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Biomedical subjects

A Tincani

Publications and source records attributed to A Tincani.

At least 91 records · Page 5Linked to original sources
PubMed1995

Placental thrombosis and fetal loss after passive transfer of mouse lupus monoclonal or human polyclonal anti-cardiolipin antibodies in pregnant naive BALB/c mice.

In the present study we evaluated the effect of passive transfer of a mouse monoclonal (CAM) or a human polyclonal anti-cardiolipin IgG on pregnancy outcome in BALB/c mice. The mice were immunized through the tail vein immediately after mating with 10 micrograms of monoclonal or polyclonal anti-cardiolipin antibodies. Two other groups of mice were given a mouse irrelevant monoclonal antibody or normal human polyclonal IgG respectively, at the same dose. In mice immunized with monoclonal or polyclonal anti-cardiolipin antibody we observed a significant increase in the number of fetal resorptions and a significant reduction of the mean weights of the embryos and the placentas. In mice immunized with CAM we also found a significant decrease in the number of healthy pups, while mice infused with human aCL antibody expressed a significant reduction in the fecundity rate. The histological examination showed widespread thrombosis and necrosis in the placentas derived from the mice immunized with the anti-cardiolipin antibodies. The model supports a possible direct pathogenetic effect of anti-phospholipid antibodies in recurrent fetal loss and points out that thrombotic events at placental level can be instrumental in the pathogenesis of the obstetric complications.

Animals↗
PubMed1995

Anti-beta 2-glycoprotein I antibodies: a marker of antiphospholipid syndrome?

Anticardiolipin (aCL) and anti-beta 2-glycoprotein I(anti beta 2GPI) antibodies have been shown in animal models as not cross-reacting antibody populations. This observation prompted us to prove if anti-beta 2GPI exist in human sera by using a reliable method and then to investigate if these are independent from aCl antibodies. We have developed a new ELISA for the detection of anti-beta 2GPI antibodies employing the coating of the protein in carbonate buffer to irradiated microtitre plates and the filtration of serum samples, that makes irrelevant the binding to the uncoated wells. IgG F(ab)2 fragments from IgG positive sera were shown bind beta 2GPI, providing that the binding was a specific antibody binding, mediated by the antigen binding site of the antibody molecule: moreover the antibodies were not able to differentiate native and delipidated beta 2GPI coated plates, making a possible role of a phospholipid contaminant unlikely. On the other hand, the phosphorus content of native as well as delipitated beta 2GPI was undetectable. IgG, but not IgM, anti-beta 2GPI antibodies were classically inhibited by the addition of soluble beta 2GPI, while cardiolipin liposomes appear to modify the reaction in a completely different way, possibly by the described interaction between cardiolipin and beta 2GPI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Characterization of the endothelial surface proteins recognized by anti-endothelial antibodies in primary and secondary autoimmune vasculitis.

The antigenic structures recognized by anti-endothelial cell antibodies (AECA) in sera from 10 Wegener's granulomatosis (WG) and 12 systemic lupus erythematosus (SLE) patients with signs of vasculitis were characterized by immunoprecipitation of selectively radiolabeled surface membrane proteins from human umbilical vein endothelial cells. Electrophoretic analysis of the immunoprecipitated proteins revealed reactivities against endothelial antigens ranging in size from 200 to 25 kDa. AECA antigens were not cell specific, since the same sera also reacted, at least in part, with radiolabeled human fibroblast surface proteins. The majority of WG patients displayed a constant precipitation pattern of five proteins (180, 155, 125, 68, and 25 kDa). On the contrary, AECA from SLE sera reacted with a more heterogeneous series of endothelial proteins. A group of four proteins, however, was also found in the majority of SLE sera: 200, 180, 155, and 25 kDa. In addition, some endothelial antigens were immunoprecipitated only by WG (125 kDa) or by SLE sera (200 kDa), suggesting a different endothelial reactivity in different vasculitic processes. The reaction did not involve intracellular proteins as demonstrated by the lack of reactivity of SLE sera negative for AECA but positive for anti-cytoplasmic or anti-nuclear antibodies. These data confirming that AECA recognize surface endothelial determinants further support a potential pathogenetic role for these antibodies in autoimmune vasculitis.

