The impact of alternative donor types on viral infections in pediatric hematopoietic stem cell transplantation

Viral infections remain one of the most important complications following allogeneic HSCT. Few reports compare virus infection between different donor types in pediatric patients. We retrospectively analyzed viral infections and the outcome of one hundred and seventy‐one pediatric patients (median 7.38 years) who underwent allogeneic HSCT from matched related donor (MRD, n = 71), 10 of 10 HLA allele‐matched unrelated donors (MUD1; n = 29), 9 of 10 HLA allele‐matched unrelated donors (MUD2; n = 40), and haploidentical donors (n = 31). PCR screening for BK virus, adenovirus, Epstein‐Barr virus, parvovirus B19, human herpesvirus 6, and CMV were performed routinely weekly. Infections between 0‐30, 31‐100, and 101 days‐2 years were identified separately. BK virus and CMV reactivations were significantly low in MRD transplant patients (P = .046 and P < .0001, respectively), but incidences of all virus infections between MUD1, MUD2, and haplo‐HSCT were found statistically not different. The OS was found to be affected by having one or multiple virus infection (P = .04 and P = .0008). Despite antiviral prophylaxis and treatments, post‐transplant viral infections are associated with reduced overall survival. Haplo‐HSCT is comparable with MUD transplantation in the setting of viral infections. A larger study group and prospective studies are needed to confirm this observation.     

Incidence,risk factors,and outcome of blood stream infections during the first 100 days post‐pediatric allogeneic and autologous hematopoietic stem cell transplantations

Bloodstream infections (BSI) are a frequently observed complication after hematopoietic stem cell transplant (HSCT). Retrospective analysis of clinical and microbiological data during the first 100 days from 302 consecutive pediatric patients who underwent HSCT for a malignant disease at our institute between January 2013 and June 2017. A total of 164 patients underwent autologous and 138 allogeneic HSCT. The overall incidence of BSI was 37% with 92% of infectious episodes occurring during the pre‐engraftment phase. Gram‐positive bacteria (GPB) accounted for 54.6% of the isolated pathogens, gram‐negative bacteria (GNB) for 43.9%, and fungi for 1.4%. Coagulase‐negative staphylococci and Escherichia coli were the most commonly isolated GPB and GNB, respectively. Forty‐five percent of GNB were extended‐spectrum beta‐lactamase producers and 21% were multidrug‐resistant organisms. Fluoroquinolone resistance was 92% and 68%, among GPB and GNB, respectively. Risk factors for BSI in univariate analysis were allogeneic HSCT, delayed time to engraftment more than 12 days, previous BSI before HSCT, and alternative donor. In multivariate analysis, only HSCT type (allogeneic vs autologous P = .03) and previous BSI within 6 months before HSCT (P = .016) were significant. Overall survival at day 100 was 98% and did not differ significantly between patients with and without BSI (P = .76). BSI is common in children undergoing HSCT for malignant diseases. Allogeneic HSCT recipients and previous BSI within 6 months before HSCT are associated with increased risk of post‐transplant BSI. With current supportive measures, BSI does not seem to confer an increased risk for 100‐day mortality.     

Control of graft‐versus‐host disease with rabbit anti‐thymocyte globulin,rituximab, and bortezomib in TCRαβ/CD19‐depleted graft transplantation for leukemia in children: a single‐center retrospective analysis of two GVHD‐prophylaxis regimens

