Antonio Puccetti - Academia.edu (original) (raw)

Papers by Antonio Puccetti

Research paper thumbnail of Molecular mimicry as a mechanism of induction of autoantibodies

Autoimmunity: Experimental Aspects, 1994

Research paper thumbnail of Autoimmunity and infection in common variable immunodeficiency (CVID)

Autoimmunity Reviews, 2016

Common variable immunodeficiency (CVID) is a heterogeneous group of diseases, characterized by pr... more Common variable immunodeficiency (CVID) is a heterogeneous group of diseases, characterized by primary hypogammaglobulinemia. B and T cell abnormalities have been described in CVID. Typical clinical features of CVID are recurrent airway infections; lymphoproliferative, autoinflammatory, or neoplastic disorders; and autoimmune diseases among which autoimmune thrombocytopenia (ITP) is the most common. The coexistence of immunodeficiency and autoimmunity appears paradoxical, since one represents a hypoimmune state and the other a hyperimmune state. Considering both innate and adaptive immune response abnormalities in CVID, it is easier to understand the mechanisms that lead to a breakdown of self-tolerance. CD21(low) B cells derive from mature B cells that have undergone chronic immune stimulation; they are increased in CVID patients. The expansion of CD21(low) B cells is also observed in certain autoimmune diseases. We have studied CD21(low) B cells in patients with CVID, CVID, and ITP and with ITP only. We observed a statistically significant increase in the CD21(low) population in the three pathological groups. Moreover, we found statistical differences between the two groups of CVID patients: patients with ITP had a higher percentage of CD21(low) cells. Our data suggest that CD21(low) cells are related to autoimmunity and may represent a link between infection and autoimmunity.

Research paper thumbnail of Chronic parvovirus B19 infection induces the production of antivirus antibodies with autoantigen binding properties

Immunol Lett, 1997

Poster presentations patients had a histoly of venous thrombosis and 11 female patients had a his... more Poster presentations patients had a histoly of venous thrombosis and 11 female patients had a history of soontaneous abortions.

Research paper thumbnail of Antibody associated with autoimmune pancreatitis and uses thereof

Research paper thumbnail of Serum DNase I, soluble Fas/FasL levels and cell surface Fas expression in patients with SLE : a possible explanation for the lack of efficacy of hrDNase I treatment

International Immunology, Jan 15, 2009

The objectives of the study are to evaluate DNase I serum levels and their correlation with solub... more The objectives of the study are to evaluate DNase I serum levels and their correlation with soluble Fas (sFas) and soluble Fas ligand (sFasL) and with cell surface Fas expression in patients with systemic lupus erythematosus (SLE), thus contributing to the dysregulated apoptosis typical of the disease. The methods include the following: Serum DNase I levels in patients and in controls were detected using the dot blot method and quantified by densitometry; sFas and sFasL were quantified using an ELISA system. Cell surface Fas expression was evaluated by FACS analysis. Apoptosis was studied by means of internucleosomal DNA degradation using a commercially available kit. The results are as follows: We found a significant difference in DNase I, sFas and sFasL serum levels between patients and controls. Levels of DNase I <7.79 ng ml 21 are more represented in patients with SLE. Active SLE is strongly associated with high sFas levels and detectable sFasL. DNase I does not correlate with sFas or sFasL, whereas it correlates with T cell surface Fas expression that is higher in patients with active SLE than in healthy controls. Finally, administration of exogenous human recombinant DNase (hrDNase) I to freshly isolated T cells up-regulates cell surface Fas expression and induces increased susceptibility to Fas-mediated apoptosis. In conclusion, our findings confirm that DNase I is low in SLE and suggest that it may play a role in apoptosis in SLE by regulating the surface expression of the cell death molecule Fas. This role may contribute to explain the inefficacy of hrDNase I in SLE, a treatment proposed for the ability of DNase I to remove DNA from auto-antigenic nucleoprotein complexes.

