title: Disappearance of inhibitor to factor IX in a patient with severe haemophilia B and immunological characterization of the inhibitor.
abstract: Disappearance of an inhibitor to factor IX in an 11-year-old boy with haemophilia B is described. He had been given a total of 14,200 units of a prothrombin complex concentrate (PCC) before an inhibitor to factor IX developed. He subsequently received four separate infusions of PCC and his inhibitor titre rose in response to the treatment for the following 4 years. No inhibitor is presently detected despite repeated administration of PCC. Immunological characterization of the inhibitor by inhibitor neutralization assays, modified crossed-immunoelectrophoresis and enzyme-linked immunosorbent assay demonstrated that it contained IgG2 and IgG4 heavy chains and kappa and lambda light chains. No large deletion of the factor IX gene in the patient was observed using cDNA (cVII).
authors.affiliation: Department of Pediatrics, Nara Medical College, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ohkubo
authors.forename: Y
authors.initials: Y
authors.lastname: Takahashi
authors.forename: M
authors.initials: M
authors.lastname: Sugimoto
authors.forename: M
authors.initials: M
authors.lastname: Nishino
authors.forename: T
authors.initials: T
authors.lastname: Nishimura
authors.forename: A
authors.initials: A
authors.lastname: Yoshioka
authors.forename: H
authors.initials: H
authors.lastname: Fukui
mesh_terms: D002648:Child; D004262:DNA Restriction Enzymes; D004797:Enzyme-Linked Immunosorbent Assay; D005164:Factor IX / Q000037:antagonists & inhibitors*; D002836:Hemophilia B / Q000097:blood*; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007123:Immunoelectrophoresis, Two-Dimensional; D008297:Male
chemical_list: D007106:Immune Sera; D005164:Factor IX; D004262:DNA Restriction Enzymes