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N Del Papa

Publications and source records attributed to N Del Papa.

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

Antiphospholipid antibodies cross-reacting with erythrocyte membranes. A case report.

We describe a patient with primary antiphospholipid syndrome (PAPS) and haemolytic anemia with cryoagglutinins, in whom antibodies eluted from red blood cells (RBC) displayed anti-cardiolipin (CL) binding activity. This activity was confined to the IgG isotype and was directed to the negatively-charged phospholipids only. In addition, the patient's IgG fraction displayed a higher binding to RBC in comparison to normal control IgG and this reactivity was inhibited after absorption of the anti-CL activity with CL-micelles. These findings further sustain the association between antiphospholipid antibodies (APA) and Coombs' positivity with or without haemolytic anemia and suggest that APA could be at least in part responsible for anti-RBC activity.

Aged↗
PubMedDate not supplied

CD69 expression on neutrophils from patients with rheumatoid arthritis.

OBJECTIVE: Since the early activation antigen CD69 has been implicated in the pathogenesis of some inflammatory diseases, we evaluated the expression of the molecule on peripheral blood (PB) and synovial fluid (SF) neutrophils obtained from RA patients and its possible correlation with PB and SF cytokine concentration. METHODS: CD69 membrane expression (and CD11b as control marker) was assessed by indirect immunofluorescence and flow cytometry analysis on purified PB and SF neutrophils. Cytokine levels (GM-CSF, IFN-gamma, TNF-alpha) in plasma and SF supernatants were measured by ELISA. RESULTS: CD69 was absent on control neutrophils, while it was expressed on PB neutrophils from RA patients although no detectable GM-CSF, IFN-gamma or TNF-alpha was observed in their plasma. CD69 expression was still more evident on SF neutrophils from RA patients; 59% had detectable levels of INF-gamma in their SF while GM-CSF and TNF-alpha were detectable in SF from 95% and 33% of RA patients, respectively. However, no correlation was observed between cytokine concentrations and CD69 expression on SF neutrophils. SF but not PB neutrophils from RA patients expressed increased amounts of CD11b when compared to control PB neutrophils without any correlation with CD69 membrane expression. CONCLUSION: The activation antigen CD69 is significantly expressed on PB and SF neutrophils from RA patients. However, the mechanism(s) of induction and its possible role in the pathogenesis of RA remain to be defined.

Adolescent↗
PubMedDate not supplied

Autoantibodies to chromatin: prevalence and clinical significance in juvenile rheumatoid arthritis.

OBJECTIVE: To determine the prevalence of anti-chromatin antibodies (Abs) in juvenile rheumatoid arthritis (JRA) and to assess any association between the presence of anti-chromatin Abs and clinical subsets of the disease. METHODS: IgG anti-chromatin Abs and anti-extractable nuclear antigens (ENA) Abs were detected by an enzyme-linked immunosorbent assay (ELISA), and antinuclear Abs (ANA) by indirect immunofluorescence in sera of 89 children with JRA. Ten children with systemic, 32 with polyarticular and 47 with pauciarticular disease onset (uveitis occurred in 17/47 children) were studied. As a control group, 12 sera of patients suffering from idiopathic uveitis and 31 age- and-sex-matched healthy children (HC) were examined. RESULTS: Abs to chromatin were detected in 14/47 (29.8%) of children suffering from pauciarticular onset JRA and in this group the higher prevalence of anti-chromatin Abs has been found in children with chronic uveitis (p = 0.002). Anti-chromatin positivity was observed in 2/10 (20%) of systemic and in 3/32 (9.3%) of polyarticular onset JRA. Furthermore, none of the patients with idiopathic uveitis and HC had Abs to chromatin. anti-chromatin Abs titers remained relatively stable over a 6-month control period. CONCLUSION: Our results confirm previous data about the presence of circulating anti-chromatin Abs in juvenile arthritis. Interestingly, anti-chromatin Abs were significantly higher in the group of patients with pauciarticular onset with past or present history of uveitis, than in patients without ocular involvement. A long-term follow-up study could be useful to demonstrate the potential utility of these autoantibodies in diagnosing, classifying and treating children affected.

Antibodies, Antinuclear↗
PubMedDate not supplied

Relationship between anti-phospholipid and anti-endothelial cell antibodies: further characterization of the reactivity on resting and cytokine-activated endothelial cells.

