Abstract
Background Immune thrombocytopenia (ITP), autoimmune hemolytic
anemia (AIHA) and autoimmune neutropenia (AIN) are disorders
characterized by immune-mediated destruction of hematopoietic cell
lineages. A link between pediatric immune cytopenias and inborn errors
of immunity (IEI) was established in particular in the combined and
chronic forms.
Objective Identification of predictive factors of IEI in immune
cytopenic children is an important objective for a prompt immunological
diagnosis and appropriate management. Aim of this study is to detect
clinical and laboratory signs of IEI, in particular the latter by an
extensive lymphocyte immunophenotyping.
Methods We retrospectively collected 47 pediatric patients with
at least one hematological disorder among which persistent/chronic ITP,
AIHA and AIN, aged 0–18 years at onset of immune cytopenias and/or
immune-dysregulation. The cohort was divided into 2 groups (IEI+ and
IEI-), based on the presence/absence of underlying IEI diagnosis. IEI+
group, formed by 19/47 individuals, included: Common variable immune
deficiency (9/19), Autoimmune lymphoproliferative syndrome (4/19),
DiGeorge syndrome (1/19) and unclassified IEI (5/19).
Results IEI prevalence among patients with ITP, AIHA, AIN and
Evans Syndrome was respectively of 42%, 64%, 36% and 62%.
In IEI+ the extended lymphocyte immunophenotyping identified the
presence of statistically significant (p-value<0.05) specific
characteristics, namely T/B lymphopenia, decrease in naїve T-cells%,
switched memory B-cells%, plasmablasts% and/or immunoglobulins,
increase in effector/central memory T-cells% and CD21low B-cells%.
Conclusion A wide focused clinical/immunophenotypical
characterization of pediatric patients with immune cytopenia can
highlight specific signs of IEI, potentially helpful in the diagnostic
and clinical management, identifying children worthy of IEI-related
molecular analysis.
Keywords Immune cytopenias; Inborn errors of immunity; Immune
thrombocytopenia; Autoimmune hemolytic anemia; Autoimmune neutropenia;
Common variable immune deficiency; Autoimmune lymphoproliferative
syndrome, DiGeorge syndrome.