Regional citrate anticoagulation vs systemic heparin anticoagulation for double-filtration plasmapheresis

INTRODUCTION

Double-filtration plasmapheresis (DFPP) has been utilized for immunomodulation in kidney transplantation. Anticoagulation is important to maintain circuit patency during DFPP. We aimed to compare the efficacy and safety of regional citrate anticoagulation (RCA) with systemic heparin anticoagulation during DFPP in kidney transplant recipients.

METHODS

A retrospective cohort study was conducted to compare the efficacy and safety of RCA (RCA-DFPP) to systemic heparin anticoagulation (Hep-DFPP) for DFPP among kidney transplant recipients in a single tertiary center.

RESULTS

A total of 112 sessions of DFPP were performed for 23 subjects, of which 62 sessions were RCA-DFPP and 50 sessions were Hep-DFPP. There were 13 sessions (11.6%) of premature circuit clotting, 10 sessions (16.1%) for RCA-DFPP and 3 sessions (6.0%) for Hep-DFPP (P = .10). All premature circuit clotting episodes occurred in subjects who underwent DFPP through a vascular catheter. Premature circuit clotting was associated with the use of a vascular catheter (odds ratio [OR] 14.2, 95% confidence interval [CI] 2.7-73.7; P < .01) and high postfilter ionized calcium (OR 12.7, 95% CI 1.4-112.5; P < .01). There was no major bleeding event. Hep-DFPP was associated with higher occurrence of hypocalcemia (OR 1.1, 95% CI 1.0-1.2; P < .01) and metabolic acidosis (OR 1.4, 95% CI 1.2-2.0; P = .04), while hypomagnesemia was more common for RCA-DFPP (OR 2.9, 95% CI 1.1-7.4; P = .03).

CONCLUSION

Amongst kidney transplant patients who receive DFPP therapy, RCA-DFPP may be comparable to Hep-DFPP for the maintenance of circuit patency. Functioning vascular access is vital in avoiding premature clotting of the circuit. Close monitoring of electrolyte imbalances and coagulopathy related to DFPP is recommended.

State of the Evidence: Drug Removal via Apheresis

Therapeutic apheresis refers to a diversity of procedures in which specific hematologic components (e.g., plasma, erythrocytes, leukocytes, etc.) with pathological associations are removed from circulation (with possible replacement) in order to treat a variety of disease processes. As pharmacologic agents also circulate with these components, their removal is sometimes incidental, or in the scenario of drug toxicity, a therapeutic goal. The corpus of published manuscripts on this subject has grown immensely over the past few decades; however, the breadth of diseases, methods, and drugs that co-exist in this space make it challenging to generate generalizable evidence regarding drug removal via apheresis. This review discusses factors worth considering when interpreting literature-reported data on drug removal by apheresis with examples from several notable studies and highlights topics in need of evidential improvement and growth as our palette of therapeutic agents continues to expand.

Hemostatic effects of therapeutic plasma exchange: A concise review

Therapeutic plasma exchange (TPE) alters the hemostatic balance. Contributing to TPE's hemostatic effects is the mechanical processing of blood in the extracorporeal circuit, circuit anticoagulant, type of replacement fluid, TPE schedule and number of procedures, TPE timing relative to invasive procedures, and removal of nontargeted components such as platelets, coagulation proteins, and cytokines. Although TPE's hemostatic effects are well established, how it impacts the bleeding risk is not clearly understood. In this concise review, we describe the effects of the above TPE-related factors on hemostatic balance, present data on the effects of TPE on blood hemostasis, including its effects on platelet counts and clotting assays, and review the literature on the impact of TPE-induced hemostatic changes on TPE-associated bleeding events. Finally, we discuss risk factors associated with bleeding during TPE and review the literature on TPE-associated hemostatic effects in the pediatric population.

Bleeding outcomes of inpatients receiving therapeutic plasma exchange: A propensity-matched analysis of the National Inpatient Sample

BACKGROUND

Although therapeutic plasma exchange (TPE) is associated with hemostatic abnormalities, its impact on bleeding outcomes is unknown. Therefore, the main study objective was to determine bleeding outcomes of inpatients treated with TPE.

STUDY DESIGN AND METHODS

In a cross-sectional analysis of the National Inpatient Sample (NIS), discharges were identified with 10 common TPE-treated conditions. A 1:3 propensity-matched analysis of TPE- to non-TPE-treated discharges was performed. The primary outcome was major bleeding and secondary outcomes were packed red blood cell (PRBC) transfusion, mortality, disposition, hospital length of stay (LOS), and charges. Multivariable regression analyses were used to examine the association between TPE and study outcomes.

