Evaluation of the treatment volume and removal rate of Rheocarna: A novel adsorption-type blood purification device for patients with chronic limb-threatening ischemia.

INTRODUCTION: Chronic limb-threatening ischemia (CLTI) is a clinical syndrome defined by peripheral arterial disease (PAD) combined with rest pain, gangrene, or leg ulceration for longer than two weeks resulting in lower extremity amputation. In recent years, low-density lipoprotein apheresis (LDL-A) has been implemented for PAD treatment. However, it has not been possible to ensure insurance coverage for patients with lower LDL levels than 140 mg/dL under cholesterol-lowering drugs. Rheocarna is a novel adsorption-type blood purification device for the treatment of CLTI by adsorbing LDL and fibrinogen (Fib) that is not constrained by hypercholesterolemia and is not amenable to or nonresponsive to revascularization surgery. The only requirements for use are that the blood flow rate increases up to 200 mL/min gradually. METHODS: To evaluate the applicability of this treatment procedure, we compared the removal rates of Fib and LDL following Rheocarna therapy using various blood treatment volumes (6, 10.5, and 19.5 L). RESULTS: Fib and LDL removal rates were about 20% and 15%-25% per treatment, with no significant differences between treatment volumes. Following treatment with Rheocarna, blood pressure tends to decrease at first, which later increases, and the higher the treatment volume, the longer the time of low blood pressure tended to be. CONCLUSION: Although no significant difference was found in the removal rate of Fib and LDL in response to increase volume to 6 L or beyond in this study, the 6 L volume is considered effective enough for the removal of Fib and LDL.

Extended pleurectomy/decortication and hyperthermic intraoperative intrapleural cisplatin perfusion for malignant pleural mesothelioma.

Objective: To evaluate the efficacy of multimodality treatment including extended pleurectomy/decortication (P/D) and hyperthermic intraoperative chemotherapy (HIOC) with cisplatin for malignant pleural mesothelioma (MPM), we investigated the pharmacokinetics of platinum, adverse events after HIOC, and survival outcome. Methods: Fifty-three patients with pathologically diagnosed MPM (cT1-3N0-1M0, excluding sarcomatoid) underwent an extended P/D and HIOC (cisplatin 80 mg/m2 in saline 2 L, 42°C, 60 minutes) since 2011. The protocol includes postoperative 4 cycles of cisplatin and pemetrexed. Platinum concentrations in the perfusate (before and after) and the serum (1, 2, 4, 8, 24, 48, 72 hours after perfusion) were measured in 10 patients. Mortality and morbidity, especially adverse events of renal function, were investigated, and survival and affecting factors were examined. Results: All patients obtained macroscopic complete resection and pathologic staging revealed as follows: T1/2/3/4: 12/8/23/10, N0/1: 36/17, stage 1A/1B-3A/3B: 12/31/10, respectively. Platinum concentrations in the perfusate indicated that 28% of the dose remained in the pleural cavity, and the maximum concentration in the serum was 0.91 µg/mL. Six patients (11%) showed elevated max-creatinine (>2 mg/dL) postoperatively. Two patients (4%) received renal-replacement therapy, and one was weaned before discharge. There was no 30-day mortality and one in-hospital death (1.9%). Forty-six patients (87%) received multiple cycles of perioperative systemic chemotherapy. Median overall survival (OS) and disease-free survival (DFS) were 52.4 months and 18.7 months. Patents with stage 1A demonstrated a 5-year OS of 67.3% and a median DFS of 67.1 months, and patients with stage 1B-3A demonstrated a 5-year OS of 50.1% and a median DFS of 20.4 months. Univariate analysis showed histological subtype, p-T, p-stage, and multimodality treatment as significant factors affecting OS. Multivariate analysis revealed histology, p-stage, and multimodality as independent. Conclusions: Extended P/D and HIOC with cisplatin for MPM is acceptable with limited acute kidney injury. This multimodality protocol provides promising favorable survival for stage 1A-3A disease.

Adjustment by hematocrit level in calculation of removal rate in therapeutic apheresis.

Plasma volume (PV) variation during therapeutic apheresis (TA) (such as plasma exchange [PE] and selective PE using albumin solution as replacement solution or immunoadsorption plasmapheresis) has been considered to be unignorable. It changes the concentration of the target molecule and might impact its removal rate (RR.) This study aimed to evaluate the effects of PV variation on the calculation of the RR of fibrinogen and immunoglobulin by categorizing the hematocrit (Ht) change during TA into two patterns, that is, increased group and decreased group. In all modalities of TA, the Ht level frequently changed during apheresis sessions. In calculating RR, RR calculated with Ht adjustment was significantly higher than that calculated without adjustment in the increased group and significantly lower than it in the decreased group. Therefore, RR might have been underestimated in the increased group and overestimated in the decreased group when RR was calculated without Ht adjustment. Ht adjustment is suggested to be crucial in calculating RR in TA.

