Heterogeneity of sensitization profiles and clinical phenotypes among patients with seasonal allergic rhinitis in Southern European countries-The @IT.2020 multicenter study

BACKGROUND

Pollen allergy poses a significant health and economic burden in Europe. Disease patterns are relatively homogeneous within Central and Northern European countries. However, no study broadly assessed the features of seasonal allergic rhinitis (SAR) across different Southern European countries with a standardized approach.

OBJECTIVE

To describe sensitization profiles and clinical phenotypes of pollen allergic patients in nine Southern European cities with a uniform methodological approach.

METHODS

Within the @IT.2020 multicenter observational study, pediatric and adult patients suffering from SAR were recruited in nine urban study centers located in seven countries. Clinical questionnaires, skin prick tests (SPT) and specific IgE (sIgE) tests with a customized multiplex assay (Euroimmun Labordiagnostika, Lübeck, Germany) were performed.

RESULTS

Three hundred forty-eight children (mean age 13.1 years, SD: 2.4 years) and 467 adults (mean age 35.7 years SD: 10.0 years) with a predominantly moderate to severe, persistent phenotype of SAR were recruited. Grass pollen major allergenic molecules (Phl p 1 and/or Phl p 5) ranged among the top three sensitizers in all study centers. Sensitization profiles were very heterogeneous, considering that patients in Rome were highly poly-sensitized (sIgE to 3.8 major allergenic molecules per patient), while mono-sensitization was prominent and heterogeneous in other cities, such as Marseille (sIgE to Cup a 1: n = 55/80, 68.8%) and Messina (sIgE to Par j 2: n = 47/82, 57.3%). Co-sensitization to perennial allergens, as well as allergic comorbidities also broadly varied between study centers.

CONCLUSIONS

In Southern European countries, pollen allergy is heterogeneous in terms of sensitization profiles and clinical manifestations. Despite the complexity, a unique molecular, multiplex, and customized in-vitro IgE test detected relevant sensitization in all study centers. Nevertheless, this geographical diversity in pollen allergic patients imposes localized clinical guidelines and study protocols for clinical trials of SAR in this climatically complex region.

European Position Paper on Rhinosinusitis and Nasal Polyps 2020

The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise . The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included. The full document can be downloaded for free on the website of this journal: http://www.rhinologyjournal.com.

Next-generation ARIA care pathways for rhinitis and asthma: a model for multimorbid chronic diseases

BACKGROUND

In all societies, the burden and cost of allergic and chronic respiratory diseases are increasing rapidly. Most economies are struggling to deliver modern health care effectively. There is a need to support the transformation of the health care system into integrated care with organizational health literacy.

MAIN BODY

As an example for chronic disease care, MASK (Mobile Airways Sentinel NetworK), a new project of the ARIA (Allergic Rhinitis and its Impact on Asthma) initiative, and POLLAR (Impact of Air POLLution on Asthma and Rhinitis, EIT Health), in collaboration with professional and patient organizations in the field of allergy and airway diseases, are proposing real-life ICPs centred around the patient with rhinitis, and using mHealth to monitor environmental exposure. Three aspects of care pathways are being developed: (i) Patient participation, health literacy and self-care through technology-assisted "patient activation", (ii) Implementation of care pathways by pharmacists and (iii) Next-generation guidelines assessing the recommendations of GRADE guidelines in rhinitis and asthma using real-world evidence (RWE) obtained through mobile technology. The EU and global political agendas are of great importance in supporting the digital transformation of health and care, and MASK has been recognized by DG Santé as a Good Practice in the field of digitally-enabled, integrated, person-centred care.

CONCLUSION

In 20 years, ARIA has considerably evolved from the first multimorbidity guideline in respiratory diseases to the digital transformation of health and care with a strong political involvement.

EAACI Molecular Allergology User's Guide

The availability of allergen molecules ('components') from several protein families has advanced our understanding of immunoglobulin E (IgE)-mediated responses and enabled 'component-resolved diagnosis' (CRD). The European Academy of Allergy and Clinical Immunology (EAACI) Molecular Allergology User's Guide (MAUG) provides comprehensive information on important allergens and describes the diagnostic options using CRD. Part A of the EAACI MAUG introduces allergen molecules, families, composition of extracts, databases, and diagnostic IgE, skin, and basophil tests. Singleplex and multiplex IgE assays with components improve both sensitivity for low-abundance allergens and analytical specificity; IgE to individual allergens can yield information on clinical risks and distinguish cross-reactivity from true primary sensitization. Part B discusses the clinical and molecular aspects of IgE-mediated allergies to foods (including nuts, seeds, legumes, fruits, vegetables, cereal grains, milk, egg, meat, fish, and shellfish), inhalants (pollen, mold spores, mites, and animal dander), and Hymenoptera venom. Diagnostic algorithms and short case histories provide useful information for the clinical workup of allergic individuals targeted for CRD. Part C covers protein families containing ubiquitous, highly cross-reactive panallergens from plant (lipid transfer proteins, polcalcins, PR-10, profilins) and animal sources (lipocalins, parvalbumins, serum albumins, tropomyosins) and explains their diagnostic and clinical utility. Part D lists 100 important allergen molecules. In conclusion, IgE-mediated reactions and allergic diseases, including allergic rhinoconjunctivitis, asthma, food reactions, and insect sting reactions, are discussed from a novel molecular perspective. The EAACI MAUG documents the rapid progression of molecular allergology from basic research to its integration into clinical practice, a quantum leap in the management of allergic patients.

The impact of telemonitoring on adherence to nasal corticosteroid treatment in children with seasonal allergic rhinoconjunctivitis

BACKGROUND

Adherence to controller therapy in allergic diseases is low. Telemonitoring has been proposed to improve adherence to treatment in chronic diseases. However, this strategy has never been tested in allergic rhinoconjunctivitis.

OBJECTIVE

To test whether Internet-based telemonitoring during the grass-pollen season of children with allergic rhinoconjunctivitis may enhance adherence to treatment.

