IgG subclasses in nonallergic children chronic chest symptoms with

Immunoglobulin and IgG subclass measurements were made on sera from 37 children thought to have asthma whose chronic chest symptoms were unexplained by allergy. There was a higher proportion of low or low-normal levels of lgG subclasses 1, 2, and 4 in these children than in normal children. Those who had low serum lgG values on initial measurement had a higher proportion of low or low-normal levels of IgG1, IgG2, and lgG4; those who had normal IgG values had a higher proportion of low or low-normal levels of lgG2 and IgG4. Thus a normal serum concentration of lgG did not exclude the possibility of an abnormal level of IgG2 or lgG4. Our experience suggests that abnormal levels of lgG subclasses might play an etiologic role in the chronic chest symptoms in some of these children. (J PEDtATR 105:896, 1984)