Effect of environmental intervention on mouse allergen levels in homes of inner-city Boston children with asthma.

BACKGROUND: Recent studies have suggested that mouse allergen exposure and sensitization are common in urban children with asthma. The effectiveness of environmental intervention in reducing mouse allergen exposure has not been established. OBJECTIVE: To evaluate whether environmental intervention of mouse extermination and cleaning results in a reduction in mouse allergen levels. METHODS: Eighteen homes of children with positive mouse allergen skin test results and at least mild persistent asthma in urban Boston, MA, with evidence of mouse infestation or exposure were randomized in a 2:1 ratio (12 intervention and 6 control homes). The intervention homes received an integrated pest management intervention, which consisted of filling holes with copper mesh, vacuuming and cleaning, and using low-toxicity pesticides and traps. Dust samples were collected and analyzed for major mouse allergen (Mus m 1) and cockroach allergen (Bla g 1) at baseline and 1, 3, and 5 months after the intervention was started and compared with control homes. RESULTS: Mouse allergen levels were significantly decreased compared with control homes by the end of the intervention period at month 5 in the kitchen and bedroom (kitchen intervention, 78.8% reduction; control, 319% increase; P = .02; bedroom intervention, 77.3% reduction; control, 358% increase; P < .01; and living room intervention, 67.6% reduction; control, 32% reduction; P = .07). CONCLUSIONS: Mouse allergen levels were significantly reduced during a 5-month period using an integrated pest management intervention.

A patient with severe black fly (Simuliidae) hypersensitivity referred for evaluation of suspected immunodeficiency.

BACKGROUND: Biting flies of the Diptera order and specifically the black fly (Simuliidae family) can be rare causes of severe hypersensitivity reactions. OBJECTIVE: To describe a patient referred for evaluation of immunodeficiency whose clinical course is explained by severe Simuliidae hypersensitivity. METHODS: The patient's immune system was investigated using standard laboratory evaluations. Hypersensitivity to Simuliidae was pursued because of historical features of her presentation and was specifically examined by skin prick and intradermal testing with whole body extract. RESULTS: The patient's history was notable for recurrent and severe seasonal episodes of presumed cellulitis after black fly bites that responded poorly to intravenous antibiotics. One episode was followed by acute inflammatory demyelinating polyneuropathy (Guillain-Barré syndrome) and another by minimal change nephrotic syndrome. The results of immunologic investigations were unremarkable, but cutaneous hypersensitivity to Simuliidae was demonstrated with a 6.5-mm wheel and 35-mm flare reaction to intradermal injection of only 0.0005 microg of whole body extract. CONCLUSION: Similar to Hymenoptera, Simuliidae can rarely result in extreme hypersensitivity and should be considered in appropriate cases. This patient illustrates how severe reactions toinsect bites can be misdiagnosed.

Conformational changes in env oligomer induced by an antibody dependent on the V3 loop base.

OBJECTIVE: The HIV-1 env oligomer is structured such that conserved, neutralizing epitopes are obscured by gp120 variable loops. We have studied the ability of an IgG2 human monoclonal antibody (hmAb), F425 B4e8 (B4e8), dependent upon the base of the V3 loop, to induce conformational changes in the env oligomer. DESIGN: The effect of B4e8 antibody on the exposure of neutralizing epitopes and viral neutralization was studied in combination with other hmAb. METHODS: Epitope exposure and viral neutralization was determined using native, intact primary isolate virions. RESULTS: B4e8 antibody neutralizes infection and binds to HIV-infected cells and primary isolate virions. B4e8 and 2G12 enhanced the binding of each other to infected cells or virus and the combination resulted in synergistic neutralization. B4e8 also enhanced the binding of CD4i and CD4 binding site antibodies. CONCLUSIONS: The conserved epitopes exposed by B4e8 are similar to those exposed by the movement of the variable loops following CD4 engagement. Further studies with select antibody combinations should provide important information for the design of effective immunotherapeutic agents.