Clinical sensitivity to green algae demonstrated by nasal challenge and in vitro tests of immediate hypersensitivity

Abstract

Patients with symptoms of perennial allergic rhinitis have a high incidence of skin reactivity to various green algae, particularly to a Chlorella species isolated from unprocessed dust used in the commercial production of house dust extracts. Organ sensitivity to green algae in these patients was confirmed by a new nasal challenge procedure, the results of which correlated well with in vitro tests of Type I hypersensitivity. On the basis of such tests, patients with striking skin reactions could be differentiated into sensitive and nonsensitive groups. Those patients with skin sensitivity both to house dust and the Chlorella test species exhibited similar leukocyte, histamine release responses to these allergens. The discovery of an atopic population of patients who react clinically when challenged with both green algae and house dust reaffirms the role of algae as potentially important components of the indoor "ecosystem." Moreover, this population provides an experimental model for future investigation of the biomedical impact of algae in human hypersensitivity. © 1973.