Treatment of refractory myasthenia gravis by double-filtration plasmapheresis and rituximab: A case series of nine patients and literature review.

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune disease mediated by circulating autoantibodies (anti-AchR, anti-MuSK, etc.). More than 20% of myasthenic patients are refractory to conventional treatments (plasma exchange, IVIg, steroids, azathioprine, mycophenolate mofetil). Rituximab (B-lymphocyte-depleting anti-CD20) and apheresis (double-filtration plasmapheresis [DFPP] and immunoadsorption [IA]) are interesting therapeutic alternatives. METHODS: This monocentric pilot study included nine refractory myasthenic patients (March 2018 to May 2020) treated by DFPP and/or IA associated with rituximab (375 mg/m2 ). Clinical responses were assessed using the Myasthenia Gravis Foundation of America (MGFA) score. RESULTS: Average age of patients was 53 ± 17 years. Gender ratio (M/F) was 3:6. The combination of apheresis and rituximab reduced median MGFA score from IV to II after 12 months of follow-up. Clinical improvement assessed by MGFA score was sustained in the long-term for all patients, during an average follow-up of 14 ± 9 months, allowing them to be self-sufficient and out sick-leave. The median number of apheresis sessions was 7 (5-30). The dose of prednisolone was reduced in two patients from 40 mg/d and 30 mg/d to 7.5 mg/d and 10 mg/d, respectively. It was stopped in a patient who was taking 30 mg/d. No infectious, bleeding, or thrombosis complications were noted. CONCLUSION: The combination of rituximab and DFPP was effective to treat refractory MG.

How to improve clotting factors depletion in double-filtration plasmapheresis.

BACKGROUND: Double-filtration plasmapheresis (DFPP), a selective therapeutic apheresis, can deplete pathogenic antibodies/substances, but also important coagulation factors. AIM: To determine if the use of a separator filter with different characteristics (CascadefloEC-50 W) as compared to the reference filter (PlasmafloOP-08 W) is as efficient in terms of immunoglobulin loss, but can reduce coagulation factor losses and have similar tolerability. PATIENTS/METHODS: This is a single-center prospective study including 14 patients divided into two groups (7 each): that is, group1 = CascadefloEC-50 W and group2 = PlasmafloOP-08 W. We measured immunoglobulins, lipid profiles, blood-cell counts, hemostasis (prothrombin time, activated partial thromboplastin time), coagulation factors, and natural anticoagulants at before and after the first DFPP-session. RESULTS: In group 1, the loss of coagulation factors was significantly reduced as compared to group 2 for proteins with a molecular weight of >150 kDa: there was, respectively, an average decrease of 70% vs 31% for fibrinogen (P = 0.004), 66% vs 21% for factor V (P = 2.16e-07), 60% vs 32% for factor XI (P = 6.96e-06), 75% vs 17% for XIII-antigen (P = 0.0002), and 47% vs 0% for VWF-antigen(P = 0.02). The decrease in post-session IgG was, on average, 45% in group 1 and 50% in group 2 (P = 0.13). Those results remained significant even when adjusted to the treated-plasma volume and the pre-DFPP factor values. CONCLUSION: DFPP, using a CascadefloEC-50W as a first-filter, reduces efficiently IgGs similarly to PlasmafloOP-08W but spares clotting factors.

Fibrinogen reconstitution after therapeutic apheresis: Comparison of double-filtration plasmapheresis, plasma exchange, and immunoadsorption.

BACKGROUND: Fibrinogen reconstitution after therapeutic apheresis has been poorly studied. Apheresis modalities, for example, plasma exchange (PE), double-filtration plasmapheresis (DFPP), or selective immunoadsorption (IA), may have different impacts. METHODS: We retrospectively investigated therapeutic apheresis sessions performed at our center across four modalities (PE, DFPP, and IA with or without plasma filtration). Fibrinogen levels were assessed at the beginning and end of each apheresis session, and immediately before the subsequent session. We adjusted measurements on hematocrit values to account for hemoconcentration. RESULTS: Between January 10, 2016 and March 2, 2020, we included 90 patients for a total of 754 apheresis sessions (PE: 35; DFPP: 351; IA only: 109; IA + plasma filtration: 259). Each patient received a median of five sessions (1Q 3; 3Q 9); median plasma volume treated was 5.5 L (1Q 4.3 L; 3Q 7.0 L). Within a session, DFPP and PE induced a significantly greater depletion of fibrinogen than both IA modalities, even after adjustment for the treated plasma volume. Median fibrinogen reconstitution was 0.8 (0.4-1.2) g/L (median time between sessions: 38 hours). In multivariate analysis, fibrinogen reconstitution was significantly associated with intersession time (+0.66 g/L/log-hour P < .001), apheresis modality (ANOVA; P < .001), initial fibrinogen concentration (+0.15 g/L per gram of fibrinogen; P < .001), and the last fibrinogen concentration from the previous apheresis session (-0.14 g/L per gram of fibrinogen; P < .001). In a model that considered hemoconcentration, the results were unchanged. CONCLUSIONS: We demonstrate that fibrinogen reconstitution was highly variable between patients and apheresis sessions. Apheresis modalities had a significant impact on fibrinogen reconstitution, regardless of hemoconcentration.

