Use of extracorporeal immunomodulation in a toddler with hemophagocytic lymphohistiocytosis and multisystem organ failure

Immunomodulatory effects of a cell processing device to ameliorate dysregulated hyperinflammatory disease states

Cell directed therapy is an evolving therapeutic approach to treat organ dysfunction arising from hyperinflammation and cytokine storm by processing immune cells in an extracorporeal circuit. To investigate the mechanism of action of the Selective Cytopheretic Device (SCD), in vitro blood circuits were utilized to interrogate several aspects of the immunomodulatory therapy. SCD immunomodulatory activity is due to its effects on circulating neutrophils and monocytes in a low ionized calcium (iCa, Ca2+) blood circuit. Activated neutrophils adhere to the SCD fibers and degranulate with release of the constituents of their exocytotic vesicles. Adhered neutrophils in the low iCa environment display characteristics of apoptotic senescence. These neutrophils are subsequently released and returned back to circulation, demonstrating a clear potential for in vivo feedback. For monocytes, SCD treatment results in the selective adhesion of more pro-inflammatory subsets of the circulating monocyte pool, as demonstrated by both cell surface markers and cytokine secretory rates. Once bound, over time a subset of monocytes are released from the membrane with a less inflammatory functional phenotype. Similar methods to interrogate mechanism in vitro have been used to preliminarily confirm comparable findings in vivo. Therefore, the progressive amelioration of circulating leukocyte activation and immunomodulation of excessive inflammation observed in SCD clinical trials to date is likely due to this continuous autologous leukocyte processing.

Increasing Eligibility to Transplant Through the Selective Cytopheretic Device: A Review of Case Reports Across Multiple Clinical Conditions

A stable, minimum physiological health status is required for patients to qualify for transplant or artificial organ support eligibility to ensure the recipient has enough reserve to survive the perioperative transplant period. Herein, we present a novel strategy to stabilize and improve patient clinical status through extracorporeal immunomodulation of systemic hyperinflammation with impact on multiple organ systems to increase eligibility and feasibility for transplant/device implantation. This involves treatment with the selective cytopheretic device (SCD), a cell-directed extracorporeal therapy shown to adhere and immunomodulate activated neutrophils and monocytes toward resolution of systemic inflammation. In this overview, we describe a case series of successful transition of pediatric and adult patients with multiorgan failure to successful transplant/device implantation procedures by treatment with the SCD in the following clinical situations: pediatric hemophagocytic lymphohistiocytosis, and adult hepatorenal and cardiorenal syndromes. Application of the SCD in these cases may represent a novel paradigm in increasing clinical eligibility of patients to successful transplant outcomes.

Selective Cytopheretic Device Use in Continuous Kidney Replacement Therapy in Children: A Cohort Study With a Historical Comparator

Rationale and Objective

Critically ill children with acute kidney injury (AKI) requiring continuous renal replacement therapy (CRRT) are at increased risk of death. The selective cytopheretic device (SCD) promotes an immunomodulatory effect at circuit-ionized calcium of <0.40 mmol/L. In an adult CRRT patient study, SCD-treated patients reported improved survival or dialysis independence. We reported safety data from children who received CRRT-SCD therapy and compared outcomes with a historic pediatric CRRT cohort.

Study Design

We performed 2 prospective multicenter studies to evaluate the safety and feasibility of SCD in critically ill children.

Setting and Participants

Four pediatric institutions enrolled children weighing 10 kg or more with AKI and multi-organ dysfunction receiving CRRT as the standard of care with the SCD-integrated post-CRRT membrane.

Exposure

Patients received CRRT-SCD with regional citrate anticoagulation for up to 7-10 days, or CRRT discontinuation, whichever came first.

Analytical Approach

We reported serious adverse events among patients and CRRT-SCD-related process and outcome variables. We compared survival to intensive care unit (ICU) discharge rates between the CRRT-SCD cohort and a matched cohort from the prospective pediatric CRRT registry, using odds ratios in multivariable analysis for factors associated with prospective pediatric CRRT patient ICU mortality. To validate these crude analyses, Bayesian logistic regression was performed to assess for attributable benefit-risk assessment of the SCD.

Results

Twenty-two patients received CRRT-SCD treatments. Fifteen serious adverse events were recorded; none were SCD-related. Seventeen patients survived till ICU discharge or day 60. Both multivariable and Bayesian analyses revealed a probable benefit of the addition of SCD. Fourteen of the 16 patients surviving ICU discharge reported a normal estimated glomerular filtration rate and no patient was dialysis dependent at 60 days.

Limitations

The study had a few limitations, such as (1) a small sample size in the SCD-PED cohort group; (2) unchanging historic control group; and (3) adverse events were not recorded in the control group.

Conclusions

The SCD therapy is feasible, safe, and demonstrates probable benefit for critically ill children who require CRRT for AKI.

Extracorporeal Immunomodulation Therapy in Acute Chronic Liver Failure With Multiorgan Failure: First in Human Use

Two patients presented with acute on chronic liver failure and multiorgan failure and, as typical for this disorder, they presented with hyperinflammation and anticipated high mortality rates. Both cases were diagnosed with hepatorenal syndrome (HRS). Under a FDA approved Investigational Device Exemption clinical trial, they underwent treatment with an extracorporeal cell-directed immunomodulatory device, called selective cytopheretic device. Both patients showed rapid clinical improvement associated with a decline in elevated blood cytokine concentrations and diminution of activation levels of circulating leukocytes. On follow-up, one patient was alive at day 90 after treatment and undergoing liver transplantation evaluation and the other patient had a successful liver transplantation 6 days after selective cytopheretic device therapy ended. These cases represent the first in human evaluation of extracorporeal cell-directed immunomodulation therapy in acute on chronic liver failure with successful clinical outcomes in a disorder with dismal prognosis.

Hemolytic Uremic Syndrome-Induced Acute Kidney Injury Treated via Immunomodulation with the Selective Cytopheretic Device

INTRODUCTION

Shiga-toxin associated-hemolytic uremic syndrome (STEC-HUS) is a severe cause of acute kidney injury (AKI) in children. Although most children recover, about 5% die and 30% develop chronic renal morbidity. HUS pathophysiology includes activated neutrophils damaging vascular endothelial cells. Therapeutic immunomodulation of activated neutrophils may alter the progression of disease. We present 3 pediatric patients treated with the selective cytopheretic device (SCD).

METHODS

We describe a 12 y.o. (patient 1) and two 2 y.o. twins (patients 2 and 3) with STEC-HUS requiring continuous renal replacement therapy (CRRT) who were enrolled in two separate studies of the SCD.

RESULTS

Patient 1 presented with STEC-HUS causing AKI and multisystem organ failure and received 7 days of SCD and CRRT treatment. After SCD initiation, the patient had gradual recovery of multi-organ dysfunction, with normal kidney and hematologic parameters at 60-day follow-up. Patients 2 and 3 presented with STEC-HUS with AKI requiring dialysis. Each received 24 h of SCD therapy. Thereafter, both gradually improved, with normalization (patient 2) and near-normalization (patient 3) of kidney function at 60-day follow-up.

CONCLUSION

Immunomodulatory treatment with the SCD was associated with improvements in multisystem stigmata of STEC-HUS-induced AKI and was well-tolerated without any device-related adverse events.