Systemic Vasculitis and High IgE Level in a Patient with LPS-Responsive Beige-Like Anchor (LRBA) Deficiency

Mutations in LPS-responsive and beige-like anchor (LRBA) gene in patients were firstly described to associate with a syndrome of immune deficiency and autoimmunity in 2012. However, there was still no LRBA deficient patient reported in China. We present a Chinese patient with heterozygous LRBA gene mutations with his clinical, immunological and genetic features. Patient’s clinical data was collected and analyzed. Laboratory results included lymphocyte subsets analysis and immunoglobulin quantification. Targeted gene capture followed by next-generation sequencing was used to identify the gene mutations, and flow cytometry assay was used to analyze B cell immunophenotyping of this patient. The patient mainly suffered from recurrent respiratory tract infections, EBV-associated lymphoproliferative disease and systemic vasculitis. Heterozygous LRBA gene mutations were identified in the patient, which were inherited from his parents, respectively. B cell immunophenotyping revealed that he had decreased total B cells, bone marrow progenitor B cell subsets (HSC, CLP, Pro-B and Pre-B cells), immature B cells, non-switched memory B cells, switched memory B cells and B1 cell subsets. Besides, he had extremely high level of IgE. Herein, we firstly report a patient with heterozygous LRBA gene mutations in China. LRBA might play an important role in B cell development.