Persistence of bDMARD therapy in Rheumatoid Arthritis after first-line TNF-inhibitor failure: the RECORD study of the Italian Society for Rheumatology.

OBJECTIVE: The optimal choice of a second biological disease-modifying anti-rheumatic drug (bDMARD) after failure with first line tumour necrosis factor inhibitor (TNFi) represents a critical therapeutic challenge. This study aims to evaluate the persistence with treatment using second line bDMARDs with different mechanisms of action in rheumatoid arthritis (RA) patients with inadequate response to first line TNFi. METHOD: A retrospective cohort study on administrative healthcare databases was conducted. We analysed the relationship between different bDMARDs and persistence with treatment in RA patients who started second line bDMARD therapy according to two different strategies: cycling (second TNFi) or switching [change in mechanism of action: abatacept (ABA), tocilizumab (TCZ), and rituximab (RTX)] with or without concomitant conventional synthetic (cs) DMARDs. RESULTS: The cohort comprised 1434 patients. The mean age was 53.8 years and 1142 (79.6%) were women. Among second line bDMARDs, 969 patients (67.6%) started TNFi, 204 (14.2%) ABA, 145 (10.1%) RTX, and 116 (8.1%) TCZ. A bDMARD was prescribed as monotherapy in 359 patients (25.0%). The switching strategy showed a lower overall discontinuation rate [hazard ratio (HR) 0.72], while switching compared to cycling showed significantly better survival for ABA (HR 0.61) and RTX (HR 0.76), but no significant difference for TCZ (HR 0.82). A lower impact of better drug survival in the switching strategy occurred in patients with concurrent methotrexate. CONCLUSIONS: Among RA patients failing a first TNFi, switching is associated with marginally better persistence, in particular for ABA and RTX, with only marginal differences in patients on concurrent csDMARDs.

The Italian Society of Rheumatology clinical practice guidelines for the management of large vessel vasculitis.

OBJECTIVE: Since of the last publication of last recommendations on primary large-vessel vasculitis (LVV) endorsed by the Italian Society of Rheumatology (SIR) in 2012, new evidence emerged regarding the diagnosis and the treatment with conventional and biologic immunosuppressive drugs. The associated potential change of clinical care supported the need to update the original recommendations. METHODS: Using the grading of recommendations assessment, development and evaluation (GRADE)-ADOLOPMENT framework, a systematic literature review was performed to update the evidence supporting the European Alliance of Associations for Rheumatology (EULAR) guidelines on LVV as reference. A multidisciplinary panel of 12 expert clinicians, a trained nurse, and a patients' representative discussed the recommendation in cooperation with an Evidence Review Team. Sixty-one stakeholders were consulted to externally review and rate the recommendations. RESULTS: Twelve recommendations were formulated. A suspected diagnosis of LVV should be confirmed by imaging or histology. In active GCA or TAK, the prompt commencement of high dose of oral glucocorticoids (40-60 mg prednisone-equivalent per day) is strongly recommended to induce clinical remission. In selected patients with GCA (e.g., refractory or relapsing disease or patients at risk of glucocorticoid related adverse effects) the use of an adjunctive therapy (tocilizumab or methotrexate) is recommended. In all patients diagnosed with TAK, adjunctive therapies, such as conventional synthetic or biological immunosuppressants, should be given in combination with glucocorticoids. CONCLUSIONS: The new set of SIR recommendations was formulated in order to provide a guidance on both diagnosis and treatment of patients suspected of or with a definite diagnosis of LVV.

Role of comorbidities on therapeutic persistence of biological agents in rheumatoid arthritis: results from the RECord-linkage On Rheumatic Disease study on administrative healthcare databases.

