[Allergy and the environment]

The prevalence of allergic diseases has increased in modern Western countries during the last decades. Among the hypotheses for the reasons the idea that environmental pollutants may play a role is intensively discussed. In order to characterise the influence of these pollutants on the development, elicitation and chronification of allergic reactions (allergotoxicology) epidemiological, clinical and experimental data have to be considered. These investigations showed that among the pollutants with an enhancing effect on allergic diseases pollution types with nitrogen oxides (NOx), ozone (O3), tobacco smoke, particulate matter and diesel exhaust particles are of special interest.

The development of a new information model for a pediatric cancer registry on late treatment sequelae in The Netherlands

Worldwide, the need is felt for life time follow up of survivors of childhood cancer and for the establishment of registries of the late effects of pediatric oncology treatments. There is however little consensus about how this all should take place. For example, agreement on the nature of this follow up and the type of data to be collected in view of the earlier diagnosis and treatment of the patient is lacking. In a close collaboration between the 'Late Effects Study Group' (consisting of the Pediatric Oncology department of the Emma Children's Hospital and the department of Medical Oncology at the Academic Medical Center), the Netherlands Cancer institute/Antoni van Leeuwenhoek Hospital, and the department of Medical Informatics of the University of Amsterdam, consensus was reached on a new dataset on adverse late effects of pediatric oncology treatment. This dataset was used in developing an information model for the design of a computerized documentation system, PLEKsys. PLEKsys covers both standardized documentation of all relevant data items for evaluating late effects and review facilities on individual patient basis and on patient cohorts. We will install PLEKsys at all Dutch pediatric oncology centers and use the information model as a starting point in developing a National Pediatric Oncology Follow up Registry. A national programme encompassing all Dutch pediatric oncology centers has already been set up to co-ordinate the construction of this national registry.

Adult height and age at menarche in childhood cancer survivors

The aim of this study was to assess the long-term effects of cancer treatments on adult height and age at menarche in survivors of various types of childhood cancer. 285 childhood cancer survivors (161 men and 124 women), at least 18 years old and having been off treatment for at least 5 years, were examined. The effects of cranial (CrRT) and craniospinal irradiation (CrSpRT), other treatments and age at diagnosis on adult height and age at menarche were investigated. Patients who did not receive CrRT or CrSpRT, reached normal adult heights. However, a significant reduction in adult height was observed in men and women treated with CrRT or CrSpRT, especially if the treatment was given at the age of 8 years or younger. In girls, CrRT resulted in a significantly earlier menarche, compared with the Dutch population. Chemotherapy, radiation dose and age at menarche did not affect adult height. The relative risk (RR) of attaining an adult height below the 3rd percentile (20% 49/244) of the study population) was 6 times increased (RR=6.4; 95% confidence interval (CI) 1.46-28.52) after CrSpRT, 4 times (RR=4.2; 95% CI 1.81-9.63) after Crth and 5 times (RR=51; 95% CI 2.23-11.59) when irradiation was administered at the age of 8 years or younger. CrRT and CrSpRT and age at treatment are the main determinants of short stature in male and female childhood cancer survivors.

The level of prosaposin is decreased in the skin of patients with psoriasis vulgaris

Ceramides are the most abundant lipids constituting the intercellular matrix of the skin stratum corneum and their critical role in skin homeostasis has been extensively documented. Their concentration in the skin highly depends on the rate of availability of the enzymes involved in ceramide generation. The aim of this study was to investigate whether the concentration of prosaposin was altered in the skin of patients with psoriasis vulgaris. Prosaposin, the precursor of saposins (sphingolipid activator proteins), was measured in lesional and nonlesional skin of psoriatic patients and in normal skin from surgical patients, both at the mRNA and at the protein level. Densitometric analysis of reverse transcriptase-polymerase chain reaction bands separated by gel-electrophoresis showed a progressive decrease of prosaposin mRNA expression in nonlesional and lesional psoriatic skin, being substantially decreased in lesional psoriatic skin compared with normal control skin. Immunohistochemical analysis showed a significant decrease of prosaposin level in the stratum corneum of psoriatic lesional skin (both in active-type and in chronic-type plaque) compared with nonlesional and with normal skin (p < 0.01), and in psoriatic nonlesional skin compared with normal control (p < 0.05). Immunolocalization of sphingomyelinase in lesional and nonlesional psoriatic skin showed a decrease in the level of this enzyme in the stratum corneum of psoriatic lesional, compared with nonlesional skin. These results support the concept that disturbance of epidermal barrier function caused by derangement in ceramide generation can be crucial for the development of psoriatic skin diseases.

