Jd Hawkins Biography & Facts
Amyloidosis is a group of diseases in which abnormal proteins, known as amyloid fibrils, build up in tissue. There are several types with varying symptoms; signs and symptoms may include diarrhea, weight loss, feeling tired, enlargement of the tongue, bleeding, numbness, feeling faint with standing, swelling of the legs, or enlargement of the spleen.There are about 30 different types of amyloidosis, each due to a specific protein misfolding. Some are genetic while others are acquired. They are grouped into localized forms, and systemic ones. The four most common types of systemic amyloidosis are light chain (AL), inflammation (AA), dialysis-related (Aβ2M), and hereditary and old age (ATTR and familial amyloid polyneuropathy).Diagnosis may be suspected when protein is found in the urine, organ enlargement is present, or problems are found with multiple peripheral nerves and it is unclear why. Diagnosis is confirmed by tissue biopsy. Due to the variable presentation, a diagnosis can often take some time to reach.Treatment is geared towards decreasing the amount of the involved protein. This may sometimes be achieved by determining and treating the underlying cause. AL amyloidosis occurs in about 3–13 per million people per year and AA amyloidosis in about 2 per million people per year. The usual age of onset of these two types is 55 to 60 years old. Without treatment, life expectancy is between six months and four years. In the developed world about 1 per 1,000 people die annually from amyloidosis. Amyloidosis has been described since at least 1639.
Signs and symptoms
The presentation of amyloidosis is broad and depends on the site of amyloid accumulation. The kidney and heart are the most common organs involved.
Amyloid deposition in the kidneys can cause nephrotic syndrome, which results from a reduction in the kidney's ability to filter and hold on to proteins. The nephrotic syndrome occurs with or without elevations in creatinine and blood urea concentration, two biochemical markers of kidney injury. In AA amyloidosis, the kidneys are involved in 91–96% of people, symptoms ranging from protein in the urine to nephrotic syndrome and rarely chronic kidney disease.
Amyloid deposition in the heart can cause both diastolic and systolic heart failure. EKG changes may be present, showing low voltage and conduction abnormalities like atrioventricular block or sinus node dysfunction. On echocardiography, the heart shows a restrictive filling pattern, with normal to mildly reduced systolic function. AA amyloidosis usually spares the heart.Cardiac amyloidosis can present with symptoms of heart failure including shortness of breath, fatigue, and edema. As cardiac amyloidosis progresses, the amyloid deposition can affect the heart’s ability to pump and fill blood as well as its ability to maintain normal rhythm, which leads to worsening heart function and decline in people’s quality of life.
People with amyloidosis do not get central nervous system involvement but can develop sensory and autonomic neuropathies. Sensory neuropathy develops in a symmetrical pattern and progresses in a distal to proximal manner. Autonomic neuropathy can present as orthostatic hypotension but may manifest more gradually with nonspecific gastrointestinal symptoms like constipation, nausea, or early satiety.
Accumulation of amyloid proteins in the liver can lead to elevations in serum aminotransferases and alkaline phosphatase, two biomarkers of liver injury, which is seen in about one third of people. Liver enlargement is common. In contrast, spleen enlargement is rare, occurring in 5% of people. Splenic dysfunction, leading to the presence of Howell-Jolly bodies on blood smear, occurs in 24% of people with amyloidosis. Malabsorption is seen in 8.5% of AL amyloidosis and 2.4% of AA amyloidosis. One suggested mechanism for the observed malabsorption is that amyloid deposits in the tips of intestinal villi (fingerlike projections that increase the intestinal area available for absorption of food), begin to erode the functionality of the villi, presenting a sprue-like picture.
Both the thyroid and adrenal glands can be infiltrated. It is estimated that 10–20% of individuals with amyloidosis have hypothyroidism. Adrenal infiltration may be harder to appreciate given that its symptoms of orthostatic hypotension and low blood sodium concentration may be attributed to autonomic neuropathy and heart failure."Amyloid deposits occur in the pancreas of patients with diabetes mellitus, although it is not known if this is functionally important. The major component of pancreatic amyloid is a 37-amino acid residue peptide known as islet amyloid polypeptide or 'amylin.' This is stored with insulin in secretory granules in B cells and is co secreted with insulin." (Rang and Dale's Pharmacology, 2015.)
Amyloid proteins deposit most commonly inside the knee, followed by hands, wrists, elbow, hip, and ankle, causing joint pain. In males with advanced age (>80 years), there is significant risk of wild-type transthyretin amyloid deposition in synovial tissue of knee joint. In beta 2-microglobulin amyloidosis, males have high risk of getting carpal tunnel syndrome. Aβ2MG amyloidosis (Hemodialysis associated amyloidosis) tends to deposit in synovial tissue, causing chronic inflammation of the synovial tissue in knee, hip, shoulder and interphalangeal joints. Amyloid light chains deposition in shoulder joint causes enlarged shoulders, also known as "shoulder pad sign". Amyloid light chain depositions can also cause bilateral symmetric polyarthritis.The deposition of amyloid proteins in the bone marrow without causing plasma cell dyscrasias is called amyloidoma. It is commonly found in cervical, lumbar, and sacral vertebrae. Those affected may be presented with bone pain due to bone lysis, lumbar paraparesis, and a variety of neurological symptoms. Vertebral fractures are also common.
A rare development is amyloid purpura, a susceptibility to bleeding with bruising around the eyes, termed "raccoon-eyes", caused by amyloid deposition in the blood vessels and reduced activity of thrombin and factor X, two clotting proteins that lose their function after binding with amyloid.
Amyloid deposits in tissue can cause enlargement of structures. Twenty percent of people with AL amyloidosis have an enlarged tongue, that can lead to obstructive sleep apnea, difficulty swallowing, and altered taste. Tongue enlargement does not occur in ATTR or AA amyloidosis. Deposition of amyloid in the throat can cause hoarseness.
Amyloidoses can be considered protein misfolding diseases. The vast majority of proteins that have been found to form amyloid deposits are secreted proteins, so the misfolding and formation of amyloid occurs outside cells, in the extracellular space. Of the 37 proteins so far identified as being vulnerable to amyloid.... Discover the Jd Hawkins popular books. Find the top 100 most popular Jd Hawkins books.