Low-dose liposomal amphotericin B for antifungal prophylaxis in paediatric allogeneic haematopoietic stem cell transplantation

BACKGROUND

Primary antifungal prophylaxis in paediatric allogeneic HSCT recipients is mainly based on azoles, which can have related toxicity and drug interactions. Low-dose liposomal amphotericin B (L-AmB) is an attractive intravenous alternative because of its low toxicity and lower risk of interactions.

OBJECTIVES

To evaluate the effectiveness and safety of L-AmB (1 mg/kg/day) for primary antifungal prophylaxis in pre-engraftment paediatric HSCT patients.

PATIENTS AND METHODS

Retrospective, observational study including all consecutive patients aged ≤18 years who underwent HSCT and received antifungal prophylaxis with intravenous L-AmB (1 mg/kg/day, from day -1 to 48 h before discharge) between January 2012 and December 2016.

RESULTS

In total, 125 HSCT procedures in 118 patients were included, median age 7.2 years (IQR 4.2-11.5). Haematological malignancies were the main underlying condition (63.6%), and 109 (87.2%) were considered at high risk for invasive fungal infection (IFI). Ten patients (7.7%), all high risk, developed breakthrough IFI (three Candida spp., seven invasive mould infections) and tended to have higher overall mortality. The only statistically significant risk factor for IFI was cytomegalovirus co-infection. Adverse events, all grade I, occurred in 25 (20%), requiring L-AmB withdrawal in one case. Overall survival at 30 days was 99.2%. At study completion, one patient had died of IFI.

CONCLUSIONS

The incidence of breakthrough IFI was comparable to that of previous reports, with a very low rate of significant toxicity. Thus, prophylactic L-AmB may be a safe, effective option for antifungal prophylaxis in the pre-engraftment phase for children undergoing HSCT, even those at high risk.

Use of Eculizumab in Pediatric Patients With Transplant Associated Thrombotic Microangiopathy

Background: Transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication of hematopoietic stem cell transplantation (HSCT) associated with high morbidity and mortality. High-risk TA-TMA (hrTA-TMA) is characterized by multifactorial endothelial damage caused by environmental stressors, dysregulation of the complement system, and genetic predisposition. Complement inhibitors have significantly decreased mortality and are the current treatment of choice. In this article, we describe our experience with the use of eculizumab in pediatric patients diagnosed with hrT-TMA after HSCT. Method: Retrospective study of pediatric patients with hrTA-TMA treated with eculizumab between January 2016 and December 2020. Results: Four pediatric patients aged 1, 12, 14, and 17 years at the time of HSCT were diagnosed with hrTA-TMA and treated with eculizumab during the study. At diagnosis, they all had renal impairment with proteinuria, and hypertension under treatment with at least two antihypertensive drugs. The patient who presented multisystemic involvement died instead of treatment. The three patients with exclusive renal involvement achieved TA-TMA resolution after treatment with eculizumab for 65, 52, and 40.6 weeks and were able to stop treatment. The two patients with follow-up data one year after eculizumab withdrawal sustained a favorable response. Eculizumab was well tolerated, and with adequate vaccination and antibiotic prophylaxis, did not increase the risk of infection. Conclusions: Eculizumab appears to be both safe and effective for the treatment of hrTA-TMA in patients with renal impairment. Early diagnosis and initiation of treatment may improve response. Eculizumab withdrawal can be contemplated in patients who achieve laboratory and clinical resolution of TA-TMA.