Enu mouse mutagenesis: generation of mouse mutants with aberrant plasma IgE levels

BACKGROUND

The ENU Mouse Mutagenesis Project aims at a large-scale, systematic production of mouse mutants using the alkylating agent ethyl-nitrosourea (ENU). Offspring of mutagenized mice are subjected to a multiparameter screen to detect alterations in various phenotypes with the ultimate goal of identifying novel genes relevant for the expression of the phenotype. Using this approach, we have analyzed plasma IgE concentrations to identify mouse mutants with aberrant plasma IgE levels.

METHODS AND RESULTS

ENU-mutagenized male C3HeB/FeJ were mated to wild-type females to produce F1 offspring. F1 animals were analyzed for alterations in their plasma IgE concentrations that showed a dominant mode of inheritance, or bred further to screen for recessive phenotypes. Plasma IgE concentrations were determined by ELISA and a normal range for plasma IgE was established using C3HeB/FeJ wild-type animals. So far we have tested 6568 F1 animals. Repeated testing confirmed a stable aberrant IgE phenotype in 124 animals. To confirm the genetic basis of the observed phenotype, these mice were subjected to confirmation crossing. Currently we have established 9 independent mutant mouse lines (3 with high plasma IgE and 6 with plasma IgE below detection limit) that have been genetically confirmed and additional 24 variant mouse lines are currently undergoing confirmation testing.

CONCLUSION

ENU mouse mutagenesis allowed us to generate and identify mouse mutants with aberrant plasma IgE levels, which may be used to characterize novel genes involved in IgE regulation and may serve as animal models for IgE-mediated diseases.

Atopic eczema and allergy

Although the pathomechanisms of respiratory atopy are well established, the role of IgE-mediated hypersensitivity in the elicitation and maintenance of eczematous skin lesions in atopic eczema (AE) is still controversial. There is, however, evidence for exogenous elicitation of AE by contact with aero- or food allergens (house dust mite, cat, and so forth). Recent investigations show that epidermal Langerhans' cells bind IgE via different receptors, especially the high-affinity receptor (Fc epsilon RI), which is significantly more strongly expressed in lesional skin of AE compared with other inflammatory skin diseases including allergic contact dermatitis. The clinical relevance of IgE-mediated sensitization in AE has been evaluated by the so-called atopy patch test (APT). The APT shows a much higher specificity compared with the skin prick test and radioallergosorbent test. However, allergic reactions do not play a decisive role in every case of AE. Other factors, such as nonspecific skin irritability or psychosomatic interactions, have to be considered. The concept of "extrinsic" versus "intrinsic" types of AE seems attractive. The concept of AE starting with TH2 inflammation, becoming TH1 inflammation in chronicity, and finally progressing to an autoimmune disease with IgE antibodies against autologous epidermal proteins is very attractive. Based on new knowledge, new methods in diagnosis, treatment, and prevention will develop, including more effective avoidance strategies, more potent anti-inflammatory treatment (e.g., immunomodulation or topical immunophyllins), and new ultraviolet modalities. The new findings have given rise to a possible new classification of eczema/dermatitis. The concept of "patient management," including all aspects from avoidance to therapy, has gained acceptance.

The role of fine-needle aspiration cytology in children with persistent or suspicious lymphadenopathy

PURPOSE

The aim of this study was (1) To determine the value of fine-needle aspiration cytology (FNAC) in children with persistent or suspicious peripheral lymphadenopathy and (2) to analyze whether a history of previous malignancy influenced the accuracy of FNAC.

