Takayasu's arteritis
Encyclopedia
Takayasu's arteritis
Arteritis
Arteritis is inflammation of the walls of arteries, usually as a result of infection or auto-immune response.-Types:Some disorders have arteritis as their main feature...

(also known as "aortic arch syndrome", "nonspecific aortoarteritis" and the "pulseless disease") is a form of large vessel granulomatous vasculitis
Vasculitis
Vasculitis refers to a heterogeneous group of disorders that are characterized by inflammatory destruction of blood vessels. Both arteries and veins are affected. Lymphangitis is sometimes considered a type of vasculitis...

 with massive intimal fibrosis
Fibrosis
Fibrosis 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 vascular narrowing affecting often young or middle-aged women of Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

n descent. It mainly affects the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...

 (the main blood vessel leaving the heart) and its branches, as well as the pulmonary arteries. Females are about 8-9 times more likely to be affected than males. Patients often notice the disease symptoms between 15 and 30 years of age. In the Western world
Western world
The Western world, also known as the West and the Occident , is a term referring to the countries of Western Europe , the countries of the Americas, as well all countries of Northern and Central Europe, Australia and New Zealand...

, atherosclerosis
Atherosclerosis
Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

 is a more frequent cause of obstruction of the aortic arch vessels than Takayasu's arteritis. Takayasu's arteritis is similar to other forms of vasculitis, including giant cell arteritis. Due to obstruction of the main branches of the aorta, including the left common carotid artery
Common carotid artery
In human anatomy, the common carotid artery is an artery that supplies the head and neck with oxygenated blood; it divides in the neck to form the external and internal carotid arteries. - Structure :...

, the brachiocephalic artery
Brachiocephalic artery
The brachiocephalic artery is an artery of the mediastinum that supplies blood to the right arm and the head and neck....

, and the left subclavian artery
Subclavian artery
In human anatomy, the subclavian arteries are two major arteries of the upper thorax , below the clavicle . They receive blood from the top of the aorta...

, Takayasu's arteritis can present as pulseless upper extremities (arms, hands, and wrists with weak or absent pulses on the physical examination) which may be why it is also commonly referred to as the "pulseless disease."

Pathophysiology

Although its etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

 is unknown, the condition is characterized by segmental and patchy granuloma
Granuloma
Granuloma is a medical term for a tiny collection of immune cells known as macrophages. Granulomas form when the immune system attempts to wall off substances that it perceives as foreign but is unable to eliminate. Such substances include infectious organisms such as bacteria and fungi as well as...

tous 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 aorta and its major derivative branches. This inflammation leads to arterial stenosis
Stenosis
A stenosis is an abnormal narrowing in a blood vessel or other tubular organ or structure.It is also sometimes called a stricture ....

, thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...

, and aneurysm
Aneurysm
An aneurysm or aneurism is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms can commonly occur in arteries at the base of the brain and an aortic aneurysm occurs in the main artery carrying blood from the left ventricle of the heart...

s. There is also irregular fibrosis of the blood vessels due to chronic vasculitis leading to sometimes massive intimal fibrosis (fibrosis of the inner section of the blood vessels). Prominent narrowing due to inflammation, granuloma, and fibrosis is often seen in arterial studies such as Magnetic resonance angiography
Magnetic Resonance Angiography
Magnetic resonance angiography is a group of techniques based on Magnetic Resonance Imaging to image blood vessels. Magnetic resonance angiography is used to generate images of the arteries in order to evaluate them for stenosis , occlusion or aneurysms...

 (MRA), computed tomography angiography
Computed tomography angiography
Computed tomography angiography is a computed tomography technique used to visualize arterial and venous vessels throughout the body. This ranges from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs.-Technique:...

 (CTA), or arterial angiography (DSA).

Symptoms

Some patients develop an initial "inflammatory phase" characterized by systemic illness with symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s of malaise
Malaise
Malaise is a feeling of general discomfort or uneasiness, of being "out of sorts", often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell"...

, fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

, night sweats
Sleep hyperhidrosis
Sleep hyperhidrosis, more commonly known as the night sweats, is the occurrence of excessive sweating during sleep. The sufferer may or may not also suffer from excessive perspiration while awake....

, weight loss
Weight loss
Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...

, arthralgia
Arthralgia
Arthralgia literally means joint pain; it is a symptom of injury, infection, illnesses or an allergic reaction to medication....

, and fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...

. There is also often anemia
Anemia
Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

 and marked elevation of the ESR
Erythrocyte sedimentation rate
The erythrocyte sedimentation rate , also called a sedimentation rate or Biernacki Reaction, is the rate at which red blood cells sediment in a period of 1 hour...

 or C-reactive protein
C-reactive protein
C-reactive protein is a protein found in the blood, the levels of which rise in response to inflammation...

 (nonspecific markers of inflammation). The initial "inflammatory phase" is often followed by a secondary "pulseless phase." The "pulseless phase" is characterized by vascular insufficiency from intimal narrowing of the vessels manifesting as arm or leg claudication
Claudication
Claudication, literally 'limping' , is a medical term usually referring to impairment in walking, or pain, discomfort or tiredness in the legs that occurs during walking and is relieved by rest. The perceived level of pain from claudication can be mild to extremely severe. Claudication is most...