Both acute GVHD and chronic GVHD remain the leading cause of morbidity and death after allogeneic HSCT. We conducted a retrospective analysis comparing two GVHD‐prophylaxis regimens: 35 patients received “Regimen 1” (horse ATG, tacrolimus, and methotrexate) and 46 “Regimen 2” (rabbit ATG, rituximab, and peritransplant bortezomib). All 81 patients with a median age of 9 (0.6‐23) years with ALL (n = 31) or AML (n = 50) in complete remission received TCRαβ/CD19‐depleted transplants between May 2012 and October 2016, from 40 HLA‐matched unrelated and 41 haploidentical donors. After a median follow‐up of 3.9 years, the CI of acute GVHD II‐IV was 15% (95% CI: 7‐30) in the “Regimen 2” group and 34% (95% CI: ?54) in the “Regimen 1” group, P = .05. “Regimen 2” was also more effective in the prevention of chronic GVHD; the CI at 1 year after HSCT was 7% (95% CI: 2‐19) vs 31% (95% CI: 19‐51), P = .005. The CI of relapse at 3 years adjusted for the GVHD‐prophylaxis regimen groups 31% (95% CI: 19‐51) for the “Regimen 1” vs 21% (95% CI: 11‐37) for the “Regimen 2”, P = .3. The retrospective observation suggests that the use of the rATG, rituximab, and bortezomib was associated with significantly lower rate of GVHD without the loss of anti‐leukemic activity.     

Safety of hematopoietic cell infusion in children with malignant and non‐malignant diseases

HPC infusions have been associated with a variety of adverse events related to either patient or HPC product‐related factors. Studies documenting infusion‐related AEs in children are limited. We reviewed HPC infusion records in 354 children. Infusion‐related adverse events were classified as follows: grade 0—absent, grade I—mild, grade II—moderate, grade III—severe, grade IV—life‐threatening, and grade V—death. The percentage of patients with grade 0, I, and II‐IV AEs was as follows: 0 = 67%, I = 23.4%, and II‐V = 9.6% (one patient had fatal anaphylactic reaction to dimethyl sulfoxide). The incidence of grade II‐IV hypertension was 7.1%. There was a higher incidence of AEs with infusion of allogeneic bone marrow versus allogeneic PBSCs (47.4% vs 25.3%, P = .001). Cryopreserved products had a lower incidence of infusion‐associated AEs compared with fresh HPC products (24% vs 39.4%, P = .003). Allogeneic HPC infusion volume (>100 mL) was a significant risk factor for infusion‐associated AEs (P < .001). Patients >10 years who received autologous HPC infusions had higher risk of AEs when compared to patients <10 years (P = .01). Our study demonstrated that despite a high incidence of infusion‐associated hypertension, HPC infusion is relatively safe in children. Investigating strategies to optimize management of hypertension in the setting of HPC infusion is warranted.     

Quantiferon‐Cytomegalovirus assay: A potentially useful tool in the evaluation of CMV‐specific CD8+ T‐cell reconstitution in pediatric hematopoietic stem cell transplant patients

Pediatric HSCT recipients are at high risk for CMV reactivation due to their immature immune system and therapy following transplantation. Reconstitution of CMV‐specific T‐cell immunity is associated with control and protection against CMV. The clinical utility of monitoring CMV‐specific CMI to predict CMV viremia in pediatric HSCT patients using the Quantiferon‐CMV (QIAGEN^®) test was investigated prospectively. Thirty‐seven pediatric allogeneic HSCT recipients were enrolled from 3/2010‐6/2012. CMV viremia was detected via weekly real‐time PCR. The Quantiferon‐CMV test was conducted pretransplant, early after transplantation, 30, 90 , 180 , 270, and 360 days post‐transplantation. The incidence of CMV viremia was 51% (19/37) with half of the episodes within ≤30 days post‐transplant. Fifteen patients showed CMV‐specific immunity (average of 82 days). The cumulative incidence of CMV reactivation in patients who developed CMV‐specific immunity was lower than those who did not (15% vs 53%; P = .023). The ROC statistical analysis showed that the AUC was 0.725 in predicting viremia, for Quantiferon‐CMV test. In this cohort, the Quantiferon‐CMV assay was a valuable method for identifying pediatric HSCT patients at high risk for CMV viremia, suggesting potential clinical utility to individualize patient's management post‐transplant.     

