Risk factors, atrial fibrillation and thromboembolic events.

AIM: The aim of this study was to evaluate the relation between risk factors for atrial fibrillation (AF) and thromboembolic complications. METHODS: We studied 480 patients (mean age: 71.2+/-11.6 years): 240 with paroxysmal AF, 240 with permanent AF. The association between AF and the presence of risk factors, cardiac and systemic disease was observed and the correlation with the occurrence of complications analyzed. RESULTS: Patients with AF had a high prevalence of the following conditions: hypertension, hypertensive heart disease (HHD), coronary artery disease, hyperthyroidism. Thromboembolism was observed in 26.6% of the patients. A correlation between the occurrence of a thromboembolic complication and the presence of one of the following risk factors for thromboembolism was observed: older age, diabetes mellitus, HHD and hyperfibrinogenemia. No correlation was detected between: female sex, arterial hypertension, hypercholesterolemia, smoking, and obesity. Exitus was observed in 7 patients with permanent AF. CONCLUSION: Older age, diabetes mellitus, HHD and hyperfibrinogenemia were strongly associated with the occurrence of thromboembolic complications. Patients with effectively pharmacologically controlled hypertension had not more frequently thromboembolic complications. A strict blood pressure control may prevent thromboembolic complications of AF.

Immunology of human rickettsial diseases.

Among human rickettsial diseases caused by micro-organisms of the genus Rickettsia (Order Rickettsiales; Family Rickettsiaceae), transmitted to human hosts through arthropod vectors, Mediterranean Spotted Fever, or Boutonneuse Fever, and Rocky Mountain Spotted Fever are considered to be important infectious diseases due to continued prevalence in the developed world, and potentially fatal outcome in severe cases. Proliferation of rickettsiae, at the site of the tick bite, results in focal epidermal and dermal necrosis (tache noire). Rickettsiae then spread via lymphatic vessels to the regional lymph nodes, and, via the bloodstream, to skin, brain, lungs, heart, liver, spleen and kidneys. The pathogen invades and proliferates in the endothelial cells of small vessels, target cells of rickettsial infection, destroying them, and spreading the infection to the endothelia of the vascular tree. The damage of the endothelium, and the subsequent endothelia dysfunction, is followed by the activation of acute phase responses, with alteration in the coagulation and in the cytokine network, together with a transient immune dysregulation, characterized by the reduction in peripheral CD4+ T lymphocytes.

Immunopathology of leishmaniasis: an update.

Leishmaniasis represents a severe, increasing, public health problem. The perspective of its control is highly dependent on research progress, on therapeutic manipulations of the immune system, and on vaccine development. There is a correlation between the clinical outcome of Leishmania infection and the cytokine response profile. While a protective immune response against Leishmania has been clearly identified to be related to the influence of a type-1 response and IFN-gamma production, the precise role of T helper (TH) 2 cytokines in non-healing infections requires further exploration. IL-4 and IL-13 (TH2 cytokines) can promote disease progression in cutaneous leishmaniasis, whereas IL-4 would appear to enhance protective type-1 responses in visceral leishmaniasis. Thus, the TH1/TH2 paradigm of resistance/susceptibility to intracellular parasites is probably an oversimplification of a more complicated network of regulatory/counter regulatory interactions. Moreover, the presence of antigen specific regulatory T cell subsets may provide an environment that contributes to the balance between TH1 and TH2 cells. Finally, the involvement of CD8 positive T cells has been described, but the modality of their function in this kind of infection has not been so far elucidated.

Relationship between specific serum IgE to Ascaris lumbricoides and onset of respiratory symptoms in Bangladesh immigrants.

