Immunomodulating effects of serum-material interactions.

The objective of this study is to evaluate an in vitro model to assess the effects of serum-material interactions on complement activation, macromolecular adsorption, and lymphocyte response. Minifilters of clinically available materials (PVA, EVAL-4A, and EVAL-D) used in extracorporeal therapies were evaluated. The test circuit consisted of a pump, sterile tubing, collection vessels, and the minifilter. A sham circuit similar to the test circuit was constructed, but without the filter. Serum flow rates and volumes processed were scaled down to those of clinical use. Post PVA serum showed the highest degree of complement activation, macromolecular solute adsorption, and lymphocyte suppressive response when incubated with Con-A, PHA, PWM, and Candida. Post EVAL-4A sera enhanced the response of lymphocytes to Con-A and PHA, while Post EVAL-D sera showed a slight suppression to these mitogens. Blood-material interactions have been shown to cause blood cellular changes. The in vitro model employed is simple to apply and does not require an animal or patient. The membrane modules used are a mini-type of clinically available extracorporeal filters, and there is a greater direct relevancy to clinical applications than there would be using specially formulated materials. This system would provide useful preclinical information in evaluating the effects of serum-material interactions.