title: Clozapine-induced agranulocytosis in a Native American: HLA typing and further support for an immune-mediated mechanism.
abstract: BACKGROUND
  Approximately 30% of schizophrenic patients defined as treatment refractory significantly improve with clozapine. However, clozapine produces agranulocytosis in approximately 1% to 2% of patients in the United States. The mechanism of clozapine-induced agranulocytosis has not been established, but evidence suggests an immune-mediated mechanism.
  
  
  METHODS
  Human leukocyte antigen (HLA) typing was performed in a native American with clozapine-induced agranulocytosis.
  
  
  RESULTS
  Our findings support previous observations of a role of the HLA-B16, DR4, DQw3 haplotype in predicting susceptibility to agranulocytosis in clozapine-treated patients.
  
  
  CONCLUSIONS
  We suggest that HLA typing of clozapine candidates may be useful for predicting the risk for clozapine-induced agranulocytosis.
authors.affiliation: St. Paul Ramsey Medical Center, Department of Psychiatry, MN 55101-2595.
authors.forename: G M
authors.initials: GM
authors.lastname: Pfister
authors.forename: D R
authors.initials: DR
authors.lastname: Hanson
authors.forename: J L
authors.initials: JL
authors.lastname: Roerig
authors.forename: R
authors.initials: R
authors.lastname: Landbloom
authors.forename: M K
authors.initials: MK
authors.lastname: Popkin
mesh_terms: D000328:Adult; D000380:Agranulocytosis / Q000139:chemically induced* / Q000276:immunology; D003024:Clozapine / Q000009:adverse effects* / Q000276:immunology; D006680:HLA Antigens / Q000235:genetics / Q000276:immunology*; D015235:HLA-B Antigens / Q000276:immunology; D006683:HLA-DQ Antigens / Q000276:immunology; D015804:HLA-DR4 Antigen / Q000276:immunology; D006239:Haplotypes / Q000276:immunology; D006650:Histocompatibility Testing; D006801:Humans; D007198:Indians, North American / Q000235:genetics*; D008297:Male; D012307:Risk Factors
chemical_list: D006680:HLA Antigens; D015235:HLA-B Antigens; C049278:HLA-B16 antigen; D006683:HLA-DQ Antigens; C051569:HLA-DQ3 antigen; D015804:HLA-DR4 Antigen; D003024:Clozapine