Autoimmune heart disease
Encyclopedia
Autoimmune
heart
disease
s are the effects of the body's own immune
defense system mistaking cardiac antigens as foreign and attacking them leading to inflammation
of the heart as a whole, or in parts. The commonest form of autoimmune heart disease is rheumatic heart disease or rheumatic fever
.
. Autoantibodies
or auto-toxic T lymphocyte
mediated tissue destruction. The process is aided by neutrophils, the complement system
, tumor necrosis factor alpha, etc.
Etiologically, these are most commonly seen in children with a history of sore throat
caused by a streptococcal infection
. This is similar to the post-streptococcal glomerulonephritis
. Here, the anti-bacterial antibodies cross react with the heart antigens causing inflammation.
Inflammatory damage leads to the following:
. These are covered in their relevant articles.
Autoimmunity
Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an autoimmune disease...
heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
s are the effects of the body's own immune
Immunity (medical)
Immunity is a biological term that describes a state of having sufficient biological defenses to avoid infection, disease, or other unwanted biological invasion. Immunity involves both specific and non-specific components. The non-specific components act either as barriers or as eliminators of wide...
defense system mistaking cardiac antigens as foreign and attacking them leading to inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
of the heart as a whole, or in parts. The commonest form of autoimmune heart disease is rheumatic heart disease or rheumatic fever
Rheumatic fever
Rheumatic fever is an inflammatory disease that occurs following a Streptococcus pyogenes infection, such as strep throat or scarlet fever. Believed to be caused by antibody cross-reactivity that can involve the heart, joints, skin, and brain, the illness typically develops two to three weeks after...
.
Mechanism and Etiology
These are the typical mechanisms of autoimmunityAutoimmunity
Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an autoimmune disease...
. Autoantibodies
Autoantibody
An autoantibody is an antibody manufactured by the immune system that is directed against one or more of the individual's own proteins. It is derived from the Greek "auto" which means "self", "anti" which means "against" and "body"...
or auto-toxic T lymphocyte
T cell
T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...
mediated tissue destruction. The process is aided by neutrophils, the complement system
Complement system
The complement system helps or “complements” the ability of antibodies and phagocytic cells to clear pathogens from an organism. It is part of the immune system called the innate immune system that is not adaptable and does not change over the course of an individual's lifetime...
, tumor necrosis factor alpha, etc.
Etiologically, these are most commonly seen in children with a history of sore throat
Sore throat
A sore throat or throat pain is a common physical symptom usually caused by acute pharyngitis, or throat inflammation, though it also occurs in a number of other situations, such as post trauma and in diphtheria. It can cause mild to extreme pain....
caused by a streptococcal infection
Streptococcus
Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
. This is similar to the post-streptococcal glomerulonephritis
Glomerulonephritis
Glomerulonephritis, also known as glomerular nephritis, abbreviated GN, is a renal disease characterized by inflammation of the glomeruli, or small blood vessels in the kidneys...
. Here, the anti-bacterial antibodies cross react with the heart antigens causing inflammation.
Inflammatory damage leads to the following:
- PericarditisPericarditisPericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of...
: Here the pericardiumPericardiumThe pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...
gets inflamed. Acutely, it can cause pericardial effusionEffusionIn physics, effusion is the process in which individual molecules flow through a hole without collisions between molecules. This occurs if the diameter of the hole is considerably smaller than the mean free path of the molecules...
leading to cardiac tamponadeCardiac tamponadeCardiac tamponade, also known as pericardial tamponade, is an emergency condition in which fluid accumulates in the pericardium ....
and death. After healing, there may be fibrosisFibrosisFibrosis is the formation of excess fibrous connective tissue in an organ or tissue in a reparative or reactive process. This is as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue...
and adhesionAdhesionAdhesion is any attraction process between dissimilar molecular species that can potentially bring them in close contact. By contrast, cohesion takes place between similar molecules....
of the pericardium with the heart leading to constriction of the heart and reduced cardiac function. - MyocarditisMyocarditisMyocarditis is inflammation of heart muscle . It resembles a heart attack but coronary arteries are not blocked.Myocarditis is most often due to infection by common viruses, such as parvovirus B19, less commonly non-viral pathogens such as Borrelia burgdorferi or Trypanosoma cruzi, or as a...
: Here the muscle bulk of the heart gets inflamed. Inflamed muscles have reduced functional capacity. This may be fatal, if left untreated as is in a case of pancarditis. On healing, there will be fibrosis and reduced functional capacity. - EndocarditisEndocarditisEndocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...
: Here the inner lining of the heart is inflamed, including the heart valves. This may cause a valve prolapseValvular heart diseaseValvular heart disease is any disease process involving one or more of the valves of the heart . Valve problems may be congenital or acquired...
, adhesion of the adjacent cusps of these valves and occlusion of the flow tracts of blood through the heartHeartThe heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
causing diseases called valve stenosisValvular heart diseaseValvular heart disease is any disease process involving one or more of the valves of the heart . Valve problems may be congenital or acquired...
.
Specific Clinical Manifestations
These depend on the amount of inflammationInflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
. These are covered in their relevant articles.
- Acute: Heart failure; pericardial effusion; etc.
- Chronic: Valve diseases as noted above; Reduced cardiac outputCardiac outputCardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
; Exercise intolerance.
Therapy
Intensive cardiac care and immuno-suppressives including corticosteroids are helpful in the acute stage of the disease. Chronic phase has, mainly debility control and supportive care options.Also Read
- AutoimmunityAutoimmunityAutoimmunity is the failure of an organism to recognize its own constituent parts as self, which allows an immune response against its own cells and tissues. Any disease that results from such an aberrant immune response is termed an autoimmune disease...
- HeartHeartThe heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
- GlomerulonephritisGlomerulonephritisGlomerulonephritis, also known as glomerular nephritis, abbreviated GN, is a renal disease characterized by inflammation of the glomeruli, or small blood vessels in the kidneys...