METHODS

A retrospective study in an Academic Children's Hospital of 73 FNACs of peripheral lymph nodes in 64 patients (35 boys and 29 girls; median age, 9 years; range, 15 months to 20 years) was performed between 1992 and 1997. Eleven patients were excluded because aspirated material appeared inadequate. Outcome was compared with results of subsequent surgical biopsies, clinical follow-up, or both. Patients were divided into group A "de novo" lymphadenopathy (n = 39) and group B lymphadenopathy and a history of previous malignancy (n = 23).

RESULTS

Group A: FNAC showed a benign diagnosis in 25 cases, a malignancy in 13, and was inconclusive in 1. Outcome was false-negative in 2 and false-positive in 1. Sensitivity and specificity were 86% and 96%, respectively. FNAC helped avoid additional surgical procedures in 27 cases (61%). However, if FNAC showed malignant lymphoma, open biopsy was inevitable (8 of 13) to establish proper classification. Group B: FNAC showed a benign diagnosis in 10 cases and a malignancy in 13. Outcome was false-negative in 1, and false-positive in 1. Sensitivity and specificity were 92% and 90%, respectively. FNAC helped avoid additional surgical diagnostic procedures in 25 cases (86%).

CONCLUSIONS

(1) Fine-needle aspiration cytology is a rapid, simple and accurate diagnostic procedure to differentiate between benign and malignant peripheral lymphadenopathy in children. FNAC can avoid open biopsy in at least 60% of cases. (2) A history of previous malignant disease does not influence the accuracy of the test.

Secretion of proinflammatory eicosanoid-like substances precedes allergen release from pollen grains in the initiation of allergic sensitization

It is commonly believed that allergic sensitization starts when an allergen contacts the surface of an antigen-presenting cell in mucosal or skin epithelia. Most studies dealing with this aspect use allergen extracts as stimulus. Under natural exposure conditions, however, the bioavailability of allergen depends on allergen liberation from internal binding sites within the allergen carrier, e.g. pollen grains. In comparing total protein and major allergen release from timothy grass (Phleum pratense L.) pollen freshly collected on rural meadows or near high-traffic roads, there was a striking difference between the pollen, with higher allergen release rates from rural meadow pollen grains. Thus, allergen release does not explain the higher prevalence rates of atopic sensitization and disease observed in many epidemiological studies in children exposed to automobile exhaust. Therefore, other possible effectors from pollen grains were investigated. Pollen grains incubated in protein- free buffer were found to secrete significant amounts of eicosanoid-like substances, namely leukotriene (LT) B(4)-like and prostaglandin E(2)-like substances, in a pH-, time- and temperature-dependent fashion. The highest values of eicosanoid secretion were found in birch, grass and mugwort pollen, while pine (Pinus sylvestris L.) pollen showed only marginal eicosanoid-like secretion. Additionally, the release of these substances was significantly higher from pollen which had been collected near roads with heavy traffic, indicating a stronger proinflammatory activity of these pollen grains. In order to investigate the effects of air pollutants, native pollen grains were exposed in a dose- and time-dependent fashion in a fluidized bed reactor to traffic-related pollutants, e.g. volatile organic compounds (toluene, m-xylene), leading again to a significant increase in the secretion of LTB(4)-like immunoreactivity, in contrast to exposure with sulfur dioxide. This finding opens a new dimension of understanding of the early events in allergic sensitization, indicating that proinflammatory effects of the allergen carrier, e.g. the pollen grain itself, can lead to activation of the mucosal membrane. These findings might help to also explain the higher prevalence rates of pollen allergy in areas with high automobile exhaust emissions. Furthermore, the allergenic 'potency' of various allergens has to be redefined at the allergen carrier level with regard to different stages of allergen and mediator release prior to the contact with the host's immune system.