Hemophagocytic lymphohistiocytosis is a sign of poor outcome in pediatric Epstein‐Barr virus‐associated post‐transplant lymphoproliferative disease after allogeneic hematopoietic stem cell transplantation

EBV‐related PTLD developing after HSCT is a potentially life‐threatening disease. HLH is uncommon after allogeneic HSCT. Data on outcome of patients with PTLD and concomitant HLH after allogeneic HSCT are limited. In this retrospective study, we collected demographic, clinical, laboratory, and outcome data for 408 patients who underwent allogeneic HSCT from 2006 to 2015. Graft source included CB (n = 135; 33.1%), PBSCs (n = 34; 8.3%), and BM (n = 239; 58.6%). Eight out of 408 patients (2%) developed EBV‐PTLD with a median age at HSCT of 5.9 years (range: 2.3‐17.3). All eight patients received ATG as part of the conditioning regimen. Graft source was PBSC in three patients (37.5%), BM in four patients (50%), and CB in one patient (12.5%). Donors were matched unrelated in five patients (62.5%) and matched sibling in three patients (37.5%). Seven out of eight patients developed EBV‐PTLD within the first 100‐day post‐HSCT. Lymph node biopsy revealed early lesions in three patients, polymorphic in three patients, and monomorphic PTLD in two patients. Three patients (37.5%) died within 1 month of EBV‐PTLD diagnosis. All deceased patients developed HLH manifestations with two of them meeting HLH diagnostic criteria and one having an incomplete workup. PTLD after allogeneic HSCT with manifestations of HLH is associated with high mortality. Early identification and treatment of EBV‐PTLD seems imperative to control the disease, especially if signs of HLH are evolving.     

Autoimmune hemolytic anemia and immune thrombocytopenia following hematopoietic stem cell transplant: A critical review of the literature

Autoimmune cytopenias (AIC) post‐hematopoietic stem cell transplant (HSCT) are rare but exceptionally challenging complication. We conducted a comprehensive literature review and identified a pooled incidence of post‐HSCT autoimmune hemolytic anemia and/or immune thrombocytopenia of 2.66% (SE = 0.27) in pediatric patients. Nonmalignant disease, unrelated donor transplant, peripheral or cord blood stem cell source, conditioning regimen without total body irradiation, and presence of chronic graft‐versus‐host disease were prominent risk factors. Treatment was highly variable, and cytopenias were commonly refractory. AIC represent a significant post‐HSCT complication. We report here the incidence, risk factors, and possible biology behind the development of AIC in pediatric post‐HSCT patients.     

Is there an optimal organ acceptance rate for pediatric heart transplantation: “A sweet spot”?

Despite a limited supply of donors, potential donor hearts are often declined for subjective concerns regarding organ quality. This analysis will investigate the relationship between donor heart AR and patient outcome at pediatric transplant centers. The UNOS database was used to identify all match runs for pediatric candidates (age < 18 years) from 2008 through March 2015 in which a heart offer was ultimately placed. Centers which received ≥10 offers/y were included (10 634 offers, 38 centers). Transplant centers were stratified based on their AR: low (<20%, n = 13), medium (20%‐40%, n = 16), or high (>40%, n = 9). Low AR centers experienced worse negative WL outcome compared with medium (P = .022) and high (P = .004) AR centers. Low AR centers had similar post‐transplant graft survival to medium (P = .311) or high (P = .393) AR centers; however, medium AR centers had better post‐transplant graft survival than high AR centers (P = .037). E‐F survival from listing regardless of transplant was worse for low AR centers compared with medium (P < .001) or high (P = .001) AR centers. Low AR centers experience worse WL outcomes without improvement in post‐transplant outcomes. High AR centers experience higher post‐transplant graft failure than medium AR centers. AR of 20%‐40% appears to have optimal WL and post‐transplant outcomes.     

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.     