Sera positive for autoimmune anti-phospholipid antibodies were studied by a cell surface radioimmunoassay for their cross-reactivity with resting or activated human endothelial cells. The endothelial cell activation by interleukin 1 beta, gamma-interferon, lipopolysaccharide or phorbol-12 myristate-13 acetate did not affect the cross-reactivity. Comparable findings were also found by testing anti-cardiolipin affinity purified preparations. Taken together these data indicate that endothelial cell activation is not sufficient per se to modulate the expression of antigenic determinants recognizable by the anti-phospholipid antibodies. However, anti-cardiolipin affinity purified preparations displayed enhanced cell binding after cell membrane perturbation by paraformaldehyde fixation, suggesting that an alteration in endothelial cell integrity might further trigger the reaction of circulating anti-phospholipid antibodies with vessel walls in vivo.

Antibodies↗
PubMedDate not supplied

Anti-Ro/SSA antibodies in rheumatoid arthritis: clinical and immunologic associations.

OBJECTIVE: To assess the prevalence of anti-Ro/SSA in RA and to analyse clinical and serological features of anti-Ro/SSA positive patients with RA. METHODS: 195 consecutive patients affected by RA were studied by counterimmunoelectrophoresis and ELISA for the detection of anti-Ro/SSA antibodies. Anti-Ro were found in 12 patients, with a prevalence of 6%. These 12 patients were pooled with other 15 patients known to have anti-Ro/SSA antibodies and RA, in order to evaluate their clinical and laboratory features. RESULTS: Anti-Ro positive patients showed a common pattern of joint involvement at onset and a comparable progression of disease compared to anti-Ro negative subjects. In addition, extra-articular manifestations (such as xerophthalmia, xerostomia, scleritis, oral ulcers and amyloidosis) and peculiar autoantibody profile (hypergammaglobulinemia, anti-dsDNA and AMA) were found significantly associated to anti-Ro/SSA positivity. Even though DMARDs withdrawals were more frequently detected in anti-Ro/SSA patients, especially when using gold salts, no statistical difference between the two groups was detected. In addition, anti-TNFalpha treatment did not cause further progression of autoimmunity neither on laboratory nor on clinical ground. CONCLUSION: Anti-Ro/SSA can be detected in about 6% of patients affected by RA. These patients presented a peculiar clinical picture characterised by extra-articular manifestations some of which are known to be anti-Ro/SSA correlated, while others are more disease-specific (amyloidosis, episcleritis). Anti-Ro/SSA are significantly associated with other autoantibodies not specific for RA such as anti-dsDNA and AMA. Treatment with anti-TNF drugs did not cause further progression of autoimmunity neither on laboratory nor on clinical ground.

Amyloidosis↗
PubMedDate not supplied

Relationship between anti-phospholipid and anti-endothelial cell antibodies III: beta 2 glycoprotein I mediates the antibody binding to endothelial membranes and induces the expression of adhesion molecules.

OBJECTIVE: To investigate the role of antibodies reacting with beta 2 glycoprotein I (beta 2GPI) in the antiendothelial cell binding activity present in sera from patients with the anti-phospholipid syndrome. METHODS: Sera positive for anti-phospholipid, anti-endothelial and anti-beta 2 GPI antibodies were studied for their binding activity on endothelial monolayers cultured in the presence or absence of media containing bovine serum as a source of beta 2GPI. Anti-endothelial activity was also evaluated on endothelial cells cultured without serum and supplemented with exogenous human purified beta 2GPI. Affinity purified anti-beta 2 GPI antibodies were investigated under the same experimental conditions. Finally, the effect of the incubation of these affinity purified fractions on the expression of adhesion molecules (ELAM-1) was studied. RESULTS: The reactivity of the sera decreased on endothelial cells incubated in serum-free medium, while endothelial cell binding was restored in a dose dependent manner after the addition of exogenous purified human beta 2 GPI. Affinity purified anti-beta 2 GPI antibodies obtained from the same sera retained their endothelial cell binding and were able to activate endothelial cells by inducing the ex novo surface expression of adhesion molecules (ELAM-1). CONCLUSIONS: These findings indicate that the close association between anti-endothelial and anti-phospholipid antibodies is sustained by antibodies which recognize beta 2 GPI adhering to the endothelial cells, and can promote their activation.

