Pediatric Therapeutic Apheresis: A Critical Appraisal of Evidence

Therapeutic plasma exchange for multiorgan dysfunction among critically ill pediatric patients with leukemia: A single-institutional experience

INTRODUCTION

Therapeutic plasma exchange (TPE) has well-documented applications in the adult population, outlined by the American Society for Apheresis (ASFA) 2019 guidelines. Limited data exist regarding the use of TPE in critically ill pediatric patients; however, these reports rarely include patients with oncological diseases.

METHODS

We highlight the use of TPE in the acute management of seven pediatric patients with leukemia treated at Children's Mercy Hospital ICU from 2015 to 2020, including TPE specifications, baseline and interval laboratory evaluation, and outcome measures. Analysis compared those who did (n = 4) and did not (n = 3) survive 30 days post-TPE.

RESULTS

Multiorgan failure (MOF) prompted the initiation of TPE in 85.7% of patients, 57.1% of whom were also diagnosed with hemophagocytic lymphohistiocytosis (HLH). Baseline laboratory evaluations prior to initiation of TPE were similar between the two groups. With subsequent TPE treatments, C-reactive protein (CRP) and lactic acid decreased. CRP and lactic acid following the last TPE treatment were significantly higher for those deceased 30 days post-TPE (P = .023 and .031, respectively). No TPE-associated adverse events necessitated discontinuation of TPE treatment. Several surviving patients required chemotherapy dose reductions or alterations.

CONCLUSION

Our cohort demonstrated MOF and HLH consistently as indications for TPE, currently ASFA category III indications (optimal role of apheresis is not yet established). Recognition of this treatment modality earlier in the clinical course for critically ill oncological patients may lead to the development of formal protocols that may result in earlier initiation of TPE and improved outcomes.

Retrospective analysis comparing complication rates of centrifuge vs membrane-based therapeutic plasma exchange in the pediatric population

BACKGROUND

There are two conventional modalities used to perform therapeutic plasma exchange (TPE): centrifuge TPE (cTPE) or membrane TPE (mTPE). There is limited data on complications with mTPE.

OBJECTIVE

We sought to better understand the patient and machine complications of mTPE compared to cTPE. We hypothesize that our protocol for mTPE using heparin anticoagulation is well-tolerated.

METHODS

In this retrospective cohort study of children <21 years of age, we evaluated differences in patient and machine characteristics and complications between cTPE (with citrate anticoagulation) vs mTPE (with heparin anticoagulation).

RESULTS

Of the 105 patients who met inclusion/exclusion criteria, 63 received cTPE and 42 mTPE via Prismaflex. Those who used mTPE were younger (4.8 ± 2.8 years vs 15.2 ± 3.7 years, P = .0001) and weighed less (19.5 ± 10.6 vs 71.7 ± 28.5 kg, P = .0001). There were no significant differences in patient-related complications or indications for TPE between the two modalities. Of the 1031 therapies performed,1003 therapies were analyzed (646 using cTPE and 357 using mTPE) due to exclusion criteria. No significant difference in patient complications were detected between groups. Machine-related complications were infrequent in both approaches. More circuits clotted during mTPE than during cTPE (6.7% [24/357] vs 0% [0/646]; P < 0.001).

CONCLUSION

Although we use mTPE in smaller children, we showed low rates of complications that were not statistically different from cTPE performed in older children. While the overall rate of circuit clotting using mTPE was low, it occurred more commonly than with cTPE.

Therapeutic plasma exchange for life-threatening pediatric disorders

INTRODUCTION

Therapeutic plasma exchange (TPE) is acknowledged to be an effective treatment in life-threatening pediatric disorders. Apheresis for pediatric diseases has been poorly investigated, and most studies to date featured small numbers of patients and lacked control groups. The objective of the present study was to evaluate the tolerance of TPE in pediatric patients.

MATERIALS AND METHODS

A retrospective cohort study via a web-based electronic case report form including pediatric patients referred for TPE between January 2005 and December 2014.

RESULTS

A total of 78 patients (median [range] age: 9.8 [0.53-17.93]) and 731 TPE procedures were analyzed. The indications were antibody-mediated rejection (n = 33; 42%) and desensitization therapy (n = 5; 6%) after solid organ or hematopoietic stem cell transplantation, thrombotic microangiopathy (n = 17; 22%), pediatric inflammatory diseases (n = 16; 21%), kidney diseases (n = 6; 8%), and hyperviscosity syndrome (n = 1; 1%). On average, each patient underwent six procedures during the first session [range: 1-19]. In the 2 weeks following the start of a session, 72 patients (92%) presented a total of 311 adverse events (AEs) potentially related to TPE. The risk of AEs was not related to the indication for TPE, the intensity of care, venous access, plasma substitute use, or body weight. None of the deaths was related to the TPE.

CONCLUSION

We studied one of the largest retrospective pediatric cohorts described to date. Our experience of TPE children's TPE feasibility concerned specific, life-threatening conditions and otherwise treatment-refractory diseases.

Centrifugal Therapeutic Plasma Exchange in Pediatric Patients

OBJECTIVE

To assess the safety of centrifugal therapeutic plasma exchange (TPE) in pediatric patients.