Objectives: This study aimed to evaluate the impact of different comorbidities on thereflecting its safety profile persistence of biological disease-modifying anti-rheumatic drugs (bDMARDs) in rheumatoid arthritis (RA), taking advantage of a retrospective analysis of administrative healthcare databases (AHDs).Method: A retrospective observational study was conducted on AHDs of the Lombardy region, Italy (2004-2013). Among RA patients treated with bDMARDs, drug survival was estimated using Cox proportional hazard models [hazard ratio (HR), 95% confidence interval (CI)], crude and adjusted for prespecified confounders (gender, age, disease duration, concomitant use of non-steroidal anti-inflammatory drugs, glucocorticoids, conventional DMARDs, specific bDMARDs), in first-line and subsequent lines of treatment. The role of comorbidities in administration of specific bDMARDs was analysed through multinomial logistic models.Results: The study included 4657 RA patients. In the first-line treatment strategy, the Charlson Comorbidity Index (CCI) (RA excluded) was significantly associated with an increased rate of bDMARD failure (CCI = 1: HR 1.28, 95% CI 1.13-1.46; CCI ≥ 2: HR 1.26, 95% CI 1.03-1.53). Among selected comorbidities, chronic obstructive pulmonary disease (HR 1.38, 95% CI 1.01-1.91), diabetes (HR 1.18, 95% CI 1.01-1.37), and previous-year bacterial infections (HR 1.18, 95% CI 1.07-1.30) were slightly associated with risk of bDMARD failure, while acute myocardial infarction (HR 1.30, 95% CI 0.97-1.75), mild liver disease (HR 1.21, 95% CI 0.91-1.60), and solid tumours (HR 1.19, 95% CI 0.93-1.53) were not. In the following treatment lines, neoplasms were associated with reduced risk of failure (HR 0.64, 95% CI 0.41-0.99). Multiple comorbidities were associated with first-line abatacept and rituximab administration.Conclusions: Comorbidities affect treatment decisions in RA and influence bDMARD failure, and should be considered when analysing the persistence of biological therapy.

The Italian Society for Rheumatology recommendations for the management of axial spondyloarthritis.

Over the last few years, the landscape of treatments for axial spondyloarthritis (SpA) has been rapidly evolving, urging international scientific societies to draft or update existing clinical practice guidelines (CPGs) on the management of axial SpA. The Italian Society for Rheumatology (SIR) committed to provide revised and adapted evidence- and expert-based recommendations for the management of patients with axial SpA in Italy. A systematic approach to the adaptation of existing CPGs - the ADAPTE methodology - was adopted to obtain updated recommendations suitable for the Italian context. A systematic literature search was performed in Medline and Embase databases to find international CPGs and consensus statements with recommendations for the management of axial SpA published in the previous five years. A working group composed of rheumatologists with proven experience in the management of axial SpA and methodologists identified the key research questions which guided study selection and data extraction. Guideline quality was assessed using the Appraisal of Guidelines Research and Evaluation (AGREE) II tool. The Italian recommendations were developed by endorsing or adapting and rewording some existing recommendations. The draft of the recommendations was sent to a multidisciplinary group of external reviewers for comment and rating. Six original CPGs were selected and used to create this SIR CPG, which includes a final set of 14 recommendations covering the management of patients with axial SpA across the following domains: assessment, pharmacological and non-pharmacological treatment, and follow-up. The dissemination and implementation of these SIR recommendations are expected to support an evidencebased clinical approach to the management of patients with axial SpA in Italy.

Providing updated guidelines for the management of rheumatic diseases in Italy with the ADAPTE methodology: a project by the Italian Society for Rheumatology.

Not available.

Early Lupus Project: one-year follow-up of an Italian cohort of patients with systemic lupus erythematosus of recent onset.

