External quality assessment of HLA-B*5701 reporting: an international multicentre survey.

OBJECTIVES: HLA-B*5701 strongly predicts abacavir hypersensitivity (HSR), but implementation of effective routine screening into clinical practice requires testing be practical and accurate. We tested the proficiency of HLA-B*5701 typing among laboratories using sequence-specific primer PCR. DESIGN AND METHODS: DNA panels (1 and 2) were distributed to seven laboratories (A to G) for blinded typing of the HLA-B*5701 allele. Panel 1 (n = 10 samples; n = 7 laboratories) included 3 positives and other closely related B17 subtypes (B*5702, B*5703, B*5704 and B*5801). Panel 2 (n = 96 samples; n = 4 laboratories) included 36 positives among a broad spectrum of other B alleles. Two laboratories (A and B) also submitted 96 routine samples, typed by the same methodology, to the reference centre for additional analysis by sequence-based typing. RESULTS: All laboratories correctly typed panel 1 for HLA-B*5701 carriage. Laboratories A, B and C identified HLA-B*5701 alleles in panel 2 with 100% sensitivity and 100% specificity. Laboratory D reported one false negative, reportedly due to a sampling error. The results obtained for routine samples typed by laboratories A and B and those generated by the reference laboratory using sequencing were fully concordant. CONCLUSIONS: Detection of HLA-B*5701 alleles among laboratories was 100% specific and 99.4% sensitive, indicating that participating HIV testing laboratories were currently offering effective primary screening to identify individuals at high risk of abacavir HSR. Accurate reporting of HLA-B*5701 status is critical for the safe administration of this drug and participation in quality assurance programmes by all sites who report HLA-B*5701 status should be promoted.

Management of hereditary angioedema: a Canadian approach.

C1 esterase inhibitor (C1-INH) deficiency is a rare disorder that lacks consensus for diagnosis therapy and management. Recognizing that Canada is behind the European approach to this disorder, we have formed the Canadian Hereditary Angioedema Society (CHAES)/Société d'angioédème héréditaire du Canada (SAHC) to foster knowledge of this disorder in Canada and to advance care of patients with this disorder in Canada. We here present a review of treatment of this disorder in Canada including prevention of angioedema events and use of replacement therapy and present an algorithm for diagnosis therapy and management of C1-INH deficiency in Canada for discussion at our International Conference on Hereditary Angioedema to be held in Toronto, Canada, October 24th to 26th, 2003.