A Patient with Post‐Hepatitis B Immune Deficiency: Nonspecific Helper Factor Partially Restores the in vitro Immune Response 1

Abstract. A patient with severe post‐hepatitis B aplastic anemia had depressed B and T cell responses. In mixed leukocyte culture, her cells were unresponsive to unrelated control stimulating cells, but responded well to a pool of cells from the same unrelated controls. She had reduced production of lymphocyte mitogenic factor (MF), suggesting a helper cell defect, and she had few or no cells reactive with the monoclonal anti‐T cell antibodies OKT3, OKT4 or OKT5. Her cells proliferated in response to MF produced by a pool of cells without mitogen, however. Furthermore, her cells became specifically cytotoxic when stimulated by cells plus MF, but not when stimulated by either cells or MF alone. Thus her T cell deficiency was correctable by nonspecific helper factor in vitro.