The interaction of human peripheral blood eosinophils with bacterial lipopolysaccharide is CD14 dependent

Bacterial lipopolysaccharide (LPS, endotoxin) is a ubiquitous component of dust and air pollution and is suspected to contribute after inhalation to an activation of eosinophils in bronchial tissues of asthmatic patients, provoking inflammatory and allergic processes. We were therefore interested in the interaction of eosinophil granulocytes with LPS and have examined the activation of and uptake to human peripheral blood eosinophils by LPS. Eosinophils were stimulated by LPS and the endotoxic component lipid A and the release of tumor necrosis factor alpha (TNF-alpha) and of the eosinophil-specific granule protein eosinophil cationic protein (ECP) was estimated. The results show induction of TNF-alpha and ECP-release by LPS and lipid A in a dose-dependent manner. Anti-CD14 monoclonal antibody (moAb) (clone MEM-18) and the synthetic lipid A partial structure 406 blocked the release of TNF-alpha and ECP by LPS-stimulated eosinophils. Studies with radioactively labeled LPS showed dose-dependent uptake of (3)H-LPS to eosinophils. The (3)H-LPS uptake was found to be specific because preincubation with unlabeled LPS, compound 406 and also anti-CD14 antibodies inhibited uptake of (3)H-LPS to eosinophil granulocytes. By flow cytometry using anti-CD14 moAb and by reverse transcriptase-polymerase chain reaction (RT-PCR) technique, CD14 expression was detectable. Furthermore, messenger RNA (mRNA) expression of Toll-like receptors (TLR) 2 and TLR 4 was detected, indicating the presence of these CD14 coreceptors. The results indicate that eosinophils can take up LPS and can be stimulated by LPS in a CD14-dependent manner. Hence, in addition to allergens, eosinophils interact with endotoxin, a process that possibly exacerbates ongoing inflammatory and allergic processes.

The excess of atopic eczema in East Germany is related to the intrinsic type

BACKGROUND

Prevalence data for atopic eczema based on a dermatological examination have not so far been available for East and West Germany. Possible differences in the proportions of extrinsic and intrinsic types of eczema, and how far these could explain differences in the prevalence of eczema, need to be clarified.

OBJECTIVES

To compare the prevalence of atopic eczema in pre-school children between different locations in East and West Germany, and over a period of 7 years, at three time points. Additionally, to determine the proportions of intrinsic and extrinsic types of eczema by taking skin prick test reactivity into account.

METHODS

Repeated cross-sectional studies in 1991, 1994 and 1997 in 5-6-year-old pre-school children at five different locations in West Germany (n = 2075) and six in East Germany (n = 1926) were carried out. Individuals with eczema were identified by an examination performed by physicians of the Department of Dermatology. In addition, a skin prick test and a standardized questionnaire were used.

RESULTS

The overall prevalence of atopic eczema in these children was 10.4%. At all three times of investigation (1991, 17.5% vs. 11.2%; 1994, 12.6% vs. 8.7%; 1997, 11.2% vs. 4.5%) and in the total group (12.9% vs. 8.2%), the prevalence was significantly higher in East than in West Germany. After controlling for influences of sex, parental history of atopic diseases, observer and socio-economic status in multiple logistic regression analyses, these differences remained significant for 1991, 1994 and for the overall group (odds ratio, OR 1.78, 95% confidence interval, CI 1. 43-2.21). Girls (OR 1.56, 95% CI 1.27-1.92) and children whose parents had a higher level of school education (OR 1.17, 95% CI 1. 00-1.37) were affected more frequently. Of all children, 26.6%, and of those with eczema, 41.9% exhibited at least one reaction in the prick test (OR 2.21, 95% CI 1.75-2.80; sensitization in eczema vs. no eczema). Whereas 50.4% of the children with eczema in West Germany were sensitized, only 36.5% of the diseased children in East Germany reacted positively in the prick test (OR 1.77, 95% CI 1.12-2. 79).

CONCLUSIONS

These results are in accordance with findings regarding allergic sensitization and hay fever and might indicate that factors other than allergy are responsible for the higher prevalence of atopic eczema in East Germany.