Removal Characteristics of Immunoadsorption with the Tryptophan-Immobilized Column Using Conventional and Selective Plasma Separators in the Treatment of Myasthenia Gravis.

Autoimmune neurological diseases are often treated by immunoadsorption using a conventional plasma separator and tryptophan-immobilized column (IA). However, there is only one case report on treatment with immunoadsorption using a selective plasma separator and tryptophan-immobilized column (SeIA) in clinical practice. This study aimed to investigate the removal characteristics of antibodies against acetylcholine receptors (AChRAb), immunoglobulin G, fibrinogen, and factor XIII (FXIII) in IA and SeIA in four patients with myasthenia gravis. A total of 19 sessions of immunoadsorption were performed (five sessions of IA and 14 sessions of SeIA) when the processed plasma volume was 2 L. The corresponding reductions were 52.5% ± 6.2% for AChRAb, 58.8% ± 4.2% for fibrinogen, and 36.9% ± 5.5% for FXIII after one session of IA. The corresponding reductions were 45.2% ± 9.9% for AChRAb, 3.5% ± 6.9% for fibrinogen, and -4.6% ± 11.1% for FXIII after one session of SeIA. The removal rates for AChRAb, fibrinogen, and FXIII in IA were significantly higher than those in SeIA. IA could effectively remove AChRAb, and SeIA could retain fibrinogen and FXIII. IA can be combined with SeIA, resulting in both IgG autoantibodies removal by IA and retention of coagulation factors by SeIA.

Removal Dynamics of Autoantibodies, Immunoglobulins, and Coagulation Factors by Selective Plasma Exchange on Three Consecutive Days.

Selective plasma exchange has been shown to be effective in various diseases, but no studies have assessed the benefits of daily treatment. We aimed to investigate the removal dynamics of immunoglobulins, fibrinogen, and factor XIII on three consecutive days in three patients. For mean processed plasma volumes of 1.06 × plasma volume, reductions of 79.6%, 49.3%, and 8.6% were seen for immunoglobulins G, A, and M, respectively. The reductions for fibrinogen and factor XIII were 18.4% and 13.0%, respectively. Removal dynamics were similar for immunoglobulin G-related autoantibodies and immunoglobulin G when using daily selective plasma exchange. Moreover, daily use effectively removed the immunoglobulin G while retaining the coagulation factors. When disease-specific autoantibodies are limited to immunoglobulin G, daily selective plasma exchange may be a useful and safe method of intensive induction treatment for plasmapheresis. However, further study is required in larger cohorts to confirm these findings.

Selective Plasma Exchange for the Removal of Pemphigus Autoantibodies, Fibrinogen, and Factor XIII in Pemphigus Vulgaris.

Pemphigus vulgaris is a serious autoimmune skin disorder associated with desmoglein 1 and 3. Selective plasma exchange (SePE) for pemphigus vulgaris remains unknown. We investigated the removal characteristics of pemphigus autoantibodies, immunoglobulins, and fibrinogen in three cases. When the mean processed volume for SePE was 1.2 plasma volumes, the mean percent reduction was 50.7% for desmoglein 1, 48.9% for desmoglein 3, 50.3% for IgG, 29.8% for IgA, 1.9% for IgM, and 17.6% for fibrinogen. In one case, the percent reduction after four sessions of SePE within eight days was 87.0% for desmoglein 1, 85.1% for desmoglein 3, 76.6% for IgG, 53.5% for IgA, 7.9% for IgM, 41.6% for fibrinogen, and 31.4% for factor XIII. SePE can effectively remove pemphigus autoantibodies and retain coagulation factors, e.g. factor XIII and fibrinogen. In severe cases, SePE can be useful and safe for induction therapy.

Fibrinogen Reduction During Selective Plasma Exchange due to Membrane Fouling.

Fibrinogen is substantially reduced by most plasmapheresis modalities but retained in selective plasma exchange using Evacure EC-4A10 (EC-4A). Although EC-4A's fibrinogen sieving coefficient is 0, a session of selective plasma exchange reduced fibrinogen by approximately 19%. Here, we investigated sieving coefficient in five patients. When the mean processed plasma volume was 1.15 × plasma volume, the mean reduction of fibrinogen during selective plasma exchange was approximately 15%. Fibrinogen sieving coefficient was 0 when the processed plasma volume was 1.0 L, increasing to 0.07 when the processed plasma volume was 3.0 L, with a mean of 0.03 during selective plasma exchange. When fibrinogen sieving coefficient was 0, selective plasma exchange reduced fibrinogen by approximately 10%. Scanning electron microscopy images revealed internal fouling of EC-4A's hollow fiber membrane by substances such as fibrinogen fibrils. Thus, fibrinogen reduction by selective plasma exchange may be predominantly caused by membrane fouling rather than filtration.

Removal Dynamics of Immunoglobulin and Fibrinogen by Conventional Plasma Exchange, Selective Plasma Exchange, and a Combination of the Two.