Antibodies↗
PubMed1994

Immunization with anticardiolipin cofactor (beta-2-glycoprotein I) induces experimental antiphospholipid syndrome in naive mice.

Beta-2-GPI is a 50 kDa glycoprotein which is known to be a serum co-factor, with a role in determining the binding of pathogenic anticardiolipin antibodies to phospholipids. Immunization of naive mice with beta-2-GPI resulted in elevated levels of antibodies directed against negatively charged phospholipids (cardiolipin, phosphotidylserine, phosphatidylinositol). The presence of increased titres of antiphospholipid antibodies in the sera of the mice was later followed by prolonged activated partial thromboplastin time (APTT), thrombocytopenia, and when the mice were mated, by a high percentage of fetal resorptions in the uterus. These data point to the ability of beta-2-GPI to induce pathogenic anti-cardiolipin antibodies following active immunization.

Animals↗
PubMed1994

Central nervous system involvement in systemic lupus erythematosus: a new therapeutic approach with intrathecal dexamethasone and methotrexate.

In systemic lupus erythematosus (SLE), neurological involvement has been reported to occur with frequencies ranging from 14% (severe cases) to 83% (mild forms included). In spite of early diagnosis and aggressive treatment, neuropsychiatric SLE may represent a serious problem of management. We describe three cases, one with acute transverse myelitis, one with hemiparesis, and one with signs of focal and diffuse cerebral dysfunction, in whom improvement following intrathecal therapy with methotrexate and dexamethasone was observed.

Adolescent↗
PubMed1994

Anticardiolipin antibodies in infections are heterogenous in their dependency on beta 2-glycoprotein I: analysis of anticardiolipin antibodies in leprosy.

We studied the effect of beta 2-GPI on binding of antibodies in sera from patients with leprosy and patients with the antiphospholipid syndrome (APS) to CL in enzyme-linked immunosorbent assays (ELISAs). Increased levels of IgG aCL were detected in 59 of 61 leprosy patients' sera by the standard aCL-ELISA in the presence of bovine beta 2-GPI and in 60 of the 61 leprosy patients' sera by the modified aCL-ELISA without beta 2-GPI. When tested by both aCL-ELISAs on the same plate, 10/31 leprosy sera and 9/10 APS sera bound better in the standard aCL-ELISA, 16/31 leprosy sera bound better in the modified aCL-ELISA and in five leprosy and one APS sera the difference was not significant. A dose-dependent enhancing effect of beta 2-GPI on the leprosy and APS sera binding to CL was confirmed using purified human beta 2-GPI. Enhanced binding was seen if beta 2-GPI was added either before or together with the test serum. In 11/61 leprosy sera increased levels of IgG antibodies against beta 2-GPI were found by ELISA. Leprosy anti-beta 2-GPI antibodies appear to be a separate antibody population recognizing only beta 2-GPI adsorbed on the ELISA plate. These results demonstrate heterogeneity of leprosy aCL with respect to their beta 2-GPI requirement for binding to CL.

Antibodies, Anticardiolipin↗
PubMed1994

Antiphospholipid antibodies and risk of intrauterine late fetal death.

STUDY OBJECTIVE: Goal of the study was to analyze the relationship between anticardiolipin antibodies, lupus anticoagulant and the risk of intrauterine late fetal death. DESIGN: A case-control study was conducted in a network of general and teaching hospitals in northern Italy. Cases studied were 99 women (median age 27 years), without clinical evidence of systemic lupus erythematosus or other immunological disorders who had an 'unexplained' intrauterine fetal death at or after the 20 weeks of gestation. The control subjects were 85 women (median age 28 years) who gave birth at term (> 37 weeks gestation) to healthy infants on randomly selected days at the same hospitals where cases had been identified. RESULTS: The presence of lupus anticoagulant was detected in four of the 99 cases (4%, 95% confidence interval 2%-15%) and none of the 85 controls. A total of 10 out of the 89 cases (11%, 95 confidence interval 6%-23%), but none of the 79 controls for whom anticardiolipin antibodies value was available had elevated anticardiolipin antibodies; this difference was statistically significant (chi 2(1) = 9.38, p < 0.01).

Adolescent↗
PubMed1994

Beta 2 glycoprotein I and placental anticoagulant protein I in placentae from patients with antiphospholipid syndrome.

