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Biomedical subjects

C Lunardi

Publications and source records attributed to C Lunardi.

At least 19 recordsLinked to original sources
PubMed2005

In chronic idiopathic urticaria autoantibodies against Fc epsilonRII/CD23 induce histamine release via eosinophil activation.

BACKGROUND: Chronic idiopathic urticaria is a common skin disorder characterized by recurrent, transitory, itchy weals for more than 6 weeks. An autoimmune origin has been suggested based on the findings of auto-antibodies (Abs) directed against either the alpha subunit of the high-affinity IgE receptor or the IgE molecule in nearly half of the patients. OBJECTIVE: To identify other autoantigen targets in patients with chronic idiopathic urticaria. METHODS: We used pooled IgG derived from 133 patients with chronic idiopathic urticaria to screen a random peptide library to identify disease-relevant autoantigen peptides. Among the identified peptides, one was recognized by the vast majority of patients' sera. Abs against this peptide were affinity purified from the patients' sera and assayed for their ability to induce histamine release from basophils. RESULTS: We identified a peptide that showed similarity with the low-affinity IgE receptor (Fc epsilonRII/CD23) expressed on lymphomonocytes and eosinophils. Anti-peptide IgG Abs purified from the patients' sera bound cell surface CD23 and were able to induce histamine release from basophils. This effect appeared to be mediated by the release of major basic protein from eosinophils upon engagement of CD23. The same effects were obtained with the sera from mice immunized with the CD23 peptide. CONCLUSION: Our results indicate that patients with chronic idiopathic urticaria have Abs against CD23 and that eosinophils, which infiltrate the skin of these patients, play a crucial role in maintaining the disease through the release of major basic protein upon engagement of the low-affinity IgE receptor by such auto-Abs.

Adolescent↗
PubMed2004

Efficacy of intravenous immunoglobulin in chronic idiopathic pericarditis: report of four cases.

Human intravenous immunoglobulins (hIVIgs) are used in two broad categories of diseases: immunodeficiency and autoimmunity. Among the immune-mediated diseases hIVIgs are of benefit in idiopathic thrombocytopenic purpura, autoimmune hemolytic anemia, and dermatomyositis. Chronic idiopathic pericarditis (CIP) is a chronic disease of unknown origin characterized by recurrent episodes of pericardial inflammation. The cause of the recurrence is unknown, although in some cases it may be traced to a viral infection and to the presence of antimyocardial antibodies. Since a viral infection can induce an autoimmune process through a mechanism of molecular mimicry, and since the optimal therapy for prevention of the recurrences has not been established, we reasoned that treatment with hIVIgs could be beneficial in our patients unresponsive to previous immunosuppressive therapies. We describe four patients affected by CIP treated with monthly high-dose hIVIgs (0.4 g/kg daily for 5 consecutive days) for five times followed by administration every 2 months. Three of the four patients could permanently discontinue steroid therapy and are still in remission after years of follow-up. Our experience suggests that hIVIgs therapy may be a useful and safe treatment for CIP in steroid-dependent patients.

Adult↗
PubMed2002

In vivo activated T cells in rheumatoid synovitis. Analysis of Th1- and Th2-type cytokine production at clonal level in different stages of disease.

T-cell cytokines play a crucial role in the pathogenesis and progression of rheumatoid arthritis (RA). Their detection in the joint, however, is impaired by the complex network present in the synovium. Although many synovial T cells show signs of previous activation, only a few express interleukin (IL)-2 receptor, marker of recent activation. The aim of this study was to analyse the cytokine production by in vivo activated (IL-2R +) T cells from RA at different stages of the disease. For this purpose, T cells were isolated from peripheral blood and synovial fluid of four patients with active RA, two at the onset of the disease, one in the early phase during treatment, one in long-lasting chronic phase. One patient was studied at the onset of the disease and 52 months later. Cells were initially expanded with a low dose of IL-2, cloned and analysed for cytokine production. The results showed a strong predominance of T helper (Th) 1 clones in the blood and a slight prevalence of Th0 clones in the joint of all the four patients. Interferon-gamma and IL-2 production was higher in the long-lasting RA, whereas IL-4 synthesis was prevalent in early RA. Enrichment in IL-10-producing clones was present only in the joint of the untreated patients. The longitudinal study confirmed the differences in cytokine production between early and late phases of disease. These data confirm that RA is mainly a Th1-driven condition. However, in vivo activated synovial T cells produce also Th2-type anti-inflammatory cytokines, such as IL-4 and IL-10. The synthesis of both cytokines is a feature of the very early phase of RA, although the selective recruitment of IL-10-producing T cells is quickly lost.