Antibodies, Antiphospholipid↗
PubMedDate not supplied

What is the pathogenetic role of antiphospholipid antibodies?

The association between antiphospholipid antibodies (aPL) and arterial or venous thrombosis, fetal loss and thrombocytopenia defines the so-called "antiphospholipid syndrome" (APS). Despite serial studies in recent years, a clear pathogenetic mechanism(s) has not yet been demonstrated. Several authors have investigated the interaction between aPL and the membranes of blood cells (endothelial cells and platelets) involved in coagulation. aPL is also thought to affect the balance between the procoagulant and anticoagulant states by interacting with plasma or tissue cofactors. Finally, the strong association between aPL and experimental animal models of fetal loss supports a direct pathogenetic role for aPL in inducing a poor pregnancy outcome in APS women.

Abortion, Spontaneous↗
PubMedDate not supplied

Anti-neutrophil cytoplasmic antibodies in patients with chromomycosis.

OBJECTIVE: Antineutrophil cytoplasmic antibodies (ANCA) are a family of antibodies that react to proteins within neutrophil granules and monocyte lysosomes, and occur prominently in sera from patients with systemic necrotizing vasculitis. The cytoplasmic staining pattern (c-ANCA) is very sensitive and specific for Wegener's granulomatosis (WG), and most commonly results from reactivity with proteinase 3 (PR3). The features of tissue damage in the fungal infection chromomycosis, in particular polymorphonuclear neutrophil (PMN) infiltration and granuloma formation, bear a resemblance to that seen in WG. METHODS: We tested sera from 25 patients with clinical and histologic diagnosis of chromomycosis for the presence of ANCA by indirect immunofluorescence. These same sera were analyzed for reactivity to neutrophil primary granule extracts and PR3 by ELISA. RESULTS: Five of the 25 patients (20%) had detectable c-ANCA, without central accentuation, at serum dilutions of at least 1:40. Three of these 5 ANCA-positive patients reacted with neutrophil primary granule extracts by ELISA; however, none of them reacted with PR3. CONCLUSIONS: These results demonstrate that fungal infection should be included among the conditions, unrelated to necrotizing vasculitis, that can trigger autoreactivity against myeloid lysosomal antigens.

Adult↗
PubMedDate not supplied

Anti-endothelial cell antibodies in systemic sclerosis: significant association with vascular involvement and alveolo-capillary impairment.

OBJECTIVE: To assess the frequency of antiendothelial cell autoantibodies (AECAs) in a group of patients with systemic sclerosis (SSc) and possible associations with clinical and serologic features of the disease. METHODS: Sera from 50 patients with SSc (38 with the limited and 12 with the diffuse form) were screened for AECA (ELISA). The reference limits were were 56.6% for the IgM isotype and 3.3.5% for the IgG isotype. AECA results were analyzed in relation to lung involvement (chest x-ray, high resolution computed tomography (HRCT), ventilation scintiscan with radioaereosol (DTPA), pulmonary pressure (echodoppler technique): heart involvement (EKG, 24 hr ambulatory EKG, echocardiography), cutaneous involvement (skin score), capillaroscopic characteristics and digital ulcers. AECA were also correlated with the erythrocyte sedimentation rate (ESR), anticentromere (ACA) and antitopoisomerase I (ATA) autoantibodies, and angiotensin converting enzyme plasma levels (ACE). RESULTS: The AECA IgG prevalence was 40% (22/50) for the SSc group as a whole, without significant differences between subsets. A significant negative correlation was shown between the AECA and ACE plasma levels in both subsets. In the diffuse form, a significant positive correlation was found between AECA and ESR and significant associations were found between AECA and the parameters reflecting alveolo-capillary involvement (DLco, DTPA), the pulmonary artery pressures, digital ulcers and capillaroscopic abnormalities. No statistically significant correlations were found between AECA and heart involvement, the skin score or pulmonary interstitial fibrosis. CONCLUSIONS: These data suggest that in SSc the anti-endothelial cell antibodies are directly linked to vascular injury and could reflect endothelial damage. Further studies are needed to verify whether AECA might identify a subgroup of patients at higher risk for the development of vascular crises and whether they might therefore be considered a predictor of outcome in SSc patients.

Autoantibodies↗