No plasma donors. Old plasma is replaced with saline and albumin.
In plasma donation – which can be done in return for cash compensation in the USA! – 20% of a body's plasma is replaced with saline solution (no albumin).
Plasma donation might plausibly approximate this study's effects, at a lesser level.
Generally plasma donation is allowed every 28 days, though in some cases 3 donations over 8 weeks (or about once every 12 days) is allowed.