Adult↗
PubMed2001

DNase I mediates internucleosomal DNA degradation in human cells undergoing drug-induced apoptosis.

Internucleosomal DNA fragmentation following the activation of endonucleases is the common end point of apoptosis. DNase I, a Ca(2+) / Mg(2+)-dependent endonuclease ubiquitously expressed in mammalian tissues, is believed to play a role in this process. To analyze the in vivo function of this enzyme in human cells, we have generated a cell line with targeted disruption of the DNase I gene, as well as several stable cell lines which overexpress the DNase I gene. Inactivation of the human DNase I gene was obtained in the Jurkat T cell clone JA3, characterized by high susceptibility to apoptotic cell death induced by pharmacological stimuli. JA3 cells, after disruption of the DNase I gene, became resistant to apoptotic stimuli. DNase I was overexpressed in the human cell lines JA3, K562 (erythroleukemia), M 14 (melanoma) and CEM (T cell lymphoma). Remarkably, stable overexpression of DNase I gene resulted in accelerated apoptosis in JA3 cells and induced apoptosis in K562, CEM and M14 cell lines, which are otherwise resistant to internucleosomal DNA degradation following pharmacological stimuli. Our study provides the first in vivo evidence that DNase I mediates internucleosomal DNA degradation in human cells undergoing drug-induced apoptosis.

Apoptosis↗
PubMed2001

A 1.1-kb duplication in the p67-phox gene causes chronic granulomatous disease.

Chronic granulomatous disease (CGD) is a rare inherited immunodeficiency that is caused by a functional defect of the NADPH oxidase of phagocytes, and that leads to severe recurrent infections. CGD results from the absence or the dysfunction of various components of NADPH oxidase, and autosomal recessive CGD with the lack of p67-phox (A67 CGD) is the rarest form of the disease. Identifying familiar mutations in subjects with A67 CGD provides the most reliable method of detecting carriers and is the basis for prenatal diagnosis. In the present study, we report the detailed characterization of the first duplication in the p67-phox gene identified in a 30-year-old patient affected by systemic aspergillosis attributable to p67-phox deficiency. We show that this new mutation involving exons 9 and 10 is the result of a tandem duplication of approximately 1.1 kb, which resulted from the juxtaposition of intron 8 to intron 10. We have sequenced both the junction fragment of this duplication and the corresponding wild-type regions and have found that the breakpoint regions in intron 8 and in intron 10 show limited homology. Our result suggests that this interchange arose as an illegitimate recombination event. As in other non-homologous rearrangements previously reported, the duplication breakpoints are located within the sequence motif 5'-CCAG-3' and its complement 5'-CTGG-3'.

Adult↗
PubMed2001

Food allergy and seronegative arthritis: report of two cases.

The link between food allergy and arthritis is still a matter for debate. Here we report two cases of patients suffering from arthritis sustained by food allergy. Diagnosis was performed on the basis of a 2-week elimination diet followed by an open and double-blind challenge test which was repeated three times. Both patients had a previous medical history of food allergy/intolerance. As the number of patients with joint complaints sustained by food allergy is very small it makes no sense to put all patients on diet. A previous medical history of food intolerance is one of the main reasons to start the long and difficult path towards a diagnosis of food allergy.

Adult↗
PubMed2001

Role of CD30+ T cells in rheumatoid arthritis: a counter-regulatory paradigm for Th1-driven diseases.

CD30 has been proposed to identify Th0/2-type clones. However, the in vivo relevance of this finding is still a matter of debate, as high serum levels of soluble CD30 have been found in both Th1- and Th2- dominated disorders. Among these, rheumatoid arthritis represents a condition where the Th1 predominance is combined with the presence of CD30(+) T-cell activity, particularly in specific stages of the disease. This article discusses the hypothesis that CD30(+) T cells might play a counter-regulatory role at sites of inflammation in Th1-mediated conditions, such as rheumatoid arthritis.

Animals↗
PubMed2000

CD30+ T cells in rheumatoid synovitis: mechanisms of recruitment and functional role.

