A coupling device that reduces the risk of cross-contamination of dialyzers during reprocessing by providing a reusable, easily disinfected connector for coupling a dialyzer to, e.g., the blood line of a dialyzer reprocessing system. The coupling device is in the form of a one-piece adapter for being screwed to the luer connector of a dialyzer and then axially attached to a blood line of a dialyzer reprocessing device via a quick connect/disconnect coupling. The adapter is reusable and easily disinfected by soaking it in liquid disinfectant.