09-01-2021-1729 - Primary Biliary cholangitis cirrhosis PBC Inflammation of the bile ducts, characterized by intraepithelial lymphocytes Periductal epithelioid granulomas. Proliferation of bile ductules Fibrosis (scarring)

 Primary biliary cholangitis (PBC), previously known as primary biliary cirrhosis, is an autoimmune disease of the liver.^[1][2][3] It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build up in the liver, a condition called cholestasis. Further slow damage to the liver tissue can lead to scarring, fibrosis, and eventually cirrhosis.

• Inflammation of the bile ducts, characterized by intraepithelial lymphocytes
• Periductal epithelioid granulomas.
• Proliferation of bile ductules
• Fibrosis (scarring)

The Ludwig and Scheuer scoring systems have historically been used to stratify four stages of PBC, with stage 4 indicating the presence of cirrhosis. In the new system of Nakanuma, the stage of disease is based on fibrosis, bile duct loss, and features of cholestasis, i.e. deposition of orcein-positive granules, whereas the grade of necroinflammatory activity is based on cholangitis and interface hepatitis. The accumulation of orcein-positive granules occurs evenly across the PBC liver, which means that staging using the Nakanuma system is more reliable regarding sampling variability.

Liver biopsy for the diagnosis and staging of PBC lost favour after the evidence of a patchy distribution of the duct lesions and fibrosis across the organ. The widespread availability of noninvasive measures of fibrosis means that liver biopsy for staging of PBC is somewhat obsolete. Liver biopsy does, however, remain useful in certain settings. The main indications are to confirm the diagnosis of PBC when PBC-specific antibodies are absent and confirm a diagnosis of PBC with AIH features (i.e. overlap PBC-AIH). Liver biopsy is also useful to assess the relative contribution of each liver injury when a comorbid liver disease is present, such as non-alcoholic steatohepatitis. In patients with inadequate response to UDCA, liver biopsy may provide the explanation and could undoubtedly inform risk stratification. For example, it may identify a previously unsuspected variant syndrome, steatohepatitis, or interface hepatitis of moderate or greater severity. It is also useful in AMA and ANA-specific antibody negative cholestatic patients to indicate an alternative process, e.g. sarcoidosis, small duct PSC, adult idiopathic ductopenia.

https://en.wikipedia.org/wiki/Primary_biliary_cholangitis

In stereochemistry, an epimer is one of a pair of diastereomers.^[1] The two epimers have opposite configuration at only one stereogenic center out of at least two.^[2] All other stereogenic centers in the molecules are the same in each. Epimerization is the interconversion of one epimer to the other epimer.

Doxorubicin and epirubicin are two epimers that are used as drugs. 

Doxorubicin–epirubicin comparison

https://en.wikipedia.org/wiki/Epimer