Probable causes of infant lymphocytosis

Probable causes of infant lymphocytosis

1. Author: Negash Alamin

Occupation: Labtechnologist (BSC)
Title: Probable causes of infant lymphocytosis and inverted
lymphocyte count
Date: Mar 9, 2019
E-mail: [email protected]
Facebook: Negash Andreas Realis

2. Introduction
Children specifically infants have not just high lymphocyte count but high total CBC count.
Every parameter is higher than adults. In this paper I will give the three main probable reasons
that I think is the cause of infant lymphocytosis. It may be due to their rapid development
(metabolic) proliferation due to hormones like erythropoietin which boost RBC or due to
infections or due to their exposure to passive and artificial immunization after birth.

Main Discussion
We must not assume conclusively at first that lymphocytosis is a result of pathological
conditions; we say that lymphocytosis is present in adults when it goes greater than
4000/microliter, greater than7000 in older children, and greater than 9000 per microliter in
infants
1
. There is a need for effective differential diagnosis regarding the distinction between
metabolic lymphocytosis and pathological lymphocytosis; similar to leukaemoid reaction and
leukemia. First we will exhaust all investigations to detect anomalies like viral pathogens,
bacterial pathogens and other vermins; then, if positive we will go on to conclude that the infants
lymphocytosis is most probably caused by pathological conditions; but, if the lymphocytosis
decreases through time and eventually goes away; we conclude that it is most probably due the
rapid developmental rate of infant’s hematopoiesis due hormonal proliferation. In the table
below we see that infants do have a higher rate of all parameters; in their first month of life.

Test RBC Age
0-1 month
Range
3.90-5.90
million/µ
Test Hematocrit Age
0-1 month
Range
42-65%
Test Hemoglobin Age
0-1 month
13.4-19.9 g/dl
Test White cell
count
Age 0-1 9,000-
30,000/µl
Table 1 Different blood parameters of neonates
2


1
Wikipedia
2
www.healthcare.uiowa.edu/path_handbook/appendix/heme/pediatric_normals.html

3. Figure 1 DF parameter

The normal levels of lymphocytes in adult DF count constitute 20 to 40% of circulating white
blood cells. Now, in infants according to my sources there could only be three reasons that child
lymphocyte count would be excessive i.e. more than 9000 per microliter:
1- Rapid developmental rate of infants (hormonal)
2- Infections (pathological)
3- Exposure to vaccines (passive and artificial immunization)

4. 1-Hormonal issues
As the child is mostly made of still proliferating and maturing cells that makeup its organs there
will be a high participation of the endocrine system in facilitating cellular maturation; thus, the
role of hormones cannot be neglected.

2-Lymphocytosis could be a result of infection in children
 EBV
3

 Hepatitis
 CMV
 Tuberculosis
 Pertussis
4

Infections stimulate the naïve immune system of the baby to proliferate and fight pathogens that
enter its body.
3-Exposure to vaccines
As it is obviously known children get vaccines after birth:
 BCG vaccine for Tuberculosis
 Quadrivalent polio vaccine i.e. OPV0, OPV 1, OPV 2, OPV 3
 Dpt-hep-Hib
 MMR etc.
In addition to passive antibodies from the mother via breast milk; vaccines also boost infant’s
immune system and facilitate rapid proliferation of B-cells and T-cells.








3
Infectious mononucleosis
4
A main culprit in the pathological rise of lymphocytes
Neonate From birth to one month
Infant One month to 2 years
Children 2- 12 years
Adolescent 12-16 years
Adult Above 18years

5. Conclusion: As we have seen hitherto there are several reasons why CBC parameters increase in
infants especially lymphocytes; as can be observed from fig.1 the rate of lymphocytosis increases
rapidly starting from one month to one year and the reason that I surmise is due to the three
reason that I have already mentioned above.

References:
www.medscape.com
www.wikipedia.com
www.mayoclinic.com
Textbook of Medical laboratory Technology; Ramnik Sood MD: 2006