Chapter 5 Liver function tests Liver function tests include

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Chapter 5 Liver function tests

• Liver function tests include the tests of protein
  metabolism, the tests of bilirubin metabolism,
  the tests of dye intake and excretion, the tests
  of serum enzymes and the tests of viral
  hepatitis.
• In general , the tests currently available can
  be divided into two categories the tests of
  hepatic function or capacity and the screen-ing
  tests that suggest the presence and /or type of
  liver disease. Specific diagnostic tests such as
  serologic tests for hepatitis infection are also
  covered in this chapter.

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Tests of protein metabolism

• Serum total protein (TP),albumin (A) and globulin
  (G)
• The normal range of TP, A and G is 60-80g/L,
  40-55g/L and 20-30 g/L . The normal ratio of A to
  G (A/G) is 1.5-2.5 1
• Increased G and decreased A (reversed A/G) can be
  seen in chronic hepatitis, cirrhosis, hepatic
  neoplasm .

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• Serum protein eletrophoresis
• A 0.61-0.71 , a1 0.03-0.04 , a2 0.06-0.1 , B
  0.07-0.11 , r 0.09-0.18
• cirrhosis and hepatic neoplasms A , a1, a2, B
  decrease , r increase
• hepatitis in acute hepatitis normal level,
• in chronic hepatitis A
  decrease, r increase

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• hepatic neoplasm markers

alpha fetoprotein (AFP) lt 25ug/ L , gt 500 ug /L
primary hepatocellular carcinoma
carcinoembryonic antigen (CEA) 0-5 ug /L ,
increased CEA liver metastatic carcinoma or
other carcinomas of the gastrointestinal system
abnormal prothrombin (APT) lt 20 ug/L,
increased APT primary hepatocellular carcinoma

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Tests of bilirubin metabolism

• serum total bilirubin(STB), serum direct
  bilirubin (SDB) and serum indirect bilirubin(SIB)
• STB 1.7-17.1 umol/L (normal), 17-34 umol/L
  (latent jaundice), hyperbilirubinemia
• SDB 0-6.8 umol/L (normal), SIB 1.7-10.2
  umol/L (normal), SDB/STB 20 (normal),
• urea bilirubin normal (-), when SDB gt 34
  umol/L ()
• urobilinogen normal (- )

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Clinical significance of tests in bilirubin
metabolism(umol/L) STB SDB
SIB SDB/STB URO UBI
normal 1.717.1.7 10.2 06.8
20 - - hemolysis lt85
mild significant lt20
- hepatitis 17200 medium medium
gt35 biliary
200500 significant mild gt60
- obstruction  
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Dye intake and excretion

• Indocyanine green retention rate (ICGR) 15
  mim lt 10
• chronic hapatitis 1520
• cirrhosis 35

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Serum enzyme tests

• aspartate ( AST, SGOT) and alanine ( ALT, SGPT)
  . The serum transaminase are sensitive tests of
  liver damage. And the height of the activity
  reflects the severity of hepatic necrosis.
• ALT lt 35U/L, AST lt40U/L
  
• elevated ALT,AST acute hepatitis (viral or
  toxic ), chronic hepatitis and cirrhosis,biliary
  obstruction

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• Alkaline phosphatase (ALP)
• Serum levels are elevated in association with
  cholestasis, partial or complete bile duct
  obstruction, bone regeneration, and also with
  neoplastic , infiltrative, and granulomatous
  liver disease. An isolated elevated ALP level may
  be the only clue to partial obstruction of the
  common bile duct.
• ALP 30-130 U/L ( 36-92 U/L)
• elevated ALP bile duct obstruction, primary
  hepatocellular carcinoma, hepatitis

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• r-glutamyl transferase (r-GT)
• 317U/L(M), 213 U/L(F)
• elevated r-GT hepatic neoplasm
• obstructive jaundice
• hepatitis

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Tests of viral hepatitis

• Viral hepatitis is caused by five main viruses
  hepatitis viruses A, B, C, D and E. In present,
  hepatitis A , hepatitis B and hepatitis C are
  more common. The ability to detect the presence
  of viral components in hepatitis B and C and
  antibodies to components of hepatitis A,B, C and
  D has enabled considerable progress to be made in
  the study of the epidemiology of viral hepatitis.
  These so-called viral markers can be diagnostic
  of the cause of acute viral hepatitis.

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serologic markers of viral hepatitis agent
markers definition
significance HAV anti-HAV antibody to
HAV IgM type
current or recent infection

or convalescence IgG
type current or
previous infection
, confers
immunity HBV HBsAG HBV surface
antigen positive in acute

or chronic infection HBeAG
e antigen, a component transiently positive
of the HBV core
in acute Hepitis B ,may

reflects presence of viral

replication and infectivity
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anti-HBe antibody to e antigen
transiently positive in convalescence,

may be persistently present in chronic

cases, reflects low infectivity
anti-HBc antibody to core antigen
IgG type
positive in all acute and chronic cases,

reliable marker of infection ,past or

current IgM
type reflects active viral
replication ,
not protective
anti-HBs antibody to surface antigen
positive in late convalescence,

confers immunity, after injection of

Hepitis B vaccine HCV anti-HCV antibody to
HCV positive after clinical onset(15 week),

not protective, persists in chronic

infection  
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• Automatic biochemistry analyzer
• Using the analyzer, we can detect 14 items of
  liver and renal function tests easily.
• ALT, AST, CHO, ALP, GGT, TBIL, DBIL, TP, ALB,
  GLB and BUN, CRE, GLU, UA

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Case analysis

• History and physical examination This
  48-year-old man had complained of abdominal pain
  and intermittent fever for 3 months. The pain was
  usually felt in the right upper quadrant. His
  appetite was not good and lost his body weight
  apparently. He once suffered from hepatitis ten
  years ago. Physical examination revealed the
  patient who appeared chronically ill with icteric
  selera. The liver was enlarged to 2 cm below the
  costal margin with tenderness, and the spleen was
  enlarged to 3 cm below costal margin .

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• Laboratory data Hb 90g /L, WBC 8.0109/L, PC
  90109/L, ALT 120U/L, AST 200U/L,ALP 255U/L, TP
  55g/L, A 25g/L, Y 40, TBI 55umol/L, DBI
  38umol/L, URO (), UBI (),AFP 600ug/L, HBsAg
  (), HBeAg (), anti-HBc IgM ()
• Question
• What is your diagnosis for this patient?
• Which kind of jaundice this patient has?
• How to evaluate this patients liver function?
• What is etiological classification for his
  hepatitis?