Clinical and Immunological Characterization of ICF Syndrome in Japan.

OBJECTIVE: Immunodeficiency, centromeric instability, and facial anomalies (ICF) syndrome is a rare autosomal recessive primary immunodeficiency. Hypogammaglobulinemia is a major manifestation of ICF syndrome, but immunoglobulin replacement therapy does not seem to be effective for some ICF patients. Therefore, we aimed to reassess the immunological characteristics of this syndrome. METHODS: Eleven Japanese patients with ICF syndrome were enrolled. We performed whole-exome sequencing in four cases and homozygosity mapping using SNP analysis in two. We evaluated their clinical manifestations and immunological status. RESULTS: We newly diagnosed six ICF patients who had tentatively been diagnosed with common variable immunodeficiency. We identified two novel mutations in the DNMT3B gene and one novel mutation in the ZBTB24 gene. All patients showed low serum IgG and/or IgG2 levels and were treated by periodic immunoglobulin replacement therapy. Three of the six patients showed worse results of the mitogen-induced lymphocyte proliferation test. Analyses of lymphocyte subpopulations revealed that CD19+CD27+ memory B cells were low in seven of nine patients, CD3+ T cells were low in three patients, CD4/8 ratio was inverted in five patients, CD31+ recent thymic emigrant cells were low in two patients, and CD19+ B cells were low in four patients compared with those in the normal controls. ICF2 patients showed lower proportions of CD19+ B cells and CD16+56+ NK cells and significantly higher proportions of CD3+ T cells than ICF1 patients. T cell receptor excision circles were undetectable in two patients. Despite being treated by immunoglobulin replacement therapy, three patients died of influenza virus, fatal viral infection with persistent Epstein-Barr virus infection, or JC virus infection. One of three dead patients showed normal intelligence with mild facial anomaly. Two patients presented with autoimmune or inflammatory manifestations. Infectious episodes decreased in three patients who were started on trimethoprim-sulfamethoxazole and/or antifungal drugs in addition to immunoglobulin replacement therapy. These patients might have suffered from T cell immunodeficiency. CONCLUSION: These results indicate that patients with ICF syndrome have a phenotype of combined immunodeficiency. Thus, to achieve a better prognosis, these patients should be treated as having combined immunodeficiency in addition to receiving immunoglobulin replacement therapy.

An eight-year-old girl with autoimmune polyglandular syndrome type3A that developed during the course of primary Epstein-Barr virus (EBV) infection: clinical implication of EBV in autoimmune thyroid disease.

An eight-year-old girl was admitted for prolonged fever and general fatigue. Bilateral reddened and swollen tonsils covered with white fur and increased numbers of atypical lymphocytes in blood led to a diagnosis of infectious mononucleosis (IM) due to primary Epstein-Barr virus (EBV) infection, which was confirmed by a positive anti-EBV viral capsid antigen IgM antibody reaction. She had a swollen thyroid gland and glycosuria at admission, which persisted after IM resolved. Undetectable thyroid-stimulating hormone (TSH), increased thyroid hormone and elevated HbA1c levels led to a diagnosis of autoimmune polyglandular syndrome type3A, based on the presence of antibodies for TSH receptor and glutamic acid decarboxylase. The clinical significance of EBV infection in the development of autoimmune endocrine disorders has been discussed.