Over the last decade, several studies have extensively reported that activated natural killer (NK) cells can kill autologous immature dendritic cells (DCs) in vitro, whereas they spare fully activated DCs. This led to the proposal that activated NK cells might select a more immunogenic subset of DCs during a protective immune response. However, there is no demonstration that autologous DC killing by NK cells is an event occurring in vivo and, consequently, the functional relevance of this killing remains elusive. Here we report that a significant decrease of CD11c+ DCs was observed in draining lymph nodes of mice inoculated with MHC-devoid cells as NK cell targets able to induce NK cell activation. This in vivo DC editing by NK cells was perforin-dependent and it was functionally relevant, since residual lymph node DCs displayed an improved capability to induce T cell proliferation. In addition, in a model of anti-cancer vaccination, the administration of MHC-devoid cells together with tumor cells increased the number of tumor-specific CTLs and resulted in a significant increase in survival of mice upon challenge with a lethal dose of tumor cells. Depletion of NK cells or the use of perforin knockout mice strongly decreased the tumor-specific CTL expansion and its protective role against tumor cell challenge. As a whole, our data support the hypothesis that NK cell-mediated DC killing takes place in vivo and is able to promote expansion of cancer-specific CTLs. Our results also indicate that cancer vaccines could be improved by strategies aimed at activating NK cells.

Human NK cells can be divided into CD56dimCD16+ killer Ig-like receptors (KIR)+/− and CD56brightCD16− KIR− subsets that have been characterized extensively regarding their different functions, phenotype, and tissue localization. Nonetheless, the developmental relationship between these two NK cell subsets remains controversial. We report that, upon cytokine activation, peripheral blood (PB)-CD56bright NK cells mainly gain the signature of CD56dim NK cells. Remarkably, KIR can be induced not only on CD56bright, but also on CD56dim KIR− NK cells, and their expression correlates with lower proliferative response. In addition, we demonstrate for the first time that PB-CD56dim display shorter telomeres than PB- and lymph node (LN)-derived CD56bright NK cells. Along this line, although human NK cells collected from nonreactive LN display almost no KIR and CD16 expression, NK cells derived from highly reactive LN, efferent lymph, and PB express significant amounts of KIR and CD16, implying that CD56bright NK cells could acquire these molecules in the LN during inflammation and then circulate through the efferent lymph into PB as KIR+CD16+ NK cells. Altogether, our results suggest that CD56brightCD16− KIR− and CD56dimCD16+KIR+/− NK cells correspond to sequential steps of differentiation and support the hypothesis that secondary lymphoid organs can be sites of NK cell final maturation and self-tolerance acquisition during immune reaction.

Indoleamine 2,3-dioxygenase (IDO), a catabolizing enzyme of tryptophan, is supposed to play a role in tumor immune escape. Its expression in solid tumors has not yet been well elucidated: IDO can be expressed by the tumor cells themselves, or by ill-defined infiltrating cells, possibly depending on tumor type. We have investigated IDO expression in 25 cases of non-small cell lung cancer (NSCLC). Using histochemistry and immunohistochemistry, we found that IDO was expressed not by tumor cells, but by normal cells infiltrating the peritumoral stroma. These cells were neither macrophages nor dendritic cells, and were identified as eosinophil granulocytes. The amount of IDO-positive eosinophils varied in different cases, ranging from a few cells to more than 50 per field at x200 magnification. IDO protein in NSCLC was enzymatically active. Therefore, at least in NSCLC cases displaying a large amount of these cells in the inflammatory infiltrate, IDO-positive eosinophils could exert an effective immunosuppressive action. On analyzing the 17 patients with adequate follow-up, a significant relationship was found between the amount of IDO-positive infiltrate and overall survival. This finding suggests that the degree of IDO-positive infiltrate could be a prognostic marker in NSCLC.

