Intermittent hepatitis B surface antigenuria in a renal transplant recipient

It has been demonstrated that hepatitis B surface antigen (HB₈Ag) can be detected in the urine of a majority of persistent serum carriers of HB₈Ag undergoing hemodialysis with urinary output. Therefore we have proposed that, in this population, urine may represent a potential vehicle for nonparental transmission of hepatitis B. Described here is a renal transplant recipient with intermittent HB₈Ag in the urine who has never been subjected to hemodialysis and who underwent bilateral nephrectomy before renal transplantation. Determinations of HB₈Ag or antibody to HB₈Ag (anti-HB₈) in serum obtained from this patient and three household contacts, as well as in serial urine samples from the patient, were performed by radioimmunoassay. The patient has consistently had HB₈Ag in her serum (HB₈Ag positive) (subtype ad) for at least three years. Four of five urines obtained over a four-month period also contained HB₈Ag. Two serum samples, one year apart, obtained from the son of this index patient both contained HB₈Ag. Serum samples from her former husband and a current cohabitant were void of HB₈Ag, but did contain anti-HB₈, indicating previous exposure to hepatitis B. We believe this information implicates the index patient as a potential source of hepatitis B to a number of persons. The epidemiologic consequences of HB₈Ag positive persons receiving a renal transplant have not been adequately emphasized. Furthermore, the presence of HB₈Ag in the urine eight years after a bilateral nephrectomy and successful renal transplantation suggests that the transplanted kidney allows passage of HB₈Ag into the urine and that the presence of an end-stage kidney is not required for antigenuria. Finally, because successful renal transplantation results in normal urine volume and increased interaction of the recipient with the general population, the urine of HB₈Ag carriers could have an important role in the spread of hepatitis B.