Severe Hepatic Sinusoidal Obstruction Syndrome in a Child Receiving Vincristine, Actinomycin-D, and Cyclophosphamide for Rhabdomyosarcoma: Successful Treatment with Defibrotide

Drug-induced hepatic sinusoidal obstruction syndrome: current advances and future perspectives

Hepatic sinusoidal obstruction syndrome (HSOS) has gained recognition as a rare form of drug-induced liver injury (DILI) in recent years. Although extensively studied in the context of hematopoietic stem cell transplantation (HSCT), the applicability of this knowledge to drug-induced HSOS remains limited due to distinct etiological factors. The primary causes of drug-induced HSOS include the ingestion of pyrrolizidine alkaloid (PA)-containing plants, as well as the use of chemotherapeutic agents and immunosuppressive drugs. The underlying pathogenesis is not yet fully understood. Noninvasive diagnostic imaging modalities such as ultrasonography, computed tomography, and magnetic resonance imaging play a valuable role in diagnosis. Further research is essential to develop standardized severity grading systems and optimize treatment strategies. This review summarizes the key etiologies, pathological mechanisms, clinical features, diagnostic approaches, severity assessment, and therapeutic options for drug-induced HSOS.

Indispensable role of microbes in anticancer drugs and discovery trends

Recent years have seen an increased focus on the advancement of naturally derived products for the treatment of cancer. Since the beginning of recorded history, nature has provided a variety of medicinal agents, and an overwhelming number of drugs that we have today are derived from natural sources. Such natural agents are prominently used to treat several diseases such as diabetes, malaria, Alzheimer's, pulmonary disorders, etc. with cancer being the highlight of this review. Due to the rapid development of resistance to chemotherapeutic drugs, the hunt for effective novel drugs is still a paramount concern in cancer treatment. Moreover, many chemotherapy drugs typically have high toxicity and adverse side effects, which necessitates the need to develop anti-tumor drugs that can be employed to treat deadly tumors with fewer negative effects on health and better efficacy. Isolation of several chemotherapeutic drugs has been conducted from a wide range of natural sources which include plants, microbes, fungi, and marine microorganisms. Considering the trends of previous decades, microbial diversity has grown to play a significant role in the formulation of pharmaceuticals and drugs, especially antibiotics and anti-cancer medications. Microbe-derived antitumor antibiotics such as anthracycline, epothilones, bleomycin, actinomycin, and staurosporine are amongst the widely used cancer chemotherapeutic agents. This review deals majorly with microbe-derived anticancer drugs taking into account their derivatives, mechanism of action, isolation procedures, limitations, and tumors targeted by them. This article also reports the phase of clinical study these drugs are undergoing. Moreover, it intends to portray the indispensable part that these microbes have been playing since time immemorial in the odyssey of chemotherapeutic agents. KEY POINTS: • Microbial diversity contributes heavily towards the formulation of anticancer drugs. • Polypeptides, carbohydrates, and alkaloids are prevalent microbe-based drug classes. • Microbe-derived anticancer agents target various sarcomas, carcinomas, and lymphomas.

Treatment of Sinusoidal Obstruction Syndrome With Defibrotide in Pediatric Cancer Patients Following Nontransplant-associated Chemotherapy: A Case Report and Review of the Literature

Sinusoidal obstruction syndrome (SOS), formerly veno-occlusive disease (VOD), in pediatric cancer patients often presents as a complication of hematopoietic stem cell transplantation, and less commonly secondary to nontransplant-associated chemotherapy. Therapy with defibrotide is well-described as standard care for transplant-associated SOS/VOD, but the treatment of nontransplant-associated SOS/VOD is less clear. We report a 3-year-old with relapsed Wilms tumor and recurrent SOS/VOD, with successful use of defibrotide during chemotherapy. A review of pediatric cancer patients with nontransplant-associated SOS/VOD treated with defibrotide revealed 83 patients, and 66 were in remission. This review supports early treatment with defibrotide in patients with nontransplant-associated SOS/VOD.

