Paola Bonara

Serum Hepcidin and Macrophage Iron Correlate With MCP-1 Release and Vascular Damage in Patients With Metabolic Syndrome Alterations

Objective—Increased body iron stores and hepcidin have been hypothesized to promote atherosclerosis by inducing macrophage iron accumulation and release of cytokines, but direct demonstration in human cells is lacking. The aim of this study was to evaluate the effect of iron on cytokine release in monocytes ex vivo and the correlation with vascular damage and to evaluate the relationship among serum levels of hepcidin, cytokines, and vascular damage in patients with metabolic syndrome alterations. Methods and Results—Manipulation of iron status with ferric ammonium citrate and hepcidin-25 induced monocyte chemoattractant protein (MCP)-1 and interleukin-6 in human differentiating monocytes of patients with hyperferritinemia associated with the metabolic syndrome (n=11), but not in subjects with hemochromatosis or HFE mutations impairing iron accumulation (n=15), and the degree of induction correlated with the presence of carotid plaques, detected by echocolor-Doppler. In monocytes of healthy subjects (n=7), iron and hepcidin increased the mRNA levels and release of MCP-1, but not of interleukin-6. In 130 patients with metabolic alterations, MCP-1 levels, as detected by ELISA, were correlated with hepcidin-25 measured by time-of-flight mass spectrometry (P=0.005) and were an independent predictor of the presence of carotid plaques (P=0.05). Conclusion—Hepcidin and macrophage iron correlate with MCP-1 release and vascular damage in high-risk individuals with metabolic alterations.

Novel mode of action of iloprost: in vitro down-regulation of endothelial cell adhesion molecules.

Iloprost is a stable prostacyclin analog commonly employed in the treatment of peripheral vascular disease and also indicated in the treatment of patients affected by systemic sclerosis (SSc) in the presence of severe Raynauds phenomenon (RP). Several mechanisms of action of the drug other than vasodilation and antiplatelet effect have been demonstrated that may be involved in the exertion of its clinical efficacy. Aim of the present study was to investigate whether iloprost down-regulated lymphocyte adhesion to endothelium through a modulation of adhesion molecule expression on the surface of endothelial cells. In the presence of iloprost, both lymphocyte adhesion and IL-1 stimulated expression of ICAM-1 and ELAM-1 exhibited a significant reduction, while unstimulated adhesion molecule expression was not significantly affected. Our results confirm that iloprost is able to down-regulate lymphocyte adhesion to endothelial cells and indicate that endothelium itself could be target of iloprost administration. Attenuation of the inflammatory response through modulation of cellular interactions could be suggested as a potential mechanism of action of iloprost, when used in the treatment of pathological conditions characterized by endothelial activation.

Induction of CD69 activation molecule on human neutrophils by GM-CSF, IFN-γ, and IFN-α

Abstract The CD69 glycoprotein is an early activation antigen of T and B lymphocytes but it expression is induced in vitro on cells of most hematopoietic lineages, including neutrophils after stimulation with PMA or fMLP. In this study, we investigated whether CD69 expression on human neutrophils could be modulated by inflammatory or anti-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, G-CSF, GM-CSF, TNF-α, TGF-β, IFN-α, IFN-γ). Resting neutrophils from healthy subjects did not express CD69 on the cell surface; moreover, a preformed intracellular pool of CD69 was not evident in these cells. CD69 was barely detectable on these cells after overnight incubation in medium while overnight incubation with GM-CSF, IFN-γ or IFN-α significantly induced CD69 expression on neutrophils with GM-CSF appearing to be the most potent inducer. This induction was dependent on a new protein synthesis as it was significantly inhibited by cycloheximide (about 50% inhibition). CD69 cross-linking on GM-CSF-primed neutrophils sinergized with LPS and increased TNF-α production and secretion suggesting a role for CD69-positive neutrophils in the pathogenesis and maintenance of different inflammatory diseases.

Rituximab treatment in a patient with severe thyroid-associated ophthalmopathy: Effects on orbital lymphocytic infiltrates

