Increased proportions of γδ T lymphocytes in atypical SCID associate with disease manifestations

Clin Immunol. 2019 Apr;201:30-34. doi: 10.1016/j.clim.2018.11.006. Epub 2019 Feb 15.


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 γδ T lymphocytes have been reported. However, it is unknown whether these γδ T cells modulate or reflect the patient's clinical phenotype. We investigated the frequency of elevated γδ T cell proportions and associations with clinical disease manifestations in a cohort of 76 atypical SCID patients. Increased proportions of γδ T lymphocytes were present in approximately 60% of these patients. Furthermore, we identified positive correlations between elevated proportions of γδ T cells and the occurrence of CMV infections and autoimmune cytopenias. We discuss that CMV infections might trigger an expansion of γδ T lymphocytes, which could drive the development of autoimmune cytopenias. We advocate that atypical SCID patients should be screened for elevated proportions of γδ T lymphocytes, CMV infection and autoimmune cytopenias.

Keywords: Atypical SCID; Autoimmune cytopenia; CMV infection; Lymphopenia; Viral infection; γδ T lymphocytes.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cytomegalovirus Infections / immunology*
  • Hematologic Diseases / immunology*
  • Humans
  • Intraepithelial Lymphocytes / immunology*
  • Lymphocyte Count
  • Severe Combined Immunodeficiency / immunology*

Supplementary concepts

  • Severe combined immunodeficiency, atypical