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The acronyms and medical terms we use are listed and briefly explained below. If you can't find what you're looking for, let us know.

AASLD - American Association for the Study of Liver Diseases.


AIH - Autoimmune hepatitis.


Alanine aminotransferase (ALT) - measured in a liver blood test. See Blood tests.


Albumin - a protein measured in a liver blood test. See Blood tests.


Alkaline phosphatase (ALP) - measured in a liver blood test. See Blood tests.


ALP - alkaline phosphatase.


ALT - alanine aminotransferase.


Anastomosis - a join.


AST - aspartate aminotransferase.


Advanced liver disease - when the liver is severely damaged with a lot of scarring such that it fails to do all the jobs it's meant to do.


Aspartate aminotransferase (AST) -measured in a liver blood test. See Blood tests.


Asymptomatic - showing no symptoms.


Autoimmune hepatitis (AIH) - an autoimmune liver disease where the body’s immune system attacks its own liver cells. See Autoimmune hepatitis.


Bacterial cholangitis - an infection of the bile duct requiring urgent treatment. See Bacterial cholangitis.


Balloon dilatation - a procedure to open up the bile duct using a small balloon to widen the duct. See ERCP.


BASL - British Association for the Study of the Liver.


Bile - a greenish-yellow fluid produced by the liver to help digest fats and essential vitamins. See Overview of PSC.


Bile ducts - tubes that deliver bile from the liver to the small intestine. See Overview of PSC.


biliary - this describes the bile duct system. It is a series of tubes that drain out the bile and does actually have the appearance of a tree with lots of branches! See Overview of PSC.


Biliary tract or biliary system - refers to the liver, gallbladder, bile ducts and pancreas. See Overview of PSC.


Bilirubin - measured in a liver blood test; what makes people turn yellow if levels are very high. See Blood tests.


Biomarker - something measurable which is used as a means of assessing the severity or the progression of a biological process or disease.


BMI - body mass index. It is a measure of your weight and height. See PSC: Eating for health.


CBD - common bile duct.


CCA - cholangiocarcinoma.


Cholangiocarcinoma - bile duct cancer. See Cancer.


Cholangiocytes - cells in the bile ducts.


Cholangitis - inflammation of the bile ducts. See also bacterial cholangitis.


Cholestatic - relating to the bile ducts/biliary system.


Classical PSC - refers to PSC that affects both the large and small bile ducts. See Variants of PSC.


Coexisting disease - refers to having more than one disease at a time, also called comorbidity.


Colectomy - a surgical procedure to remove the whole of the colon/large bowel through an incision in your abdomen. See Colectomy type and PSC transplant.


Colonoscopy - an examination of your large bowel (colon). See Colonoscopy.


Common bile duct - this is the largest tube in the biliary system, sometimes abbreviated to CBD. See Overview of PSC.


Comorbidities - refers to having more than one condition or disease at the same time.


DBD - donation after brainstem death (in liver transplantation). See 'DCD liver transplant in PSC' and 'Are some liver transplant better than others?'


DCD - donation after circulatory death (in liver transplantation). See 'DCD liver transplant in PSC' and 'Are some liver transplant better than others?'


Decompensated liver - when the liver fails to do the jobs it is meant to do.


Dominant strictures (DS) - tight narrowing causing a point blockage in the extrahepatic bile ducts. Also see stricture. See Overview of PSC.


DS - dominant stricture.


Duct to duct biliary anastomosis – in transplant surgery where the bile duct of the donor liver is attached to the cut end of the bile duct in the recipient of the liver transplant. See Liver transplant.


Dysbiosis - an imbalance in the types and numbers of the (usual) microbiome.


EASL - European Association for the Study of the Liver.


ELF - Enhanced Liver Fibrosis test. See Blood tests.


End ileostomy - an opening in the tummy, which allows the gut’s contents to drain into a bag attached to the skin – created after surgery to remove the colon (also see colectomy).


Endoscopic retrograde cholangiopancreatography (ERCP) - a procedure that allows your doctor to look inside your bile ducts usually done with the purpose of treating a problem such as a blockage (stricture), stones or both in the reachable (usually extrahepatic) bile ducts. See ERCP.


Enhanced Liver Fibrosis (ELF) test - a blood test that looks at early fibrosis signs.


ERCP - Endoscopic retrograde cholangiopancreatography.


Extrahepatic bile ducts - the bile ducts outside the liver.


Fibroscan (transient elastography) - a scan that measures liver stiffness (fibrosis). See Fibroscan.


