Anti-complement factor H (CFH) antibodies and a novel CFH gene mutation in an atypical hemolytic uremic syndrome patient with complement activation of the classical pathway.
{"title":"Anti-complement factor H (CFH) antibodies and a novel <i>CFH</i> gene mutation in an atypical hemolytic uremic syndrome patient with complement activation of the classical pathway.","authors":"Sonoko Minato, Hiroyuki Iijima, Hiro Nakao, Kentaro Nishi, Yoshihiko Hidaka, Norimitsu Inoue, Mitsuru Kubota, Akira Ishiguro","doi":"10.1080/25785826.2021.1905303","DOIUrl":null,"url":null,"abstract":"<p><p>Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by overactivation of the complement alternative pathway. aHUS involves the presence of antibodies against complement factor H and its mutations in the complement genes. A 2-month-old boy presented with discoid rash, hemolytic anemia, thrombocytopenia, multiple antibodies, and hypocomplementemia with a very low level of C4 (< 3 mg/dL), indicating activation of the complement pathway, together fulfilling the systemic lupus erythematosus (SLE) criteria of the American College of Rheumatology at 5 months of age. However, most of these findings normalized spontaneously without any intervention. Further investigations revealed a high level of anti-complement factor H antibodies and a novel heterozygous missense mutation (p.Glu1172Ala, located in exon 22) in a complement gene, <i>CFH</i>. At 2 years of age, his SLE-like symptoms have not recurred, but hematuria and schistocytes were persistent. Eventually, aHUS was diagnosed rather than SLE. Our findings suggest that multiple antibody complex, including anti-complement factor H antibody, may temporarily activate the classical pathway, resulting in SLE-like findings.</p>","PeriodicalId":37286,"journal":{"name":"Immunological Medicine","volume":"44 4","pages":"274-277"},"PeriodicalIF":2.7000,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/25785826.2021.1905303","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Immunological Medicine","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1080/25785826.2021.1905303","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/3/30 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"IMMUNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare disease caused by overactivation of the complement alternative pathway. aHUS involves the presence of antibodies against complement factor H and its mutations in the complement genes. A 2-month-old boy presented with discoid rash, hemolytic anemia, thrombocytopenia, multiple antibodies, and hypocomplementemia with a very low level of C4 (< 3 mg/dL), indicating activation of the complement pathway, together fulfilling the systemic lupus erythematosus (SLE) criteria of the American College of Rheumatology at 5 months of age. However, most of these findings normalized spontaneously without any intervention. Further investigations revealed a high level of anti-complement factor H antibodies and a novel heterozygous missense mutation (p.Glu1172Ala, located in exon 22) in a complement gene, CFH. At 2 years of age, his SLE-like symptoms have not recurred, but hematuria and schistocytes were persistent. Eventually, aHUS was diagnosed rather than SLE. Our findings suggest that multiple antibody complex, including anti-complement factor H antibody, may temporarily activate the classical pathway, resulting in SLE-like findings.