Index
It is a group of disparate conditions characterized by the extracellular deposition of insoluble fibrils composed of disaggregated proteins.
These proteins can accumulate locally, causing relatively few symptoms, widely involving multiple organs, and causing severe multi-organ failures.
Analysis can occur due to various infectious, inflammatory, or malignant conditions. The diagnosis is made by biopsy of the affected tissue; The amyloidogenic protein is typified using different immunohistological and biochemical techniques. The treatment varies with the type of Analysis.
Amyloid deposits are small insoluble fibrils (approximately 10 nm in diameter) that form pleated beta-sheets that can be identified by X-ray diffraction.
In addition to the fibrillar amyloid protein, the deposits also contain serum amyloid P component and glycosaminoglycans. Amyloid fibrils are made of misfolded proteins added in oligomers and fibrils.
A series of normal proteins (wild type) and mutants are susceptible to such aggregation (amyloidogenic proteins), representing the wide variety of causes and types of amyloidosis.
For amyloidosis to develop and the production of amyloidogenic proteins, there is likely a failure of the standard clearance mechanisms for these misfolded proteins.
Amyloid deposits are metabolically inert but physically interfere with the structure and function of the organ. However, some prefibrillar oligomers of amyloidogenic proteins have direct cellular toxicity, an essential component of the pathogenesis of the disease.
The amyloid deposits are stained pink with hematoxylin and eosin. They contain carbohydrate components stained with periodic acid-Schiff dye or Alcian blue. Still, most have green-apple birefringence under polarized light microscopy after staining with Congo red.
On inspection during an autopsy, the affected organs may appear waxy.
Symptoms and signs.
The symptoms and signs of systemic amyloidosis are nonspecific, which often results in delays in diagnosis. The suspicion of Amilosis should be increased in patients with a progressive process of multisystem disease.
Renal amyloid deposits typically occur in the glomerular membrane, leading to proteinuria, but in approximately 15% of cases, the tubules are affected, causing azotemia with minimal proteinuria.
These processes can progress to nephrotic syndrome with marked hypoalbuminemia, edema, and anasarca or terminal kidney disease.
Liver involvement causes painless hepatomegaly, which can be massive. Although jaundice is rare, liver function tests suggest intrahepatic cholestasis with elevated alkaline phosphatase and subsequent bilirubin.
Occasionally, portal hypertension develops, with resultant esophageal varices and ascites. The involvement of the airways leads to dyspnea, wheezing, hemoptysis, or obstruction of the respiratory tract.
The infiltration of the myocardium causes restrictive cardiomyopathy, which eventually leads to diastolic dysfunction and heart failure, Cardiac arrest, or arrhythmia. Hypotension is common.
Peripheral neuropathy with paresthesias of the fingers and toes is a common manifestation in Analysis. The autonomic neuropathy can cause orthostatic hypotension, erectile dysfunction, abnormalities of sweating, and alterations of motility.
Cerebrovascular amyloid angiopathy most often causes spontaneous cerebral hemorrhage, but some patients have brief transient neurological symptoms.
It can cause abnormalities of esophageal and small and large bowel motility. Gastric atony, malabsorption, bleeding, or pseudo-obstruction may also occur.
Amyloidosis of the thyroid gland can cause a firm, symmetric, and nodule-free borer that resembles that found in Hashimoto’s thyroiditis. Other endocrinopathies may also occur.
The pulmonary involvement can be characterized by focal pulmonary nodules, tracheobronchial lesions, or diffuse alveolar deposits. Vitreous amyloid opacities and staggered bilateral pupillary margins develop into several hereditary amyloidoses.
Other manifestations include bruising around the eyes (raccoon eyes) caused by amyloid deposits in the blood vessels. Amyloid deposits cause weakening of the blood vessels, which can rupture after minor trauma, such as sneezing or coughing.
Diagnosis
- Biopsy.
- Amyloid typography.
- Tests for the participation of organs.
The diagnosis of Analysis is made by demonstrating fibrillar deposits in an involved organ. Subcutaneous abdominal fat aspiration is positive in approximately 80% of patients.
If the result of the fat biopsy is negative, a biopsy of a clinically involved organ should be performed. The tissue sections are stained with red dye and examined with a polarizing microscope for characteristic birefringence.
10 nm fibrils that are not branching may also be recognized by electron microscopy in heart or kidney biopsy samples.
Amyloid typography.
After the amylose has been confirmed by biopsy, the type is determined using various techniques. For some amylose, immunohistochemistry or immunofluorescence can be diagnostic, but false-positive typing results are produced.
Other practical techniques include gene sequencing and biochemical identification by mass spectrometry.
If suspected, patients should be evaluated for an underlying plasma cell disorder using quantitative measurement of serum-free immunoglobulin light chains.
It is also essential for qualitatively detecting serum or monoclonal urine light chains using immunofixation electrophoresis (serum protein electrophoresis and protein electrophoresis in urine are insensitive to inpatients).
I would also apply a bone marrow biopsy with flow cytometry or immunohistochemistry to establish the clonality of the plasma cells.
Patients with> 10% clonal plasma cells should be tested to see if they meet the criteria for multiple myeloma, including detection of lytic bone lesions, anemia, renal failure, and hypercalcemia.
Forecast.
The prognosis depends on the type of amylose and the organ system involved, but with proper disease and support care, many patients have an excellent life expectancy.
Analysis complicated by severe cardiomyopathy still has the poorest prognosis, with an average survival of <1 year.
Untreated amyloidosis usually progresses to end-stage heart or neurological disease within 5 to 15 years. It was thought to have the slowest progression of any systemic amyloidosis affecting the heart; However, patients progress to symptomatic heart failure and death within a few years of diagnosis.
The prognosis in Amilosis depends mainly on the effectiveness of the treatment of the underlying infectious, inflammatory or malignant disorder.
