Swim-up as a strategy for isolation of spermatozoa without viral incorporation in men with chronic hepatitis B: A pilot study

Hepatitis B virus (HBV) incorporates into spermatozoa which raises safety concerns about paternofetal transmission performing intracytoplasmatic sperm injection (ICSI) in men with chronic hepatitis B (cHB). HBV reduces sperm cell motility, assuming spermatozoa with highest motility are least HBV-incorporated. This study investigates an ICSI preparation technique (swim-up) to isolate most motile spermatozoa in order to select HBV-free spermatozoa. Semen and blood samples were collected from four patients with cHB. Spermatozoa were incubated in trajectories of gamete medium to create non-motile, motile/non-progressive and motile/progressive fractions. After DNA-extraction, HBV DNA loads were determined in every fraction. Participants (mean age 31) were HBsAg+(4/4), anti-HBc+(4/4) and HBV DNA+(2/4). They were treated (3/4) with entecavir(1/4) or tenofovir (2/4) and had no adverse sperm parameters(3/4). CRP-gene was detected in 95/96 sample fractions, proving successful DNA-extraction. HBV DNA was detected in none of the sample fractions, except for the motile, non-progressive fraction of one patient (HBeAg+, HBV DNA+). Since no HBV DNA was detected in progressive fractions, this study suggests swim-up a successful strategy to select HBV-free spermatozoa. Since all but one fraction was HBV DNA-negative, this study also suggests that patients with well-controlled disease have no HBV-contaminated sample fractions. This study encourages evaluation of guidelines restricting reproductive possibilities in men with cHB.