Aspects of the pathological significance of IgG4.

Depending on the circumstances, an IgG4 antibody response could have consequences which are either detrimental or beneficial for health. Because of its role in allergic disease and its modulatory effect on other immunoglobulin classes (IgE in particular) and subclasses, IgG4 will continue to be the subject of intensive research. There is, however, an urgent need to develop reagents which would render the detection of IgG4 variants 'a' and 'b' routine, so that their biological and antibody characteristics could be understood.