CD48 is a glycosyl phosphatidylinositol anchor protein known to be virtually expressed by all human leukocytes. Its ligand, 2B4, is a signaling lymphocyte activation molecule-related receptor involved in NK cell activation. Because dendritic cells (DCs) are strong inducers of NK cell functions, we analyzed the expression of CD48 in different human DC subsets. We observed that monocytes differentiating in DCs promptly down-regulate CD48. Similarly, DCs isolated from inflamed lymph nodes generally do not express CD48. Plasmocytoid DCs do not express CD48 either, whereas myeloid DCs harbored in blood, bone marrow, and thymus express it. In addition, we showed that CD48 expression in DCs affects NK cell functions during NK/DC cross-talk, because NK cells obtained from normal donors and from X-linked lymphoproliferative disease patients are, respectively, triggered or inhibited by DCs expressing surface CD48. Remarkably, IFN-gamma production by lymph node NK cells, in contrast to blood NK cells, can be negatively modulated by 2B4/CD48 interactions, indicating a 2B4 inhibitory pathway in lymph node NK cells. Therefore, the CD48 deficiency of DCs harbored in inflamed lymph nodes that we report in this study might be relevant to successfully activate lymph node NK cells in the early phase of the immune response. Our results show that distinct subsets of human DCs, differently from all other mononuclear hemopoietic cells, specifically do not express CD48. Moreover, the expression of CD48 depends on the anatomic location of DCs and might be related to the tissue-specific 2B4 function (activating or inhibitory) of the NK cells with which they interact.

CD48 is a glycosyl phosphatidylinositol anchor protein known to be virtually expressed by all human leukocytes. Its ligand, 2B4, is a signaling lymphocyte activation molecule-related receptor involved in NK cell activation. Because dendritic cells (DCs) are strong inducers of NK cell functions, we analyzed the expression of CD48 in different human DC subsets. We observed that monocytes differentiating in DCs promptly down-regulate CD48. Similarly, DCs isolated from inflamed lymph nodes generally do not express CD48. Plasmocytoid DCs do not express CD48 either, whereas myeloid DCs harbored in blood, bone marrow, and thymus express it. In addition, we showed that CD48 expression in DCs affects NK cell functions during NK/DC cross-talk, because NK cells obtained from normal donors and from X-linked lymphoproliferative disease patients are, respectively, triggered or inhibited by DCs expressing surface CD48. Remarkably, IFN-γ production by lymph node NK cells, in contrast to blood NK cells, can be negatively modulated by 2B4/CD48 interactions, indicating a 2B4 inhibitory pathway in lymph node NK cells. Therefore, the CD48 deficiency of DCs harbored in inflamed lymph nodes that we report in this study might be relevant to successfully activate lymph node NK cells in the early phase of the immune response. Our results show that distinct subsets of human DCs, differently from all other mononuclear hemopoietic cells, specifically do not express CD48. Moreover, the expression of CD48 depends on the anatomic location of DCs and might be related to the tissue-specific 2B4 function (activating or inhibitory) of the NK cells with which they interact.

Natural killer cells are important cytolytic cells in innate immunity. We have characterized human NK cells of spleen, lymph nodes, and tonsils. More than 95% of peripheral blood and 85% of spleen NK cells are CD56(dim)CD16(+) and express perforin, the natural cytotoxicity receptors (NCRs) NKp30 and NKp46, as well as in part killer cell Ig-like receptors (KIRs). In contrast, NK cells in lymph nodes have mainly a CD56(bright)CD16(-) phenotype and lack perforin. In addition, they lack KIRs and all NCR expression, except low levels of NKp46. The NK cells of tonsils also lack perforin, KIRs, NKp30, and CD16, but partially express NKp44 and NKp46. Upon IL-2 stimulation, however, lymph node and tonsilar NK cells up-regulate NCRs, express perforin, and acquire cytolytic activity for NK-sensitive target cells. In addition, they express CD16 and KIRs upon IL-2 activation, and therefore display a phenotype similar to peripheral blood NK cells. We hypothesize that IL-2 can mobilize the NK cells of secondary lymphoid tissues to mediate natural killing during immune responses. Because lymph nodes harbor 40% and peripheral blood only 2% of all lymphocytes in humans, this newly characterized perforin(-) NK cell compartment in lymph nodes and related tissues probably outnumbers perforin(+) NK cells. These results also suggest secondary lymphoid organs as a possible site of NK cell differentiation and self-tolerance acquisition.

