Elisa Tinazzi

Human parvovirus B19 infection and autoimmunity

Human parvovirus B19 infection is responsible for a wide range of human diseases ranging from mild erythema infectiosum in immunocompetent children to fetal loss in primary infected pregnant women and aplastic anemia or lethal cytopenias in adult immunocompromised patients. Since persistent viral infection is responsible for an autoimmune response and clinical symptoms can mimic autoimmune inflammatory disorders, parvovirus B19 is the object of intense efforts to clarify whether it is also able to trigger autoimmune diseases. Indeed the virus has been implicated as the causative or the precipitating agent of several autoimmune disorders including rheumatoid arthritis, systemic lupus, antiphospholipid syndrome, systemic sclerosis and vasculitides. Molecular mimicry between host and viral proteins seems to be the main mechanism involved in the induction of autoimmunity. By means of a random peptide library approach, we have identified a peptide that shares homology with parvovirus VP1 protein and with human cytokeratin. Moreover the VP peptide shares similarity with the transcription factor GATA1 that plays an essential role in megakaryopoiesis and in erythropoiesis. These new data sustain the role played by molecular mimicry in the induction of cross-reactive (auto)antibodies by parvovirus B19 infection.

Clinical, biochemical and molecular findings in a series of families with hereditary hyperferritinaemia-cataract syndrome.

Hereditary hyperferritinaemia–cataract syndrome (HHCS) is an autosomal dominant disease caused by mutations in the iron responsive element (IRE) of the l‐ferritin gene. Despite the elucidation of the genetic basis, the overall clinical spectrum of HHCS has been less well studied as, to date, only individual case reports have been described. Therefore, we studied a total of 62 patients in 14 unrelated families, with nine different mutations. No relevant symptoms other than visual impairment were found to be associated with the syndrome. A marked phenotypic variability was observed, particularly with regard to ocular involvement (i.e. age range at which cataract was diagnosed in 16 subjects with the C39T: 6–40 years). Similarly, serum ferritin levels varied substantially also within subjects sharing the same mutation (i.e. range for the A40G: 700–2412 µg/l). We followed an HHCS newborn in whom well‐defined lens opacities were not detectable either at birth or at 1 year. The lens ferritin content was analysed in two subjects who underwent cataract surgery at different ages, with different cataract morphology. Values were similar and about 1500‐fold higher than in controls. These observations suggest that: (i) in HHCS the cataract is not necessarily congenital; (ii) in addition to the IRE genotype, other genetic or environmental factors may modulate the phenotype, especially the severity of the cataract.

In chronic idiopathic urticaria autoantibodies against FcεRII/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 α subunit of the high‐affinity IgE receptor or the IgE molecule in nearly half of the patients.

Reactive arthritis following BCG immunotherapy for urinary bladder carcinoma: a systematic review

Intravesical instillation of Bacillus Calmette-Guerin (BCG) is used with efficacy and safety in the treatment of patients with intermediate and high-risk superficial bladder carcinoma. Arthralgia and/or arthritis is one of the rare severe complications following intravesical BCG immunotherapy. We searched MEDLINE in order to analyze the frequency of this clinical complication, its pathogenesis and outcome. The electronic search was conducted using the following key words: “BCG immunotherapy” and “Arthritis, arthralgias and BCG immunotherapy”. At the end of a process of abstract analysis, 48 papers were included in the systematic review. All the selected papers, except one that was a clinical review, described at least one case of arthritis after BCG therapy. The BCG immunotherapy resulted to be safe and efficacious in the treatment of bladder cancer; the development of reactive arthritis is rare and can evolve in a chronic process. The review of the literature highlighted that reactive arthritis following BCG intravesical instillation is a complication usually well controlled with the discontinuation of the immunotherapy and nonsteroidal anti-inflammatory drugs (NSAIDs) treatment. Only a small portion of patients with a particular genetic background will develop a chronic process.

A1298C methylenetetrahydrofolate reductase mutation and coronary artery disease: relationships with C677T polymorphism and homocysteine/folate metabolism.

Abstract 5, 10-Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme in homocysteine/methionine metabolism. The most-studied C677T polymorphism in the MTHFR gene results in a thermolabile variant with reduced activity, and is associated with increased levels of total plasma homocysteine, a risk factor for coronary artery disease. A new mutation in the MTHFR gene (A1298C) has also been reported to lower enzyme activity. Whether A1298C is a risk factor for coronary artery disease, separately or in combination with C677T, and/or relative to total plasma homocysteine and folate status, is unclear to date. We evaluated this hypothesis in 470 angiographically characterized subjects, 302 with coronary artery disease, and 168 with normal coronary arteries. The frequency of the 1298C allele was 0.33 and that of combined heterozygosity 0.315. No difference was found in the frequency of the genotypes or when analyzed for combined heterozygosity between patients with coronary artery disease and normals. Independent of folate status, the 1298C allele was not associated with increased total plasma homocysteine. No additional effect of A1298C on total plasma homocysteine was observed in 148 combined heterozygotes compared with 98 heterozygotes for the C677T alone. These findings do not support a major role for the A1298C mutation in homocysteine metabolism and emphasize the hypothesis that MTHFR genotypes may interfere with coronary artery disease risk only when an unbalanced nutritional status leads to raised total plasma homocysteine levels.

