Approach to Abnormal LFTs By William E Stevens

Approach to Abnormal LFT’s By William E. Stevens, MD

Approach to Abnormal LFT’s • The biochemical LFT’s AST, ALK PHOS, BILI GGT, 5’NT, LDH ALB, P. T. • Abnormal LFT syndromes Severe vs. mild elevations Acute vs. chronic elevations Hepatitic vs. cholestatic pattern

The Aminotransferases: Aspartate aminotransferase (AST) Alanine aminotransferase (ALT) • Participate in gluconeogenesis; catalyzing transfer of amino groups to a~ketoglutarate • AST found in liver, heart and skeletal muscle, brain, kidney, pancreas, lungs, WBC’s, and RBC’s • ALT found primarily in liver • Elevations occur due to hepatocyte membrane damage • Almost all hepatobiliary diseases to some degree cause elevation • The higher the AST: ALT ratio, the more specific for ETOH related liver disease • AST: ALT >2: 1 is 90% specific for ETOH injury • AST: ALT >3: 1 is 97% specific for ETOH injury

Alkaline Phosphatase • Ubiquitous isoenzyme family found in liver, bone, placenta, kidney intestine, WBC’s • Slight elevations can occur normally in blood type O and B, after fatty meals, and increase with age • Isolated mild transient elevations are common, resolve spontaneously, are associated with no pathology • Abnormally low levels occur in hypothyroidism, pernicious anemia, zinc deficiency, Wilson’s disease • High elevations imply cholestasis due to intrahepatic, extrahepatic or infiltrative processes • Elevations occur due to enzyme induction and synthesis, levels may be normal with acute biliary obstruction

Gamma Glutamyl Transpeptidase (GGT) • Found in liver, biliary epithelium, spleen, pancreas, heart, lung, brain. Not found in bone • Primarily useful in confirming hepatic origin of an elevated alkaline phosphatase • Induced by ETOH, anticonvulsants, coumadin, etc • Most sensitive indicator for hepatobiliary disease • Very nonspecific; not very useful

5’ Nucleotidase (5 NT) • Found in liver, biliary epithelium, intestine, brain, heart, pancreas • Very specific for hepatobiliary disease • Levels correlate closely with alkaline phosphatase • Useful in confirming hepatic origin for elevated alkaline phosphatase

Lactate Dehydrogenase (LDH) • Widespread, ubiquitous isoenzyme • Elevations are due to cellular necrosis • Massive elevations are suggestive for ischemic necrosis • Limited diagnostic utility

Albumin • Liver synthesizes 10 gm/d • Serum half life is 20 days • Synthetic ability and serum levels decrease with progressive liver disease • Levels vary depending on nutritional status, volume status, vascular integrity, catabolism, urine and stool losses • Low levels are not specific for liver disease

Pro Time (PT) • Liver synthesizes Factors I, II, VII, IX, X, and degrades FDP’s • Elevations of PT are not specific for liver disease • Elevations that are due to liver disease are good indicators for severity of liver disease

Bilirubin • Derived from catabolism of hemoglobin • Two forms: water soluble--conjugated--direct water insoluble--unconjugated--indirect • Direct bilirubin increases due to defects in hepatic bilirubin excretion: biliary obstruction or hepatocellular disease • Indirect bilirubin increases due to increased hemoglobin breakdown or defects in hepatic uptake or conjugation

Evaluation of Abnormal LFT’s • Do a history: some liver diseases are more common in certain ages and genders Age <40: Autoimmune, Wilson's Dis >40: NASH, Hemochromatosis, Biliary obstruction Sex male: Hemochromatosis female: Autoimmune, PBC

Evaluation of Abnormal LFT’s Do a history • How long have they been abnormal? • How much Alcohol? • Any risk factors for viral hepatitis: IVDA, blood transfusion, tattoos, intranasal cocaine, multiple sex partners, multiple body piercing • Autoimmune symptoms: rashes, arthralgias, myalgias, thyroid problems, Sjogrens symptoms • Weight changes, anorexia • Cholestatic symptoms: RUQ pain, fever, chills, pruritus, jaundice, dark urine, light colored stools • Review medications, herbs, OTC medications

Evaluation of Abnormal LFT’s Do a physical exam • • Spider angiomas Enlarged liver and spleen Abdominal tenderness Findings of cirrhosis: ascites, edema, encephalopathy, palmer erythema, gynecomastia, testicular atrophy, caput medusa • Cardiac exam, heart murmurs, JVD

Abnormal LFT Syndromes • Isolated elevation of Bilirubin • Elevations of Alkaline Phosphatase and Bilirubin: Cholestasis • Massive elevations of AST / ALT • Mild chronic elevations of AST / ALT

