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Biomedical subjects

M G Sabbadini

Publications and source records attributed to M G Sabbadini.

At least 19 recordsLinked to original sources
PubMed2005

Takayasu's arteritis: A study of 104 Italian patients.

OBJECTIVE: Takayasu's arteritis (TA) is a rare vasculitis. The Italian Takayasu's Arteritis study group was established with the aim to describe a large cohort of patients. METHODS: Data were collected by means of an ad hoc form. Demographic information, clinical history, vascular findings, treatment, risk factors, and comorbidities were analyzed. RESULTS: Data of 104 patients were collected. The median delay in diagnosis was 15.5 months (range 0-325 months). Age at onset <15 years was associated with a higher probability, whereas elevated erythrocyte sedimentation rate with a lower probability, of a delay in diagnosis. The majority of patients experienced nonspecific signs and symptoms indicative of an inflammatory disease in the early phase. Among vascular involvement, stenosis was the most frequent lesion, being present in 93% of patients, followed by occlusion (57%), dilatation (16%), and aneurysm (7%). Glucocorticoids were the mainstay of treatment in our series; however, treatment with cytotoxic agents was required in about half of the patients. Fifty-two patients underwent at least 1 surgical procedure. The main indications for intervention were renal vascular hypertension, cerebral hypoperfusion, and limb claudication. CONCLUSION: As with many rare diseases, delay in diagnosis is an important issue for patients with TA. The increasing occurrence of vascular lesions along with the disease progression put to question the long-term effectiveness of contemporary treatment. These data may be helpful in increasing physicians' awareness to prevent diagnosis delay, update guidelines, and plan future research projects.

Adult↗
PubMed2005

Two single-nucleotide polymorphisms in the 5' and 3' ends of the osteopontin gene contribute to susceptibility to systemic lupus erythematosus.

OBJECTIVE: To test the association of osteopontin (OPN) polymorphisms with systemic lupus erythematosus (SLE). METHODS: The coding 5' and 3' flanking regions of the OPN gene were scanned for polymorphisms by denaturing high-performance liquid chromatography. A case-control association study was performed in 394 Italian SLE patients and 479 matched controls. OPN serum levels were determined by enzyme-linked immunosorbent assay in 40 patients and 124 controls, and the mean levels were compared between the different OPN genotypes. RESULTS: Among the 13 detected single-nucleotide polymorphisms (SNPs), alleles -156G (frequency 0.714 versus 0.651; P = 0.006, corrected P [P(corr)] = 0.036) and +1239C (0.377 versus 0.297; P = 0.00094, P(corr) = 0.0056) were significantly increased in the SLE patients compared with the controls. The presence of the associated allele in single or double dose conferred an odds ratio (OR) of 2.35 (95% confidence interval [95% CI] 1.38-4.02) for SNP -156 and an OR of 1.57 (95% CI 1.16-2.13) for SNP +1239. These effects were independent of each other, i.e., not a consequence of linkage disequilibrium between the 2 alleles. The risk associated with a double dose of susceptibility alleles at both SNPs was 3.8-fold higher (95% CI 2.0-7.4) relative to the complete absence of susceptibility alleles. With regard to individual clinical and immunologic features, a significant association was seen between lymphadenopathy and -156 genotypes (overall P = 0.0011, P(corr) = 0.046). A significantly increased OPN serum level was detected in healthy individuals carrying +1239C (P = 0.002), which is indicative of an association between the SLE susceptibility allele and OPN levels. CONCLUSION: These data suggest the independent effect of a promoter (-156) and a 3'-untranslated region (+1239) SNP in SLE susceptibility. We can speculate that these sequence variants (or others in perfect linkage disequilibrium) create a predisposition to high production of OPN, and that this in turn may confer susceptibility to SLE.

Disease Susceptibility↗
PubMed2005

Neurological involvement in rheumatological diseases.

Rheumatological diseases can involve the central and the peripheral nervous system in many ways. Every structure-the brain, meninges, spinal cord, cranial nerves, peripheral nerves-can be affected. Early recognition of neurological abnormality can help achieving diagnosis of the underlying condition and prevent permanent sensorimotor or cognitive function loss. This review focuses on the clinical presentation of the neurological involvement in rheumatological diseases.

Cognition↗
PubMed2004

Accumulation of plasma nucleosomes upon treatment with anti-tumour necrosis factor-alpha antibodies.