High serum levels of soluble CD30 (sCD30) have been reported to better predict the response to second line therapy in rheumatoid arthritis (RA). It is believed that sCD30 is released by CD30+ T cells present in the RA synovium. However, both the mechanism of recruitment to the joint and the functional role of this T cell subset in the pathogenesis of the disease remain unknown. This study confirmed higher levels of sCD30 in the serum and synovial fluid (SF) of RA patients compared with normal controls. However, analysis of mRNA and cell surface CD30 expression showed that CD30+ T cells are detectable in the SF, but not in the synovial membrane. In contrast, T cells expressing the CD30 transcript, but not the surface molecule, were found in the peripheral blood of both RA and normal controls. CD30 surface expression was up-regulated by adhesion and migration through endothelium in vitro and in a delayed-type hypersensitivity model in vivo. Although the great majority of fresh or cloned CD30+ T cells from SF produced both IFN-gamma and IL-4, CD30 expression strictly correlated with IL-4 synthesis in synovial T cell clones. In addition, CD30+ T cell clones also produced high amounts of the anti-inflammatory cytokine IL-10. On this basis, we would like to propose that synovial CD30+ cells may play a role in the control of the inflammatory response. Serum sCD30 may reflect such cell activity and, therefore, explain the previously demonstrated correlation between high sCD30 serum levels and positive response to therapy.

Adult↗
PubMed2000

Analysis of CIITA encoding AIR-1 gene promoters in insulin-dependent diabetes mellitus and rheumatoid arthritis patients from the northeast of Italy: absence of sequence variability.

Qualitative and/or quantitative alterations in the expression of the MHC class II molecules affect the onset and maintenance of the immune response and may be the basis of a wide variety of disease states, such as autoimmunity and immunodeficiency.CIITA is a major physiological regulator of the expression of MHC class II genes. The availability of CIITA ap- pears generally essential for MHC class II gene expression, and hence its own transcriptional regulatory mechanisms result of fundamental importance for a correct homeostasis of the immune response. Therefore, it is possible to hypothesize that variability at the CIITA-encoding locus, AIR-1, could constitute an additional source of susceptible traits to autoimmune diseases. Mutations at AIR-1/CIITA promoters could modulate expression of CIITA. Variations in CIITA expression could influence the qualitative and quantitative expression of MHC class II molecules at cell surface. We have analyzed sequence variation at AIR-1/CIITA promoters by PCR-SSCP in 23 IDDM and 30 RA patients compared to a sample of 19 unaffected normal controls and 16 unaffected IDDM family members, for a total of 88 Caucasian subjects from the Northeast of Italy. No sequence difference was found at the four AIR-1/CIITA promoters between autoimmune patients and normal controls. Moreover, the promoters resulted invariant within the entire group of 88 subjects analyzed, comprising patients and controls. This finding suggests a possible selective advantage in maintaining CIITA upstream regulatory sequences invariant.

Arthritis, Rheumatoid↗
PubMed2000

Systemic sclerosis immunoglobulin G autoantibodies bind the human cytomegalovirus late protein UL94 and induce apoptosis in human endothelial cells.

Systemic sclerosis is an autoimmune disease characterized by immunological and vascular abnormalities. Autoantibodies against intracellular antigens are associated with particular clinical features of the disease, whereas autoantibodies against cell surface antigens may be pathogenic by inducing endothelial cell damage, considered the primary event in the pathogenesis of the disease. Latent human cytomegalovirus infection may contribute to progression of systemic sclerosis through its ability to infect endothelial cells; however, direct links between human cytomegalovirus infection and systemic sclerosis are still lacking. Molecular mimicry is one of the mechanisms that account for the link between infection and autoimmunity. Here we have identified an immunodominant peptide using systemic sclerosis serum screening of a random peptide library; such peptide shares homology with autoantigens and with the human cytomegalovirus late protein UL94 (ref. 9). Immunoglobulin G antibodies against the peptide affinity-purified from the sera of patients with systemic sclerosis specifically recognized the viral product and autoantigens; moreover, such antibodies induced endothelial cell apoptosis through specific interaction with the cell surface integrin-NAG-2 protein complex. Our results provide evidence that antibodies against human cytomegalovirus cause apoptosis of endothelial cells, considered the initial pathogenic event of systemic sclerosis, and indicate a previously unknown mechanism for the etiological link between human cytomegalovirus infection and autoimmunity.

Apoptosis↗
PubMed2000

Serum level of soluble intercellular adhesion molecule 1 in patients with chronic liver disease related to hepatitis C virus: A prognostic marker for responses to interferon treatment.

Intercellular adhesion molecule 1 (ICAM-1) is a marker of inflammation and tissue damage. Levels of soluble ICAM-1 (sICAM-1) were measured in 71 patients with chronic C hepatitis treated with interferon (IFN)-alpha-2a, at baseline and at every 3 months of therapy, and in 42 normal control subjects. The levels of sICAM-1 were significantly higher in the patient than in the control subject group, particularly among cirrhotics. Baseline sICAM-1 levels were similar in responders and nonresponders. By contrast, the concentration of sICAM-1 decreased significantly only in responders during the first 3 months of therapy. The probability of response to treatment, analyzed by Kaplan-Meier analysis, was much higher in the group showing a decrease of sICAM-1 than in the patients who did not show such a decrease. In conclusion, a "longitudinal" evaluation of serum levels of sICAM-1 in the first period of treatment is particularly useful in the identification of patients with high significant probability of response to treatment.