NK and DC reciprocal interactions have only recently been investigated. In this study, we focused on the interplay between NK cells and DC in two models of bacterial infection. Immature monocyte-derived DC were cultured in the presence of live Escherichia coli or bacillus Calmette-Guerin. Upon exposure to either extracellular or intracellular bacteria, DC underwent maturation as assessed by the increased levels of expression of CD80, CID86, and HLA molecules and the de novo expression of CD83 and CCR7. Significant amounts of TNF-alpha and IL-12 were released by DC upon infection, whereas IL-2 and IL-15 were barely detectable in culture supernatants. Both infected and uninfected DC were capable of inducing in fresh autologous NK cells the expression of CD69 and HLA-DR and of inducing cell proliferation. Remarkably, however, infected DC were much stronger inducers of NK cell activation and proliferation than uninfected DC. Thus, after just 24 h of NK/DC coculture, only those NK cells that had been exposed to bacteria-infected DC had acquired the ability to lyse autologous immature DC. In addition, infected DC were more resistant to NK-mediated lysis as a consequence of the up-regulation of HLA class I molecule expression on their surface. This study suggests a regulatory circuit involving NK cells and DC in which DC-induced NK cell activation is effectively enhanced by the presence of pathogens. Activated NK cells, by limiting the supply of immature DC, may then exert a control on subsequent innate and adaptive immune responses.

Treatment of melanoma cell lines with IFN-gamma induces the switch from proteasome (PS) to immunoproteasome (iPS). This finding has profound implications for the immunobiology of melanoma cells since certain peptides (such as Melan-A(mart1)(27-35)) are cleaved differently by iPS, thus implying a different ability to be presented by HLA class I molecules. IFN-alpha is a cytokine not only produced during infectious diseases, but also used in the treatment of certain cancers. Nevertheless, the effects of IFN-alpha on the switch of PS to iPS are largely unknown. A comparison of the effect of both IFN-alpha and IFN-gamma was thus carried out on melanoma cell lines. RT-PCR showed that mRNA for iPS subunits (i.e. LMP-2, LMP-7 and MECL-1) was detectable both in untreated and IFN-treated melanoma cells. Immunoblotting analysis revealed that while IFN-gamma was able to consistently induce the switch from PS to iPS, IFN-alpha treatment did not, possibly due to post-transcriptional event(s) blocking the expression of iPS-specific subunits. Finally, Melan-A(mart1)(27-35) peptide was found only in the HPLC-MS spectra from both untreated and IFN-alpha-treated cells, but not upon IFN-gamma treatment. Altogether, these data demonstrate that IFN-alpha does not induce the switch from PS to iPS.

Bacillus Calmette-Guerin (BCG) is currently employed in the treatment of superficial bladder cancer but, despite its recognized effectiveness in preventing recurrences and progression, the immune mechanisms behind its antitumor activity remain to be delineated. In this study we provide evidence that a prolonged increase in the plasma levels of IL-2, but not IL-1β, IL-4, IL-10, IL-2R or TNF-α occured in patients affected by bladder cancer following effective BCG treatment. Conversely, a drop in circulating IL-2 was consistently associated with tumor relapse. The level of IL-2 was elevated even further 15 days after the last BCG administration in patients who did not experience tumor recurrence, suggesting a prolonged T cell-mediated response against antigens other than BCG. Our results indicate that a specific type 1 immune response plays a major role in the anti-cancer activity of BCG. In addition, monitoring IL-2 plasma levels may offer a useful tool for predicting tumor recurrences.