, renal artery stenosis
Renal artery stenosis
Renal artery stenosis is the narrowing of the renal artery, most often caused by atherosclerosis or fibromuscular dysplasia. This narrowing of the renal artery can impede blood flow to the target kidney...

 causing hypertension, and neurological manifestations due to decreased blood flow to the brain. Of note is the function of renal artery stenosis in causation of high blood pressure: Normally perfused kidneys produce proportionate amount of a substance called renin
Renin
Renin , also known as an angiotensinogenase, is an enzyme that participates in the body's renin-angiotensin system -- also known as the Renin-Angiotensin-Aldosterone Axis -- that mediates extracellular volume , and arterial vasoconstriction...

. Stenosis of the renal arteries, causes hypoperfusion (decreased blood flow) of the juxtaglomerular apparatus
Juxtaglomerular apparatus
The juxtaglomerular apparatus is a microscopic structure in the kidney, which regulates the function of each nephron. The juxtaglomerular apparatus is named for its proximity to the glomerulus: it is found between the vascular pole of the renal corpuscle and the returning distal convoluted tubule...

, resulting in exaggerated secretion of renin
Renin
Renin , also known as an angiotensinogenase, is an enzyme that participates in the body's renin-angiotensin system -- also known as the Renin-Angiotensin-Aldosterone Axis -- that mediates extracellular volume , and arterial vasoconstriction...

, and high blood levels of aldosterone
Aldosterone
Aldosterone is a hormone that increases the reabsorption of sodium ions and water and the release of potassium in the collecting ducts and distal convoluted tubule of the kidneys' functional unit, the nephron. This increases blood volume and, therefore, increases blood pressure. Drugs that...

, eventually leading to water and salt retention and high blood pressure. The neurological symptoms of the disease vary depending on the degree, and the nature of the blood vessel obstruction and can range from lightheadedness, to seizures in severe cases. One rare but important feature of the Takayasu's arteritis is ocular
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...

 involvement in form of visual field defects, vision loss, or retinal hemorrhage Some patients with Takayasu's arteritis may present with only late vascular changes, without an antecedent systemic illness. In the late stage, weakness of the arterial walls may give rise to localized aneurysm
Aneurysm
An aneurysm or aneurism is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms can commonly occur in arteries at the base of the brain and an aortic aneurysm occurs in the main artery carrying blood from the left ventricle of the heart...

s. As with all aneurysms, possibility of rupture and vascular bleeding is existent and requires monitoring. Raynaud's phenomenon
Raynaud's phenomenon
In medicine, Raynaud's phenomenon is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other areas. This condition can also cause nails to become brittle with longitudinal ridges. Named for French physician Maurice Raynaud , the phenomenon is believed to be the...

 is commonly found in this disease, mainly due to decreased circulation of the blood to the arms.

Treatments

The great majority of patients with Takayasu’s arteritis respond to steroids such as prednisone
Prednisone
Prednisone is a synthetic corticosteroid drug that is particularly effective as an immunosuppressant drug. It is used to treat certain inflammatory diseases and some types of cancer, but has significant adverse effects...

. The usual starting dose is approximately 1 milligram per kilogram of the body weight per day (for most people, this is approximately 60 milligrams a day). Because of the significant side effects
Adverse effect (medicine)
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...

 of long-term high–dose prednisone use, the starting dose is tapered over several weeks to a dose that the physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

 feels is tolerable for the patient.

Surgical options may need to be explored for patients who do not respond to steroids. Re-perfusion of tissue can be achieved by large vessel reconstructive surgery such as bypass grafting. Grafting autologous tissue has the highest rates of success.
Percutaneous transluminal coronary angioplasty (PTCA) is not as effective in the long term but has fewer risks.

History

The first case of Takayasu’s arteritis was described in 1908 by a Japanese opthalmologist, Mikito Takayasu
Mikito Takayasu
was a Japanese ophthalmologist known for his discovery of Takayasu's arteritis.Graduating from Tokyo Imperial University in 1887, Takayasu worked at what was to become Kanazawa University School of Medicine in Kanazawa, Ishikawa...

 at the Annual Meeting of the Japan Ophthalmology Society. Takayasu described a peculiar "wreathlike" appearance of the blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...

s in the back of the eye (retina
Retina
The vertebrate retina is a light-sensitive tissue lining the inner surface of the eye. The optics of the eye create an image of the visual world on the retina, which serves much the same function as the film in a camera. Light striking the retina initiates a cascade of chemical and electrical...

). Two Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese physicians at the same meeting (Drs. Onishi and Kagoshima) also reported similar eye findings in patients whose wrist pulse
Pulse
In medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the...

s were absent. It is now known that the blood vessel malformations that occur in the retina are an angiogenic
Angiogenesis
Angiogenesis is the physiological process involving the growth of new blood vessels from pre-existing vessels. Though there has been some debate over terminology, vasculogenesis is the term used for spontaneous blood-vessel formation, and intussusception is the term for the formation of new blood...

 response to the arterial narrowings in the neck, and that the absence of pulses noted in some patients occurs because of narrowings of the blood vessels to the arms. The eye findings described by Takayasu are rarely seen in patients from North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

and British Columbia[reference missing].

External links

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