Research paper thumbnail of Alleli HLA-DRB1 e artrite reumatoide nel nord Italia: assenza di correlazione con la gravità delta malattia e con manifestazioni extra-articolari

Recenti Progressi in Medicina, 2005

Riassunto. Abbiamo studiato la frequenza degli alleli HLA-DRB1 in 101 pazienti affetti da artrite... more Riassunto. Abbiamo studiato la frequenza degli alleli HLA-DRB1 in 101 pazienti affetti da artrite reumatoide (AR) e in 229 soggetti sani con il metodo della reazione a catena della polimerasi e ibridizzazione oligonucleotide-specifica. Abbiamo osservato una ...

Research paper thumbnail of The role of peptide libraries in the identification of novel autoantigen targets in autoimmune diseases

Discovery Medicine, Mar 1, 2010

Identification of pathogenetically relevant autoantigen targets is a major goal in the study of a... more Identification of pathogenetically relevant autoantigen targets is a major goal in the study of autoimmune diseases. Indeed it may allow the development of new specific diagnostic tools and facilitate the understanding of the pathogenesis of a disease in order to individualize possible novel treatments. The random peptide library is a molecular biology method that consists of the display of random peptides on live microorganisms. The screening of the library with pooled immunoglobulins obtained from patients affected by an autoimmune disease may lead to the identification of novel autoantigens and of antibodies that are able to bind such antigens with high affinity. Testing patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; sera for the presence of these antibodies may be helpful in the diagnosis of the disease. Moreover such antibodies can be investigated for their functional activity and therefore provide new insights into the pathogenesis of the disease.

Research paper thumbnail of Plant-Derived Chimeric Virus Particles for the Diagnosis of Primary Sjögren Syndrome

Frontiers in plant science, 2015

Plants are ideal for the production of protein-based nanomaterials because they synthesize and as... more Plants are ideal for the production of protein-based nanomaterials because they synthesize and assemble complex multimeric proteins that cannot be expressed efficiently using other platforms. Plant viruses can be thought of as self-replicating proteinaceous nanomaterials generally stable and easily produced in high titers. We used Potato virus X (PVX), chimeric virus particles, and Cowpea mosaic virus, empty virus-like particles to display a linear peptide (lipo) derived from human lipocalin, which is immunodominant in Sjögren's syndrome (SjS) and is thus recognized by autoantibodies in SjS patient serum. These virus-derived nanoparticles were thus used to develop a diagnostic assay for SjS based on a direct enzyme linked immunosorbent assay format. We found that PVX-lipo formulations were more sensitive than the chemically synthesized immunodominant peptide and equally specific when used to distinguish between healthy individuals and SjS patients. Our novel assay therefore allo...

Research paper thumbnail of Dextran-specific IgG response in hypersensitivity reactions to measles-mumps-rubella vaccine. Authors' reply

The Journal of Allergy and Clinical Immunology, Jan 12, 2008

Research paper thumbnail of Gene Expression Profiling in Peripheral Blood Mononuclear Cells of Patients with Common Variable Immunodeficiency: Modulation of Adaptive Immune Response following Intravenous Immunoglobulin Therapy

Plos One, May 15, 2014

Background: Regular intravenous immunoglobulin treatment is used to replace antibody deficiency i... more Background: Regular intravenous immunoglobulin treatment is used to replace antibody deficiency in primary immunodeficiency diseases; however the therapeutic effect seems to be related not only to antibody replacement but also to an active role in the modulation of the immune response. Common variable immunodeficiency is the most frequent primary immunodeficiency seen in clinical practice.

Research paper thumbnail of A method for retracing the putative antigen/antibody ratio of immune complexes in biological fluids

Clinical and experimental rheumatology

It is well known that immune complex (ICs) diseases are caused by a number of factors which influ... more It is well known that immune complex (ICs) diseases are caused by a number of factors which influence the localization, clearance and inflammatory potential of ICs. Several studies suggest that the Ag/Ab ratio is one of the most important of these. Previous studies have clarified that IC detection methods which differ, either in their recognition unit or in the phase used (solid or liquid), show a very poor correlation with each other. This study was developed in order to verify the hypothesis that different methods recognise different kinds of ICs on the basis of their Ag/Ab ratio. We used 3 homogeneous EIAs employing a probe complex enzyme--anti enzyme which competes with circulating ICs for the recognition unit (bovine conglutinin, C1q or monoclonal rheumatoid factor) to detect 10 unrelated in vitro-made ICs at different relative Ag/Ab concentrations (from 8 x Ag excess to 8 x Ab excess). We demonstrated that the 3 recognition units recognised the ICs principally on the basis of their Ag/Ab ratio. These results were then used to set up a mathematical model capable of retracing the Ag/Ab ratio of the ICs present in unknown samples. This was employed to test a panel of sera from patients with systemic lupus erythematosus, essential mixed cryoglobulinemia and rheumatoid arthritis; we obtained very suggestive results but they require further prospective studies to understand the full significance of this parameter.

