The immunity of upper airways.

A specialized immune system, called the nasopharynx-associated lymphoid tissue (NALT), is located on the mucosal surface of upper airways and is composed of both innate and specific immunity elements, closely related to each other and to the systemic defence, and spread over the nasopharynx, the nose and the middle ear. The NALT has a major role as regards to the infectious diseases of this area, which are the most common in children. It is also an interesting field of experimentation for new vaccine strategies in the future.

Allergen specific nasal challenge to latex in children with latex allergy: clinical and immunological evaluation.

There are no data concerning the significance of allergen specific nasal challenge to latex (ASNCL) in the pediatric population and the effect of mometasone furoate nasal spray (MFNS), topic corticosteroid exerting a potent anti-inflammatory activity in children with latex allergic rhinitis. The aims of this study are: to investigate the clinical and immune pathological effects of ASNCL in children with latex allergy; to study the effects of MFNS pre-medication on the clinical and immune pathological effects of ASNCL in children with latex allergy. Thirteen children: 6 male and 7 female, mean (SD) age 9.6 (2.9) years, with latex allergy and seven children: 3 male and 4 female, mean (SD) age 9.9 (3.8) years, without latex allergy underwent ASNCL. Nasal symptoms were recorded, nasal lavage fluid was collected to measure tryptase, eosinophil cationic protein (ECP), interleukin-5, interferon-gamma levels, and spirometric test was performed for each patient without or with premedication with MFNS. ASNCL induced a clinical allergic response and increased tryptase levels only in children with latex allergy. No serious adverse events occurred after ASNCL. MFNS premedication reduced both tryptase and ECP levels only in children with latex allergy. ASNCL is a simple, reliable and useful tool to make or confirm the diagnosis of nasal symptoms due to latex; it allows us to study both clinical symptoms and local immunological changes. MFNS premedication before an ASNCL may prevent some immunological responses induced by ASNCL without clinical allergic modifications.

Urticaria and urticaria related skin condition/disease in children.

Urticaria is a rash, that typically involves skin and mucosa, and is characterized by lesions known as hives or wheals. In some cases there is an involvement of deep dermis and subcutaneous tissue that causes a skin/mucosa manifestation called angioedema. Urticaria and angioedema are very often associated: urticaria-angioedema syndrome. The acute episodic form is the most prevalent in the pediatric population, and it is often a recurrent phenomenon (recurrent urticaria). Acute episodic urticaria it is usually triggered by viruses, allergic reactions to foods and drugs, contact with chemicals and irritants, or physical stimuli. In many instances it is not possible to identify a specific cause (idiopathic urticaria). Chronic urticaria is a condition that can be very disambling when severe. In children is caused by physical factors in 5-10% of cases. Other trigger factors are infections, foods, additives, aeroallergens and drugs. The causative factor for chronic urticaria is identified in about 20% of cases. About one-third of children with chronic urticaria have circulating functional autoantibodies against the high affinity IgE receptor or against IgE. (chronic urticaria with autoantibodies or "autoimmune" urticaria). It is not known why such antibodies are produced, or if the presence of these antibodies alter the course of the disease or influence the response to treatment. Urticaria and angioedema can be symptoms of systemic diseases (collagenopathies, endocrinopathies, tumors, hemolytic diseases, celiachia) or can be congenital (cold induced familiar urticaria, hereditary angioedema). The diagnosis is based on patient personal history and it is very important to spend time documenting this in detail. Different urticaria clinical features must guide the diagnostic work-up and there is no need to use the same blood tests for all cases of urticaria. The urticaria treatment includes identification of the triggering agent and its removal, reduction of aspecific factors that may contribute to the urticaria or can increase the itch, and use of anti-H1 antihistamines (and/or steroids for short periods if antihistamines are not effective). In some instances an anti-H2 antihistamine can be added to the anti-H1 antihistamines, even if the benefits of such practice are not clear. The antileucotriens can be beneficial in a small subgroup of patients with chronic urticaria. In case of chronic urticaria resistant to all the aforementioned treatments, cyclosporine and tacrolimus have been used with good success. When urticaria is associated to anaphylaxis, i.m epinephrine needs to be used, together with antihistamines and steroids (in addition to fluids and bronchodilatators if required).