Approach to an Isolated Elevation of Bilirubin • Elevations occur from – Bilirubin overproduction – Impaired bilirubin uptake, conjugation, or excretion – First fractionate bilirubin: conjugated vs. unconjugated • Unconjugated hyperbilirubinemia: – Increased bilirubin production: • hemolysis, hematoma, dyserythropoiesis (check haptoglobin) – Impaired bilirubin conjugation: • Gilbert’s Syndrome: 3 -7% population, increased in white males, Bili <6 • Chronic liver diseases, advanced cirrhosis, Wilson’s Disease, estrogens • Crigler-Najjar syndrome types I and II, extremely rare – Impaired hepatic bilirubin uptake: • rifampin, probenicid, CHF, etc. • Conjugated hyperbilirubinemia: – Dubin-Johnson Syndrome: abnormal excretion of bilirubin into bile ducts – Rotor Syndrome: defective intrahepatic storage of bilirubin • Both very rare; asymptomatic jaundice in 2 nd decade of life

Approach to Cholestasis Elevations of Alkaline Phosphatase and Bilirubin • • • History: abdominal pain, fever, pruritis, jaundice, medications, ? IBD If isolated Alk Phos elevation; confirm liver as source with 5’NT or GGT or Alk Phos isoenzymes Ultrasound – If US is abnormal • Biliary obstruction: CBD stones, strictures or biliary and pancreatic malignancies • Hepatic malignancy – If US normal • • • Consider medications: steroids, erythromycins, chlorpromazine, etc. TPN, sepsis, post-operative cholestasis, “intrahepatic cholestasis of acute illness” PBC, PSC, Vanishing bile duct syndrome Infiltrative diseases, steatosis/NASH, sarcoid, granulomatous liver disease If Alk Phos is <1. 5 x abnormal and US is normal, and patient is asymptomatic, then serial follow up is reasonable Otherwise, consider MRCP then Liver Biopsy or ERCP

Primary Biliary Cirrhosis • • Median age 50, Female: Male 9: 1 presents with fatigue, pruritis hepatospleenomegaly AMA+ 95% Liver biopsy: ductopenia with inflamed damaged intrahepatic bile ducts, granulomas, biliary cirrhosis • Treatment: manage osteoporosis, osteomalacia, fat soluble vitamin deficiency, pruritus, cholesterol, steatorrhea • Ursodeoxycholic acid

Approach to Massive AST/ALT Elevations (>2000) • Limited differential diagnosis: • Drugs/Toxins: Tylenol, ETOH + Tylenol, other idiosyncratic reactions, mushrooms, herbs • Viral Hepatitis: A, B, C, D, E, HSV, Giant Cell virus, others • Ischemic Hepatitis: hypotension, CHF, arrhythmias, cocaine • CBD Stone • Autoimmune Hepatitis

Approach to Mildly Abnormal AST /ALT: 100 Consecutive Blood Donors with Mildly Abnormal ALT • Findings after H & P, serologies and ultrasound: • 48% ETOH • 22% Fatty Liver • 17% HCV • 4% other • 9% no identifiable explanation

Mildly Abnormal LFT’s Liver Biopsy Findings • 81 with chronically abnormal LFT’s and negative H & P and serologic evaluation – 84% Hepatic steatosis or NASH – 6% advanced fibrosis or cirrhosis – 8% normal • Summary – Most etiologies are identified by history, physical, basic serologies or ultrasound – Most cases still with diagnostic uncertainty are due to ETOH or Hepatic Steatosis / NASH – Liver Biopsy aides management in ~18% – Complication rate of liver biopsy ~1 -3% • Severe complications occur in 0. 1%

Causes of Mild Chronic Elevation of AST/ALT • Hepatic causes: • Nonhepatic causes: ETOH Medications, herbs Hepatitis C and B Steatosis and NASH Autoimmune hepatitis Hemochromatosis Wilson’s disease Alpha-1 -antitrypsin deficiency Celiac sprue CHF Thyroid and Adrenal disease Muscle diseases and strenuous exercise

Laboratory Tests in Asymptomatic patients with Mild Chronically Elevated AST/ALT • Primary tests: Repeat LFT’s HCV antibody HBV Surface antigen HBV Surface antibody HBV Core antibody Transferrin saturation, ferritin • Secondary tests: ANA, ASMA Ceruloplasmin (age<40) Alpha-1 -antitrypsin phenotype Ultrasound

Alcohol Related Liver Disease • • 14 million alcoholics in U. S. 2 million in U. S. with alcohol related liver disease >14, 000 liver related deaths per year due to alcohol prevalence is higher in men; women are more susceptible to liver injury • risk of liver injury increases with consumption of over 30 gm/d ETOH; only 10% who consume over 80 gm/d get liver disease • AST: ALT >2 -3: 1 GGT >2 x elevated • AST and ALT usually less than 300