Objective To describe the clinical and serological features of a prospectively followed cohort of early diagnosed systemic lupus erythematosus (SLE) patients during a one-year follow-up period. Methods SLE patients with disease duration less than 12 months were consecutively enrolled in a multicentre, prospective study. At study entry and then every 6 months, a large panel of data was recorded. Results Of 260 patients enrolled, 185 had at least 12 months of follow-up; of these, 84.3% were female, 92.4% were Caucasians. Mean diagnostic delay was about 20 months; higher values of European Consensus Lupus Activity Measurement (ECLAM) and of organs/systems involved were both associated with shorter diagnostic delay. Clinical and serological parameters improved after study entry. However, patients' quality of life deteriorated and cardiovascular risk factors significantly increased. About one-third of patients with active disease at study entry went into remission (ECLAM = 0). Negative predictors for remission were: oral ulcers, arthritis, low C4, anti-SSB (Ro) antibodies and therapy with mycophenolate. There was a widespread use of glucocorticoids both at baseline and during follow-up. Conclusion Clinical symptoms and serological parameters improve during the first period after diagnosis. However, patients' quality of life deteriorates. The widespread use of glucocorticoids is probably the reason for the early significant increase of some cardiovascular risk factors.

Network-guided modeling allows tumor-type independent prediction of sensitivity to all-trans-retinoic acid.

Background: All-trans-retinoic acid (ATRA) is a differentiating agent used in the treatment of acute-promyelocytic-leukemia (APL) and it is under-exploited in other malignancies despite its low systemic toxicity. A rational/personalized use of ATRA requires the development of predictive tools allowing identification of sensitive cancer types and responsive individuals. Materials and methods: RNA-sequencing data for 10 080 patients and 33 different tumor types were derived from the TCGA and Leucegene datasets and completely re-processed. The study was carried out using machine learning methods and network analysis. Results: We profiled a large panel of breast-cancer cell-lines for in vitro sensitivity to ATRA and exploited the associated basal gene-expression data to initially generate a model predicting ATRA-sensitivity in this disease. Starting from these results and using a network-guided approach, we developed a generalized model (ATRA-21) whose validity extends to tumor types other than breast cancer. ATRA-21 predictions correlate with experimentally determined sensitivity in a large panel of cell-lines representative of numerous tumor types. In patients, ATRA-21 correctly identifies APL as the most sensitive acute-myelogenous-leukemia subtype and indicates that uveal-melanoma and low-grade glioma are top-ranking diseases as for average predicted responsiveness to ATRA. There is a consistent number of tumor types for which higher ATRA-21 predictions are associated with better outcomes. Conclusions: In summary, we generated a tumor-type independent ATRA-sensitivity predictor which consists of a restricted number of genes and has the potential to be applied in the clinics. Identification of the tumor types that are likely to be generally sensitive to the action of ATRA paves the way to the design of clinical studies in the context of these diseases. In addition, ATRA-21 may represent an important diagnostic tool for the selection of individual patients who may benefit from ATRA-based therapeutic strategies also in tumors characterized by lower average sensitivity.

Seroepidemiology of HEV and HAV in two populations with different socio-economic levels and hygienic/sanitary conditions.

The epidemiological scenarios of hepatitis E virus (HEV) and hepatitis A virus (HAV) infections have changed in the last few decades, but precise epidemiological data on the prevalence of anti-HEV and anti-HAV, alone or in combination, in the general population are scanty. We investigated HEV and HAV seroprevalence comparing two population samples living in Northern (Abbiategrasso, Milan) and Southern Italy (Cittanova, Reggio Calabria), the latter being characterized by a poorer socio-economic level and hygienic/sanitary conditions. Based on census records, we randomly enrolled and tested 3,365 subjects (Abbiategrasso, n = 2,489; Cittanova, n = 876) aged 18-75 years for anti-HAV and anti-HEV. Anti-HAV (71.3 % vs 52.5 %) and anti-HEV (17.8 % vs 9.0 %) prevalence rates were higher in Southern Italy (both p < 0.001). Most anti-HEV-positive subjects also had anti-HAV. Subjects testing positive for anti-HAV, alone or with anti-HEV, were older (p < 0.001 in both populations) and showed a trend toward declining prevalence in the youngest birth cohorts. The prevalence of subjects with a positive result for anti-HEV alone did not change in birth cohorts in the two towns. Detection of anti-HEV was independently associated with anti-HAV, town, birth cohort, and education level in multivariate analysis. Low socio-economic level and hygienic/sanitary conditions are associated with high HAV and HEV seroprevalence rates in Italy. Recent improvements, especially in the South, have led to a declining prevalence of anti-HAV, alone or with anti-HEV. Seroprevalence of HEV alone is uniformly low and does not change in birth cohorts born between 1938 and 1993.