METHODS

The authors did a retrospective analysis of all TPE procedures performed in pediatric patients over a period of 19 y (2001-2019). Procedures were done on different apheretic devices, daily or on alternate days depending on the clinical condition of the patient. Adverse events during the procedure were noted and analyzed.

RESULTS

A total of 672 TPE (with mean of 6.77 ± 4.85) procedures were performed for 99 pediatric patients with different indications like hematological (n = 68), renal (n = 12), neurology (n = 18) and hepatology (n = 1). The mean age was 7.00 ± 3.11 y and weight was 20.72 ± 9.17 kg. Adverse events (AEs) were observed during 34 (5%) procedures, most common were allergic reactions to replacement fluid (2.24%) followed by hypotension (1.04%), symptomatic hypocalcemia (1.04%), line occlusion (0.59%), and febrile non hemolytic transfusion reaction (0.41%). A significant correlation of AEs was observed with weight (p = 0.045), total blood volume of the patient (p = 0.04), increasing number of procedures (p = 0.000) and replacement fluid [Fresh frozen plasma (FFP)] (p = 0.04). All AEs were managed as per departmental standard operating procedures (SOPs) completing procedures successfully except one which was abandoned. No mortality was observed during the procedures.

CONCLUSION

TPE is a safe therapeutic modality in pediatric patients when performed under expert technical supervision with proper SOPs in place.

Novel use of a midline catheter for therapeutic and donor apheresis in children and adults

BACKGROUND

Apheresis procedures require adequate vascular access to achieve optimal inlet flow rates. While central lines provide such access, their placement and use are associated with risks; some of these risks are minimized if peripheral intravenous access can be established. However, peripheral intravenous access is associated with challenges in the pediatric setting. Research indicates that midline catheters reduce the use of CVADs and their associated risks. The use of midline catheters for apheresis has been reported recently in adults, but no studies have been published on their use in children. Thus, the purpose of this study was to evaluate the use of midline catheters for apheresis in the pediatric setting.

METHODS

A retrospective observational study was conducted to evaluate the safety and efficacy of midline catheters in subjects who underwent apheresis at a pediatric hospital from April 2018 to August 2020. Demographic data, clinical data (diagnosis, procedure, catheter size, body mass), and outcome data (inlet flow rate, total blood volume [TBV] processed, procedure time, and cell counts) were collected.

RESULTS

Eighteen subjects received a total of 100 midline catheters for 73 apheresis procedures. Inlet flow rates ranged from 45 to 80 mL/min, TBV ranged from 2872 to 20 000 mL, and procedure time ranged from 1.25 to 7 hours. Inlet flow rates met or exceeded the recommended inlet flow rates for apheresis in children and adults (P < .0001). No adverse events occurred.

CONCLUSION

Midline catheters provide safe and effective vascular access for apheresis. Future research should include younger patients with lower body mass.

Use of therapeutic plasma exchange for pediatric neurological diseases

Therapeutic plasma exchange is used to treat neurological diseases in the pediatric population. Since its first use in pediatric patients with hepatic coma in the form of manual whole blood exchange, therapeutic plasma exchange has been increasingly used to treat these disorders of the nervous system. This expansion is a result of improved techniques and apheresis instruments suitable for small children, as well as the recognition of its applicability to many diseases in the pediatric population. This review provides a historical overview of the use of therapeutic apheresis in children and highlights the most common applications for therapeutic plasma exchange to treat neurological disorders in children.

Successful Stem Cell Apheresis Using Spectra Optia in a 6 kg Child With Atypical Teratoid/Rhabdoid Tumor

Peripheral blood stem cell apheresis has become a routine procedure for the collection of peripheral blood stem cells to enable high-dose chemotherapy followed by autologous stem cell transplantation in high-risk pediatric malignancies. However, the procedure remains challenging in very low-weight infants due to high extracorporeal blood volume and citrate toxicity. Our case report demonstrates in detail a successful and complication-free large-volume leukapheresis in a very small infant weighing 6 kg using a Spectra Optia apheresis system after placing a femoral double-lumen Shaldon catheter. Anticoagulation was achieved by citrate dextrose solution without the use of heparin. The total amount of blood being processed during the procedure equaled almost 4 times the total blood volume of the patient. The final apheresis product contained 14.0×10 CD34 cells/kg body weight. The infant was diagnosed with an atypical teratoid/rhabdoid tumor of the thalamus and third ventricle at the age of 3 months and had a history of epileptic seizures.

Complications of therapeutic plasma exchange: A retrospective study of 1201 procedures in 435 children

Therapeutic plasma exchange (TPE) is now widely used in therapy of multiple diseases in children, by removing the plasma with pathogenic agents from patients. However, adverse reactions may limit its application.A retrospective cohort study of 435 hospitalized children treated with 1201 plasma exchange procedures between January 2013 and July 2018 were enrolled.Complications occurred in 152 procedures (12.7%); 90 procedures (7.5%) had ≥2 complications. No death occurred. The most common complications were pruritus and urticaria (7%), followed by hypertension (1.92%) and hypotension (1.17%). One child had an outbreak of disseminated cryptococcosis neoformans infection, another child developed anaphylactic shock, and 3 children presented toxic epidermal necrolysis after TPE. The incidence of pruritus and urticaria was higher in children of the 6∼15 year group (P < .05) compared with other age groups. There was no significant difference in the incidence of hypertension and hypotension in children at different ages and weights (P > .05). Compared with other diseases, anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis led to a higher incidence of complications in children (P < .05).The results suggest that TPE is a relatively safe procedure for children, and most of the complications are mild. The most common complication is pruritus and urticaria. However, serious complications such as toxic epidermal necrolysis and infection should still be taken seriously.

