Frontiers in Immunology (May 2019)

Paradoxical CD4 Lymphopenia in Autoimmune Lymphoproliferative Syndrome (ALPS)

  • Andrea Lisco,
  • Chun-Shu Wong,
  • Susan Price,
  • Peiying Ye,
  • Julie Niemela,
  • Megan Anderson,
  • Elizabeth Richards,
  • Maura Manion,
  • Harry Mystakelis,
  • Morgan Similuk,
  • Bernice Lo,
  • Jennifer Stoddard,
  • Sergio Rosenzweig,
  • Christophe Vanpouille,
  • Adam Rupert,
  • Irina Maric,
  • Ainhoa Perez-Diez,
  • David Parenti,
  • Peter D. Burbelo,
  • V. Koneti Rao,
  • Irini Sereti

DOI
https://doi.org/10.3389/fimmu.2019.01193
Journal volume & issue
Vol. 10

Abstract

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Autoimmune lymphoproliferative syndrome (ALPS) is caused by germline or somatic loss of function FAS mutations resulting in impaired apoptosis and consequent expansion of T-lymphocytes causing organomegaly and autoimmune anemia, neutropenia and thrombocytopenia. Herein, we report on a case of disseminated varicella zoster infection after post-partum vaccination in a patient found to have CD4 lymphopenia and eventually diagnosed with ALPS caused by a novel germline missense mutation in FAS death-domain. A subsequent retrospective analysis of 169 patients of the NIH ALPS-FAS cohort, revealed that CD4-T-cells lymphopenia (< 300 cells/μl) may occur in 5% of ALPS-FAS patients irrespectively of the underlying genetic defect, organomegaly or immunosuppressive treatment. Although immunophenotyping did not show depletion of specific CD4-T-cells subpopulations, CD4-lymphopenic ALPS-FAS subjects had an expansion of a subset of circulating T-follicular-helper (cTfh) cells, associated with autoantibody production (CCR7lowPD-1high). Furthermore, autoantibodies binding on CD4-T-cells were detected in 50% of the CD4-lymphopenic ALPS-FAS patients and caused cytotoxicity in a natural killer (NK)-mediated antibody-dependent-cellular cytotoxicity assay. Such autoantibodies can therefore be associated with CD4-T-cell death, impaired activation induced proliferation or impaired trafficking. The expansion of autoreactive T-cells in ALPS-FAS is known to be associated with autoimmune clinical manifestations, however our study reveals that ALPS-FAS can also be associated with a paradoxical depletion of CD4-T-cells due to the presence of autoantibodies on the surface of CD4-T-cells which can in turn result in increased susceptibility to opportunistic infections. These novel findings have implications for the diagnosis, clinical monitoring, and management of patients with ALPS-FAS.

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