The role of helminths in asthma and/or rhinitis and in allergic sensitization is still unclear. We assessed the relationship between Ascaris-specific IgE, respiratory symptoms and allergic sensitization in Bangladesh immigrants. 246 individuals were examined from 1996 to 2001. Serum total IgE, Ascaris IgE, specific IgE to inhalant allergens, skin prick tests (SPT) and parasitological evaluation of the stool were performed. Total serum IgE were significantly higher in Ascaris-IgE positive (> 0.35 kU/L) individuals (806.5 [409.0-1436.0] kU/L vs. 207.0 [127.0-332.5] kU/L; P < 0.0001) and in subjects with respiratory symptoms (413.0 [239.0-1096.0] kU/L vs. 259.5 [147.0-387.0] kU/L), (P < 0.0001), but not in SPT positive subjects (413.0 [179.0-894.0] kU/L vs. 404.6 [305.0-1201.0] kU/L (P = 0.5). Ascaris-specific IgE were detected in 48 subjects with respiratory symptoms (40.0%) and in 46 subjects without respiratory symptoms (36.5%) (P = 0.5). The SPT positivity was similar between Ascaris-IgE seropositive (38.2%) and Ascaris-IgE seronegative (38.1%) subjects (P = 0.9). Total IgE and length of stay in Italy correlated with SPT positivity (OR 5.6 [CI 95% 1.5-19.8], P = 0.007, and OR 1.5 [CI 95% 1.3-1.7], P< 0.0001), and with respiratory symptoms (OR 13.7 [CI 95% 3.0-62.4];, P = 0.0007, and OR 2.4 [CI 95% 1.9-3.0], P < 0.0001). Ascaris-IgE were negatively associated with SPT positivity (OR 0.3 [CI 95% 0.1-0.8], P = 0.02) and with respiratory symptoms (OR 0.1 [CI 95% 0.04-0.7], P = 0.01). Our findings favour the role of environmental factors in the development of respiratory symptoms in immigrants, irrespective of Ascaris-IgE.

Role of TLR4 receptor polymorphisms in Boutonneuse fever.

The genetics of the interaction between host and microbes plays an essential role in the survival of the individual and attainment of longevity. The activation of toll-like receptor (TLR)4 plays a key role in natural and clonotypic immune responses. We evaluated whether TLR4 genotype is a component of genetic background protective versus rickettsiosis and whether this background influences longevity. We genotyped for +896A/G TLR4 polymorphism 78 patients affected with Boutonneuse fever, 78 age-matched controls and 78 advanced age individuals from Sicily. The +869G allele, that attenuates receptor signalling, was significantly overrepresented in patients in comparison with age-matched controls. By analyzing data according to gender, this allele was significantly higher in female patients when compared to advanced age women. Pro-inflammatory responses are programmed to resist fatal infections. So, it is not surprising that the genetic background of people that survive to an advanced age may be protective against infections. However, this seems to occur in women but not in men. In a previous study, the +896G TLR4 allele was overrepresented in advanced age men and underrepresented in men affected by myocardial infarction. Thus, previous and present results tend to agree with the suggestion that men and women may follow different trajectories to reach longevity. For men it might be more important to control atherogenesis, whereas for women it might be more important to control infectious diseases.

Interleukin-15, as interferon-gamma, induces the killing of Leishmania infantum in phorbol-myristate-acetate-activated macrophages increasing interleukin-12.

The potential leishmanicidal activity of interleukin-15 (IL-15) was examined while priming with the cytokine phorbol-myristate-acetate (PMA)-activated macrophages and infecting them with Leishmania infantum parasites. The activation of macrophage cultures with IL-15 determined a significant anti-leishmanial activity, comparable with that induced by interferon-gamma (IFN-gamma). The killing of Leishmania in macrophages primed with IL-15, as well as with IFN-gamma, was followed by an increase in the IL-12 synthesis. The neutralization of IL-15 or IFN-gamma, by specific monoclonal antibodies (MoAb) caused a significant reduction in leishmanicidal activity. Furthermore, in PMA-activated macrophages, the neutralization of IL-12 production by a specific anti-IL-12 MoAb reduced leishmanicidal activity induced by IL-15 and IFN-gamma. Data indicate that IL-15 could have a role as an activator of leishmanicidal activity, directly or indirectly, by inducing IL-12 production.

Evaluation of an IgM-ELISA test for the diagnosis of human leptospirosis.

