Lymphocytes (Lymphocytosis, Lymphopenia) Basic Information Definition Lymphocytes consist of T cells, B cells, and natural killer cells. These cells are an integral part of the humoral and cell-mediated immune response. Morphologically, these cells are small and round with a scant rim of basophilic cytoplasm with a round nucleus and a condensed chromatin pattern. Occasionally, these cells contain few eosinophilic cytoplasmic granules. Typical Normal Range (US units; SI units) 1.2 to 5.0 × 103/µL Physiology Lymphocytes have specific roles in the immune response as either effector cells or regulator cells. These cells can be further identified as T or B cells based on the presence of cellular antigens such as CD3 (T cell), CD79 or CD20 (B cells), CD4 (helper T cells), or CD8 (cytotoxic T cells). B cells are antibody producing cells and are important in the humoral immune response. T cells are the most predominant lymphocytes and have prominent roles as both effector and regulatory lymphocytes. Lymphoid cells can be identified in many different tissues in the body including lymph nodes, spleen, bone marrow, thymus, gastrointestinal (GI) tract, and respiratory tract. These cells have the ability to enter and exit lymphoid tissue and peripheral blood. Many of the other leukocytes such as neutrophils are unable to reenter the peripheral blood once they enter the tissue. Causes of Abnormally High Levels Increases in lymphocytes or lymphocytosis can be transient secondary to epinephrine release with excitement or fear, or as part of an antigenic response. Presence of reactive lymphocytes are often seen in patients with chronic antigenic stimulation. Recently vaccinated animals will often have low numbers of circulating reactive lymphocytes. Patients with leukemia or lymphoma may have large or atypical lymphocytes in circulation or may have unusually high levels of lymphocytes (>30,000/µL).< div class='tao-gold-member'> Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Aggressive Stallion Behavior Aflatoxin Toxicosis Biliary Atresia Black Widow Spider Toxicosis Stay updated, free articles. Join our Telegram channel Join Tags: Clinical Veterinary Advisor The Horse Jul 24, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Lymphocytes (Lymphocytosis, Lymphopenia) Full access? Get Clinical Tree
Lymphocytes (Lymphocytosis, Lymphopenia) Basic Information Definition Lymphocytes consist of T cells, B cells, and natural killer cells. These cells are an integral part of the humoral and cell-mediated immune response. Morphologically, these cells are small and round with a scant rim of basophilic cytoplasm with a round nucleus and a condensed chromatin pattern. Occasionally, these cells contain few eosinophilic cytoplasmic granules. Typical Normal Range (US units; SI units) 1.2 to 5.0 × 103/µL Physiology Lymphocytes have specific roles in the immune response as either effector cells or regulator cells. These cells can be further identified as T or B cells based on the presence of cellular antigens such as CD3 (T cell), CD79 or CD20 (B cells), CD4 (helper T cells), or CD8 (cytotoxic T cells). B cells are antibody producing cells and are important in the humoral immune response. T cells are the most predominant lymphocytes and have prominent roles as both effector and regulatory lymphocytes. Lymphoid cells can be identified in many different tissues in the body including lymph nodes, spleen, bone marrow, thymus, gastrointestinal (GI) tract, and respiratory tract. These cells have the ability to enter and exit lymphoid tissue and peripheral blood. Many of the other leukocytes such as neutrophils are unable to reenter the peripheral blood once they enter the tissue. Causes of Abnormally High Levels Increases in lymphocytes or lymphocytosis can be transient secondary to epinephrine release with excitement or fear, or as part of an antigenic response. Presence of reactive lymphocytes are often seen in patients with chronic antigenic stimulation. Recently vaccinated animals will often have low numbers of circulating reactive lymphocytes. Patients with leukemia or lymphoma may have large or atypical lymphocytes in circulation or may have unusually high levels of lymphocytes (>30,000/µL).< div class='tao-gold-member'> Only gold members can continue reading. Log In or Register to continue Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related Related posts: Aggressive Stallion Behavior Aflatoxin Toxicosis Biliary Atresia Black Widow Spider Toxicosis Stay updated, free articles. Join our Telegram channel Join Tags: Clinical Veterinary Advisor The Horse Jul 24, 2016 | Posted by admin in SMALL ANIMAL | Comments Off on Lymphocytes (Lymphocytosis, Lymphopenia) Full access? Get Clinical Tree