Diagnostic value of three different latex extracts.

The diagnosis of latex allergy is made on clinical history, but a confirmatory skin prick test (SPT) or a serological assay based on a commercial latex extract is always recommendable. Different raw materials can be used in the preparation of commercial latex extracts. Such extracts can consequently show both different qualitative profiles and a different diagnostic potential. Therefore, the selection of a proper latex extract is essential for in vitro and in vivo diagnosis of latex allergy. In the present study three different latex extracts, prepared from different raw materials (ammoniated -AL-, serum -SL-, or rubber particles -RPE- latex), are compared by in vitro techniques using sera from twenty patients with latex allergy. SDS-PAGE technique was used to compare the antigenic profile of the three latex extracts. Subsequently, their allergenic profiles were evaluated by immunoblotting technique using the individual sera from the twenty latex allergic patients. The diagnostic potential of the three latex extracts was also evaluated using direct Radio-Allergo-Sorbent Test (RAST) as well as skin prick tests (SPTs). In order to establish the more appropriate latex extract in a perspective of in vivo diagnosis of latex sensitization, the same latex extracts were subsequently compared by an in vivo SPT involving ten of the above subjects. The SDS-PAGE profiles of the three latex extracts examined were quite different. SL extract showed numerous bands comprised between 10-100 kDa. RPE extract was characterized by two intense bands at 14 and 20 kDa while AL extract showed the poorer antigenic composition. Analogously, immunoblotting analysis evidenced a different profile in relation to both different patients and extracts. For only two out of the twenty sera, direct RAST results showed a same positive class in relation to the different latex extracts used. SPT with SL extract showed, in respect to the other extracts (AL, RPE), a significantly higher wheal. This study showed that SL extract is able to express the best in vitro and in vivo diagnostic potential. Thus, its use should be preferred for the diagnosis of patients affected by latex allergy.

Eyelash length in children with vernal keratoconjunctivitis: effect of treatment with cyclosporine eye drops.

The upper eyelashes in vernal keratoconjunctivitis (VKC) patients have been reported to be longer than in healthy age- and gender-matched subjects. Eyelash length positively correlated to the severity of the disease and negatively to the employment of cyclosporine eye drops, suggesting that specific humoral factors could be involved in both ocular inflammation and elongation of the eyelashes. The aim of the present study is to evaluate a possible relationship between eyelash length and the duration of topical cyclosporine treatment. The length of the upper eyelashes of 34 VKC patients never treated with topical cyclosporine (Cyc-NT) was matched with that of 58 VKC patients treated with cyclosporine (Cyc-T). The latter group was divided into three subgroups, depending on the duration of therapy: 1-6 months (group 1; 21 subjects) , 7-12 months (group 2; 19 subjects), greater than 12 months (group 3; 19 subjects). Cyc-NT patients eyelashes were significantly longer than those of VKC patients treated for 1-6 months (group 1). No significant difference was found between Cyc-NT and Cyc-T patients in group 2 and group 3. The differences between Cyc-T patients and group 1 and 2, group 2 and 3, and group 1 and 3 were not statistically significant. The eyelash shortening observed seems directly related to the rapid improvement of ocular symptoms induced by the treatment. A receptor down-regulation by mediators of ocular inflammation may explain this data, although different cytokines, hormones or other humoral mediators could be expressed on the ocular surface at different stages of the disease, mainly in periods of rapid change of the clinical course.

High intracytoplasmatic levels of Il-4 and Il-5 in a patient with Gleichs syndrome: case report.