METHODS

Children and adolescents, 5-18 years old, with moderate-to-severe seasonal allergic rhinoconjunctivitis to grass pollen requiring daily administration of nasal corticosteroid (NCS) (mometasone) were recruited (April 2013) in a paediatric allergy practice. Participants were randomized to Internet-based monitoring (AllergyMonitor(™) , AM) or to usual care (no diary at all, controls) and followed from 13 May (T0) to 15 June 2013 (T2). An intermediate visit (T1) was performed between 31 May and 2 June. Optimal adherence to therapy was expressed as the use of at least 0.190 g/day of mometasone, corresponding to 1 puff/nostril/day, and it was measured by canister weights during (T1) and at the end (T2) of the study period. Main secondary outcomes included the reported disease severity (validated self-questionnaire) and quality of life (AdoIRQLQ questionnaire), disease knowledge (multiple-choice questionnaire), nasal flow and resistance at baseline and at T2.

RESULTS

The use of mometasone, expressed as both optimal adherence rate (48.4% vs. 12.5%; P = 0.002) and average daily use (0.20 ± 0.12 g/day vs. 0.15 ± 0.07 g/day; P = 0.037), was higher in the AM group (n = 31) than among controls (n = 32). Disease knowledge improved among the patients using AM (83.3% vs. 68.3%; P < 0.001) but not among controls (68.2% vs. 67.7% right answers; P > 0.05). No differences were observed in the reported severity of disease, nasal flow and resistance and quality of life both at baseline and at follow-up visits.

CONCLUSIONS

Internet-based telemonitoring improves adherence to NCS treatment and disease knowledge among children and adolescents with seasonal allergic rhinoconjunctivitis.

Pilot study on the short-term prediction of symptoms in children with hay fever monitored with e-Health technology

Forecasting symptoms of pollen-related allergic rhinoconjunctivitis at the level of individual patients would be useful to improve disease control and plan pharmacological intervention. Information Technology nowadays facilitates a more efficient and easier monitoring of patients with chronic diseases. We aimed this study at testing the efficiency of a model to short-term forecast symptoms of pollen-AR at the "individual" patient level. We analysed the data prospectively acquired from a group of 21 Italian children affected by pollen-related allergic rhinoconjunctivitis and recorded their symptoms and medication "Average Combined Score" (ACS) on a daily basis during April-June 2010-2011 through an informatics platform (Allergymonitor™). The dataset used for prediction included 15 variables in four categories: (A) date, (B) meteo-climatic, (C) atmospheric concentration of 5 pollen taxa, and (D) intensity of the patient's IgE sensitization. A Partial Least Squares Discriminant Analysis approach was used in order to predict ACS values above a fixed threshold value (0.5). The best performing predicting model correctly classified 77.8% ± 10.3% and 75.5% ± 13.2% of the recorded days in the model and test years, respectively. In this model, 9/21 patients showed ≥ 80% correct classification of the recorded days in both years. A better performance was associated with a higher degree of patient's atopic sensitization and a time lag > 1. Symptom forecasts of seasonal allergic rhinitis are possible in highly polysensitised patients in areas with complex pollen exposure. However, only predictive models tailored to the individual patient's allergic susceptibility are accurate enough. Multicenter studies in large population samples adopting the same acquisition data system on smart phones are now needed to confirm this encouraging outcome.

Immunoglobulin G in IgE-mediated allergy and allergen-specific immunotherapy

Allergen-specific IgG antibodies play a significant role in allergen-specific tolerance, either naturally induced or generated by specific immunotherapy. Nevertheless, the underlying mechanisms are still debated, and allergen-specific IgG determinations are not recommended as a diagnostic tool in IgE-mediated allergy. This review summarizes the latest findings on the immunological and diagnostic role of IgG antibodies in respiratory and food allergies, and during allergen-specific immunotherapy.

Testing children for allergies: why, how, who and when: an updated statement of the European Academy of Allergy and Clinical Immunology (EAACI) Section on Pediatrics and the EAACI-Clemens von Pirquet Foundation

Allergic diseases are common in childhood and can cause a significant morbidity and impaired quality-of-life of the children and their families. Adequate allergy testing is the prerequisite for optimal care, including allergen avoidance, pharmacotherapy and immunotherapy. Children with persisting or recurrent or severe symptoms suggestive for allergy should undergo an appropriate diagnostic work-up, irrespective of their age. Adequate allergy testing may also allow defining allergic trigger in common symptoms. We provide here evidence-based guidance on when and how to test for allergy in children based on common presenting symptoms suggestive of allergic diseases.

Perspectives on allergen-specific immunotherapy in childhood: an EAACI position statement

This article is the result of consensus reached by a working group of clinical experts in paediatric allergology as well as representatives from an ethical committee and the European Medicine Agency (EMA). The manuscript covers clinical, scientific, regulatory and ethical perspectives on allergen-specific immunotherapy in childhood. Unmet needs are identified. To fill the gaps and to bridge the different points of view, recommendations are made to researchers, to scientific and patient organizations and to regulators and ethical committees. Working together for the benefit of the community is essential. The European Academy of Allergy and Clinical Immunology (EAACI) serves as the platform of such cooperation.

Prospective validation of 'Allergy-Control-SCORE(TM)': a novel symptom-medication score for clinical trials

BACKGROUND

Combined symptom and medication scores (SMS) are recommended as primary endpoints in clinical trials. Several SMS have been created, but none has been formally validated.

OBJECTIVE

To evaluate the validity of the 'Allergy-Control-SCORE© (ACS)', a novel instrument to assess patient's allergy severity by recording symptoms and rescue medication.

METHODS

One hundred and twenty-one consenting subjects (age 18-65 year), including 81 patients with allergic rhino-conjunctivitis and/or asthma and 40 healthy controls, participated in the study. They recorded daily nasal, eye, and lung symptoms using a 4-point scale (none, mild, moderate, and severe) and use of anti-symptomatic medication. Pollen counts were monitored during the study period. Symptom and medication scores values were compared to global allergy severity, quality of life, and allergy-related medical consultations. Feasibility was tested through a questionnaire on comprehensibility, easiness of use, and completeness. Retest reliability was assessed by testing consistency, in relation to pollen exposure, and for values recorded during each of 2 consecutive weeks.

RESULTS

Convergent reliability analysis indicated a highly significant correlation between ACS© and global allergy severity (P < 0.0001), quality of life (P < 0.0001), and allergy-related medical consultations (P < 0.0001). Scores were highly related to pollen counts. Allergy-Control-SCORE© showed a good retest reliability (r = 0.81; P < 0.0001) and discriminated extremely well between patients with allergy and healthy controls (6.1 ± 4.8 vs 0.2 ± 0.5; t = 10.82; P < 0.0001) with a sensitivity of 97% and a specificity of 87%. Study participants evaluated the feasibility of the SMS as excellent.

