REMOVAL OF CYTOKINES AND ACTIVATED COMPLEMENT COMPONENTS IN AN EXPERIMENTAL-MODEL OF CONTINUOUS PLASMA FILTRATION COUPLED WITH SORBENT ADSORPTION

Background. Sepsis is associated with enhanced cytokine production. He re, we examined the in vitro removal of plasma cytokines during contin uous plasmafiltration coupled with sorbent adsorption. Methods. Proinf lammatory (tumour necrosis factor-alpha, interleukins-l, -8)and anti-i nflammatory (interleukin 1 receptor antagonist, soluble tumour necrosi s factor receptor type I and II) cytokines in whole blood spiked with Escherichia coli endotoxin were determined during 2-h recirculation in the ultrafiltrate (condition A), plasma filtrate (condition B), befor e and after different sorbents (of the Amberlite(R)-, Amberchrome(R)-A mbersorb(R) -type and charcoal). We studied the maximal adsorbing capa city, the 1% leakage test for cytokines and C3a des Arg and the adsorp tion of complement-dependent leukocyte chemiluminescence. Plasma prote ins eluted from the resins were examined by sodium dodecyl sulphate po lyacrylamide gel electrophoresis and immunoblotting with an anti-human alpha(2)-macroglobulin . Results. In condition B, we observed a 40- a nd 121-fold % increase (vs condition A) in the removed mass and cleara nce of tumour necrosis factor-alpha. For all other cytokines, the remo ved mass and the clearance increased from 2.3- up to 6-fold. The Amber chrome(R) but not the Amberlite(R) or Ambersorb(R) resins could remove the highest amount of cytokines and could reduce complement-dependent chemiluminescence. Two protein bands of approximately 400 000 D and 2 00 000 D were eluted only from Amberchrome(R) resins and immunoprecipi tated by anti-human alpha(2)-macroglobulin and anti-human C3c antibodi es, respectively. Conclusions. These studies suggest an efficient remo val of cytokines in continuous plasmafiltration with sorbent adsorptio n. The binding of alpha(2)-macroglobulin, a carrier of cytokines in pl asma, might be a additional mechanism in the removal of cytokines from plasma.