Efficacy of plasmapheresis and semi‐selective immunoadsorption for removal of anti‐HLA antibodies

Abstract

Background In organ transplantation, apheresis is frequently used for removal of anti‐HLA antibodies. However, it is unclear whether plasmapheresis (PP) or semi‐selective immunoadsorption (IA) should be employed, and the optimal number of apheresis sessions required to reach post‐treatment objectives is also unknown. Methods We enrolled 43 patients from Bordeaux University Hospital who were treated with PP (n = 29) or IA (n = 14) for antibody‐mediated rejection or pre‐transplant desensitization. Using Luminex single‐antigen flow beads, we assessed the initial mean fluorescence intensity (MFI) of 1416 positive beads with MFIs obtained after 7 to 8 apheresis sessions (extended protocol) and, if a serum was available, after the first four sessions (short protocol). Results MFI reduction after extended apheresis protocol was stronger with IA [87% (61%‐100%)] than with PP [73% (22%‐100%)] (P < .001). Indeed, 59% of the beads had a final MFI < 2000 with IA, whereas only 38% with PP (P < .001). The efficacy of removal depended on initial MFI but not on HLA specificity. A short protocol of apheresis showed excellent results without superiority of IA over PP for antibodies with an initial MFI < 3000. For antibodies showing MFI ≥2000 after four sessions, the residual MFI predicted the effectiveness of four additional sessions. Conclusion Monitoring the MFI of anti‐HLA antibodies before and during apheresis protocol can guide physicians in the selection of apheresis technique and the number of sessions to be performed.

Efficacy of Combined Desensitization Therapy Based on Protein A Immunoadsorption on Anti-human Leukocyte Antigen Antibodies in Sensitized Kidney Transplant Recipients: A Retrospective Study

“…Jambon et al [ 15 ] argued that antibody clearance effects are subjected to the initial antibody values rather than the antibody type or specificity, and that antibody clearance efficiency is negatively correlated with the initial value, which is consistent with our study’s conclusions. Moreover, we added the number of treatments to the correlation analysis between the initial value and clearance rate of different types of antibodies and found that the antibody clearance efficiency was subjected to multivariate rather than univariate effects.…”

“…In the late phase of PA-IA therapy (session 10), the clearance effects for class II antibodies increased gradually as the number of sessions increased, and the difference compared with class I antibodies became insignificant, with class I and II antibodies showing a reduction of 66.80% (33.17% to 90.48%) and 71.14% (26.95% to 100.00%), respectively (p>0.05). Additionally, after the PA-IA therapy (session 10), the levels of class I and II antibodies were essentially the same at 3196 15. (676.54 to 9266.92) and 2773.29 (415.95 to 11,192.52), respectively (p=0.617) as seen above in Table 1 and Figures 1-2 below.…”

“…Thus, research on this technique has been expanding in the fields of organ transplantation and autoimmune diseases [ 11 - 12 ]. In kidney transplantation, a previous study [ 13 ] revealed that PA-IA therapy can effectively reduce the mean fluorescence intensity (MFI) of HLA antibodies and that it is superior to plasma exchange in reducing HLA antibody levels [ 14 - 15 ]. Researchers have investigated the impact of HLA antibody characteristics (e.g., differences in antibody type, antibody specificity, and titer/MFI) on antibody clearance effects to predict the effectiveness of desensitization therapy and formulate more effective treatment regimens based on the different pre-desensitization antibody characteristics.…”

Desensitization in Crossmatch-positive Kidney Transplant Candidates

“…In addition, some authors report a linear relationship between the initial MFI of anti-HLA antibodies and their percentage reduction after >4 apheresis sessions. 64 Indeed, the percentage MFI reduction after >4 apheresis sessions was 78%–95% if the initial MFI was below 6000 and was 52%–78% if the initial MFI was 6000–12 000.…”

Novel insights in the clinical management of hyperimmune patients before and after transplantation

“…Conversely, recent study has evidenced the efficacy of anti-HLA antibody removal after PP and semi-selective IA protocols before and after organ transplantation ( Sipahi et al, 2019 ; Jambon et al, 2021 ). Furthermore, also a reduction of initial MFI value in relationship with the number of PP and IA has been observed ( Yamada et al,2015 ; Maillard et al, 2015 ; Pinelli et al, 2019 ).…”