Analysis of rabbit anti‐thymocyte globulin vs basiliximab induction in pediatric liver transplant recipients

Literature is limited comparing induction immunosuppression in pediatric liver transplant (LTx) recipients. This is a single‐center, retrospective cohort study of primary pediatric liver transplants at our center between 2005 and 2016 who received either basiliximab (BSX) or rabbit anti‐thymocyte globulin (rATG) induction. Maintenance immunosuppression consisted of tacrolimus ± a corticosteroid taper. Exclusions included receipt of an ABO‐incompatible graft, retransplantation, and multi‐organ transplantation. Primary outcomes were incidence of treated biopsy‐proven acute rejection (tBPAR) and PTLD within the first year and infections within 90 days of LTx. Secondary outcomes included graft and patient survival, time to first tBPAR, and incidence of steroid‐resistant rejection (SRR) within the first year post‐LTx. A total of 136 patients were included in the final analysis of which 57 patients (42%) received BSX induction. Patients who received rATG induction with or without a 2‐week corticosteroid taper experienced significantly more tBPAR compared to those who received BSX induction with a 6‐month corticosteroid taper (55.7% vs 33.3%, P = .01). There were no differences in the incidence of PTLD, infections, SRR, graft or patient survival, or time to first tBPAR between the two groups . Induction with rATG either with or without a short corticosteroid taper was associated with significantly more tBPAR in primary pediatric LTx recipients when compared to BSX induction with a prolonged corticosteroid taper in the setting of maintenance immunosuppression with tacrolimus.     

Hematopoietic stem cell transplantation for children with primary immunodeficiency diseases: Single center experience in Jordan

HSCT can be curative for many PID. Little is known about the outcome of HSCT for patients with PID in the developing countries. We retrospectively reviewed all children with PID who received HSCT at KHCC in Jordan between August 2003 and October 2011. Twenty‐eight patients were identified. The median age was 16 months (3 months–17 yr). Patients' diagnoses were SCID (n = 16), CHS (n = 3), HLH (n = 3), WAS (n = 2), Griscelli syndrome (n = 1), ALPS (n = 1), Omenn's syndrome (n = 1), and DiGeorge syndrome (n = 1). Seventeen patients received HLA‐matched related HSCT, eight received maternal un‐manipulated haploidentical HSCT, and three received unrelated cord blood transplantation. Nine patients (32%) developed BCGosis secondary to reactivation of pretransplant vaccination. Three died while still receiving anti‐tuberculosis drugs, one still on treatment, and all others have recovered. Six patients had graft failure; four of them received no conditioning regimens. At a median follow up of 32 months (range 1‐67), 21 patients are alive, with overall survival of 72%. We conclude that HSCT for PID patients can be performed with a good outcome in developing countries; however, delayed diagnosis or referral and BCG reactivation are unique challenges.     

Transplant‐related mortality and survival in children with malignancies treated with allogeneic hematopoietic stem cell transplantation. A multicenter analysis

The aim of the study was to assess the risk of TRM in pediatric patients treated for malignant disorders with allogeneic HSCT, according to different risk factors. The treatment outcome was analyzed in 299 pediatric patients treated in pediatric transplant departments from 2006 to 2015. To compare the outcome, patients were analyzed all together and in groups according to the diagnosis, age at transplant, donor type, disease status, stem cell source, and pediatric TRM score. At the end of the observation time, 82 patients were alive, 82 died, of which 40 due to transplant‐related reasons. The most frequently observed causes of TRM were toxic complications effecting with organ failure (38%), followed by infections (26%), PTLD (14.3%), and GvHD (16.7%). There was no statistical difference in the incidence of TRM depending on stem cell source (P = .209) and primary diagnosis (P = .301). According to TRM score, TRM was significantly higher in high‐risk group (P = .006). High‐risk patients had lower survival comparing to low/intermediate group (P = .0001). OS did not differ between ALL, AML, and MDS/JMML groups. The study confirmed the utility of factors included in TRM score stratification in assessing the risk of transplant procedure in pediatric patients transplanted for malignancies.     