Gallbladder - a small, pouch-like organ close to your liver that stores bile. You don't need a gallbladder, so surgery to take it out is often recommended if you develop any problems with it, especially in PSC.


Gamma-Glutamyl Transferase (GGT) - measured in a liver blood test. See Blood tests.


Gastroscopy - a procedure to look inside the oesophagus, stomach and duodenum. Also called an oesophago-gastroduodenoscopy (OGD). See Gastroscopy.


GGT - Gamma-Glutamyl Transferase.


GWAS - Genome-wide association study (or studies).  See Genetics of PSC.


HCC - Hepatocellular carcinoma.


HCP - Healthcare professional.


HE - Hepatic Encephalopathy.


Hepatic encephalopathy – a state of confusion or decreased consciousness seen in liver failure. See Complications in PSC.


Hepatobiliary - relating to the liver and gallbladder, bile ducts or bile.


Hepatocellular carcinoma (HCC) - a cancer that arises in the liver (rather than one that spreads there). See Cancer.


Hepatocytes - liver cells.


HPB (hepatopancreatobiliary) - relating to the liver, pancreas or bile ducts.


IAC - IgG4-associated cholangitis.


IBD - inflammatory bowel disease.


IBD-u – inflammatory bowel disease-unspecified; this is a variant of IBD where there are some features of Crohn’s disease and some features of ulcerative colitis.


IgG4-RD - IgG4 related disease.


IgG4-SC - IgG4 related sclerosing cholangitis.


Incidence - how many people are newly diagnosed (usually each year). See 'Who gets PSC?'


Immune-mediated disease - a disease characterised by overactive or irregular immune system activity.


Inflammatory bowel disease (IBD) - a long-term condition featuring inflammation in the bowels. See Inflammatory bowel disease.


INR - international normalised ratio.


International normalised ratio (INR) - provides a measure of the blood’s ability to clot compared with ‘normal’ blood clotting time. See Blood tests.


Intrahepatic bile ducts - the bile ducts inside the liver. See Overview of PSC.


IPAA (Ileal-pouch anal anastomosis) - see Pouch


IPSCSG - International PSC Study Group.


Jaundice - a yellowish tinge to the skin, often seen in the whites of the eyes caused by a build-up of bilirubin in the blood and tissues. See Complications in PSC.


LDLT - live donor liver transplantation.


Live donor liver transplantation (LDLT) - where a living person donates part of their liver for a transplant operation. See Can someone I know donate their liver to me?


LTx - liver transplantation. See Liver transplantation for PSC.


Machine perfusion - a technology that is used in transplantation to better preserve donor livers prior to them being implanted into the recipient of the liver transplant. See Machine perfusion.


Magnetic resonance cholangiopancreatography (MRCP) - a type of MRI scan that looks at the bile and pancreas ducts. See MRCP scans.


Magnetic resonance imaging (MRI) - a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body. It may be performed with contrast material injected into the bloodstream to better identify the hepatobiliary structures. See MRCP scans.


MDT - multidisciplinary team. This usually refers to a meeting of different experts.


MELD (Model for End-Stage Liver Disease) - a score to estimate the severity of liver disease in patients with advanced liver disease.


Microbiome - a collection of different microbes in the digestive system (intestinal microbiota), such as bacteria, yeasts, fungi, viruses and protozoans. See 'What is the cause of PSC?'


MRCP - Magnetic resonance cholangiopancreatography.


MRI - Magnetic resonance imaging (MRI).


NLOS (National Liver Offering Scheme) - a national scheme to identify the most suitable person waiting for a liver transplant when a donor liver becomes available by selecting the recipient who would be expected to have the greatest benefit (at 5 years) from the time of transplant. See National Liver Offering Scheme.


Opt-out - this refers to giving consent for organ donation. An opt-out or deemed consent system assumes that everyone consents to be an organ donor, unless they actively ‘opt-out’ if they do not wish to donate their organs to people awaiting an organ transplant when they die. See Organ donation and PSC.


PBC - primary biliary cholangitis (previously called primary biliary cirrhosis). See also 'Differences between PSC and PBC'


PH - Portal hypertension.


Phenotype (of a disease) - the physical characteristics of a disease.


Portal hypertension - increased blood pressure in the large vein (portal vein) and all its branches that brings the blood from the intestine and spleen to the liver. See 'Portal hypertension'


Pouch - Reconnection of the small bowel to the anus following colectomy through creating pouch made from a portion of the small bowel; see also, colectomy, end ileostomy.


