Rationale for surrogate testing to detect non-A, non-B hepatitis.

Area of Science:

• Hepatology
• Virology
• Public Health

Background:

• Non-A, Non-B (NANB) hepatitis identified in 1975, with etiology remaining unclear.
• Acute illness is often mild, but significant chronic infection (50%) and severe liver disease (10-20%) can develop.
• Posttransfusion hepatitis affects approximately 2% of transfusion recipients.

Purpose of the Study:

• To evaluate the risk of posttransfusion hepatitis.
• To assess the efficacy of surrogate testing for reducing NANB hepatitis transmission.
• To inform the implementation of risk-reduction procedures.

Main Methods:

• Review of evidence from 1970s studies on surrogate markers (ALT and anti-HBc).
• Analysis of the lack of randomized, controlled prospective studies on surrogate testing effectiveness.
• Examination of the decision to implement surrogate testing in the absence of specific diagnostic tests.

Main Results:

• Specific tests for NANB hepatitis were unavailable and unlikely in the near future.
• Surrogate tests (ALT and anti-HBc) showed potential in identifying infectious donors in earlier studies.
• Randomized trials to confirm the efficacy of surrogate testing in reducing posttransfusion hepatitis were not conducted.

Conclusions:

• Surrogate testing was implemented in the US (1986-87) as the best available method to reduce posttransfusion hepatitis.
• The decision was based on indirect evidence due to the absence of specific diagnostic tools and planned clinical trials.
• Ongoing vigilance and research are crucial for managing transfusion-transmitted viral hepatitis.