To the Editor: We read with much interest the article by Bhatia et al., published online first in Indian Journal of Pediatrics [1] but at the same time would like to make the following comments, clarification to which would benefit the general readers of IJP.

The authors mention that P. falciparum infection was diagnosed at the outset along with a complete blood count and peripheral smear suggestive of leukemoid reaction and no blasts. Further, the child also improved with artimisin derivatives over next 48 h with decrease in total leucocyte count, reassuring that the leukemoid reaction was due to malarial infection [2]. In this scenario, the utility of performing a bone marrow examination in the index patient is not clear.

The patient had severe anemia, attributed to hemolysis and hypersplenism secondary to P. falciparum infection. It is expected to find plenty of nucleated red blood cells (nRBCs) in the peripheral blood of the patient. Automated hematology analyzers may falsely count these nRBCs as leucocytes, giving spuriously high leucocyte count [3]. Most new generation analyzers give flags (WBC* R, NRBC, Review Slide, Blasts etc.) to identify abnormal cells and in such cases the samples should be reviewed manually [4]. We had previously reported an infant with β-thalassemia presenting with hepatosplenomegaly and falsely very high leucocytosis on automated coulter, being suspected of infantile leukemia with hyperleucocytosis [5]. Though the authors have not given the nRBC count, in such scenarios, it is advised to calculate the corrected WBC count using the following formula: corrected WBC count (/mm3) = TLC X 100 ÷ {nRBC per 100 WBC + 100}. On the other hand, acute hemolysis itself is also implicated as one of the causes for leukemoid reaction [2].

Anirban Mandal 1 and Puneet Kaur Sahi 2

Department of Pediatrics, 1 Sitaram Bhartia Institute of Science and Research and 2 Kalawati Saran Children’s Hospital, New Delhi, India. E-mail: anirban.nrs@gmail.com

References

1. Bhatia R, Agarwal P, Rajwaniya D. Leukemoid reaction due to P. falciparum infection. Indian J Pediatr. 2016. doi:10.1007/s12098-016-2192-1.

2. George TI. Malignant or benign leukocytosis. Hematology Am Soc Hematol Educ Program. 2012;2012:475–84.

3. Cornbleet J. Spurious results from automated hematology cell analyzers. Lab Med. 1983;14:509–14.

4. Barnes PW, McFadden SL, Machin SJ, Simson E; International Consensus Group for Hematology. The International Consensus Group for Hematology review: suggested criteria for action following automated CBC and WBC differential analysis. Lab Hematol. 2005;11:83–90.

5. Singh A, Mandal A, Rishi B, Sahi P. Spurious hyperleukocytosis. Int J Pediatr. 2015;3:799–800.

Author’s Reply

To the Editor: We are grateful to Mandal et al. for reading our manuscript with interest [1]. I agree that the initial peripheral blood film (PBF) examination did not have any blast cells but premature granulocytes in the form of myelocytes, metamyelocytes, promyelocytes were seen. We did a bone marrow examination to rule out leukemia. I agree with the observation that nucleated RBC’s could give rise to a spuriously high WBC count; we have reported the corrected leukocyte count on the basis of the peripheral smear examination seen by a pathologist. Total leukocyte count was based on the peripheral smear examination and not on the basis of automated cell analyser.

Ravi Bhatia

Department of Pediatrics, Pacific Medical College and Hospital, Udaipur, Rajasthan, India. E-mail: bhatiaravi.ped@gmail.com

Reference

1. Bhatia R, Agarwal P, Rajwaniya D. Leukemoid reaction due to P. falciparum infection. Indian J Pediatr. 2016. doi:10.1007/s12098-016-2192-1.