concanavalin-a and Rhinitis--Allergic--Perennial

Blomia tropicalis, Dermatophagoides pteronyssinus and D. farinae are prevalent house dust mites. Concanavalin A-binding components derived from B. tropicalis (Bt-ConA extract) are highly immunogenic in allergic diseases. The aim of the present study was to evaluate the humoral and cellular immune responses to B. tropicalis in mite-sensitized patients. A total of 137 patients with allergic rhinitis with/without asthma and 109 non-atopic subjects were selected and analyzed by the skin prick test, and for total serum IgE and specific IgE levels to both Bt-total and Bt-ConA extracts, their proliferative response and cytokine (IFN-gamma and IL-5) production by peripheral blood mononuclear cells (PBMC) stimulated with both extracts. Skin prick test showed that 70% of the patients were sensitized to Bt (Bt+) and similar levels of specific IgE to Bt-total and Bt-ConA extracts were demonstrable in Bt+ patients. Significant PBMC proliferation was observed in response to Bt-total extract in Bt+, but not in Bt- patients and non-atopic subjects (P < 0.001). Bt-ConA extract induced increased proliferative responses in all patient groups compared to medium alone (P < 0.05), but these responses were significantly decreased in the presence of the mannopyranoside ConA inhibitor (P < 0.05). Significant IFN-gamma production was observed after Bt-ConA stimulation of Bt+ patients (P < 0.05), while Bt-total extract had no effect. IL-5 production was consistently detected in Bt+ patients after allergen-specific stimulation or with no stimulus, indicating that PBMC from allergic patients are prone to produce Th2 profile cytokines, spontaneously or inductively by allergen restimulation. These data showed that ConA-binding components isolated from B. tropicalis may contain relevant antigens that are involved in both humoral and cellular immune responses. However, without an additional purification procedure to eliminate the residual contamination with ConA, its use in immunotherapeutic procedures cannot be recommended.

Topics: Adult; Allergens; Animals; Antigens, Dermatophagoides; Antigens, Plant; Case-Control Studies; Cell Proliferation; Concanavalin A; Desensitization, Immunologic; Female; Humans; Immunoglobulin E; Interferon-gamma; Interleukin-5; Leukocytes, Mononuclear; Male; Mites; Mitogens; Rhinitis, Allergic, Perennial

Blomia tropicalis (Bt) and Dermatophagoides pteronyssinus (Dp) are the prevalent house dust mites in tropical countries and are associated with allergic diseases. Glycosylated antigens are highly immunogenic and involved in different pathologies. We evaluated the presence of IgE, IgG1, and IgG4 to concanavalin A-binding antigens (Bt-Con-A) isolated from Bt-total extract in sera of allergic and non-allergic subjects. Bt-total and Bt-Con-A extracts were evaluated by SDS-PAGE and ELISA for reacting with IgE, IgG1, and IgG4 in sera of 121 patients with allergic rhinitis and 36 non-allergic individuals. All subjects were skin prick tested with Bt-total extract and inhibition tests were performed for IgE, IgG1, and IgG4 using both extracts (Bt-total and Bt-Con-A). Skin prick test showed that 58% of the patients were sensitized to Bt (Bt+), with 52% reactive to both mites (Bt and Dp) and 6% to Bt only. A broad spectrum of proteins (14-152 kDa) was visualized in Bt-total and components >27 kDa for the Bt-Con-A extract. ELISA showed a similar profile of IgE, IgG1 and IgG4 levels in response to Bt-total and Bt-Con-A extracts in different groups, although Bt+ patients showed a lower IgG4 reactivity to Bt-Con-A extract. Specific IgG1 levels were higher in Bt+ patients than in control subjects, and IgG4 levels showed no significant difference among groups. ELISA inhibition showed a partial IgE and total IgG1 and IgG4 cross-reactivity with Dp extract for Bt-total and Bt-Con-A extracts. We conclude that Con-A-binding components isolated from Bt constitute major allergens and are involved in both allergen sensitization (IgE response) and homeostasis maintenance (IgG1 and IgG4 responses).

Topics: Allergens; Animals; Antibody Specificity; Antigens, Dermatophagoides; Antigens, Plant; Autoantibodies; Case-Control Studies; Concanavalin A; Cross Reactions; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin E; Immunoglobulin G; Mites; Rhinitis, Allergic, Perennial; Severity of Illness Index

Observing the basophil releasability of 17 patients with allergic rhinitis and 14 nonatopic subjects stimulated with house dust mite and concanavalin A (ConA), we found that the histamine release was much higher in patients with allergic rhinitis than in normal controls and that no positive correlation was found between the histamine release rate and the serum total IgE. This result suggests that the enhanced basophil releasability might be an important factor in allergic disorders, and might contribute to a means for the differentiation between allergic and non-allergic disorders.

Topics: Adult; Animals; Basophils; Concanavalin A; Female; Histamine Release; Humans; Immunoglobulin E; Male; Middle Aged; Mites; Rhinitis, Allergic, Perennial

To evaluate the specificity of the lymphocyte transformation test (LTT) in the diagnosis of drug allergy we studied over 71 days an atopic woman with a past history of frequent adverse reactions to pyrazolone drugs. Rechallenge with the incriminated substances aminophenazone (aminopyrine) and propyphenazone was carried out on Days 11 and 31 respectively. An immediate type of hypersensitivity reaction was seen after 100 mg aminophenazone, while 100 mg of propyphanozone led to a serum sickness-like syndrome. We found two specifically sensitized lymphocyte populations using either the pure substance or sera containing metabolite in cell cultures. Stimulatory responses with indices ranging between 3 and 6 were seen 3-4 days after exposure, and the tests remained positive in both instances for 3-4 weeks. Specific sensitization was proven by positive skin tests and by a small but distinct lymphocyte proliferative response before challenge. Several lymphocyte function tests were performed over a period of 53 days and revealed a large fall in pokeweed mitogen-induced immunoglobulin synthesis and an increase in suppressor cell activity after rechallenge with aminophenazone. We conclude that the proliferative response observed in the presence of the offending drug is due to the activation of T memory cells and therefore highly suggestive of a true allergic reaction.

Topics: Adult; Aminopyrine; Anti-Inflammatory Agents, Non-Steroidal; Antipyrine; Concanavalin A; Drug Hypersensitivity; Humans; Immunoglobulin G; Lymphocyte Activation; Male; Mitogens; Pyrazoles; Rhinitis, Allergic, Perennial; Time Factors

Concanavalin A (Con A)-induced suppressor action against the proliferative response of autologous lymphocytes to phytohemagglutinin (PHA) was examined in the peripheral blood lymphocytes of 32 patients with bronchial asthma, 10 patients with allergic rhinitis and then compared with 12 simultaneously studied healthy normals. Twenty-two of 32 patients (68.8%) with bronchial asthma, 8 of 10 patients (80%) with allergic rhinitis demonstrated deficient Con-A-induced suppressor function. Abnormal suppressor cell functions could play an important role in the pathogenesis of respiratory allergic states.

Topics: Adolescent; Adult; Asthma; Child; Child, Preschool; Concanavalin A; Female; Humans; Immunoglobulin E; Male; Middle Aged; Rhinitis, Allergic, Perennial; T-Lymphocytes, Regulatory