Extracorporeal adsorption of protective and toxic bile acids and bilirubin in patients with cholestatic liver dysfunction: a prospective study

Abstract

Abstract Background The release of toxic bile acids (BAs) in the blood of critically ill patients with cholestatic liver dysfunction might lead to the damage of various organs. Their extracorporeal elimination using the cytokine adsorber Cytosorb® (CS) (adsorption of especially hydrophobic molecules < 60 kDa) might be promising, but data proving a potential adsorption are missing so far. Methods The prospective Cyto-SOVLE study (NCT04913298) included 20 intensive care patients with cholestatic liver dysfunction, continuous kidney replacement therapy, total bilirubin concentration > 10 mg/dl and the application of CS into the dialysis circuit. Bilirubin and different BAs were measured pre- and post-CS at defined timepoints (10 min, 1, 3, 6, and 12 h after initiation). Relative reduction (RR, %) was calculated with: $$1-\left(\frac{\mathrm{concentration} (\mathrm{pre}-\mathrm{post})}{\mathrm{concentration} (\mathrm{pre})}\right)*100$$ 1 - concentration ( pre - post ) concentration ( pre ) ∗ 100 . Results The median RR for total and conjugated bilirubin after initiation was − 31.8% and − 30.3%, respectively, and decreased to − 4.5% and − 4.8% after 6 h. A high initial RR was observed for the toxic BAs GCA (− 97.4%), TCA (− 94.9%), GCDCA (− 82.5%), and TCDCA (− 86.0%), decreasing after 6 h to − 32.9%, − 32.7%, − 12.8%, and − 14.3%, respectively. The protective hydrophilic BAs showed a comparable RR after initiation (UDCA: − 77.7%, GUDCA: − 83.0%, TUDCA: − 91.3%) dropping after 6 h to − 7.4%, − 8.5%, and − 12.5%, respectively. Conclusions Cytosorb® can adsorb bilirubin and toxic as well as protective BAs. However, a fast saturation of the adsorber resulting in a rapid decrease of the RR was observed. Furthermore, no relevant difference between hydrophobic toxic and hydrophilic protective BAs was detected regarding the adsorption amount. The clinical benefit or harm of the BA adsorption needs to be evaluated in the future.