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Biomedical subjects

A Tincani

Publications and source records attributed to A Tincani.

At least 109 records · Page 6Linked to original sources
PubMed1990

Anti-endothelial cell antibodies in patients with Wegener's granulomatosis and micropolyarteritis.

Anti-endothelial cell antibodies (AECA) have been detected by cell surface radioimmunoassay in nine out of 15 patients with micropolyarteritis (MPA) and in two out of five patients with Wegener's granulomatosis. AECA mostly belonged to the IgG isotype and were present in the active phase of the diseases. These antibodies were not detectable in 10 sera from patients with essential mixed cryoglobulinaemia, suggesting that they were not a mere epiphenomenon consequent to the inflammatory vascular injury. The binding activity was not related to ABH antigens or to HLA class I antigens displayed by resting human endothelial cells in culture and was not influenced by removing immune complexes. Absorption of the anti-neutrophil cytoplasmic antibodies (ANCA), present in MPA and Wegener's granulomatosis sera, did not affect the endothelial binding. AECA-positive sera did not display lytic activity against endothelial cells, neither alone nor after addition of fresh complement or normal human peripheral blood mononuclear cells. Although AECA are not cytolytic for endothelial cell monolayers in vitro, the reactivity against intact endothelial cells suggests their possible involvement in in vivo pathological processes affecting vascular structures in small vessel primary vasculitides.

Adult↗
PubMed1990

Decreased number of peripheral blood CD4 + CD29+ lymphocytes and increased in vitro spontaneous production of anti-DNA antibodies in patients with active systemic lupus erythematosus.

Flow cytometric 2-color analysis of peripheral blood lymphocytes from patients with systemic lupus erythematosus (SLE) showed a reduction of relative and absolute number of CD4+ CD29+ cells compared to matched healthy individuals. This abnormality was more marked in patients with active/very active disease. Absolute number of CD4+ CD29+ cells was negatively correlated with spontaneous anti-DNA Ig production that we demonstrated to be a laboratory index strongly correlated with a clinical disease activity score. A decrease of the percentage of CD8+ CD29+ lymphocytes in patients with active disease was also observed.

Adult↗
PubMed1988

HLA-DR antigens and anticardiolipin antibodies in northern Italian systemic lupus erythematosus patients.

Eighty systemic lupus erythematosus (SLE) patients attending 3 clinical centers were evaluated immunologically and immunogenetically. No HLA class II antigens were found to be significantly associated with SLE in these patients. A highly significant (P = 6.17 x 10(-7) association was observed between anticardiolipin antibodies and DR7. A lesser association (P less than 0.025) was also observed between DR2 and/or DR3 and anti-Ro (SS-A) antibodies. No relationship was found between any DR antigen and anti-Sm/RNP, anti-double-stranded DNA, or anti-La (SS-B) antibodies.

Adolescent↗
PubMed1988

Autoantibodies and common idiotypes in men and women with sperm antibodies.

Antisperm antibodies have been implicated as a causative factor of infertility and pregnancy wastage. Since concomitant autoimmune phenomena were reported in men with antisperm antibodies, we investigated known antisperm antibody-positive sera from 25 women, 27 men, and the respective seminal plasma samples. The investigated autoimmune panel included a search for antinuclear antibodies, autoantibodies (in IgG, IgM and IgA isotypes) to seven phospholipids (cardiolipin, phosphatidylserine, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid), to four histone subfractions (H1, H2A, H3, H4), and to four polynucleotides [ssDNA, dsDNA, poly(I), and poly(dT)], total immunoglobulin levels, and sperm antibody titers. The sera were also evaluated for the presence of a common anti-deoxyribonucleic acid antibody, and anticardiolipin antibody idiotypes. Levels of sperm antibody titers were significantly lower in women than in men. Both men and women with antisperm antibodies demonstrated elevated total IgG levels compared with those of normal control subjects. Only women showed elevated levels of total IgM. Sera from 24% of women and 11% of men with antisperm antibodies demonstrated antinuclear antibody titers greater than 1:40. The most striking autoantibody abnormalities were found among antiphospholipid antibodies. Sera from women with antisperm antibodies demonstrated higher autoantibody production than was found in their male counterparts. A significant correlation was found between antisperm antibodies and IgM anticardiolipin and IgA anti-phosphatidylinositol in women and between sperm antibodies and IgA phosphatidylserine antibodies in men. The presence of anticardiolipin and anti-deoxyribonucleic acid antibody idiotypes was significantly more frequent in women than in men. By means of discriminant analysis and variables selected by this mathematical model, the identification of 24 of 25 women and 26 of 27 men with antisperm antibodies was correctly predicted. These results suggest that women and men respond differently to sperm antigens. The apparent cross-reactivity between sperm antibodies and other autoantibodies, usually associated with autoimmune disease, suggests that a polyclonal B cell activation, similar to that seen in autoimmune diseases, occurs in patients with sperm antibodies.