Risk factors for oral mucositis in children receiving hematopoietic cell transplantation for primary immunodeficiencies: A retrospective study

OM is a frequent complication for patients undergoing HSCT. The aim of this study was to evaluate the possible risk factors for OM in children undergoing HSCT for PI. A retrospective study was carried out on 55 consecutive medical records of patients with PI (including osteopetrosis) who underwent HSCT. Age at the time of HSCT, gender, diagnosis, type of donor, conditioning regimen, engraftment, graft‐versus‐host disease, and severity and duration of OM were collected at the beginning of the conditioning until day 100 post‐HSCT or death. OM was measured using the WHO scale. Patients' age range at the time of HSCT was quite wide; 59.2% of the patients who were under nine months (n = 13) developed OM vs. 87.8% of the patients older than nine months (n = 29) (p = 0.01). T‐cell positive patients had a statistically significant higher risk of developing OM (p = 0.04), as did those receiving a more intensive conditioning regimen (p < 0.01). PI patients undergoing HSCT are at higher risk of developing OM if the PI is a T‐lymphocyte‐positive disease and/or if the HSCT recipient is over nine months of age.     

Measles,mumps, rubella (vaccine) and varicella vaccines in pediatric liver transplant: An initial analysis of post‐transplant immunity

Varicella and measles infection represents a significant source of morbidity and mortality for pediatric LT recipients. We evaluated the prevalence and correlates of post‐transplant immunity in pediatric LT recipients previously immunized against measles (n = 72) and varicella (n = 67). Sixteen of seventy‐two (22%) patients were measles non‐immune, and 42/67 (63%) were varicella non‐immune after LT. Median time from LT to titers for measles and varicella was 4.0 and 3.3 years, respectively. In the measles cohort, non‐immune patients received fewer pretransplant vaccine doses (P = 0.026) and were younger at both time of vaccination (P = 0.006) and LT (P = 0.004) compared with immune patients. Upon multivariable analysis, weight > 10 kg at LT (OR 5.91, 95% CI 1.27‐27.41) and technical variant graft (OR 0.07, 95% CI 0.01‐0.37) were independently, significantly associated with measles immunity. In the varicella cohort, non‐immune patients received fewer pretransplant vaccine doses (P = 0.028), were younger at transplant (P = 0.022), and had less time lapse between their last vaccine and transplant (P = 0.012) compared with immune patients. Upon multivariate analysis, time > 1 year from last vaccine to LT was independently, significantly associated with varicella immunity (OR 3.78, CI 1.30‐11.01). This study demonstrates that non‐immunity to measles and varicella is a prevalent problem after liver transplantation in children and identifies 3 unique risk factors for non‐immunity in this high‐risk 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.     

Sleep disruption in caregivers of pediatric stem cell recipients

Parents/caregivers of hospitalized patients are at risk of sleep disruption. We performed a cross‐sectional quantitative and qualitative evaluation of sleep in parents/caregivers of children undergoing hematopoietic stem cell transplant (HSCT; n = 17). Additionally, we explored the frequency of room entries for hospitalized patients undergoing HSCT (n = 189 nights). Twelve caregivers (71%) demonstrated significant sleep disturbance, 12 (71%) described sleep quality as poor, 15 (88%) averaged < 6 hours of sleep per night, 14 (82%) awakened at least four times per night. Patient rooms were entered a median of 12 times per night (interquartile range 10–15). Intervention studies to improve caregiver sleep during hospitalization are needed.     

Pericardial effusion following hematopoietic stem cell transplantation in children: Incidence,risk factors,and outcomes