CONCLUSIONS

Allergy-Control-SCORE© is a valid and reliable instrument to assess allergy severity in clinical trials and observational studies of respiratory allergic diseases.

99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: controversial aspects of the 'hygiene hypothesis'

The 'hygiene hypothesis' proposes that the epidemic of allergic and autoimmune diseases is due to changes in the interactions between humans and the microbes of their ecosystem. This theory apparently does not explain (i) why allergic asthma is rising in 'unhygienic' American inner cities; (ii) why allergic diseases are less prevalent among migrants' children living in European big cities; (iii) why infections with airborne viruses do not 'protect' from allergic sensitization; (iv) why the inverse association between some infections (e.g. hepatitis A virus) and allergic diseases has been reproduced in some populations, but not in others; and (v) why probiotics are not effective in the prevention and therapy of allergic diseases. These challenging questions are useful starting points to improve our understanding of the hypothesis, and to identify among the infectious agents those really responsible for a protective influence against atopic and autoimmune diseases.

Dynamic evolution of serum immunoglobulin E to airborne allergens throughout childhood: results from the Multi-Centre Allergy Study birth cohort

BACKGROUND

Allergic rhinoconjunctivitis and asthma evolve dynamically throughout childhood. Yet, data on the evolution of serum levels of IgE antibodies against airborne allergens throughout the first decade of life are scarce.

OBJECTIVE

To describe the patterns of new and persistent sensitization against airborne allergens including remission from birth to 10 years of age and the long-term clinical outcomes up to the age of 13 years.

METHODS

In 273 children from the Multi-Centre Allergy Study, a German birth cohort, IgE levels were determined against airborne allergens (Dermatophagoides pteronyssinus, cat and dog dander, birch and grass species pollens) at 2, 5, 7, and 10 years of age (ImmunoCAP, Phadia); allergic rhino-conjunctivitis and asthma were ascertained at the 13 years of age through a standardized questionnaire (International Study of Asthma and Allergies in Childhood).

RESULTS

The prevalence of sensitization to each allergen increased steadily throughout childhood, and a hierarchy of sensitization prevalence (grass>birch>mites>cat>dog) was maintained from 5 years of age onwards. A mono-sensitization state was relatively short (measurable half-life=3 years) as additional sensitizations were acquired frequently, and relatively soon after the first one. Remission of weak sensitization (UNICAP classes 1-2) was also quite frequent, especially before 5 years of age. By contrast, stronger IgE responses (>3.5 kU/L) were invariably persistent. Early sensitization was associated with a higher tendency for poly-sensitization at 10 years of age and allergic rhino-conjunctivitis and/or asthma at 13 years of age.

CONCLUSIONS

IgE responses against airborne allergens undergo dynamic changes throughout childhood, with a high frequency of new sensitization or remission. The long-term persistence and the clinical impact of IgE responses are affected by the intensity of IgE sensitization and the age of its onset.

Longitudinal trends of total and allergen-specific IgE throughout childhood

BACKGROUND

The development and the quantitative relationship between allergen-specific IgE (S-IgE) responses and total IgE (T-IgE), during childhood and adolescence have not been described and understood in detail. The objective of this study was to describe and compare the longitudinal trends of serum levels of S-IgE and T-IgE during childhood.

METHODS

We analysed data from participants in the MAS birth cohort study at 2, 5, 7 and 10 years of age (n = 273) and at 1, 3, 5, 6, 7, 10 and 13 years (n = 84). Total-IgE and the overall level of specific-IgE against nine locally relevant airborne and food allergens were determined by FEIA (ImmunoCAP). Allergic rhino-conjunctivitis and asthma were ascertained by questionnaires.

RESULTS

Longitudinal patterns of T-IgE levels from age 1 to 13 years were highly heterogeneous (declining, flat or increasing with different profiles). From 5 years of age, logarithmic (log(10)) transformed values of T-IgE and of S-IgE levels tend to follow a parallel trend, so that their relation remained constant throughout school age. A flat trend of T-IgE vs a constantly increasing trend of T-IgE was associated with a low or, respectively, high rate of wheezing at 13 years of age.

CONCLUSIONS

Beginning at the age of 5 years, total serum IgE levels in children from an industrialized country evolved in parallel with overall S-IgE levels. Therefore, variations in T-IgE levels at school age closely reflect variations in overall S-IgE levels. Further studies are required to strengthen the biological and clinical implication of this novel finding.

Wheezing in childhood: incidence, longitudinal patterns and factors predicting persistence

Childhood asthma is frequently perceived as a disease with uniform clinical pathways. This perception might be an oversimplification. The aim of the present study was to investigate the incidence and natural course of wheeze over the first 13 yrs of life and analyse the risk factors predicting wheeze at 11-13 yrs of age. The Multicentre Allergy Study, a German birth cohort, recruited 1,314 children in 1990. Physical examinations, interviews on atopic diseases, immunoglobulin (Ig)E and lung function tests were performed up to 13 yrs of age. Complete data on the course of wheeze were available for 441 children. It was found that incidence of wheezing declined with age. The first wheezing episode was reported by 29, 9 and 9% of participants at < or = 3 (early wheezers), 3-6 (late wheezers), and > 6 yrs (very late wheezers) of age, respectively. Wheezing at the age of 13 yrs was associated with parental atopy, and with IgE sensitisation to common allergens, elevated total IgE and exposure to high levels of indoor allergens in early life. All these associations were remarkably stronger among early wheezers than among early nonwheezers. In conclusion, the relevance of an early expression of atopy as a predictor of wheezing at age 13 yrs declines with increasing age of wheezing onset.

Primary versus secondary immunoglobulin E sensitization to soy and wheat in the Multi-Centre Allergy Study cohort

BACKGROUND

IgE sensitization to soy and wheat is classified as 'primary' when generated by food ingestion and 'secondary' when it as a consequence of primary sensitization to cross-reacting pollen antigens via inhalation. The age-specific relevance of these categories of sensitization throughout childhood is unknown.

OBJECTIVE

To monitor the natural course of IgE sensitization against common food allergens in childhood in relation to sensitization against cross-reactive airborne allergens.

METHODS

The German Multi-Centre Allergy Study with follow-up from birth to age 13 recruited initially 1314 children. IgE antibody levels against cow's milk, hen's egg, soy, wheat, mites, cat and dog dander, birch and grass pollens were tested. Longitudinal data were analysed from the 273 children with sera obtained at age 2, 5, 7 and 10 years of age.