Adolescent↗
PubMed2000

Glycine-rich cell wall proteins act as specific antigen targets in autoimmune and food allergic disorders.

Our objective was to investigate the presence of a B and T cell immune response directed against the glycine-rich cell wall protein (GRP) in patients with different autoimmune disorders and with food allergy. GRP is an ubiquitous food protein that has high homology with cytokeratins and other self proteins [Epstein-Barr virus nuclear antigen-1 (EBNA-I), heterogeneous nuclear ribonucleoprotein, fibrillar collagen] which are common targets in autoimmune disorders. A peptide (GGYGDGGAHGGGYGG) derived from GRP was used to screen human sera in direct and competitive ELISA assay. Anti-GRP-specific IgG were analyzed for their ability to cross-react with autoantigens. The intracellular cytokine profiles of the peptide-specific T cell clones obtained from representative patients have been studied. BALB/c mice were immunized with the peptide coupled to the carrier protein keyhole limpet hemocyanin (KLH). Serum IgG antibodies directed against the GRP peptide were detected in several autoimmune disorders and in food allergic patients, and were able to cross-react with autoantigens including keratin, collagen and EBNA-I. Twenty-five T cell clones showed a specific proliferative response to the GRP peptide and were of the T(h)0 phenotype. Eight of the 10 BALB/c mice immunized with the peptide coupled to KLH developed an autoimmune response. Our data suggest that phylogenetically highly conserved epitopes in plants, viruses and humans may be responsible for an autoimmune response in susceptible individuals. They also indicate that the antigen spreading of a particular sequence among apparently divergent proteins may participate to initiate or amplify an immune response.

Amino Acid Sequence↗
PubMed1999

Expression of plasminogen activator inhibitor-1 in human adipose tissue: a role for TNF-alpha?

Elevated plasminogen activator inhibitor-1 (PAI-1) plasma levels, responsible for reduced fibrinolysis, are associated with animal and human obesity and with increased cardiovascular disease. The expression of PAI-1 has been found recently in animal and human adipose tissue. Factors and mechanisms regulating such an expression remain to be elucidated. In omental and/or subcutaneous biopsies from obese non-diabetic patients, incubated in Medium 199, we have confirmed that human adipose tissue expresses PAI-1 protein and mRNA; furthermore we have demonstrated that such an expression is clearly evident also in collagenase isolated human adipocytes and that it is stimulated by incubation itself and enhanced by exogenous human tumor necrosis factor-alpha (h-TNF-alpha). Since human adipose tissue produces TNF-alpha, to further characterize the relationship of PAI-1 to TNF-alpha, human fat biopsies were also incubated with Pentoxifylline (PTX) or Genistein, both known to inhibit endogenous TNF-alpha through different mechanisms. PTX caused a dose-dependent decrease of basal PAI-1 protein release, reaching 80% maximal inhibitory effect at 10(-3)M, the same inhibitory effect caused by Genistein at 100 microg/ml. This was associated to a marked inhibition of PAI-1 mRNA and of endogenous TNF-alpha production. Furthermore, when human fat biopsies were incubated in the presence of polyclonal rabbit neutralizing anti-human TNF-alpha antibody (at a concentration able to inhibit 100 UI/ml human TNF-alpha activity), a modest but significant decrease of the incubation induced expression of PAI-1 mRNA was observed (19.8+/-19.0% decrease, P = 0.04, n = 7). In conclusion, the results of this study demonstrate that PAI-I expression is present in human isolated adipocytes and that it is enhanced in human adipose tissue in vitro by exogenous TNF-alpha. Furthermore our data support the possibility of a main role of endogenous TNF-alpha on human adipose tissue PAI-1 expression. This cytokine, produced by human adipose tissue and causing insulin resistance, may be a link in the clinical relationship between insulin-resistance syndrome and increased PAI-1 plasma levels.

Adipose Tissue↗
PubMed1999

Soluble CD30 in early rheumatoid arthritis as a predictor of good response to second-line therapy.