Research paper thumbnail of Human and murine anti-DNA antibodies induce the production of anti-idiotypic antibodies with autoantigen-binding properties (epibodies) through immune-network interactions

The Journal of Immunology

To examine the potential role of immune-network interactions in the production of lupus autoantib... more To examine the potential role of immune-network interactions in the production of lupus autoantibodies, normal NZW rabbit antibody responses were analyzed after immunization with one of the following Ig preparations: human lupus serum anti-dsDNA antibodies, human lupus serum anti-ssDNA antibodies, a mixture of human lupus serum anti-dsDNA and anti-ssDNA antibodies, the MRL-lpr/lpr anti-dsDNA mAb H241, and the MRL-lpr/lpr anti-ssDNA mAb H130. Four of five rabbits produced Ig typical of lupus autoantibodies: individual rabbit Ig cross-reacted with multiple autoantigens including nucleic acids, cardiolipin, SmRNP, glomerular extract, laminin, and exogenous Ag. Rabbit anti-Id against human anti-dsDNA antibodies were highly specific for dsDNA. Notably, in each serum the autoantibody activity was confined to the anti-Id Ig fraction. A similar spontaneously occurring Id-anti-Id interaction was also found between anti-ssDNA and anti-dsDNA antibodies isolated from an individual lupus patient. These results indicate that lupus autoantibodies which share Ag binding properties with pathogenic Ig, including both cross-reactive and anti-dsDNA antibodies, can induce the production of Ig with similar autoantigen binding properties through immune-network interactions. This phenomenon, if unregulated, could lead to the amplification of pathogenic autoantibody production in individuals with systemic lupus.

Research paper thumbnail of An immunoglobulin light chain from a lupus-prone mouse induces autoantibodies in normal mice

Journal of Experimental Medicine

Research paper thumbnail of Immune complex behaviour during prolonged plasma exchange in essential mixed cryoglobulinemia and systemic lupus erythematosus

The International journal of artificial organs

A number of immunological parameters were measured in 9 patients with essential mixed cryoglobuli... more A number of immunological parameters were measured in 9 patients with essential mixed cryoglobulinemia and 12 patients with systemic lupus erythematosus undergoing plasma exchange alone or without cytotoxic drugs. Only cryocrit significantly decreased in the majority of patients with essential mixed cryoglobulinemia. In contrast, immune complex levels, measured in two different ways, did not change on the whole, although variable and unpredictable changes were often present in individual patients. Thus, these data do not support the view that the mechanism(s) of action of plasma exchange in these diseases is only due to the quantitative removal of circulating immune complexes, and qualitative changes in the immune complex moiety may also occur.

Research paper thumbnail of Calcinosis universalis in systemic sclerosis with limited scleroderma

Clinical and experimental rheumatology

Research paper thumbnail of The T cell receptor repertoire in psoriatic synovitis is restricted and T lymphocytes expressing the same TCR are present in joint and skin lesions

The Journal of Rheumatology

To investigate the T cell receptor (TCR) repertoire in psoriatic synovitis and to determine wheth... more To investigate the T cell receptor (TCR) repertoire in psoriatic synovitis and to determine whether T lymphocytes in joint and skin lesions show the same Vbeta CDR3 region. The expression of Valpha and Vbeta families was evaluated by reverse transcriptase-polymerase chain reaction. The CDR3 region of some Vbeta families was analyzed by cloning and sequencing. We found a diverse variable beta chain usage within psoriatic synovial fluid of 11 patients although some Valpha and Vbeta families were more frequently expressed without evidence of clonality. Analysis of TCR in skin and synovial lesions of 3 patients showed identical CDR3 sequences, indicating that T cells bearing the same TCR are present at the 2 sites of chronic inflammation. These data suggest that common or similar crossreactive antigens present in the 2 locations are responsible for the expansion of the same TCR-bearing T cells possibly already activated by a superantigen. This supports the hypothesis that both polyclonal and oligoclonal lymphocyte activation contribute to the initiation and persistence of psoriatic arthritis.