Endothelial Cells' Activation and Apoptosis Induced by a Subset of Antibodies against Human Cytomegalovirus: Relevance to the Pathogenesis of Atherosclerosis

Background Human cytomegalovirus (hCMV) is involved in the pathogenesis of atherosclerosis. We have previously shown in patients with atherosclerosis that antibodies directed against the hCMV-derived proteins US28 and UL122 are able to induce endothelial cell damage and apoptosis of non-stressed endothelial cells through cross-rection with normally expressed surface molecules. Our aim was to dissect the molecular basis of such interaction and to investigate mechanisms linking innate immunity to atherosclerosis. Methodology/Principal Findings We analysed the gene expression profiles in endothelial cells stimulated with antibodies affinity-purified against either the UL122 or the US28 peptides using the microarray technology. Microarray results were validated by quantitative PCR and by detection of proteins in the medium. Supernatant of endothelial cells incubated with antibodies was analysed also for the presence of Heat Shock Protein (HSP)60 and was used to assess stimulation of Toll-Like Receptor-4 (TLR4). Antibodies against UL122 and US28 induced the expression of genes encoding for adhesion molecules, chemokines, growth factors and molecules involved in the apoptotis process together with other genes known to be involved in the initiation and progression of the atherosclerotic process. HSP60 was released in the medium of cells incubated with anti-US28 antibodies and was able to engage TLR4. Conclusions/Significance Antibodies directed against hCMV modulate the expression of genes coding for molecules involved in activation and apoptosis of endothelial cells, processes known to play a pivotal role in the pathogenesis of atherosclerosis. Moreover, endothelial cells exposed to such antibodies express HSP60 on the cell surface and release HSP60 in the medium able to activate TLR4. These data confirm that antibodies directed against hCMV-derived proteins US28 and UL122 purified from patients with coronary artery disease induce endothelial cell damage and support the hypothesis that hCMV infection may play a crucial role in mediating the atherosclerotic process.

Mature CD10+ and immature CD10- neutrophils present in G-CSF-treated donors display opposite effects on T cells

The identification of discrete neutrophil populations, as well as the characterization of their immunoregulatory properties, is an emerging topic under extensive investigation. In such regard, the presence of circulating CD66b+ neutrophil populations, exerting either immunosuppressive or proinflammatory functions, has been described in several acute and chronic inflammatory conditions. However, due to the lack of specific markers, the precise phenotype and maturation status of these neutrophil populations remain unclear. Herein, we report that CD10, also known as common acute lymphoblastic leukemia antigen, neutral endopeptidase, or enkephalinase, can be used as a marker that, within heterogeneous populations of circulating CD66b+ neutrophils present in inflammatory conditions, clearly distinguishes the mature from the immature ones. Accordingly, we observed that the previously described immunosuppressive neutrophil population that appears in the circulation of granulocyte colony-stimulating factor (G-CSF)-treated donors (GDs) consists of mature CD66b+CD10+ neutrophils displaying an activated phenotype. These neutrophils inhibit proliferation and interferon γ (IFNγ) production by T cells via a CD18-mediated contact-dependent arginase 1 release. By contrast, we found that immature CD66b+CD10- neutrophils, also present in GDs, display an immature morphology, promote T-cell survival, and enhance proliferation and IFNγ production by T cells. Altogether, our findings uncover that in GDs, circulating mature and immature neutrophils, distinguished by their differential CD10 expression, exert opposite immunoregulatory properties. Therefore, CD10 might be used as a phenotypic marker discriminating mature neutrophils from immature neutrophil populations present in patients with acute or chronic inflammatory conditions, as well as facilitating their isolation, to better define their specific immunoregulatory properties.

International consensus: What else can we do to improve diagnosis and therapeutic strategies in patients affected by autoimmune rheumatic diseases (rheumatoid arthritis, spondyloarthritides, systemic sclerosis, systemic lupus erythematosus, antiphospholipid syndrome and Sjogren's syndrome)?: The unmet needs and the clinical grey zone in autoimmune disease management

Autoimmune diseases are a complex set of diseases characterized by immune system activation and, although many progresses have been done in the last 15years, several unmet needs in the management of these patients may be still identified. Recently, a panel of international Experts, divided in different working groups according to their clinical and scientific expertise, were asked to identify, debate and formulate a list of key unmet needs within the field of rheumatology, serving as a roadmap for research as well as support for clinicians. After a systematic review of the literature, the results and the discussions from each working group were summarised in different statements. Due to the differences among the diseases and their heterogeneity, a large number of statements was produced and voted by the Experts to reach a consensus in a plenary session. At all the steps of this process, including the initial discussions by the steering committee, the identification of the unmet needs, the expansion of the working group and finally the development of statements, a large agreement was attained. This work confirmed that several unmet needs may be identified and despite the development of new therapeutic strategies as well as a better understanding of the effects of existing therapies, many open questions still remain in this field, suggesting a research agenda for the future and specific clinical suggestions which may allow physicians to better manage those clinical conditions still lacking of scientific clarity.

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

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(-1) 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.

Schnitzler's syndrome treated successfully with intravenous pulse cyclophosphamide

Schnitzlers syndrome is a rare clinical condition characterized by chronic urticaria, intermittent fever, bone pain, arthralgia or arthritis, and monoclonal immunoglobulin M (IgM) gammopathy. Here we describe the case of a 48‐year‐old Italian female with a long history of arthralgia, leucocytosis, spiking fever, and chronic urticaria with severe pruritus. The IgM‐κ monoclonal component in the serum and bone densification on conventional X‐ray with hyperfixation on bone technetium scanning at the distal part of the femurs and at the proximal part of the tibias were detected 4 years after the onset of the symptoms. After many ineffective treatments, the use of pulse cyclophosphamide (CPX) resulted in complete remission of the disease that is still lasting after a 2‐year follow‐up.