Comprehensive review of autoantibodies in patients with hyper-IgM syndrome

摘要

Hyper-immunoglobulin M syndrome is an X-linked primary immunodeficiency disease caused by mutations in the CD40 ligand gene.The CD40 ligand has been recently highlighted as playing a key role in the pathogenesis of primary biliary cholangitis.In the present study,we assessed an extensive set of serum autoantibodies in a series of well-defined patients with hyper-immunoglobulin M syndrome.Serum,liver-related and liver-not-related autoantibodies IgG,IgM and IgA were tested by ELISA and standard indirect immunofluorescence in HEp-2 cells in 13 Tunisian patients(8 males and 5 females,aged 1–12 years)with hyper-immunoglobulin M syndrome during 1995–2012 and,as controls,21 age-and gender-matched blood donors.The level of IgM antibody against MIT3 was significantly higher in patients than in controls(35.8 vs 10.7,P=0.002).Half of the hyperimmunoglobulin M syndrome patients were found to be anti-MIT3 IgM positive vs none of the controls(Po0.0001).Twenty-three percent of patients were found to be anti-sp100 antibody positive vs only 0.05%of controls.By immunofluorescence,92.3%of patients were MIT3 IgM positive vs none of the controls.In conclusion,the IgM class of anti-MIT3 antibodies was shown to be present by both ELISA and immunofluorescence in most of the patients with hyper-immunoglobulin M syndrome.The presence of the hallmark of primary biliary cholangitis,a disease where the CD40 ligand is a key player,in an immunodeficiency disease caused by mutations in the CD40 ligand gene is very intriguing and opens new scenarios in understanding the immune pathogenesis of primary biliary cholangitis.