Lymphocytes

Lymphocytes are a crucial component to the body's immune. As pregnancy progresses, Dynamic shifts and lymphocyte production and function occur to accommodate the growing fetus while ensuring maternal Health. Understanding the intricate interplay between lymphocytes and pregnancy is essential for unraveling the complexities of Maternal Fetal immunology and providing​ comprehensive care for improving pregnancy outcomes.

Lymphocyte Testing

The absolute lymphocyte count tells you the total count of lymphocytes in the sample. The lymphocyte percentage tells you what percentage of white blood cell count is made up of lymphocytes. It is found in the complete blood count (CBC) with differential panel.

The percentage is arguably more accurate that absolute, as it takes into account the total production of white blood cells and compares the amount of lymphocytes to this total. 

Lymph is Latin for “water.” Lymphocytes are a type of non-granulated white blood cell. They originate from lymphoblasts in the spleen, lymph nodes, tonsils, thymus, intestines, bone marrow and appendix. The primary job of lymphocytes is to produce antibodies in response to bacteria, viruses, or any other potentially pathogenic antigen, including cancer.
Lymphocytes include B cells, T cells, and natural killer (NK) cells. All crucial components of the immune system, each with unique formation processes and functions.

• T cells, or T lymphocytes, also originate from the bone marrow. However, they migrate to the thymus gland, where they undergo maturation and selection processes. T cell development is regulated by various thymic hormones and cytokines. T cells play a central role in cell-mediated adaptive immunity or acquired immunity. They include cytotoxic T cells (CD8+), which can directly kill infected or abnormal host cells, and helper T cells (CD4+), which coordinate immune responses. Regulatory T cells (Tregs) control and modulate immune responses, while memory T cells "remember" previous encounters with pathogens. T cells recognize antigens and activate the B cells. They can also kill viruses and cancer cells.
• B cells are formed in the bone marrow. In the bone marrow, they undergo a process called B lymphopoiesis. During this process, genes are rearranged to generate a diverse range of B-cell receptors (antibodies). B cell development is influenced by various cytokines and growth factors. These factors support B cell proliferation and differentiation. B cells are primarily responsible for humoral immunity, a component of the adaptive immune system. Once activated by an antigen, they differentiate into plasma cells, which produce antibodies. Antibodies can neutralize pathogens and tag them for destruction by other immune cells. Plasma cells are differentiated from antigen-activated B cells in secondary lymphoid organs such as the spleen and lymph nodes.
• Plasma Cells compose 2% to 3% of all lymphocytes. Plasma cells engulf antigens, present them to T-cells and produce large amounts of antibodies in response to antigens. Antibodies can neutralize pathogens by blocking their ability to infect host cells. This can prevent the spread of infection. Antibodies tag pathogens for destruction by other immune cells, such as phagocytes. This process enhances the recognition and elimination of the pathogen. Some antibodies can trigger the complement system, a group of proteins that enhance the immune response by causing cell lysis (bursting) of the pathogen. Some B cells also differentiate into memory B cells, which "remember" the antigen. This provides a quicker and more robust immune response upon re-encounter with the same antigen in the future. Long lived plasma cells (LLPC) live for longer and secrete antibodies. They do not need continued antigen exposure to produce antibodies.
• Natural Killer (NK) cells play a role in our innate immune responses. NK cells form in the bone marrow. NK cells attack any foreign cell, including cancer cells. The development of NK cells is regulated by various cytokines. They can recognize cells that lack self-antigens and induce apoptosis in these cells. NK cells provide rapid immune responses in the absence of prior exposure to the pathogen.

Lymphocytes in Pregnancy

In pregnancy there is a decrease in lymphocyte production of 36%. Lymphocytes are usually between 12 - 20% of total white blood cell counts.

This helps to protect the placenta and fetus from immune system attacks, as they are foreign cells. These levels are decreased through the second trimester and increase again during the third trimester in preparation for childbirth.[1]

​To prevent the rejection of the developing fetus, the maternal immune system becomes more tolerant. Tregs suppress immune responses against fetal antigens. Pregnancy induces a shift in the immune response, favoring a type 2 helper T cell (Th2) response. This shift is thought to support the maintenance of pregnancy. Th2 responses are associated with antibody production and tissue repair.

High Lymphocytes in Pregnancy

​Elevated lymphocytes are associated with an increased risk of miscarriage and implantation failure. This may be seen in those with repeated failed IVF transfers.

B cells have been implicated in preeclampsia due to the production of autoantibodies against adrenal receptors. These autoantibodies are seen in 70 - 95% of women with preeclampsia.

A few Studies have reported that total white blood cell counts, neutrophil counts, and lymphocyte counts are significantly higher in patients with gestational diabetes mellitus when compared to healthy controls.

Most Common Causes of High Lymphocytes in Pregnancy

• Dehydration
• Acute Infections
• Latent Viral Infections (Epstein-Barr, Cytomegalovirus, HPV)
• Autoimmune Hypothyroidism
• Chronic Inflammatory Disease
• Asthma
• Hyperthyroidism
• Placental Dysfunction
• Nutritional Deficiencies (Vitamin D)
• Adrenal Hypofunction
• Chronic Stress
• Certain Medications
• Myelodysplastic Syndromes

Low Lymphocytes in Pregnancy

Lymphocytopenia is a normal presentation in pregnancy. Levels that are excessively low, or below normal ranges can increase the risk of infections in pregnancy.

Lymphocytes are inversely related to serum cortisol levels.

In preeclampsia there is a reduced shift from TH-1 to TH-2 T helper cells​.

Some studies have found a connection between insulin resistance, gestational diabetes mellitus, and low lymphocyte production. Increased serum levels of very low density lipoproteins inhibits lymphocyte proliferation by disturbing DNA synthesis. This could explain the severe reduction in lymphocyte counts often seen in women with gestational diabetes with more severe blood sugar elevations.

Most Common Causes of Low Lymphocytes in Pregnancy

• Chronic Viral Infections (Latent Viruses)
• Autoimmune Disease
• Immunodeficiency Disorders
• Iron Overload/Hemochromatosis
• Nutritional Deficiencies (Zinc, Selenium, Magnesium)
• Adrenal Hyperfunction
• Chronic Mycotoxin Exposure
• Toxin Exposure
• Low Progesterone
• Certain Medications

Want to Know More...

Check Out My Advanced Lab Analysis in Pregnancy Practitioner Course
​MEAC Continue Education Credits Available

Click Here to See Course Details

---

Copyright © 2024 Functional Maternity, all rights reserved.

Medical Disclaimer:
This content is for educational purposes only and is intended for licensed medical professionals. It is based on current research, subject to change, and not intended to diagnose, treat, or prevent any medical condition. This information does not replace consultation with a qualified healthcare provider. Seek professional medical evaluation and treatment from a licensed provider. Use of this information is at your own risk.​

---