While plasma exchange (PE) can eliminate plasma proteins, including all immunoglobulin (Ig) and coagulation factors, selective plasma exchange (SePE) can retain fibrinogen (Fbg). Here, we investigated the removal dynamics of Ig and Fbg in 53 patients with immunological disorders by PE, SePE, and a combination of the two. When the mean processed plasma volume (PPV) was 0.9 plasma volume (PV), the mean percent reductions of Ig and Fbg by PE were both approximately 62%-65%. When the mean PPV was 1.1 PV, the mean percent reductions by SePE were 53.1% for IgG, 30.1% for IgA, 3.6% for IgM, and 19.0% for Fbg, respectively. In the three plasmapheresis sessions performed on alternate days, we classified treatments into three categories: PE group (PE-PE-PE, N = 2), SePE group (SePE-SePE-SePE, N = 14), and PE/SePE group (PE-SePE-SePE, N = 4). The mean percent reductions of IgG, IgA, IgM, and Fbg were 82.0%, 80.4%, 87.3%, and 80.9%, respectively, for the PE group; 76.4%, 57.7%, 43.3%, and 35.9%, respectively, for the PE/SePE group; and 75.4%, 50.6%, 3.2%, and 29.3%, respectively, for the SePE group. Plasmapheresis modalities can be combined according to clinical conditions, for instance, to achieve both the unspecific removal of pathogens by PE and retention of coagulation factors, such as Fbg, by SePE.

Removal Characteristics of Immunoadsorption With the Immusorba TR-350 Column Using Conventional and Selective Plasma Separators.

In Japan, immunoadsorption (IA) is performed using a conventional plasma separator and Immusorba TR-350 column (TR-350) for the treatment of neurological immune diseases. By this method, TR-350 has the limited maximal capacity of the immunoglobulin G (IgG) adsorption, and fibrinogen (Fbg) is reduced remarkably. Evacure EC-4A10 (EC-4A) is a selective plasma separator and the sieving coefficients of IgG and Fbg using EC-4A were 0.5 and 0, respectively. Here, we investigated the removal characteristics of IgG and Fbg in IA by TR-350 using two different plasma membrane separators: conventional plasma separator (PE-IA) and EC-4A (EC-IA). In vitro filtration using plasma effluent was performed with a closed circuit. When the processed volume was 3 L, estimated removal amounts by PE-IA were 3172 mg for IgG and 3329 mg for Fbg, respectively. When the processed volume was 3 L, estimated removal amounts by EC-IA were 4946 mg and 1916 mg, respectively. EC-IA can be considered useful for the removal of IgG, including auto-antibodies, while retaining Fbg, thereby allowing even daily use.

Removal Characteristics of Immunoglobulin G Subclasses by Conventional Plasma Exchange and Selective Plasma Exchange.

Selective plasma exchange (SePE) using a selective membrane separator is a modified method of simple plasma exchange (PE). Immunoglobulin G (IgG) subclass distribution is one of the important immunological characteristics of IgG. However, there is little information regarding the removal characteristics of IgG subclasses by SePE and conventional PE. Here, we investigated the removal ratio of IgG subclasses by PE and SePE in seven patients with immunological disorders. When the mean processed volume was 0.88 plasma volume (PV) (corresponding to 2.12 L), the mean percent reductions by PE were as follows: IgG, 63.2%; IgG1, 64.5%; IgG2, 64.0%; IgG3, 61.4%; and IgG4, 69.5%. When the mean processed volume was 1.18 PV (corresponding to 2.98 L), the mean percent reductions by SePE were as follows: IgG, 51.6%; IgG1, 55.3%; IgG2, 52.0%; IgG3, 53.7%; and IgG4, 64.6%. In both PE and SePE, using albumin solution as the supplementary fluid, IgG was effectively eliminated regardless of IgG subclasses.

Removal kinetics of antibodies against glutamic acid decarboxylase by various plasmapheresis modalities in the treatment of neurological disorders.

Plasmapheresis is one of the acute treatment modalities for neurological disorders associated with antibodies against glutamic acid decarboxylase (anti-GAD). However, there is little information about the removal kinetics of anti-GAD by various plasmapheresis modalities. Here, we investigated the removal rate of anti-GAD and fibrinogen (Fib) by immunoadsorption (IA), plasma exchange using a conventional plasma separator (OP-PE), and plasma exchange using a high cut-off selective membrane plasma separator (EC-PE) in two cases of anti-GAD-associated neurological diseases. In case 1, IA and OP-PE were used, and the percent reductions were as follows: anti-GAD: 38.2% and 69.1% and Fib: 67.7% and 68.2%, respectively. In case 2, OP-PE and EC-PE were used, and the percent reductions were as follows: anti-GAD: 65.8% and 48.5% and Fib: 68.5% and 19.8%, respectively. OP-PE could remove anti-GAD more efficiently than IA. Further, EC-PE could maintain coagulation factors such as Fib better than IA and OP-PE. It is important to select the appropriate plasmapheresis modality on the basis of the removal kinetics.