A correlation between symptom severity and unbalanced reactive IgA production in Japanese cedar pollinosis patients

To better understand the unbalanced immunoglobulin production that occurs in pollinosis, we measured the levels of IgG, IgA, and IgE reactive to either Japanese cedar pollen, Cry j 1 protein, or Cry j 2 protein in the sera of pollinosis patients. As expected, the levels of these immunoglobulins (Igs) reactive to the three antigens were significantly higher in the patients than in the controls, and the RAST scores correlated with the levels of these Igs. Only the levels of IgA reactive to the Cry j 2 protein and IgG reactive to the Japanese cedar pollen antigen did not correlate with the RAST scores. We classified the patients into mild and severe, based on the severity of their allergic symptoms, and compared their levels of Igs. As expected, the levels of IgE reactive to Japanese cedar pollen and Cry j 1 of the severe group were significantly higher than those of the mild group. It is of note that the ratio of anti-Cry j 1 IgE to anti-Japanese cedar pollen IgA was significantly higher in the patients with severe symptoms suggesting that decreased IgA production could be responsible for the severity of pollinosis.