Pediatric and Young Adult Vulvovaginal Graft-versus-Host Disease.

Vulvovaginal graft-versus-host disease (GVHD) is an underdiagnosed and poorly recognized complication of hematopoietic stem cell transplantation (HSCT). Previous studies have reported findings restricted to predominantly adult populations. We report a case series of pediatric and young adult vulvovaginal GVHD, which was identified in 19 patients (median age, 11.8 years; range, 2.4 to 21.9 years) out of a total 302 female patients who underwent transplantation over an 8-year period at a pediatric HSCT center. The majority of patients had concomitant nongenital GVHD; only 1 patient had isolated vulvovaginal GVHD. The median time from bone marrow transplantation to diagnosis of vulvovaginal GVHD was 30 months (range, 2.3 to 97.5 months). A high percentage of the patients in our series were without vulvar or vaginal symptoms (n = 8; 42%), even though 17 patients (89%) presented with grade 3 disease based on current adult grading scales. Vulvar examination findings most frequently included interlabial and clitoral hood adhesions (89%), loss of architecture of the labia minora or clitoral hood (42%), and skin erosions or fissures (37%). Only 5 patients underwent a speculum exam, none of whom had vaginal GVHD. Examination findings of primary ovarian insufficiency (POI) can overlap with those of GVHD, and 6 patients (32%) in our cohort were diagnosed with POI. Only 1 patient was on systemic hormone replacement therapy at the time of vulvovaginal GVHD diagnosis. The majority of patients (n = 16) were treated with topical steroid therapy, with a median time to response of 43 days. Five patients (26%) had a complete response to therapy, and 10 patients (53%) had a partial response. This case series provides valuable insight into pediatric and young adult vulvovaginal GVHD and highlights the need for increased screening for vulvar disease in this population.

Xenon-129 MRI detects ventilation deficits in paediatric stem cell transplant patients unable to perform spirometry.

BACKGROUND: Early detection of pulmonary morbidity following haematopoietic stem cell transplantation (HSCT) remains an important challenge for intervention, primarily due to the insensitivity of spirometry to early change, and in paediatrics, patient compliance provides additional challenges. Regional lung ventilation abnormalities in paediatric HSCT patients were quantified using hyperpolarised xenon-129 (129Xe) magnetic resonance imaging (MRI) and compared to spirometry. METHODS: Medically stable, paediatric allogeneic HSCT patients (n=23, ages 6-16 years) underwent an outpatient MRI scan where regional ventilation was quantified with a breath-hold of hyperpolarised 129Xe gas. Ventilation deficits, regions of the lung that ventilate poorly due to obstruction, were quantified as a ventilation defect percentage (VDP) and compared to forced expiratory volume in 1 s (FEV1), FEV1/forced vital capacity (FVC) ratio, and forced expiratory flow at 25-75% of FVC (FEF25-75%) from spirometry using linear regression. RESULTS: The mean±sd 129Xe VDP was 10.5±9.4% (range 2.6-41.4%). 129Xe VDP correlated with FEV1, FEV1/FVC ratio and FEF25-75% (p≤0.02 for all comparisons). Ventilation deficits were detected in patients with normal spirometry (i.e. FEV1 >80%), supporting the sensitivity of 129Xe MRI to early obstruction reported in other pulmonary conditions. Seven (30%) patients could not perform spirometry, yet ventilation deficits were observed in five of these patients, detecting abnormalities that otherwise may have gone undetected and untreated until advanced. CONCLUSION: Lung ventilation deficits were detected using hyperpolarised 129Xe gas MRI in asymptomatic paediatric HSCT patients and in a subgroup who were unable to perform reliable spirometry. 129Xe MRI provides a reliable imaging-based assessment of pulmonary involvement in this potentially difficult to diagnose paediatric population.

Outcomes after bloodstream infection in hospitalized pediatric hematology/oncology and stem cell transplant patients.