Hepatic Steatosis and NASH • Most common cause of unexplained abnormal LFT’s • 25% ultrasounds in U. S. show “fatty liver” • Likelihood for advanced disease increases if: age >40, Type 2 Diabetes Mellitus, Obesity, Hyperlipidemia • May have RUQ pain, hepatospleenomegaly • AST=ALT, levels usually <200 • Consider liver biopsy for diagnosis and staging. Liver biopsy looks like alcoholic hepatitis • Treatment: weight loss, improve DM and lipid control, stop ETOH, ? ursodeoxycholic acid, ? metformin, ? Vit E

Viral Hepatitis C and B • Hepatitis C 3 -4 million in U. S 90% have “risk factors”, 30% have normal LFT’s HCV antibody is 97% sensitive HCV RNA PCR is confirmatory test Treatment: PEG interferon + Ribavirin • Hepatitis B 1 million in U. S. Increased in homosexuals, African and Asian immigrants, HCV risk factors HBV S Ab+, HBV Core Ab+ = immunity, prior disease HBV S Ag+ = presence of disease HBV E Ag+ or HBV DNA + = active viral replication, infective Treatment: PEG interferon, or Lamivudine, Adefovir, Entecavir

Hemochromatosis • Primary genetic hemochromatosis; 1/200 (0. 5%) Caucasians • Secondary hemochromatosis due to chronic hemolysis • May have RUQ pain, arthritis, impotence, diabetes, hepatomegaly, skin pigmentation • Transferrin Saturation >45%, elevated Ferritin • HFE testing: C 282 y, H 63 d mutations account for 90%; 10% Caucasians are heterozygotes • Liver Biopsy if Age>40, abnormal LFT’s, Ferritin > 1000, uncertain diagnosis • Treatment: Phlebotomy every 1 -2 weeks until iron depleted; then 2 -6 times per year

Medication Induced Abnormal LFT’s • Almost any medication cause abnormal LFT’s • Ask when medications were started; OTC medications, herbal preparations • Stop probable offending medications • Risk/Benefit analysis if medication must be continued. Liver Biopsy may be helpful.

Medications that Cause Elevated LFT’s • Antibiotics: penicillin's, mycin's, floxicin’s, nitrofurantoin, keto and fluconazole, INH • Antiseizure: dilantin, tegretol, valproic acid • Statins and Niacin • NSAID’s: diclofenac • Sulfonylureas: glypizide • Vitamin A • Herbs: germander, chaparral, mahuang, gentian • Drugs: ecstasy, cocaine, PCP, glues, solvents

Autoimmune Hepatitis • 150, 000 in U. S. ; female: male, 4 -6: 1 • 40% have other autoimmune diseases: thyroid, RA, UC, Sjogrens, • ANA, ASMA + 70% • Elevated Ig G • Treatment: prednisone + imuran

Wilson’s Disease • Wilson’s disease gene facilitates biliary copper excretion. • Age of onset 6 -40 • Various presentations: Hepatic fulminant liver failure chronic active hepatitis Neurologic movement disorder rigid dystonia Psychiatric neuroses, depression • Diagnosis: low ceruloplasmin, high 24 hour urine copper, liver biopsy, Kayser-Fleischer rings present in 95% • Treatment: Penicillamine, Trien, Zinc

Alpha-1 -Antitrypsin Deficiency • Protease inhibitor; inhibits neutrophil elastase; modulating inflammatory cascades • 1/1500 Caucasians • Abnormal phenotype causes retention of A-1 -AT in hepatocytes • Normal: MM; most abnormal: ZZ other variants: MZ, MS, SZ • Neonatal or childhood cholestatic hepatitis • In adults: emphysema and cirrhosis

Asymptomatic Patients with Abnormal ALT and Negative Serologic Evaluations • 1124 patients with chronically elevated ALT • 81 patients had NEGATIVE serologic evaluations • All had Liver Biopsy. Findings: 41 fatty liver 26 NASH 4 fibrosis with fatty liver 2 cirrhosis with fatty liver 8 normal

Mild Elevations of LFT’s Epidemiology • 19, 877 Air Force recruits • 99 (0. 5%) had ALT >55 • Only 12 (12%) had a cause identified – HBV, HCV, Autoimmune, Gallstones – 88% no identifiable cause identified

Hepatobiliary Syndromes • • Hepatitic pattern: elevated AST, ALT Cholestatic pattern: elevated Alk Phos, Bili Acute versus chronic elevations Massive versus mild elevations