Prognostic indicators of improvement with therapeutic plasma exchange in pediatric demyelination

OBJECTIVES

To determine the safety and clinical benefit of therapeutic plasma exchange (TPE) as rescue therapy in children with acute inflammatory demyelinating CNS syndromes and to identify baseline prognostic indicators of treatment improvement.

METHODS

This single-center retrospective pediatric cohort included all consecutive patients admitted to our hospital over the period from 2003 to 2017 because of a steroid-refractory acute CNS event presumed to be inflammatory who required TPE. Functional status assessment to identify improvement included the following performance category scales: visual outcome, bladder control, gait, and Expanded Disability Status Scale (EDSS). These assessments were performed before and after TPE in every patient.

RESULTS

Sixty-five children requiring TPE to treat 78 CNS attacks were included for analysis. Median age at TPE was 10.5 years (1.9-18 years); 45% were girls. Seropositivity (aquaporin-4 water channel-immunoglobulin G [IgG] or myelin oligodendrocyte glycoprotein-IgG) was found in 20 of 42 (48%) patients. Attack phenotypes leading to TPE were optic neuritis (ON) in 42%, longitudinally extensive transverse myelitis (LETM) in 31%, ON + LETM in 15%, and other combined syndromes in 11%. Overall, moderate to marked neurologic improvement was observed in 72% of children at the end of TPE and in 88.5% at 6 months of follow-up. Lower baseline scores on the EDSS, visual outcome, and gait scales were found to be independent prognostic indicators of treatment benefit. Sex, age at onset and at TPE, attack phenotype, disease duration, and time from attack onset to TPE initiation were not significantly associated with treatment outcome. Adverse events were observed in 31 of 524 (5.9%) procedures, being severe in 4.

CONCLUSIONS

TPE was an effective rescue therapy associated with functional improvement. No therapeutic window for TPE initiation was identified in this pediatric cohort. Overall frequency of adverse events was low; however, serious events should be anticipated and avoided.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that for children with acute inflammatory demyelinating CNS syndromes, TPE leads to functional improvement.

Development of apheresis techniques and equipment designed for patients weighing less than 10 kg

The procedure of apheresis in pediatric patients, particularly in those with low weight (body weight<10 kg) presents an important challenge due to particularities of this group. There are no specific guidelines or enough scientific evidence to standardize the practice in this group of patients. In addition to the psychological aspect, the correct calculation of the total blood volume, the extracorporeal volume of the cell separator and an estimated decrease in hematocrit must be considered. Personalized protocols for priming of the apheresis equipment, sufficient blood flow and adequate anticoagulation are essential for patient comfort and therapeutic success. The purpose of this article is to present the results of the national study of apheresis practices in low weight group of children conducted from 2012 to 2018. Protocols and patients' data collected from various apheresis centers in Argentina were compared with the apheresis protocols around the world. Our protocols and data were similar to those in other countries; however, no detailed and specific guidelines for apheresis practices in this population of patients with unique requirements have been developed to date.

Epidemiology of therapeutic apheresis with a multidisciplinary approach at a high volume pediatric center

INTRODUCTION

Therapeutic apheresis (TA) is used inconsistently in pediatric populations. We seek to define our multidisciplinary institutional practice.

METHODS

We conducted a retrospective chart review of patients receiving TA from January 1, 2012 through October 31, 2015. Data collected included demographics, American Society of Apheresis (ASFA) indication, complications, and mortality.

RESULTS

Over 46 months, 1198 TA procedures were conducted on 289 patients ranging in age from 5 months to 21 years with weights ranging from 4.76 to 170.3 kg (16 procedures in patients <10 kg). The procedures were 86% therapeutic plasma exchange, 10% red blood cell exchange, 4% extracorporeal photopheresis, and 5 leukocytapheresis procedures. TA was initiated in different clinical environments: 41% outpatient, 37% intensive care, 15% general inpatient, and 7% operating room. The ASFA category (6th edition) indications for the 1198 procedures included: 44% category I, 25% category II, 23% category III, a single category IV procedure, and the remainder (8%) uncategorized by ASFA. The rate of procedure failure and procedure-related mortality are 1 and 0%, respectively. Case mortality rate was 4%.

CONCLUSION

At a large volume pediatric hospital, TA is commonly used and can be performed safely in a variety of settings by a multidisciplinary team. This demographic review catalogs the number and type of procedures performed as a second-line therapy or on the basis of limited evidence. Additional collaborative investigation is needed to evaluate unique implications of TA in pediatrics to maximize efficacy while preserving safety.