title: Activated phosphoinositide 3-kinase δ syndrome presenting with gut-associated T-cell lymphoproliferative disease.
abstract: A 13-year-old boy was admitted to our hospital because of persistent diarrhea, abdominal pain, and bloody stools. The patient had experienced repeated hospitalizations for the treatment of respiratory infections since early childhood. Colonoscopic and pathological studies led to a diagnosis of gut-associated T-cell lymphoproliferative disease (T-cell LPD). Laboratory data showed T-lymphocytopenia (492/µl), increased serum IgG levels (1,984 mg/dl), and low serum antibody titers for specific pathogens. Combined immunodeficiency accompanied by T-LPD suggested the diagnosis of activated PI3Kδ syndrome (APDS). Genetic analyses identified a heterozygous mutation of the PIK3CD gene (c.1573 G to A p.Glu525Lys). Although prednisolone and cyclosporine therapy has controlled the T-cell LPD, this patient awaits allogeneic hematopoietic cell transplantation to achieve a complete cure of his APDS.
authors.affiliation: Department of Pediatrics, Graduate School of Medical Sciences, Kyushu University.
authors.forename: Hideto
authors.initials: H
authors.lastname: Teranishi
authors.forename: Masataka
authors.initials: M
authors.lastname: Ishimura
authors.forename: Yuuki
authors.initials: Y
authors.lastname: Koga
authors.forename: Katsuhide
authors.initials: K
authors.lastname: Eguchi
authors.forename: Motoshi
authors.initials: M
authors.lastname: Sonoda
authors.forename: Tetsuko
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Satoru
authors.initials: S
authors.lastname: Shiraishi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Nakashima
authors.forename: Kouji
authors.initials: K
authors.lastname: Ikegami
authors.forename: Murasaki
authors.initials: M
authors.lastname: Aman
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Takada
authors.forename: Shouichi
authors.initials: S
authors.lastname: Ohga
mesh_terms: D000293:Adolescent; D058534:Class I Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D003108:Colonic Diseases / Q000000981:diagnostic imaging* / Q000235:genetics; D004789:Enzyme Activation; D006801:Humans; D008232:Lymphoproliferative Disorders / Q000000981:diagnostic imaging* / Q000235:genetics; D008297:Male; D000072078:Positron Emission Tomography Computed Tomography; D013601:T-Lymphocytes
chemical_list: D058534:Class I Phosphatidylinositol 3-Kinases; C486018:PIK3CD protein, human