SECRETORY IGA RESPONSE IN ORAL IMMUNOTHERAPY - INVESTIGATION IN BIRCHPOLLINOSIS

A rationale for oral immunotherapy (OIT) might be founded on two poten tial mechanisms: induction of a mucosal secretory IgA response, or ind uction of systemic hyporesponsiveness (oral tolerance). Previous studi es have shown clinically that there is a beneficial effect of OIT in b irch pollinosis, in both children and adults. During OIT, birch pollen antigens in enterocoated capsules were given to 20 adults (participat ing in a double-blind, placebo-controlled trial) and 10 children, all suffering from birch pollinosis. Saliva and tears (only adults) sample s were collected before, during, and after OIT. Each sample was assaye d for both IgA antibodies against birch pollen antigens and total IgA by enzyme-linked immunosorbent assay. IgA antibody levels were also ex pressed in relation to total IgA concentrations, to correct for variat ions in secretion and flow rate between subjects and at different time s. Changes in birch-specific secretory IgA antibodies in saliva and te ars could not explain the beneficial effect of OIT in birch pollinosis . Further studies in this field are warranted.