Matched related donor hematopoietic stem cell transplantation results in a long‐term follow‐up of a pediatric acquired severe aplastic anemia subset: A stem cell source perspective

HSCT has substantially improved pediatric acquired SAA patients' outcomes. Retrospectively, we attempted to assess the outcome of MRD HSCT in 65 pediatric patients referred to a single center from 1992 to 2012. We were particularly interested to find out whether source of SC (PB, n = 40 and BM, n = 25) significantly impacts EFS and GVHD incidence. With a median follow‐up of 45 months, total EFS was 87.7%; EFS for PB and BM groups was 87.5% and 88%, respectively. Acute GVHD (grades 3–4) occurred in 13 patients (PB, n = 10 [25%] and BM, n = 3 [12%]), acute GVHD (grades 2–4) occurred in 24 (PB, n = 16 [40%] and BM, n = 8 [32%]). Extensive chronic GVHD occurred in five patients (PB, n = 3 [7.5%] and BM, n = 2 [8%]). Cox regression revealed that elapsed time of <10 months between diagnosis and HSCT is associated with improved survival (hazard ratio, 95% CI = 1.204, 1.010–1.434, p = 0.038). SC source did not significantly affect EFS, incidence of acute GVHD (grades 3–4), or extensive chronic GVHD (p = 0.938, 0.121, and 0.487, respectively). Based on our findings, pediatric acquired SAA patients are benefitted most if MRD‐HSCT is carried out early in disease process and SC source does not affect outcome of MRD‐HSCT in these patients.     

Successful hematopoietic cell transplantation following cardiac transplantation in two pediatric patients

We report two patients who underwent cardiac transplantation at a young age and subsequently required a HCT for varied indications. Despite the challenges associated with HCT following cardiac transplant, including need for altered immunosuppression, toxicities related to chemotherapy exposure, and infection risks, both patients are currently alive and well. There is a paucity of such successful cases documented in the literature, and these cases highlight the critical importance of an experienced, multidisciplinary team when caring for this patient population.     

Outcomes of pediatric identical living‐donor liver and hematopoietic stem cell transplantation

Chronic IS is associated with significant morbidity in transplant recipients. Moreover, IS does not prevent chronic graft failure frequently. Allograft immune tolerance in LT can be induced by complete donor chimerism through allogenic HSCT combined with identical LDLT. This approach may exempt patients from chronic lifelong IS. However, it is unclear whether its benefits justify its risks. Here, we present three cases from our institution and analyze seven additional reports of children treated with HSCT/LDLT, all receiving HSCT due to hemato‐oncological indications. In eight of 10 cases, donor macrochimerism resulted in allograft tolerance. Nine patients survived. One patient died due to fulminant ADV infection. Further complications were GvHD (n = 3) and bone marrow failure (n = 2). In conclusion, donor‐specific allograft tolerance can be achieved by identical‐donor HSCT/LDLT. However, at present, this approach should generally be limited to selected indications due to a potentially unfavorable risk–benefit ratio. Novel toxicity‐reduced conditioning protocols for HSCT/LDLT in the absence of malignant or non‐hepatic disease may prove to be a sufficiently safe approach for inducing graft tolerance in children receiving a LDLT in the future. This concept may reduce the burden of lifelong IS.     

Surveillance cultures in pediatric allogeneic hematopoietic stem cell transplantation

The value of surveillance cultures in predicting systemic infections and in guiding antimicrobial treatment is controversial. We investigated 57 pediatric allo‐SCTs between 2007 and 2009. ALL (34), AML (5), and severe aplastic anemia (4) were the largest patient groups. Conditioning was TBI‐based in 87% and 54% developed GVHD (21% grade III‐IV). Of the 2594 weekly colonization samples, 24% were positive (fecal bacteria 86%, fecal fungi 16%, Clostridium difficile 16%; throat bacteria 17% and throat fungi 4%). Enterobacteria and enterococci were the most common fecal findings, staphylococci and streptococci in the throat. Of the bacterial stool samples pretransplant, 74% (mostly enterococci) were resistant to our first‐line antibiotics (ceftazidime and cloxacillin). Candida species accounted for the majority of the fungal findings: 62% of the fecal and 78% in the throat. A total of 170 clinical infection episodes were recorded, and in 12 of these, the bacterial blood culture was positive. In 4/12 cases, the pathogen was detected in surveillance culture previously, leading to sensitivity and specificity of 33.3 and 47.4%, respectively. Positive predictive value of bacterial surveillance cultures was 0.9%. The antimicrobial treatment was changed in only five cases based on the surveillance culture results. Weekly surveillance cultures seldom provided clinical benefit and were not cost‐effective.     