Gleichs syndrome is characterized by recurrent localized angioedema, hypereosinophilia, elevated levels of IgM, rapid weight gain, itchy urticaria and fever. Little is known about the pathogenesis of this disease. Increased serum levels for IL5, IL6 and C5a have been reported before and during clinical exacerbations. In order to better understand the role of the T cells in Gleichs syndrome we analyzed the intracellular cytokine expression in CD3+ cells of a patient affected by the disease. As hypereosinophilia was documented, we asked whether IL-4 and IL-5 levels were increased, and the intracytoplasmatic expression of these Th2-cytokines was determined. The percentage of T lymphocytes (CD3-gated cells) of both CD8- and CD8+ phenotype expressing different cytokines showed an unusually high percentage of Th2-related cytokine (IL-4, IL-5 and IL-13) expressing T lymphocytes. The two new variants (myeloproliferative and lymphoproliferative) seem to account for hypereosinophilia in patients with hypereosinophilic syndrome (HES). In the lymphroliferative variant, the presence of a clonal CD3-CD4+ Th2 like lymphocyte secreting IL-4 and IL-5 in peripheral blood, may explain the hypereosinophilia and the hyper-IgE. In our study we show that the patient had a lymphoproliferative variant and her T cell had a Th2 type phenotype. Moreover, we suggest that Th2 lymphocytes may play a role in the pathogenesis of Gleichs syndrome. Further studies are needed to evaluate the possibility that a polyclonal aspecific activation of Th2 type cells can lead to hypereosinophilia, IgE production and the other manifestations typical of Gleichs syndrome.

Biphasic anaphylactic reaction to Ketorolac tromethamine.

Ketorolac tromethamine is a recent injectable non-steroidal anti-inflammatory drug (NSAID) with analgesic properties approved for short-term pain management. In spite of its increasing use both in adults and children, relatively few allergic-like reactions have been reported. Reactions are often severe, and a death occurred following an intramuscular injection of ketorolac.

Cross-reactivity between IgE-binding proteins from Anisakis simplex and Dermatophagoides pteronyssinus.

An association was found between Anisakis simplex (As) and Dermatophagoides pteronyssinus (Dp) sensitization. One recent study shows a cross-reactivity between As and Dp and tropomyosin (tr)is suspected as being one of the proteins responsible of this cross-reaction. The aim of our study was: 1) to confirm the cross-reactivity between Dp and As; 2) to determine the importance of tr in this cross reaction. SDS-PAGE analysis of Dp and As (metabolic and somatic) extracts was carried out. Then an IgE immunoblotting test using serum from a patient who had specific IgE only to Dp and As and immunoblotting inhibition experiments using Dp extract and tr as inhibitors were performed. We found that patients serum reacted: 1) against larval As antigens with a molecular weight (mw) of 25 kilodalton (kD) and a mw > than 100 kD, 2) against various metabolic As antigens with a mw > than 100 kD, a mw ranging approximately from 35 to 50 kD, and a mw around 20 kD, and 3) against Dp proteins with mw between 35 and 55 kD. Preincubation of patient's serum with Dp extract caused the disappearance of reactivity against antigens with a mw > than 100 kD in both larval and metabolic As extracts and against proteins with mw ranging approximately from 35 to 50 kD in the metabolic As extract. Preincubation of patients serum with As extract caused the disappearance of reactivity against antigens with mw between 35 and 55 kD in the Dp extract. Pre-incubation of patients serum with tr did not induce any change in the immunoblotting profile. The results show that 1) cross-reactive components between Dp and As are some proteins with a mw ranging approximately from 35 to 50 kD and with a mw > than 100 kD, and 2) tr is not involved in cross-reactivity between As and Dp.

Onset of clinical signs in children with HIV-1 perinatal infection. Italian Register for HIV Infection in Children.

OBJECTIVE: To investigate the timing of onset of each clinical sign in infants and children with HIV-1 perinatal infection. DESIGN AND METHODS: A total of 200 HIV-1-infected children followed-up from birth were studied. Failure and conditional probabilities were estimated by the Kaplan-Meier product-limit method. Cox proportional hazard analysis was used to evaluate independently associated factors. Results of 934 seroreverters were used to calculate reference values of CD4+ cell counts and predictivity of early signs. RESULTS: Median age at the onset of any sign was 5.2 months (range, 0.03-56 months). The probability of remaining asymptomatic was 19% [95% confidence interval (CI), 14-25.1] at 12 months and 6.1% (95% CI, 2.6-11.7) at 5 years. Lymphadenopathy (69.5%), splenomegaly (62.4%) and hepatomegaly (58.4%) were the most common signs in the first year of life. Peculiar to the first year of life (compared with subsequent ages) was the onset of primary HIV-1 hepatitis and diarrhoea (rate ratios, 23.3 and 15.2, respectively). When CD4+ cell counts in the asymptomatic stage (age, 2 months; range, 0.03-5.9 months) were below rather than above the fifth percentile in seroreverters, onset of signs was earlier [3 range, 0.03-19) versus 5 (range, 0.03-56) months]. Children manifesting signs before the 5.2-month breakpoint had a lower survival rate [74% (range, 65.9-82%) at 12 months and 45% (range, 32.9-57%) at 5 years] than children manifesting signs later [98% (range, 92.2-100%) at 12 months and 74% (range, 60.3-87.7%) at 5 years]. Children whose birthweight was < or = 2400 g had an earlier onset (24 months; range, 1-57 months) of severe conditions than children with higher birthweight (71 months; range, 1-71 months). Development of lymphadenopathy or hepatosplenomegaly within 3 months of life were reliable indicators of infection. CONCLUSIONS: This study describes the sequence of onset of signs in perinatal HIV-1 infection. Infection is shown to progress faster than in adults and in a different manner. Low birthweight, early decreased CD4+ cell counts, and early onset of signs are predictive of rapid progression.

