Hepatic veno-occlusive disease with severe capillary leakage after peripheral stem cell transplantation: treatment with recombinant plasminogen activator and C1-esterase inhibitor concentrate

Molecular Advances in Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease

Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) detected in the liver has been considered a severe complication of hematopoietic stem cell transplantation (HSCT). SOS/VOD is characterized by hepatomegaly, right upper quadrant pain, jaundice, and ascites. The severe forms of the disease may result in multi-organ dysfunction (MOD) with a high mortality rate (>80%). The development of SOS/VOD can be rapid and unpredictable. Therefore, early identification and severity assessment is crucial in facilitating prompt diagnosis and timely treatment. Effective treatment and potential prophylaxis with defibrotide highlight the need for characterizing a sub-group of patients at high risk for SOS/VOD. Moreover, antibodies that are conjugated with calicheamicin, gemtuzumab, and inotuzumab ozogamicin, have led to renewed interest in this syndrome. Evaluation and management of serious adverse events associated with gemtuzumab and inotuzumab ozogamicin are recommended. We review hepatic-, transplant- and patient-related risk factors, criteria for diagnosis and grading classification, and SOS/VOD potential biomarkers. Furthermore, we examine pathogenesis, clinical presentation, diagnostic criteria, risk factors, prophylaxis, and treatment of SOS/VOD occurring post HSCT. Moreover, we aim to provide an up-to-date summary of molecular advances in the diagnosis and management of SOS/VOD. We performed a comprehensive review of the literature and examined the recently available data, mostly using the PubMed and Medline search engines for original articles published over the last decade. In the era of precision medicine, our review provides up-to-date knowledge of genetic or sera markers for SOS/VOD with the goal of identifying a subset of high-risk patients.

A New Era in Endothelial Injury Syndromes: Toxicity of CAR-T Cells and the Role of Immunity

Immunotherapy with chimeric antigen receptor T (CAR-T cells) has been recently approved for patients with relapsed/refractory B-lymphoproliferative neoplasms. Along with great efficacy in patients with poor prognosis, CAR-T cells have been also linked with novel toxicities in a significant portion of patients. Cytokine release syndrome (CRS) and neurotoxicity present with unique clinical phenotypes that have not been previously observed. Nevertheless, they share similar characteristics with endothelial injury syndromes developing post hematopoietic cell transplantation (HCT). Evolution in complement therapeutics has attracted renewed interest in these life-threatening syndromes, primarily concerning transplant-associated thrombotic microangiopathy (TA-TMA). The immune system emerges as a key player not only mediating cytokine responses but potentially contributing to endothelial injury in CAR-T cell toxicity. The interplay between complement, endothelial dysfunction, hypercoagulability, and inflammation seems to be a common denominator in these syndromes. As the indications for CAR-T cells and patient populations expand, there in an unmet clinical need of better understanding of the pathophysiology of CAR-T cell toxicity. Therefore, this review aims to provide state-of-the-art knowledge on cellular therapies in clinical practice (indications and toxicities), endothelial injury syndromes and immunity, as well as potential therapeutic targets.

C1-inhibitor: an anti-inflammatory reagent with therapeutic potential

Excessive activation of the protein cascade systems often leads to severe inflammatory tissue destruction with potential life-threatening outcome. These include clinical disorders, such as capillary leak syndrome, septic shock, myocardial infarction and other ischaemia/reperfusion injuries, trauma, burns, multiple organ failure, as well as graft rejection. A therapeutic substitution of appropriate regulators appears to be a reasonable approach to reduce undesirable inflammatory reactions. C1-inhibitor, a multifunctional regulator of the various kinin-generating cascade systems, is frequently reduced in patients suffering from severe inflammation. C1-inhibitor concentrate has been used for decades as a substitution therapy to treat acute attacks in patients with hereditary angioedema. Studies including pathophysiologically relevant animal models now provide sufficient evidence that C1-inhibitor may also serve as an effective means to protect against inflammatory tissue injury. Promising clinical results are emerging which support C1-inhibitor as a candidate for therapy in severe inflammatory disorders. Although treatment with C1-inhibitor is regarded as safe, recent reports on possible side effects in certain clinical situations emphasise the importance of controlled clinical studies. The following review will focus on the impact of C1-inhibitor treatment on diseases, where complement contributes to the pathogenesis.

Introduction of the oncological pediatric risk of mortality score (O-PRISM) for ICU support following stem cell transplantation in children

Prognostic scoring systems based on physiological parameters have been established in order to predict the outcome of ICU patients. It has been demonstrated that the predictive value of these scores is limited in patients following hematopoietic stem cell transplantation (HSCT). Therefore, we evaluated patients from the Düsseldorf pediatric stem cell transplantation center with regard to predisposing factors and prognostic variables for ICU treatment and outcome. Between January 1989 and December 1998, 180 HSCT have been performed. The clinical, laboratory and HSCT-related parameters such as conditioning treatment, engraftment, GVHD, infections and HSCT toxicity were prospectively recorded and retrospectively analyzed. Established pediatric scoring systems (PRISM, TISS, P-TISS) were applied. Twenty-eight patients required intensive care (16 male, 12 female, median age: 10.9 years (range: 0.4 to 18.9 years), five autologous, 13 allogeneic-related and 10 unrelated transplanted patients). Ventilator-dependent respiratory failure was the most frequent cause of admission to the ICU (n = 23). Fourteen of 28 patients were discharged from ICU, and six of 28 patients achieved a long-term survival (110 to 396 weeks). At admission to the ICU, impaired cardiovascular status, high CRP levels and presence of macroscopic bleeding were each associated with fatal outcome (P < 0.05). The Pediatric Risk of Mortality (PRISM) score was not prognostically significant at the 0.05 level. Long-term survival after discharge from the ICU correlated with HSCT-related parameters such as the type of transplant and severity of GVHD (P = 0.002). By introduction of HSCT related parameters such as severity of GVHD (grade 2: 2 points; grade >2: 4 points), CRP-level (>10 mg/dl: 4 points), and presence of macroscopic bleeding (4 points) into the PRISM score a new oncological PRISM ('O-PRISM') score was established. This score significantly correlated with the risk of mortality in the ICU (P = 0.01). In conclusion, the new O-PRISM score accurately characterizes the clinical situation of children requiring ICU treatment following HSCT. It distinguishes more appropriately between success and failure of ICU treatment following HSCT than the standard prognostic scores. It needs to be evaluated in future prospective studies of critically ill children after HSCT. Bone Marrow Transplantation (2000).

Veno-occlusive disease of the liver

The success of high-dose cytoreductive strategies depends not only on antitumor activity but also on the tolerability of treatment. Although advances in supportive care have significantly reduced mortality due to infection and hemorrhage, regimen-related toxicities remain problematic. Hepatic veno-occlusive disease (VOD) is the most serious regimen-related toxicity after high-dose cytoreductive therapy. Risk factors for VOD are well established, but the biology of the syndrome remains poorly understood. Unfortunately, no pharmacologic approaches that clearly prevent or treat VOD have been identified. A better understanding of the pathogenesis of VOD will lead to more effective prevention and treatment strategies.