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. Issue 4 (2nd October 2021)

• Record Type: Journal Article
• Authors: Minato, Sonoko; Iijima, Hiroyuki; Nakao, Hiro; Nishi, Kentaro; Hidaka, Yoshihiko; Inoue, Norimitsu; Kubota, Mitsuru; Ishiguro, Akira
• Is Part Of: Immunological medicine. Volume 44:Issue 4(2021)
• Page Start: 274
• Page End: 277
• Publication Date: 2021-10-02
• Subjects: Atypical hemolytic uremic syndrome -- complement factor H -- systemic lupus erythematosus -- thrombotic microangiopathy; Immune System Phenomena; Immune System Diseases; Immunology -- Periodicals; Immunology; Periodical; Periodicals; Electronic journals; 571.96
• DOI: 10.1080/25785826.2021.1905303
• Languages: English
• ISSNs: 2578-5826

Abstract

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.