CC Jan 2018 Abnormal Liver Chemistries

echoecho's version from 2018-01-14 15:31


Question Answer
In 2016, the American College of Gastroenterology (ACG) published a guideline to aid in the evaluation of abnormal liver chemistries (abnormalities of ALT, AST, alkaline phosphatase and bilirubin). Many of these abnormalities are mild and of no clinical significance, but why is it important to identify potentially serious conditions?So they can be addressed in a timely manner
Why should liver chemistries not be described as liver function tests?Because liver chemistries are markers of liver INURY
List the characteristics of AST?1) is a hepatic enzyme involved in the transfer of aspartame amino groups to ketoglutaric acid 2) AST is present in cardiac and skeletal muscles, kidneys, brain. 3) Isolated elevation of AST suggests cardiac or skeletal muscle pathology
List the characteristics of ALT?1) is a hepatic enzyme that facilitates the transfer of alanine-amino groups to ketoglutaric acid and like AST, is a marker of hepatocellualr injiury 2) primarily found in the liver and is considered to be more specific for liver injury than jAST
List the characteristics of alkaline phosphate?1) it catalyze the hydrolysis of phosphate esters in an alkaline environment 2) widespread in the body (bone, placenta, intestines, kidneys) 3) elevated in pregnancy and with increased bone turnover (especially in older women) 4) may be elevated due to obstruction of the biliary ducts 5) concomitant elevation of GGT suggests a hepatic source of elevated alkaline phosphatase
List the characteristics of bilirubin?1) results from the breakdown of red blood cells, and is tightly bound to albumin (called UNCONJUGATEd B ILIRUBIN) 2) conjugation of this form leads to CONJUGATED bilirubin that can be excreted in the urine and stool 3) in patients with elevated TOTAL bilirubin that is mostly in the unconjugated form, hepatic disease is unlikely 4) an elevated bilirubin due to conjugated form represents hepatic disease or biliary obstruction
Albumin is a plasma protein exclusively synthesized by the liver with a half-life of about____ weeks?3
Lower levels of albumin typically indicates what?1) malnutrition OR 2) impaired liver function that has been present for at least 3 weeks
Production of clotting factors II, VII, IX and X is vitamin ____ dependent?K
In the setting of cholestasis, is vit K absorbed? What is then the result?1) no 2) resulting in prolongation of PT and this can occur within 24 hours of the onset of severe liver disease
*** List the recommendations that were made by the ACG guidelines?1) truly normal levels of liver chemistries must be established. For alkaline phosphate and bilirubin, levels > 2 standard deviations above the mean constitute abnormal values. Reference labs have consistently established mean levels for alkaline phosphatase and bilirubin that can be reliably replicated. AST and ALT have proven to be more problematic due to the differences in the populations of healthy volunteers used to establish normal values. For example, elevated BMI ( > 25) is associated with a linear increase in ALT. The guidline recommends that the upper limit of normal for ALT should be 29-33 in men and 19-25 in women. The guidline authors do not define abnormal ALT or AST as multiple of upper limit of normal (3 times the normal limit of normal) as seen in previous guidelines 2) when the ALT to AST ratio is > 18, all cause mortality increase threefold 3) abnormal ALT and AST should be confirmed by repeat testing 4) when persistent elevations of AST or ALT are present, viral hepatitis should be considered. If fecal-oral exposure exists, testing for hep A should be obtained. Testin for hepatitis B should be considered for endemic areas (HBsAg prevalence in the community of > 2%), in men who have sex with men, individuals with a hx of IVD, patients on dialysis, HIV-infected individuals, pregnant women and household contacts or sexual or sexual contacts of individuals infected with hepatitis B. Testing for acute hepatitis B includes HBsAg and IM anti-HBc studies. For chronic hepatitis B, HebsAg is used. Hep C testing should be performed for all at-risk patients, including those with a hx of intranasal or IV drug abuse, tattoos, body piercings, blood transfusion or high-risk sexual behavior and those born between 1946 and 1965.
