title: A case of systemic amyloidosis associated with cyclic neutropenia.
abstract: Reactive AA amyloidosis is caused by the accumulation of the acute phase reactant, serum amyloid A (SAA), as a complication of chronic inflammatory conditions. Cyclic neutropenia is a rare hereditary disorder characterized by repeated episodes of neutropenia at regular intervals, with or without concurrent infection, and is known to be a rare cause of AA amyloidosis. Here, we report a case of a patient who developed systemic AA amyloidosis following a prolonged course of undiagnosed cyclic neutropenia. The patient had a history of recurrent infections since infancy and developed goiter, proteinuria, and azotemia at age 14 years. Her SAA level was markedly increased (601.8 μg/mL, normal range <8 μg/mL), and a thyroid and kidney biopsy revealed typical lesions of AA amyloidosis. Amyloid deposits were also detected in the myocardium, colon, and gallbladder. She had repeated episodes of neutropenia regularly at 3-week intervals and a pathogenic mutation in the ELA2 gene. After 10 months of treatment with recombinant human granulocyte colony-stimulating factor, her SAA level normalized (<2.5 μg/mL), but her renal function did not recover. This case clearly shows that cyclic neutropenia can be complicated by AA amyloidosis unless it is detected early and treated adequately.
authors.affiliation: Department of Pediatrics, Seoul National University Children's Hospital, 101 Daehang-no, Jongno-Gu, Seoul, 110-744, South Korea.
authors.forename: HyunKyung
authors.initials: H
authors.lastname: Lee
authors.forename: Kyoung Hee
authors.initials: KH
authors.lastname: Han
authors.forename: Yun Hye
authors.initials: YH
authors.lastname: Jung
authors.forename: Hee Gyung
authors.initials: HG
authors.lastname: Kang
authors.forename: Kyung Chul
authors.initials: KC
authors.lastname: Moon
authors.forename: Il Soo
authors.initials: IS
authors.lastname: Ha
authors.forename: Yong
authors.initials: Y
authors.lastname: Choi
authors.forename: Hae Il
authors.initials: HI
authors.lastname: Cheong
mesh_terms: D000293:Adolescent; D000686:Amyloidosis / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D019272:Leukocyte Elastase / Q000235:genetics; D009154:Mutation; D009503:Neutropenia / Q000150:complications / Q000235:genetics / Q000503:physiopathology
chemical_list: D019272:Leukocyte Elastase