Dear Editor,
We thank Dr. Al-Mendalawi1 for his comments on our study of gestation-wise reference ranges of neutrophil counts in Indian newborns.2 The main objective of our study was to generate normative data for neutrophil counts in Indian neonates, taking cognizance of the fact that such data are lacking in the Indian context. As noted by the author, our study had its share of limitations, including being a single-center hospital-based study with a limited sample size and lack of serial neutrophil count from day one to seven. Our esteemed reader has rightfully observed that India is a multiethnic country, and therefore, we should have looked at possible ethnic variations in newborn neutrophil counts. There can indeed be ethnic variations in blood cell counts – a condition called benign ethnic neutropenia is reported in the literature that is characterized by low absolute neutrophil count.3 This may affect as much as 25% to 50% of persons of African descent and some ethnic groups in the Middle East.4 At the same time, we should remember that reference ranges for neutrophil counts and other blood cell counts in adults and children do not routinely refer to the ancestry of the population since this does not carry serious clinical implications. There is no reason why the situation would be different for newborns. We must concede that our study population was mostly homogeneous in the sense that the vast majority were of eastern Indian descent, and we did not plan to study ethnic variation when we conceived the study.
references
- 1. Al-Mendalawi M. Gestation-wise reference ranges of neutrophil counts in Indian newborns. Oman Med J 2020;35(2):e118.
- 2. Das A, Ray S, Chattopadhyay A, Hazra A, Mondal R. Gestation-wise reference ranges of neutrophil counts in Indian newborns. Oman Med J 2019 Mar;34(2):131-136.
- 3. von Vietinghoff S, Ley K. Homeostatic regulation of blood neutrophil counts. J Immunol 2008 Oct;181(8):5183-5188.
- 4. Haddy TB, Rana SR, Castro O. Benign ethnic neutropenia: what is a normal absolute neutrophil count? J Lab Clin Med 1999 Jan;133(1):15-22.