Amyloid deposits

Introduction Amyloid deposition: Systemic amyloidosis is a new definition of systemic amyloidosis proposed by Pipen et al. due to the deposition of amyloid in the extracellular tissue space of the system, thereby destroying the function of cells and organs. Yes: Amyloidosis is a group of deposition syndromes of amyloid caused by different factors such as genetic degeneration and infection. Because the deposited amyloid and affected organs are different, the clinical manifestations are not uniform. Commonly affected organs such as liver, kidney, nerve, heart, gastrointestinal tract and other affected tissues are more common with skin tongue and lymph nodes. All tissues and organs in the body can be affected, but not necessarily clinically.

Cause

The exact mechanism of amyloid formation has not been fully clarified, but the prerequisite for the deposition of amyloid fibrils is that the precursor protein is produced in excessive amounts or structural abnormalities, and the precursor protein becomes easily folded into reverse after incomplete degradation. Parallel -sheet structure fragments, while in familial amyloid polyneuropathy and hemodialysis-related amyloidosis, intact undegraded TTR and 2-M molecules can also form amyloid fibrils . The primary structure of a protein is important for its ability to form amyloid fibrils. For example, in the case of hereditary amyloidosis, a single amino acid substitution can turn a wild-type molecule that cannot form an amyloid into a fibril-producing mutation. Type of molecule. In addition, there are other factors that affect the deposition process and distribution of fibrils. The so-called amyloid enhancing factor (AEF) may be related to clinical individual differences. The mechanism of amyloid formation.

an examination

Related inspection

Adrenal CT examination of kidney CT

1. In addition to detailed medical history, you should focus on past history and family history: in the past history, you should ask whether there is rheumatoid arthritis, inflammatory bowel disease tuberculosis, suppurative osteomyelitis, and history of dialysis treatment of empyema. .

The enlargement of the skin around the eyelids, unexplained heart enlargement and heart failure, hepatomegaly, proteinuria, swollen lymphadenopathy, refractory pleural effusion and whole blood cell reduction should consider the possibility of systemic amyloidosis.

2. Laboratory tests that are helpful in the diagnosis of systemic amyloidosis include: 1 Bene-Jone protein examination in urine. 2 bone marrow puncture smear examination, systemic amyloidosis AL type of bone marrow immature and mature plasma cells accounted for more than 15%, while can see myeloma cells. The 3AF type measures plasma-associated variant proteins.

3. The diagnosis is to confirm the deposition of amyloid in the interstitial space. The most reliable method is to perform biopsy and pathological biopsy from the diseased tissue.

Differential diagnosis

1. AL-type amyloidosis and multiple myeloma AL-type amyloidosis bone marrow examination often shows an increase in plasma cell count, and both amyloid proteins are AL-type, making it difficult for multiple bone marrow at one time Tumor identification. If the number of bone marrow plasma cells is less than 25%, there is a small amount of monoclonal protein in the blood or urine, and there is no associated anemia, hypercalcemia and osteolytic damage, the possibility of AL amyloidosis is greater.

2. AA-type amyloidosis and its various causes should be noted.

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