies have shown that aPL and anti-beta2Glycoprotein I (anti-beta2GPI) antibodies with pathogenic properties can be generated with peptides from bacterial and viral origin, that mimic regions of beta2GPI. These data suggest a molecular mimicry between bacterial/viral antigens and self-proteins. In this study we examined the ability of a synthetic peptide (named peptide A, NTLKTPRVGGC) that shares similarity with common bacterial antigens, to reverse aPL-mediated thrombosis in mice in vivo. Peptide A is also found in region I/II of beta2GPI. A scrambled form of peptide A (named scA, GTKGCPNVRLT) was used as a control. METHODS AND RESULTS: Sera from 29 patients with APS bound to peptide A but not to peptide scA by ELISA in a dose-dependent fashion. Cardiolipin (CL) liposomes inhibited the binding of IgG-APS by ELISA to peptide A by 35% and to CL by 56%. The inhibition of binding to cardiolipin and to peptide A was enhanced by addition of beta2GPI to the liposomes. CL/peptide A liposomes but not peptide A alone inhibited the binding of IgG-APS to peptide A. beta2GPI alone did not inhibit binding of IgG-APS to peptide A, to beta2GPI or to CL. For the in vivo experiments, CD1 mice in groups of 20 were injected with affinity purified aPL antibodies or with control IgG-NHS twice intraperitoneally. Seventy hours after the first injection, and 30 min before the surgical procedure (induction of experimental thrombus) mice were infused i.v. in each group with either peptide A or with peptide scA. The femoral vein of the anesthetized mice were dissected to examine the dynamics of an induced thrombus in treated and control mice. The mean aCL titer of mice injected with aPL was 60 GPL units. Mice treated with aPL and infused with peptide scA produced significantly larger thrombi when compared to mice treated with IgG-NHS and peptide scA (2466+/-462 microm2 vs 772.5+/-626.4 microm2). Treatment with peptide A significantly decreased thrombus size in mice injected with aPL antibodies (1063+/-890 microm2 compared to 2466+/-462 microm2). CONCLUSION: The data indicates that a synthetic peptide that shares similarity with common bacterial antigens and with regions of beta2GPI is capable to inhibit thrombogenic properties of aPL in mice. This may have important implications in designing new modalities of prevention and/or treatment of thrombosis in APS.

Antigens, Bacterial↗

PubMed2004

Antiphosphatidylserine antibodies affect rat yolk sacs in culture: a mechanism for fetal loss in antiphospholipid syndrome.

PROBLEM: A variety of reproductive impairments have been reported in the context of the antiphospholipid syndrome (APS). APS is associated with the presence of antibodies to negatively charged phospholipids that may affect the outcome of pregnancy. METHOD OF STUDY: Rat embryos were cultured within their yolk sacs. The effects of two antiphosphatidylserine monoclonal aPS antibodies (HL5B, RR7F) regarding their influence on growth and apoptotic events of the yolk sacs, as well as on growth and the morphology of the embryos, were studied. RESULTS: Exposure of rat embryos and their yolk sacs to aPS inhibited yolk sac growth. Moreover, increased number of apoptotic events of giant cells in the aPS-exposed ectoplacental cone was found in comparison with control IgG-exposed giant cells (P < 0.05). No significant damage was observed in the embryos. CONCLUSIONS: The results suggest that aPS affect growth and apoptosis of rat ectoplacental cone.

Animals↗

PubMed2004

Features associated with epilepsy in the antiphospholipid syndrome.

OBJECTIVE: To assess the frequency of epilepsy in primary and secondary antiphospholipid syndrome (APS); to analyze the clinical and laboratory features characterizing those with epilepsy in a cohort of 538 patients with APS; and to find associated features that would suggest risk factors for epilepsy in APS. METHODS: We analyzed the clinical features of patients with APS who had epilepsy and compared them to the clinical features of non-epileptic APS patients. RESULTS: Of 538 APS patients, 46 (8.6%) had epilepsy. Epilepsy was more prevalent among APS secondary to systemic lupus erythematosus (SLE) compared to primary APS (13.7% vs 6%; p < 0.05). The patients with epilepsy had a higher prevalence of central nervous system (CNS) manifestations including focal ischemic events (strokes or transient ischemic events, 54.3% vs 24.6%; p < 0.0001) and amaurosis fugax (15.2% vs 4.9%; p < 0.05). APS patients with epilepsy had a higher frequency of valvular pathology (30.4% vs 14.6%; p < 0.01), thrombocytopenia (43.5% vs 25%; p < 0.05), and livedo reticularis (26.1% vs 11.5%; p < 0.01). The multivariate logistic regression analysis found CNS thromboembolic events as the most significant factor associated with epilepsy, with an odds ratio (OR) of 4.05 (95% confidence interval, CI: 2.05-8), followed by SLE (OR 1.4, 95% CI 1.2-4.7), and valvular vegetations (OR 2.87, 95% CI 1-8.27). CONCLUSION: Epilepsy is common in APS and most of the risk seems to be linked to vascular disease as manifested by extensive CNS involvement, valvulopathy, and livedo reticularis and to the presence of SLE. These factors, however, explain only part of the increased occurrence of epilepsy in APS and other causes such as direct immune interaction in the brain should be investigated.

Adult↗

PubMed2003

Multiple autoantibodies associated with autoimmune reproductive failure.

