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Hepatitis Serology
Gastroenterology
Question | Answer |
---|---|
Hepatitis labs | AST/ALT very high (20x nml) early; WBC nml to low; TBil follows AST/ALT; alkphos parallels bili |
ALT/AST in infxs hep: | Usu ALT:AST > 1.0 |
ALT/AST in EtOH hepatitis: | AST:ALT >1.0 |
Hepatitis: urine labs: | mild proteinuria; bilirubinuria often precedes jaundice; may be incidental indicator of liver injury |
Hep: liver not primary target in: | EBV, CMV, other (HSV, yellow fever, mumps, rubella) |
Hepatitis: liver is primary target in: | hepatitis viruses |
Hepatitis serum tests | Immuno detection (EIA, RIA, RIBA, PCR); bx not for dx but useful for staging Hep C |
Most common cause of chronic hep | viral |
Most common PREVENTABLE infxs dz | Hep A |
Dx of acute infxs hep is by presence of: | IgM anti-HAV: indicates previous exposure to HAV, noninfectivity & immunity; past exposure common in US (30%); Total anti-HAV to screen ppl who may need vax |
Hep B: more likely to become chronic if: | young at age of infxn (or immunocompromised); 95% of pts clear the virus & develop Abs; chronic Hep B increases risk of cirrhosis & HCC |
First evidence of hep B infxn (persists throughout clinical illness): | HBsAg |
Appears after clearance of HBsAg or successful vax vs Hep B | Anti-HBs; |
Detection of Anti-HBs indicates: | recovery from HBV infxn, noninfectivity & immunity |
Anti-HBc IgM | Appears soon after HBsAg, before anti-HBs; presence w/ acute hep sx = acute Hep B; Persists 3-6 mos |
Anti-HBc IgG | Appears with Anti-HBc IgM, but persists |
HBcAg: | does not appear in serum |
HBeAg: | Secretory form of HBcAg; found only in HBsAg positive serum soon after its detection; Presence indicates viral replication & infectivity |
Anti-HBe: Presence (after clearance of HBeAg) indicates: | less viral replication & infectivity |
Hep B immunity (types) | Recovered from infxn: Anti-HBs pos, Anti-HBc IgG pos; vax: Anti-HBs pos, Anti-HBc IgG NEG |
HBV DNA | Parallels HBeAg, but is more sensitive/ precise marker of viral replication & infectivity; Low levels may persist in serum & liver after recovery from acute Hep B; HBV DNA in serum is bound to IgG & rarely infectious |
Hep C characteristics | high rate of chronic infxn (85%); cause of cryoglobulinemia; Dx: anti-HCV by ELISA, may need confirm w/HCV RNA & anti-HCV RIBA; Ab levels rise slowly |
Only test for Hep D if: | if pt has confirmed & unexplained worsening of Hep B |
Hep D characteristics | Requires HBsAg; worsens Hep B prognosis, inc risk of liver ca; Dx anti-HDV or HDV RNA in serum |
Hep E characteristics | Usu benign & self-limited; rare; 10-20% mortality in PG; Dx anti-HEV |
DUMC acute hep panel | HCV Ab; HBc IgM; HBs Ag; HAV IgM Ab |
"window period" = | serologic gap between the time HBSAg clears and antibody (HBS-Ag) becomes detectable |
IgG Ab in presence of HBSAg indicates: | chronic infection (in the absence of HBSAg = recovery) |
Fibrosure = | 6 biochemical marker test for HCV; correlates well with liver bx |