RESULTS

The point prevalence of sensitization (>1.0 kU/L) to milk and egg allergens progressively decreased from about 4% at 2 years to <1% at 10 years. By contrast, the prevalence of IgE to wheat and soy progressively increased with age, from 2% to 7% (soy) and from 2% to 9% (wheat). At 10 years of age, IgE to grass pollen was detected in 97% and 98% of the children reacting against soy and wheat, respectively; IgE to birch pollen was observed in 86% and 82% of the children reacting against soy and wheat, respectively. Early IgE sensitization to soy or wheat preceded that to grass or birch pollen in only 4% and 8% of participants sensitized to soy and wheat, respectively.

CONCLUSION

IgE sensitization to soy and wheat is relatively uncommon and mostly primary in early infancy, more frequent and mostly secondary to pollen sensitization at school age. Clinical Implications Awareness should be raised to avoid unnecessary diet restrictions due to the high frequency of clinically irrelevant, secondary sensitization to soy and wheat in schoolchildren with pollinosis.

Primary prevention of allergy: avoiding risk or providing protection?

Primary prevention strategies of allergy so far have been aimed to fight allergy causes, by avoiding risk factors and inhibiting their mechanisms of action. The results of trials testing food or airborne allergen avoidance as a prevention strategy were, however, rather disappointing. A reverse approach for primary prevention of allergies aims to facilitate exposure to protecting factors which promote the induction of immunologic tolerance against innocuous antigens. These factors are associated with farming environment and a 'traditional lifestyle', but identification of these factors is quite difficult. Major candidates include food-borne microbes, helminths or their components, which are able to stimulate mucosal immunity, particularly in the gut. Similarly, new preventive and therapeutic strategies are being tested to induce specific food-allergen oral tolerance through the ingestion of progressively increasing doses of the offending food. This shifting of allergy prevention research from avoidance to tolerance induction will hopefully allow us to reverse the epidemic trend of allergy diseases.

Intranasal delivery of whole influenza vaccine prevents subsequent allergen-induced sensitization and airway hyper-reactivity in mice

BACKGROUND

Infection with influenza virus has been associated with seemingly opposing effects on the development of asthma. However, there are no data about the effects of mucosal vaccination with inactivated influenza on the inception of allergic asthma.

OBJECTIVE

To assess the immunological effects of inhaled inactivated influenza vaccine, using two different types of flu vaccines, on the inception of allergic sensitization and allergen-mediated airway disease in a mouse model.

METHODS

BALB/c mice were intranasally or intratracheally vaccinated with whole or split influenza virus vaccine (days -1 or -1, 27) before systemic sensitization with ovalbumin (OVA) (days 1, 14) and repeated airway allergen challenges (days 28-30). Allergen sensitization (IgE serum levels), airway inflammation (differential cells in bronchoalveolar lavage fluid) and airway hyper-reactivity (AHR) (in vivo lung function) were analysed.

RESULTS

The intranasal instillation of whole influenza vaccine before allergen sensitization significantly reduced the serum levels of total and OVA-specific IgE as well as allergen-induced AHR. Prevention was due to an allergen-specific shift from a predominant T helper (Th)2- towards a Th1-immune response. Application of split influenza vaccine did not show the same preventive effect.

CONCLUSION

Intranasal administration of inactivated whole influenza vaccine reduced subsequent allergen sensitization and prevented allergen-induced AHR. Our results show that the composition of the influenza vaccine has a major influence on subsequent development of allergen-induced sensitization and AHR, and suggest that mucosal inactivated whole influenza vaccination may represent a step towards the development of a preventive strategy for atopic asthma.

The asthma-obesity link in childhood: open questions, complex evidence, a few answers only

Obesity and asthma are public health priorities in developed countries. Genes which may contribute to the control of both conditions include those encoding for the beta2-adrenergic receptor, tumour necrosis factor-alpha (TNF-alpha) and the insulin-like growth factor 1 (IGF-1). Prospective studies consistently supported a link between obesity and reported wheezing or asthma diagnosis in children. However, there are still no clear explanations for such a link. On one hand, overweight asthmatic children may perceive their asthma as worse. On the other hand, atopic sensitization and bronchial hyper-reactivity do not explain the observed associations. After puberty, the association between asthma and obesity tends to be stronger in girls than in boys. It is conceivable that severe obesity in adolescent females may aggravate asthma through mechanisms different from those linking prepubertal obesity to unremitting asthma in males. Future studies should therefore address multiple age- and gender-specific hypotheses about the mechanisms that link obesity to asthma throughout childhood.

The inverse association of salmonellosis in infancy with allergic rhinoconjunctivitis and asthma at school-age: a longitudinal study

BACKGROUND

Respiratory allergies are inversely related to early acquisition of food-borne and fecal-oral infections, consumption of unpasteurized milk, early exposure to stables and high endotoxin concentrations in a farming environment. We tested therefore if infection by Salmonella in early life can protect from development of respiratory allergies later in life.

METHODS

During 2003, we studied two groups of Sardinian children (age 6-18 years) who had been hospitalized before 4 years of age (during 1989-2001) with non-typhoid salmonellosis (n = 148) or acute enteritis of nonbacterial etiology (NB-enteritis) (n = 167). Allergic rhinoconjunctivitis (AR) and asthma were evaluated by telephonic interview with a ISAAC questionnaire; participants reporting AR and/or asthma were further examined through a complete diagnostic work-up to objectively confirm or exclude current disease. Kaplan-Meier curves and Cox proportional hazard models were used to analyze the role of different types of enteritis on the risk of developing allergic rhinoconjunctivitis or asthma over time.

RESULTS

Children who had been hospitalized with salmonellosis had a lower prevalence of allergic rhinoconjunctivitis (eight of 148, 5.4%vs 23 of 167, 13.8%; P = 0.019) or asthma (five of 148, 3.4% vs 21 of 167, 12.6%; P = 0.006) than those who had been hospitalized with NB-enteritis. The proportional hazard of salmonellosis for asthma was 0.23 (95% CI: 0.08-0.67; P < 0.01) and for allergic rhinoconjunctivitis was 0.40 (95% CI: 0.17-0.95; P = 0.04), after adjusting for confounders.

DISCUSSION

The strength of the observed associations suggests that Salmonella may contribute to shape the natural history of respiratory allergies. However, further studies are needed to test in other settings the association observed in Sardinian children. We speculate that clinical or subclinical infection by Salmonella may contribute to the atopy protective influence of a traditional farming environment or of areas endemic for food-borne and fecal-oral infections. Food hygiene and prevention of salmonellosis must remain however a public health priority.