Genome-wide, large-scale production of mutant mice by ENU mutagenesis

In the post-genome era, the mouse will have a major role as a model system for functional genome analysis. This requires a large number of mutants similar to the collections available from other model organisms such as Drosophila melanogaster and Caenorhabditis elegans. Here we report on a systematic, genome-wide, mutagenesis screen in mice. As part of the German Human Genome Project, we have undertaken a large-scale ENU-mutagenesis screen for dominant mutations and a limited screen for recessive mutations. In screening over 14,000 mice for a large number of clinically relevant parameters, we recovered 182 mouse mutants for a variety of phenotypes. In addition, 247 variant mouse mutants are currently in genetic confirmation testing and will result in additional new mutant lines. This mutagenesis screen, along with the screen described in the accompanying paper, leads to a significant increase in the number of mouse models available to the scientific community. Our mutant lines are freely accessible to non-commercial users (for information, see http://www.gsf.de/ieg/groups/enu-mouse.html).

Identification of immunological relevant phenotypes in ENU mutagenized mice

The immunology screen focuses on the identification of novel gene products involved in the mammalian immune response and on the establishment of mouse models for immunological disorders. For this purpose, high throughput and semi-automated techniques were developed and optimized for low cost per sample and reproducibility. All assays are designed to be nonconsumptive and are based on peripheral blood or direct PCR amplification.

Parental sun protection management in preschool children

A total of 287 children (5 to 8 years old) were investigated for parental sun protection management techniques in a questionnaire-based survey. We evaluated the parents' knowledge about the risk of melanoma, their level of education, their nationality and the child's skin type with the children's use of sunscreen, clothes and shade. In general, the parents' knowledge about the correlation of skin cancer with extensive sun exposure in childhood was good. There was no correlation between the level of parental education and the frequency of sun protection measures. Children of non-German parents had significantly less sun protection. Our results indicate the need for special teaching programs for children in Germany to achieve a more responsible sun protection management.

Delayed craniospinal irradiation for a first isolated central nervous relapse of acute lymphoblastic leukemia: report on 14 cases

BACKGROUND

Children developing an isolated central nervous system (CNS) relapse as first recurrence of their acute lymphoblastic leukemia (ALL) are considered to have a systemic relapse as well. They are mostly treated with intensive chemotherapy and craniospinal irradiation. In most treatment schedules, irradiation is given early after induction treatment. Because craniospinal irradiation affects a large portion of hematopoietic bone marrow systemically, treatment is often delayed owing to aplasias. Also, dose reductions are frequently needed. Children receiving simultaneously irradiation and chemotherapy are prone to (often severe) neurotoxicity. This study reports on children with a first isolated CNS relapse of their ALL receiving chemotherapy for 40 weeks. Treatment ends with the administration of irradiation given after cessation of chemotherapy.

PROCEDURE

Fourteen children, with blasts and >5 cells/mm(3) in two consecutive samples of cerebrospinal fluid and a blast percentage <5% in their bone marrow were treated according to an intensive systemic and site-specific chemotherapy. Craniospinal irradiation was administered after cessation chemotherapy.

RESULTS

Event-free-survival was 57% (confidence interval 35-89%), freedom from relapse was 61.5%; follow-up ranges from 2.0 to 15.1 years (median 11.7 years). One child died from septicemia during induction. Five children experienced a second relapse and died from their malignancy. Two children [with a t(9;22) or a rearranged MLL gene] relapsed prior to radiotherapy. Outcome was related to duration of first remission, age at relapse, and identification as a high-risk patient at initial diagnosis. No neurologic complications were noted during and after treatment.

CONCLUSIONS

Delayed irradiation for isolated CNS relapse in children with ALL gives favorable survival rates, without significant toxicity. Neurotoxicity was absent.

