Effects of intensive plasmapheresis on the haemostatic system

Intensive plasmapheresis was performed on 7 alloimmunized pregnant women. About 60% of the plasma volume was removed each day, Monday to Friday, with pauses over the weekends. This treatment resulted in drops in immunoglobulin levels to about 1/3 of the pre-treatment concentrations, whereas the haemostatic parameters studied remained within normal limits. Thus, generally the treatment (as performed in this study) does not seem to induce changes that predispose for thrombotic or haemorrhagic complications. However, in one of the patients, antithrombin III became progressively depleted over the weeks of treatment. Therefore it is suggested that the patients be screened for their haemostatic profile prior to and after a few weeks of plasmapheresis treatment.