OBJECTIVE: Patients undergoing anti-tumour necrosis factor-alpha (TNF-alpha) treatment often develop autoantibodies. Apoptotic cell antigens are a potential initiating stimulus for autoantibodies. Our goal was to verify whether anti-cytokine therapy causes the release of nucleosomes, a major autoantigen generated during cell death. DESIGN: Laboratory research study with comparison group. SETTING: Clinical Immunology Unit and Lab, H San Raffaele University Hospital, Italy. SUBJECTS: Eleven healthy controls and 87 rheumatic patients were studied, including 51 with rheumatoid arthritis (RA) and 33 patients with systemic lupus erythematosus (SLE). INTERVENTIONS: Vein blood samples were taken via the antecubital vein. Blood was retrieved from 11 patients before and after injection of anti-TNF-alpha humanized antibodies. Nucleosomes were measured with an enzyme-linked immunosorbent assay. Cell death induced by anti-TNF-alpha antibodies and by the soluble cytokine was assessed in vitro. MAIN OUTCOME MEASURES: Nucleosome level by treatment. RESULTS: Enzyme-linked immunosorbent assay effectively detected nucleosomes either released by dying cells in vitro or circulating in the plasma. SLE but not RA patients had circulating nucleosomes at the steady state. Eight of 11 patients had significantly higher levels of plasma nucleosomes after infliximab. Minute amounts of TNF-alpha enabled infliximab to induce cell death in vitro. CONCLUSIONS: The accumulation of nucleosomes possibly fosters the development of autoantibodies in subjects with appropriate genetic backgrounds.

Adolescent↗
PubMed2002

Autoantibodies against a 72-kDa ductal cell membrane glycoprotein in a patient affected by Sjögren's syndrome and gastric MALT lymphoma.

Sjögren's syndrome is a chronic autoimmune disease affecting exocrine glands, resulting in xerostomia and xerophthalmia. Lymphocytic infiltration and fibrosis of exocrine glands as well as the presence of autoantibodies against organ-specific and non-organ-specific antigens are the hallmarks of the disease. We investigated whether some patients affected by Sjögren's syndrome might have autoantibodies directed against epithelial duct cell membrane proteins. We screened sera from patients affected by Sjögren's syndrome by indirect immunofluorescence on monkey salivary gland sections and FG-Met-2 cells (a pancreatic carcinoma cell line with ductal features) for the presence of antisalivary duct antibodies. Positive sera were employed in immunoprecipitation experiments on (35)S-methionine in vivo labeled and surface-biotinylated FG-Met-2 cells. The serum of a patient affected by Sjögren's syndrome and gastric mucosa-associated lymphoid tissue (MALT) lymphoma gave positive and distinct membrane immunostaining on FG-Met-2 cells. Immunoprecipitation with the patient's serum from (35)S-methionine-labeled cell extracts followed by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (PAGE) and autoradiography showed the presence of autoantibodies against a 72-kDa protein. After biotin-surface labeling of FG-Met-2 cells, a band with identical electrophoretic mobility was immunoprecipitated by the serum, demonstrating that the 72-kDa band is a membrane glycoprotein. We demonstrated by three complementary approaches, i.e., immunocytochemistry, (35)S-methionine in vivo labeling, and cell surface biotinylation, the presence of autoantibodies directed against a duct cell membrane protein of 72-kDa in a patient affected by Sjögren's syndrome and gastric MALT lymphoma. Autoantibodies directed against this novel membrane autoantigen may be an additional serological marker in some cases of Sjögren's syndrome.

Aged↗
PubMed2002

Association tests with systemic lupus erythematosus (SLE) of IL10 markers indicate a direct involvement of a CA repeat in the 5' regulatory region.

Many lines of evidence suggest that IL10 is a strong candidate gene for systemic lupus erythematosus (SLE) susceptibility. In our previously reported study an allele (IL10.G-140bp) of the microsatellite IL10.G located at position -1100 was significantly increased in Italian SLE patients in comparison with controls. Starting from this observation, we tested if sequence variations in the vicinity of IL10.G were more strongly associated with SLE. We performed a comprehensive association study including 26 SNPs (of which four were newly identified in the present study by DHPLC analysis) spanning 8.5 Kb of the 5' flanking and the transcribed region of the IL10 gene. The association study was performed by the DNA pool method on an extended panel of Italian patients (205) and controls (631). Haplotypic associations were studied by individual typing of seven selected markers surrounding IL10.G. Gene, genotype and haplotype frequencies were not significantly different in patients and controls. Thus the IL10.G microsatellite remains to date the only IL10 marker associated with SLE in our population. A meta-analysis of all published results indicates a possible direct role of the IL10.G repeat number in SLE susceptibility.

5' Flanking Region↗
PubMed2002

Clinical and serological associations of ribosomal P autoantibodies in systemic lupus erythematosus: prospective evaluation in a large cohort of Italian patients.

