Using flow cytometry to understand disease physiology

Introduction to flow cytometry
Flow cytometry and disease physiology
Conclusion
References
Further reading


Introduction to flow cytometry

By definition, flow cytometry refers to the immunophenotyping technique in which cell suspensions are stained with specific fluorescently labeled antibodies. These cell suspensions can be derived from a wide range of sample types, including blood, bone marrow, cerebrospinal fluid (CSF), pleural fluid, microorganisms, soluble antigens, and even strong fabrics. Once injected into the flow cytometer, this technique can provide a great deal of information about the cells in the sample.

Image Credit: mh_enders/Shutterstock

For example, flow cytometry can distinguish different cellular properties from morphology at the cell cycle stage. Additionally, the information provided by a flow cytometer reflects individual cells within the population rather than providing an average which is often the result of other molecular biology techniques like Western blot.

Flow cytometry and disease physiology

The first clinical application of flow cytometry was reported in the late 1980s when it was used to manage patients with human immunodeficiency virus (HIV). Since then, flow cytometry has become an indispensable tool in various medical fields, especially in hematology, immunology and clinical pathology.

Immunological diseases

Primary immunodeficiencies (PIDs) can be classified into nine categories, which include severe and combined immunodeficiencies (SCID), combined immunodeficiencies with syndromic features, mainly antibody deficiencies, immunodysregulated disorders, abnormalities affecting phagocytes, abnormalities innate immunity, autoinflammatory conditions, complement deficiencies, and PID phenocopies. Typically, severe PID causes symptoms to develop soon after birth; however, accurate diagnosis of these disorders requires specific and sensitive tests.

As a result, flow cytometry is often considered the method of choice for diagnosing and studying PID. Typically, a flow cytometry test is used after a clinician has assessed the patient’s clinical presentation and performed some basic laboratory tests. If the healthcare professional suspects an adaptive immunity defect, then basic lymphocyte phenotyping will be performed to assess the number and proportion of immune cells, as well as to provide insight into the patient’s cellular processes, including cell proliferation , cytokine secretion, and cytotoxicity, to name a few.

Flow cytometry can also be used to assess subpopulations of different immune cells to better understand the physiology of a given patient’s disease state. For example, if a clinician wishes to assess a patient’s lymphocyte subpopulations, they may request a flow cytometry test on CD4+ and CD8+ T cells, as well as information on B cells and natural killer cells ( NK) within the patient. to taste. In addition to its usefulness in the diagnosis of primary or secondary immunodeficiency, flow cytometry used to assess lymphocyte subpopulations may also be particularly useful in monitoring patient response to certain immunotherapies, such as anti-antibody treatment. CD20 known as rituximab.

Comparatively, extended phenotypic analysis can better understand the behavior of dendritic cell subpopulations, regulatory T cells, and recent thymic emigrants.

Hematology and oncology

One of the most important applications of flow cytometry for disease physiology purposes is in hematology and oncology, especially when a hematopoietic neoplasm is suspected in blood, bone marrow, or tissue biopsy specimens. . For this purpose, a neoplastic cell is identified by flow cytometry by quantitatively measuring changes that occur in the distribution of cellular subsets of qualitative changes in antigen expression.

Image Credit: Nestor Rizhniak/Shutterstock

Image Credit: Nestor Rizhniak/Shutterstock

For example, in the case of B-cell lymphoma, flow cytometry is useful in determining B-cell clonality, which often equates to neoplasia. Neoplastic T cells that indicate T-cell lymphomas and lymphoproliferative processes can also be assessed by flow cytometry of T cell subsets and/or T cell antigen expression assessment.

Samples from patients suspected of having a platelet disorder are also often subjected to flow cytometry. For example, flow cytometry is often used to determine the presence of autoantibodies against platelets which are often indicative of immune thrombocytopenia. This approach is considered superior to other laboratory tests that detect antiplatelet antibodies, especially those that are low density or labile. Several other platelet disorders, including Glanzman’s thrombasthenia and Bernard-Soulier syndrome, can also be diagnosed and monitored by flow cytometry by evaluating the presence of antigens on the surface of these platelets.

Conclusion

Although flow cytometry is often considered primarily a diagnostic tool, it is also widely used to monitor the effectiveness of treatments and the progression of certain diseases. Together, these flow cytometry applications contribute to a better overall understanding of various health conditions to improve patient outcomes in the future.

References

Further reading

Leave a Reply