Dendritic cells (DC) play a pivotal role in the initiation, maintenance and regulation of the immune response. Here we obtained the first evidence that DC, in the absence of any foreign antigens, induce the expression of B7 family costimulatory molecules, such as CD80, CD86, B7-H1, PD-L2, B7-H3, and B7RP-1, on autologous T lymphocytes. Cell-to-cell contact between DC and T cells was needed in order to obtain this expression on T cells. De novo expressed B7 molecules on T cells were functional since B7(+) T cells were able to costimulate the proliferation of highly purified T cells. While both autologous and allogeneic DC were able to induce similar levels of costimulatory molecule expression, the chemokine receptor repertoire on B7(+) T cells after interaction with DC varied depending on the presence of alloantigens during the interaction (CCR7(-), CCR5(+)) or the absence of antigens (CCR7(+), CCR5(-)). In accordance with this different pattern of chemokine receptors in the two conditions, we propose that, after the encounter with DC in lymphoid organs, this peculiar T cell population should reside in the T cell areas of the lymph nodes or migrate to peripheral sites of inflammation, providing a second signal for activating or switching off, respectively, naive or peripheral effector T cells.

In HIV-1–infected adults, eosinophilia, increased eosinophil cationic protein (ECP), and elevated serum total IgE levels have been observed. 1Paganelli R Scala E Mezzaroma I Pinter E D’Offizi G Fanales-Belasio E et al.Immunologic aspects of hyperimmunoglobulinemia E-like syndrome in patients with AIDS.J Allergy Clin Immunol. 1995; 95: 995-1003Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar There is little data with respect to these factors in children. Our previous study showed a relationship between elevated serum total IgE level and HIV-1 disease progression in pediatric patients. 2Viganò A Principi N Crupi L Onorato J Zuccotti GV Salvaggio A. Elevation of IgE in HIV-infected children and its correlation with the progression of disease.J Allergy Clin Immunol. 1995; 95: 627-632Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar The objective of the present study was to define whether eosinophil involvement together with IgE elevation could be identified in HIV-1–infected children. The study group consisted of 38 vertically HIV-1–infected subjects (median age, 6.5 years; range, 1 to 13 years; 15 boys), 15 of whom had acute respiratory infections (ARIs) at enrollment. The diagnosis of HIV-1 infection and the clinical and immunologic status of children met the criteria of the 1994 Centers for Disease Control (CDC) HIV classification for children. 3Centers for Disease Control Classification system for human immunodeficiency virus (HIV) infection in children under 13 years of age.MMWR Morb Mortal Weekly Rep. 1994; 43: 1-10Google Scholar As regards clinical classification, 26 subjects were in classes N, A, or B (19 without ARIs and 7 with ARIs), whereas 12 were in class C (4 without ARIs and 8 with ARIs); as regards immunologic classification, 24 children were in classes 1 and 2 (18 without ARIs and 6 with ARIs), whereas 14 were in class 3 (5 without ARIs and 9 with ARIs). None of the class N patients was receiving antiretroviral therapy; patients in classes A and B were being treated with zidovudine, whereas patients in class C were taking zidovudine and didanosine. 4Pizzo PA Wilfert C. Antiretroviral therapy for infection due to human immunodeficiency virus in children.Clin Infect Dis. 1994; 19: 177-196Crossref PubMed Scopus (20) Google Scholar When needed, patients were receiving specific prophylaxis for opportunistic infections in agreement with published guidelines. 4Pizzo PA Wilfert C. Antiretroviral therapy for infection due to human immunodeficiency virus in children.Clin Infect Dis. 1994; 19: 177-196Crossref PubMed Scopus (20) Google Scholar According to the definition of Kline et al, 5Kline MW Paul ME Bohannon B Kozinetz CA Shearer WT. Characteristics of children surviving to 5 years of age or older with vertically acquired HIV infection.Pediatr AIDS HIV Infect: Fetus Adolesc. 1995; 6: 350-353PubMed Google Scholar among our HIV-1–infected children, 12 subjects had rapidly progressing disease (4 without ARIs and 8 with ARIs), whereas 26 patients had nonrapidly progressing disease (19 without ARIs and 7 with ARIs). As control subjects, 70 HIV-1–negative children (median age, 5.5 years; range, 1 to 13 years; 28 boys), 26 of whom had ARIs at enrollment, were studied. To avoid the possible increase of eosinophil counts, serum ECP, and IgE concentrations caused by allergic activation, in both HIV-1–infected children and control subjects eligibility criteria included a negative personal and family history of atopy. Each child was concomitantly evaluated for whole blood cell count by means of an automated hematology analyzer (Coulter Electronics, Inc, Miami Lakes, Fla), serum ECP concentrations by means of an RIA (Pharmacia ECP RIA, Pharmacia, Uppsala, Sweden), total serum IgE by immunocapture (Pharmacia CAP System IgE RIA, Pharmacia), allergy to common airborne and food allergens by means of skin prick tests, and individual and family history of atopy by means of a medical history. The diagnosis of ARI (both bacterial and viral) was based on clinical findings, radiologic data, and microbiologic isolation of pathogens, according to standardized conventional methods. A diagnosis of pneumonia was made in 8 HIV-1–infected children and 7 control subjects, rhinosinusitis in 3 HIV-1–infected children and 8 control subjects, acute tracheobronchitis in 2 HIV-1–infected children and 8 control subjects, and acute otitis media in 2 HIV-1–infected children and 3 control subjects. Informed consent was obtained from the parents or legal guardians of all the children. Comparison between groups were performed with the Mann-Whitney U test. In both HIV-1–infected children and control subjects, none of the subjects had a positive family history of atopy, none had allergy since birth, and none had positive