Multinational assessment of absolute neutrophil counts and white blood cell counts among healthy Duffy-null adults

S Stephen P. Hibbs (1Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom) I Israel Chipare (2Blood Transfusion Service of Namibia, Windhoek, Namibia) A Amr J. Halawani (3Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Umm Al-Qura University, Mecca, Saudi Arabia) S Sophie E. Legge G Geoffrey Fell (5Department of Data Science, Dana-Farber Cancer Institute, Boston, MA) D Daniel Dees (6Department of Pathology, Brigham and Women's Hospital, Boston, MA) D David J. Roberts (7NHS Blood and Transplant, Oxford, United Kingdom) N Nicholas Gleadall (10Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom) O Olga Shamardina (10Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom) A Abdulrahman A. Alhamzi (12Department of Blood Bank, King Fahad Central Hospital, Jazan, Saudi Arabia) E Edwig Shingenge (13Department of Clinical Health Sciences, Namibia University of Science and Technology, Windhoek, Namibia) M Mohammed J. Alabdly (12Department of Blood Bank, King Fahad Central Hospital, Jazan, Saudi Arabia) H Hilary T. Charuma (2Blood Transfusion Service of Namibia, Windhoek, Namibia) M Mohammed A. Nushaily (12Department of Blood Bank, King Fahad Central Hospital, Jazan, Saudi Arabia) J Judith M. Sinvula (2Blood Transfusion Service of Namibia, Windhoek, Namibia) M Menelik Russo (13Department of Clinical Health Sciences, Namibia University of Science and Technology, Windhoek, Namibia) M Michelle Sholzberg (14Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada) S Sara Paparini (1Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom) V Vanessa Apea (1Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom) M Maureen Okam Achebe (17Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Boston, MA) N Nancy Berliner (1Department of Hematology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA) L Lauren E. Merz (18Division of Hematology/Oncology, Mass General Brigham, Boston, MA)

Abstract

Abstract Laboratory reference intervals must reflect population diversity for accurate medical decisions. The Duffy-null variant lowers absolute neutrophil counts (ANC), but existing dedicated reference intervals are based on a single African American cohort. The impact across other ethnic groups and regions remains unclear, and no white blood cell count (WBC) intervals exist for Duffy-null individuals. This study aimed to establish and compare Duffy-null ANC and WBC reference intervals across 4 continents. A cross-sectional study was conducted assessing healthy Duffy-null individuals from dedicated cohorts (blood donors in Namibia, Saudi Arabia, and the United Kingdom; primary care patients in the United States) and biobanks (participants from the United Kingdom and the United States). Among 8018 participants (880 from dedicated cohorts and 7138 from biobanks), novel ANC and WBC reference intervals were established (Namibia [ANC, 820/μL to 6370/μL; WBC, 2.51 × 109/L to 9.85 × 109/L]; Saudi Arabia [ANC, 1140/μL to 5290/μL; WBC, 3.72 × 109/L to 10.71 × 109/L]; United Kingdom (ANC, 1185/μL to 5462/μL; WBC, 3.1 × 109/L to 8.8 × 109/L]; the United States [ANC, 1210/μL to 5390/μL; WBC, 3.00 × 109/L to 9.66 × 109/L]), with no significant differences between cohorts. Institutional reference intervals misclassified 27.9% (Namibia), 50.9% (Saudi Arabia), 26.0% (United Kingdom), and 21.7% (the United States) as neutropenic. Biobank analyses confirmed no significant difference in ANC between Black and non-Black Duffy-null participants. Duffy-null individuals consistently exhibit lower ANC and WBC across ethnic groups and regions. Current reference intervals overlook this variation, risking misdiagnosis and health inequities. Implementing Duffy-specific reference intervals is essential for equitable and accurate clinical decisions worldwide.

Article Details

Journal Blood
Volume / Issue Vol. 147, Issue 3
Published January 15, 2026
Pages 290-298
ISSN 0006-4971
Publisher Elsevier BV

Journal Info

Blood

Elsevier BV

ISSN: 0006-4971 Health Sciences

Authors (22)

S

Stephen P. Hibbs

1Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom

I

Israel Chipare

2Blood Transfusion Service of Namibia, Windhoek, Namibia

A

Amr J. Halawani

3Department of Clinical Laboratory Sciences, Faculty of Applied Medical Sciences, Umm Al-Qura University, Mecca, Saudi Arabia

S

Sophie E. Legge

G

Geoffrey Fell

5Department of Data Science, Dana-Farber Cancer Institute, Boston, MA

D

Daniel Dees

6Department of Pathology, Brigham and Women's Hospital, Boston, MA

D

David J. Roberts

7NHS Blood and Transplant, Oxford, United Kingdom

N

Nicholas Gleadall

10Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom

O

Olga Shamardina

10Department of Haematology, University of Cambridge, Cambridge Biomedical Campus, Cambridge, United Kingdom

A

Abdulrahman A. Alhamzi

12Department of Blood Bank, King Fahad Central Hospital, Jazan, Saudi Arabia

E

Edwig Shingenge

13Department of Clinical Health Sciences, Namibia University of Science and Technology, Windhoek, Namibia

M

Mohammed J. Alabdly

12Department of Blood Bank, King Fahad Central Hospital, Jazan, Saudi Arabia

H

Hilary T. Charuma

2Blood Transfusion Service of Namibia, Windhoek, Namibia

M

Mohammed A. Nushaily

12Department of Blood Bank, King Fahad Central Hospital, Jazan, Saudi Arabia

J

Judith M. Sinvula

2Blood Transfusion Service of Namibia, Windhoek, Namibia

M

Menelik Russo

13Department of Clinical Health Sciences, Namibia University of Science and Technology, Windhoek, Namibia

M

Michelle Sholzberg

14Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada

S

Sara Paparini

1Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom

V

Vanessa Apea

1Wolfson Institute of Population Health, Queen Mary University of London, London, United Kingdom

M

Maureen Okam Achebe

17Division of Hematology, Department of Medicine, Brigham and Women's Hospital, Boston, MA

N

Nancy Berliner

1Department of Hematology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA

L

Lauren E. Merz

18Division of Hematology/Oncology, Mass General Brigham, Boston, MA