The interferon‐α 2b gene in Japanese patients with chronic viral hepatitis who developed antibodies after treatment with recombinant interferon‐α 2a

DNA was extracted from leucocytes of 23 Japanese patients with chronic viral hepatitis who received treatment with recombinant interferon‐α 2a (IFN‐α 2a ) and nine healthy controls, as well as eight human cell lines of Caucasian or African origin. A part of the gene encoding IFN‐α 2 was amplified by polymerase chain reaction and the sequence of nucleotides 1–231 was determined. Interferon‐α 2a , ‐α 2b and ‐α 2c genes were tested for in five clones each from a patient or control, or a cell line, based on adenine or guanine at nucleotide positions 68 and 101. The IFN‐α 2b gene was detected in all 160 clones from 23 Japanese patients and nine controls, but the IFN‐α 2a or ‐α 2c gene was not found in any. Of five cell lines derived from Caucasians, four exhibited only the IFN‐α 2b gene, while the remaining one exhibited both IFN‐α 2a and ‐α 2b genes. Of three cell lines derived from Africans, one each showed only the IFN‐α 2b or ‐α 2c gene, and the remaining one both IFN‐α 2b and ‐α 2c genes. The 23 patients with the IFN‐α 2b gene and chronic viral hepatitis included 10 who developed antibodies against IFN after treatment with recombinant IFN‐α 2a . These results indicated a distinct geographical distribution of the three IFN‐α 2 genes, and suggested the use of a recombinant IFN‐α 2 preparation in agreement with the IFN‐α 2 gene possessed by the recipient to avoid antibody responses.