skin prick test responses. Table I summarizes eosinophil counts, serum ECP concentrations, and serum IgE levels in the study population. Table IEosinophil counts, serum ECP concentrations, and serum IgE levels in the study populationLaboratory parametersNo ARIARIHIV-1–infected subjects (n = 23)Control subjects (n = 44)HIV-1–infected subjects (n = 15)Control subjects (n = 26)Eosinophil counts (cells/μL) Median130160190180 Range25-330110-27552-50091-492Serum ECP (μg/L) Median9 *12 †2020 Range4-209-1313-3414-41Serum IgE (KU/L) Median58 ‡19166 §29 Range2-18111-2817-200015-40* P < .0001 versus HIV-1–infected children with ARIs † P = .0002 versus control subjects with ARIs. ‡ P = .03 versus control subjects without ARIs § P = .02 versus control subjects with ARIs. Open table in a new tab Eosinophil counts and serum ECP concentrations showed no significant differences between HIV-1–infected children and control subjects either with or without ARIs, whereas IgE levels were significantly increased in HIV-1–infected children. Independent from HIV-1 status, ECP concentrations were significantly higher in patients and control subjects with ARIs in comparison to those without ARIs, whereas eosinophil counts and IgE levels showed no significant differences in the presence or absence of ARIs. Table II describes the relationship between laboratory parameters and CDC setting in HIV-1–infected children. Table IILaboratory parameters and CDC setting in HIV-1–infected childrenCDC settingCDC clinical classesCDC immunologic classesN+A+B (n = 26)C (n = 12)P value1+2 (n = 24)3 (n = 14)P valueEosinophil counts (cells/μL) Median158141.42130142.55 Range46-50025-29046-38025-500Serum ECP (μg/L) Median1420.061119.02 Range4-306-344-306-27Serum IgE (KU/L) Median64197.0229296.02 Range2-147715-20002-14776-2000 Open table in a new tab With respect to clinical setting, patients in clinical class C showed higher, even if not significantly increased, levels of serum ECP and significantly increased concentrations of serum IgE than subjects in clinical classes N, A, and B. On the contrary, eosinophil counts were similar between children in clinical class C and those in clinical classes N, A, and B. With respect to the degree of immunodeficiency, patients in immunologic class 3 showed a significant increase of both serum ECP and IgE concentrations than subjects in immunologic classes 1 and 2. On the contrary, eosinophil counts were similar between children in immunologic class 3 and those in immunologic classes 1 and 2. Table III shows the relationship between laboratory parameters and HIV-1 disease progression. Table IIILaboratory parameters and HIV-1 disease progressionLaboratory parametersHIV-1 disease progressionRapid progression (n = 12)Nonrapid progression (n = 26)P valueEosinophil counts(cells/μL) Median166137.27 Range25-50046-360Serum ECP (μg/L) Median209.0002 Range14-344-30Serum IgE (KU/L) Median31643.004 Range26-20002-545 Open table in a new tab Interestingly, serum ECP and IgE concentrations were significantly higher in subjects with rapidly progressing disease than in those with nonrapidly progressing disease, whereas no significant difference was observed in eosinophil counts between the 2 groups of children. Our findings show that eosinophilia is not a feature of HIV-1–infected children, even in the presence of increased serum ECP and IgE concentrations. There are discordant data on eosinophil involvement in HIV-1–infected patients. In adults an increase of eosinophil counts in peripheral blood during HIV-1 infection has been shown. 1Paganelli R Scala E Mezzaroma I Pinter E D’Offizi G Fanales-Belasio E et al.Immunologic aspects of hyperimmunoglobulinemia E-like syndrome in patients with AIDS.J Allergy Clin Immunol. 1995; 95: 995-1003Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar In HIV-1–infected children, Bacot et al, 6Bacot BK Paul ME Navarro M Abramson SL Kline MW Hanson IC et al.Objective measures of allergic disease in children with human immunodeficiency virus infection.J Allergy Clin Immunol. 1997; 100: 707-711Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar in agreement with our results, failed to show a significant increase in eosinophil counts. As regards ECP, increased levels of this protein in both atopic and nonatopic HIV-1–infected adults either in the presence or absence of eosinophilia have been described. 1Paganelli R Scala E Mezzaroma I Pinter E D’Offizi G Fanales-Belasio E et al.Immunologic aspects of hyperimmunoglobulinemia E-like syndrome in patients with AIDS.J Allergy Clin Immunol. 1995; 95: 995-1003Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar To our knowledge, this is the first report on the measurement of serum ECP in HIV-1–infected children. In our study serum ECP concentrations seem to be increased in children with ARIs independent of HIV-1 status and in HIV-1 infected children in clinical class C, in immunologic class 3, and with rapid progression of the disease. However, because of the high incidence of ARIs in our children with severe HIV-1 disease, we cannot finally establish whether the increase in serum ECP level is only a consequence of ARI or also represents a marker of HIV-1 disease progression. Further studies are necessary to clarify the significance of these data. Findings regarding IgE levels confirm our previous study in which elevated serum total IgE concentrations appeared as evidence of the immunologic abnormalities caused by HIV-1 infection in pediatric patients. 2Viganò A Principi N Crupi L Onorato J Zuccotti GV Salvaggio A. Elevation of IgE in HIV-infected children and its correlation with the progression of disease.J Allergy Clin Immunol. 1995; 95: 627-632Abstract Full Text Full Text PDF PubMed Scopus (88) Google Scholar In conclusion, HIV-1 infection does not seem to produce eosinophilia in children at baseline and with ARIs. On the contrary, eosinophil activation appears to be related to ARI and may also be associated with severe HIV-1 disease; moreover, serum IgE levels are increased in children with HIV-1 disease progression.