Research paper thumbnail of Occupational allergic contact dermatitis from champignon and Polish mushroom. Contact Dermatitis

Research paper thumbnail of The presence of Parvovirus B19 VP and NS1 genes in the synovium is not correlated with rheumatoid arthritis

The Journal of Rheumatology

To amplify both NS1 and VP genes of Parvovirus B19 DNA in synovial membrane (SM) and serum obtain... more To amplify both NS1 and VP genes of Parvovirus B19 DNA in synovial membrane (SM) and serum obtained from patients with rheumatoid arthritis (RA) and to analyze whether the presence of viral DNA is correlated with synovitis. DNA obtained from 30 SM and 24 serum samples from RA patients was analyzed using single round-polymerase chain reaction (PCR) and nested PCR for both VP and NS1 genes of parvovirus B19. Twenty-four SM and serum samples from sex and age matched subjects with osteoarthritis (OA) or joint trauma served as controls. The first round PCR was negative for NS1 in RA samples. After nested PCR, NS1 was detected in the SM of 6/30 patients and of 10/24 controls and in the serum of 4/24 patients and controls. Nested PCR for the VP gene detected viral DNA in the SM of 7/30 patients with RA and of 7/24 of the controls and in the serum of 5/24 patients and of 2/24 controls. Altogether parvovirus DNA was found in the SM of 11/30 (36.6%) patients and of 12/24 (50%) controls and in the serum of 8/24 (33.3%) patients with RA and of 5/24 (20.8%) controls. Our results suggest that the amplification by nested PCR of both NS1 and VP genes is necessary to define the presence of viral DNA in tissue samples and confirm that the presence of parvovirus B19 DNA is similar in RA and control SM, suggesting that simple detection of viral DNA is not sufficient to confirm a link between the virus and RA.

Research paper thumbnail of Juvenile psoriatic arthritis and acquired sensorineural hearing loss in a teenager: is there an association?

Clinical and experimental rheumatology

Autoimmune inner ear disease is a cause of sensorineural hearing loss, first described in 1979 by... more Autoimmune inner ear disease is a cause of sensorineural hearing loss, first described in 1979 by McCabe. The occurrence during rheumatic diseases is already documented in adults, but to our knowledge, this evidence is still lacking in children. A 13-yr-old girl affected by juvenile psoriatic arthritis, treated with etanercept, developed a bilateral and asymmetric sensorineural deafness. The patient significantly improved after steroid administration. Once ruled out the principal causes of sensorineural hearing loss, we also considered the hypothesis of an anti-TNF side effect. However, the clinical presentation, the efficacy on steroid treatment and the presence of inner ear auto-antibodies prompt us to consider autoimmune-SNHL as the most plausible diagnosis. The young age of our patient seems to suggest a genetic susceptibility to autoimmunity and supports the concept of associated autoimmune diseases.

Research paper thumbnail of Induction of anti-DNA antibodies in non autoimmune mice by immunization with a DNA-DNAase I complex

Clinical and experimental rheumatology

Recent studies suggest that anti-DNA antibodies may arise from the immune response to a complex o... more Recent studies suggest that anti-DNA antibodies may arise from the immune response to a complex of DNA and a DNA-binding protein. One of the protein targets frequently recognized by anti-DNA antibodies is the enzyme DNAase I. To investigate the possible role of DNAase I in the induction of anti-DNA antibodies, we immunized mice with a complex of DNA and DNAase I. Mammalian double strand DNA was crosslinked with DNAase I by ultraviolet light (UV) treatment and emulsified in complete Freund's adjuvant. BALB/c mice were immunized at the base of the tail with the DNA-DNAase complex, boosted after 2 weeks with the immunogen in incomplete adjuvant and bled one week after the boost. Control mice received UV treated DNA in adjuvant. In one-third of the mice immunized with the DNA-DNAase complex, IgG anti-DNA antibodies were detectable in serum; the antibodies reacted with single and double strand DNA. No anti-DNA response was elicited by immunization with DNA alone. These data show that...