Allergy, asthma and markers of infections among Albanian migrants to Southern Italy

BACKGROUND

Studies of immigrants represent an useful tool to determine the relative relevance of environmental vs genetic factors in causing the reported rapid increase of the prevalence of sensitization and allergic diseases.

METHODS

A total of 152 Albanian migrants to Southern Italy responded to a questionnaire based on the European Community Respiratory Health Survey (ECRHS) and 139 of them underwent skin prick test, and 61 serological assays for total IgE and IgG antibodies against Toxoplasma gondii (TG), herpes simplex virus 1 (HSV-1), hepatitis A virus (HAV) and Helicobacter pylori (HP).

RESULTS

Reported asthma was rare (2/152; 1.3%) and reported nasal allergies rather frequent (24/152; 15.8%). Sensitization to common inhalant allergens occurred in 27/139 (19.4%) subjects. The frequency of skin sensitization to pollen (P = 0.003) and that of hay fever (P = 0.004) increased with the time spent in Apulia. All the 61 sera had antibodies against HAV, 59/61 (96.7%) against HSV-1, 48/61 (78.7%) against HP and 34/61 (55.7%) against TG. The prevalence of skin sensitization and hay fever symptoms were correlated to the duration of residence in Southern Italy.

CONCLUSIONS

Data presented indicate that Albanian migrants to Italy, in spite of the low prevalence of allergic diseases and sensitization in their country of origin, manifest with time an increasing prevalence of sensitization to local allergens and nasal symptoms after immigration to Italy. This would suggest a permanent role of allergen exposure and lifestyle factors in influencing the appearance of sensitization and symptoms of allergic diseases.

The heterogeneity of allergic phenotypes: genetic and environmental interactions

OBJECTIVE

This article reinforces the reader's knowledge of the multifactorial nature of allergic diseases and of the heterogeneity of allergic phenotypes.

DATA SOURCES

Personal studies and an evidence-based approach is used to support the assumption that three major abnormalities concur in the pathophysiology of allergic diseases: 1) enhanced allergen recognition and specific immune response; 2) a T helper 2 cytokine profile that results in polyclonal immunoglobulin E activation and mast cell-eosinophilic inflammation; and 3) organ hyperreactivity.

STUDY SELECTION

Examples of genetic and environmental factors that preferentially influence each of these distinct pathophysiologic abnormalities are provided.

RESULTS

Data presented indicate that allergic diseases distribute along a wide spectrum depending on the preferential pathophysiologic abnormalities operating in the individual patient.

CONCLUSIONS

Categorization of allergic patients into distinct clinical phenotypes might result in a more patient-oriented (rather than disease-oriented) approach, and hence, better management.

Prevalence of atopy and asthma in eastern versus western Europe: why the difference?

LEARNING OBJECTIVES

This article reinforces the reader's knowledge of the epidemiology of allergy and asthma in eastern versus western European countries and the ability to recognize the different hypotheses formulated to explain the rising trend of allergic asthma in Europe.

DATA SOURCES

Articles in English comparing the epidemiology of allergy in eastern versus western Europe published before December 31, 2000.

RESULTS

Significant higher prevalences of atopy and allergic asthma were observed in the early 1990s among populations living in western compared with eastern European countries. Changes in lifestyle after the fall of the communist system were associated with an increasing trend of atopic sensitization and hay fever in former East Germany after only 6 to 8 years after the Germany reunification. It has been hypothesized that a similar "converging" trend in the prevalence of allergic asthma and of bronchial hyperresponsiveness may take longer periods.

CONCLUSIONS

The prevalence of allergic asthma has increased decades earlier in western Europe with respect to eastern Europe. This is probably attributable to changes in lifestyle that had already occurred rather than to air pollution. The factors of a western lifestyle (diet, hygiene, varied allergen exposure) that have determined the difference in allergic asthma prevalence across Europe have yet to be identified.

Are infections protecting from atopy?

The 'Hygiene Hypothesis' proposes that overcrowding and unhygienic contacts early in life may protect from atopic diseases by facilitating exposure to microbes. Longitudinal studies have recently shown that among subjects exposed early in life to other children at home, or at day care, the risk of wheezing steadily declined with age to levels significantly lower than controls. Evidences supporting a protective role of respiratory infections or BCG immunization on the development of allergic asthma are still insufficient. By contrast, the observation of a lower prevalence of atopic sensitization among children raised on a farm has been consistently reproduced. Several new studies have recently investigated the role of changes of human microbial flora, declining exposure to foodborne and orofecal infections, to helminths and to environmental sources of endotoxin as putative contributors to the rise of allergy and asthma cases among populations living with a western lifestyle.

Exposure to foodborne and orofecal microbes versus airborne viruses in relation to atopy and allergic asthma: epidemiological study

OBJECTIVE

To investigate if markers of exposure to foodborne and orofecal microbes versus airborne viruses are associated with atopy and respiratory allergies.

DESIGN

Retrospective case-control study.

PARTICIPANTS

240 atopic cases and 240 non-atopic controls from a population sample of 1659 participants, all Italian male cadets aged 17-24.

SETTING

Air force school in Caserta, Italy.

MAIN OUTCOME MEASURES

Serology for Toxoplasma gondii, Helicobacter pylori, hepatitis A virus, measles, mumps, rubella, chickenpox, cytomegalovirus, and herpes simplex virus type 1; skin sensitisation and IgE antibodies to relevant airborne allergens; total IgE concentration; and diagnosis of allergic asthma or rhinitis.

RESULTS

Compared with controls there was a lower prevalence of T gondii (26% v 18%, P=0.027), hepatitis A virus (30% v 16%, P=0.004), and H pylori (18% v 15%, P=0.325) in atopic participants. Adjusted odds ratios of atopy decreased with a gradient of exposure to H pylori, T gondii, and hepatitis A virus (none, odds ratio 1; one, 0. 70; two or three, 0.37; P for trend=0.000045) but not with cumulative exposure to the other viruses. Conversely, total IgE concentration was not independently associated with any infection. Allergic asthma was rare (1/245, 0.4%) and allergic rhinitis infrequent (16/245, 7%) among the participants (245/1659) exposed to at least two orofecal and foodborne infections (H pylori, T gondii, hepatitis A virus).