BACKGROUND: Pediatric hematology/oncology (PHO) patients receiving therapy or undergoing hematopoietic stem cell transplantation (HSCT) often require a central line and are at risk for bloodstream infections (BSI). There are limited data describing outcomes of BSI in PHO and HSCT patients. METHODS: This is a multicenter (n = 17) retrospective analysis of outcomes of patients who developed a BSI. Centers involved participated in a quality improvement collaborative referred to as the Childhood Cancer and Blood Disorder Network within the Children's Hospital Association. The main outcome measures were all-cause mortality at 3, 10, and 30 days after positive culture date; transfer to the intensive care unit (ICU) within 48 hours of positive culture; and central line removal within seven days of the positive blood culture. RESULTS: Nine hundred fifty-seven BSI were included in the analysis. Three hundred fifty-four BSI (37%) were associated with at least one adverse outcome. All-cause mortality was 1% (n = 9), 3% (n = 26), and 6% (n = 57) at 3, 10, and 30 days after BSI, respectively. In the 165 BSI (17%) associated with admission to the ICU, the median ICU stay was four days (IQR 2-10). Twenty-one percent of all infections (n = 203) were associated with central line removal within seven days of positive blood culture. CONCLUSIONS: BSI in PHO and HSCT patients are associated with adverse outcomes. These data will assist in defining the impact of BSI in this population and demonstrate the need for quality improvement and research efforts to decrease them.

Treatment exposures stratify need for echocardiographic screening in asymptomatic long-term survivors of hematopoietic stem cell transplantation.

We sought to define the prevalence of echocardiographic abnormalities in long-term survivors of paediatric hematopoietic stem cell transplantation and determine the utility of screening in asymptomatic patients. We analysed echocardiograms performed on survivors who underwent hematopoietic stem cell transplantation from 1982 to 2006. A total of 389 patients were alive in 2017, with 114 having an echocardiogram obtained ⩾5 years post-infusion. A total of 95 patients had echocardiogram performed for routine surveillance. The mean time post-hematopoietic stem cell transplantation was 13 years. Of 95 patients, 77 (82.1%) had ejection fraction measured, and 10/77 (13.0%) had ejection fraction z-scores ⩽-2.0, which is abnormally low. Those patients with abnormal ejection fraction were significantly more likely to have been exposed to anthracyclines or total body irradiation. Among individuals who received neither anthracyclines nor total body irradiation, only 1/31 (3.2%) was found to have an abnormal ejection fraction of 51.4%, z-score -2.73. In the cohort of 77 patients, the negative predictive value of having a normal ejection fraction given no exposure to total body irradiation or anthracyclines was 96.7% at 95% confidence interval (83.3-99.8%). Systolic dysfunction is relatively common in long-term survivors of paediatric hematopoietic stem cell transplantation who have received anthracyclines or total body irradiation. Survivors who are asymptomatic and did not receive radiation or anthracyclines likely do not require surveillance echocardiograms, unless otherwise indicated.

Single Ultra-High-Dose Cholecalciferol to Prevent Vitamin D Deficiency in Pediatric Hematopoietic Stem Cell Transplantation.

Vitamin D deficiency is prevalent among childhood hematopoietic stem cell transplantation (HSCT) recipients and associated with inferior survival at 100 days after transplantation. Achieving and maintaining therapeutic vitamin D levels in HSCT recipients is extremely challenging in the first 3 to 6 months after transplantation due to poor compliance in the setting of mucositis and the concomitant use of critical transplantation drugs that interfere with vitamin D absorption. We sought to evaluate the safety and efficacy of a single, ultra-high-dose of vitamin D given before childhood HSCT to maintain levels in a therapeutic range during the peritransplantation period. Ten HSCT recipients with pretransplantation 25-OH vitamin D (25OHD) level <50 ng/mL and with no history of hypercalcemia, nephrolithiasis, or pathological fractures were enrolled on this pilot study. A single enteral vitamin D dose (maximum 600,000 IU) was administered to each patient based on weight and pretransplantation vitamin D level before the day of HSCT. Vitamin D levels between 30 and 150 ng/mL were considered therapeutic. All patients received close clinical observation and monitoring of 25OHD levels, calcium, phosphate, parathyroid hormone, urine calcium/creatinine ratio, and n-telopeptide for safety and efficacy assessment. The mean age of the study subjects was 5.8 ± 4.9 years, and the mean pretransplantation 25OHD level was 28.9 ± 13.1 ng/mL. All patients tolerated single, ultra-high-oral dose of vitamin D under direct medical supervision. No other oral vitamin D supplements were administered during the observation window of 8 weeks. Three of 10 patients received 400 IU/day of vitamin D in parenteral nutrition only for 5 days during the study window. A mean peak serum vitamin D level of 80.4 ± 28.6 ng/mL was reached at a median of 9 days after the vitamin D dose. All patients achieved a therapeutic vitamin D level of >30 ng/mL. Mean vitamin D levels were sustained at or above 30 ng/mL during the 8-week observation window. There were no electrolyte abnormalities attributed to the ultra-high-dose of vitamin D. Most patients had mildly elevated urine calcium/creatinine ratios during treatment, but none showed clinical or radiologic signs of nephrocalcinosis or nephrolithiasis. Our findings indicate that single ultra-high-oral dose vitamin D treatment given just before HSCT is safe and well tolerated in the immediate peritransplant period in children. Patients in our study were able to achieve and sustain therapeutic vitamin D levels throughout the critical period during which vitamin D insufficiency is associated with decreased overall survival. Larger prospective studies are needed to address the impact of single ultra-high-dose vitamin D treatment on HSCT outcomes.