Adult↗
PubMed1988

Relationship between anti-cardiolipin and anti-endothelial cell antibodies in systemic lupus erythematosus.

Anti-endothelial cell antibodies (AECA) have been detected in 51 lupus sera by cell surface radioimmunoassay with a prevalence of 39.2% for IgG and 45.1% for IgM-AECA. No correlations were found between AECA and different clinical or laboratory parameters, including the presence of anti-cardiolipin antibodies and signs associated with the presence of anti-phospholipid antibodies. However, absorption with cardiolipin liposomes partially inhibited endothelial cell binding, and affinity purified anti-cardiolipin antibodies were able to react with intact human endothelial cells. The binding did not occur via Fc receptors since blocking of Fc receptors with rabbit IgG did not affect the endothelial cell reactivity. Taken together our findings support the hypothesis that antibodies directed against negatively charged phospholipids can be part of the anti-endothelial cell antibodies in certain lupus sera. The possible role of these cross-reacting antibodies in the pathogenesis of vascular thrombosis in lupus patients is discussed.

Antibodies↗
PubMed1987

Use of monoclonal antibodies to identify shared idiotypes on anticardiolipin and anti-DNA antibodies in human sera.

Using hybridoma technology we produced monoclonal antibodies (MoAb) to idiotypic determinants on human anti-cardiolipin antibodies purified from a patient with SLE. Hybridomas were screened by inhibition of cardiolipin binding activity of sera from patients with SLE. Seven hybridomas were selected, two of which were studied extensively. Sera from a number of patients with SLE were found to share idiotypic determinants. This cross-reacting idiotype was not detectable on anti-cardiolipin antibodies in syphilis sera. The cross-reacting idiotype was present in sera with anti-ssDNA antibodies even though some of these sera had no anti-cardiolipin antibodies. We propose that these MoAb may recognize a regulatory idiotype.

Animals↗
PubMed1987

Anti-mitochondrial type M5 and anti-cardiolipin antibodies in autoimmune disorders: studies on their association and cross-reactivity.

In a series of 42 positive sera, anti-mitochondrial type M5 antibodies (AMA-M5) were found most frequently in patients with SLE (24) and SLE-like syndromes. Patients with AMA-M5 displayed a higher prevalence of thrombocytopenia, thrombosis, biological false positive seroreactions for syphilis, lupus-like anticoagulant activity and anti-cardiolipin antibodies in comparison with a group of 43 SLE AMA-M5 negative patients. The strong association between anti-phospholipid and AMA-M5 antibodies cannot be explained entirely by cross-reactivity between these two groups of antibodies, as indicated by absorption experiments and studies using affinity purified antibody preparations. However, cardiolipin liposomes were able to reduce partially the titres of AMA-M5 sera, suggesting that a small population of AMA-M5 antibodies exists that cross-reacts with cardiolipin. The existence of this population was further substantiated by our demonstration that an IgM monoclonal antibody, from a patient with Waldenström's macroglobulinaemia, displayed both anti-cardiolipin and AMA-M5 activity, and AMA-M5 activity was completely inhibited by cardiolipin.

Adult↗
PubMed1985

Affinity purified anti-cardiolipin and anti-DNA antibodies.

Recent studies have raised questions concerning the specificity of anticardiolipin antibodies and their relationship to anti-DNA antibodies, the lupus anticoagulant, the biological false positive test for syphilis, and reagin, the antibody detected in syphilis. In an attempt to answer some of these questions, 3 IgG and 2 IgM affinity purified anticardiolipin antibodies, as well as 3 affinity purified anti-DNA antibodies were studied. Affinity purified anti-cardiolipin antibodies showed high binding to negatively charged phospholipids but not to ssDNA by solid phase radioimmunoassay. On the other hand, affinity purified anti-DNA antibodies did not bind cardiolipin. Inhibition experiments showed that negatively charged phospholipids and VDRL liposomes inhibited the binding of anticardiolipin antibodies to phosphatidylserine, but ssDNA, alpha-glycerol phosphate and hyaluronic acid did not. Similar studies of sera from patients with high anticardiolipin antibody levels supported the results obtained with affinity purified anticardiolipin antibodies. These results suggest that anticardiolipin antibodies bind negatively charged phospholipids and there appears to be little crossreactivity with DNA or unrelated negatively charged polymers such as hyaluronic acid. Both the negatively charged phosphodiester group and glyceride portions of the phospholipid molecules appear important for their antigenicity. Four of the 5 affinity purified anti-cardiolipin antibodies had lupus anticoagulant activity providing further evidence to suggest that these 2 groups of antibodies have the same or very similar specificities. Studies of sera from 3 patients with syphilis showed that VDRL liposomes inhibited reagin activity to a greater extent than did cardiolipin. On the other hand, in patients with autoimmune disorders, cardiolipin inhibited anticardiolipin antibody activity to a greater extent than did VDRL liposomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗
PubMed1984

