Hepatic amyloidosis

Introduction Pathogenesis of hepatic venous occlusion: Hepatic sinus expansion symptoms occur in both the acute and subacute phases. In the acute phase, the liver is enlarged and the surface is smooth, and lymphatic vessel expansion and "liver crying" signs are seen. Under the light microscope, the central vein and the inferior venous intima were significantly swollen, the lumen was narrowed or occluded, the blood flow was blocked, and the hepatic sinus was obviously dilated and congested with varying degrees of hepatocyte turbidity, swelling and necrosis. Hepatocytes disappeared in the area of necrosis, residual reticular fiber scaffolds, red blood cells infiltrated into the hepatic sinus and Dissel's space, and typical hemorrhagic necrosis changes. In the subacute stage, the surface of the liver is reticulated, and the central vein and the inferior venous endothelium are hyperplasia and thickening, forming fibrosis and stenosis and occlusion. In this period, there may still be hepatic sinus expansion, hemorrhage and hemorrhagic hepatocyte necrosis, fibrosis in the central vein, and no false leaflet formation.

Cause

(1) Causes of the disease

The etiology and pathogenesis of amyloidosis are still unclear. It is generally believed that amyloidogenic substances are mainly infiltrated between cells due to various reasons, or deposited under the basement membrane of small blood vessels, or deposited along reticular fiber scaffolds.

(two) pathogenesis

As the lesion progresses, these deposits compress and destroy these tissues leading to organ failure and death. Isolation and purification of amyloid denatured fibers for amino acid sequence analysis revealed that there are three protein types in amyloid fibrils:

AL type protein

The light chain derived from immunoglobulin (especially the variable region), the N-terminal sequence and the partial region of the immunoglobulin light chain are homologous, including the kappa type and the lambda type, and the lambda light chain is more likely to form amyloid than the kappa type. Fiber, found in primary amyloidosis and amyloid deposition associated with multiple myeloma.

2.AA type protein

It has the same N-terminal sequence as the non-immunoglobulin called AA protein. The amyloid fiber seems to be independent of the light chain. The main amyloid fiber is composed of a protein A different from immunoglobulin, probably due to the pulp. The immunoglobulin produced by the cell is transformed by the proteolytic action of the phagocytic lysosomal enzyme, which is found in the amyloid deposition syndrome associated with secondary and familial Mediterranean fever.

3.AF type protein

Amyloid fiber is mainly a normal or abnormal prealbumin complex (molecular weight 14000), usually a single amino acid replacement product of transthyretin (pre- albumin), followed by 2 microglobulin, mainly found in familial amyloid Sedimentation.

an examination

Related inspection

Liver, gallbladder, spleen CT examination

There are no specific symptoms and signs in amyloidosis. The symptoms are determined by the location of the original disease and amyloid deposits, the amount of deposition, and the organs and systems involved. The symptoms are often masked by the primary disease.

More than 95% of secondary and systemic amyloidosis have liver involvement, often manifested as hepatomegaly, upper abdominal fullness, anorexia, and a few can be severe liver enlargement (hepatic weight can reach more than 7kg). However, liver function damage is mild, occasionally portal hypertension, manifested as esophagus, gastric varices and ascites, etc., very few may have jaundice.

According to symptoms, signs and auxiliary examinations, a preliminary diagnosis of amyloidosis can be made. The diagnosis requires tissue biopsy. Skin and rectal mucosal biopsy is the most commonly used screening method. Other biopsy sites include gums, nerves, kidneys and liver. For patients with suspected primary hepatic amyloidosis, liver biopsy can be performed directly. For patients with amyloidosis with markedly enlarged liver, due to the tightness of the liver capsule, liver puncture may cause liver rupture or hepatic hemorrhage, and the clinical should be cautious. For the patients with systemic amyloidosis, most of the gastric and rectal mucosal biopsies are safe and effective.

Differential diagnosis

1, acute hepatitis: recent low fever, general fatigue, loss of appetite, accompanied by nausea, vomiting, tired of greasy, liver discomfort and urine yellow and other symptoms, no improvement after rest.

2, cirrhosis caused by various reasons: variable now is fatigue, weight loss, dull complexion, oliguria, lower extremity edema, general liver pathology found that the formation of false leaflets can be diagnosed.

3, primary or secondary liver cancer: general performance: (1) appetite significantly reduced: abdominal swelling, indigestion, sometimes nausea, vomiting; (2) right upper abdomen pain: liver area may have continuous or intermittent Pain, sometimes can be aggravated by body position changes; (3) fatigue, weight loss, unexplained fever and edema; (4) jaundice, ascites, skin itching; (5) often manifested as nosebleeds, subcutaneous hemorrhage.

4, hepatolenticular degeneration: the disease usually occurs in children and adolescents, a small number of adult hair onset age is 5 to 35 years old, more men than women. The condition develops slowly, and there may be a phased relief or aggravation, and there are also rapid progress. Clinical manifestations: Neurological and psychiatric symptoms Neurological symptoms are characterized by extrapyramidal damage, with dance-like movements, hand-foot and dystonia, and facial discomfort, mouth drooling, difficulty swallowing, dysarthria, and exercise. Slowness, tremors, muscle rigidity, etc. Tremor can be expressed as static or postural, but not as slow and rhythmic as the tremor of Parkinson's disease.

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