Based on the previous discovery of STIM1 deficiency in a single family with a severe T cell immunodeficiency and the much higher risk of KS in individuals with acquired T cell deficiencies, we conclude that STIM1 T cell deficiency precipitated the development of lethal KS in this child upon infection with HHV-8.
These results demonstrate that IL-10 regulates T cell maturation and that dysregulation of IL-10 expression can lead to severe T cell immunodeficiency.