LFTs

Liver Function Tests

Dr. Isra Omar

Leenah Turjoman ♥

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Functions of the liver

Proplem in liver will lead to dearrangement of these functions

• Synthesis of proteins → albumin,…
• Metabolism od xenobiotics → food, toxins
• Bile formation

Liver cirrhosis:

• ascites → due to protein
• Jaundice

Synthesis of

• Clotting factors → 10, 4, 7, 2

Synthesis of

• Thrombopoietin → imp in synthesis of platelets → so liver disease lead to → petechia → Hemmorrhage (Tendency of bleeding)
• Vit D activation → 25 hydroxylation occur in liver (1 hydroxylation occur in kidney)

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Liver Enzymes

• ALT
• AST
• ALT
• AST Inside hepatocytes → damage to hepatocytes → what’s inside it will go out to blood
• ALP
• GGT From the biliary system

*inlury to hepatocytes → ALT, AST will be high in blood. Also ALP and GGT will be high because hepatocytes and biliary system are close to each other. and vice versa

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A) Hepatocellular injury

if labs came back like this, do:

• Viral screen
• Globulin albumin ratio
• ASMA
• ANA
• Paracetamol level
• (Alcohol history)
• Doppler US

Can be hundreds of first, but rising, so history is imp.

• ALT and AST (thousands) will be very high ALP and GGT will be high but not to the same level

The differential viral hepatitis

1. Viruses (hepatitis A, B, C, D, E and other hepatotropic viruses e.g., [CMV, EBV, VZV] → viruses that affect immunosuppressants due to kidney transplant → These viruses can not cause liver damage in immunocompetent people

2. Autoimmune hepatitis (ANA, ASMA, high immunoglobulin) pt will come with high ALT, AST but high proteins also which is non logical in case of liver injury

Usually remote May have history of other autoimmune diseases eg. RA

Usually remote May have history of other autoimmune diseases eg. RA

is young female, suicide attempt, changed liver functions, high bleeding time, ALT and AST high, but ALT is higher. ALT and GGT will also be high

3. Drugs (paracetamol) order toxicology screen (proteins) metabolized by conjugation by acetylation (glucosurination and sulfation) and excreted if taken in high dose, glucosurination and sulfation are saturates, so liver makes paracetamol go through phase 1 reaction, forming NAPOI, a toxic metabolite and this NAPOI goes through phase 2

→ can be hundreds of first, but rising, so history is imp.

→ Viruses that affect immunosuppressants due to kidney transplant → These viruses can not cause liver damage in immunocompetent people

→ Uricumcults viral hepatitis

→ Malaria, tuberculosis, and other hepatitis → Can be positive

→ Specific for autoimmune hepatitis

→ Malaria, tuberculosis, and other hepatitis → Can be positive

→ Malaria, tuberculosis, and other hepatitis → Malaria, tuberculosis, and other hepatitis

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+radiode for paracetamol toxicity: N-acetyl cystine Sulfa containing amino acids so will generate glutathione (giving the treatment of glutathione is better than glutathione alone)

reaction, will bind to glutathione and excreted. If no more glutathione, the free NAPOI will cause injury to hepatocytes, leading to fulminant hepatic failure or acute liver failure

1. Alcohol (AST will be higher than the ALT) and GGT will be high with alcohol which is characteristic for alcohol induced hepatic injury

2. Ischemic injury to the liver → supplied by hepatic artery which is a branch of celiac trunk → drained by hepatic veins which drains into IVC

(no blood to liver will lead to liver failure)

e.g. female with (and phospholipid syndrome) or libido reticularis bilking (hele thrombus embolic phenomena) bilemms thrombosis

• Female, 70 year old, KC of atrial fibrillation, taking digoxin, presented with Ruo Pain → its due to ischemic injury to liver

Arterial blockage or reduced blood supply (shock liver, thrombus occluding hepatic artery) → eg. due to Atrial fibrillation

Hepatic vein (Budd Chiari syndrome) → occlusion of hepatic veins → liver will be congested

• IVC (right side heart failure) due to congestion → lead to congestion of IVC

• Ischemic injury to the liver when suspected is investigated via doppler US

*if patient is alcoholic, could be non alcoholic steatohepatitis → ALT higher or alcohol induced hepatitis → AST higher

*if ALT and AST high (but not in thousands), and AST is higher than ALT, Tricholesterol: alcohol induced hepatitis

