Breakthroughs in the understanding and therapy of primary immunodeficiency

In the 40 years since Ogden Bruton discovered agammaglobulinemia, more than 50 additional immunodeficiency syndromes have been described. Until recently, there was little insight into the fundamental problems underlying a majority of these conditions. Recently, however, the molecular bases of three X-linked immunodeficiency disorders have been reported. These include X-linked immunodeficiency with hyper IgM, X-linked agammaglobulinemia, and X-linked severe combined immunodeficiency. These remarkable accomplishments have been made possible through a combination of new knowledge of molecular signaling mechanisms between and within cells of the immune system and greatly improved approaches to disease loci mapping within the human genome. Improvements in the therapy of immunodeficiency diseases have been impressive, and the development of generally safe and effective intravenous immunoglobulin preparations and T cell depletion techniques that permit the use of non-HLA-identical bone marrow donors have been the most important advances over the past 14 years. The identification and cloning of the genes for several of the primary immunodeficiency diseases have obvious implications for potential future somatic cell gene therapy for these patients. The rapidity of these advances suggests that soon there will be many more to come.