Lessons learnt over two decades of vaccination against hepatitis B in Italy.

This article reviews topics covered and discussed at the Meeting: "Vaccini e vaccinazioni. Migliorare l'oggi e preparare il domani", held in Genoa, Italy, on 12 September 2014. Data presented at the meeting, clearly showed that: 1) hepatitis B vaccination can confer long-term protection and there is no need for booster in immunocompetent vaccinees; 2) vaccination is highly effective in protecting population from clinical acute or chronic HBV infections, including hepatocellular carcinoma; 3) children vaccinated as infants with hexavalent vaccines maintain immunological memory 5 years after priming, but further studies are needed to assess whether immunity persists during the adolescence and adulthood when risk of exposure to HBV becomes higher; 4) the emergence of vaccine-escape mutants and Pol-gene mutants during antiviral therapy - which can result in changes in the S-gene - is of some concern, but at present there is no evidence that such mutants may pose a threat to the established programs of vaccination.

Hepatitis E: a puzzling double-faced disease.

Viral hepatitis type E is highly endemic in many developing countries, where large water-borne epidemics caused by viral genotype 1 and - to a lesser degree - by genotype 2 cyclically occur, resulting in high morbidity and mortality, especially among pregnant women. In developed countries, the disease is usually diagnosed in travelers coming back from endemic countries, but an increasing number of sporadic locally acquired hepatitis cases caused by genotype 3 and 4 have recently been reported. The wide-spread distribution of HEV3 and HEV4 in domestic pigs, wild boars, deer, as well as in other mammals, suggests that infections caused by these genotypes may have a zoonotic source. HEV3 infection can evolve to chronic infection in immunosuppressed patients; in addition, it may be associated with neurological disorders and extrahepatic manifestations. Two recently developed recombinant vaccines have proved to be safe and effective. One of such vaccines has recently been licensed for use in China.

The state of hepatitis B and C in Europe: report from the hepatitis B and C summit conference*.

Worldwide, the hepatitis B virus (HBV) and the hepatitis C virus (HCV) cause, respectively, 600,000 and 350,000 deaths each year. Viral hepatitis is the leading cause of cirrhosis and liver cancer, which in turn ranks as the third cause of cancer death worldwide. Within the WHO European region, approximately 14 million people are chronically infected with HBV, and nine million people are chronically infected with HCV. Lack of reliable epidemiological data on HBV and HCV is one of the biggest hurdles to advancing policy. Risk groups such as migrants and injecting drug users (IDU) tend to be under-represented in existing prevalence studies; thus, targeted surveillance is urgently needed to correctly estimate the burden of HBV and HCV. The most effective means of prevention against HBV is vaccination, and most European Union (EU) countries have universal vaccination programmes. For both HBV and HCV, screening of individuals who present a high risk of contracting the virus is critical given the asymptomatic, and thereby silent, nature of disease. Screening of migrants and IDUs has been shown to be effective and potentially cost-effective. There have been significant advances in the treatment of HCV and HBV in recent years, but health care professionals remain poorly aware of treatment options. Greater professional training is needed on the management of hepatitis including the treatment of liver cancer to encourage adherence to guidelines and offer patients the best possible outcomes. Viral hepatitis knows no borders. EU Member States, guided by the EU, need to work in a concerted manner to implement lasting, effective policies and programmes and make tackling viral hepatitis a public health priority.

Long-lasting immunogenicity and safety of a 2009 pandemic influenza A(H1N1) MF59-adjuvanted vaccine when co-administered with a 2009-2010 seasonal influenza vaccine in young patients with type 1 diabetes mellitus.