Decision making in pediatric hematopoietic cell transplantation: Influential factors vary among diseases

Hematopoietic cell transplantation (HCT) is not a trivial treatment decision in pediatrics. We sought to understand what influences this decision‐making process from the perspectives of the pediatric patients, their family, and physicians. Using integrative review methods, we identified 19 relevant studies: six qualitative, ten quantitative, and three mixed methods. Synthesis of the results revealed six themes describing patient, family, and provider decision‐making processes with distinct subthemes contrasting influential factors among malignant and nonmalignant diseases. Identification of what influences HCT decision making will aid in development of decision support, education, and communication strategies. The child/adolescent voice and provider perspective warrant more attention.     

The challenge of long‐term follow‐up of survivors of childhood acute leukemia after hematopoietic stem cell transplantation in resource‐limited countries: A single‐center report from Brazil

With the number of long‐term HSCT survivors steadily increasing, attention needs to be focused on the late complications and quality of life. We therefore analyzed the outcome of 101 pediatric patients (<18 years old at the time of HSCT) transplanted for acute leukemia between 1981 and 2015 at Complexo Hospital de Clínicas, Federal University of Paraná, Brazil, and who survived at least two years after HSCT. The median follow‐up was 5.9 years (2.0‐29.0); median age at follow‐up was 17.5 years (2.98‐39.0). The 5‐year cumulative incidence of relapse was 27.5% (95% CI 18.6%‐36.4%). Two‐year cumulative incidence of chronic GVHD was 21.8% (95% CI 13.7%‐29.8%). Of the 101 patients, 72 patients (71.3%) presented with late effects. Those surviving longer after HSCT experienced more complications. Patients who received TBI‐based regimen developed more late effects (P = .013) and more endocrinological complications (P = .024). Endocrinological complications were the most common late sequelae found in this study. For childhood survivors, quality of life was not influenced by age (at HSCT or at last visit), time from HSCT, gender, donor, or GVHD. For survivors that no longer were children, only age at last visit impacted financial domain measures, irrespective of gender, donor, or GVHD. The current study confirms the high burden late complications after pediatric HSCT have on the survivors and underlines the importance of extended follow‐up.     

Nutritional status and weakness following pediatric hematopoietic cell transplantation

Survivorship after pediatric HCT has increased over the past decade. Focus on long‐term care and well‐being remains critical due to risk of poor dietary habits and exaggerated sedentary behavior, which can lead to muscle weakness, increased risk for obesity, and cardiometabolic disorders. Nutrition and physical activity are key factors in survivorship; however, data are limited. Comprehensive nutritional assessments, including nutrition‐focused physical examination, grip strength, and food/activity surveys, were completed in 36 pediatric HCT survivors (aged 2‐25 years). Patients were divided into undernutrition, normal‐nutrition, and overnutrition categories. Fifty percent of participants were classified as normal nutrition, 22% undernutrition, and 28% overnutrition. Few patients met the U.S. Dietary Guidelines recommended intake for vegetables, fiber, saturated fat, and So FAS. Patients in the undernutrition group demonstrated significantly lower grip strength than those in the normal‐ and overnutrition groups. When grip strength was normalized to body mass, patients in the overnutrition group had the highest prevalence of weakness. Using NHANES reference data, maximum grip strength and NGS cutoffs were identified that could significantly distinguish the nutrition groups. Comprehensive nutritional assessments and grip strength measurements are feasible, non‐invasive, easy to perform, and inform both under‐ and overnutrition in pediatric HCT survivors.     

