PubMed Health⌕ Search

Biomedical subjects

G Passiu

Publications and source records attributed to G Passiu.

53 records · Page 3Linked to original sources
PubMedDate not supplied

[The role of HLA-B27 molecules in the pathogenesis of ankylosing spondylitis].

Ankylosing Spondylitis (AS) is characterised by the strongest association with an HLA antigen ever described for any disease. It represents therefore the ideal model for the understanding of the link between immune-mediated diseases and the HLA system. The role of HLA-B27 in the pathogenesis of AS will be discussed focusing on the recently described higher expression of these molecules in patients with AS compared with healthy controls.

Amino Acid Substitution↗
PubMedDate not supplied

Takayasu's arteritis overlapping with systemic sclerosis.

We describe an unusual case of overlap between Takayasu's arteritis (TA) and systemic sclerosis (SSc). TA has been found in association with several diseases, but not with SSc. To our knowledge this is the first case report of TA associated with SSc in the literature. It is possible that the expression of the two diseases in our patient was influenced by the presence of genetic factors predisposing to both TA and SSc.

Adult↗
PubMedDate not supplied

Anti-cardiolipin antibody from a patient with antiphospholipid syndrome (APS) recognizes only an epitope expressed by cardiolipin/beta 2-glycoprotein-I (beta 2GPI) complex and induces APS.

OBJECTIVE: As the antiphospholipid syndrome (APS) is characterized by antibodies which bind negatively charged phospholipids either directly or mainly through different target epitopes located on the beta-2-glycoprotein-I (beta 2GPI) molecule, the aim of this study is to describe an additional target epitope for anti-cardiolipin binding. METHODS: The binding characteristics of affinity purified anti-cardiolipin antibodies from a patient with monoclonal gammopathy associated with clinically overt APS were studied; inhibition studies were also carried out. These antibodies were used for the active induction of experimental APS. RESULTS: The affinity purified anti-cardiolipin antibodies were found to bind a target epitope created by the complex of cardiolipin/beta 2GPI, while not reacting with a complex composed by another phospholipid (phosphatidylserine/beta 2GPI), as confirmed by direct binding and competition assays. Immunization of naive mice with this unique affinity purified anti-cardiolipin antibody resulted in the induction of experimental APS (thrombocytopenia, prolonged coagulation timed and fetal resorptions). The anti-cardiolipin/beta 2GPI injected mice developed high titers of mouse anti-cardiolipin/beta 2GPI antibodies with the same binding characteristics as the human antibody which was used for disease induction. CONCLUSION: APS is a unique syndrome that is characterized by a diversity of pathogenic anti-phospholipid antibodies which may explain the diversity of clinical manifestations reported in patients.

Aged↗
PubMedDate not supplied

[The current outlook in the therapy of autoimmune diseases].

Recent advances in immunology and molecular biology have contributed to a much greater understanding of the pathogenetic mechanisms of the autoimmune diseases and thus to the development of new rationally-based therapies. Most of the immunosuppressive agents that have been tried in autoimmune disease patients nonspecifically suppress the immune response, often causing various side effects. Autoimmune diseases result from the activation of self-reactive T cells that recognize autoantigens or foreign antigens cross-reactive with an autoantigen coupled with major histocompatibility complex (MHC) products on an antigen presenting cell. It appears possible to modulate T cell activation by interfering with the interaction between T cell receptor and the peptide-MHC molecule complex. A number of sites are potential targets for immunologic intervention, such as MHC molecules, T cell receptor, CD4 and CD3 molecules, adhesion molecules, cytokines and cytokine receptors. In the present review the most important new therapeutic approaches to autoimmune conditions, which appear to be more selective in overcoming the limitations of non-specific treatments, are summarized. They include monoclonal antibodies, cytokines and cytokine-inhibitors, peptides interacting with MHC molecules and T cell vaccination.

Antibodies, Monoclonal↗
PubMedDate not supplied

Collagenopathic cardiopathies.

Collagenopathic cardiopathies are a subject of extreme etiologic, pathogenetic and clinical interest. These disorders are associated with congenital or acquired anomalies of the connective tissue and because of the diffusion and nearly total distribution of this tissue, have a higher frequency than what has been previously estimated. The collagenopathic cardiopathies, can be divided into two main groups: one deriving from hereditary connective tissue diseases, and the other from acquired connective tissue diseases. The first group has a Mendelian type of transmission whereas the other appears to be secondary to various kinds of stimuli (viral, immunologic etc.) although polygenic factors are present. Of the first group we considered Marfan's syndrome, the Ehlers-Danlos syndrome, osteogenesis imperfecta, pseudoxanthoma elasticum, cutis laxa and the diseases of the fundamental substance with particular reference to mucopolysaccharidosis type 1H (Hurler's syndrome). In all of these disorders a specific metabolic disturbance is responsible for the cardiovascular damage which is expressed, depending on the specific genetic component in a more or less serious form. Among the acquired diseases of the connective tissue, we examined rheumatoid arthritis, systemic lupus erythematosus, polydermatomyositis, scleroderma; of the reactive arthritis, rheumatic fever; of the seronegative forms, spondyloarthritis, ankylosing spondylitis and Reiter's syndrome, mixed connective tissue disease and Lyme's disease. It must be emphasized that all of these disorders share relatively common pathogenetic characteristics which point to the importance of the presence of various types of antigens, immune complexes and the significant role of some of the histocompatibility antigens, as well as possible disturbances of cell-mediated immunity.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathies↗
PubMedDate not supplied

[Diffuse idiopathic skeletal hyperostosis of the cervical spine in a patient with ankylosing spondylitis. Description of a personal case].

