medicine Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pract ...

, Aschoff bodies are nodules found in the

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...

s of individuals with

rheumatic fever Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful jo ...

. They result from

inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...

in the

heart muscle Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle tha ...

and are characteristic of rheumatic heart disease. These nodules were discovered independently by

Ludwig Aschoff Karl Albert Ludwig Aschoff (10 January 1866 – 24 June 1942) was a German physician and pathologist. He is considered to be one of the most influential pathologists of the early 20th century and is regarded as the most important German patholog ...

and Paul Rudolf Geipel, and for this reason they are occasionally called Aschoff-Geipel bodies.

Appearance

Microscopically, Aschoff bodies are areas of

of the

connective tissue Connective tissue is one of the four primary types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesenchyme derived from the mesoderm the middle embryonic germ layer. Connective tiss ...

of the

, or focal interstitial inflammation. Fully developed Aschoff bodies are

granuloma A granuloma is an aggregation of macrophages that forms in response to chronic inflammation. This occurs when the immune system attempts to isolate foreign substances that it is otherwise unable to eliminate. Such substances include infectious ...

tous structures consisting of

fibrin Fibrin (also called Factor Ia) is a fibrous, non-globular protein involved in the clotting of blood. It is formed by the action of the protease thrombin on fibrinogen, which causes it to polymerize. The polymerized fibrin, together with platele ...

oid change, lymphocytic infiltration, occasional

plasma cell Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B lymphocytes and secrete large quantities of proteins called antibodies in response to being presented specific substan ...

s, and characteristically abnormal

macrophage Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cel ...

s surrounding

necrotic Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

centres. Some of these macrophages may fuse to form multinucleated

giant cell A giant cell (also known as multinucleated giant cell, or multinucleate giant cell) is a mass formed by the union of several distinct cells (usually histiocytes), often forming a granuloma. Although there is typically a focus on the pathological ...

s. Others may become

Anitschkow cell In pathology, Anitschkow (or Anichkov) cells are often cells associated with rheumatic heart disease. Anitschkow cells are enlarged macrophages found within granulomas (called Aschoff bodies) associated with the disease. The cells are also calle ...

s or "caterpillar cells," so named because of the appearance of their

chromatin Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in r ...

. They are pathognomic foci of fibrinoid necrosis found in many sites, most often the myocardium. Initially they are surrounded by lymphocytes, macrophages, and a few plasma cells, but they are slowly replaced by a fibrous scar. Aschoff bodies are found in all the three layers of the heart, least chance in the pericardium.

Presence in cardiac lesions

The

cardiac The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...

manifestations of

are in the form of focal inflammatory involvement of the

interstitial An interstitial space or interstice is a space between structures or objects. In particular, interstitial may refer to: Biology * Interstitial cell tumor * Interstitial cell, any cell that lies between other cells * Interstitial collagenase, ...

tissue in all 3 layers of the heart, a pathological change named pancarditis. The

pathognomonic Pathognomonic (rare synonym ''pathognomic'') is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any doub ...

feature of

pancarditis Carditis (pl. carditides) is the inflammation of the heart. It is usually studied and treated by specifying it as: * Pericarditis is the inflammation of the pericardium * Myocarditis is the inflammation of the heart muscle * Endocarditis is the i ...

in the case of rheumatic heart disease is the presence of Aschoff nodules or Aschoff bodies.

Detailed description

The Aschoff nodules are foci of T lymphocytes, occasional plasma cells, and activated macrophages (Anitschkow cells) pathognomonic of rheumatic fever. These macrophages have abundant cytoplasm and central round nuclei in which chromatin condenses into a central, slender, wavy ribbon, the reason why they are sometimes called "caterpillar cells". They are especially found in the vicinity of small blood vessels in the myocardium and endocardium and occasionally in the pericardium, and also the

adventitia The adventitia () is the outer layer of fibrous connective tissue surrounding an organ. The outer layer of connective tissue that surrounds an artery, or vein – the tunica externa, is also called the ''tunica adventitia''. To some degree, its ...

of the proximal part of the aorta.