Research paper thumbnail of Molecular mimicry as a mechanism of induction of autoantibodies

Autoimmunity: Experimental Aspects, 1994

Research paper thumbnail of Autoimmunity and infection in common variable immunodeficiency (CVID)

Autoimmunity Reviews, 2016

Common variable immunodeficiency (CVID) is a heterogeneous group of diseases, characterized by pr... more Common variable immunodeficiency (CVID) is a heterogeneous group of diseases, characterized by primary hypogammaglobulinemia. B and T cell abnormalities have been described in CVID. Typical clinical features of CVID are recurrent airway infections; lymphoproliferative, autoinflammatory, or neoplastic disorders; and autoimmune diseases among which autoimmune thrombocytopenia (ITP) is the most common. The coexistence of immunodeficiency and autoimmunity appears paradoxical, since one represents a hypoimmune state and the other a hyperimmune state. Considering both innate and adaptive immune response abnormalities in CVID, it is easier to understand the mechanisms that lead to a breakdown of self-tolerance. CD21(low) B cells derive from mature B cells that have undergone chronic immune stimulation; they are increased in CVID patients. The expansion of CD21(low) B cells is also observed in certain autoimmune diseases. We have studied CD21(low) B cells in patients with CVID, CVID, and ITP and with ITP only. We observed a statistically significant increase in the CD21(low) population in the three pathological groups. Moreover, we found statistical differences between the two groups of CVID patients: patients with ITP had a higher percentage of CD21(low) cells. Our data suggest that CD21(low) cells are related to autoimmunity and may represent a link between infection and autoimmunity.

Research paper thumbnail of Chronic parvovirus B19 infection induces the production of antivirus antibodies with autoantigen binding properties

Immunol Lett, 1997

Poster presentations patients had a histoly of venous thrombosis and 11 female patients had a his... more Poster presentations patients had a histoly of venous thrombosis and 11 female patients had a history of soontaneous abortions.

Research paper thumbnail of Antibody associated with autoimmune pancreatitis and uses thereof

Research paper thumbnail of Serum DNase I, soluble Fas/FasL levels and cell surface Fas expression in patients with SLE : a possible explanation for the lack of efficacy of hrDNase I treatment

International Immunology, Jan 15, 2009

The objectives of the study are to evaluate DNase I serum levels and their correlation with solub... more The objectives of the study are to evaluate DNase I serum levels and their correlation with soluble Fas (sFas) and soluble Fas ligand (sFasL) and with cell surface Fas expression in patients with systemic lupus erythematosus (SLE), thus contributing to the dysregulated apoptosis typical of the disease. The methods include the following: Serum DNase I levels in patients and in controls were detected using the dot blot method and quantified by densitometry; sFas and sFasL were quantified using an ELISA system. Cell surface Fas expression was evaluated by FACS analysis. Apoptosis was studied by means of internucleosomal DNA degradation using a commercially available kit. The results are as follows: We found a significant difference in DNase I, sFas and sFasL serum levels between patients and controls. Levels of DNase I <7.79 ng ml 21 are more represented in patients with SLE. Active SLE is strongly associated with high sFas levels and detectable sFasL. DNase I does not correlate with sFas or sFasL, whereas it correlates with T cell surface Fas expression that is higher in patients with active SLE than in healthy controls. Finally, administration of exogenous human recombinant DNase (hrDNase) I to freshly isolated T cells up-regulates cell surface Fas expression and induces increased susceptibility to Fas-mediated apoptosis. In conclusion, our findings confirm that DNase I is low in SLE and suggest that it may play a role in apoptosis in SLE by regulating the surface expression of the cell death molecule Fas. This role may contribute to explain the inefficacy of hrDNase I in SLE, a treatment proposed for the ability of DNase I to remove DNA from auto-antigenic nucleoprotein complexes.

Research paper thumbnail of Alleli HLA-DRB1 e artrite reumatoide nel nord Italia: assenza di correlazione con la gravità delta malattia e con manifestazioni extra-articolari

Recenti Progressi in Medicina, 2005

Riassunto. Abbiamo studiato la frequenza degli alleli HLA-DRB1 in 101 pazienti affetti da artrite... more Riassunto. Abbiamo studiato la frequenza degli alleli HLA-DRB1 in 101 pazienti affetti da artrite reumatoide (AR) e in 229 soggetti sani con il metodo della reazione a catena della polimerasi e ibridizzazione oligonucleotide-specifica. Abbiamo osservato una ...

