MHC class Ⅱ-deficiency caused by CIITA gene mutation: A report of two cases and literature review

doi:10.19538/j.ek2018010615

Abstract：Objective To summarize and analyze the clinical characteristics,diagnosis and treatment of children with Major Histocompatibility Complex Class Ⅱ (MHC-Ⅱ) deficiency,in order to promote the awareness of this disease.Methods Retrospectively analyze the clinical features,immunological functions,protein expressions and genetic profiles of 2 children with MHC-Ⅱ deficiency identified from Children's Hospital of Fudan University,and discuss the method of diagnosis and treatment by reviewing related literatures.Results (1) Both of the patients were male and had a history of recurrent infection,and the age of onset was 4 years and 2 months,respectively;the age of diagnosis was 8 years and 3 months.Both had pulmonary infection;one had diarrhea and one was infected after BCG vaccination.Both were susceptible to fungi and virus,and even under the treatment of broad spectrum antibiotics and antifungal drugs,they were both dead from severe infection at the age of 8y and 3m,respectively.(2) One had neutropenia,two developed anemia,one had hypogammaglobulinemia,and both had severe CD4 T-cell lymphopenia.(3)Genetic analysis of CIITA showed that P1 had compound heterozygous mutations,with c.531C ＞ A mutation in exon 7 (inherited from father) and c.2408C ＞ A mutation in exon 11 (inherited from mother);P2 carried a homozygous nonsense mutation,with c.1161G ＞ A in exon 11 as well.(4)Due to severe infection,both patients failed to undergo the HSCT.Conclusion Patients with MHC Ⅱ deficiency usually experience early onset and are susceptible to various pathogens.Conventional anti-infection treatment is not effective for them.Early diagnosis and HSCT is the only effective way for them to survive;gene therapy is still in the research stage.