To the Editor.
—The diagnosis of common variable immunodeficiency (CVI) is made by demonstrating the lack of the ability to generate new antibody responses or recall antibody responses against protein antigens, such as tetanus and diphtheria, coupled with low serum immunoglobulin levels and recurrent infections. It is interesting that in the cohort described by Dr Bresee and colleagues,1 26 of 29 immune-deficient patients (the bulk of whom appear to have CVI) who were documented to be positive for hepatitis C virus (HCV) nucleic acid were able to generate an antibody response against HCV proteins. Is there some special feature on the protein constituents of HCV that enables it to overcome the profound immune dysfunction characteristic of CVI?
Macy E. Hepatitis C Virus and Intravenous Immune Globulin. JAMA. 1997;277(8):627. doi:10.1001/jama.1997.03540320029022