Overview of Chronic Leukocytosis and Genetic Alterations

Jenifer Catherine^*
*Correspondence: Jenifer Catherine, Department of Molecular Cell Biology, University of Brasilia, Federal District, Brazil, Email:

Introduction

In order to rule out potential reasons of the presenting lab abnormalities, doctors should be able to conduct physical exams and focused histories. This is because the broad differential diagnoses of leukocytosis necessitate study beyond simple laboratory workup. Careful histories, physical examinations, medication reconciliations, family histories, and the potential requirement for consultants for procedures (e.g., genetic testing, hematology/oncology consultations, infectious disease, etc.) must be finished in order to evaluate for these causes. Stem cells in the bone marrow differentiate into megakaryoblasts, which become megakaryocytes that produce platelets, erythroblasts, which produce red blood cells, myeloblasts, which produce eosinophils, basophils, and neutrophils, as well as monocytes and lymphoid progenitor cells (that will become B or T lymphocytes).

Description

Any cells from the myeloblast, monoblast, and lymphoid lineages are referred to as leukocytes. Based on the increased cell line, leukocytosis can be categorised. Neutrophilia, eosinophilia, basophilia, monocytosis, and lymphocytosis are all terms used to describe a complete blood count (CBC) that has predominantly high neutrophils as well as eosinophils, basophils, monocytes, and lymphocytes. A thorough history and physical examination are essential to support specific differential diagnoses of the particular leukocytosis presenting itself. The kind of cell raised may help to determine the trigger for leukocytosis. The general causes of some of the most typical leukocytosis presentations will be discussed in this article. A peripheral blood smear is obtained during a regular blood draw and used to determine the leukocyte count.

Depending on age and race, different cell count ranges exist. Leukocyte numbers are often much higher in babies than in adults. Lymphocytes dominate the peripheral smear during adolescence. By adulthood, neutrophils become the predominate cell line in the peripheral blood smear. For general reference ranges, see Table 1. WBC count and differential are also influenced by black African, Middle Eastern, and West Indian ancestry. In comparison to individuals of Hispanic and European heritage, patients from these backgrounds may have lower absolute neutrophil counts and lower WBC counts. This is known as benign ethnic neutropenia (BEN), and it can be recognised in a patient of African heritage with no signs of infection during the history-taking and physical examination, as well as chronically low neutrophil counts on the complete blood count (CBC). When assessing a patient of African origin with BEN, it is crucial to take this into account because their leukocytosis may show within the normal laboratory reference range for CBCs but be higher in contrast to their prior CBCs. In reaction to an inflammatory stressor/cytokine cascade, or as a component of an autonomous myeloproliferative neoplasm, leukocytosis can occur abruptly, frequently transiently, or persistently. The most typical manifestation is neutrophilia, but doctors should be aware of the other cell lines that may be implicated in acute and chronic presentations. The underlying cause of leukocytosis can be determined and the proper course of treatment can be guided by a thorough history, physical examination, medication reconciliation, full review of a CBC with differential, and comparison to earlier CBCs, according to experts.

On a CBC, leukocytosis is a very frequent phenomenon with a number of causes. Obtaining a CBC with differential, which assesses the various cell lines, is the first step. In patients with unexplained leukocytosis, a peripheral blood smear is reasonable and can be beneficial. Obtaining a manual differential can be especially useful when analysing aberrant cells or when there is doubt about the accuracy of an automated leukocyte differential. Blood should be drawn from a recent, anticoagulated lab draw or immediately from a finger stick puncture while examining the peripheral smear under a microscope. Blood on the slide is graded from thick to thin during slide preparation. The smear is air dried before being stained with a dye like Wright or May-Grunwald-Giemsa, which results in cells with pink cytoplasm and blue nuclei. The physician will next start reviewing the slides under the microscope on the feathery or thin edge of the smear, where the cells are barely overlapping, and work their way into the thicker portion of the smear, where the WBCs usually reside. Leukocytes must be examined at high magnification using an oil-immersion lens to look for anomalies and inclusions. Significantly aberrant observations include lymphoma cells as well as immature granulocytes and their progenitors, including blasts and myelocytes [1-5].

Conclusion

Treatment for leukocytosis depends on the underlying cause. For instance, a neutrophilia may be caused by an underlying infection, in which case the doctor will need to conduct a thorough history and physical examination, order any necessary blood tests, and use imaging to find the source of the infection and treat it. To look at drug-induced leukocytosis, medication reconciliation, such as any recent steroid use, should also be finished. It is also possible to determine recent physical stress that resulted in a leukocytosis from history. If identified, neither of these cases needs additional treatment. More serious reasons, such leukemias and lymphomas, should immediately demand the engagement of haematology and oncology specialty services for the precise imaging and laboratory testing required to help guide treatment.

References

1. Briggs, C., P. Harrison, D. Grant, J. Staves, and S. J. MacHin. "New quantitative parameters on a recently introduced automated blood cell counter–the XE 2100TM." Clin Lab Haematol 22 (2000): 345-350.

Google Scholar, Crossref, Indexed at

2. Barnes, P. W., S. L. McFadden, S. J. Machin, and E. Simson, et al. "The international consensus group for hematology review: suggested criteria for action following automated CBC and WBC differential analysis."  Lab Haematol  11 (2005): 83-90.

Google Scholar, Crossref, Indexed at

3. Benattar, L., and G. Flandrin. "Comparison of the classical manual pushed wedge films, with an improved automated method for making blood smears." Hematol Transfus Cell Ther 41 (1999): 211-215.

Google Scholar, Crossref, Indexed at

4. Tefferi, Ayalew, Curtis A. Hanson, and David J. Inwards. "How to interpret and pursue an abnormal complete blood cell count in adults."  Elsevier, (2005): 923-936.

Google Scholar, Crossref, Indexed at

5. Mossafa, H., S. Tapia, G. Flandrin and X. Troussard, et al. "Chromosomal instability and ATR amplification gene in patients with persistent and polyclonal B-cell lymphocytosis (PPBL)." Leuk Lymphoma 45 (2004): 1401-1406.

Google Scholar, Crossref, Indexed at