[Management model of chest pain in Medical Emergency Room and Chest Pain Unit of Policlinico Umberto I of Rome]. / Modello di gestione del dolore toracico in Pronto Soccorso Medico e nella Chest Pain Unit dell'Azienda Policlinico Umberto I di Roma.

In Italy one of the most common cause of access to the Emergency Departments is not traumatic chest pain, representing from the 6% to 10% of all the diagnoses. Admissions to the Emergency Department (DEA) of Policlinico Umberto I of Rome for non-traumatic chest pain, occurred between 2000 and 2008, were analyzed in this study. Out of 26,8910 admissions to the medical emergency room (PS), 21,088 (7.84%) were due to non-traumatic or precordial chest pain. Of these, 2881 (14%) patients had a diagnosis of myocardial infarction STEMI, NSTEMI and IA and 18,207 (86%) had a diagnosis of atypical chest pain, representing respectively 1.07% and 6.77% of all admissions to PS. About 27.62% of patients with atypical chest pain were discharged from the PS, 33.27% were hospitalized, 36.73% refused hospitalization, 1.68% were transferred elsewhere, and 0.7% did not uptake the visit. 85% of patients with myocardial infarction STEMI, NSTEMI and IA were hospitalized, 3.75% refused hospitalization, 8.82% were transferred elsewhere, and 1.71% died in the PS. Hospitalizations resulted often in unjustified and protracted length of hospital stays for clinical investigations, with negative repercussions for patients and costs. In the last years, the number of inappropriate hospitalizations progressively increased, partly as consequence of recourse to the court aiming at defining legal responsibility of the health board.Since avoiding inappropriate hospital admissions is an essential requirement for containing healthcare costs and improving the health service, Chest Pain Unit has been established. Its responsibility is to recognize and promptly treat patients with chest pain and acute coronary syndrome. As well, it is responsible to quickly discharge patients with chest pain at low and intermediate risk of acute coronary insufficiency, after careful clinical assessment lasting 24-36 hours.

Presence of effector CD8+ T cells in hepatitis C virus-exposed healthy seronegative donors.

CTL responses against multiple hepatitis C virus (HCV) epitopes were detected in 7 of 29 (24.1%) healthy family members (HFM) persistently exposed to chronically HCV-infected patients (HCV-HFM). These precursor CTL were at very low or undetectable frequencies, as determined by limiting dilution analysis. However, when HCV-specific effector CD8+ T cells, freshly isolated from PBMC of HCV-HFM, were assessed by a sensitive enzyme-linked immunospot assay, their frequencies were severalfold higher than those of precursor CTL. These results indicate that the two assays detect two functionally distinct T cell populations and that the effector cells are not assayed by the 51Cr-release assay. Furthermore, the combination of cell depletion and enzyme-linked immunospot analyses showed that the effector cells were confined into a CD8+ CD45RO+ CD28- population. The persistence of effector CD8+ T cells specific for both the structural and nonstructural viral proteins in uninfected HCV-HFM, suggest that: 1) an immunological memory is established upon a subclinical infection without any evidence of hepatitis, in a large cohort of HCV-exposed individuals; 2) because these cells required neither restimulation nor the addition of particular cytokines in vitro for differentiating in effectors, they should be capable of prompt HCV-specific effector function in vivo, possibly providing antiviral protection; and 3) the maintenance of effector T cell responses may be sustained by persisting low-level stimulation induced by inapparent infections.

HLA-DM polymorphisms do not associate with multiple sclerosis: an association study with analysis of myelin basic protein T cell specificity.

The MHC region on 6p harbors at least one susceptibility gene for multiple sclerosis (MS). Within this region, HLA-DM loci are of interest being involved in class II antigen processing. We investigated the association of HLA-DM polymorphisms with MS. Sixty-three patients with MS and 46 healthy controls from continental Italy were typed for HLA-DM polymorphisms and HLA-DRB1 alleles. Besides, among the donors characterized for the DM polymorphisms, we considered 6 MS patients previously studied for the fine specificity of their MBP-specific T lymphocyte lines (TLL). The frequencies of allelic variants at the DMA and DMB loci were similar between MS patients and controls, even when HLA-DRB1*1501 positive and negative donors were analyzed separately. Patients with predominant responses to different MBP epitopes did not differ for their HLA-DM haplotype while patients with predominant responses to the same MBP epitope could present different HLA-DM haplotypes. HLA-DM polymorphisms do not associate with MS and may not affect specific patterns of T cell responses to MBP.

Down-regulation of cell-surface CD4 co-receptor expression and modulation of experimental allergic encephalomyelitis.

Pre-immunization with autoantigens confers resistance in experimental models of autoimmune diseases. Since non-self molecules can also be protective, it is conceivable that part of the effect rests on a non-specific attenuation of the immune response. This study is aimed at identifying mechanisms by which pre-immunization with a moiety suspended in incomplete Freund's adjuvant (IFA) protects from experimental allergic encephalomyelitis (EAE). Lewis rats were immunized with each of either concanavalin A, lipopolysaccharide, bovine serum albumin, 70 or 65 kDa heat shock proteins, or myelin basic protein. All moieties were given in IFA 3 weeks prior to EAE induction. Serial cytofluorimetric monitoring of B cells and of the alpha beta TCR+, CD4+, CD8+, CD45high and CD45low cells was performed. IFN-gamma and IgG1 production was evaluated in parallel. All moieties were able to attenuate or abrogate the clinical signs of EAE. At day 4 and 10 after EAE induction, the surface expression of the CD4 molecule was down-regulated on T lymphocytes. This down-regulation was most evident in animals with the highest degree of clinical protection. By day 21 post-immunization, CD4 expression was restored. The same animals also showed an increase in the B cell percentage and Th2-related IgG1 production while IFN-gamma secretion was reduced. Pre-immunization with diverse antigens suspended in IFA confers resistance to EAE induction. The down-regulation of the CD4 co-receptor accompanied by events suggestive of an immune deviation may be a general mechanism that contributes to the protection.