Effectiveness of therapeutic plasma exchange in a critically ill child with secondary hemophagocytic lymphohistiocytosis

PD-1 Blockader-associated Atypical Hemophagocytic Lymphohistiocytosis: A Cautionary Case Report

Hemophagocytic lymphohistiocytosis (HLH) is a fatal immune hyperactivity syndrome with high mortality. It seriously endangers human health. HLH associated with immune checkpoint inhibitors is rare, and no particular diagnostic guidelines or treatment regimens exist. A 36-year-old patient with metastatic right atrial angiosarcoma was treated with programmed cell death-1 (PD-1) blockader toripalimab and pazopanib, a vascular endothelial growth factor receptor blockader. However, the patient presented to our center with HLH, and he accepted combination therapy of therapeutic plasma exchange (TPE) and immunotherapy. The patient improved quickly, after only one TPE procedure. Finally, he was discharged after completing two TPE procedures. We summarize a case of PD-1 blocker associated atypical HLH that was successfully treated with TPE. Further evidence is needed to elucidate whether TPE has therapeutic potential for immunotherapy associated HLH.

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.

Role of therapeutic plasma exchange in the management of COVID-19-induced cytokine storm syndrome

The risk of mortality in patients with coronavirus disease 2019 (COVID-19) is largely related to an excessive immune response, resulting in a hyperinflammatory and hypercoagulable condition collectively referred to as cytokine storm syndrome (CSS). Management of critically ill patients with COVID-19 has included attempts to abate this process, prevent disease progression, and reduce mortality. In this context, therapeutic plasma exchange (TPE) offers an approach to eliminate inflammatory factors and cytokines, offset the pathologic coagulopathy, and reduce the CSS effects. The aim of this review is to analyze available data on the use of TPE for the treatment of CSS in patients with COVID-19. Systematic searches of PubMed, Scopus and COVID-19 Research were conducted to identify articles published between March 1, 2020 and May 26, 2021 reporting the use of TPE for the treatment of COVID-19-induced CSS. A total of 34 peer-reviewed articles (1 randomized controlled trial, 4 matched case-control series, 15 single-group case series, and 14 case reports), including 267 patients, were selected. Despite the low evidence level of the available data, TPE appeared to be a safe intervention for critically ill patients with COVID-19-induced CSS. Although inconsistencies exist between studies, they showed a general trend for decreased interleukin-6, C-reactive protein, ferritin, D-dimer, and fibrinogen levels and increased lymphocyte counts following TPE, supporting the immunomodulatory effect of this treatment. Moreover, TPE was associated with improvements in clinical outcomes in critically ill patients with COVID-19. While TPE may offer a valuable option to treat patients with COVID-19-induced CSS, high-quality randomized controlled clinical trials are needed to confirm its potential clinical benefits, feasibility, and safety. Moreover, clear criteria should be established to identify patients with CSS who might benefit from TPE.

Accuracy of the criteria for hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis, also known as a hemophagocytic syndrome, is a life-threatening condition that can develop in critically ill patients with malignancies, severe infections, during chemotherapy, and may be associated with currently known or unknown genetic abnormalities; however, this list of potential causes can be extensive. The purpose of this study is to draw attention to the accuracy of its diagnostic criteria, association with a variety of clinical conditions, pathophysiological mechanisms, and outcomes of the diseases. From the medical records in our hospital, we retrospectively extracted 13 cases with hemophagocytosis over a 10-year period. Subsequently, we thoroughly analyzed medical records for the criteria used, the time required for making a diagnosis, adequacy of the criteria, management, and outcomes. We found that not all criteria were used for diagnosis, and the most sensitive and specific tests (genetic study, ferritin, and soluble IL-2r levels) were sometimes bypassed. Late diagnosis delayed management of some patients. Only a few treatment options were used for patient care. The hemophagocytic syndrome is a very rare and fatal entity requiring highly sensitive and specific diagnostic criteria for prompt diagnosis, targeted management, and thorough follow-up. Every patient admitted to the hospital with life-threatening conditions should be suspected and tested for the hemophagocytic syndrome as early as possible. The criteria for hemophagocytic lymphohistiocytosis should be revised, with the most sensitive and specific ones being done in all cases. Subsequently, each patient should be tested for the presence of genetic abnormalities that correlate with the syndrome.