VIP restores natural killer cell activity depressed by hepatitis B surface antigen.

Vasoactive intestinal peptide (VIP) has recently been shown to bind to human lymphocytes and modulate immune functions. The ability of VIP in restoring natural killer (NK) cell activity depressed by hepatitis B surface antigen (HBsAg) has been investigated in the present research. Human lymphocytes were incubated with HBsAg and, after washing, a 4-hr cytotoxicity assay was performed. VIP was coincubated with lymphocytes during the preincubation with HBsAg or, alternatively, throughout the cytotoxicity assay. The study revealed that VIP, either preincubated or coincubated in the 4-hr assay, strongly restores NK cell activity depressed by viral antigen. This is noteworthy considering that a number of lymphocyte modulators such as interferons fail in restoring viral-dependent NK cell activity depression. In contrast with previous reports, even when coincubated in the 4-hr assay, VIP is a strong activator of NK cell activity. Further studies will be required to understand which mechanisms are involved in the interrelation between VIP and NK cells during viral infections.

Inhibition of natural killer cell cytotoxicity and interferon gamma production by the envelope protein of HIV and prevention by vasoactive intestinal peptide.

Natural killer (NK) cell dysfunction is common in human immunodeficiency virus (HIV)-infected subjects, although its mechanisms are poorly understood. A direct effect of HIV envelope glycoprotein gp120 may be involved. We investigated the in vitro effects of gp120 on the major NK cell effector functions, natural cytotoxicity and cytokine production. In addition, the ability of the vasoactive intestinal peptide (VIP) to modulate these effects was investigated. Our results indicated that gp120 inhibits NK natural cytotoxicity and showed, for the first time, that the inhibition affects also the production of the proinflammatory cytokine interferon-gamma (IFN-gamma). Interestingly, the inhibitory effect on NK cell functions was obtained with gp120 at concentrations within the range measured in the serum of HIV-infected subjects. Furthermore, we showed that the inhibitory activity of gp120 can be prevented by coincubation with VIP, even if VIP has no stimulatory activity by itself. Taken together these data suggest that (1) an inhibitory effect of gp120 may account for the NK cell dysfunction in HIV-infected subjects; (2) the gp120-mediated decrease in IFN-gamma production by NK cells may contribute to the cytokine imbalance observed in HIV infection; and (3) VIP counteracts the inhibitory effect of gp120 on NK cell functions.

Horizontal transmission of human immunodeficiency virus type 1 from father to child.

An unusual case of human immunodeficiency virus type 1 (HIV-1) infection in a child was studied. The child, identified as HIV-1 infected at 5 years of age, lived with his parents and a 3-year-old sister. HIV-1 infection was excluded in the mother and sister, but confirmed in the father, who was unaware of his infection and was in good health, apart from an atopic dermatitis on the face and limbs. A portion of the HIV-1 proviral envelope gene was amplified from the father's and child's peripheral blood cells, and the amplified products were cloned and sequenced. Phylogenetic analysis disclosed that the father's and child's viral sequences clustered together, and were clearly distinct from the sequence sets obtained from six epidemiologically unlinked mother-child HIV-1-infected pairs included in the analysis. HIV-1 variability was lower in the child's sequence set than in the father's, and the variability between father's and child's sequences was significantly lower than that found between epidemiologically unlinked cases (p < 0.001). An uncommon APGR motif on the tip of the V3 domain was found in both the father's and child's viral clones. These data, together with the epidemiological investigations, strongly suggest that the child acquired the infection from his father, possibly by exposure to bleeding skin lesions.