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ALT and AST high but not as much as thousands think about the following causes

meaning there is liver damage but not fulminant liver damage

1. Nonalcoholic steatohepatitis (I suspect it when the patient has DM, obesity, HTN, Hyperlipidemia and metabolic syndrome) ALT is higher than the AST more than two times. US will show fatty liver → inflammation will occur → non alcoholic Steatohepatitis Patient drinks alcohol

2. Congenital disorders (Wilson syndrome, hemochromatosis)

• Wilson syndrome there is abnormality in copper excretion. Suspected when the patient is young, we treat it by copper chelators 60 its accumulated high copper → low ceruloplasmin fatty → ceruloplasmin Coffee, coffee

• Hemochromatosis occur due to iron deposition in tissues and treated by deferoxamine There is excess absorption of iron have high hemoglobin deposited in:

• Pituitary gland

• (causing hypogonadism, hypofiltration)

• Skin → bronzing of skin

• Heart → cardiomyophytes → sobs

• Liver → keratitis followed by cirrhosis deposited in:

• Basal ganglia

• (causing movement disorders of cortex)

• Eye → lesser flesher ring

• Liver → some keratitis followed by cirrhosis

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Pancreas → bronze® diabetes

B) Biliary problems

*First thing to do: US → will show if problem is extra hepatic or intra hepatic → Then follow that with: ERCP, MRCP, CT scan → To know the cause → order PANCA and HIV serology → will show tumors

• high ALP, GGT, Direct bilirubin, AST and ALT
• GGT is more specific than ALP because ALP can be elevated from other sources like placenta, bone when there is high bone turn over e.g., in Paget’s disease and kidney in patients with acute kidney injury. But in general, we depend on ALP → osteoporosis
• We calculate the R value in order to differentiate between hepatic and biliary injury
• R=ALT/upper limit of the normal ÷ ALP/upper limit of the normal $R=\frac{ALT}{ALP}$
• ≥5 hepatic injuries
• ≤2 biliary injury → next step: US
• 2 – 5 represent mixed picture

*if ALP is high → R value will be low

*17 year old female with N/V and high ALP (but other liver enzymes are normal), The cause is: Pregnancy (ALP inc with estrogen and it also comes from placenta)

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Causes of biliary injury

• a) extrahepatic most common surgery: female, >40,000

1. Stone
2. Cholangiocarcinoma
3. Tumor of the head of the pancreas
4. Primary sclerosing cholangitis (IBD) p ANCA will be positive
5. Secondary sclerosing cholangitis (HIV) Patient travel a lot, have multiple sexual relation ship, most likely have HIV → get 2y Sclerosing cholangitis

• For these patients will have duct dilatation in US. In order to find the cause, we will do ERCP, MRCP, CT and p ANCA

e.g. from Tailand → eat fish, there is worms in biliary system → patient will have loss of weight, deeply Journisced, old age → close to biliary system → human, smother, old age Patient will be KC of ulcerative colitis → will get 1y Sclerosing cholangitis as extra intestinal manifestations HIV → hepatotopic virus → high ALT and AST → 2y Sclerosing cholangitis → high ALP and GGT

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b) Intrahepatic: no duct dilatation on US. Causes includes the following

1. Primary biliary cirrhosis (female over 40 with splenomegaly and positive AMA) deep Jaundice
2. Metastatic tumor from lung, bronchus and pancreas
3. Granulomatous disease (sarcoidosis, TB) and amyloidosis

• Drugs e.g., estrogen and erythromycin

(That cause dearranged liver function)

↓ Tylical case:

• Female taking contraceptives or hormone replacement therapy
• Transgender male taking estrogen

↓ MOA: Protein Synthesis inhibitor

• First effect is dearranged over function e.g. cholestatic picture (high ALP and GGT)
• Causes prolongation of QT interval which led to Torsodes de Paintes

(brunchogenic carcinoma) ↓ MCHC: mictotestis is to biliary system leading to obstruction intrahepatic ↓ Treatment: Carcosteroid ↓ Treatment:

• Rifampicin
• Isoniazide
• Streptomycin
• Pyrazinamide
• Ethambutol

→ Proteins deposited in organs, can lead to loss of function of that organ → Causes:

• Familial mediterranean fever
• RA
• Substrative lung disease
• Low bronchitis

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GOOD LUCK