AIMS: To evaluate the long-lasting immunogenicity and safety of a pandemic vaccine co-administered with a seasonal influenza vaccine in young subjects with Type 1 diabetes. METHODS: Eighty patients (mean age: 16.7 ± 5.5 years, disease duration: 10.2 ± 4.7 years) were randomly assigned to receive a single or a double dose (1 month apart) of MF59-adjuvanted influenza A(H1N1) vaccine, simultaneously with a single dose of a virosome-adjuvanted trivalent influenza vaccine for the 2009-2010 season. RESULTS: One month after immunization, the rate of seroconversion to 2009 pandemic A(H1N1) was 92.5% with an overall 100% proportion of vaccinees with protective antibody titres (≥ 1:40). No significant differences were observed between vaccinees who received the one-dose or the two-dose schedule. Seasonal vaccine induced a significant increase of both seroprotection rates and antibody levels. Local adverse events at the injection site of pandemic and seasonal vaccines were reported by 66.3% and 50% of subjects, respectively. Solicited systemic adverse events, mainly mild in intensity, were reported by 26.7% of vaccinees. No subjects had an influenza-like illness during the 6-month follow-up. CONCLUSIONS: One injection of 2009 pandemic influenza A(H1N1) MF59-adjuvanted vaccine is immunogenic and safe in young patients with Type 1 diabetes who are at increased risk of influenza morbidities. Pandemic vaccine can be safely co-administered with seasonal influenza vaccine.

Is avian influenza virus A(H5N1) a real threat to human health?

The A(H5N1) influenza remains a disease of birds with a significant species barrier: in the presence of some tens million cases of infection in poultry--with a wide geographical spread--, only a few hundreds cases have occurred in humans. To date, human cases have been reported in 15 countries--mainly in Asia--and all were related to the onset of outbreaks in poultry. A peak of H5N1 human cases was recorded in 2006, then decreasing in subsequent years. Despite this trend, the H5N1 virus still represents a possible threat to human health, considering that more than half of human cases of H5N1 have been fatal. Moreover, despite the drop in the number of cases, the risk of a novel pandemic cannot be excluded, since H5N1 continues to circulate in poultry in countries with elevated human population density and where monitoring systems are not fully appropriate. In addition, there is a major global concern about the potential occurrence of a reassortment between the 2009 pandemic H1N1 and the highly pathogenic H5N1 influenza viruses following a co-infection in a susceptible host. Therefore, the implementation of appropriate surveillance and containment measures is crucial in order to minimize such risk. In conclusion, H5N1 avian influenza is still a rare disease in humans but its clinical severe outcome requires a careful monitoring of the virus's ability to evolve and to trigger a new pandemic.

Early co-circulation of different clades of influenza A/H1N1v pandemic virus in northern Italy.

INTRODUCTION: The spatial diffusion over time of pandemic influenza A/HINI virus (A/HIN1v) was surveyed in Northern Italy (nearly 10 million inhabitants)from April to December 2009, and the molecular characteristics of circulating viruses were analyzed to identify the appearance of drift variants. About 45% of analyzed samples were laboratory-confirmed cases of A/HINlv. Sporadic cases occurred until the middle of June 2009, then, case numbers began to increase delineating distinct epidemiological phases of viral circulation. METHODS: RNA was extracted using RNeasy Mini kit (QIAGEN GmbH, Germany). Virological diagnosis of A/HINlv infection was carried out by real-time RT-PCR assay. Sequence analysis of hemagglutinin (HA) gene was performed through a RT-PCR assay specific for a 995 bp fragment (nt. 64-1,058) in the HAl domain. The nucleotide sequences were obtained by automated DNA sequencing. The HAl sequences were aligned with other sequences collected from GenBank database by ClustalX software. The multiple sequence alignment was used to perform a basic phylogenetic analysis and a phylogenetic tree from HA sequences was constructed. RESULTS: The HA gene sequences ofA/HINlv analyzed segregated into three genetically distinct clades and were characterized by the appearance of amino acid variations that were progressively fixed in the field viral population under scrutiny. CONCLUSIONS: These data suggest an early co-circulation of genetically distinct A/HNINv variants and emphasize the importance of a close molecular surveillance to detect rapidly the spread of new viral variants and to define their epidemiological impact.