CONCLUSION

Respiratory allergy is less frequent in people heavily exposed to orofecal and foodborne microbes. Hygiene and a westernised, semisterile diet may facilitate atopy by influencing the overall pattern of commensals and pathogens that stimulate the gut associated lymphoid tissue thus contributing to the epidemic of allergic asthma and rhinitis in developed countries.

Mimicking microbial 'education' of the immune system: a strategy to revert the epidemic trend of atopy and allergic asthma?

Deficient microbial stimulation of the immune system, caused by hygiene, may underly the atopy and allergic asthma epidemic we are currently experiencing. Consistent with this 'hygiene hypothesis', research on immunotherapy of allergic diseases also centres on bacteria-derived molecules (eg DNA immunostimulatory sequences) as adjuvants for allergen-specific type 1 immune responses. If we understood how certain microbes physiologically 'educate' our immune system to interact safely with environmental nonmicrobial antigens, we might be able to learn to mimic their beneficial actions. Programmed 'immunoeducation' would consist of safe administration, by the correct route, dose and timing, of those microbial stimuli that are necessary to 'train' the developing mucosal immune system and to maintain an appropriate homeostatic equilibrium between its components. Overall, this would result in a prevention of atopy that is not limited to certain specific allergens. Although such a strategy is far beyond our present potential, it may in principle revert the epidemic trend of atopy and allergic asthma without jeopardizing the fight against infectious diseases.

Incidence of Helicobacter pylori infection in a cohort of Italian military students

Prevalence and incidence of Helicobacter pylori infection among 250 Italian military students were studied using specific IgG antibodies. Subjects susceptible at enrollment were evaluated during a 10-month follow-up period, when two serum samples were collected after 5 and 10 months, respectively. Samples were also analyzed for anti-CagA (a protein associated with virulent H. pylori strains) IgG antibodies. Finally, spectrotypic analysis by isoelectric focusing and reverse blotting (IEFRB) was performed in the majority of positive samples. Forty-three out of 250 (17.2%) were positive at the time of enrollment, a seroprevalence rate very similar to that observed in a larger Italian military population 5 years earlier. Among the 207 susceptible subjects, two seroconverted at 5 months after enrollment; they were still positive at the end of follow-up (incidence rate of 1.16 per 100 person/years of exposure). This data suggests a spread of H. pylori in the Italian military population that is not negligible. Nearly all anti-H. pylori-positive subjects were also CagA antibody positive (agreement percentage: 97.6%; K = 0.91), suggesting that the large majority of H. pylori strains were of the virulent type. Sixty-four percent of positive sera presented an oligoclonal spectrotype, which seems to be a hallmark of humoral immune response to H. pylori.

Association of persistent bronchial hyperresponsiveness with beta2-adrenoceptor (ADRB2) haplotypes. A population study

Bronchial hyperresponsiveness (BHR) is a hallmark of asthma and represents a strong risk factor for the disease. However, not all asthmatics have BHR and it can be observed in normal subjects too, probably because of genetic predisposition. Increasing attention is being focused on the beta2-adrenoceptor gene (ADRB2), whose genetic variability at amino acids 16 and 27 has been shown to correlate with some clinical features of asthma, including airways reactivity. To verify whether ADRB2 gene polymorphisms can influence BHR at a broader level, we studied a large, highly homogeneous sample of individuals sharing race, gender, age, and current living environment. BHR was strictly defined as a constant positive response to serial methacholine challenge tests and an improved definition of genetic variability at the ADRB2 locus was used, by identifying the haplotypic combinations of polymorphisms 16 and 27. We observed that the ADRB2 haplotype with a Gly at position 16 and a Gln at position 27 is associated with BHR in our sample. The association persisted also after correction for potentially confounding variables such as specific and total IgE levels. This observation suggests therefore that ADRB2 gene can confer genetic susceptibility to BHR, rather than having only a disease-modifying effect in asthma.

Sibship size, birth order, and atopy in 11,371 Italian young men

BACKGROUND

Having a low number of siblings and a low birth order has been reported to be a relevant risk factor for development of atopic diseases and skin sensitization to common inhalants. Although the inverse association of atopy with sibship size has been confirmed repeatedly, the association with birth order has provided conflicting results. This possibly is due to the relatively small size of the population sample examined.

OBJECTIVE

The objective of this study was to investigate the relation between sibship size, birth order, and atopy in a very large population sample, highly homogeneous for age and sex.

METHODS

This was a retrospective survey of 11,371 Italian young men, 18 to 24 years old, all candidates for enrollment in the Italian Air Force. Demographic data had been collected by a standard questionnaire. Specific IgE for locally relevant airborne allergens had been tested by a multi-RAST assay (CAP-Phadiatop).

RESULTS

The prevalence of atopy (defined as a high level of specific IgE against inhalants [cut-point >1.2 log RU]) was inversely related to the total number of siblings (25% in those with no siblings and 9% in those with five or more siblings), with a mean of a 3% decrease in prevalence for each added sibling. This relation persisted after adjustment for relevant variables such as father's education and rural and southern residence. An independent association between birth order and atopy was also observed because the decrease in atopy prevalence with increasing numbers of older siblings was significantly steeper than that found with the number of younger siblings (chi2 = 179, df = 1, p < 0.0001).

CONCLUSIONS

In a very large and homogeneous population sample of a Mediterranean country, not only sibship size but also birth order was significantly associated with atopy. This observation further highlights the role of family structure in the development of atopy and supports the hypothesis that cross-infections acquired early in infancy or in later childhood might prevent development of atopy later in life.

Prevalence of Helicobacter pylori infection in a cohort of Italian military students

In 1990, to study regional prevalences and risk factors of Helicobacter pylori infection in healthy young adult males, sera were collected from a nationwide sample of 1659 males (mean age 20.7 years) at introduction into the Air Force School for military students in Caserta, Italy. An enzyme-linked immunosorbent assay was used to detect H. pylori specific immunoglobulin G antibodies. The observed overall seropositivity rate was 17.5% (95% CI 15.7-19.4). Prevalence was higher in southern Italy and in the Italian islands as compared with northern Italy and central Italy (21.3% vs. 9.5%). Multiple logistic regression analysis showed that residence in southern areas and islands was the strongest predictor of the likelihood of H. pylori seropositivity; number of siblings in the household was marginally associated; years of father's schooling was not a significant predictor. H. pylori positive subjects were more likely positive for antibodies to hepatitis A virus infection (anti-HAV) than those H. pylori negative (35.4% vs. 24.9%; Odds Ratio 1.7, 95% CI 1.3-2.2). Adjustment for the confounding effect of sociodemographic variables weakened this association (OR 1.3, 95% CI 1.0-1.7). These findings suggest that differences in environmental conditions rather than in socioeconomic status may have played the major role in the different spread of H. pylori infection across the country.

