IgE, IgG and patient-self tests during slow hyposensitization to grass pollen

Twenty-two patients with severe hay fever unrelieved by antihistamines in previous years were slowly hyposensitized with alum-precipitated pyridine grass pollen extracts. Their responses were objectively assessed as very good (55%), good (18%) or improved (23%). Two mechanisms were detected: (i) an increase in serum blocking activity in 59% and (ii) the prevention in 59% of the serum IgE elevation expected in the pollen season.