Stimulation of human peripheral blood lymphocytes with chironomid hemoglobin allergen (Chi t I)

A review on Respiratory allergy caused by insects

Hypersensitivity or allergy encompasses a wide range of immunological reactions that generally have adverse consequences involving one or many organ systems of the body. Allergens are usually glycoprotein or chemically complex low molecular weight substances. The common allergens include pollen, fungal spores, house dust mite and house dust, animal danders, drugs, foods, insect emanations, and detritus, etc. Information on the role of insects in respiratory allergy is increasing in the literature. There are about 30 million living species of insects. These insects can broadly be classified as stinging insects, biting insects and non-stinging and non-biting insects. All materials form insets namely wings, scales, saliva; dried feces and venom can cause allergic diseases, such as rhinitis, conjunctivitis, asthma and urticaria. There are wide varieties of insects such as moths, butterflies, bees, wasps, hornets, yellow jackets, flies, beetles, cockroaches, and mosquitoes. Exposure to emanations and detritus of these insects may lead to several allergies in some genetically predisposed individuals. Therefore, it is of interest to review allergies caused by various insect's stings and bites and their adverse effect on the human body.

Association of class II sequences encoding DR1 and DQ5 specificities with hypersensitivity to chironomid allergen Chi t I

A panel of 188 unrelated Caucasian subjects who were exposed to the larvae of Chironomus thummi (Diptera, nonbiting midges) was HLA-typed by polymerase chain reaction amplification of the second exons of the DRB, DQA1, and DQB1 genes followed by dot-blot hybridization with sequence-specific oligonucleotide probes. Type I sensitization to the allergen Chi t I and a large number of other inhalant allergens was determined by RAST and skin testing. Sixty-one individuals were found to be sensitized to Chi t I, of whom 24 were sensitive to this allergen and to no other allergens tested. Statistical analyses showed that only in the latter group were the HLA-D genes DRB1*0101, DQA1*0101, and DQB1*0501 associated with IgE-responsiveness to Chi t I. These results suggest that HLA associations with responsiveness to certain allergens may be more striking in monosensitized subjects.

Allergen-induced expression of cell surface markers on lymphocytes of Chi t I-sensitized patients

Lymphocyte cultures of persons sensitized to the hemoglobin allergen Chi t I show a highly significant response to the allergen measured in the lymphocyte stimulation assay by (3H)-thymidine uptake. In this study, we investigated by flow cytometry the expression of different cell surface markers on lymphocytes after in vitro stimulation for 7 d with or without the allergen Chi t I. We determined the expression of the low-affinity receptor for IgE (CD23) on lymphocytes of Chi t I-sensitized patients and Chi t I-exposed as well as nonexposed controls. CD23 expression was significantly higher in patients than in nonexposed controls. Exposed but healthy subjects showed intermediate values. We also determined the expression of activation markers CD25 (IL-2 receptor) and HLA-DR on the lymphocytes of patients and nonexposed controls. HLA-DR expression on non-T cells (CD3-) was significantly higher in patients than in controls. HLA-DR on T cells (CD3+), and CD25 as well as CD23 expression, could be significantly enhanced after antigen-specific stimulation in patients but not in controls, whereas alpha/beta-T-cell-receptor expression was significantly reduced in patients. Differences between patients and controls were not observed in response to tetanus toxoid (TT) and phytohemagglutinin (PHA). Our results demonstrate antigen-specific influences on the expression of cell surface molecules. These findings may be valuable diagnostic information.

Humoral immune response to the insect allergen Chi t I in aquarists and fish-food factory workers

Our examination of 225 subjects who had been exposed to the insect allergen Chi t I involved the degree of allergen exposure, the exposure-associated symptoms, and their relationship to the presence of specific IgE and IgG antibodies as well as sensitization to ubiquitous allergens. It could be shown that specific IgE antibodies found in 34% of these subjects were closely associated with symptoms (P < 0.01), whereas no relationship between IgG antibodies and complaints could be observed. Conjunctivitis (63%) and rhinitis (62%) were predominant, followed by asthma (45%) and urticaria (37%). Antibody levels of patients suffering from asthma were highest. In addition, symptoms were associated with the degree of exposure. While nearly all IgE-sensitized subjects of the medium-, high-, and very high-exposure group were symptomatic, only 57% of the sensitized individuals of the low-exposure group reported complaints. Furthermore, specific IgE antibodies were most frequently present in the groups with medium (46%) and high (54.5%) exposure, whereas IgG antibodies predominated in individuals with very high exposure (69.1%). In the low-exposure group, most subjects (73.6%) had neither IgE nor IgG antibodies. In addition, within Chi t I sensitized subjects, sensitization to common allergens and elevated total IgE levels were more frequently present than within non-Chi t I sensitized individuals, indicating a predisposition to allergy.