Leptospirosis is a zoonosis with a worldwide distribution very common in most countries. In Italy this acute febrile illness is more frequent in the Northern than in the Southern regions. In the period 1994-1996, the number of cases of Leptospirosis in Sicily was lower with respect to the northern-central regions (7.2% and 73.4% respectively). Between January 1990 and December 1999, a total of 9 leptospirosis cases were observed in the Regional Centre for Leptospirosis of Palermo. The patients were all males (age between 22 and 59 years) and their occupations varied. Laboratory diagnosis is performed by the classical microagglutination microscopical (MAT) but this test is very complex and time-consuming. This study compared the classical MAT with ELISA IgM by using 19 serum samples from 9 patients with confirmed leptospirosis. We also tested 23 serum samples from blood-donors and 29 serum samples from patients with other infectious diseases. By the MAT and the PanBio IgM ELISA all sera from patients were found to be positive. Our results indicate that MAT represents the test with the highest degree of specificity (100%), but ELISA is simpler to perform, considering the favourable degree of sensitivity (100%) and specificity (95.9%).

Rickettsial disease: classical and modern aspects.

Rickettsial diseases have been reassessed in recent years since they represent an important field in today's medicine. New agents have been described: some are non-pathogenic agents and the others are associated with well-defined or peculiar clinical patterns. In addition, different species of rickettsiosis are found in relation to the geographic areas of the world. Some agents may be defined as variants of older diseases whereas most of the newly described forms of rickettsiosis represent distinct entities with unique epidemiologial and clinical features. Probably the main news regards the group of the spotted fevers. An additional new aspect is linked to the medicine of travellers and tourists. However, this aspect may not be significant for the rickettsial diseases in relation to other human illnesses, such as malaria. Therefore, an investigation into the geographical origin of patients has to enter our routine medical work.

Safe and successful endoarterial infusion of liposomal amphotericin B in treatment of mucormycosis.

Mucormycosis is a rare invasive mycotic infection treated by antifungini or amphotericin B. We describe the case of a patient with septic fever and a necrotic lesion, with phlegmon of medial left thigh. Surgery was performed to drain the abscess content and to remove the necrotic tissue; mucormycosis was diagnosized by histological and culture tests and treated by intravenous amphotericin B. Since the lesion worsened, liposomal amphotericin B was directly infused into the left common iliac artery, with progressive improvement, and treatment was continued until complete recovery. Therefore, the endoarterial infusion of liposomal amphotericin B was a safe and successful treatment of advanced lesions of mucormycosis. In such lesions, intravenous general antibiotic administration probably is not sufficient to reach the whole infected area.

IL-15 in human visceral leishmaniasis caused by Leishmania infantum.

Interleukin (IL)-15 is a recently discovered cytokine with the ability to stimulate the proliferation activity of Th1 and/or Th2 lymphocytes. Here, we investigated the involvement of IL-15 in the immune response to Leishmania infantum infection by studying patients with visceral leishmaniasis (VL). We found that IL-15 is produced by leishmanial antigen (LAg)-stimulated peripheral blood mononuclear cells (PBMC) from active VL patients at a significantly higher level than those produced by cells from healed VL subjects or healthy controls. A significant increase in IL-15 serum blood levels was also observed in acute VL patients compared with healed ones. Furthermore, recombinant IL-15 had an appreciable effect in vitro in reducing IL-4 and increasing the production of IL-12 in response to LAg, but it was ineffective in altering the production of interferon-gamma (IFN-gamma). The production of endogenous IL-15 in acute VL patients appeared to be insufficient to activate both IFN-gamma and IL-12, as attested by the absence of modification of these two cytokines by neutralization experiments in the presence of anti-IL-15 monoclonal antibodies (MoAB). On the contrary, the neutralization of IL-15 increased IL-4 production. Together, these results indicate that endogenous IL-15 plays a role in the suppression of Th2-type cytokines, even though it does not enhance the production of Th1 cytokines in acute VL patients. Since IL-15, in the presence of anti-IL-4 MoAb, caused a further increase in IL-12 production and led to a significant production of IFN-gamma, one of its indirect effects on Th1 cell activation could be due to the latter's effect on Th2 cytokines such as IL-4. Therefore, our observations indicate that there is a potential for IL-15 to augment the T-cell response to human intracellular pathogens.

Amoxicillin-loaded polyethylcyanoacrylate nanoparticles: influence of PEG coating on the particle size, drug release rate and phagocytic uptake.

