To avoid Hep B reactivation, screen before immunosuppression
Universal HBV screening before immunosuppression is prudent and cost effective, even when local HBV prevalence is just 0.3%.
PRACTICE RECOMMENDATIONS
› Measure levels of hepatitis B surface antigen and core antibody total. Although testing for IgG alone can be acceptable, testing for IgM alone is unacceptable. C
› Use both a patient’s serologic findings and the recognized risk associated with intended therapy to determine the threat of hepatitis B virus (HBV) reactivation. C
› Offer antiviral prophylaxis when risk for HBV reactivation is high. Consider prophylaxis or monitoring for those at moderate risk. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
The justification for universal screening
Although nongastroenterology societies differ in their recommendations on screening for HBV, universal screening before implementing prolonged immunosuppressive treatment is recommended by the CDC,6 the American Association for the Study of Liver Diseases,18 the Asian Pacific Association for the Study of the Liver,19 the European Association for the Study of the Liver,20 and the American Gastroenterological Association (AGA).21
Older guidelines recommended screening only high-risk populations. But such screening has downfalls. It requires that patients or their physicians recognize that they are at high risk. In one study, nearly 65% of an infected Asian-American population was unaware of their positive HBV status.22 Risk-based screening also requires that physicians ask the appropriate questions and that patients admit to high-risk behavior. Screening patients based only on risk factors may easily overlook patients who need prophylaxis against HBVr.
Common arguments against universal screening include the cost of testing, the possibility of false-positive results, and the implications of a new diagnosis of hepatitis B. However, the potential benefits of screening are significant, and HBV screening in the general population has been shown to be cost effective when the prevalence of HBV is 0.3%.21 In the United States, conservative estimates are a prevalence of HBsAg positivity of 0.4% and past infection of 3%, making screening a cost-effective recommendation.16 It is therefore prudent to screen all patients before starting immunosuppressive therapy.
How to screen
All guidelines agree on how to test for HBV. Measuring levels of HBsAg and hepatitis B core antibody (anti-HBc total) allows the clinician to ascertain whether the patient’s HBV infection status is acute, chronic, or resolved (TABLE 223) and to perform HBVr risk stratification (discussed later).
Patients with acute infections should be referred to a hepatologist. With chronic or resolved HBV, stratify patients into a prophylaxis group or monitoring group (FIGURE14). Stratification involves identifying HBV status (chronic or resolved) and selecting a type of immunosuppressive therapy. Whether the patient falls into prophylaxis or monitoring, obtain a baseline level of viral DNA, as this has proven to be the best predictor of HBV reactivation.16
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