Caspase inhibitor z-VAD-FMK increases the survival of hair cells after Actinomycin-D-induced damage in vitro

Actinomycin-D (Act-D) is a highly effective chemotherapeutic agent that induces apoptosis in systemic tissues. Act-D combined with other chemotherapeutic agents exhibits ototoxic effects and causes hearing impairment. To investigate the potential toxic effects of Act-D in the inner ear, we treated cochlear organotypic cultures with varying concentrations of Act-D for different durations. For the first time, we found that Act-D specifically induced HC loss and apoptosis in a dose- and time-dependent manner but not neuronal degeneration. Co-treatment with benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone (z-VAD-FMK), a pan cysteine protease inhibitor, significantly reduced HC loss and apoptosis induced by Act-D, indicating increased cell survival. Taken together, Act-D exposure has ototoxic effects on the auditory system, while z-VAD-FMK prevents Act-D-induced hair cell damage.

"Pre-emptive strike"-the case for early treatment of hepatic sinusoidal obstruction syndrome with defibrotide

The initial signs of hepatic sinusoidal obstruction syndrome (HSOS) can be challenging to recognize in children, especially outside the hematopoietic stem cell transplantation setting. To assist clinicians to promptly identify HSOS, the European Society for Blood and Marrow Transplantation has proposed pediatric HSOS diagnostic criteria which emphasize unexplained consumptive and transfusion-refractory thrombocytopenia. To highlight the importance of these "bellwether" early signs of HSOS and the efficacy of pre-emptive treatment with defibrotide, we describe the case of a child with a right 11th rib primitive neuroectodermal tumor who developed HSOS following focal radiotherapy and actinomycin-D treatment.

Sinusoidal Obstruction Syndrome during Treatment for Wilms' Tumor: A Life-threatening Complication

Context:

Survival rates exceed 90% in Wilms' tumor (WT). Actinomycin-D (ACT-D) which is indispensable in the management of WT is associated with the development of sinusoidal obstruction syndrome (SOS), a potentially fatal complication.

Aims:

The aim is to study the presentation, management, and outcome of SOS complicating ACT-D administration in WT.

Settings and Design:

Retrospective file review conducted in a Pediatric Hematology-Oncology unit.

Materials and Methods:

Patients diagnosed and treated for WT from January 2012 to December 2015 were analyzed. SOS was diagnosed clinically, based on McDonalds criteria, requiring two of the following: jaundice, hepatomegaly and/or right upper quadrant pain, weight gain with or without ascites.

Results:

Of 104 patients treated, SOS occurred in 5 (4.8%). Age: 6 months to 5 years, 3 were girls. Tumor involved left kidney in 3, right in 1 and a horseshoe kidney in 1. Histopathology was consistent with WT in 4 and clear cell sarcoma kidney in 1. One had pulmonary metastases. Three developed SOS preoperatively and two during adjuvant chemotherapy. None received radiotherapy. Clinical manifestations comprised of jaundice, hepatomegaly, ascites/weight gain, respiratory distress, hypotension, and encephalopathy. Laboratory findings included thrombocytopenia, elevated serum transaminases, and coagulopathy. Treatment included fluid restriction, broad spectrum antibiotics, and transfusional support. Two children received N-acetyl cysteine infusion. Defibrotide was administered to two patients. Four recovered and one succumbed to multi-organ failure. Two patients were safely re-challenged with 50% doses of ACT-D.

Conclusions:

SOS is a clinical diagnosis. Systematic supportive care can enable complete recovery. Under close monitoring, re-challenge of ACT-D can be performed in gradually escalating doses.

Defibrotide in the treatment of hepatic veno-occlusive disease

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), represents the most frequent complication in patients in early phase following hematopoietic stem-cell transplantation (HSCT). In its severe form, VOD/SOS can be associated with multiorgan failure and with a mortality rate >80% by day +100. Defibrotide (DF) (a mixture of 90% single-stranded phosphodiester oligonucleotides and 10% double-stranded phosphodiester oligonucleotides derived from controlled depolarization of porcine intestinal mucosal DNA) has been proposed for the treatment of SOS due to its ability to restore thrombo-fibrinolytic balance and protect endothelial cells. The present review highlights why the mechanisms of action of DF allow its successful use in the prevention and treatment of SOS following HSCT.