Inhibitory effect of IgM rheumatoid factor on immune complex solubilization capacity and inhibition of immune precipitation.

Purified IgM rheumatoid factors (RF; 3 monoclonal and 2 polyclonal) were shown to inhibit, in a dose-dependent manner, 2 complement-mediated functions, i.e., the immune complex solubilization capacity and the inhibition of immune precipitation. Inhibition of immune complex solubilization capacity occurred only if RF was added at the same time as, but not after, addition of the complement source. Experimental evidence suggests that the effects of RFs were not related to their anticomplementary activity, but rather required the attachment of RF to the Fc region of the IgG molecule. Although no clinical data are available so far, it might be plausible that these newly described properties of RF have biologic relevance.

Antigen-Antibody Complex↗
PubMed1984

Anticardiolipin antibodies: occurrence in Behçet's syndrome.

Anticardiolipin antibodies have recently been described in association with arterial and venous thrombosis, and with neurological symptoms, in connective tissue diseases. In a study of 70 patients with Behçet's syndrome 13 patients had these antibodies. Of these 13 patients eight had a history of either retinal vascular pathology, cerebral infarction, or thrombophlebitis. The association of retinal vascular disease and the presence of anticardiolipin antibodies was statistically significant.

Antibodies↗
PubMed1983

Detection of circulating immune complexes in acute non-lymphatic leukaemia: is it reliable?

The in vivo and in vitro phagocytic ability of leukaemic cells and the serum levels of circulating immune complexes (CIC) have been evaluated in 11 patients affected by acute non-lymphatic leukaemia (ANLL). High levels of serum CIC were detected in 17% of the cases showing phagocytic ability and in 80% of the cases lacking phagocytic ability (p less than 0.05). In 3 patients serum CIC determinations were negative while immunoglobulins with complement-fixing ability were detected in the cytoplasm of leukaemic cells indicating in vivo phagocytosis of CIC. These results suggest that leukaemic cells may sometimes interfere through their phagocytic ability on the detection of CIC in the serum. Therefore, the clinical and prognostic value of serum CIC in ANLL seems questionable.

Antigen-Antibody Complex↗
PubMed1983

Con A suppressor cell assay: a further characterization.

Con A induced suppressor cell assay was further characterized in this study. Significant lower mitogenic responses of autologous fresh cells cocultured with Con A-activated cells were found when compared with the response of cocultures of responders plus control cells preincubated in medium alone. However, Con A-activated cells did not express a real suppression, since no difference was found between responses of fresh responders alone and responses of cocultures with Con A-activated cells. So, Con A activation seemed to block the expression of the enhancement provided by control cells to autologous responders, rather than to induce a real suppressor activity. The induction of the Con A suppressor cell activity required cell proliferation but it was not proportional to the degree of DNA synthesis. Monocyte depleted cell populations exhibited lower Con A suppressor cell activity compared to unfractionated cells, suggesting a cooperative role of monocytes in the Con A induction step. The expression of this activity was not due to a cytotoxicity against the responders and was dependent on the number of activated cells added. Mononuclear cells from active lupus erythematosus (SLE) patients, but not from inactive SLE patients differed from normal controls in showing a significant loss of suppression index.

Adult↗
PubMed1983

Solubilization of immune complexes and inhibition of immune precipitation in SLE sera.

The ability of serum to in vitro process immune complexes both preformed (ICSC) and during their formation (ICPIC) has been evaluated in 37 patients affected by systemic lupus erythematosus (SLE). ICSC was found to be significantly lower in these patients than in normal controls (p less than 0.001), and strictly related to the phase of the disease. Correlations were evidenced between ICSC and haemolytic activity of the classical and alternative pathways of complement, levels of the complement components C3 and C4, and incidence of circulating immune complexes. Low values of ICPIC were demonstrated almost only in sera of patients with active SLE; in fact, ICPIC was impaired in 6 sera only, and five of them were collected in the acute phase. All sera with decreased ICPIC also displayed a very low level of the C4 complement component.

Antigen-Antibody Complex↗