Thyroid function in children with perinatal human immunodeficiency virus type 1 infection.

OBJECTIVE: To study thyroid function in children with perinatal HIV-1 infection retrospectively and determine whether thyroid abnormalities are correlated with clinical condition, disease progression, immunological impairment, and viral load. STUDY DESIGN AND SETTING: Total (TT4) and free (FT4) thyroxine, total (TT3) and free (FT3) triiodothyronine, reverse triiodothyronine (rT3), thyrotropin (TSH), thyroglobulin (TG), and thyroid binding globulin (TBG) were measured twice in 56 children with perinatal human immunodeficiency virus type 1 (HIV-1) infection. Median age at first determination was 13.5 (range: 0.03-127.0) months; median age at second determination was 66.2 (range 3.42-147.4) months. Antithyroglobulin, antimicrosomal, thyroid peroxidase, and thyrotropin receptor antibodies were also evaluated. Fifty-three healthy children were selected as controls. RESULTS: TT3, TT4, FT4, and TG were significantly reduced and rT3, TBG, and TSH increased in children with HIV-1 infection when compared with controls. Thyroid dysfunction correlated with severe immunosuppression and high viral load early in life preceded the onset of the disease and worsened over time. Autoantibodies were negative in all children with HIV-1 infection in all determinations. CONCLUSION: Thyroid abnormalities are observed early in the course of perinatal HIV-1 infection; thyroid dysfunction is particularly pronounced in children with severe immunosuppression and high viral load. Modifications of thyroid function precede worsening of clinical course in HIV-1 infected children.

Airway resistance and spirometry in children with perinatally acquired human immunodeficiency virus-type 1 infection.

Airway resistance was measured by the interrupter technique in 54 children [aged 63.8 months (range: 9.1-131.6 months)], with perinatal human immunodeficiency virus-type 1 (HIV-1) infection and in a control group of 315 gender, height, and race-matched healthy children. In addition, 14 HIV-infected children, aged 75-131 months, had spirometry performed. Resistance was significantly higher in infected children than in controls (0.84 +/- 0.3 vs 0.64 +/- 0.08 kPa x l(-1) x s; t = 9.991; P < 0.0001). Resistance decreased with age in controls (r = -0.95; P < 0.001), but not in infected children (r= -0.22; P = 0.105). Resistance did not correlate with mothers' intravenous drug addiction, perinatal data, T-cell subset numbers, treatment, clinical course, or presence of respiratory complications. Resistance was higher (t = 3.103; P < 0.003) in p24 antigen-positive than in negative children. Thirty-nine children underwent a second evaluation 12.3 months (range 11.1-14 months) after the first. Resistance was higher (t = 3.960; P < 0.0001) at the second evaluation compared to the first. Eight of 14 children had abnormal spirometric measurements. We conclude that perinatal HIV-1 infection is associated with increased airway resistance and often abnormal spirometry. The degree of abnormalities in resistance depends on the duration of the infection rather than on HIV-1-related respiratory complications.

Local nasal immunotherapy with a powder extract for grass pollen induced rhinitis in pediatric ages: a controlled study.

Forty pediatric patients, ranging from 5-13 years of age and suffering from grass pollen rhinoconjunctivitis, were submitted to local nasal preseasonal (12 weeks) immunotherapy, either with a grass pollen extract or with placebo. After 1 year, 15 of these patients (5 previously treated with active product and 10 with placebo) were treated with the grass pollen extract preseasonally for 2 consecutive years. Before and after treatment, serum total IgA and IgE, and specific IgG and IgE were assayed as well as carrying out nasal provocation tests (NPT) with extracts at different concentrations, endpoint evaluations by rhinomanometry and prick tests with different concentrations of extract. After only 1 year, the actively treated patients showed a significant decrease of daily nasal and conjunctival signs and symptoms-as judged by a 1 to 3 score-in comparison with the control group. The placebo group showed the same results after the 3rd year. The improvement was confirmed by a significant increase of the dose threshold in NPT. No immunological alterations were evident.