We assessed the long-term feasibility, safety, and tolerability of two regimens of aerosolized pentamidine (AP) as primary prophylaxis of Pneumocystis carinii pneumonia (PCP) in a large sample of infants and children with symptomatic HIV infection in 21 pediatric departments. One hundred forty children were assigned to receive 60 mg every 2 weeks (n = 60) or 120 mg every 4 weeks (n = 80) of AP, delivered by the ultrasonic nebulizer Fisoneb under the supervision of trained personnel. Children underwent monthly clinical and laboratory controls for toxicity and/or development of PCP for an 18-month period. Baseline characteristics were similar in the two treatment groups. The median age was 5 years. The feasibility of administering AP was excellent in 84 (60%) and good in 38 (27%) children, All children aged <2 years showed excellent or good feasibility. Long-term compliance was good with both regimens. No child had severe adverse reactions requiring discontinuation of the treatment. Cough, sneezing, and bronchospasm were the most frequent side effects occurring, respectively, in 12, 3.7, and 0.7% of the 60-mg treatments and in 19.1, 6.1, and 2.8% of 120-mg treatments (p < 0.05). Their incidence was not different in children younger or older than 5 years. Two episodes of PCP were observed in the group receiving 120 mg monthly, whereas none of the 60 children in the biweekly schedule had PCP (p = 0.20), AP can be safely administered to very young children with few adverse effects.