OBJECTIVE: To investigate the immunohistological distribution of beta 2-glycoprotein I (beta 2 GPI) and placental anticoagulant protein I (PAP-I) in normal and pathological placentae of patients with antiphospholipid (aPL) antibody associated recurrent fetal loss. These proteins are 2 natural anticoagulants able to interfere with aPL antibody binding. METHODS: Placentae from 4 patients with primary antiphospholipid antibody syndrome (pAPS), from 2 patients with aPL negative systemic lupus erythematosus (SLE) and from 7 healthy women were studied. Cryostatic placental sections were tested by indirect immunofluorescence using polyclonal anti-PAP-I and anti-beta 2GPI antisera as well as purified IgG and anti-beta 2GPI monoclonal antibody. The same tissue sections were also tested by direct immunofluorescence with FITC-F(ab)2 goat antihuman IgG. RESULTS: We found that (a) the placental distribution of PAP-I was comparable in normal and pathological specimens; (b) on the contrary, increased beta 2GPI deposition was present on the trophoblast surfaces of placentae obtained from patients with persistent raised titers of aPL antibodies. Comparable IgG deposition on villi surface was also found in aPL positive but not in control placentae. CONCLUSION: Our data are consistent with the hypothesis that high titer aPL binds to a beta 2GPI phospholipid complex in placentae of women with recurrent fetal loss but that a quantitative deficiency of PAP-I does not play a pathogenetic role in aPL associated fetal loss.

Adult↗
PubMed1994

Induction of experimental antiphospholipid syndrome in naive mice with purified IgG antiphosphatidylserine antibodies.

OBJECTIVE: It is accepted that antiphospholipid syndrome (APS) is due to the presence of anticardiolipin antibodies (aCL). Since phosphatidylserine is a negatively charged phospholipid, we tried to demonstrate the pathogenic role of antiphosphatidylserine in APS. METHODS: We used affinity purified IgG antiphosphatidylserine antibodies from sera of 2 patients with APS characterized by recurrent thromboembolic phenomena, recurrent fetal loss and prolonged activated partial thromboplastin time (aPTT). In one patient the antiphosphatidylserine Abs were the main antiphospholipid antibody (aPL) while the 2nd patient also had pathogenic aCL. The purified antibodies were passively infused into the tail vein of mice. The mice were mated and we followed them for manifestations of APS. RESULTS: Passive infusion of IgG but not IgM antiphosphatidylserine antibodies to pregnant ICR mice resulted in increased fetal resorption rate (40%), lower mean weights of the placentae and fetuses and prolonged aPTT (82 s). Antiphosphatidylserine antibodies were detected in the placentae. CONCLUSIONS: Our results point to the pathogenic role of antiphosphatidylserine antibodies and emphasize the importance of looking for the presence of antiphosphatidylserine Abs in sera of patients with clinical manifestations compatible with APS even in the absence of aCL Abs.

Abortion, Habitual↗
PubMed1993

ANCA with specificity for lactoferrin in systemic lupus erythematosus (SLE).

Antibodies to lactoferrin were detected in about 20% of patients with SLE, irrespective of the presence of renal involvement and in 10% of patients with rheumatoid arthritis and in 19% of patients with scleroderma. We conclude that anti-lactoferrin antibodies may be found in different types of connective tissue disease. Their clinical significance in these diseases however remains to be elucidated.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed1993

Prevention of fetal loss in experimental antiphospholipid syndrome by low-molecular-weight heparin.

OBJECTIVE: The purpose of this study was to compare the effectiveness of low-molecular-weight heparin with regular heparin in the prevention of fetal resorption in mice with the antiphospholipid syndrome. STUDY DESIGN: Antiphospholipid syndrome was passively induced in ICR mice by injecting them with anticardiolipin antibodies on the first day of pregnancy. Subsequently, these mice were treated with low-molecular-weight heparin in two different doses, with regular heparin, and with a placebo. On gestational day 17 the mice were killed by cervical dislocation, and the pregnancy outcome was evaluated. Statistical analysis was performed by means of a one-way analysis of variance using Bonferroni's t test. RESULTS: Treatment with low-molecular-weight heparin resulted in a resorption rate of 22.4% as opposed to 41.4% in mice with antiphospholipid syndrome that were given regular heparin and 51.7% in nontreated controls. CONCLUSION: We conclude that low-molecular-weight heparin can prevent fetal resorptions in mice with antiphospholipid syndrome.