OBJECTIVE: To verify the association of ribosomal anti-P antibodies (anti-P), as detected by a sensitive ELISA, with serological findings and clinical manifestations, including neuropsychiatric involvement evaluated according to the American College of Rheumatology (ACR) nomenclature, in a large cohort of patients with systemic lupus erythematosus (SLE). METHODS: Anti-P were evaluated in the serum of 149 consecutive Italian SLE patients by an ELISA using a multiple antigen peptide carrying four copies of a common P0, P1 and P2 epitope. A complete laboratory evaluation and clinical examination were performed in each patient. In addition, all patients underwent an accurate neuropsychiatric and neuropsychological assessment performed by trained specialists according to the 1999 ACR suggestions. RESULTS: Serum anti-P were detected in 18/149 patients (12.1%). The anti-P prevalence was similar (11.7%) when the analysis was performed in a larger series of sera including 82 additional SLE patients, who were not included in the clinical study. The age of anti-P-positive patients at disease onset was less than 33 yr and, in comparison with the anti-P-negative patients, these patients showed more active disease activity and a higher prevalence of photosensitivity and malar and discoid rash. A strong association between IgG anticardiolipin antibodies and anti-P was also found. However, anti-P were associated with neither neuropsychiatric syndromes nor cognitive impairment. CONCLUSION: This study does not seem to confirm the described association of anti-P with SLE neuropsychiatric manifestations. However, it supports the anti-P association with different skin manifestations as well as the presence of anticardiolipin in a subset of patients with SLE characterized by early disease onset.

Adolescent↗
PubMed2001

PTX3 in small-vessel vasculitides: an independent indicator of disease activity produced at sites of inflammation.

OBJECTIVE: To verify whether the prototypical long pentraxin PTX3 represents an indicator of the activity of small-vessel vasculitis. METHODS: Concentrations of PTX3, a pentraxin induced in endothelium by cytokines, were measured by enzyme-linked immunosorbent assay in the sera of 43 patients with Churg-Strauss syndrome, Wegener's granulomatosis, and microscopic polyangiitis. PTX3 was also measured in the sera of 28 patients with systemic lupus erythematosus (SLE), 22 with rheumatoid arthritis, and 16 with CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasias). Serum concentrations of C-reactive protein (CRP) were measured by immunoturbidimetry. The cells involved in PTX3 production in vivo were identified in skin biopsy samples. RESULTS: Patients with active vasculitis had significantly higher concentrations of PTX3 than did those with quiescent disease (P < 0.001). PTX3 levels in the latter group were similar to those in healthy controls. PTX3 levels were higher in patients with untreated vasculitis and lower in patients who underwent immunosuppressive treatments (P < 0.005). In contrast, patients with active SLE had negligible levels of the pentraxin. PTX3 levels did not correlate with CRP levels in vasculitis patients. Endothelial cells produced PTX3 in active skin lesions. CONCLUSION: PTX3 represents a novel acute-phase reactant produced at sites of active vasculitis.

Acute Disease↗
PubMed2001

Anti-beta2 glycoprotein I antibodies cause inflammation and recruit dendritic cells in platelet clearance.

Scavenger phagocytes are mostly responsible for the in vivo clearance of activated or senescent platelets. In contrast to other particulate substrates, the phagocytosis of platelets does not incite proinflammatory responses in vivo. This study assessed the contribution of macrophages and dendritic cells (DCs) to the clearance of activated platelets. Furthermore, we verified whether antibodies against the beta2 Glycoprotein I (beta2GPI), which bind to activated platelets, influence the phenomenon. DCs did not per se intemalise activated platelets. In contrast, macrophages efficiently phagocytosed platelets. In agreement with the uneventful nature of the clearance of platelets in vivo, phagocytosing macrophages did not release IL-1beta, TNF-alpha, or IL-10, beta2GPI bound to activated platelets and was required for their recognition by anti-beta2GPI antibodies. DCs internalised platelets opsonised by anti-beta2GPI antibodies. The phagocytosis of opsonised platelets determined the release of TNF-alpha and IL-1beta by DCs and macrophages. Phagocytosing macrophages, but not DCs, secreted the antiinflammatory cytokine IL-10. We conclude that anti-beta2GPI antibodies cause inflammation during platelet clearance and shuttle platelet antigens to antigen presenting DCs.

Antibodies↗
PubMed2000

The long pentraxin PTX3 binds to apoptotic cells and regulates their clearance by antigen-presenting dendritic cells.