Polyethyleneglycol (PEG)-coated polyethylcyanoacrylate (PECA) nanoparticles loaded with amoxicillin were prepared and the influence of the PEG coating on the particle size, zeta potential, drug release rate and phagocytic uptake by murine macrophages was studied. Experimental results show that this colloidal drug delivery system could be useful for intravenous or oral administration. The profile of amoxicillin release from PECA nanoparticles system was studied under various conditions similar to those of some corporeal fluids. In all these experiments, amoxicillin release in the free form was studied by HPLC analysis. Experimental results showed that at pH 7.4 drug release rises when molecular weight of PEG added to polymerization medium increases; in human plasma on the contrary drug release is reduced as molecular weight of PEG rises. Phagocytosis was evaluated by incubating amoxicillin-loaded PECA nanoparticles with murine macrophages and determining the amount of phagocytized nanoparticles by dosing the amoxicillin present inside the macrophages. The results of this study showed significative differences between nanoparticles prepared in the presence or in the absence of PEG and demonstrated that the PEG coating reduces the macrophages uptake. These results suggest that nanoparticles prepared in the presence of PEG are stealth carriers, which could be an injectable colloidal system able to avoid MPS recognition after intravenous injection. Experimental data of drug release at pH 1.1 and in the presence of urease, taking into account the mucoadhesive properties of polyalkylcyanoacrylate nanoparticles and the activity of the amoxicillin versus Helicobacter pylori, suggest moreover that the colloidal drug delivery system obtained in our laboratory could be useful for the treatment of diseases caused by H. pylori by peroral administration.

The acute phase response in Sicilian patients with boutonneuse fever admitted to hospitals in Palermo, 1992-1997.

OBJECTIVES: To study the modifications of some components of the acute phase response (APR) in Sicilian patients with boutonneuse fever (BF) caused by Rickettsia conorii. METHODS: Sera from 500 Sicilian patients with confirmed BF were studied at the time of diagnosis and every week after treatment, and after recovery for the presence of various inflammatory mediators. Tumour necrosis factor alpha (TNFalpha), interleukin(IL)-6, IL-1alpha, IL-8, soluble TNF receptors (sTNF-R) and sIL-6R were assayed by commercially ELISA kits. C3, C4, factor B, C-reactive protein (CRP), fibrinogen, ceruloplasmin (Cp) and alpha(1)-antitrypsin (AAT) were assayed by a rate nephelometry. RESULTS: Interferon gamma (IFNgamma), IL-6, TNFalpha, and IL-10 cytokines were significantly modified, whereas IL-1 and IL-8 were not detectable in the blood in any phase of infection. sTNF-RI, sTNF-RII and sIL-6 were significantly increased in the first 2 weeks of infection, but sTNF-R levels were not related to the plasma levels of TNFalpha, whereas sIL-6 was directly related to serum IL-6 concentrations. C3, C4, factor B and CRP were significantly increased in the first 2 weeks of infection, but afterwards returned to the normal range, even though CRP was still high in the third week and C3 persisted high after the fourth week. Fibrinogen was high only in the first week in relation to the injury to the endothelial cells (ECs). The anti-inflammatory proteins, Cp and AAT, were extremely high in the first 2 weeks of infection acting as a buffer of APR activation. CONCLUSIONS: These results suggest that R. conorii is able to elicit, after invasion and proliferation in the ECs, the activation of APR. Further work is required to establish if active inhibitory mechanisms are operating during APR, or if there is a spontaneous decay in the initiation events.

Interleukin-12 in human boutonneuse fever caused by Rickettsia conorii.

Interleukin (IL)-12 contributes to the resistance against a number of intracellular pathogens. We examined the potential biological role of IL-12 by studying peripheral blood mononuclear cells (PBMC), its production and its effect on cytokine synthesis in 20 Sicilian patients with boutonneuse fever (BF) caused by Rickettsia conorii. Data indicate that PBMC from acute BF patients were able to produce IL-12 in response to in vitro stimulation with rickettsial antigen (Ag): this production was higher than that detected in healed patients. Monocytes were the main source of IL-12 by PBMC from BF patients. IL-12 secretion by in vitro Ag-stimulated PBMC from BF patients was potentiated by recombinant interferon gamma (IFN-gamma) or anti-IL-10 monoclonal antibodies (MoAbs). Furthermore, the treatment with anti-IL-12 MoAbs reduced the IFN-gamma synthesis. These results indicate that treatment of PBMC from acute BF patients with IL-12 shifted the response toward a Th1-type cytokine response. Furthermore, IL-12 and IFN-gamma are interdependent and they may be associated with the immunity against rickettsias.

