VH genes expressed in peripheral blood IgE-producing B cells from patients with atopic dermatitis.

In this study we analysed the VH genes expressed in IgE-producing peripheral B cells in two patients with severe atopic dermatitis. We found a diverse antibody repertoire containing V(H) genes of five different VH families, no VH2 and 7 genes, with no biased usage of one particular VH gene family. Some VH germ-line segments were found to be used several times within the epsilon transcripts (V3-23, V3-30). Comparison of the IgE-encoding VH genes with the respective germ-line elements revealed the expression of nearly germ-line identical as well as somatically mutated VH genes. In these latter VH genes base substitutions were distributed over both complementarity determining and framework regions. Because of the similarities between the IgE committed B cell repertoire in atopic patients and the peripheral B cell repertoire in non-atopic individuals we conclude that the atopic VH gene repertoire probably reflects the result of an increased class switch of polyclonal B cells, including virgin and mature B cells, in response to a Th2 cytokine profile.