Rituximab (RTX) has been shown in previous work to improve thyroid-associated ophthalmopathy (TAO), but very little data is available on the effects of RTX in the target tissues. We studied the effects of RTX on peripheral lymphocytes and on the intra-orbital infiltrates in one patient with severe TAO who was treated with two cycles of therapy. Intra-orbital tissues derived at decompression from 3 patients with moderate-severe and 1 with severe TAO, treated with standard immunosuppression, were studied as controls. Peripheral blood lymphocytes were analyzed throughout the study period, while intra-orbital tissue lymphocytes at decompression. In the patient treated with RTX visual field and acuity improved in response to peripheral CD 20+ cell depletion, although there was a proportion of persisting CD 19+ cells. After RTX re-treatment the patients optic nerve function improved only transiently. The number of CD 20+ cells was lower in orbital tissues (0-1%) than in the peripheral blood (3%). A greater percentage of CD 19+ was observed in the orbits compared to the periphery, most of which were CD 19+5+ (80%). By immunohistochemistry, orbital tissues from all control patients showed CD 20+ and CD 3+ cells, independently of the duration of TAO and of the treatment with either steroids or radiotherapy. This is the first report on the therapeutic effect of RTX in active, severe TAO associated to the depletion of intra-orbital CD 20+ lymphocytes. After RTX, CD 19+5+ lymphocytes were shown to be 2-3 times more prevalent in the orbital infiltrates, compared to CD 20+ cells. Persistence of autoreactive cells is believed to be related to TAO relapse.

Susceptibility to HIV infection and AIDS in Italian haemophiliacs is HLA associated

Summary. We compared the frequencies of HLA antigens in two matched groups of 31 HIV‐seronegative and 31 HIV‐seropositive haemophiliacs, exposed during the years 1981–85 to comparable amounts and batches of presumably infectious clotting factor concentrates. The frequency of A2 was significantly higher in HIV‐seropositive than in seronegative haemophiliacs, with a relative risk (RR) of seroconversion of 3–92, whereas both Bw52 and DR4 were negatively associated with it. We also studied the distribution of HLA antigens in a larger group of 76 HIV‐seropositive haemophiliacs, who were at different clinical stages of HIV infection (CDC classes II‐IV) but were comparable for age and time elapsed since seroconversion. DR3 and DQw2 antigens were, particularly when concomitantly present, associated with a high risk of developing symptomatic HIV infection (RR = 11.79 and 25.33). Our data suggest that the HLA region controls susceptibility to infection with HIV and its progression to symptomatic disease in Italian haemophiliacs.

Small Dose of Rituximab for Graves Orbitopathy: New Insights Into the Mechanism of Action

citing role as increased levels of dopamine have been shown to cause choroidal vasodilation. The time course of effusion development in this case is similar to that with topiramate. This suggests that if bupropion use were causative, one of its major active metabolites, hydroxybupropion or theobupropion (both with half-lives similar to that of topiramate), may be responsible. Both metabolites inhibit dopamine and norepinephrine reuptake; thus, norepinephrine could also have a role. Bilateral effusions have been reported with venlafaxine hydrochloride, a norepinephrine and serotonin reuptake inhibitor. Bupropion is a common medication, and it is unclear why other cases have not been reported. If bupropion use were causative in this case, the absence of other similar reports may reflect underreporting; alternatively, this patient may harbor a rare, private polymorphism that causes bupropion or one of its metabolites to become a particularly potent choroidal vasodilator.

Effect of adalimumab on neutrophil function in patients with rheumatoid arthritis

Neutrophils are known to be targets for the biological activity of tumour necrosis factor (TNF)-α in the pathogenensis of rheumatoid arthritis (RA). Therefore, these cells may be among the targets of anti-TNF-α therapy. In this study we evaluated the effect of therapy with adalimumab (a fully human anti-TNF-α mAb; dosage: 40 mg subcutaneously every other week) on certain phenotypic and functional aspects of neutrophils obtained from 10 selected patients with RA and 20 healthy control individuals. Peripheral blood neutrophils were obtained at baseline and during anti-TNF-α therapy (2, 6 and 12 weeks after the first administration of adalimumab). All patients had been receiving a stable regimen of hydroxychloroquine, methotrexate and prednisone for at least 3 months before and during the study. Baseline neutrophil chemotaxis was significantly decreased in RA patients when compared with control individuals (P < 0.001). Two weeks after the first administration of adalimumab, chemotactic activity was completely restored, with no differences noted between patients and control individuals; these normal values were confirmed 6 and 12 weeks after the start of anti-TNF-α therapy. Phagocytic activity and CD11b membrane expression on neutrophils were similar between RA patients and control individuals; no modifications were observed during TNF-α neutralization. The production of reactive oxygen species, both in resting and PMA (phorbol 12-myristate 13-acetate)-stimulated cells, was significantly higher in RA patients at baseline (P < 0.05) and was unmodified by anti-TNF-α mAb. Finally, we showed that the activation antigen CD69, which was absent on control neutrophils, was significantly expressed on neutrophils from RA patients at baseline (P < 0.001, versus control individuals); however, the molecule was barely detectable on cells obtained from RA patients during adalimumab therapy. Because CD69 potentially plays a role in the pathogenesis of arthritis, our findings suggest that neutrophils are among the targets of anti-TNF-α activity in RA and may provide an insight into a new and interesting mechanism of action of anti-TNF-α mAbs in the control of inflammatory arthritis.

