mu-Chain gene expression in common variable immunodeficiency.

Three patients with common variable immunodeficiency (CVID) were analyzed for translation from mu mRNA by the cell-free translation method and for expression of mu mRNA by northern blotting. In cases 1 and 2, the mu chain was not detected in the products by cell-free translation nor was mu mRNA detected by northern blotting. In case 3, mu mRNA was detected at a low level. This suggests that the disorders occur between rearrangement of the Ig genes and transcription of the C mu gene in cases 1 and 2, and that the functions of rearrangement and transcription are qualitatively preserved to a certain degree in case 3. Thus, the pathogeneses of CVID are variable and more research on regulatory mechanisms of B cell development is necessary to understand each case of CVID.