Beatrice Greco

Evaluation of cellular immune responses and soluble mediators in patients with chronic hepatitis C virus (cHCV) infection.

In 54 patients with cHCV infection, peripheral immune responsiveness and soluble mediator release were evaluated. Results demonstrate that in these patients phagocytosis and killing capacities exerted by polymorphonuclear cells and monocytes were profoundly depressed. At the same time, absolute numbers of CD3+, CD8+ and CD16+ cells were reduced, while the CD4(+)-CD8+ dependent antibacterial activity was also impaired. With special reference to soluble mediators, elevated amounts of both soluble interleukin-2 receptor and soluble intercellular adhesion molecule-1 were detected in sera of patients. By contrast, serum levels of tumor necrosis factor-alpha were within normal ranges, whereas interferon-gamma serum concentrations were decreased. Of note, in 18.5% of cHCV patients circulating levels of bacterial lipopolysaccharides (LPS) were detected by means of Limulus assay. In the Limulus+subset of patients, absolute numbers of CD14+ cells were reduced in a significant manner, this implying a putative monocyte-LPS interaction. In conclusion, the overall results indicate a condition of peripheral immune depression in cHCV patients with an exaggerated shedding of various mediators endowed with noxious effects for the host.

Soluble (s) CD14 and plasmatic lipopolysaccharides (LPS) in patients with chronic hepatitis C before and after treatment with interferon (IFN)-α

CDI4 is a monocyte/polymorphonuclear cell receptor for lipopolysaccharide (LPS)-LPS Binding Protein (LBP), which mediates most of the toxic effects exerted by such a bacterial component in the host. Here, we provide evidence that sCD14 and interferon (IFN)-gamma serum levels are significantly higher in chronic hepatitis C (CH-C) patients than those detected in normal donors. On the other hand, CD4+/CD8+ antibacterial activity is depressed, thus facilitating entry of bacteria into the host. Of note, all these immune parameters are not modified by in vivo IFN-alpha administration over a period of one year. Finally, after 12 months of IFN-alpha treatment number of CH-C patients with detectable levels of plasmatic LPS increased, thus indicating a continuous release of LPS into the host and also suggesting a putative pathogenetic role for sCD14 LPS-LBP complex in subjects affected by CH-C virus infection.

Failure of imidocarb dipropionate to eliminate Hepatozoon canis in naturally infected dogs based on parasitological and molecular evaluation methods.

The efficacy of imidocarb dipropionate for the treatment of Hepatozoon canis infection was studied in three naturally infected asymptomatic dogs followed longitudinally over 8 months. Response to treatment was followed by monitoring blood counts, parasitemia levels in blood, parasite in concentrated buffy-coat smears and by PCR. The dogs were initially treated with a low dose of 3 mg/kg imidocarb dipropionate twice a month and when parasitemia persisted after five treatments, with the regular dose of 6 mg/kg. In one dog, H. canis gamonts were no longer detectable by blood and buffy-coat microscopy after 2 months of therapy with 6 mg/kg while in the two other dogs gamonts were intermittently found in blood but persistently detectable in buffy-coat smears during the whole study period. Furthermore, combined therapy with doxycycline monohydrate administered at 10 mg/kg/day PO for 4 weeks also failed to eliminate H. canis. PCR revealed that parasite DNA was present in the blood of all dogs at all sampling dates regardless of treatment refuting the effectiveness of treatment suggested by negative blood microscopy. Detection of H. canis in buffy coat was found to be twice as sensitive than by blood smear and detection by PCR was even more sensitive revealing infection in eight samples (16% of total samples) negative by blood and buffy-coat microscopy. In conclusion, imidocarb dipropionate was not effective in eliminating H. canis from dogs treated repeatedly over 8 months. Microscopical detection is not sufficient for the evaluation of treatment response in H. canis infection and follow up by molecular techniques is recommended.

Acute-Phase Proteins in Dogs Naturally Infected with Leishmania infantum During and After Long-term Therapy with Allopurinol

Sasanelli, M., Paradies, P., de Caprariis, D., Greco, B., De Palo, P., Palmisano, D. and Carelli, G., 2007. Acute-phase proteins in dogs naturally infected with Leishmaniainfantum during and after long-term therapy with allopurinol. Veterinary Research Communications, 31(Suppl. 1), 335–338

Retrospective study of hemoparasites in cattle in southern Italy by reverse line blot hybridization.

ABSTRACT Tick-borne diseases are widespread in tropical and temperate regions and are responsible for important economic losses in those areas. In order to assess the presence and prevalence of various pathogens in southern Italy, we retrospectively analyzed cattle blood samples collected for a previous study in 2000 using reverse line blot (RLB) hybridization. The study had been carried out in three regions of southern Italy on 1,500 randomly selected and apparently healthy adult cattle. RLB showed that 43.7% of the cattle were positive for nine different species of hemoparasites with either a single infection or a mixed infection. Theileria buffeli was the most common species found, being present in 27.3% of the animals, followed by Anaplasma marginale in 18.1%, Anaplasma centrale in 13.8%, Babesia bigemina and Anaplasma bovis in 4.2%, Anaplasma phagocytophilum in 1.7%, Babesia bovis in 1.6%, Babesia major in 0.2% and Babesia divergens in 0.1%. Complete blood counts showed different degrees of anemia in 363 animals (24.2%) and of these, 169 were RLB-positive for at least one pathogen. Among the ticks that were collected from the cattle, the following species were identified: Rhipicephalus bursa, Ixodes ricinus, Hyalomma marginatum, Boophilus annulatus, Dermacentor marginatus and Haemaphysalis (sulcata, parva, inermis and punctata). The results obtained confirmed the spread of endemic tick-borne pathogens in the regions studied.