*** Regarding the recommendations that were made by the ACG guidelines, patients with what conditions have a higher incidence of NAFLD (nonalcoholic fatty liver disease) that is associated with mild elevations of ALT and AST?metabolism syndrome (obesity, DM, hyperlipidemia, and/or HTN)
*** Regarding the recommendations made by the ACG guidelines, is there a specific pattern of liver chemistry elevatation suggestive of NAFLD? What is a subset of NAFLD? What imaging study should be done to r/o NAFLD in patients with mild AST or ALT elevations and metabolic syndrome?1) no 2) subset of NAFLD is associated with inflammation, fibrosis and a higher potential for development of cirrhosis but is difficulty to identify 3) US liver
*** Regarding the recommendations made by the ACG guidelines, chronic alcohol consumption has been associated with elevations of AST and ALT, what is the classic pattern? What is significant amounts of alcohol consumption definition? Is the US indistinguishable from alcoholic liver disease from NAFLD? What should providers be counseling their patients about drinking?1) classic pattern is ALT which is 2-3 times higher than AST with higher ratios suggestive of alcoholic liver disease 2) Greater than 210 grams of alcohol per week (15 standard drinks for men), treated than 140 grams per weigh for women (10 standard drinks) 3) yes 4) reduce alcohol consumption
*** Regarding the recommendations made by the ACG guidelines regarding hereditary hemochromatosis?1) it is an inherited disease hat affects the liver usually in Northern European descent 2) if testing for viral hepatitis is normal, screen for hemochromatosis with transferrin saturation and serum ferritin 3) if transferrin saturation > 45% or the serum ferritin is elevated, testing should be done for the HFE gene mutation
*** Regarding the recommendations made by the ACG guidelines regarding mild elevations of AST and ALT in men < 55 years old? For those patients with persistent mild elevations, consider screening for what? In the presence of autoimmune disorders (SLE, RA, Sjogren disease, psoriatic arthritis), what tests should be done?1) consider r/o Wilson's disease with serum ceruloplasmin 2) for persistent mild elevations, consider alpha-1 antitrypsin disease with genetic testing 3) ANA, ASMA (anti-smooth muscle antibody and serum immunoglobulin levels to r/o autoimmune hepatitis
*** Regarding the recommendations made by the ACG guidelines regarding drugs that can cause elevation of AST and ALT, list the common drugs that do so? Comment on herbal supplementations that cause also increase AST and ALT? Can statins be used safely in chronic liver disease patients?1) acetaminophen, antibiotics, anti-epileptic drugs, HMG-CoA reductase inhibitors (statins), antituberculous drugs, anti-retro viral therapy, anti tumor necrosis factors, chemotherapeutic agents 2) herbal supplements as chaparral, ephedra, jib u huan, germander, green tea extract, shark cartilage 3) yes statins have been used safely in patients with chronic liver disease
*** Regarding the recommendations made by the ACG guidelines, when is liver biopsy considered?1) when serologic testing and imaging fail to confirm a diagnosis 2) when staging of a condition is needed or when multiple diagnoses are possible
*** SUMMARY = Elevated levels of what liver enzymes are indicators of hepatocellular damage and are not markers of liver function?ALT and AST
*** SUMMARY = Abnormalities in liver enzymes should be confirmed by _____ testing?repeat
*** SUMMARY = What conditions can cause elevations in liver enzymes?1) metabolic syndrome 2) chronic alcohol use 3) hepatitis and drug interactions
*** SUMMARY = The _____ of ALT and AST elevation can suggest the etiology?magnitude
*** SUMMARY = What imaging study is useful in evaluation of elevated liver tests?US liver
*** SUMMARY = US does not differentiate between what/between alcoholic liver damage, nonalcoholic fatty liver disease (NAFLD) and nonalcoholic stem hepatitis (NASH)
*** SUMMARY = What type of testing may be required for definitive diagnosis?biopsy