Comparison of three modalities of plasmapheresis on coagulation: Centrifugal, single-membrane filtration, and double-filtration plasmapheresis.

BACKGROUND: Plasmapheresis can deplete pathogenic antibodies and allow ABO- and/or HLA-incompatible transplantation. AIM: To determine the impacts of three modalities of plasmapheresis (centrifugal plasmapheresis [cTPE], single-filtration plasmapheresis [mTPE], double-filtration plasmapheresis [DFPP]) on hemostasis parameters and thrombin generation. MATERIALS/METHODS: Prospective, comparative study on 21 patients that received three modalities of plasmapheresis (7 patients/group). Hemostasis (prothrombin time [PT], activated partial thromboplastin time [aPTT], procoagulant factors and natural anticoagulants) were measured before and after the first plasmapheresis session. Thrombin generation was also assessed in platelet-poor plasma using an STA-Genesia (Stago) analyzer and Thromboscreen reagents (Stago) in 4-5 patients from each group. RESULTS: Both cTPE and mTPE resulted in high decreases in proteins, whatever their molecular weights. Median post/pre ratios were 0.27 to 0.55 for cTPE for most proteins (except FVIII [0.64] and VWF [0.57]). Median post/pre-ratios of mTPE were 0.28 to 0.56 for all proteins. DFPP decreased high-molecular-weight proteins (fibrinogen, FV, FVIII, FXI, VWF) and proteins strongly bound to large molecules (protein SandTFPI). Median post/pre ratios with cTPE and mTPE were similar to DFPP for fibrinogen and FXIII. Regarding thrombin generation, cTPE and mTPE did not significantly modify endogenous thrombin potential (ETP) and DFPP induced a slight decrease in ETP (median post/pre ratio at 0.73) in the absence of thrombomodulin. ETP inhibition by thrombomodulin was decreased for all procedures. CONCLUSIONS: DFPP depleted high molecular-weight proteins in contrast to cTPE and mTPE, which significantly decreased all proteins. Regarding thrombin generation, depletion of procoagulant factors was counterbalanced by a decrease in some natural anticoagulants whatever plasmapheresis method used; with all methods, fibrinogen and FXIII were highly depleted.

Treatment of antibody-mediated rejection with double-filtration plasmapheresis, low dose IVIg plus rituximab after kidney transplantation.

Antibody-mediated rejection (ABMR) at early or late post-transplantation remains challenging. We performed a single-center single-arm study where four cases of acute ABMR and nine cases of chronic active ABMR (defined by Banff classification) were treated with double-filtration plasmapheresis (two cycles of three consecutive daily sessions with a 4-day gap between). At the end of the third and sixth DFPP sessions, the patients received rituximab 375 mg/m2 . After a median follow-up of 1078 (61-1676) days, kidney-allograft survival was 50%. Before DFPP/rituximab therapy, the median donor-specific alloantibody (DSA) mean fluorescence intensity (MFI) was 9160 (4000-15 400); 45 days (D45) later it had significantly decreased to 7375 (215-18 100) (P = .018). In addition, at one-year (Y1) post-therapy, MFI had decreased further, that is, 4060 (400-7850) (P = .001). In two patients, DSA MFIs decreased and remained below 2000. The slope of estimated glomerular-filtration rate within the 6 months preceding intervention was -1.18 mL/min/month and remained unchanged at -1.29 mL/min/month within the year after intervention. Proteinuria remained unchanged. Baseline Banff scores on repeat allograft biopsies (post-therapy D45, Y1) did not show any improvement. Side-effects were mild to moderate. We conclude that the combined DFPP/rituximab significantly decreased DSAs in ABMR kidney-transplant recipients but did not improve renal function or renal histology at 1-year follow-up.

Isoagglutinin removal by plasma centrifugation or filtration (single or double): A prospective study in a single center.