Downregulation of Human Polymorphonuclear Cell Activities Exerted by Microorganisms Belonging to the α-2 Subgroup of Proteobacteria (Afipia Fs and Rochallmaea Henselae)

Intracellular pathogens have evolved effective mechanisms in order to survive in an intracellular environment, thus avoiding destruction by phagocytic cells. In this regard, a correlation between resistance to phagocytic killing and expression of pathogenic potency has been established. In this report, we have studied the interaction between human polymorphonuclear cells (PMN) and two gram-negative microorganisms, Afipia felis and Rochalimaea henselae, which belong to the alpha-2 subgroup of the class Proteobacteria. A. falis has been previously proposed as the causative agent of Cat Scratch Disease (CSD), but several recent lines of evidence attribute a major role to R. henselae. Of note, CSD is a syndrome characterized by a chronic lymphoadenopathy, involving macrophages and endothelial cells with a progression towards a granulomatous process and/or angiogenesis. Since members of the alpha-2 subgroup of Proteobacteria have the property to survive intracellularly, we have evaluated the effects exerted by A. felis and R. henselae on human PMN in terms of chemotaxis locomotion, degranulation and oxidative metabolism. Results will show an impairment of PMN activities as a consequence of the challenge with both microrganisms. In particular, inhibition of PMN oxidative function occurred either as result of a direct exposure to both A. felis and R. henselae or when PMN were primed by bacteria for the N-formyl-methionyl-leucyl-phenylalanine enhancement of the oxidative burst. These findings may account for the ability of A. felis and R. henselae to survive within PMN as expression of a further mechanism of pathogenic potency, influencing also the nature and the evolution of inflammatory response in the lesion sites.

Monitoring the reverse to normal of clinico-pathological findings and the disease free interval time using four different treatment protocols for canine leishmaniosis in an endemic area

Twenty-four dogs naturally infected by Leishmania spp. were treated with four different protocols using meglumine antimoniate (aNm) and allopurinol in combination or in monotherapy. Aiming to compare the efficacy of the different treatments the reverse to normal of clinico-pathological findings and the disease free interval time (DFIT) were evaluated. Treated dogs were monitored for 1 year and, in absence of relapses, the DFIT was postponed to the last available follow-up. Seven dogs treated with aNm alone showed relapses during the year of observation. In the group of dogs treated with the combination of aNm (50 mg/kg/SC 12 hourly up to clinico-pathological recovery) and allopurinol (15 mg/kg/PO 12 hourly administered for 6months) no relapses were registered in the year of monitoring and the DFIT reached up to 65 months. Our results showed that this combination represents the best choice to treat canine leishmaniosis compared to other protocols.

Endotoxins, cytokines, and neuroimmune networks with special reference to HIV infection.

The mutual interplay between the nervous system and the immune system has been the object of extensive studies in either conditions of stress or human diseases such as multiple sclerosis, psychiatric disorders, and migraine.’” Initial studies by Selye4 demonstrated activation of the hypothalamus-pituitary-adrenal axis in normal animals in response to stressful events; these effects were similar to the wasting syndrome that follows the experimental administration of bacterial endotoxins or lipopolysaccharides

Immunological Effects Following Administration of Interferon-α in Patients with Chronic Hepatitis C Virus (cHCV) Infection

The immunological effects of interferon (IFN)-alpha administration were evaluated in 15 patients with cHCV infection. Individuals were treated with 6 MU of lymphoblastoid IFN-alpha three times a week for 6 months and with 3 MU three times a week for an additional 6 months. Patients were divided into responders (12 subjects) and nonresponders (3 subjects), respectively, according to alanine aminotransferase serum levels at the end of treatment. Before therapy (T0), absolute numbers of CD3+, CD4+, CD8+, CD14+ and CD16+ cells were significantly reduced in both groups when compared to normal values. At the same time, all patients displayed a profound decrease of phagocytosis and killing exerted by both polymorphonuclear cells (PMN) and monocytes (MO). However, MO Killing resulted to be normal in the responder group. With special reference to T cell function, T cell mediated antibacterial activity, using Salmonella typhi as a target, was also significantly reduced. After therapy (T12), in responder patients a significant increase of CD3+, CD4+, CD14+ and CD16+ cell absolute numbers was observed, while phagocytic and T cell functions were still depressed. Among the nonresponders, in two of three patients IFN-alpha administration gave rise to an increase (above normality) of CD3+, CD4+, CD8+, CD14+, CD16+ and CD20+ cell absolute numbers, while in one patient the same markers dramatically dropped below normal range. In two patients, antibacterial activity was significantly augmented by IFN-alpha treatment, whereas in one patient no modification was observed. Finally, in the same patients IFN-alpha did not correct PMN and MO pretreatment deficits.

Triazolobenzodiazepines Exert Immunopotentiating Activities on Normal Human Peripheral Blood Lymphocytes

Previous studies have demonstrated that benzodiazepines (BDZ) (e.g. diazepam) inhibit immune responsiveness. Since these drugs are largely used in psychiatric patients it is of great importance to verify the existence of different types of BDZ, which are not suppressive for the immune system. In this framework, our results indicate that alprazolam and triazolam, two triazolo-BDZ, do not modify in vitro phagocytosis and killing exerted by normal human polimorphonuclear cells and monocytes. On the contrary, they significantly enhance T lymphocyte-dependent antibacterial activity in normal donors. These data support the concept that triazolo-BDZ and, in particular, alprazolam may represent more appropriate drugs for the treatment of psychiatric patients (e.g. patients with phobic disorders and/or migraine) who display immunodeficits.