Lesions A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classifi ...

similar to the Aschoff nodules may also be found in extra-cardiac tissues.

Evolution of Nodules

Evolution of Aschoff nodules typically involve 3 stages of development all of which may be present in the heart at the same time of inspection. Stage 1. Early

exudative An exudate is a fluid emitted by an organism through pores or a wound, a process known as exuding or exudation. ''Exudate'' is derived from ''exude'' 'to ooze' from Latin ''exsūdāre'' 'to (ooze out) sweat' (''ex-'' 'out' and ''sūdāre'' 'to ...

/ degenerative stage the earliest sign of injury to the heart in rheumatic fever is apparent by fourth week of illness. Initially there is

edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's Tissue (biology), tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels t ...

of the

and increase in acid

mucopolysaccharide Glycosaminoglycans (GAGs) or mucopolysaccharides are long, linear polysaccharides consisting of repeating disaccharide units (i.e. two-sugar units). The repeating two-sugar unit consists of a uronic sugar and an amino sugar, except in the case o ...

in the ground substance. This results in a separation of the

collagen Collagen () is the main structural protein in the extracellular matrix found in the body's various connective tissues. As the main component of connective tissue, it is the most abundant protein in mammals, making up from 25% to 35% of the whole ...

fibre by accumulating

ground substance Ground substance is an amorphous gel-like substance in the extracellular space that contains all components of the extracellular matrix (ECM) except for fibrous materials such as collagen and elastin. Ground substance is active in the development, m ...

eventually the collagen fibres are fragmented and disintegrated and the affected focus takes the appearance and staining characteristics of

. Stage 2. Intermediate proliferative /

granulomatous A granuloma is an aggregation of macrophages that forms in response to chronic inflammation. This occurs when the immune system attempts to isolate foreign substances that it is otherwise unable to eliminate. Such substances include infectious ...

stage. It is at this stage of Aschoff bodies, which is

of rheumatic fever. This stage is apparent in 4 to 13 weeks of illness. The early stage of fibrinoid change is replaced by infiltration of lymphocyte T cells, plasma cells, neutrophils and the characteristic cardiac

histiocytes A histiocyte is a vertebrate cell that is part of the mononuclear phagocyte system (also known as the reticuloendothelial system or lymphoreticular system). The mononuclear phagocytic system is part of the organism's immune system. The histiocyt ...

/ Anitschkow cells at the margin of the lesion. Cardiac Histiocytes / Anitschkow are present in small numbers in the heart but their numbers are increased in Aschoff nodules. therefore they are not characteristic of

rheumatic heart disease Rheumatic fever (RF) is an inflammatory disease that can involve the heart, joints, skin, and brain. The disease typically develops two to four weeks after a streptococcal throat infection. Signs and symptoms include fever, multiple painful jo ...

Stage 3. Late fibrosis stage. It is the stage of healing by which the fibrosis of the Aschoff nodules occur in 12 to 16 weeks after the illness. The nodule becomes oval or fusiform in shape about 200 micrometer x 600 micrometer in width and length. With passage of months and years the Aschoff nodules becomes less cellular and collagenous tissue is increased. Eventually it is replaced by a small fibrocollagenous scar with little cellularity frequently located

perivascular Mural cells are the vascular smooth muscle cells (vSMCs), and pericytes, of the microcirculation. Both types are in close contact with the endothelial cells lining the capillaries, and are important for vascular development and stability. Mural cel ...

ly.

History

The Aschoff bodies were discovered independently by the German pathologist

1904K. A. L. Aschoff. Zur Myocarditisfrage. Verhandlungen der deutschen pathologischen Gesellschaft, Stuttgart, 1904, 8: 46-53. Translated in Willius & Keys, Cardiac Classics, 1941, pp. 733-739. and one year later by Paul Rudolf Geipel.

References

{{DEFAULTSORT:Aschoff Body Histopathology