Effects of immunoadsorption combined with membrane filtration on complement markers - Results of a randomized, controlled, crossover study.
Defendi, F., Malvezzi, P. et al. (2019).Transplant International: 22:22.
Aims
To investigate whether adding a membrane filtration (MF) to a circuit during semi-selective immunoadsorption (IA) can enhance the elimination of ABO reactivity to remove additional macromolecular complement components, such as mannose-binding lectin (MBL) and properdin.
Interventions
Patients were randomized into two intervention sequences : a single session of IA combined with MF (IA+MF) followed by a single session of IA alone, or vice versa.
Participants
14 kidney transplant recipients.
Outcomes
Outcomes included impact of apheresis on complement activation, effect of IA+MF versus IA on properdin and MBL concentration.
Follow-up
7 days.
CET Conclusions
Antibody depletion prior to ABO or HLA incompatible transplantation has been used to facilitate transplantation in these patient groups. This good quality RCT was previously reported and the new paper describes the effect on complement depletion of combined immunoadsorption (IA) + membrane filtration (MF), compared to IA. The trial was open label, but the results presented are very objective. Levels of C5b-9b, the terminal complex of the complement cascade, were used as a marker of complement system activation. There was no significant difference in C5b-9 levels between groups pre- or post-intervention and nor was there a significant change in levels in either group. The combination of IA+MF significantly reduced levels of properdin and mannose-binding lectin compared to IA alone. Conversely, levels of properdin and mannose-binding lectin returned to pre-treatment levels at day 7 in the IA+MF group, but not in the IA alone group. This is difficult to explain and the exact mechanisms of clearance and recovery are unclear. The authors acknowledge that the carry-over effect from cross-over treatments may be the cause; the clinical implications are uncertain.
Data analysis
Per protocol analysis
Trial registration
ClinicalTrials.gov number - NCT01698736