Is the diagnostic rate for the common subtypes of A1AT deficiency consistent across two Canadian Provinces?

Mathew P Estey; Tania Tahooni; Tanya N Nelson; Michelle L Parker; Terence A Agbor; Hui-Min Yang; Rachel Jen; Vilte E Barakauskas; Grace Y Lam; Allison Matthews; Andre Mattman

doi:10.1016/j.clinbiochem.2021.05.002

Is the diagnostic rate for the common subtypes of A1AT deficiency consistent across two Canadian Provinces?

Clin Biochem. 2021 Sep:95:84-88. doi: 10.1016/j.clinbiochem.2021.05.002. Epub 2021 May 6.

Authors

Affiliations

¹ DynaLIFE Medical Labs, 200, 10150 102 St, Edmonton, AB T5J 5E2, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.02 Walter C. Mackenzie Health Sciences Centre, Edmonton, AB T6G 2R7, Canada. Electronic address: mathew.estey@dynalife.ca.
² Department of Pathology and Laboratory Medicine, St Paul's Hospital, 1081 Burrard St, Vancouver, BC V6Z 1Y6, Canada.
³ Department of Pathology and Laboratory Medicine, BC Children's & BC Women's Hospitals, Children's and Women's Health Centre of British Columbia, 4480 Oak Street, Room 2J10, Vancouver, BC V6H 3V4, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Rm. G227 - 2211 Westbrook Mall, Vancouver, BC V6T 2B5, Canada. Electronic address: tnelson@cw.bc.ca.
⁴ DynaLIFE Medical Labs, 200, 10150 102 St, Edmonton, AB T5J 5E2, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.02 Walter C. Mackenzie Health Sciences Centre, Edmonton, AB T6G 2R7, Canada. Electronic address: michelle.parker@dynalife.ca.
⁵ DynaLIFE Medical Labs, 200, 10150 102 St, Edmonton, AB T5J 5E2, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, 5B4.02 Walter C. Mackenzie Health Sciences Centre, Edmonton, AB T6G 2R7, Canada. Electronic address: terence.agbor@dynalife.ca.
⁶ Department of Pathology and Laboratory Medicine, University of British Columbia, Rm. G227 - 2211 Westbrook Mall, Vancouver, BC V6T 2B5, Canada; Department of Pathology and Laboratory Medicine, Vancouver General Hospital, 910 W 10th Ave., Vancouver, BC V5Z 1M9, Canada.
⁷ Department of Medicine, Division of Respiratory Medicine, University of British Columbia, 7th Floor, 2775 Laurel Street, BC V5Z 1M9, Canada; Department of Medicine, Division of Pulmonary Medicine, University of Alberta, 11302 83 Ave NW, Edmonton, AB T6G 2G3, Canada.
⁸ Department of Pathology and Laboratory Medicine, BC Children's & BC Women's Hospitals, Children's and Women's Health Centre of British Columbia, 4480 Oak Street, Room 2J10, Vancouver, BC V6H 3V4, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Rm. G227 - 2211 Westbrook Mall, Vancouver, BC V6T 2B5, Canada. Electronic address: vilte.barakauskas@cw.bc.ca.
⁹ Department of Medicine, Division of Pulmonary Medicine, University of Alberta, 11302 83 Ave NW, Edmonton, AB T6G 2G3, Canada. Electronic address: glam@ualberta.ca.
¹⁰ Department of Pathology and Laboratory Medicine, BC Children's & BC Women's Hospitals, Children's and Women's Health Centre of British Columbia, 4480 Oak Street, Room 2J10, Vancouver, BC V6H 3V4, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Rm. G227 - 2211 Westbrook Mall, Vancouver, BC V6T 2B5, Canada.
¹¹ Department of Pathology and Laboratory Medicine, St Paul's Hospital, 1081 Burrard St, Vancouver, BC V6Z 1Y6, Canada; Department of Pathology and Laboratory Medicine, University of British Columbia, Rm. G227 - 2211 Westbrook Mall, Vancouver, BC V6T 2B5, Canada. Electronic address: amattman@providencehealth.bc.ca.

PMID: 33964271
DOI: 10.1016/j.clinbiochem.2021.05.002

Abstract

Background: The diagnosis of alpha-1-antitrypsin (A1AT) deficiency has been hindered by obscurity concerning the testing process and treatment implications. In this study, we aimed to identify regional differences in the diagnostic rates for A1AT deficiency in the western Canadian provinces of British Columbia (BC) and Alberta (AB).

Methods: The number of A1AT deficiency variant genotype (ZZ, SZ, MZ, SS, and MS) diagnoses were reviewed for BC and AB. The regional diagnostic rates for A1AT deficiency variants in these two provinces, normalized for the predicted population prevalence of each variant genotype, was defined as the annual provincial diagnostic rate (APDR) for a given variant genotype. Sex specific variations in the mean age at diagnosis for the five variant genotypes were compared both within and between provinces.

Results: The SZ and MZ genotype APDRs were significantly increased in the AB population compared to the BC population. The SS and MS APDRs were similar between AB and BC. There was a significantly decreased mean age of diagnosis for AB males, as compared to BC males (for the SZ, MS, and MZ genotypes) and as compared to AB females (for the MS, MZ, and SS genotypes). There were no significant differences in the mean age of diagnosis between the females and males in BC, or between females in AB and BC, for any genotype.

Conclusion: The notably higher APDR for more severe A1AT deficiency genotypes, and lower mean age of diagnosis for most variant genotypes in AB males, deserves further investigation to determine the explanation(s) for these differences.

Keywords: A1AT deficiency; Canada; Delayed diagnosis; Diagnostic rates; Regional.

Publication types

Case Reports

MeSH terms

Age Factors
Alberta / epidemiology
British Columbia / epidemiology
Female
Genotype
Humans
Male
Middle Aged
Retrospective Studies
Sex Factors
alpha 1-Antitrypsin / blood
alpha 1-Antitrypsin / genetics*
alpha 1-Antitrypsin Deficiency / blood
alpha 1-Antitrypsin Deficiency / diagnosis*
alpha 1-Antitrypsin Deficiency / genetics*

Substances

SERPINA1 protein, human
alpha 1-Antitrypsin