Clozapine-induced agranulocytosis in a Native American: HLA typing and further support for an immune-mediated mechanism.
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.
Pfister
G M
GM
St. Paul Ramsey Medical Center, Department of Psychiatry, MN 55101-2595.
Hanson
D R
DR
Roerig
J L
JL
Landbloom
R
R
Popkin
M K
MK
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
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