Primary sclerosing cholangitis: diagnosis

Laboratory research

When examining blood serum, signs of cholestasis are revealed with an increase in alkaline phosphatase activity 3 times higher than normal. The level of bilirubin varies considerably and in rare cases exceeds 10 mg% (170 μmol / l). As in all patients with cholestasis, the content of copper in serum and ceruloplasmin, as well as copper in the liver, increases. The levels of y-globulins and IgM increase in 4 0-50% of cases.

In the serum, low titres of antibodies to smooth muscle and antinuclear antibodies can be detected, but antimitochondrial antibodies are absent.

Occasionally, eosinophilia is observed.

Histological changes in the liver

In the perfusion study of the bile ducts of the liver removed during transplantation, tubular and saccular enlargement of the intrahepatic ducts is revealed, and their transformation into fibrous cords until complete disappearance.

Histologically, the portal zones are infiltrated with small and large lymphocytes, neutrophils, sometimes macrophages and eosinophils. Around the interlobular bile ducts revealed periductular inflammation, in some cases accompanied by desquamation of the epithelium. Inside the lobules inflammatory infiltration can occur, Kupffer's cells are swollen and protrude into the lumen of the sinusoids. Cholestasis is noticeable only with severe jaundice.

Over time, fibrosis develops in the portal tracts, causing bundles of connective tissue around the small ducts in the form of bulbous husks. Remains of the bile ducts can be detected only in the form of fibrous rings. Portal zones become star-shaped.

Histological changes are non-specific, but a reduced number of bile ducts, tubule proliferation, and significant copper deposits along with step necroses allow suspected primary sclerosing cholangitis and serve as the basis for cholangiography.

Histological examination of the common bile duct reveals fibrosis and inflammation that do not have diagnostic significance.

Cholangiography

Endoscopic retrograde cholangiopancreatography is the method of choice, although transhepatic cholangiography can be used successfully. Diagnostic criterion is the detection of areas of uneven narrowing and widening (sharpness) of intra- and extrahepatic bile ducts.

Strictures have a small length (0.5-2 cm), cause bending of the ducts and alternate with unchanged or slightly widened sections of the bile ducts. In the course of the common bile duct, protrusions resembling diverticula can be found.

With cholangiography, lesion can be limited only to intrahepatic, only extrahepatic ducts or even only one hepatic duct.

With lesions of small ducts on cholangiograms, there are no changes.

Visualization diagnostic methods

At ultrasound examination, the thickening of the walls of the bile ducts is revealed, with computed tomography - the minimally enlarged sections during the bile ducts; a similar pattern is observed with a rare diffuse cholangiocarcinoma.

Cholangiocarcinoma

Cholangiocarcinoma occurs in about 10% of patients with primary sclerosing cholangitis. It can complicate the damage of both small and large ducts and is usually observed in patients with ulcerative colitis. Survival is an average of 12 months.

Cholangiocarcinoma is very difficult to diagnose. It can be suspected if the patient develops jaundice. In favor of cholangiocarcinoma in the case of cholangiography, local dilatation of the bile ducts, progressive stricture of them and intra-flow polyps show. The possibility of cholangiocarcinoma can be thought of with thrombophlebitis of superficial veins and dysplasia of the epithelium of bile ducts in areas where the tumor is absent. Mandatory cholangiography with a cytological examination of bile and scrapes, as well as a biopsy of the bile duct. It is also useful to determine serum tumor markers, such as CA 19/9. The accuracy of diagnosis with the combination of CA 19/9 and carcinoembryonic antigen reaches 86%.

Diagnostics

Diagnostic criteria

• the presence of obstructive jaundice of a progressive type;
• absence of stones in the biliary tract (previously there were no operations in the hepatobiliary zone);
• detection of prilaparotomy of common thickenings and narrowing of extrahepatic bile ducts, patency of their intrahepatic sections is confirmed by operating cholangiography;
• absence of malignant neoplasms;
• Exclusion of primary biliary cirrhosis according to the morphological study of liver biopsy.

To distinguish primary sclerosing cholangitis from primary biliary cirrhosis allow the results of cholangiography and the absence of antimitochondrial antibodies. The onset of primary sclerosing cholangitis may resemble chronic hepatitis, especially in children, or cryptogenic cirrhosis. The key to the diagnosis is an increase in the activity of alkaline phosphatase; The diagnosis is verified using cholangiography.

In the presence of an anamnesis of operation on the biliary tract or the detection of gallstones, secondary sclerosing cholangitis, which develops as a result of postoperative strictures of bile ducts or choledocholithiasis, should be excluded.

In addition, primary sclerosing cholangitis should be differentiated with ischemic damage of the bile ducts as a result of the administration of floxuridine to the hepatic artery, congenital bile duct anomalies, infectious cholangiopathy in AIDS patients or those who underwent liver transplantation, as well as bile duct tumors and histiocytosis X.

Laboratory data

1. General blood test: increased ESR, signs of anemia, leukocytosis.
2. Urinalysis is a positive reaction to bilirubin.
3. Biochemical blood test: increase in the content of alkaline phosphatase, bilirubin (mainly conjugated), alanine aminotransferase in the blood, an increase in the copper content is possible.

Instrumental data

1. Laparoscopy: the liver in the initial stages may look unchanged, later formed cirrhosis. Its color is from dark cherry to green, but less intense than with subhepatic cholestasis. On the surface of the liver, star-shaped entanglements are associated with pronounced fibrosis, small nodes of purple-red or black, resembling metastases. In the far-reaching stages macroscopically there is a "large green liver", caused by chronic cholestasis, but on its surface there are no enlarged bile capillaries, characteristic for obstructive jaundice.
2. Retrograde endoscopic cholangiopancreatography: the most simple and convenient type of study to confirm the diagnosis. Cholangiograms show beadlike changes in large intrahepatic bile ducts, combined with depletion in small intrahepatic ducts (a picture resembling a "dead" tree). Characteristic, chaotically scattered, short finger-like constrictions, replaced by normal bile ducts, and combined with widespread strictures, diverticular malocclusion protrusions and microsegases are described, which causes unevenness of the duct walls. In addition to intrahepatic, extrahepatic bile ducts are affected. The absence of supernotopic enlargement is an important sign of primary stenosing cholangitis, which distinguishes it from secondary cholangitis.
3. A liver biopsy: a fibrous inflammation of the bile ducts, possibly an increased content of copper.

[1], [2], [3], [4]