Diffuse idiopathic skeletal hyperostosis (DISH) is a well-described disorder of middle-aged people, with a unique spinal pathology characterized by calcification and ossification of the antero-lateral aspect of at least four contiguous vertebral bodies, with the sparing of intervertebral spaces and sacroiliac joints. DISH has rarely been reported associated with ankylosing spondylitis (AS), a chronic inflammatory articular disease most commonly involving the spine and sacroiliac joints. A 63-year-old man with clinical and radiological findings of DISH with associated AS is described here. The authors conclude that these two diseases may, albeit rarely, coexist.

Cervical Vertebrae↗
PubMedDate not supplied

HLA antigens in Italian patients with systemic lupus erythematosus: evidence for the association of DQw2 with the autoantibody response to extractable nuclear antigens.

In order to verify the hypothesis that Italian patients with systemic lupus erythematosus (SLE) may be immunogenetically distinct from SLE patients born in other regions, we investigated the HLA class I and II antigens and their relation with the various autoantibodies characteristic of the disease in an Italian SLE population. Forty-four SLE patients were typed for HLA-A, -B, -C, -DR and -DQ antigens; sera from the same patients were tested for the presence of antibodies to the nuclear or cytoplasmic antigens Ro/SSA, La/SSB, Sm and RNP (ENA). Results of HLA typing showed that the frequencies of DR3 and DQw2 were increased in patients compared with controls. Analysis of the correlations between HLA antigens and anti-ENA antibodies showed that both DQw2 and DR3 were increased in patients with anti-Ro and/or antiLa antibodies, while in patients with anti-Sm and/or antiRNP antibodies the DQw2 and DR4 were found to be increased. Only DQw2 was found to be significantly increased in anti-ENA positive patients. These results might suggest that Italian patients with SLE are, at least in part, different from lupus patients living in other geographical areas and suggest the association of DQw2 with the autoantibody response to ENA in SLE.

Adult↗
PubMedDate not supplied

[Clinical manifestations correlated with anticardiolipin antibodies in systemic lupus erythematosus: preliminary results of a prospective study].

Antiphospholipid antibodies (aPL) have been linked to various clinical manifestations in systemic lupus erythematosus (SLE), mainly thrombosis, repeated abortions and thrombocytopenia. Despite the large number of studies which have been published in the recent years, there is still some debate on this matter, and no firm conclusion has been reached as yet. Among the various aPL, anticardiolipin antibodies (aCL) have received more attention, mostly because they can be easily detected by means of immunoenzymatic assays. The main objective of the present study was to determine the prevalence of IgG and IgM aCL isotypes in SLE in order to compare their possible association with the clinical manifestations of the disease. Clinical features of 40 consecutive and unselected SLE patients (35 female and 5 male) were prospectively studied. Sera from the same patients were tested for the presence of aCL, using a standardised ELISA assay, and the presence of aCL was correlated with the various clinical events. Results showed that the prevalence of aCL was 42.5% for the IgG isotype and 10% for the IgM isotype. Regarding the clinical associations of aCL, we found a strong linkage between the presence of these antibodies and the occurrence of both thrombosis and abortions; a weaker association with neurological events was also demonstrated. These results, if confirmed on larger series, suggest that aCL should be searched in patients with SLE in order to identify those who are at greater risk of developing some severe clinical problems and could benefit by prophylactic treatment.

Adult↗
PubMedDate not supplied

[Prognostic factors in Raynaud's phenomenon: usefulness of antinuclear antibodies and of periungual capillaroscopy].

Antinuclear antibodies (ANA) and nailfold capillary microscopy have been evaluated as prognostic markers in patients with apparently idiopathic Raynaud's phenomenon. Results have shown that either ANA and peculiar alterations in nailfold capillaries are important risk factors as regard to the evolution into a connective tissue disease; furthermore, when both these markers are present in a patient with Raynaud's phenomenon, the risk of evolution is even greater. When sensibility and specificity have been compared, ANA appeared to be a more sensible test but nailfold capillary microscopy seemed to be more specific. Our data suggest that ANA and capillary microscopy are important tests in patients with Raynaud's phenomenon; they should be performed in order to identify those patients who are at greater risk of evolving to overt connective tissue disease.

Adolescent↗
PubMedDate not supplied

Molecular and biochemical data on some glucose-6-phosphate dehydrogenase variants from southern Sardinia.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD; E.C.1.1.1.49) deficiency is the most common human enzymopathy; nearly 400 different biochemical variants of the enzyme have been described. Sardinia is the Italian region with the highest frequency of this defect. METHODS: We examined genomic DNA of 16 subjects with G6PD Mediterranean, 2 with G6PD Athens-like, 1 with G6PD Ferrara 2 (all as biochemically defined). RESULTS: All G6PD Mediterranean subjects had a C-->T mutation at nucleotide 563 and a C-->T transition at nucleotide 1311; G6PD Athens-like and Ferrara 2 subjects had a G-->C mutation at nucleotide 844 (the same mutation has been found in G6PD Seattle-like). CONCLUSIONS: This study suggests that in Southern Sardinia G6PD mutations are relatively homogeneous and that the results of biochemical characterization studies must be carefully evaluated, because the same mutations might be responsible for different biochemical behavior.

Genetic Variation↗
PubMedDate not supplied

Nerve growth factor and mast cell distribution in the skin of patients with systemic sclerosis.

Nerve growth factor (NGF), a well-characterized neurotrophic factor, induces an increase in the number of mast cells (MCs) in the peripheral tissues of developing rats, as well as histamine release in fully differentiated MCs. Since MCs increase in the dermis of patients with early systemic sclerosis (SSc), we examined the distribution of NGF in the skin of patients affected by SSc. Immunohistochemical studies showed that NGF distribution was more intense in the dermis of patients with SSc than in the skin of controls. A possible correlation between MCs and NGF in disease activity is hypothesized.

Adult↗