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Diversity, Equity, and Inclusion in Health Care

Absolute Neutrophil Count (ANC) by Duffy Status Project

The American Society of Hematology (ASH) is at the forefront of addressing a critical health equity concern through its groundbreaking initiative - the Reconsideration of Absolute Neutrophil Count (ANC) Reference Ranges by Duffy Status.

The initiative is funded by a grant from the Doris Duke Foundation and seeks to ensure that all individuals, especially those with Duffy-null Associated Neutrophil Count (DANC), receive optimal care by redefining ANC reference ranges based on Duffy status. The overarching effort is structured as a multifaceted approach targeting health care systems, health care professionals, clinical trialists and their funding sources, and patients. The proposed project would lead to a better understanding of the impact of Duffy-null status and its implications for clinical decision-making.

Join ASH in this important endeavor to redefine ANC reference ranges and improve health care equity for all. Together, we can make a lasting impact on the lives of individuals with DANC.

Approximately two of three people identifying as Black in the U.S. are expected to have the Duffy null phenotype. Of note, race and ethnicity are not biological facts but sociopolitical constructs. Genetic traits do not obey racial boundaries or geographic constructs, so using them as proxies requires extreme caution. While the Duffy null phenotype is not exclusive to African or Arabian Peninsula genetic ancestry, it is most commonly found among these populations.

Explore the latest publication in Blood Advances.


Aim 1: Empower Health Care Systems (HCS)

Collaborate with select Health Care Systems to validate new adult and pediatric ANC reference ranges based on Duffy status.

Aim 2: Educate Health Care Professionals

Raise awareness about Duffy-null Associated Neutrophil Count (DANC) among practicing physicians, clinicians, administrators, and educators.

Aim 3: Begin Interventions on a Systems Level

Directly impact the lives of individuals with DANC by advocating for the adoption of Duffy testing and supporting the application of new ANC threshold ranges in clinical trials.

Health Care Systems

Listed below are the selected cohort healthcare systems.

  • Atrium Health Carolinas Medical Center
  • Banner MD Anderson Cancer Center
  • Boston Medical Center
  • Children’s Hospital of Philadelphia
  • Children’s National Hospital
  • Icahn School of Medicine at Mount Sinai
  • Johns Hopkins University
  • Mayo Clinic
  • MD Anderson Cancer Center
  • Montefiore Health System
  • Nemours Children’s Hospital
  • NewYork-Presbyterian/Weill Cornell Medical Center
  • Northwestern University
  • Norton Cancer Institute
  • Rhode Island Hospital
  • Saint Peter’s University Hospital
  • St. Jude Children's Research Hospital
  • University of North Carolina at Chapel Hill
  • University of Alabama at Birmingham
  • University of California, Los Angeles
  • University of Connecticut
  • University of Illinois Chicago
  • University of Michigan
  • Vanderbilt University Medical Center

Frequently Asked Questions

Reference ranges are intended to identify the central 95% of healthy populations. However, some laboratory values can vary among different populations like von Willebrand factor by blood type.

Another example is found the Duffy null phenotype and absolute neutrophil counts (ANC). Approximately two in three people in the United States who have African or Middle Eastern genetic ancestry have the Duffy-null phenotype. This results in a clinically insignificant lower ANC compared to the commonly used reference population which is often established from individuals of Asian or European descent of whom nearly 100% are Duffy non-null.

Thus, individuals with the Duffy null phenotype have no increased risk of infection but are often incorrectly labeled as having neutropenia. This can result in unnecessary, expensive, and invasive testing, delayed or discontinued chemotherapy or other critical medications, exclusion from clinical trials, and other negative consequences.


ASH has partnered with the Doris Duke Charitable Foundation and has funding available to help with the development and dissemination of Duffy-null specific reference ranges. This funding is intended to cover the costs of Duffy typing and ANC testing and patient recruitment as well as some support for the time from physicians, laboratory techs, and/or research assistants required to complete this project.

This project will attempt to validate adult reference ranges from previously published values which requires approximately 40-60 Duffy null samples. It will also attempt to establish new pediatric reference ranges which require 120 Duffy null samples per age category.

Health Care systems can opt to participate in adults only, pediatrics only, or both.

There are multiple possible methods to obtain samples from healthy populations that are outlined in the draft protocols in order to match preferences and realities of each individual institution. Samples must be collected from healthy participants. However, residual blood or fresh blood can be used. Any setting where there is a density of healthy participants is acceptable. Duffy phenotyping or genotyping are both acceptable, and institutions can type samples in-house or through send-out. All institutions involved must participate in a central IRB. De-identified limited demographic data, Duffy typing, and ANC values will be submitted at regular intervals to RedCap Cloud throughout the project.


  • Type 1 diabetes, rheumatoid arthritis, psoriasis, multiple sclerosis, systemic lupus erythematosus, inflammatory bowel disease, Addison’s disease, Graves’ disease, Hashimoto thyroiditis, Myasthenia gravis, Sjogren’s syndrome, pernicious anemia, autoimmune vasculitis, celiac disease, autoimmune hepatitis, vitiligo, immune thrombocytopenia, dermatomyositis.


  • Any primary immunodeficiency including chronic granulomatous disease, common variable immunodeficiency, Chediak-Higashi syndrome, cyclic neutropenia, leukocyte adhesion defects, or congenital neutropenia. Any individual with previous assessment for or diagnosis of neutropenia of any kind.


  • Hepatitis C infection, hepatitis B infection, HIV. Any active acute infection.


  • Type 1 diabetes, rheumatoid arthritis, psoriasis, multiple sclerosis, systemic lupus erythematosus, inflammatory bowel disease, Addison’s disease, Graves’ disease, Hashimoto thyroiditis, Myasthenia gravis, Sjogren’s syndrome, pernicious anemia, autoimmune vasculitis, celiac disease, autoimmune hepatitis, vitiligo, immune thrombocytopenia, dermatomyositis.


  • Any malignant neoplasm or hematological cancer including ductal carcinoma in situ, intraductal papillary mucinous neoplasm, or MGUS


  • Any history of receiving organ transplant or skin graft including history of allogenic or autologous hematopoietic stem cell transplant


  • Sickle cell disease (any type) or any bone marrow failure syndrome like aplastic anemia


  • Carbimazole, clozapine, dapsone, dipyrone, methimazole, penicillin G, procainamide, propylthiouracil, rituximab, sulfasalazine, ticlopidine, hydroxychloroquine, infliximab, lamotrigine, oxacillin, quinine, infliximab, trimethoprim-sulfamethoxazole, hydroxyurea, any systemic steroids. Any chemotherapeutic agent or biologic.

For additional frequently asked questions, please click to download the PDF.

Related Documents

Terms and Definitions

Reference IRB Materials

  Consent Form

Educational Resources

Key Publications

Additional Publications and Resources



If you have questions or require additional information regarding the ANC by Duffy Status project, please contact [email protected].