Cross sectional retrospective study of prevalence of atopy among Italian military students with antibodies against hepatitis A virus

OBJECTIVE

To investigate the working hypothesis that common infections occurring early in life prevent atopy.

DESIGN

Cross sectional, retrospective study of young Italian men with results for hepatitis A serology and atopy.

SETTING

Air force school of military students in Caserta, Italy.

SUBJECTS

1659 male students aged 17-24, most of whom (90%) were from central and southern Italy.

MAIN OUTCOME MEASURES

Skin sensitisation and specific IgE antibodies to locally relevant airborne allergens; diagnosis of respiratory allergy (asthma or rhinitis, or both); hepatitis A seropositivity.

RESULTS

443 of the 1659 subjects (26.7%) were positive for hepatitis A virus antibody. Atopy was less common among seropositive than seronegative subjects according to skin sensitization (weal reaction > or = 3 mm) to one or more allergens (21.9% (97/443) v 30.2% (367/1216), P < 0.001); polysensitisation (sensitive to three or more allergens) (2.7% (12/443) v 6.4% (78/1216), P < 0.01); high specific IgF concentration (9.7% (43/443) v 18.4% (224/1216), P < 0.00005); and lifetime prevalence of allergic rhinitis or asthma, or both (8.4% (37/443) v 16.7% (203/1216), P < 0.001). Hepatitis A seropositivity remained inversely associated with atopy after adjusting for father's education, the number of older siblings, and the area of residence (based on the number of inhabitants). The prevalence of atopy was constantly low among seropositive subjects, whatever the number of older siblings; by contrast, it increased with a decreasing number of older siblings among seronegative subjects.

CONCLUSION

Indirect but important evidence is added to the working hypothesis as common infections acquired early in life because of the presence of many older siblings (among seronegative subjects) or because of unhygienic living conditions (among seropositive subjects) may have reduced the risk of developing atopy.

Lack of evidence for a superantigen in lymphocytes from HIV-discordant monozygotic twins

OBJECTIVE

An HIV-associated superantigen (SAg) has been hypothesized. Here we test whether an SAg is functionally detectable in peripheral blood mononuclear cells (PBMC) from monozygotic twins discordant for HIV infection.

DESIGN AND METHODS

The V beta selective T-cell depletion found in minor lymphocyte stimulation (Mls)-positive mice is caused by an SAg encoded by the mouse mammary tumour virus. Mls is a locus whose gene product stimulates a mixed lymphocyte reaction (MLR) in mice strains identical at the major histocompatibility complex locus. If an SAg is present in PBMC and/or sorted CD4+ cells from one HIV-infected monozygotic twin, it would stimulate PBMC from the corresponding healthy monozygotic twin in an MLR. In addition, if an SAg causes V beta-selective T-cell depletion in AIDS patients, a differential proliferation to a panel of staphylococcal enterotoxins (SE) of T lymphocytes from healthy and HIV-infected monozygotic twins should become measurable.

RESULTS

No positive MLR or significant differences in the SE-driven proliferation between the healthy and the HIV-infected twins were observed.

CONCLUSIONS

Our results suggest that PBMC from the two HIV-infected twins do not express a functionally detectable SAg.

Functional analysis of two tetanus toxin universal T cell epitopes in their interaction with DR1101 and DR1104 alleles

In this study we have investigated the interaction between two DR11 alleles (DB*1101 and DB*1104) and two previously described tetanus toxin (tt) universal T cell epitopes P2(tt830-843) and P30(tt947-967) by means of a functional cytotoxic competition assay. Both truncation analysis and single alanine substitution analysis were performed. In addition, the capacity of truncated and single alanine substituted peptides to be recognized by human T cell clones from donors bearing the DR1101 or DR1104 alleles was assessed. In the case of truncated peptides the same binding and recognition pattern was observed with both alleles. Longer peptides were better competitors and more potent stimulators, a result that should be taken into account when these peptides are used as immunogens. None of the single alanine substitutions could abrogate or strongly diminish the inhibitory capacity of the analogues tested indicating the lack of strong "anchor residues" present in P2 and P30 and implicated in DR binding. In addition, although the original peptide sequences were presented to specific T cell clones with comparable efficiency, some of the alanine single substituted peptides were better recognized in association with one of the alleles by clones derived from individuals bearing the homologous allele. The only exception was the tt951-967 analogue ttW955A, which was preferentially recognized in association with the DR1104 allele regardless of the clone tested. This suggests that, although it binds to both alleles with comparable efficiency, the MHC-peptide complex so formed is conformationally distinguishable by specific T cell clones.

Functional analysis of two tetanus toxin universal T cell epitopes in their interaction with DR1101 and DR1104 alleles

In this study we have investigated the interaction between two DR11 alleles (DB*1101 and DB*1104) and two previously described tetanus toxin (tt) universal T cell epitopes P2(tt830-843) and P30(tt947-967) by means of a functional cytotoxic competition assay. Both truncation analysis and single alanine substitution analysis were performed. In addition, the capacity of truncated and single alanine substituted peptides to be recognized by human T cell clones from donors bearing the DR1101 or DR1104 alleles was assessed. In the case of truncated peptides the same binding and recognition pattern was observed with both alleles. Longer peptides were better competitors and more potent stimulators, a result that should be taken into account when these peptides are used as immunogens. None of the single alanine substitutions could abrogate or strongly diminish the inhibitory capacity of the analogues tested indicating the lack of strong "anchor residues" present in P2 and P30 and implicated in DR binding. In addition, although the original peptide sequences were presented to specific T cell clones with comparable efficiency, some of the alanine single substituted peptides were better recognized in association with one of the alleles by clones derived from individuals bearing the homologous allele. The only exception was the tt951-967 analogue ttW955A, which was preferentially recognized in association with the DR1104 allele regardless of the clone tested. This suggests that, although it binds to both alleles with comparable efficiency, the MHC-peptide complex so formed is conformationally distinguishable by specific T cell clones.