Severity assessment of healthcare-associated pneumonia and pneumonia in immunosuppression

The study compares the ability of the PSI (pneumonia severity index), CURB-65 (confusion, urea >7 mol·L−1, respiratory rate ≥30 breaths·min−1, blood pressure <90 mmHg systolic or ≤60 mmHg diastolic, and age ≥65 yrs), CURB and CRB-65 scales and the Severe Community-Acquired Pneumonia (SCAP) score to predict 30-day mortality in healthcare-associated pneumonia (HCAP) patients, and analyses differences in the demographics, aetiology and outcomes of community-acquired pneumonia (CAP), HCAP and pneumonia in immunocompromised patients. 629 consecutive patients admitted to a tertiary care university hospital were prospectively categorised as having CAP (n=322) or HCAP (n=307), and the HCAP patients were further sub-divided into those who were immunocompromised (n=219) or immunocompetent (n=88). The 30-day mortality rate was 9.0% in the CAP group and 24.1% in the HCAP group. In the HCAP group, the PSI and SCAP scores had similar prognostic power (area under the curve (AUC) of 0.68 and 0.67, respectively) and performed better than the CURB-65 score (AUC ≤0.62). Among the immunocompetent HCAP patients, the PSI and CURB-65 scores were more sensitive than the others at every threshold, whereas SCAP was more specific than both of these. In the immunocompromised group, the PSI was highly sensitive but poorly specific at all thresholds. Our results suggest that prognostic tools should be designed for subsets of HCAP patients.

Peripheral lymphocytes and intracellular cytokines in C282Y homozygous hemochromatosis patients

BACKGROUND/AIMS Several abnormalities in the immune status of hereditary hemochromatosis patients have been reported. We evaluated the peripheral blood lymphocytes phenotype and cytokine profile of CD8(+) and CD4(+) T cells in C282Y homozygous hereditary hemochromatosis patients compared to control subjects. METHODS Peripheral blood lymphocytes from 17 asymptomatic patients and 14 control subjects were analyzed. We determined the distribution of lymphocyte subsets and investigated at single-cell level by flow-cytometry the potential of cytokines production. The frequency of cytokine (interferon gamma, tumor necrosis factor alpha, interleukin 2 (IL-2), IL-4, IL-5, IL-10 and IL-13) producing cells was assessed in total T-lymphocytes, CD3(+)CD8(+) and CD3(+)CD4(+) subsets. RESULTS The patients studied showed a significant decrease of total lymphocyte count, T CD4(+)CD3(+), CD28(+), CD8(+)CD28(+) lymphocytes and natural killer (NK) CD56(+)CD16(+)CD3(-) cells. The reduction of CD28(+) and CD8(+)CD28(+) lymphocyte count was inversely related to transferrin saturation index. An increase in the ability of T-cells to produce all the cytokines studied and a major increase in IL-4 and IL-10 production in the CD3(+)CD8(+) subset was found. Our results demonstrate that activated Th1 and Th2 lymphocytes coexist in the peripheral blood of hereditary hemochromatosis patients and that T-cytotoxic (Tc) 2 subset is more expanded than in control population. CONCLUSIONS The association of a decreased number of T CD8(+) cytotoxic lymphocytes and NK cells, and the development of Tc2 cells in asymptomatic C282Y homozygous patients represents an imbalance in their immune function that might contribute to the high incidence of hepatocarcinoma.

Regulatory CD8+ T cells control thyrotropin receptor-specific CD4+ clones in healthy subjects

One of the mechanisms ensuring immunological unresponsiveness or tolerance depends on the action of CD8(+) lymphocytes. In this paper, we report that, in healthy subjects, a subset of CD8(+)CD28(-) T cells suppresses the specific response to TSH receptor (TSHR) of CD4(+) clones. Suppression was highly specific, required cell-cell interaction, and was not mediated by cytotoxicity. Co-incubation of CD8(+) and CD4(+) clones, followed by the removal of the CD8(+) cells from the cultures before testing CD4(+) responsiveness to TSHR, demonstrated that CD4(+) cells were anergic since they showed low response to the antigen and a significant impairment of IL-2 production. In CD8-mediated anergy induction, the T-cell receptor (TCR) on both CD4(+) and CD8(+) cells seems to play a role. Our results indicate that one of the mechanisms ensuring peripheral tolerance involve CD8(+)CD28(-) cells. A disregulation in the control of autoreactive clones by this subset might be important for the onset of autoimmune thyroid diseases.