Letter to the Editor
ADA2 deficiency complicated by EBV-driven lymphoproliferative disease

https://doi.org/10.1016/j.clim.2020.108443Get rights and content
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Highlights

  • We report a patient with ADA2 deficiency and EBV-driven lymphoproliferative disease.

  • ADA2 deficiency may predispose to severe EBV-induced disease.

  • We would recommend that EBV status and viral load is monitored in patients with ADA2 deficiency.

Abstract

A 29-year old male with recurrent respiratory and skin infections, anaemia and neutropaenia during childhood required immunoglobulin replacement for antibody deficiency from age 16. He remained relatively well until age 28 when he presented with a two-week history of fatigue, sore throat, fever and productive cough. He was found to have EBV viraemia and splenomegaly and a diagnosis of EBV-driven lymphoproliferative disease was made following bone marrow trephine. Family history was notable with three siblings: a healthy sister and two brothers with anaemia and neutropaenia; one who succumbed to septicaemia secondary to neutropaenic enterocolitis age 5 and another who developed intestinal vasculitis and antibody deficiency and had a successful haemopoetic stem cell transplant.

The proband's DNA underwent targeted sequencing of 279 genes associated with immunodeficiency (GRID panel). The best candidates were two ADA2 variants, p.Arg169Gln (R169Q) and p.Asn370Lys (N370K). Sanger sequencing and co-segregation of variants in the parents, unaffected sister and all three affected brothers was fully consistent with compound heterozygous inheritance. Subsequent whole genome sequencing of the proband identified no other potential causal variants. ADA2 activity was consistent with a diagnosis of ADA2 deficiency in affected family members.

This is the first description of EBV-driven lymphoproliferative disease in ADA2 deficiency. ADA2 deficiency may cause susceptibility to severe EBV-induced disease and we would recommend that EBV status and viral load is monitored in patients with this diagnosis and allogeneic SCT is considered at an early stage for patients whose ADA2 deficiency is associated with significant complications.

Keywords

ADA2
EBV
Lymphoproliferative disease
Immunodeficiency
Antibody deficiency
Viraemia

Abbreviations

ADA
Adenosine DeAminase
A2AR
Adenosine A2A receptor
CMV
Cytomegalovirus
CT
Computed Tomography
EBV
Epstein Barr Virus
GRID
Genomics of Rare Immune Disorders
PET
Positron Emission Tomography
RSV
Respiratory Syncytial Virus
SCID
Severe Combined ImmunoDeficiency
SCT
Stem Cell Transplant

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These authors have made an equal contribution.