Emerging and re-emerging infections at the turn of the millennium.

After World War II, mankind believed that infectious diseases were on the way to being defeated. Unfortunately, they still are the second worldwide cause of death. Globalization changes promote the emergence of new infections and pandemics; international deliveries and travelling facilitate the dissemination of infectious agents; man-induced environmental changes create new opportunities for contacts between species, leading to infections in aberrant hosts, including man; global warming enables insects, a major vector of pathogens, to thrive in more countries. The main pandemics have been caused by viruses, such as HIV and novel subtypes of influenza viruses. In addition, prion proteins are a threat. The transmission of the Creutzfeld Jakob disease variant through blood transfusion and the recent discovery of prion protein in the spleen of a haemophilia patient are a matter of further concern. The end of the war against infectious diseases is not in sight. Mankind's battle with pathogens has lasted millennia and is destined to continue.

A 2010 update on occult hepatitis B infection.

Occult hepatitis B virus infection is a challenging issue whose virological and clinical relevance has been a source of long-lasting debate. By definition, OBI is characterized by the persistence of HBV-DNA in the liver tissue (and in some cases also in the serum) in absence of HBsAg. According to the HBV serological profile, OBI may be antibody (anti-HBc alone or together with anti-HBs) positive (seropositive OBI) or antibody negative (seronegative OBI). OBI is a complex biological entity with possible relevant clinical implications, mainly related to the intrahepatic persistence of viral cccDNA and to a strong suppression of viral replication and gene expression. Clinical observations suggest that OBI carriers may be a source of HBV transmission through blood transfusion or orthotopic liver transplantation (OLT). The state of suppression of viral replication and gene expression may be discontinued when an immunosuppressive status occurs, leading to typical hepatitis B with severe - and some times - fulminant course. The long-lasting persistence of the virus in the liver may provoke a very mild but continuing necro-inflammation that (if other causes of liver damage cohexist) may contribute over time to the progression of the chronic liver damage towards cirrhosis. In addition, OBI is supposed to be an important risk factor to HCC development since it maintains the pro-oncogenic properties typical of the overt infection.

[Biological risk prevention in agriculture and animal breeding: immunization strategies]. / Strategie vaccinali per la prevenzione del rischio biologico in agricoltura e zootecnia.

Vaccine preventable diseases are, so far, a main focus of Public Health programmes all over the world since people still die in consequence of Dyphteria or Tetanus. Biological risk is widely represented in agriculture and animal breeding, due to environmental characteristics and to injury typology. Moreover, aged people and migrants represent a significant part of the workforce. These two groups are, for instance, more exposed to Clostridium tetani infection because not fully immunized. Among infectious diseases that can affect agricultural workers, just tetanus can be well controlled by immunization programmes. Teaching and training activities are the most important tools to get protection against Leptospira interrogans, Salmonella spp and hepatitis E Virus infection. As for every training activity, linguistic and cultural barriers have to be taken into account.

Gene therapy of Hunter syndrome: evaluation of the efficiency of muscle electro gene transfer for the production and release of recombinant iduronate-2-sulfatase (IDS).

Mucopolysaccharidosis type II (MPSII) is an inherited disorder due to a deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). The disease is characterized by a considerable deposition of heparan- and dermatan-sulfate, causing a general impairment of physiological functions. Most of the therapeutic protocols proposed so far are mainly based upon enzyme replacement therapy which is very expensive. There is a requirement for an alternative approach, and to this aim, we evaluated the feasibility of muscle electro gene transfer (EGT) performed in the IDS-knockout (IDS-ko) mouse model. EGT is a highly efficient method of delivering exogenous molecules into different tissues. More recently, pre-treatment with bovine hyaluronidase has shown to further improve transfection efficiency of muscle EGT. We here show that, by applying such procedure, IDS was very efficiently produced inside the muscle. However, no induced IDS activity was measured in the IDS-ko mice plasma, in contrast to matched healthy controls. In the same samples, an anticipated and rapidly increasing immune response against the recombinant protein was observed in the IDS-ko vs control mice, although reaching the same levels at 5 weeks post-injection. Additional experiments performed on healthy mice showed a significant contribution of hyaluronidase pre-treatment in increasing the immune response.

