Exaggerated follicular helper T-cell responses in patients with LRBA deficiency caused by failure of CTLA4-mediated regulation

J Allergy Clin Immunol. 2018 Mar;141(3):1050-1059.e10. doi: 10.1016/j.jaci.2017.05.022. Epub 2017 Jun 7.


Background: LPS-responsive beige-like anchor protein (LRBA) and cytotoxic T lymphocyte-associated antigen 4 (CTLA4) deficiencies give rise to overlapping phenotypes of immune dysregulation and autoimmunity, with dramatically increased frequencies of circulating follicular helper T (cTFH) cells.

Objective: We sought to determine the mechanisms of cTFH cell dysregulation in patients with LRBA deficiency and the utility of monitoring cTFH cells as a correlate of clinical response to CTLA4-Ig therapy.

Methods: cTFH cells and other lymphocyte subpopulations were characterized. Functional analyses included in vitro follicular helper T (TFH) cell differentiation and cTFH/naive B-cell cocultures. Serum soluble IL-2 receptor α chain levels and in vitro immunoglobulin production by cultured B cells were quantified by using ELISA.

Results: cTFH cell frequencies in patients with LRBA or CTLA4 deficiency sharply decreased with CTLA4-Ig therapy in parallel with other markers of immune dysregulation, including soluble IL-2 receptor α chain, CD45RO+CD4+ effector T cells, and autoantibodies, and this was predictive of favorable clinical responses. cTFH cells in patients with LRBA deficiency were biased toward a TH1-like cell phenotype, which was partially reversed by CTLA4-Ig therapy. LRBA-sufficient but not LRBA-deficient regulatory T cells suppressed in vitro TFH cell differentiation in a CTLA4-dependent manner. LRBA-deficient TFH cells supported in vitro antibody production by naive LRBA-sufficient B cells.

Conclusions: cTFH cell dysregulation in patients with LRBA deficiency reflects impaired control of TFH cell differentiation because of profoundly decreased CTLA4 expression on regulatory T cells and probably contributes to autoimmunity in patients with this disease. Serial monitoring of cTFH cell frequencies is highly useful in gauging the clinical response of LRBA-deficient patients to CTLA4-Ig therapy.

Keywords: Autoantibodies; LPS-responsive beige-like anchor; cytotoxic T lymphocyte–associated antigen 4; follicular helper T cells; follicular regulatory T cells; regulatory T cells.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / deficiency*
  • Adaptor Proteins, Signal Transducing / immunology
  • CTLA-4 Antigen* / genetics
  • CTLA-4 Antigen* / immunology
  • Child
  • Female
  • Humans
  • Immune System Diseases* / genetics
  • Immune System Diseases* / immunology
  • Immune System Diseases* / pathology
  • Male
  • T-Lymphocytes, Helper-Inducer / immunology*
  • T-Lymphocytes, Helper-Inducer / pathology


  • Adaptor Proteins, Signal Transducing
  • CTLA-4 Antigen
  • CTLA4 protein, human
  • LRBA protein, human