PCE is a complication of HSCT that has previously been described in small single‐center studies. This study aimed to assess the frequency of, risk factors for, and outcomes of children with a PCE following HSCT across a large multi‐center cohort. All patients ≤21 years undergoing first HSCT (1/2005‐9/2015) were identified from the Pediatric Health Information System. ICD‐9 codes were used to identify patients with a PCE during or following the transplant encounter. Multivariable modeling assessed risk factors for developing a PCE and assessed the impact of PCE on patient outcome. Of 10 455 included patients, 739 (7.1%) developed a PCE (median 69 days post‐HSCT, interquartile range 33‐165 days). PCE developed more commonly in allogeneic vs autologous HSCT recipients (9.1% vs 2.9%, P < .001). Among allogeneic HSCT recipients, independent risk factors for PCE included thrombotic microangiopathy (AHR 2.94, 95% CI 2.16‐4.00), heart failure (AHR 2.07, 95% CI 1.61‐2.66), PCE pre‐HSCT (AHR 1.92, 95% CI 1.19‐3.09), arrhythmia (AHR 1.76, 95% CI 1.44‐2.16), graft‐versus‐host disease (AHR 1.31, 95% CI 1.05‐1.62), female sex (AHR 1.28, 95% CI 1.07‐1.52), and malignancy (AHR 1.28, 95% CI 1.02‐1.60). Allogeneic HSCT patients with PCE demonstrated worse survival than those without PCE (5‐year survival 50.8% vs 76.9%, P < .001). PCE was independently associated with mortality (AHR 1.96, 95% CI 1.62‐2.37) following allogeneic HSCT and was not impacted by pericardial intervention. PCE occurs more commonly in patients following allogeneic (vs autologous) HSCT and is associated with inferior outcomes.     

Comparison of survival outcome between donor types or stem cell sources for childhood acute myeloid leukemia after allogenic hematopoietic stem cell transplantation: A multicenter retrospective study of Study Alliance of Yeungnam Pediatric Hematology‐oncology

We compared transplant outcomes between donor types and stem cell sources for childhood acute myeloid leukemia (AML). The medical records of children with AML in the Yeungnam region of Korea from January 2000 to June 2017 were reviewed. In all, 76 children with AML (male‐to‐female ratio = 46:30) received allogenic hematopoietic stem cell transplantation (allo‐HSCT). In total, 29 patients received HSCT from either a matched‐related donor or a mismatched‐related donor, 32 patients received an unrelated donor, and 15 patients received umbilical cord blood. In term of stem cell sources, bone marrow was used in 15 patients and peripheral blood in 46 patients. For all HSCT cases, the 5‐year overall survival (OS) was 73.1% (95% CI: 62.7‐83.5) and the 5‐year event‐free survival (EFS) was 66.1% (95% CI: 54.5‐77.7). There was no statistical difference in 5‐year OS according to the donor types or stem cell sources (P = .869 and P = .911). There was no statistical difference in 5‐year EFS between donor types or stem cell sources (P = .526 and P = .478). For all HSCT cases, the 5‐year relapse rate was 16.1% (95% CI: 7.3‐24.9) and the 5‐year non‐relapse mortality (NRM) was 13.3% (95% CI: 5.1‐21.5). There was no statistical difference in the 5‐year relapse rate according to the donor types or stem cell sources (P = .971 and P = .965). There was no statistical difference in the 5‐year NRM between donor types or stem cell sources (P = .461 and P = .470).     

A systematic review of acute kidney injury in pediatric allogeneic hematopoietic stem cell recipients

The process of allogeneic HSCT in children is associated with frequent AKI and mortality, but the epidemiology is not widely reported. The aim of this review was to summarize the available evidence on incidence, risk factors, timing, and prognosis of AKI in children following HSCT. We systematically reviewed all observational studies reporting incidence and outcomes of AKI in pediatric allogenic HSCT recipients. The minimum criteria for AKI were defined as an increase in sCr  ≥ x1.5 or urine output ≤0.5 mL/kg/min over six h. Medline and Embase were searched until March 2014. From 993 electronic records, five were eligible for inclusion (n = 571 patients). The average incidence of AKI within the first 100 days following HSCT was 21.7% (range 11–42%), and the average time of onset was 4–6 wk post‐transplant. Risk factors for AKI included cyclosporine toxicity, amphotericin B and foscarnet, SOS, and having a mismatched donor. There were conflicting reports on whether AKI was associated with the development of CKD. AKI is a common and potentially life‐threatening complication following HSCT in children. Further quality observational studies are needed to accurately determine the epidemiology and prognosis of AKI in this population.