OBJECTIVE: To evaluate whether serum levels of the soluble form of CD30 (sCD30) correlate with disease activity in early rheumatoid arthritis (RA) and may have prognostic value in predicting the response to disease-modifying anti-rheumatic drugs (DMARDs). METHODS: The levels of sCD30 and C-reactive protein (CRP) were measured in the serum of 14 untreated subjects with early RA, before and during treatment with hydroxychloroquine, for a follow-up period of 8 months. At the end of the study, patients were also evaluated for their response to DMARDs. RESULTS: An inverse correlation between sCD30 and CRP serum values was demonstrated at baseline, but not during the follow-up. Patients who responded to DMARD therapy had higher sCD30 basal levels than non-responders. CONCLUSIONS: The evaluation of sCD30 serum levels in early RA may reflect the attempt by CD30+ T cells to downmodulate inflammation and may be a useful marker to predict a good response to DMARDs.

Adult↗
PubMed1999

Autonomic nervous system dysfunction in sclerodermic and primary Raynaud's phenomenon.

Our aim was to investigate the sympathetic hyperactivity of systemic sclerosis that may lead to greater morbidity and mortality from cardiovascular events. We analysed the sympathetic (low-frequency) and vagal (high-frequency) components of heart rate variability, in supine and upright positions, in 10 patients with systemic sclerosis, 12 patients with primary Raynaud's phenomenon and 14 controls. We also analysed lung function in order to evaluate a possible link between heart rate variability and ventilation parameters. Heart rate variability was reduced in the supine position in subjects with systemic sclerosis both in comparison with primary Raynaud's phenomenon (total power: 1103+/-156 versus 3302+/-486 ms2, P<0.004) and control subjects (3148+/-422 ms2, P<0.002). Low-frequency power was higher in patients with systemic sclerosis than in the controls (54.5+/-4.5 versus 42.5+/-3.5 normalized units, P<0.01). During tilt, the change in heart rate was +44% in controls, +24% in subjects with primary Raynaud's phenomenon, and only +17% in the patients with systemic sclerosis (P<0.01 versus controls). In patients with systemic sclerosis we found a significant correlation between high-frequency power and the indices of lung function (residual volume: r2=0.5143, P<0.01; total lung capacity: r2=0.5142, P<0.01, vital capacity: r2=0.3789, P<0.05). Heart rate variability was reduced and sympathetic output increased in patients with systemic sclerosis. Subjects with primary Raynaud's phenomenon were characterized by normal heart rate variability and by some degree of sympathetic hyperactivity. During tilting, subjects with systemic sclerosis maintained an unmodified heart rate variability, thus suggesting an impaired baroceptor modulation of the autonomic control. The negative correlation between high-frequency power and indices of respiratory insufficiency in patients with systemic sclerosis suggests that the pulmonary structure plays an important role in the modulation of heart rate variability.

Adult↗
PubMed1998

Chronic parvovirus B19 infection induces the production of anti-virus antibodies with autoantigen binding properties.

Human parvovirus B19 infection in adults shows some clinical features similar to those found in autoimmune connective tissue diseases. To better clarify the relationship between viral infection and autoimmunity, we have evaluated the ability of anti-parvovirus antibodies to specifically recognize autoantigens in ten patients with chronic symmetric arthritis resembling rheumatoid arthritis or with recurrent episodes of arthritis and cutaneous manifestations and persistence of specific IgM antibodies against B19 parvovirus. We synthetized a 24-amino acid immunodominant peptide corresponding to a part of the virus protein 1 and virus protein 2 overlapping region. The peptide has been used to test patients' sera at different time points with an enzyme-linked immunosorbent assay (ELISA) and to purify anti-virus antibodies by affinity chromatography on a peptide-Sepharose column. Eluted immunoglobulins recognized the B19 peptide in both direct and competitive ELISA. Affinity-purified anti-parvovirus antibodies were then tested on a panel of autoantigens including human keratin, collagen type II, thyreoglobulin, single-strand (ss)DNA, cardiolipin and ribonucleoprotein antigen Sm. Eluted antibodies specifically recognized keratin, collagen type II, ssDNA and cardiolipin. Autoantibody activity was not detected in the immunoglobulin fraction after complete removal of anti-peptide antibodies and in antibodies eluted from normal donors. Epstein-Barr virus-transformed cell clones obtained from two subjects produced antibodies which simultaneously recognize the viral peptide and several autoantigens. To further confirm the role of the virus in inducing an autoantibody response, eight BALB/c mice were immunized with the viral peptide coupled to a carrier protein. Autoantibody activity against keratin, collagen II, cardiolipin and ssDNA was detected in six of the eight mice which developed a strong anti-virus response. Together, these data indicate that B19 parvovirus may be linked to the induction of an autoimmune response.

Adolescent↗