Reduced toxicity matched sibling bone marrow transplant results in excellent outcomes for severe congenital neutropenia.

Severe congenital neutropenia (SCN) is caused by germline mutations, most commonly in ELANE, impacting neutrophil maturation and leading to high risk of life-threatening infections. Most patients with ELANE-mutant SCN can achieve safe neutrophil counts with chronic Granulocyte-Colony Stimulating Factor (G-CSF). However, up to 10% of patients have neutropenia refractory to G-CSF and require allogeneic stem cell transplant. Traditional conditioning for these patients includes busulfan and cyclophosphamide which is associated with significant toxicities. We present five patients with SCN without myeloid malignancy transplanted using a reduced toxicity regimen of busulfan, fludarabine and thymoglobulin. 5 pediatric patients with SCN underwent matched sibling donor bone marrow transplant (MSD-BMT) between 2014-2022 on or per CHP14BT057 (NCT02928991), a prospective, single center trial testing elimination of cyclophosphamide from conditioning in pediatric patients with single lineage inherited BMF syndromes. All patients had MSDs and no evidence of MDS. Conditioning consisted of PK-adjusted busulfan, fludarabine, and thymoglobulin, with calcineurin inhibitor and mycophenolate mofetil GVHD prophylaxis. With median follow-up of 48.4 months, overall and event-free survival were 100%. There was no acute GVHD and one instance of chronic limited GVHD. Patients exhibited >95% donor myeloid chimerism at 5 years post-BMT. Two patients experienced CMV reactivation without end-organ disease, and no other viral reactivation or significant infections occurred. MSD-BMT with reduced toxicity myeloablation for SCN provides excellent outcomes while minimizing toxicity. These data suggest that busulfan, fludarabine, and ATG can be considered an efficacious, low-toxicity standard of care regimen for patients with SCN undergoing MSD-BMT.

Can extending time between vital sign checks improve sleep in hematopoietic stem cell transplant patients? Testing feasibility, acceptability, and preliminary efficacy.

BACKGROUND: Patients undergoing hematopoietic stem cell transplant (HSCT) experience barriers to quality sleep. Frequent vital sign checks are necessary early posttransplant given risk of complications but can disrupt sleep. This study tested feasibility and acceptability of extending time between checking vitals (EVs) from every 4 to every 6 h to improve sleep. PROCEDURE: HSCT patients ages 8-21 years (N = 50, mean age = 14.06, SD = 3.58) and their caregivers were enrolled 1-2 days prior to transplant, and 40 patients completed the 15-day study (NCT04106089). Patients wore an actigraph to estimate sleep and provided self- and caregiver-report of sleep. Sleep was observed for nights 0 to +4 posttransplant, and patients were then randomized to EVs either Days +5 to +9 or +10 to +14. Patients were assessed daily for medical eligibility to receive EVs; on days patients were eligible, nightshift nurses (N = 79) reported EV acceptability. RESULTS: Of 200 potential nights for EVs (5 nights x 40 patients), patients were eligible for EVs on 126 nights (63% of eligible nights), and patients received EVs on 116 (92%) of eligible nights. Most patients received EVs ≥3 nights (n = 26, 65%, median = 3 nights). Most patients (85%), caregivers (80%), and nurses (84%) reported that patients used the additional 2 h during EVs for sleep, with reporters indicating moderate to high acceptability. There was preliminary evidence of efficacy indicated by caregiver-reported sleep disturbance and actigraphy-estimated improvements in sleep efficiency during EVs. CONCLUSION: Extending time between vitals checks is highly acceptable to patients, caregivers, and nurses, and may offer a feasible approach to improve sleep in pediatric HSCT.

Non-myeloablative conditioning is sufficient to achieve complete donor myeloid chimerism following matched sibling donor bone marrow transplant for myeloproliferative leukemia virus oncogene (MPL) mutation-driven congenital amegakaryocytic thrombocytopenia: Case report.

Background: Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare platelet production disorder caused mainly by loss of function biallelic mutations in myeloproliferative leukemia virus oncogene (MPL), the gene encoding the thrombopoietin receptor (TPOR). Patients with MPL-mutant CAMT are not only at risk for life-threatening bleeding events, but many affected individuals will also ultimately develop bone marrow aplasia owing to the absence of thrombopoietin/TPOR signaling required for maintenance of hematopoietic stem cells. Curative allogeneic stem cell transplant for patients with CAMT has historically used myeloablative conditioning; however, given the inherent stem cell defect in MPL-mutant CAMT, a less intensive regimen may prove equally effective with reduced morbidity, particularly in patients with evolving aplasia. Methods: We report the case of a 2-year-old boy with MPL-mutant CAMT and bone marrow hypocellularity who underwent matched sibling donor bone marrow transplant (MSD-BMT) using a non-myeloablative regimen consisting of fludarabine, cyclophosphamide, and antithymocyte globulin (ATG). Results: The patient achieved rapid trilinear engraftment and resolution of thrombocytopenia. While initial myeloid donor chimerism was mixed (88% donor), due to the competitive advantage of donor hematopoietic cells, myeloid chimerism increased to 100% by 4 months post-transplant. Donor chimerism and blood counts remained stable through 1-year post-transplant. Conclusion: This experience suggests that non-myeloablative conditioning is a suitable approach for patients with MPL-mutant CAMT undergoing MSD-BMT and is associated with reduced risks of conditioning-related toxicity compared to traditional myeloablative regimens.

Cytokine Release Syndrome: Inpatient Care for Side Effects of CAR T-Cell Therapy
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BACKGROUND: Pediatric patients with relapsed and refractory acute lymphoblastic leukemia are more often being treated with chimeric antigen receptor (CAR) T-cell therapy. As with any new therapy, the management of this patient population has a unique set of challenges. The side effects of this therapy can range from mild to severe, with cytokine release syndrome being the most common reason for hospitalization.
. OBJECTIVES: This article presents common side effects, treatments, and challenges of caring for hospitalized patients who have received CAR T-cell therapy.
. METHODS: A case study is used to illustrate a patient's inpatient hospitalization course after receiving CAR T-cell therapy, including the management of treatment-related toxicities.
. FINDINGS: As treatments emerge, nurses will be challenged with learning the associated side effects and toxicities. CAR T-cell therapy can result in a unique trajectory of potential symptoms and the potential for complete resolution of disease.