Viral Hepatitis C

Question 1

Define

Answer 1

hepatitis caused by infection with hepatitis C virus (HCV), often following a chronic course (in 80% of cases)

Question 2

Causes

Answer 2

• HCV is a small, enveloped, single-stranded RNA virus
• RNA viruses have poor fidelity of replication and mutation rates are high
• So, there are lots of HCV genotypes (which can co-exist in a single patient)

Transmission: PARENTERAL

• Sexual transmission
• Vertical transmission

At risk patients:

• Recipients of blood and blood products
• IV drug users
• Non-sterile acupuncture
• Tattooing
• Haemodialysis
• Health care workers

Pathology/Pathogenesis of HCV

• The virus is not thought to be directly hepatotoxic
• It is the humoral and cell-mediated responses to the viral infection that leads to hepatic inflammation and necrosis

Liver biopsy shows:

• Chronic hepatitis
• Lymphoid follicles in portal tracts
• Fatty change
• Cirrhosis may be present

Question 3

Epidemiology

Answer 3

COMMON

Different genotypes of HCV have different geographical prevalence

Question 4

Symptoms

Answer 4

90% of acute infections are ASYMPTOMATIC

10% become jaundiced with mild flu-like illness

May be diagnosed after incidental abnormal LFT

Question 5

Sings

Answer 5

May be NO SIGNS

There may be signs of chronic liver disease (if long-standing HCV infection)

Extra-hepatic manifestations (rare) include:

• Skin rash
• Renal dysfunction (due to glomerulonephritis)

Question 6

Investigations

Answer 6

Bloods

HCV Serology

• Anti-HCV antibodies - IgM (acute) or IgG (past exposure or chronic)

Reverse-transcriptase PCR

• Allows detection and genotyping of HCV

LFT

• Acute infection: High ALT, AST and bilirubin
• Chronic infection: 2-8 x elevation of AST + ALT (often fluctuates over time)

Liver Biopsy

• Assess the degree of inflammation and liver damage
• NOTE: transaminase (AST and ALT) levels bear little correlation to histological changes
• Useful for diagnosing cirrhosis

Question 7

Management

Answer 7

Prevention

• Screen blood, blood products and organ donors
• Needle exchange schemes for IV drug users
• Instrument sterilisation
• NO VACCINE AVAILABLE

Medical

• Acute - mainly supportive (antipyretics, antiemetics, cholestyramine)
• Chronic
  
  • Pegylated interferon-a
  • Ribavirin (guanosine nucleotide analogue)
  • Duration:

HCV Genotype 1 or 4: 24-48 weeks

HCV Genotype 2 or 3: 12-24 weeks

• Regular US of the liver may be needed if the patient has cirrhosis

Question 8

Complications

Answer 8

Fulminant hepatic failure

Chronic carriage of HCV

Hepatocellular carcinoma

Less common: porphyria cutanea tarda, cryoglobulinaemia, glomerulonephritis

Question 9

Prognosis

Answer 9

80% of exposed will progress to chronic carriage

Of these, 20-30% will develop cirrhosis over 10-20 years