Research paper thumbnail of The role of peptide libraries in the identification of novel autoantigen targets in autoimmune diseases

Discovery Medicine, Mar 1, 2010

Identification of pathogenetically relevant autoantigen targets is a major goal in the study of a... more Identification of pathogenetically relevant autoantigen targets is a major goal in the study of autoimmune diseases. Indeed it may allow the development of new specific diagnostic tools and facilitate the understanding of the pathogenesis of a disease in order to individualize possible novel treatments. The random peptide library is a molecular biology method that consists of the display of random peptides on live microorganisms. The screening of the library with pooled immunoglobulins obtained from patients affected by an autoimmune disease may lead to the identification of novel autoantigens and of antibodies that are able to bind such antigens with high affinity. Testing patients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; sera for the presence of these antibodies may be helpful in the diagnosis of the disease. Moreover such antibodies can be investigated for their functional activity and therefore provide new insights into the pathogenesis of the disease.

Research paper thumbnail of Plant-Derived Chimeric Virus Particles for the Diagnosis of Primary Sjögren Syndrome

Frontiers in plant science, 2015

Plants are ideal for the production of protein-based nanomaterials because they synthesize and as... more Plants are ideal for the production of protein-based nanomaterials because they synthesize and assemble complex multimeric proteins that cannot be expressed efficiently using other platforms. Plant viruses can be thought of as self-replicating proteinaceous nanomaterials generally stable and easily produced in high titers. We used Potato virus X (PVX), chimeric virus particles, and Cowpea mosaic virus, empty virus-like particles to display a linear peptide (lipo) derived from human lipocalin, which is immunodominant in Sjögren's syndrome (SjS) and is thus recognized by autoantibodies in SjS patient serum. These virus-derived nanoparticles were thus used to develop a diagnostic assay for SjS based on a direct enzyme linked immunosorbent assay format. We found that PVX-lipo formulations were more sensitive than the chemically synthesized immunodominant peptide and equally specific when used to distinguish between healthy individuals and SjS patients. Our novel assay therefore allo...

Research paper thumbnail of Dextran-specific IgG response in hypersensitivity reactions to measles-mumps-rubella vaccine. Authors' reply

The Journal of Allergy and Clinical Immunology, Jan 12, 2008

Research paper thumbnail of Gene Expression Profiling in Peripheral Blood Mononuclear Cells of Patients with Common Variable Immunodeficiency: Modulation of Adaptive Immune Response following Intravenous Immunoglobulin Therapy

Plos One, May 15, 2014

Background: Regular intravenous immunoglobulin treatment is used to replace antibody deficiency i... more Background: Regular intravenous immunoglobulin treatment is used to replace antibody deficiency in primary immunodeficiency diseases; however the therapeutic effect seems to be related not only to antibody replacement but also to an active role in the modulation of the immune response. Common variable immunodeficiency is the most frequent primary immunodeficiency seen in clinical practice.

Research paper thumbnail of A method for retracing the putative antigen/antibody ratio of immune complexes in biological fluids

Clinical and experimental rheumatology

It is well known that immune complex (ICs) diseases are caused by a number of factors which influ... more It is well known that immune complex (ICs) diseases are caused by a number of factors which influence the localization, clearance and inflammatory potential of ICs. Several studies suggest that the Ag/Ab ratio is one of the most important of these. Previous studies have clarified that IC detection methods which differ, either in their recognition unit or in the phase used (solid or liquid), show a very poor correlation with each other. This study was developed in order to verify the hypothesis that different methods recognise different kinds of ICs on the basis of their Ag/Ab ratio. We used 3 homogeneous EIAs employing a probe complex enzyme--anti enzyme which competes with circulating ICs for the recognition unit (bovine conglutinin, C1q or monoclonal rheumatoid factor) to detect 10 unrelated in vitro-made ICs at different relative Ag/Ab concentrations (from 8 x Ag excess to 8 x Ab excess). We demonstrated that the 3 recognition units recognised the ICs principally on the basis of their Ag/Ab ratio. These results were then used to set up a mathematical model capable of retracing the Ag/Ab ratio of the ICs present in unknown samples. This was employed to test a panel of sera from patients with systemic lupus erythematosus, essential mixed cryoglobulinemia and rheumatoid arthritis; we obtained very suggestive results but they require further prospective studies to understand the full significance of this parameter.

