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

Background: 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. Objectives: We present a Chinese patient with heterozygous LRBA gene mutations with his clinical, immunological and genetic features. Methods: 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. Results: 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. Conclusions: Herein, we firstly report a patient with heterozygous LRBA gene mutations in China. LRBA might play an important role in B cell development.