Evaluation of the efficacy of oral cromolyn sodium or an oligoantigenic diet in children with atopic dermatitis: a multicenter study of 1085 patients.

One thousand eighty-five children with atopic dermatitis were enrolled in a multicenter study to evaluate the efficacy of 4 weeks of oral sodium cromoglycate or 4 weeks of a restricted diet. One thousand-eleven children (93%) concluded the study. At the end of the trial there was a significant improvement in skin lesions in the two groups: 61% of the patients in the sodium cromoglycate group and 69% in the restricted diet showed a significant improvement in atopic dermatitis. We concluded that, at least in our experimental design, both sodium cromoglycate and a restricted diet are equally effective in atopic dermatitis.

Retrospective survey on the epidemiology of H. influenzae type B meningitis in Italy (1987-91).

A retrospective survey on the epidemiology of H. Influenzae type b (Hib) meningitis was carried out in seven Italian hospitals. During the period 1987-1991, 95 (16.3%) Hib meningitis cases out of 581 bacterial meningitis cases were observed. The proportion of Hib meningitis was lowest in 1987 (11.3%); elevated in 1988 (17.9%); thereafter it did not change. A male preponderance was observed (Sex ratio 1.6). The age distribution showed that 93.7% of cases occurred in subjects < 5 years, 53.7% of cases in those < 1 year. Although Hib meningitis accounts for a small proportion of all bacterial meningitis, it is also a major problem in Italy in early childhood, because nearly all cases occur in children < 5 years.

T lymphocytes in children with recurrent respiratory infections: effect of the use of thymostimulin on the alterations of T-cell subsets.

OKT3-, OKT4- and OKT8-positive cells were estimated in 303 children with recurrent respiratory infections. The patients (selected by a score method) had experienced 13 or more infections a year. Modifications in T-cell subsets were observed in 154 patients (50.8%). Decreased OKT3- and OKT4-positive cells were present in 80 children (26.4%), while 74 patients (24.4%) showed normal values of OKT3-positive cells but decreased OKT4- and increased OKT8-positive cells. An attempt at treatment with thymostimulin was undertaken in a group of randomly chosen children with modifications in T-cell subsets. The use of thymostimulin induced the treated children more readily than the untreated ones to show improvement in both the score for respiratory infections and the distribution of T-cell subsets.

Assessment of residual immunoreactivity in red or white wines clarified with pea or lupin extracts.

Vegetable proteins could be a suitable alternative to animal proteins in the clarification of wine, but their residues could represent a risk for subjects with food allergy or intolerance. The aim of this study was to investigate the presence of specific immunoreactivity in red and white wines treated, as must or wine, with vegetable proteins in the clarification process. The proteins considered were prepared from lupins and peas, which are not included among the allergens listed in annex Illbis of Directive 2003/89/EC. The presence of residual immunoreactivity to specific rabbit anti-lupin and anti-pea polyclonal antibodies in treated wines was assessed by electrophoresis (SDS-PAGE) and immunoblotting. Residual protein was not detectable in red wines clarified with lupin, pea or a mixture of pea and lupin proteins or in white wines clarified with pea proteins. A small number of musts treated with lupin or pea proteins and white wines treated with lupin proteins yielded equivocal results, probably because of the presence of interfering material (e.g., sugar-rich proteins from grape and yeast). The use of bentonite as a secondary clarifying agent is therefore recommended since its combination with vegetable proteins is particularly effective in removing overall protein immunoreactivity.

Human immunodeficiency virus type 1 infection, clinical trials and ethics in paediatrics.

Children are not little adults and questions regarding their treatment must be directly addressed to children. Phase I and II trials should closely follow those in adults, integrated by separate studies in infants. Phase III trials should be carried out in a parallel fashion, flexible enough to be modifiable according to results from larger studies in adults. On condition that study designs are ethically impeccable and are respectful of the intrinsic social weakness of children, as many children as possible should enter clinical trials to offer wide access to drugs and ensure that questions are addressed as rapidly and efficiently as possible.