Cost-effective and safe ambulatory long-term immunoprophylaxis with intramuscular instead of intravenous hepatitis B immunoglobulin to prevent reinfection after orthotopic liver transplantation

Background: Hepatitis B (HBV)-infected patients receive an anti-HBs immunoprophylaxis [hepatitis B immunoglobulin (HBIG) titre of more than 100 IU/L] in combination with lamivudine to prevent reinfection after orthotopic liver transplantation (OLT). In comparison with intramuscular (i.m.) HBIG, costs for intravenous (i.v.) HBIG are found to be extremely high. We therefore studied patients' outcome (i) after a switch from i.v. to i.m. HBIG and (ii) the outcome after the patients were initially treated with i.m. HBIG after discharge from the hospital. Methods: (i) Six outpatients were switched from 2000 IU i.v. HBIG (Hepatect(R)) administered every 2 wk to 2000 IU i.m. HBIG (Hepatitis-B-Immunglobulin Behring(R)) given once a month. (ii) Six other outpatients were directly treated with i.m. HBIG every 4 wk after OLT. All patients also received 100 mg lamivudine/d. Results: Patients switched from i.v. to i.m. HBIG had stable anti-HBs titres (i.v. HBIG: 180+/-37 IU/L vs. i.m. HBIG: 173+/-23 IU/L). Patients directly treated with i.m. HBIG also had sufficient anti-HBs titres (176+/-31 IU/L). Intramuscular application of HBIG was well tolerated by all patients and no side-effects were observed in patients receiving i.m. HBIG. In comparison with the protocol using i.v. HBIG, the costs of i.m. treatment were 60% lower. Conclusion: Long-term administration of i.m. HBIG saves up to 60% of the usual costs for i.v. prophylaxis of HBV reinfection in patients after OLT. In combination with lamivudine, long-term i.m. HBIG therapy is as efficient as i.v. HBIG treatment, but its lower costs clearly favour its use in preventing HBV reinfection after OLT.