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Arteropathies, Microcirculation and Vasculitis
Published in Mary N. Sheppard, Practical Cardiovascular Pathology, 2022
The lymphatic system has three main roles: (1) fluid balance, (2) immunity and (3) fat absorption. The heart has an extensive lymphatic system (Fig. 11.15). Acute lymphangitis is usually caused by virulent bacteria, most commonly Streptococcus pyogenes, which invade and multiply in the lymphatics, causing subcutaneous red streaks draining an infected area. Lymphangitis leads to lymphadenitis and may herald septicaemia. Blockage of the lymphatics by cancer causes lymphoedema, especially in the upper limbs in breast carcinoma. Chronic filarial lymphangitis causes elephantiasis due to lymphoedema.
Sentinel lymph node mapping in cervical cancer
Published in Charles F. Levenback, Ate G.J. van der Zee, Robert L. Coleman, Clinical Lymphatic Mapping in Gynecologic Cancers, 2022
David Cibula, Martina Borcinova
Lower leg lymphedema (LLL) is the most prevalent postoperative morbidity following the treatment of gynecologic cancer. Lymphedema is a manifestation of lymphatic system insufficiency and deranged lymph transport.29 It is characterized by the swelling of one or both lower limbs caused by excess accumulation of water, plasma proteins, extravascular blood cells, and parenchymal/stromal cell products in the limb tissues.60
Management of Conditions and Symptoms
Published in Amy J. Litterini, Christopher M. Wilson, Physical Activity and Rehabilitation in Life-threatening Illness, 2021
Amy J. Litterini, Christopher M. Wilson
The lymphatic system is responsible for (1) immune defense (e.g. removal of debris from the interstitium, production of lymphocytes, and protection from the spread of malignancy); (2) nutrition (e.g. intestinal lymph vessels absorb digested fats/lipoproteins); and (3) maintenance of fluid balance (i.e. filtration/reabsorption). An estimated 10% of the capillary ultrafiltrate is considered the lymph obligatory load which returns to the circulatory system via reabsorption by the lymphatic system.62Edema is the general term for swelling due to increased fluid collection in the interstitium; it is a visible and palpable sign of injury or a malfunctioning system, and is associated with different etiologies. In the body’s initial response to injury, acute edema results from a transfer of fluid (exudate) from the blood into tissue. Edema, which can be either generalized/diffuse or localized, can also result from immobilization, or it can be an initial symptom of an underlying disease such as CHF or other venous system disorders (see Chapter 8).62Lymphedema, considered a chronic condition, is the abnormal collection of protein-rich lymph fluid in the interstitium that, if left untreated, can cause chronic inflammation, fibrosis of the affected tissues, and/or wounds.
The tumor microenvironment and triple-negative breast cancer aggressiveness: shedding light on mechanisms and targeting
Published in Expert Opinion on Therapeutic Targets, 2022
Natsuki Furukawa, Vered Stearns, Cesar A. Santa-Maria, Aleksander S. Popel
The physiological roles of the lymphatic system are to collect interstitial fluid from tissues, absorb lipids from the digestive system, and immune surveillance. In the TME, cancer cells release growth factors and cytokines such as VEGF-C to induce lymphangiogenesis. As a result, TNBC cells may invade these lymphatic vessels, migrate to the lymph node, and eventually exit the lymphatic system to enter the venous system. Disseminated TNBC cells may reach and metastasize to organs such as lung, bone, liver, and brain via the circulatory system [144]. During the invasion process, cancer cells remodel the lymphatic endothelial cells to facilitate invasion. Lee et al. demonstrated that TNBC cells induced expression of CCL5 from lymphatic endothelial cells. CCL5 recruited CCR5-positive TNBC cells to lymphatic vessels and facilitated invasion of the lymph nodes [145]. Other chemokine signaling pathways known to recruit TNBC cells to the lymphatic vessel are CCL21/CCR7, CXCL12/CXCR4, and CCL27/CCR10 [146].
Clinical and immunologic differences in cellulitis vs. pseudocellulitis
Published in Expert Review of Clinical Immunology, 2021
Michael Goldenberg, Henry Wang, Trent Walker, Benjamin H Kaffenberger
Lymphedema is a high-protein edema that results from lymphatic insufficiency [42]. Lymphedema can be related to cancer, filariasis [8], anatomic abnormalities and obesity, or genetic disorders [43]. When functioning properly, the lymphatic system channels extracellular fluid and large molecules to lymph nodes where immune surveillance can occur before draining fluid to the vascular system. When this transport is impeded, the excess proteins remain in the subcutaneous tissue [42], osmotically drawing fluids into the area, creating dermal edema [44] and increasing risk for infection [42]. The impaired lymphatic return also contributes to microtears in connective tissue, triggering an influx of neutrophils [44]. Decreased tissue perfusion results in tissue hypoxia, resulting in upregulation of hypoxia-inducible factor 1 alpha (HIF-1a) and downregulation of hypoxia-inducible factor 2 alpha (HIF-2a) in lymphatic endothelial cells [45]. One study showed that HIF-2a is an important mediator for proper lymphatic function and suggests that restoring HIF-2a via adenovirus mediated gene therapy could reduce chronic morbidity related to lymphedema [45]. The poor tissue perfusion also contributes to build up of toxins within subcutaneous tissues, leading to an inflammatory infiltrate with systemic leukocytosis (figure 3) [44].
Components of specific immunity in host defense
Published in International Reviews of Immunology, 2021
Invading microbial pathogens are immediately trapped in the nearest specialized organ, known as lymph nodes, where necessary immune responses will develop to clear the microbes. The pathogen is transported to the lymph nodes through a network of channels and, collectively, called as lymphatic system. In these organs, microbial pathogens are ingested by the phagocytic or similar types of cells known as antigen presenting cells (APCs) and its component is processed and presented by these cells to the T cells to develop appropriate immune responses. Another cell type known as B cells produce wide range of molecules that bind to the surfaces of the microbes known as antibody and subsequently inactivate the pathogen. Based on the pathogen, T cells can differentiate into various functional subtypes to provide necessary pathogen-specific immune responses. In addition to microbial pathogens, these cells play an important role in immune homeostasis. The dysregulated B and T cells can also result to the immune catastrophe that may result to the development of cancer or autoimmune diseases. This issue of International Reviews of Immunology discusses some aspects of the tertiary lymphoid structure, APCs, B and T cells in normal immune function and in immunopathogenesis (Figure 1).