INTRODUCTION: ABO-incompatible (ABOi) kidney transplantation, a well-established procedure, has good long-term results provided pretransplant desensitization that includes immunosuppression and apheresis. OBJECTIVE: To compare, within the first pretransplant apheresis session given to 29 ABOi kidney-transplant candidates, the effect on isoagglutinin titers (both IgG and IgM isotypes) of three modalities: centrifugation therapeutic plasmapheresis (cTP; n = 10), filtration TP (fTP; n = 9), and double-filtration plasmapheresis (DFPP; n = 10). RESULTS: The three groups were comparable according to baseline demographics. Treated plasma volumes were similar across the three groups, that is, 4111 ± 403 mL (cTP), 3861 ± 282 mL (fTP), and 3699 ± 820 mL (DFPP): that is, 54 ± 7, 53 ± 7, and 53 ± 10 mL/kg respectively. One session of centrifugation or filtration TP reduced IgG anti-A/anti-B isoagglutinin titer by ~4, whereas one DFPP session reduced it by ~2. One session of cTP reduced IgM anti-A isoagglutinin titer by a little less than 4, whereas fTP and DFPP sessions reduced it by ~3. There were no statistical differences across the three groups regarding isoagglutinin rebound (IgG and IgM). However, isoagglutinin IgG rebound was >4 dilutions for anti-B titers compared with ~2 dilutions for anti-A titers. The median decreases in IgG level were -3.9 g/L (DFPP), -5.9 g/L (cTP), and - 6.06 g/L (fTP) (p = ns). Median fibrinogen depletions were ~ 60% (fTP), 64% (DFPP), and 76% (cTP). CONCLUSIONS: Isoagglutinin depletions within the first apheresis session were similar across cTP, fTP, and DFPP: this was numerically lower for DFPP.

Immunoadsorption for Recurrent Primary Focal Segmental Glomerulosclerosis on Kidney Allografts: A Single-Center Experience and Literature Review.

INTRODUCTION: Primary focal and segmental glomerulosclerosis (FSGS) frequently reoccurs on kidney transplants and may lead to premature allograft loss. There are no guidelines for treating FSGS recurrence on allografts; treatment is based on apheresis (plasma exchange plasmapheresis [PP], semi-specific immunoadsorption [IA] with reusable columns) plus rituximab. OBJECTIVE: We aimed to assess the efficacy of IA to treat recurrent FSGS. METHODS: We report on 7 patients with recurrent FSGS on kidney allograft (proteinuria ≥3 g/g of urinary creatinine or ≥3 g/day); they all received IA. Our primary objective was to reduce proteinuria by >50%. Patients' mean age was 45 ± 10 years. Postoperative immunosuppression relied on steroids, mycophenolate mofetil, tacrolimus, with an induction therapy of basiliximab or antithymocyte globulins. Prophylaxis to prevent FSGS recurrence was either rituximab alone (n = 3), rituximab plus either PP or IA (n = 3), or no treatment (n = 1). Mean follow-up was 20 ± 13 months. There was a median of 72 (14-101) IA sessions per patient, that is, a mean of 14 ± 1 sessions per IA column. RESULTS: At 12 months after starting IA, all patients had partial (n = 6) or complete (n = 1) remission, and allograft survival was 100%. The mean reduction in proteinuria within an IA session was 45 ± 15%. At last follow-up, 2 patients are in remission without IA, 3 patients are in partial remission that is IA dependent, and 2 patients lost their allograft due to FSGS recurrence. The most frequent adverse event was cytomegalovirus reactivation (n = 13), which subsided after valganciclovir therapy. CONCLUSIONS: We show that recurrence of FSGS can be controlled long term with IA plus rituximab. However, some patients remained dependent on IA.

Effect of immunoadsorption alone or combined with membrane filtration on hemostasis parameters.

INTRODUCTION: ABO- or HLA-incompatible kidney transplantation is possible thanks to pretransplant antibody-depletion achieved by extracorporeal-treatment modalities. These methods induce depletion of some plasma proteins and may also impact on proteins involved in hemostasis. METHODS: To determine the impact of one session of immunoadsorption (IA) alone or combined with membrane filtration (MF) on clotting factors and natural anticoagulants, we performed a prospective, observational study on 13 patients waiting for HLA-/ABO-incompatible kidney transplants. Plasma hemostasis parameters were measured before and immediately after a first session of IA alone in six patients and of IA + MF in seven patients. RESULTS: IA alone induced depletion of fibrinogen and factor XIII (FXIII) whereas IA + MF caused greater depletion of all high-molecular-weight hemostatic proteins (fibrinogen, FV, FVIII, FXI, FXIII, von-Willebrand factor [VWF]). After an IA session, median reductions were 30% for fibrinogen and 43% for FXIII compared to baseline values. After a session of IA + MF, median decreases were 70% for fibrinogen, 54% for FV, 56% for FVIII, 37% for FXI, 78% for FXIII, and 62% for VWF. Noticeably, levels of low-molecular-weight factors (<100 kDa) were far less decreased than high-molecular-weight proteins with IA + MF, except for protein S and the tissue factor pathway inhibitor, which are known to be partially physiologically bound to high-molecular-weight molecules. CONCLUSIONS: IA and IA + MF induced significant depletion of some proteins implicated in the hemostatic process; however, IA + MF resulted in stronger modifications to hemostasis parameters than IA alone. This may have potential clinical implications regarding bleeding risk, and particularly depletion of fibrinogen and FXIII.

