| Abstract: | ![]()
A patient with X-linked severe combined immunodeficiency (X-SCID) was found to have a deletion mutation of a four base pair in the transmembrane domain of the IL-2 receptor γ chain gene, a subunit shared by the receptors for IL-4, IL-7, IL-9, and IL-15 (common γ chain; γc). He had very few αβT cells but had a considerable number of γδT cells in his peripheral blood. Fluorescence in situ hybridization (FISH) analysis showed that the γδT cells in his peripheral blood were not of maternal origin. He had received a Bacillus Calmette-Guerin (BCG) vaccination before recognition of the disease, and the BCG infection remained quiescent with no reaction for 19 months. After successful bone marrow transplantation, the site of the BCG vaccination showed a reaction, and live BCG were detected. It is useful to consider the relationship between the existence of γδT cells and BCG in this case, and it is suggested that γδT cells may be, in a given situation, less dependent on the γc chain than are αβT cells. |