RESULTS

The study population was 15,964 discharges, of which 3991 were TPE- treated. The prevalence of major bleeding was low (5.4%). When compared to non-TPE discharges, TPE had a significant and positive association with major bleeding (OR = 1.37, 95% CI: 1.16-1.63, p = .0003). TPE was also associated with PRBC transfusion (OR = 1.66, 95% CI: 1.42-1.94, p < .0001), in-hospital mortality (OR = 1.45, 95% CI: 1.10-1.90, p = .0008), hospital length of stay (12.45 [95% CI: 11.95-12.97] vs. 7.38 [95% CI: 7.12-7.65] days, p < .0001) and total charges, ($125,123 [95% CI: $119,220-$131,317] vs. $61,953 [95% CI: $59,391-$64,625], p < .0001), and disposition to non-self-care (OR = 1.29, 95% CI: 1.19-1.39, p < .0001).

DISCUSSION

The use of TPE in the inpatient setting is positively associated with bleeding; however, with low prevalence. Future studies should address risk factors that predispose patients to TPE-associated bleeding.

Enoxaparin-induced Wunderlich syndrome in a young patient with anti-GAD 65-associated opsoclonus and limbic encephalitis: a rare complication in a rare disease

Wunderlich syndrome is a rare condition characterised by acute spontaneous non-traumatic renal haemorrhage into the subcapsular and perirenal spaces. Our case of anti-GAD65-associated autoimmune encephalitis (AE), aged 30 years, developed this complication following use of enoxaparin and was managed by selective glue embolisation of subsegmental branches of right renal cortical arteries. Our case had opsoclonus as one of the clinical manifestations, which has till now been described in only two patients of this AE. This patient received all forms of induction therapies (steroids, plasmapheresis, intravenous immunoglobulin and rituximab) following which she had good improvement in her clinical condition. The good response to immunotherapy is also a point of discussion as this has been rarely associated with anti-GAD65 AE.

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.

Optimizing management of replacement fluids for therapeutic plasma exchange: Use of an automated mathematical model to predict post-procedure fibrinogen and antithrombin levels in high-risk patients

BACKGROUND

Therapeutic plasma exchange (TPE) utilizes an extracorporeal circuit to remove pathologic proteins causing serious illness. When processing a patient's entire blood volume through an extracorporeal circuit, proteins responsible for maintaining hemostatic system homeostasis can reach critically low levels if replacement fluid types and volumes are not carefully titrated, which may increase complications.

METHODS

The charts from 27 patients undergoing 46 TPE procedures were reviewed to evaluate the accuracy of our predictive mathematical model, utilizing the following patient information: weight, hematocrit, pre- and post-TPE factor levels (fibrinogen, n = 46, and antithrombin, n = 23), process volume and volumes of fluids (eg, plasma, albumin, and normal saline) administered during TPE and adverse events during and after TPE.

RESULTS

Altogether, 25% of patients experienced minor adverse events that resolved spontaneously or with management. There were no bleeding or thrombotic complications. The mean difference between predicted and measured post-TPE fibrinogen concentrations was -0.29 mg/dL (SD ±23.0, range -59 to 37), while percent difference between measured and predicted fibrinogen concentration was 0.94% (SD ±10.8, range of -22 to 19). The mean difference between predicted and measured post-TPE antithrombin concentrations were 0.89% activity (SD ±10.0, range -23 to 14), while mean percent difference between predicted and measured antithrombin concentrations was 3.87% (SD ±14.5, range -25 to 38).

CONCLUSIONS

Our model reliably predicts post-TPE fibrinogen and antithrombin concentrations, and may help optimize patient management and attenuate complications.

Effects of therapeutic plasma exchange on anticoagulants in patients receiving therapeutic anticoagulation: a systematic review

Therapeutic plasma exchange (TPE) removes coagulation proteins, but its impact on therapeutic anticoagulation is unknown. We performed a systematic review of the literature to determine the coagulation effects of TPE in patients receiving systemic anticoagulation. We searched MEDLINE, CINAHL, EMBASE, and Web of Science until June 2018 for studies combining controlled vocabulary and keywords related to therapeutic plasma exchange, plasmapheresis, anticoagulants, and therapy. The primary outcome was the effect of TPE on anti-Xa activity, activated partial thromboplastin time (aPTT), or international normalized ratio (INR). The secondary outcome was reports of post-TPE bleeding or thrombosis. A total of 1830 references were screened and eight studies identified. Our selected studies (five case reports and three case series) involved 23 patients and evaluated the effects of seven anticoagulants. Six studies of unfractionated heparin, low-molecular-weight heparins, and direct oral anticoagulants demonstrated an anti-Xa level decline. Two studies of unfractionated heparin and low-molecular-weight heparins showed an aPTT increase. One study of warfarin showed a post-TPE INR increase. Reports of post-TPE bleeding occurred in two patients and thrombosis in one. In patients receiving therapeutic anticoagulation, TPE is associated with anti-Xa activity decline and aPTT and INR increase. These coagulation changes do not appear to significantly increase bleeding or thrombotic risk. Our data suggest the need for prospective studies to investigate the true clinical impact of TPE on therapeutic anticoagulation.