Skin surface pH, stratum corneum hydration, trans-epidermal water loss and skin roughness related to atopic eczema and skin dryness in a population of primary school children

Non-invasive investigations of skin morphology and function are standard tools to study the pathophysiology of several cutaneous disorders, yet they have not been used in population-based epidemiological studies. Here we examined skin surface pH, stratum corneum hydration, trans-epidermal water loss (TEWL) and skin roughness by profilometry in a study population comprising 377 primary school children (8-9 years old) as part of a multicentre survey on risk factors for allergic diseases in school children. Skin surface pH showed significant higher values (p=0.029) in the group with atopic eczema (n=45) compared with the group without atopic eczema; all other parameters did not differ significantly between children with and without atopic eczema. With increasing skin dryness there was a significant increase in pH values (p=0.004). Stratum corneum hydration showed a significant decrease with increasing dryness (p<0.001). Measurement of skin roughness also revealed a significant linear relationship with skin dryness (p=0.02). It is concluded that measurement of skin surface pH, corneometry and profilometry are useful non-invasive techniques to objectively assess skin dryness in epidemiological studies regarding atopic skin disease.

Persistent mediastinal mass is not indicative of recurrence after chemotherapy only in paediatric Hodgkin's disease

Most patients with Hodgkin's disease are treated with chemotherapy in conjunction with radiotherapy, but at the end of treatment a residual mass is often present. After combined therapy, it has been assumed that no additional treatment is needed. However, for children treated without radiotherapy, no data exist on the relevance of a residual mediastinal mass to risk of relapse. We report on the findings of follow-up thorax radiographs of a group of 27 children with initial mediastinal involvement, who were treated with chemotherapy only. We conclude that the regression rate of the mediastinal mass was not related to a later recurrence. Regression after chemotherapy without radiotherapy is probably slower than after combined therapy. We consider chest radiograph examinations to be appropriate for the follow-up of tumour regression. When the data were compared with a group of children with Hodgkin's disease without mediastinal involvement, we found that survival was not related to initial mediastinal involvement.

[Eosinophilic cellulitis (Wells syndrome)]

Eosinophilic cellulitis (Wells' syndrome) is a rare disorder characterized clinically by recurrent erythematous plaques resembling cellulitis and histologically by a dermal infiltrate of lymphocytes, eosinophils and eosinophil debris between collagen bundles, forming flame figures in typical cases. A 71-year-old woman with Wells' syndrome with blood and bone marrow eosinophilia showed a good response to dapsone. The level of eosinophil cationic protein (ECP) in serum was elevated. Immunophenotyping of peripheral T cells revealed an increased proportion of CD3+CD4+T cells. The patients' cultured peripheral lymphocytes spontaneously released significant amounts of interleukin 5 (IL-5), but not interleukin 4 (IL-4) or interferon gamma (IFN gamma). These findings suggest that activated T cells may be involved in the pathogenesis of blood and tissue eosinophilia in this patient.

Traffic-related air pollution is associated with atopy in children living in urban areas

Traffic emissions are a major source of air pollution in Western industrialized countries. To investigate the association between traffic-related air pollution and parameters of atopy, we studied 317 children 9 years of age living near major roads in two urban areas and one suburban area of a city in West Germany. Atopic sensitization was analyzed by skin-prick testing and determination of allergen-specific serum immunoglobulin E. Parents recorded allergic symptoms in a symptom diary, and physicians assessed allergic diseases. Personal NO2 exposure and NO2 concentrations in front of each child's home were measured. Outdoor NO2 was a good predictor for traffic exposure but a poor predictor for NO2 exposure at the personal level. Atopy was found to be related to outdoor NO2 (odds ratio for the association between symptoms of allergic rhinitis and outdoor NO2 = 1.81; 95% confidence interval = 1.02-3.21) but not to personal NO2 (odds ratio for the association between symptoms of allergic rhinitis and personal NO2 = 0.99; 95% confidence interval = 0.55-1.79). When the analysis was restricted to urban areas, we found that hay fever, symptoms of allergic rhinitis, wheezing, sensitization against pollen, house dust mites or cats, and milk or eggs were associated with outdoor NO2. The results indicate that traffic-related air pollution leads to increased prevalence of atopic sensitizations, allergic symptoms, and diseases.