Epidemiological trend of human leptospirosis in Italy between 1994 and 1996.

In the three-year period 1994 1996, 222 reports on human cases of leptospirosis were received by the Italian Ministry of Health. The average annual number of reports was 29.2% lower than in the preceding eight years. In all cases but two the infections were thought to have been acquired in Italy. As in previous years, the majority of cases was observed in the northern regions of the country (83.8%), mostly in males (88.9%). Cases occurred in all age groups, but were more common in the working-age population (15-64 years). There was no common-source outbreaks. The typical leptospiral seasonal course, with a peak in August, was observed. During 1994, leptospirosis was the reported cause of death in 19 patients. Mortality was higher among males than females. The overall fatality rate was 22.6%. During the study period, a total of 126 cases of leptospirosis were confirmed by the National Centre for Leptospirosis or one of the 12 Regional Leptospira Laboratories. Of the 103 patients for whom information on place of residence, contact with animals, occupational and recreational activities was available, 98 (95.1%) were people who live in rural areas or devote themselves to occupational or recreational activities at risk. The likely source of infection and the mode of exposure were known for 55 patients. Forty-five patients (81.8%) were likely infected by contaminating water (43 cases) or soil (2 cases), ten (18.2%) by direct contact with animals or animal urine. Both running (51.2%) and stagnant water (27.9%) have been reported as a source of infection. Rodents were implicated in 50.0% of the 10 cases involving animals. In comparison with the preceding eight-year period, the risk of contracting leptospirosis was found to have increased for recreational activities (from 34.7 to 38.2%) and decreased for occupational activities (from 45.8 to 32.7%). A large number of infections, however, was ascribed to accidental events (25.5%). As in the previous period, besides fever, the involvement of the liver was the most frequent clinical manifestation (70.8%). Influenza-like symptoms were the only signs of illness in 15.1% of cases. Infections by 9 different serogroups were detected. The most frequent antibodies were those against serovars icterohaemorrhagiae, poi, copenhageni and brattislava. The presence of co-agglutinins against serovars belonging to different serogroups prevented the identification of the presumptive infecting serogroup in 19.8% of subjects.

Comparison of the effects of fluticasone propionate, aqueous nasal spray and levocabastine on inflammatory cells in nasal lavage and clinical activity during the pollen season in seasonal rhinitics.

BACKGROUND: Treatment options for allergic rhinitis include antihistamines, decongestants, anticholinergics, cromolyn sodium and corticosteroids. As the nose is a small organ, comprising less than 1% of total body mass and surface area, it seems logical to confine treatment of rhinitis to the diseased organ. OBJECTIVE: To evaluate the effects of therapy with intranasal fluticasone propionate (FP), both on subjective symptoms and pathophysiological mechanisms, in rhinitis patients during pollen season when the patients were symptomatic. METHODS: We used a double-blind, placebo (PLA)-controlled, randomized, double dummy, parallel group study of the effect of 6 weeks treatment. The double-blind comparison was made between the following three treatments: FP aqueous nasal spray, 200 microg taken once daily, levocabastine (LEV) nasal spray, 200 microg taken twice daily and PLA nasal spray. Clinical evaluation and the levels of cells and mediators in nasal washing were performed before and after treatments. Twenty-four patients (11 men and 13 women, aged 17-50 years, mean age 30.1 +/- 8.5) with strictly seasonal allergic rhinitis to Parietaria entered the study. Clinical evaluation and the levels of inflammatory cells (eosinophils and activated eosinophils, i.e. EG2+) and their mediators (tryptase, eosinophil cationic protein, eosinophil protein X and neutrophil myeloperoxidase) in nasal-lavage were performed before and after treatments. RESULTS: Treatment with FP significantly increased, with respect to placebo, the percentage of days without sneezing (P < 0. 001), nasal blockage (P < 0.001), rhinorrhea (P < 0.001), nasal itching (P < 0.001). Furthermore, treatment with FP showed additional benefits with respect to LEV. The percentage of days without nasal blockage was significantly higher in the FP group that in the placebo group (P = 0.018). The same applied to rhinorrhea (P = 0.009). The percentages of days without sneezing and itching were instead not significantly different between the two groups. As expected, no significant differences were observed in baseline medians of the rhinitis symptom scores as well as in mean values of all mediators and eosinophils in nasal lavages of the various groups under study. After treatment the mean of subjective symptoms as well as all values in nasal lavage level fell significantly only in the FP group, whereas no significant changes were observed either in LEV or PLA groups. Accordingly, significant differences were observed at the end of the treatments between the values of fluticasone group vs LEV and PLA group values. Significant correlations between these values and symptom scores were found, according with literature data suggesting a pathogenetic role for these mediators and eosinophils in rhinitis. CONCLUSION: FP (200 microg once daily) affords a significant degree of improvement in rhinitis control during pollen season, as measured by subjective and objective parameters, compared with LEV (200 microg twice daily) and PLA. The therapeutic benefits of intranasal FP are reflected in, and may be caused by, the decrease in nasal inflammatory cells.