Multiple bloodstream infections in pediatric stem cell transplant recipients: A case series.

Bacterial bloodstream infections (BSIs) are associated with poor outcomes following stem cell transplantation (SCT). We describe the demographics, treatment, complications, and outcome of 23 pediatric SCT recipients who developed three or more BSIs in the first year after SCT at our center from 2011 through 2016. The majority underwent allogeneic SCT (n = 22/23;96%), mainly from an unrelated donor (n = 19/22,86%); developed grade 2-4 graft versus host disease (GVHD; n = 14/23, 61%), all steroid refractory; and were diagnosed with thrombotic microangiopathy (n = 21/23, 91%). One-year overall survival was 56% (n = 13/23). We observed a high rate of transplant-associated thrombotic microangiopathy and steroid-refractory acute GVHD in patients with three or more BSIs.

Oral health and hematopoietic stem cell transplantation: A longitudinal evaluation of the first 28 days.

BACKGROUND: Mucositis is well described after pediatric hematopoietic stem cell transplant (HSCT) but other aspects of oral health such as dental plaque and gingivitis are poorly understood. The aim of this study was to describe dental plaque, gingivitis, and mucositis early after HSCT. METHODS: We conducted a prospective longitudinal observational study to describe dental plaque, gingivitis, and mucositis in the peritransplant period. We conducted comprehensive oral evaluations that included the Miyazaki tongue coating, modified simplified oral hygiene, modified gingivitis of Suomi and Barbano, and mucosal ulceration indices at baseline on days 0, +7, +14, and +28. RESULTS: Data were collected from 19 patients with a median age of 8.0 years (5.1-12.8) at time of HSCT. Sixteen patients (85%) had plaque accumulation that progressively worsened, 16 (85%) developed severe gingival inflammation, 13 (68%) developed mucositis, and 11 (58%) had oral ulcerations. All oral indices worsened from baseline during the study period. Gingivitis and oral plaque persisted in most patients at day +28 while mucositis and oral ulcerations slightly improved. DISCUSSION: Gingivitis, dental plaque, mucositis, and oral ulcerations are common after HSCT. Additional studies are needed to ascertain methods that decrease plaque and gingivitis development and severity.

Ruxolitinib as Salvage Therapy in Steroid-Refractory Acute Graft-versus-Host Disease in Pediatric Hematopoietic Stem Cell Transplant Patients.

We describe our retrospective clinical experience with ruxolitinib for steroid-refractory acute graft-versus-host disease (GVHD) in pediatric allogeneic hematopoietic stem cell transplant (HSCT) patients. Ruxolitinib was administered orally at 5 mg twice daily for children ≥ 25 kg or 2.5 mg twice daily if <25 kg. We excluded patients who received new immune suppressive agents within 2 weeks before initiation of ruxolitinib from response analysis. Patients were called a treatment failure if ruxolitinib was stopped before completion of 4 weeks of therapy because of adverse effects and not because of progression of acute GVHD. Thirteen patients received ruxolitinib, and 11 patients were assessable for response. One patient achieved a complete response, 4 had a partial response, and 2 had no response at 4 weeks after the first ruxolitinib dose. Four patients were treatment failures. Overall response rate was 45%. Adverse effects (n = 13) included grades 3 to 4 elevated alanine transaminase (n = 7), grades 3 to 4 neutropenia (n = 5), and grade 4 thrombocytopenia (n = 3). Infectious complications in patients included for response analysis (n = 11) were Epstein-Barr viremia (n = 2), adenovirus (n = 2), BK (n = 3), bacterial infections (n = 6), and fungal infections (n = 1). Seven of 13 patients were alive at a median follow-up of 401 days (range, 219 to 969) after HSCT. We observed a high rate of reversible adverse effects in children with steroid-refractory acute GVHD and a fair overall response of ruxolitinib as a salvage therapeutic agent. Further pharmacokinetic studies are needed to determine the best-tolerated dose of ruxolitinib that will achieve efficacy without significant adverse effects.

