Haema 2021; 12(1): 3-4
Consultant Haematologist, University Hospital of Alexandroupolis
Full PDF |
A relative and absolute neutropenia has been described in black Africans, African Americans, Arabs (Saudi Arabians, Palestinians), and Jewish Yemenites (ethnic or racial neutropenia).1-3
The total body neutrophils have been found to be the same in adults from West Indies living in the UK as in the white Britons, but individuals from West Indies have a greater number of neutrophils in the bone marrow storage pool, while Europeans have more in circulation; provocation of a neutrophil response, either experimentally by exercise or by natural infection, leads to rises to the same level in both races. There is probably a genetic factor underlying ethnic neutropenia, but environmental factors may also play a role since the neutrophil count rises with higher socioeconomic status in Africans, and declines in Europeans living in West Africa.1,3,4
Note: peripheral blood and bone marrow films of people with ethnic neutropenia are normal.
- Consider secondary causes of neutropenia e.g. HIV, splenomegaly, drugs, hairy cell leukaemia, and acute leukaemia (particularly acute promyelocytic leukaemia) before a diagnosis of racial neutropenia is made.
- Chronic fevers with neutropenia can arise from malaria, disseminated tuberculosis (often with a negative tuberculin skin test), visceral leishmaniasis, brucellosis, and HIV infection.5,6
Table 1 shows the normal leukocyte counts in 123 non-elite healthy blood donors from Nigeria in comparison with Europeans (From: Cook GC, Zumla AL. Manson’s Tropical Diseases, 22nd Ed., 2008).
Remember: the neutrophil count does not drop below 1.0×109/l in black Africans.
- Cook GC, Zumla AI. Manson’s tropical disease. 22nd ed. London: Εlsevier Saunders; c2008.
- Lewis SM, Bain B, Bates I. Dacie, Lewis’s Practical Haematology, 9th ed. Edinburgh: Churchill Livingstone; c2001.
- Gilles HM. Normal haematological values in tropical areas. Clin Haematol. 1981 Oct;10(3):697-706.
- Fleming AF, Akintunde EA, Harrison KA, Dunn D. Leucocyte counts during pregnancy and the puerperium and at birth in Nigerians. E Afr Med J. 1985 Mar; 62(3):175-84.
- Spira AM. Assessment of travellers who return home ill. Lancet. 2003 Apr;361(9367):1459-69.
- Ryan ET, Wilson ME, Kain KC. Illness after international travel. N Engl J Med. 2002 Aug;347(7):505-16.