Incidence of hepatitis B virus infection among an Italian military population: evidence of low infection spread

In 1990, a prospective serological survey to estimate the rate of clinical and inapparent infection with hepatitis B virus was performed in a cohort of 1324 soldiers, 18-24 years old, during an eight-month period in Italy. At the time of enrollment the prevalence of hepatitis B markers was 4.6% (0.7% subjects positive for hepatitis B surface antigen [HBsAg], 3.0% positive for antibody to hepatitis B surface antigen [anti-HBs], and 0.9% positive for antibody to hepatitis B core antigen [anti-HBc] alone. Among the 1263 susceptible subjects who were followed-up, only 2 (0.24/100 person-years of exposure) had seroconversion for HBV markers, none of which was associated with clinical illness. Among the 9 subjects HBsAg-positive at the time of enrollment, 1 (11.2%) had lost HBsAg at the end of follow-up. These data show a low spread of HBV infection among Italian young generations.

Incidence of hepatitis A virus infection among an Italian military population

In 1990, a prospective serological survey to estimate the rate of clinical and inapparent infection with hepatitis A virus (HAV) was performed in a cohort of 1,268 soldiers, 18-24 years old, during an 8 month period in the Campania region in Italy. At the time of enrollment 318 (25%) of the 1,268 soldiers were positive for total antibodies to HAV (anti-HAV). None of them was positive for IgM anti-HAV. Among the 950 susceptible subjects who were followed up for 8 months, eight (0.8%) later seroconverted to anti-HAV positivity. This figure corresponds to an incidence of 1.3/100 person/years (eight seroconversions during 633.3 years of observation). There were two clinical (with presence of IgM-anti-HAV) and six inapparent infections. The clinical/subclinical HAV ratio was 1:3. These findings indicate that the risk of HAV infection among soldiers residing in this area is not negligible.

Evaluation of the overall degree of sensitization to airborne allergens by a single serologic test: implications for epidemiologic studies of allergy

In most epidemiologic studies of respiratory allergy, the overall degree of sensitization is usually measured by indices based on skin prick test reactions to a panel of relevant airborne allergens. In the present study we used a single assay (CAP-Phadiatop, Pharmacia, Uppsala, Sweden), which is based on the reaction between serum-specific IgE and a mixture of locally relevant inhalant allergens to measure the degree of sensitization to inhalants in the sera of 1815 young Italian men, in whom a complete diagnostic workup for respiratory allergy was performed in parallel. The intensity of reaction in the CAP-Phadiatop assay was highly correlated with: (1) an allergy index (p < 0.005), based on skin prick test reactivity to seven relevant inhalant allergens (Dermatophagoides pteronyssinus, mixed grass pollens, cat epithelium, Parietaria judaica, Olea europaea, Artemisia vulgaris, Alternaria tenuis); (2) the concentration of specific IgE to the same allergens, measured by CAP-RAST (p < 0.001), in both monosensitized and polysensitized subjects; (3) the rate of respiratory allergic diseases (p < 0.0001). Therefore CAP-Phadiatop intensity of reaction is a reliable indicator of the overall degree of sensitization to inhalant allergens. Furthermore, as demonstrated by relative operating characteristic analysis, it has an acceptable detectability power in identifying subjects with symptomatic expression of the atopy status [P(A) = 0.948]. The evaluation of the degree of sensitization to inhalants by a single and semiautomated assay represents a step forward in the standardization of procedures for epidemiologic studies of inhalant allergic diseases and for mass screening programs, which are aimed at identifying predictive markers of disease susceptibility.

The changing epidemiology of hepatitis A in Italy

In 1990, the prevalence of antibodies to hepatitis A virus infection (anti-HAV) was assayed by the ELISA method on a national sample of 1000 recruits aged 18-24 years. The overall prevalence was 29.4% (22.4% in the northern and central regions, 32.2% in the south and islands; p < 0.01). Compared with a similar study conducted in 1981, the results show a marked reduction in anti-HAV prevalence (from 66.3% to 29.4%; p < 0.01). These findings reflect the improved sanitation standards in Italy and indicate that the proportion of non-immune adults is increasing, with a higher risk of symptomatic infection in the near future.

Antibody response to meningococcal polysaccharides A and C in patients with complement defects

Patients with defects of terminal complement components are particularly exposed to the risk of developing neisserial infections and seem to respond poorly to meningococcal capsular polysaccharide (PS) C via natural immunization. The sole meningococcal PSC is, on the other hand, an excellent immunogen in normal people. Considering the great importance of vaccine prophylaxis for the prevention of meningococcal infections in patients with complement defects, it is crucial to study the antibody response to the sole meningococcal PS in these patients. We therefore analysed the levels of anti-PSA and PSC antibodies in the members of four families including patients with homozygous and heterozygous defects of C7, C8 or factor H, before and after vaccination with the sole PSA + C. Surprisingly, we found the highest levels of antibodies before vaccination in homozygous subjects, followed by heterozygous and normal controls, whereas, after vaccination, homozygous subjects showed the lowest increase of specific antibodies, indicating their relative incapability to respond to sole meningococcal PS. In conclusion, this study demonstrates (1) the capacity to respond to meningococcal PS via natural immunization by patients with total complement defects, and (2) the low responsiveness to meningococcal PS via vaccine immunization by the same patients. We propose that vaccination should be given to patients lacking specific antibodies and their serological response should be assessed. In addition this study confirms previous observations on a likely lower immunogenic power of meningococcal serogroup C via natural immunization compared with the better immunogenicity of the sole PSC.

Clinical and immunological response to typhoid vaccination with parenteral or oral vaccines in two groups of 30 recruits

The clinical and immunological responses to typhoid vaccination with parenteral and oral vaccines in two groups of 30 adult male subjects were studied. Specific anti-Salmonella typhi cell-mediated immunity and total or specific anti-lipopolysaccharide faecal immunoglobulin (Ig) A titres in vaccinated subjects were monitored. Cellular antibacterial activity was significantly increased only in orally vaccinated subjects. Serum arming activity and inhibition experiments suggested an IgA-dependent cellular cytotoxicity in those orally vaccinated. In these subjects, a total and anti-lipopolysaccharide faecal IgA increase was observed lasting up to 8 months after completion of the vaccination schedule. In parenteral vaccinated subjects, an early onset transitory increase of IgM rheumatoid factor was observed. Oral vaccine was well tolerated and free of side effects, whereas 65% of parenterally vaccinated subjects reported side effects such as fever, headache, malaise and local tenderness in the injection site.