Pentraxins are acute-phase proteins produced in vivo during inflammatory reactions. Classical short pentraxins, C-reactive protein, and serum amyloid P component are generated in the liver in response to interleukin (IL)-6. The long pentraxin PTX3 is produced in tissues under the control of primary proinflammatory signals, such as lipopolysaccharide, IL-1 beta, and tumor necrosis factor-alpha, which also promote maturation of dendritic cells (DCs). Cell death commonly occurs during inflammatory reactions. In this study, it is shown that PTX3 specifically binds to dying cells. The binding was dose dependent and saturable. Recognition was restricted to extranuclear membrane domains and to a chronological window after UV irradiation or after CD95 cross-linking-induced or spontaneous cell death in vitro. PTX3 bound to necrotic cells to a lesser extent. Human DCs failed to internalize dying cells in the presence of PTX3, while they took up normally soluble or inert particulate substrates. These results suggest that PTX3 sequesters cell remnants from antigen-presenting cells, possibly contributing to preventing the onset of autoimmune reactions in inflamed tissues. (Blood. 2000;96:4300-4306)

Acute-Phase Reaction↗
PubMed2000

Anti-beta2 glycoprotein I antibodies prevent the De-activation of platelets and sustain their phagocytic clearance.

Exposure to phosphatidylserine (PS) tags dying and senescent cells for removal and identifies activated platelets. In this study we followed the fate of PS-exposing platelets in the presence of antibodies purified from Systemic Lupus Erythematosus (SLE) and primary Anti-phospholipid Syndrome (APS) patients' sera by beta2GPI affinity chromatography. Thrombin-activated platelets exposed PS and associated to beta2GPI. Both events were required for recognition by antibodies. Human monocyte-derived macrophages phagocytosed activated platelets only. Each macrophage internalized an average of 3.16+/-0.2 platelets after 60 min at 37 degrees C. Phagocytosis did not increase after longer incubations (4.65+/-0.26 platelets internalized by each macrophage after 300 min). Recognition of platelets by anti-beta2GPI antibodies significantly increased phagocytosis (P< 0.01). Upon withdrawal of thrombin, platelets downregulated PS (PS exposure t(1/2): 242 min) and the ability to be recognized by macrophages. Purified beta2GPI bound to PS-exposing platelets (association t(1/2): 250 min). Phosphatidyl serine exposure and beta2GPI association had virtually identical kinetics. Antibody binding prolonged the exposure of the beta2GPI/PS complex (t(1/2): >1200 min). The ability to phagocytose opsonized platelets was accordingly sustained (5.3+/-0.2 opsonized platelets were internalized by each macrophage after 60 min and 9.4+/-0.3 after 300 min). Anti-beta2GPI antibodies therefore poise activated platelets in a PS-exposing status, preventing the recycling of their function and favoring their phagocytic clearance.

Antibodies↗
PubMed2000

Budd-Chiari syndrome in a patient with ulcerative colitis: association with anticardiolipin antibodies.

This is the first reported case of a young patient with ulcerative colitis who developed acute Budd-Chiari syndrome and was found positive for anticardiolipin antibodies. Although an association between ulcerative colitis and Budd-Chiari syndrome, and between the latter and antiphospholipid antibodies, has been shown in the literature, the coexistence of these three conditions has never been reported. The patient we describe did poorly and was considered as a candidate for liver transplantation in spite of prompt heparin therapy, probably because of the presence of multiple risk factors.

Adult↗
PubMed2000

Thymoma associated with systemic lupus erythematosus and immunologic abnormalities.

The association between Systemic Lupus Erythematosus (SLE) and thymoma occurs with a greater frequency than dictated by coincidence alone. The immunologic effects of thymectomy on the appearance and/or the course of SLE are still to be elucidated. We report one case of SLE diagnosed at the same time as thymoma, and two cases of thymoma associated with immunologic disorders in the absence of clinical signs and symptoms diagnostic of SLE.

Adult↗
PubMed2000

Apoptosis and systemic autoimmunity: the dendritic cell connection.

Much effort has been devoted in recent years to the events linking recognition and disposal of apoptotic cells to sustained immunity towards the antigens they contain. Programmed death via apoptosis indeed provides most of the raw material the immune system exploits to establish self tolerance, i.e. to learn how to distinguish between self constituents and foreign antigens, belonging to invading pathogens. In parallel, events occurring during cell death may enable a restricted array of molecules endowed with diverse structure, function and intracellular distribution to satisfy the requirement to evoke and maintain autoimmune responses. Dendritic cells (DCs), the most potent antigen presenting cells, appear to play a crucial role. Here we will discuss some of the constrains regulating the access of dying cells' antigens to DCs, as well as censorship mechanisms that prevent their maturation and the full explication of their antigen presenting function.

Animals↗