Research paper thumbnail of Human and murine anti-DNA antibodies induce the production of anti-idiotypic antibodies with autoantigen-binding properties (epibodies) through immune-network interactions

The Journal of Immunology

To examine the potential role of immune-network interactions in the production of lupus autoantib... more To examine the potential role of immune-network interactions in the production of lupus autoantibodies, normal NZW rabbit antibody responses were analyzed after immunization with one of the following Ig preparations: human lupus serum anti-dsDNA antibodies, human lupus serum anti-ssDNA antibodies, a mixture of human lupus serum anti-dsDNA and anti-ssDNA antibodies, the MRL-lpr/lpr anti-dsDNA mAb H241, and the MRL-lpr/lpr anti-ssDNA mAb H130. Four of five rabbits produced Ig typical of lupus autoantibodies: individual rabbit Ig cross-reacted with multiple autoantigens including nucleic acids, cardiolipin, SmRNP, glomerular extract, laminin, and exogenous Ag. Rabbit anti-Id against human anti-dsDNA antibodies were highly specific for dsDNA. Notably, in each serum the autoantibody activity was confined to the anti-Id Ig fraction. A similar spontaneously occurring Id-anti-Id interaction was also found between anti-ssDNA and anti-dsDNA antibodies isolated from an individual lupus patient. These results indicate that lupus autoantibodies which share Ag binding properties with pathogenic Ig, including both cross-reactive and anti-dsDNA antibodies, can induce the production of Ig with similar autoantigen binding properties through immune-network interactions. This phenomenon, if unregulated, could lead to the amplification of pathogenic autoantibody production in individuals with systemic lupus.

Research paper thumbnail of An immunoglobulin light chain from a lupus-prone mouse induces autoantibodies in normal mice

Journal of Experimental Medicine

Research paper thumbnail of Immune complex behaviour during prolonged plasma exchange in essential mixed cryoglobulinemia and systemic lupus erythematosus

The International journal of artificial organs

A number of immunological parameters were measured in 9 patients with essential mixed cryoglobuli... more A number of immunological parameters were measured in 9 patients with essential mixed cryoglobulinemia and 12 patients with systemic lupus erythematosus undergoing plasma exchange alone or without cytotoxic drugs. Only cryocrit significantly decreased in the majority of patients with essential mixed cryoglobulinemia. In contrast, immune complex levels, measured in two different ways, did not change on the whole, although variable and unpredictable changes were often present in individual patients. Thus, these data do not support the view that the mechanism(s) of action of plasma exchange in these diseases is only due to the quantitative removal of circulating immune complexes, and qualitative changes in the immune complex moiety may also occur.

Research paper thumbnail of Calcinosis universalis in systemic sclerosis with limited scleroderma

Clinical and experimental rheumatology

Research paper thumbnail of The T cell receptor repertoire in psoriatic synovitis is restricted and T lymphocytes expressing the same TCR are present in joint and skin lesions

The Journal of Rheumatology

To investigate the T cell receptor (TCR) repertoire in psoriatic synovitis and to determine wheth... more To investigate the T cell receptor (TCR) repertoire in psoriatic synovitis and to determine whether T lymphocytes in joint and skin lesions show the same Vbeta CDR3 region. The expression of Valpha and Vbeta families was evaluated by reverse transcriptase-polymerase chain reaction. The CDR3 region of some Vbeta families was analyzed by cloning and sequencing. We found a diverse variable beta chain usage within psoriatic synovial fluid of 11 patients although some Valpha and Vbeta families were more frequently expressed without evidence of clonality. Analysis of TCR in skin and synovial lesions of 3 patients showed identical CDR3 sequences, indicating that T cells bearing the same TCR are present at the 2 sites of chronic inflammation. These data suggest that common or similar crossreactive antigens present in the 2 locations are responsible for the expansion of the same TCR-bearing T cells possibly already activated by a superantigen. This supports the hypothesis that both polyclonal and oligoclonal lymphocyte activation contribute to the initiation and persistence of psoriatic arthritis.