Successful fludarabine‐based hematopoietic stem cell transplantation in a pediatric patient with idiopathic CD4+ lymphocytopenia

Idiopathic CD4+ lymphocytopenia (ICL) is a rare immunodeficiency disease with severe CD4 T‐cell depletion, leading to serious opportunistic infections. The optimal treatment of ICL has not been determined, especially in severe form of the disease. Here, we report an eight‐yr‐old girl with ICL who was successfully treated with fludarabine‐based conditioning HSCT. To the best of our knowledge, this is the first pediatric ICL case that was treated by HSCT. Allogeneic HSCT with a reduced intensity condition (RIC) regimen may be a feasible and curative treatment option in ICL patients with recurrent life‐threatening complications.     

Mycophenolate mofetil for treatment of steroid‐refractory acute graft‐versus‐host disease after pediatric hematopoietic stem cell transplantation

A standard treatment is yet to be established for steroid‐refractory acute aGVHD following HSCT. The effects of MMF have not been well studied in children with aGVHD. We evaluated the effectiveness of oral MMF in 14 children with steroid‐refractory aGVHD (grade II in one patient, grade III to IV in 13 patients). The median initial dose of MMF was 40 mg/kg/day (range, 30–74) and was increased by 1.5–2 times if manifestations of GVHD did not improve. Within four wk of treatment, seven patients (50%) achieved CR, and four (29%) had a PR. Within eight wk, 11 patients (79%) achieved CR without using additional agents. Overall, 12 patients are alive and in remission with a median follow‐up of 35 months (range, 14–86). The median maximum dose of MMF was 60 mg/kg/day (range, 34–107). No fatal toxicity was observed, including MMF‐related infections. MMF appears to be highly effective for steroid‐refractory aGVHD when used at a higher dose than has been described previously. Larger studies and pharmacokinetic analysis are required to evaluate its efficacy and toxicity and find the optimal dose of MMF in children.     

Pharmacokinetic analysis for model‐supported therapeutic drug monitoring of busulfan in Japanese pediatric hematopoietic stem cell transplantation recipients

This prospective observational study analyzed the pharmacokinetics of busulfan in Japanese children and evaluated the predicting accuracy of previous pediatric PPK models of busulfan. This study enrolled five patients (aged 2‐12 years, BW 14‐48 kg) receiving a busulfan‐based conditioning regimen for hematopoietic stem cell transplantation at our hospital between January 2017 and December 2018. All patients received a 2‐hour intravenous busulfan infusion four times daily for a total of 16 doses. After the infusions, 51 plasma samples were collected with the plasma busulfan concentration measured by liquid chromatography‐tandem mass spectrometry. PPK model fitting was analyzed using the (%MPE) and the (%MAPE). Limited sampling strategies for estimating busulfan AUC were also evaluated. High interpatient variability was observed in the PK parameters. The most suitable PPK model that reflected our data was McCune's two‐compartment model (%MPE ?8.7, %MAPE 19.3). A combination sampling method using the busulfan concentration at 2 and 6 hours after the start of the first busulfan dose was found to be able to estimate AUC_4 day. These results provide useful information on busulfan therapeutic drug monitoring in the Japanese pediatric population.     

The incidence of autoimmune hemolytic anemia in pediatric hematopoietic stem cell recipients post‐first and post‐second hematopoietic stem cell transplant

The reported incidence of post‐allogeneic HSCT AIHA was between 4.4% and 6% following a single transplant. Cord blood transplantation, T‐cell depletion, and chronic GvHD are significantly associated with post‐transplant AIHA. During an 11‐yr period, data for 500 pediatric HSCT recipients were eligible for evaluation of the incidence of AIHA post‐first and post‐second transplants. Demographic, transplant, and post‐transplant‐related variables were analyzed. Twelve of 500 (2.4%) recipients at a median of 273 days and seven of 72 (9.7%) recipients at a median of 157 days developed AIHA post‐first and post‐second HSCT, respectively. Post‐first HSCT, none of the MRD recipients developed AIHA (0/175 MRD vs. 12/325 other donors, p = 0.04). Four of 12 required a second HSCT to control the AIHA. After the second HSCT, MUD was significantly associated with the development of AIHA. No other variables were associated with the post‐second transplant AIHA. The incidence of AIHA post‐first and post‐second HSCT was less than the reported. The increased incidence of AIHA among recipients of second HSCT is most likely due to the profound immune dysregulation. A much larger, prospective study would be needed to evaluate the incidence, complications, and management of post‐transplant AIHA.