PURPOSE: Autoimmune factors are involved in some of the cases of reproductive failure. The aim of this paper is to discuss the association between autoantibodies and reproductive failure. METHODS: Literature review of autoantibodies associated with reproductive failure. RESULTS: Several autoantibodies were found in association with such clinical manifestations, mainly in patients having systemic lupus erythematosus or the antiphospholipid syndrome. These autoantibodies include "classical" antiphospholipid antibodies such as anticardiolipin, anti-beta2-glycoprotein-I, antiphosphatidylserine, and antiphosphatidylethanolamine. There are also some "nonclassical" antiphospholipid antibodies directed to prothrombin, thromboplastin, or mitochondrial antibodies of M5 type, which were also found in patients with reproductive failure. Moreover, animal models as well as some human studies support a role for other autoantibodies in these clinical manifestations including antihyroglobulin, antilaminin-1, anti-corpus luteum, antiprolactin, anti-poly(ADP-ribose), and lymphocytotoxic antibodies. CONCLUSIONS: Even though there is not enough data currently to support a firm association between some of these autoantibodies and reproductive failure, future studies are likely to help us determine and expand the number of autoantibodies screened in these patients.

Abortion, Habitual↗

PubMed2003

Immunization of naïve mice with mouse laminin-1 affected pregnancy outcome in a mouse model.

PROBLEM: Laminins have important roles during placental and embryonic development. The aim of our study was to determine if active immunization of mice with laminin-1 could elicit an autoimmune response, and induce features of reproductive failure. METHOD OF STUDY: BALB/c mice were immunized with mouse laminin-1. Autoantibodies to laminin-1 were measured by enzyme-linked immunosorbent assay. Pregnant mice were killed on day 14 of pregnancy and examined for pregnancy outcome. RESULTS: Mice immunized with laminin-1 developed elevated levels of anti-laminin-1 auto-antibodies contrary to the control group. A higher fetal resorption rate was found in the laminin-1 immunized group (23.8%) compared with that of the control group (12.2%), and was even higher in the subgroup of those animals with very high levels of anti-laminin-1 (P < 0.01). Laminin-1 immunized mice also had lower fetal and placental weights. CONCLUSIONS: Active immunization with laminin-1 followed by elevated circulating anti-laminin-1 antibodies results in reproductive failure manifested by a higher fetal resorption rate.

Animals↗

PubMed2003

Inhibition of ras by farnesylthiosalicylate significantly reduces the levels of autoantibodies in two animal models of the antiphospholipid syndrome.

BACKGROUND: Stimulation and proliferation of lymphocytes require activation of Ras. S-farnesylthiosalicylic acid (FTS) is a synthetic substance that detaches Ras from the inner cell membrane and induces its rapid degradation. Antiphospholipid antibodies (aPL) are a heterogeneous group of antibodies detected in patients with antiphospholipid syndrome (APS), which is associated with thrombosis, pregnancy losses, and thrombocytopenia. OBJECTIVE: To examine the effect of FTS treatment on aPL levels in a genetic autoimmune model (the MRL/lpr mice) and in an induced model of APS. METHODS: Female Balb/C mice immunized once with beta2-glycoprotein I (beta2-GPI) in complete Freund's adjuvant (CFA) and female MRL/lpr mice were treated intraperitoneally with either FTS (5 mg/Kg/day) or saline 3-5 times a week. aPL and anti-beta2-GPI antibodies were measured by ELISA. RESULTS: FTS treatment 3 times a week resulted in significant decreases of aPL and anti-beta2-GPI antibodies in both animal models. In contrast, more frequent treatment (5 times a week) had no significant effect on autantibody levels in both animal models. We further compared 2 protocols in the induced APS model, one for alternate day treatment and the other for daily treatment on the first 3 days each week, and found a decrease in autoantibody levels only in the alternate day protocol. CONCLUSIONS: Inhibition of Ras activation by FTS is effective in decreasing autoantibody levels in models of APS. The differential modulation of immune function by alternate day compared to daily treatment may provide better understanding of the role of Ras activation in this system.

Animals↗

PubMed2003

The pathogenic role of anti-thyroglobulin antibody on pregnancy: evidence from an active immunization model in mice.

BACKGROUND: The presence of antibodies to thyroglobulin (Tg) is associated with fetal loss even in the absence of thyroid dysfunction. The aim of this study was to examine whether active immunization with Tg could elicit anti-Tg autoantibodies and reproductive failure without interfering with thyroid function. METHODS: BALB/c mice that were immunized with human Tg in complete Freund's adjuvant (CFA) or injected with only CFA were studied for the development of antibodies to Tg, T4, dsDNA, ssDNA and cardiolipin. Total T4, free T4 and thyroid-stimulating hormone (TSH) levels were also assessed before and during pregnancy. Percentages of resorbed fetuses (the equivalent to human missed abortion) were compared and autoantibody presence on the placentae and fetuses was examined. RESULTS: Following immunization, high levels of anti-Tg were observed in mice immunized with Tg, compared with mice injected with CFA [0.83 +/- 0.23 versus 0.012 +/- 0.016 respectively; mean +/- SD optical density (OD) at 405 nm; P < 0.001]. The specificity of binding to Tg was confirmed by competition assay. Although total T4 levels were increased in comparison with control mice, this was associated with the presence of antibodies to T4. Indeed, free T4 levels and TSH were similar to control mice. Mice were killed after 14 days of pregnancy. The thyroid function and the histology of the thyroid glands were normal. Increased fetal wastage was found among the Tg-immunized mice compared with the CFA-injected mice (P = 0.04), with lower fetal and placental weights (fetal weights: 194 +/- 4 mg versus 240 +/- 6 mg; placental weights: 105 +/- 2 mg versus 130 +/- 3; P < 0.001 for both). Antibodies to Tg were demonstrated only on the placentae of Tg-immunized mice. CONCLUSION: Immunization with Tg results in the production of Tg antibodies and fetal resorption. These effects occur in the absence of thyroid dysfunction.

Animals↗