Background/Purpose: Despite a historically robust vaccination program, hepatitis B infection remains a significant public health challenge, and particularly for patients on chronic immunosuppressive therapy. There is a considerable risk of hepatitis B reactivation while on these medications with reports of up to 25% mortality. A complete serologic screen should include hepatitis B surface antibodies (anti-HBsAb) to assess for immunity, in addition to hepatitis B core antibodies (anti-HBcAb) and hepatitis B surface antigen (HBsAg) to evaluate for acute or chronic infection. Our aim was to collect and examine hepatitis B serology screenings on patients receiving intravenous biologic medications within rheumatology and gastroenterology (GI) at Cincinnati Children’s Hospital Medical Center (CCHMC).

Methods: We identified all rheumatology and GI patients receiving intravenous biologic medications between October 2015 and June 2016 and determined if a complete hepatitis B serology screening had previously been obtained. For patients without previous serology or with results older than 1 year, we ordered a complete panel at the time of a scheduled infusion.    

Results: During the study period, we screened a total of 307 patients (109 rheumatology, 198 GI) with an age range from 2 to 27 years (mean 15.5, SD 4.3). A majority of patients (83%) were on infliximab, including all GI patients. In addition to infliximab, rheumatology patients were also on tocilizumab (12%), abatacept (3%), belimumab (1%), rituximab (1%), and golimumab (<1%). Of the total patients tested, 62% had either a negative or indeterminate result for anti-HBsAb, representing non-immune status. The most vulnerable age range for non-immune status (anti-HBsAb negative) was 11-20 years of age (see Figure 1). Interestingly, this trend was more pronounced in rheumatology patients on infliximab versus GI patients on infliximab. Surprisingly, there was 1 rheumatology patient on infliximab who had a positive anti-HBcAb, indicating chronic infection that presumably occurred via transplacental transmission. However, no patients had a positive HBsAg, or evidence of active infection.

Conclusion: Results from this study support the need for routine hepatitis B screening in immunocompromised patients. We determined that a majority of our patients on intravenous biologic medications were seronegative for hepatitis B and will require repeat vaccination. We also identified 1 patient with evidence of chronic infection who is now being closely monitored by hepatology. Our next steps include expanding hepatitis B screening to all patients identified as immunocompromised in rheumatology clinic; further investigating differences between rheumatology and GI immunity; and collecting post-vaccination serology data on patients who require repeat vaccination.