Prevalence - how many people have the condition (e.g. PSC) in a population (in a specific region or country) at a particular time. See 'Who gets PSC?'


Primary - occurring without any other obvious precipitating cause.


Primary biliary cholangitis (PBC) - an autoimmune liver disease NOT to be confused with PSC. See PBC and PSC.


Primary sclerosing cholangitis (PSC) - an autoimmune liver disease where the body’s immune system attacks its own bile duct cells. See 'What is PSC?'


Prognosis - the likely or expected development of a particular complication of a disease. See 'What will happen to me?'


Prognostic tool or scoring system - a method for predicting disease progression. It might be a specific test such as a blood test, or a combination of tests such as clinical factors, blood tests and imaging. See Prognostic tools.


Pruritus - another name for itch. See Itch and Tips on managing itch


PSC - primary sclerosing cholangitis.


PSC-IBD - A person who has PSC and IBD (almost always of the colon) has PSC-IBD. It is thought to be distinct from the IBD that affects people without PSC. See PSC-IBD


Recurrent PSC (rPSC) - PSC that returns after you have had a liver transplant. See Variants of PSC.


Roux-en-Y loop - in liver transplantation and biliary surgery, this refers to the way a loop of small bowel is created to join to the bile duct, usually of the donor liver. It involves surgery to divide and re- join the bowel together in addition to a join between the small bowel and the bile ducts.  See 'Your liver transplant'.


rPSC - recurrent PSC.


RUQ - right upper quadrant, meaning the upper right part of your tummy. See also URQ. See 'Pain'.


Sclerosing - hardening or scarring.


Serum liver tests - these are blood tests that provide an assessment of the liver and/or its function.


Small duct PSC - a variant of PSC that affects the small bile ducts only (i.e. those ducts not visible on an MRCP or ERCP). See 'Variants of PSC'.


Steatorrhoea - fatty stools which are pale, floating, bulky stools often difficult to flush. See 'PSC: Eating for health'.


Stent - in PSC, a stent usually refers to a small tube inserted into the bile duct to help keep it open. See 'ERCP'.


Stratify - to arrange or classify. Usually in PSC, it means to group similar patients according to the presence or absence of certain characteristics.


Surrogate biomarker - a measurement or test that is used as a substitute to show how a patient feels, functions, or survives and is expected to predict the effect of the drug or intervention being evaluated over shorter time period than waiting for the expected outcome to occur. See Surrogate biomarkers in PSC.


Strictures - the parts of the bile duct that are narrowed or scarred are called strictures. See 'Overview of PSC' and 'ERCP'.


TBS - Transplant Benefit Score. See 'National Liver Offering Scheme'


TIPS - transjugular intrahepatic portosystemic shunt. See 'Portal hypertension'.


Transjugular intrahepatic portosystemic shunt (TIPS) - a procedure to place a stent to keep the vein which brings blood from the liver to the heart open. See 'Portal hypertension'.


Transplant Benefit Score (TBS) - a score developed from characteristics of the person waiting for a transplant and the available donor liver to help decide who will get the greatest benefit from a donor liver and hence should be next in line to be offered that donor liver. See 'National Liver Offering Scheme'.


Type I error - also called a false positive error and it happens when a test is checking a single condition, and wrongly gives a positive decision, that is, says it is there when it is not.


Type II error - also called a false negative error and it happens when a test is checking a single condition and wrongly gives a negative decision, that is, it says it is not there when it is.


UC - ulcerative colitis.


UDCA - Ursodeoxycholic acid, or Urso. See 'UDCA'.


UKELD (United Kingdom Model for End-Stage Liver Disease) - a scoring system that provides a measure of how severe liver disease is, and the likelihood that a liver transplant is needed.


UK-PSC - a research group based in the UK made up of leading PSC researchers and specialists and PSC Support. See UK-PSC.


Upper Right Quadrant (URQ) - the top quarter of your tummy on the right-hand side. See 'Pain'


URQ - upper right quadrant. Also see RUQ. See 'Pain'


Urso - Ursodeoxycholic acid, or UDCA. See 'Is Urso safe and should I take it?'


US - ultrasound scan.


Validated - a research term that means something has been checked and proved/demonstrated to be accurate.


Variant Syndrome (VS) - used in UK liver transplantation to allow listing of patients who have liver disease where the UKELD and Transplant Benefit Score underestimate the need for liver transplantation. See National Liver Offering Scheme.


VS - Variant Syndrome. See National Liver Offering Scheme.

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