Clinical And Immunological Characteristics Of ILFS2 And Literature Review

Objective: In this study we investigated the clinical features,immunophenotype,diagnostic and therapeutic approach for child with recurrent acute liver failure which is caused by NBAS gene defects.In order to promote Chinese pediatricians' understanding of ILFS2,the case data reported in the global literature were summarized.This case is the fifth reported case of ILFS2 in China and the mutation site of p.[L2251Cfs*5] has not been reported before.Methods: We summarized and analyzed the clinical data of one case with fever-associated RALF.Characteristics of clinical,immunologic screening,high-throughput sequencing of immune-related genes,Pelger-Hu?t cells in the peripheral blood,proliferation of lymphocyte were analyzed by CFSE dilution method,and the function of NK cells were analyzed by CD107? transient expression flow cytometry in our patient.The related literature was searched by using search terms �NBAS'.Then summarized the clinical features,immunophenotypes,diagnosis and treatment methods of totally 22 cases of ILFS2 caused by NBAS gene defects which reported in the world.Results: The patient was a 5-year-old boy born in November 2012.At 1-2/12 years of age,he had a first fever accompanied by severe ALF.He presented several similar episodes in his life,always triggered by fever.Transaminases were significantly elevated which decreased during the control temperature,conventional liver protecting treatment and blood purification treatment.HE also had short stature and PHA.An immunologic evaluation showed low NK cell count.?1?A ILFS2 case was diagnosed.The gene sequencing showed NBAS gene c.[6751₆754delCTCC] and c.[3596-G>A] novel compound heterozygous mutations.Pelger-Hu?t cells exist in peripheral blood.The patient presented with lower NK count and cytotoxic index.B cell and T cell proliferation were normal.?2?A total of 4 literatures were enrolled for analysis,in which 22 patients with NBAS gene compound heterozygous mutation suffered recurrent acute liver failure.The phenotypic variability of the patients highlight that mutations in NBAS lead to a clinical spectrum ranging from isolated RALF to a multisystemic phenotype including short stature,hypotelorism,Pelger-Hu?t cells anomaly,skeletal dysplasia,chronic viral infection,reduced natural killer cells,hypogammaglobulinemia and so on.Conclusion: A case of ILFS2 was diagnosed by gene sequencing and immunophenotype analysis.A case of ILFS2 was diagnosed by us.The gene sequencing results showed NBAS gene c.[6751₆754delCTCC] and c.[3596-G>A] compound heterozygous mutations which inherited from his father and mother.And the mutation site of p.[L2251Cfs*5] has not been reported before.The patient presented lower NK count and cytotoxic index.Early and effective control of fever often allowed prevention of liver crises.