Animals↗
PubMed1993

Clinical significance of antineutrophil cytoplasmic autoantibodies with specificity for lactoferrin in renal diseases.

The prevalence and clinical significance of antineutrophil cytoplasmic antibodies with specificity for lactoferrin was determined in patients with renal diseases. Antilactoferrin antibodies were found in only 12 of 920 patients (1.3%). These patients had either "pauci-immune" necrotizing crescentic glomerulonephritis (three cases) or lupus nephritis (nine cases). To verify whether antilactoferrin antibodies were specific for patients with systemic lupus erythematosus (SLE) and renal involvement, we studied 61 additional lupus patients, 40 with active lupus nephritis and 21 with active SLE and no renal involvement. Antilactoferrin antibodies were found in approximately 15% to 20% of patients with SLE, irrespective of the presence of renal involvement. We conclude that antineutrophil cytoplasmic antibodies with specificity for lactoferrin are only sporadically found in patients with renal diseases; these patients have either necrotizing crescentic glomerulonephritis or lupus nephritis. However, antilactoferrin antibodies are not a marker for renal involvement in SLE.

Adolescent↗
PubMed1993

Detection of anti-phospholipid and anti-DNA antibodies and their idiotypes in newborns of mothers with anti-phospholipid syndrome and SLE.

The titers, isotypes and idiotypes of antiphospholipid and anti-dsDNA antibodies were determined in seven pairs of mothers with antiphospholipid syndrome (APLS) and their offspring, in 11 pairs of SLE mothers and their matched infants and in seven respective pairs of healthy subjects. In addition, maternal as well as fetal sera were evaluated for the presence of anti-SSA (Ro), anti-SSB (La) and anti-70 kd RNP autoantibodies. In the sera from APLS patients, as well as in the sera from their offspring, the mean antibody titer of IgG aCL was found to be significantly higher then the corresponding value in the control group (P < 0.01). Highly significant increased titers of IgG anti-DNA antibodies were found in the sera of SLE mothers and their matched offspring (P < 0.0008). The prevalence of anti-SSA, anti-SSA, and anti-70Kd RNP antibodies was lower then that of antiphospholipid and anti-dsDNA antibodies. Only one of the respective offspring had increased levels of these antibodies. The quantity of maternal antibodies transferred to the fetus was depended on their concentration in the maternal circulation, as well as on their type and specificity. Follow-up of newborn sera showed a progressive decrease in the antiphospholipid antibody titers during 3 months. After 6 months it was undetected. Our results point to a transplacental transfer of aCL and anti-DNA antibodies, a phenomenon which is not necessarily associated with respective clinical manifestations, in contrast to the classical humoral mediated autoimmune diseases (e.g. myasthenia gravis).

Adult↗
PubMed1992

Antibodies to endothelial cells in primary vasculitides mediate in vitro endothelial cytotoxicity in the presence of normal peripheral blood mononuclear cells.

Twenty-eight out of 62 patients with Wegener's granulomatosis and micropolyarteritis display circulating antiendothelial cell antibodies (AECA) detectable by a cell surface radioimmunoassay. These antibodies do not induce an in vitro endothelial damage either alone or in the presence of fresh complement; however, 50% of IgG-AECA positive sera can be cytotoxic in the presence of human normal peripheral blood mononuclear cells (PBM) at high effector/target ratios. The specificity of the PBM-mediated cytotoxicity is supported by the absence of the phenomenon in AECA negative sera, by the disappearance of the lytic effect after absorption of AECA, and by the finding that cellular-mediated cytotoxicity can be reproduced by purified IgG-AECA positive fractions. On the contrary, polymorphonuclear leukocytes or adherent mononuclear cells are not involved in such a cytotoxic activity. AECA seem to be directed against determinants consitutively expressed on the endothelial surface since the activation of endothelial cells by interleukin-1 beta or interferon-gamma affects neither the antibody binding nor their ability to mediate 51Cr release in the presence of PBM. These findings favor the hypothesis for a possible direct pathogenetic role of circulating AECA in the in vivo vascular damage.

Adult↗