Liver Amyloidosis

What is Liver Amyloidosis?

Isolated liver amyloidosis is very rare. Amyloid is usually deposited simultaneously in the liver, kidneys, adrenal glands, spleen, intestines, and other organs.

Causes of Liver Amyloidosis

The development of amyloidosis is associated with impaired protein-synthetic function of the reticulo-endothelial system, the accumulation in the blood plasma of abnormal proteins that serve as autoantigens and cause the formation of autoantibodies. As a result of the interaction of the antigen with the antibody, coarse-dispersed proteins are involved in the formation of amyloid. Deposing in tissues (for example, in the walls of blood vessels, glandular, etc.), amyloid replaces functionally specialized elements of the organ, which leads to the death of this organ.

Pathogenesis during Amyloidosis of the Liver

In the development of amyloidosis, an important role is played by immune disorders, changes in protein metabolism. According to modern concepts, at least some types of amyloid are tissue deposits of immunoglobulin fragments. Back in 1931, Magnus-Levy discovered in patients with myeloma a frequent combination of Bens-Jones protein isolation and amyloid deposition. The amino acid composition of Bens-Jones protein is almost identical to amyloid. There are reports of structural commonality of fragments of polypeptide chains of immunoglobulins and proteins of amyloid fibrils in amyloidosis. Evidence has been obtained of the basic significance of cellular immune responses in the pathogenesis of amyloidosis.

In the pathogenesis of primary amyloidosis, the main role is played by violations of the synthesis of immunoglobulins as a result of mutation of the plasma cell.

In the formation of some varieties of amyloid an important role is played by the complement system (fractions C1, C3 and C4). It is believed that immune complexes are involved in the development of reactive amyloidosis.

The liver is involved in the pathological process in these three forms of amyloidosis. With reactive amyloidosis, the liver is almost always affected, with hereditary – in 50% of cases.

The surface of the liver is usually smooth, pale brown, dense substance, waxy. It is noteworthy that amyloidosis does not lead to cirrhosis of the liver.

According to V.V. Serov, I.A. Shamov (1977), reactive systemic amyloidosis is characterized by an initial deposition of amyloid in the perisinusoidal Disse space of lobular centers, then a gradual spread to the periphery. With hereditary and amyloidosis associated with changes in immunocytes, amyloid deposits are most pronounced in the vessels and stroma of the portal tracts.

Based on the localization of amyloid, three histological types of hepatic amyloidosis are distinguished: Type I – intralobular; Type II – periportal; Type III – perivascular, mixed.

Amyloid with intralobular type squeezes and deforms the hepatic beams, which leads to their atrophy. Separate groups of hepatocytes are immured by amyloid and destroyed. In types II and III of liver amyloidosis, the liver lobules are preserved; amyloid is deposited in the vessels and stroma of the portal tracts.

The most specific for amyloid are its anisotropy and dichroism after staining with Congo red or red Sirius. Very specific secondary fluorescence of amyloid in ultraviolet light after staining with thioflavin T or S. Electron-microscopic examination is essential to clarify the localization of amyloid and the degree of hepatocyte damage.

Symptoms of Amyloidosis of the Liver

The most common symptom is hepatosplenomegaly, which, according to various authors, is found in 32-100% of cases. The liver is dense, slightly painful, significantly increases in the late stage of the disease.

Jaundice is rare, it is not intensive, M. Leyy et al. (1974) examined 490 patients with amyloidosis and found jaundice in 4.7% of patients. The causes of jaundice in amyloidosis are unclear, since in many cases the deposition of even a large amount of amyloid does not lead to its development. Jaundice with amyloidosis can be caused by hepatocellular insufficiency and intrahepatic cholestasis. Perhaps the development of intrahepatic obstructive jaundice on the background of primary liver amyloidosis. In these cases, the clinical picture is dominated by the phenomena of biliary obstruction, expressed in severe skin itch, acholichny chair, high levels of bilirubin, cholesterol and alkaline phosphatase in blood serum.

Laboratory research reveals characteristic protein shifts, especially alpha2-globulinemia, immune disorders, increased serum alkaline phosphatase activity. Other functional tests are little changed.

Diagnosis of Liver Amyloidosis

Such minor clinical symptoms as dry, pale, porcelain skin, macroglossia are of known importance for the detection of amyloidosis. In connection with the frequent damage of the kidneys, it is advisable to re-examine the urine, which can detect proteinuria. Hepatolienal syndrome without prior hepatic history should also make the doctor think about possible amyloidosis. Crucial for the diagnosis is needle biopsy of the liver. Amyloid is found in the form of homogeneous masses, painted Congo red in pink.

The diagnosis becomes more reliable with simultaneous detection of amyloid in the liver, intestines, gums.

Treatment of Liver Amyloidosis

Liver hydrolysates are shown (symptoms, prohepar, ripazone). In the initial stages, especially with systemically reactive amyloidosis, 4-aminocholine preparations, chloroquine (delagil) and plaquenil, are prescribed.

With primary amyloidosis, colchicine is used at a dose of 1.5-2 mg / day. The mechanism of action is associated with an indirect inhibitory effect on the function of leukocytes.

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