Is There a Place for Apheresis in the Management of Idiopathic Membranous Nephropathy? A Report of Three Cases and Literature Review.

Membranous nephropathy constitutes approximately 20% of adult nephrotic syndrome cases. In approximately 80% of cases, membranous nephropathy is primary, mediated by IgG autoantibodies primarily targeting podocyte antigens (PLA2R, THSD7A, etc.). The treatment involves a combination of corticosteroids and cyclophosphamide or anti-CD20-based therapies, e.g., rituximab. In the event of significant proteinuria and in order to avoid the urinary elimination of rituximab, therapeutic apheresis, in particular semi-specific immunoadsorption, may be an option allowing for a reduction in proteinuria and autoantibodies before initiating treatment with rituximab. We present the preliminary experience of three patients treated with semi-specific immunoadsorption for primary membranous nephropathy between January 2021 and March 2023. Two patients were anti-PLA2R-autoantibody-positive and one was seronegative. The average age was 59 ± 17 years. Semi-specific immunoadsorption did not reduce albuminuria, but it, nevertheless, led to an increase in serum albumin, contributing to the regression of edema. It effectively eliminated anti-PLA2R autoantibodies in the two anti-PLA2R-positive patients. Consequently, apheresis may not induce a rapid reduction in proteinuria, but could contribute to a more accelerated remission when combined with the anti-CD20 treatment.

Cryoglobulinemia and double-filtration plasmapheresis: Personal experience and literature review.

BACKGROUND: Cryoglobulinemia is defined as the presence of an abnormal immunoglobulin that may be responsible for vasculitis of small-caliber vessels. Apheresis can be used in order to temporarily eliminate circulating cryoglobulins. The aim of this study was to assess the effectiveness of apheresis (double-filtration plasmapheresis-DFPP-) in symptomatic and/or severe cryoglobulinemias. METHODS: Four male patients presenting cryoglobulinemic vasculitis and who received DFPP sessions were included. RESULTS: Their mean age was 57 ± 15 years. One patient had hepatitis-C virus (HCV)-related cryoglobulinemia and the other three patients were carriers of an IgM Kappa monoclonal gammopathy. Mean duration of follow-up was 15 ± 2 months. DFPP allowed healing of ulcerative skin lesions in the first patient and remission of nephrotic syndrome in the other patients after a median of 6(5-10) sessions. CONCLUSION: DFPP can be used safely in cryoglobulinemic-vasculitis and can be considered early to achieve a faster and sustained clinical-biological response.

[How to implement a complete apheresis program within a hemodialysis unit]. / Comment mettre en place un plateau technique d'aphérèses.

Many apheresis techniques can be performed in a blood-bank facility or a hemodialysis (HD) facility. However, it makes sense to perform apheresis in a hemodialysis facility as apheresis involves extra-corporeal circuits and because HD can be performed at the same time as apheresis (tandem procedure). Apheresis techniques comprise therapeutic plasma exchange, double-filtration plasmapheresis, and its derivative (rheopheresis and LDL-apheresis), and immunoadsorption (specific and semi-specific). We have setup an apheresis platform in our hospital that fulfills health recommendations. This process has involved financial investment and significant human resources, and has enabled us to network with different specialties (neurology, hematology, vascular medicine). We have setup protocols according to the type of pathology to be treated by apheresis, and to monitor clinical and biological data for each apheresis session. The main side effects of apheresis are a fall in blood pressure when a session is initiated, an increase in fluid overload, hypocalcemia, and the loss of some essential plasmatic factors. However, these side-effects are easily identified and can be properly managed in real time. Within two-years, we have performed 1845 apheresis sessions (134 patients). Of these, 66 received apheresis before and/or after kidney transplantation for ABO and/or HLA incompatibility (desensitization), for humoral rejection, or in the setting of relapsing focal-segmental glomerulosclerosis. Our patients' outcomes have been similar to those reported in the literature. The other 68 patients had various conditions. Because our program is now well-established, we are currently forming a specialist center to train physicians and nurses in the various apheresis techniques/procedures.