title: Paroxysmal nocturnal hemoglobinuria in systemic lupus erythematosus: a case report.
abstract: BACKGROUND
  Paroxysmal nocturnal hemoglobinuria is an acquired disorder of hemopoiesis and is characterized by recurrent episodes of intravascular hemolysis due to an increased sensitivity to complement-mediated hemolysis. Systemic lupus erythematosus with paroxysmal nocturnal hemoglobinuria is very rare. We report a case of paroxysmal nocturnal hemoglobinuria that developed in a patient with systemic lupus erythematosus and lupus nephritis.
  
  
  METHODS
  A 29-year-old Mongolian woman had systemic lupus erythematosus, which manifested only as skin lesions when she was 12 years old. She had leg edema and proteinuria when she was 23 years old, and a renal biopsy revealed lupus nephritis (World Health Organization type IV). She had been treated with steroids and immunosuppressant therapy. At 29, she had headaches, nausea, general fatigue, and severe pancytopenia and was admitted to our hospital. A laboratory evaluation showed hemolytic anemia. Further examination showed a neutrophil alkaline phosphatase score of 46 points, a CD55 value of 18%, and a CD59 value of 78.6%. The results of Ham test and sugar water tests were positive. The constellation of symptoms throughout the clinical course and the laboratory findings suggested paroxysmal nocturnal hemoglobinuria.
  
  
  CONCLUSIONS
  To the best of our knowledge, systemic lupus erythematosus with paroxysmal nocturnal hemoglobinuria is very rare. Clinicians should be aware of the association between autoimmune and hematological diseases.
authors.affiliation: Community Medicine, Hirosaki University Graduate School of Medicine, 5 Zaifu-cho, Hirosaki-city, Aomori, 036-8562, Japan. nnakamur@r2.dion.ne.jp.
authors.forename: Norio
authors.initials: N
authors.lastname: Nakamura
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Sugawara
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Shirato
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Kumasaka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakamura
authors.forename: Michiko
authors.initials: M
authors.lastname: Shimada
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujita
authors.forename: Reiichi
authors.initials: R
authors.lastname: Murakami
authors.forename: Yuko
authors.initials: Y
authors.lastname: Shimaya
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Osawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yamabe
authors.forename: Ken
authors.initials: K
authors.lastname: Okumura
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