Haemodialysis activates phospholipase A2 enzyme

Abstract

Background. Clinical and experimental evidence suggest that haemodialysis (HD) procedure is an inflammatory process. For the production of proinflammatory lipid mediators in many inflammatory reactions, the release of arachidonic acid by phospholipase A 2 (PLA 2 ) enzyme is a prerequisite. Therefore, the purpose of the present investigation was to establish whether the activity of PLA 2 increases during HD and whether the increase depends on the type of dialyser used. Methods. We performed dialysis in eight chronic HD patients. Blood samples entering and leaving the dialyser were obtained before and at 15, 60, 120 and 180 min after the dialysis was started, on one occasion using a cuprophane and on another occasion a cellulose triacetate dialyser. PLA 2 activity was assessed in crude plasma and in plasma extract. Results. PLA 2 activity in plasma extract exhibited similar biochemical properties to that of inflammatory human synovial fluid PLA 2 enzyme which is of group II PLA 2 . PLA 2 activity in crude plasma represents a type of PLA 2 other than the synovial type. In HD patients, baseline PLA 2 activities in crude plasma and plasma extract were significantly increased when compared to normal subjects. An increase in PLA 2 activity was observed in crude plasma with a peak appearing at 15 min when the patients were dialysed with cuprophane and cellulose triacetate membranes. This increase was observed in both arterial and venous blood samples and was more pronounced when the patients were dialysed with cuprophane than with cellulose triacetate membranes. When PLA 2 was assessed in plasma extract, the activity increased only with cuprophane but not with cellulose triacetate membranes. Conclusion. PLA 2 activity in plasma is increased in HD patients and increases during the dialysis procedure to a greater extent with a less biocompatible membrane. Continuous activation of PLA 2 might be relevant for long-term deleterious consequences of HD.

Comparison of continuous and intermittent renal replacement therapy for acute renal failure

“…Furthermore, it is unknown whether the clearance of pro-inflammatory endobiotics by the extracorporeal therapy is not outweighed by a similar or even more pronounced removal of their natural antagonists [8]. On the other hand, dialysis procedures are pro-inflammatory by themselves as a consequence of blood-membrane contact [10][11][12]. Thus, it is conceivable that a shorter duration of blood-membrane contact as in IHD might diminish the overall exposure of the patients to inflammatory mediators.…”

Effect of Intravenous ω‐3 Fatty Acid Infusion and Hemodialysis on Fatty Acid Composition of Free Fatty Acids and Phospholipids in Patients With End‐Stage Renal Disease

“…First, heparin administered at the initiation of HD releases endothelium‐associated lipoprotein lipase, 34 which cleaves FFAs from triglycerides. Second, because of the inflammatory effect of HD, phospholipase A 2 may be upregulated, resulting in the release of FFAs from phospholipids 35 . Third, the stress and adrenergic stimulation related to HD treatment may increase FFAs.…”

Does Continuous Venovenous Hemodiafiltration Concomitant with Radiological Procedures Provide a Significant and Safe Removal of the Iodinated Contrast Ioversol?

“…Despite its efficacy in CM extraction, hemodialysis sessions performed after radiological investigations/interventions have not convincingly improved the prognosis [12,13,17]. This inefficiency may be a result of the incomplete biocompatibility of the dialyzers and subsequent enhancement of inflammatory and coagulation processes [19,20], of the dysequilibrium and hemodynamic instability induced by the rapid removal of osmotic values or of late removal of CM (renal hypoperfusion and probably ischemia occurring in the first minutes after the injection of CM [21,22]). In previous studies hemodialysis was always performed after radiological investigation/intervention, procedures that sometimes last very long.…”