Differential up-regulation of circulating soluble selectins and endothelial adhesion molecules in Sicilian patients with Boutonneuse fever.

In 150 patients with Boutonneuse fever (BF), caused by Rickettsia conorii, we studied the plasma levels of soluble L-selectin (sL-selectin), vascular cell adhesion molecule-1 (sVCAM-1), intercellular adhesion molecule-1 (sICAM-1) and E-selectin (sE-selectin) in various phases of disease to clarify their role in disease evolution. Results indicate that during the acute phase of BF there is a significant increase in the serum levels of sL-selectin, sE-selectin, sVCAM-1 and sICAM-1. sL-selectin and sVCAM-1 returned to normal levels in the third week of disease, whereas sE-selectin and sICAM-1 persisted at significantly high levels even after the third week. The secretion of these soluble CAMs in BF is mainly the result of leucocyte expression and endothelial cell activation, but secretion also appears to mediate anti-inflammatory activities, moderating leucocyte adhesion and reducing in particular lymphocyte and monocyte infiltration. Only sL-selectin serum levels were found to correlate with the acute phase of infection characterized by fever.

Serum levels of soluble CD23 in patients with asthma or rhinitis monosensitive to Parietaria. Its relation to total serum IgE levels and eosinophil cationic protein during and out of the pollen season.

The diagnostic value for allergies of the low affinity IgE receptor and its soluble circulating fragment (sCD23) remains unclear. In particular, little is know about seasonal influences on serum sCD23 levels in subjects with pollen allergy. In the present study, to gain insight into pathophysiological role of sCD23, we have analyzed, in blood from patients allergic to Parietaria sCD23, IgE, and eosinophil cationic protein (ECP) serum levels. IgE were assessed as atopy markers and ECP as an inflammation marker. Patients were studied during and out of pollen season, and results were compared to those obtained in nonallergic subjects. The study population included 42 nonsmoking outpatients, living in Palermo (Sicily, Italy) or in other west Sicilian towns, with a clinical diagnosis of seasonal asthma or rhinitis and monopositive skin test to Parietaria pollen. The group of asthmatic subjects consisted of 25 patients who had one or more of the usual asthma symptoms (wheezing, dyspnea, and cough) only during the pollen season. The group of rhinitis patients consisted of 17 patients, who, during pollen season, had the nasal symptoms (nasal blockage, sneezing, nasal itching, and rhinorrhoea) but no signs of asthma. As a control group, we studied 10 nonatopic subjects from laboratory staff. They had no history of seasonal or perennial rhinitis, asthma, or urticaria and had negative skin tests to a panel of allergens. Soluble CD23, IgE, and ECP were assessed in blood during and out of pollen season. Total serum IgE levels were clearly higher in atopic patients, as classically established. Concerning sCD23 serum levels, a similar pattern of results was obtained. Accordingly, significant correlations were shown between the levels of sCD23 and IgE in all groups of patients. A completely different pattern was observed by analyzing serum ECP levels because ECP levels were significantly increased only in asthmatic patients during pollen season. Accordingly, no significant correlations were observed between the levels of sCD23 and those of ECP. Identifying immune factors associated with the development of atopy can enhance our understanding of the in vivo mechanisms involved and may have utility in paradigms designed to prevent diseases. As demonstrated by the close correlation with total serum IgE values and the lack of correlation with serum ECP values, serum levels of sCD23 appear to be an additional marker for the diagnosis of atopy but not for the follow-up of allergic diseases.