Research paper thumbnail of Occupational allergic contact dermatitis from champignon and Polish mushroom. Contact Dermatitis

Research paper thumbnail of The presence of Parvovirus B19 VP and NS1 genes in the synovium is not correlated with rheumatoid arthritis

The Journal of Rheumatology

To amplify both NS1 and VP genes of Parvovirus B19 DNA in synovial membrane (SM) and serum obtain... more To amplify both NS1 and VP genes of Parvovirus B19 DNA in synovial membrane (SM) and serum obtained from patients with rheumatoid arthritis (RA) and to analyze whether the presence of viral DNA is correlated with synovitis. DNA obtained from 30 SM and 24 serum samples from RA patients was analyzed using single round-polymerase chain reaction (PCR) and nested PCR for both VP and NS1 genes of parvovirus B19. Twenty-four SM and serum samples from sex and age matched subjects with osteoarthritis (OA) or joint trauma served as controls. The first round PCR was negative for NS1 in RA samples. After nested PCR, NS1 was detected in the SM of 6/30 patients and of 10/24 controls and in the serum of 4/24 patients and controls. Nested PCR for the VP gene detected viral DNA in the SM of 7/30 patients with RA and of 7/24 of the controls and in the serum of 5/24 patients and of 2/24 controls. Altogether parvovirus DNA was found in the SM of 11/30 (36.6%) patients and of 12/24 (50%) controls and in the serum of 8/24 (33.3%) patients with RA and of 5/24 (20.8%) controls. Our results suggest that the amplification by nested PCR of both NS1 and VP genes is necessary to define the presence of viral DNA in tissue samples and confirm that the presence of parvovirus B19 DNA is similar in RA and control SM, suggesting that simple detection of viral DNA is not sufficient to confirm a link between the virus and RA.

Research paper thumbnail of Juvenile psoriatic arthritis and acquired sensorineural hearing loss in a teenager: is there an association?

Clinical and experimental rheumatology

Autoimmune inner ear disease is a cause of sensorineural hearing loss, first described in 1979 by... more Autoimmune inner ear disease is a cause of sensorineural hearing loss, first described in 1979 by McCabe. The occurrence during rheumatic diseases is already documented in adults, but to our knowledge, this evidence is still lacking in children. A 13-yr-old girl affected by juvenile psoriatic arthritis, treated with etanercept, developed a bilateral and asymmetric sensorineural deafness. The patient significantly improved after steroid administration. Once ruled out the principal causes of sensorineural hearing loss, we also considered the hypothesis of an anti-TNF side effect. However, the clinical presentation, the efficacy on steroid treatment and the presence of inner ear auto-antibodies prompt us to consider autoimmune-SNHL as the most plausible diagnosis. The young age of our patient seems to suggest a genetic susceptibility to autoimmunity and supports the concept of associated autoimmune diseases.

Research paper thumbnail of Induction of anti-DNA antibodies in non autoimmune mice by immunization with a DNA-DNAase I complex

Clinical and experimental rheumatology

Recent studies suggest that anti-DNA antibodies may arise from the immune response to a complex o... more Recent studies suggest that anti-DNA antibodies may arise from the immune response to a complex of DNA and a DNA-binding protein. One of the protein targets frequently recognized by anti-DNA antibodies is the enzyme DNAase I. To investigate the possible role of DNAase I in the induction of anti-DNA antibodies, we immunized mice with a complex of DNA and DNAase I. Mammalian double strand DNA was crosslinked with DNAase I by ultraviolet light (UV) treatment and emulsified in complete Freund's adjuvant. BALB/c mice were immunized at the base of the tail with the DNA-DNAase complex, boosted after 2 weeks with the immunogen in incomplete adjuvant and bled one week after the boost. Control mice received UV treated DNA in adjuvant. In one-third of the mice immunized with the DNA-DNAase complex, IgG anti-DNA antibodies were detectable in serum; the antibodies reacted with single and double strand DNA. No anti-DNA response was elicited by immunization with DNA alone. These data show that...