Inhibition of anchorage-dependent cell spreading triggers apoptosis in cultured human endothelial cells.

When cultivated on substrates that prevent cell adhesion (the polymer polyhydroxyethylmethacrylate, bovine serum albumin, and Teflon), human endothelial cells (EC) rapidly lost viability with a half-life of approximately 10 h. Dying EC showed the morphological and biochemical characteristics of apoptosis. The apoptotic process of suspended EC was delayed by the protein synthesis inhibitor cycloheximide. To obtain information as to the mechanism involved in the apoptosis of suspended EC, we investigated whether adhesion to matrix proteins or integrin occupancy in EC retaining a round shape may affect EC suicide. EC bound to low coating concentration of either fibronectin or vitronectin, retaining a round shape and failing to organize actin microfilaments, underwent to rapid cell death; by contrast, cells on high substrate concentrations became flattened, showed actin microfilament organization, and retained viability. Addition of saturating amounts of soluble vitronectin to suspended round-shaped EC did not reduce the process of apoptosis. Finally, when suspended EC bound Gly-Arg-Gly-Asp-Ser-coated microbeads (approximately 10 microbeads/cell), yet retaining a round shape, the apoptotic process was not affected. Oncogene-transformed EC in suspension were less susceptible to cell death and apoptosis than normal EC. Overall, these data indicate that cell attachment to matrix or integrin binding per se is not sufficient for maintaining cell viability, and that cells need to undergo some minimal degree of shape change to survive. Modulation of interaction with the extracellular matrix can, therefore, be an important target for the control of angiogenesis.

Polymorphonuclear leukocyte adhesion triggers the disorganization of endothelial cell-to-cell adherens junctions.

Polymorphonuclear leukocytes (PMN) infiltration into tissues is frequently accompanied by increase in vascular permeability. This suggests that PMN adhesion and transmigration could trigger modifications in the architecture of endothelial cell-to-cell junctions. In the present paper, using indirect immunofluorescence, we found that PMN adhesion to tumor necrosis factor-activated endothelial cells (EC) induced the disappearance from endothelial cell-to-cell contacts of adherens junction (AJ) components: vascular endothelial (VE)-cadherin, alpha-catenin, beta-catenin, and plakoglobin. Immunoprecipitation and Western blot analysis of the VE-cadherin/catenin complex showed that the amount of beta-catenin and plakoglobin was markedly reduced from the complex and from total cell extracts. In contrast, VE-cadherin and alpha-catenin were only partially affected. Disorganization of endothelial AJ by PMN was not accompanied by EC retraction or injury and was specific for VE-cadherin/catenin complex, since platelet/endothelial cell adhesion molecule 1 (PECAM-1) distribution at cellular contacts was unchanged. PMN adhesion to EC seems to be a prerequisite for VE-cadherin/catenin complex disorganization. This phenomenon could be fully inhibited by blocking PMN adhesion with an anti-integrin beta 2 mAb, while it could be reproduced by any condition that induced increase of PMN adhesion, such as addition of PMA or an anti-beta 2-activating mAb. The effect on endothelial AJ was specific for PMN since adherent activated lymphocytes did not induce similar changes. High concentrations of protease inhibitors and oxygen metabolite scavengers were unable to prevent AJ disorganization mediated by PMN. PMN adhesion to EC was accompanied by increase in EC permeability in vitro. This effect was dependent on PMN adhesion, was not mediated by proteases and oxygen-reactive metabolites, and could be reproduced by EC treatment with EGTA. Finally, immunohistochemical analysis showed that VE-cadherin distribution was affected by PMN adhesion to the vessel wall in vivo too. This work suggests that PMN adhesion could trigger intracellular signals in EC that possibly regulate VE-cadherin /catenin complex disorganization. This effect could increase EC permeability and facilitate PMN transmigration during the acute inflammatory reaction.