ASH sets blood count reference ranges for Duffy-null people

The American Society of Hematology (ASH) has published reference ranges for absolute neutrophil count (ANC) and white blood cell count (WBC) in children and adults with Duffy-null status. The release was distributed via EurekAlert on 5 November 2026. The ranges appeared in Blood Advances and are described as the first of their kind. eurekalert.org

Duffy-null status is a common genetic trait associated with naturally lower circulating white blood cell counts. According to the release, it affects more than 66% of people with African or Mediterranean ancestry in the US. eurekalert.org

Under standard reference ranges, people with Duffy-null status may be flagged as having neutropenia, an abnormally low white blood cell count. The authors say this can lead to unnecessary testing such as bone marrow biopsies, exclusion from clinical trials, or discontinuation of necessary therapies such as chemotherapy. eurekalert.org

Why the counts differ

The Duffy antigen is a protein on red blood cells. In Duffy-null individuals it is naturally absent, and its absence protects against infection with malaria parasites. eurekalert.org

The antigen also affects the distribution of neutrophils, the most common type of white blood cell. Without it, more neutrophils are concentrated in tissues and fewer circulate in the blood, where samples for laboratory tests are drawn. As a result, measured counts are lower than in Duffy-positive people. eurekalert.org

Ranges from 1,412 samples

Researchers at 23 US sites collected 1,412 samples from Duffy-null individuals. They used the samples to validate adult ranges and to collect the first data for pediatric ranges across four age categories. eurekalert.org

For adults, ANC is 1.03 to 7.30×10⁹/L and WBC is 3.0 to 10.7×10⁹/L. For children aged 6 months to 2 years, ANC is 0.53 to 4.50×10⁹/L and WBC is 4.4 to 12.6×10⁹/L. For ages 3 to 6 years, ANC is 0.78 to 4.67×10⁹/L and WBC is 3.8 to 10.8×10⁹/L. eurekalert.org

For ages 7 to 12 years, ANC is 0.87 to 5.34×10⁹/L and WBC is 2.9 to 10.1×10⁹/L. For ages 13 to 17 years, ANC is 0.90 to 4.89×10⁹/L and WBC is 3.1 to 9.2×10⁹/L. eurekalert.org

Collection strategies and patient populations differed between sites, but the authors report no meaningful differences in the ranges once these factors were accounted for. Reference intervals for children under 6 months old require further research. eurekalert.org

The study is part of the ANC by Duffy Status Project, an ASH initiative supported by the Doris Duke Foundation. ASH also published a study in Blood Advances showing that universal pediatric testing for the Duffy-null variant is cost effective. eurekalert.org

ASH publishes first neutrophil and white cell reference ranges for Duffy-null children and adults

Why the counts differ

Ranges from 1,412 samples

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