Increased proportions of gamma delta T lymphocytes in atypical SCID associate with disease manifestations
Abstract
Severe combined immunodeficiencies (SCID) comprise a group of genetic diseases characterized by abrogated development of T lymphocytes. In some case reports of atypical SCID patients elevated proportions of gamma delta T lymphocytes have been reported.
However, it is unknown whether these gamma delta T cells modulate or reflect the patient's clinical phenotype. We investigated the frequency of elevated gamma delta T cell proportions and associations with clinical disease manifestations in a cohort of 76 atypical SCID patients.
Increased proportions of gamma delta T lymphocytes were present in approximately 600/0 of these patients. Furthermore, we identified positive correlations between elevated proportions of gamma delta T cells and the occurrence of CMV infections and autoimmune cytopenias.
We discuss that CMV infections might trigger an expansion of gamma delta T lymphocytes, which could drive the development of autoimmune cytopenias. We advocate that atypical SCID patients should be screened for elevated proportions of gamma delta T lymphocytes, CMV infection and autoimmune cytopenias.