Brodersen, H.-P.; Holtkamp, W.; Larbig, D.; Beckers, B.; Thiery, J.; Lautenschläger, J.; Probst, H.-J.; Ropertz, S.; Yavari, A.; Brodersen H.-P.; Medical Department; Holtkamp W.; Medical Department; Larbig D.; Medical Department; Beckers B.; Institute of Laboratory Medicine; Thiery J.; Institute of Clinical Chemistry, University Clinic; Lautenschläger J.; Private Dialysis Institutes in Viersen; Probst H.-J.; Private Dialysis Institutes in Viersen; Ropertz S.; Private Dialysis Institutes in Viersen; Yavari A.; Private Dialysis Institutes in Viersen