Page 447 - Concise Pathology for Exam Preparation ( PDFDrive )

432 SECTION II Diseases of Organ Systems

Salient features of different types of hepatitis have been given in Table 15.3.

TABLE 15.3. Comparative features of different types of hepatitis
Features Hepatitis A Hepatitis B Hepatitis C Hepatitis D Hepatitis E Hepatitis G
Agent Icosahedral Enveloped Enveloped Enveloped Unenveloped ssRNA
capsid, dsDNA ssRNA ssRNA ssRNA
ssRNA
Incubation 2–6 weeks 4–26 weeks 2–26 weeks 4–7 weeks 2–8 weeks Unknown
period
Transmission Feco-oral Parenteral, Parenteral, Parenteral, Waterborne Parenteral
close close con- close
contact tact contact
Carrier state None Present Present Present Present
Chronic hep- None 5–10% of .50% ,5% coin- None None
atitis acute fection,
infections 80% super
infection
Hepatocellu- No Yes Yes No increase Unknown None
lar carci- above
noma HBV
Diagnosis Detection of Detection of PCR for Detection of PCR for HEV Not a primary
serum HBsAg or HCV IgM and RNA; De- hepatotropic
IgM anti- antibody RNA; IgG anti- tection of virus; repli-
bodies to HBcAg third- bodies; serum IgM cates in the
generation HDV RNA and IgG bone marrow
ELISA for in serum antibodies and spleen
antibody and HDAg
detection in liver

Q. Define fulminant hepatic failure and write briefly on its causes
and clinicopathological features.
Ans. Fulminant hepatic failure is defined as sudden loss of hepatic function, occurring within
4 weeks of onset of the precipitating illness, in the absence of any evidence of pre-existing liver
disease. More protracted course over months is labelled submassive or subacute hepatic necrosis.

Aetiology
• Acute viral hepatitis (A, B and E)
• Hepatotoxic drugs (isoniazid and phenytoin)
• Poisoning, eg, Amanita phalloides
• Shock
• Wilson disease

Pathology
• Shrinkage of liver with extensive parenchymal necrosis
• Complete destruction of hepatocytic lobules leaving only preserved portal tracts
• Collapse of reticulin framework
• Survival beyond day’s influx of inflammatory cells; survival more than a week regenera-
tion of surviving hepatocytes seen

Clinical Features
• Weakness, nausea, vomiting, right hypochondrial pain and jaundice
• Features of hepatic encephalopathy and cerebral oedema
• Renal failure

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