We evaluate correlations among airway resistance measured by the interrupter method with a new device (Microlab 4000, Micromedical) with those of standard pletismography. Twenty-two healthy children (mean age 10 +/- 3 yrs) without any remote or recent history of lung disease were enrolled in this study. All baseline values of lung function were within normal limits confirming health conditions. A highly significant degree of linear correlation was found between inspiratory (Rint-i) resistance of the interrupter method and all the pletismographic measurments (Raw-i r = 0.74, Raw-e r = 0.82, Raw-t r = 0,81, s-Gaw r = 0,73) and to a lesser extent with flows (FEV1 r = 0,61, FEF50 r = 0,73). A similar correlation was found with reciprocal of Rint, Gint-i except for FEV1; in contrast no statistical correlations were found between expiratory resistance (Rint-e) and pletismographic parameters except for Raw-i (r = 0,64); on the contrary Gint-e shows significant correlations with all parameters measured except for s-Gaw.These results,obtained in normal healthy well collaborating children, allow us to conclude that eventhough more and larger studies are necessary to better standardize the interrupter technique, this new device is able to bring new informations about the lung function in children.

Serum level of pro-inflammatory cellular markers such as eosinophil cationic protein (s-ECP), neutrophil myeloperoxidase (s-MPO) and mast cell tryptase (s-TRI) have been analysed in a group of 80 children who were subdivided in 3 subgroups according to the underline pathology: a) allergic asthma, b) infective wheezing, c) atopic dermatitis or eczema. These children were compared with an adeguate sex-, age mathched group of normale controls. Each patient was further assigned to symptomatica (S) or asymptomatic (As) subgroups on the basis of the presence or absence of specific acute symptoms. At entry, illness severity was accurately assessed to correlate clinical status with the markers serum levels. s-ECP has been found elevated in all the symtomatic groups unregardless of the type of disease (asthma, wheezing or atopic dermatitis) and of the etiology (allergic asthma or infective wheezing) (s-ECP: mu g/L allergic asthma S = 43 +/- 34; AS = 22 +/- 12; C = 8 +/- 3; S vs As p < 0.05; S vs C p < 0.0005; As vs C NS; infective wheezing S = 28 +/- 13, As = 17 +/- 12, C = 10 +/- 3, S vs As p < 0.01, As vs C NS, atopic dermatitis S = 49 +/- 13, As = 20 +/- 11, C = 10 +/- 3, S vs As p < 0.01, S vs C p < 0.002, As vs C NS). s-MPO has been found statistically significant only in acute wheezing and acute atopic dermatitis vs normal controls, whereas no statistically differences has been found in allergic asthma (s-MPO mu g/l: allergic asthma S = 1180 +/- 448; As = 841 +/- 500; C = 596 +/- 217; S vs As NS; S vs CNS; As vs CNS; infective wheezing S = 1142 +/- 385; As = 1386 +/- 364; C = 665 +/- 384; S vs As NS; S vs C p < 0.005; As vs C p < 0.01; atopic dermatitis S = 1474 +/- 292; As = 1011 +/- 604; C = 665 +/- 384; S vs As NS; S vs C p < 0.005; As vs C NS); those results on one side confirm the role of neutrophils during infections even viral one's, but on the other side demonstrate a lesser involvement in allergic diseases. s-Tryptase was always found at lower levels of the capacity detenction of the test in all situations analysed; this surprisingly result confirm same other data present in literature. In conclusion our results confirm the usefulness, at least for s-ECP and s-MPO, as pro-inflammatory activity markers well correlated with disease activity; nevertheless, our data that at least for s-ECP a not specific rise according to etiology (allergy or infection). s-MPO seems more reliable as an activity marker of infective processes than allergic one's More data are necessary to better define the role of neutrophils in allergic diseases. Data about s-TRY from our study didn't allow us to consider it as a reliable marker of allergic disease activity. Therefore more data on larger number of patients are needed to better define the role and usefulness of these markers both in allergic and infectious diseases.