Cardiotoxicity and cardiomyopathy in children and young adult survivors of hematopoietic stem cell transplant.

Cardiomyopathy is common in long-term survivors of pediatric hematopoietic stem cell transplant (HSCT). Events occurring before and after HSCT when combined with specific insults during HSCT likely contribute to long-term risk. Strategies for detecting subclinical cardiomyopathy prior to patients developing overt heart failure are under investigation. Changes in HSCT preparative regimens and cardioprotective medications administered during chemotherapy may alter the risk for cardiomyopathy. Interventions in long-term survivors such as lifestyle modification and cardioactive medications are of increasing importance. Herein we review the causes of cardiac injury, discuss strategies for detection of cardiomyopathy, and evaluate therapeutic options for long-term HSCT survivors.

Team-based approach to identify cardiac toxicity in critically ill hematopoietic stem cell transplant recipients.

INTRODUCTION: We observed pulmonary hypertension (PH), pericardial effusions, and left ventricular systolic dysfunction (LVSD) in multiple critically ill hematopoietic stem cell transplant (HSCT) recipients. We implemented routine structured echocardiography screening for HSCT recipients admitted to the pediatric intensive care unit (PICU) using a standardized multidisciplinary process. METHODS: HSCT recipients admitted to the PICU with respiratory distress, hypoxia, shock, and complications related to transplant-associated thrombotic microangiopathy were screened on admission and every 1-2 weeks thereafter. Echocardiography findings requiring intervention and/or further screening included elevated right ventricular pressure, LVSD, and moderate to large pericardial effusions. All echocardiograms were compared to the patient's routine pretransplant echocardiogram. RESULTS: Seventy HSCT recipients required echocardiography screening over a 3-year period. Echo abnormalities requiring intervention and/or further screening were found in 35 (50%) patients. Twenty-four (34%) patients were noted to have elevated right ventricular pressure; 14 (20%) were at risk for PH, while 10 (14%) had PH. All patients with PH were treated with pulmonary vasodilators. LVSD was noted in 22 (31%) patients; 15/22 (68%) received inotropic support. Moderate to large pericardial effusions were present in nine (13%) patients, with six needing pericardial drain placement. DISCUSSION: Echocardiographic abnormalities are common in critically ill HSCT recipients. Utilization of echocardiogram screening may allow for early detection and timely intervention for cardiac complications in this high-risk cohort.

Restrictive Palivizumab Use Does Not Lead to Increased Morbidity and Mortality in Pediatric Hematopoietic Stem Cell Transplantation Patients.

Respiratory syncytial virus (RSV) is a common cause of infection in immunocompromised patients and can lead to significant morbidity and mortality in pediatric hematopoietic stem cell transplantation (HSCT) patients and patients with a primary immune deficiency (PID). Palivizumab is a humanized monoclonal antibody that targets the F glycoprotein on the surface of the RSV virus, preventing RSV replication. Palivizumab was initially licensed for the prevention of RSV infections in children at high risk of severe disease. Since licensure, the American Academy of Pediatrics (AAP) has issued guidelines to help ensure appropriate use of palivizumab in pediatric patients. In the 2014 edition of the guidelines, the AAP recognizes that severe and fatal disease secondary to RSV can be seen in patients receiving chemotherapy or patients who are immunocompromised because of other conditions. However, they recognize that no large clinical trials exist to support the use of palivizumab, and efficacy and safety data in this population are limited. Despite this, the AAP recommends considering prophylaxis for children younger than 24 months who are profoundly immunocompromised during the RSV season. Because of the high cost of palivizumab, the uncertainty of its efficacy as prophylaxis in hospitalized pediatric HSCT and PID patients, and secondary to recent data from our center that suggested immunocompromised patients diagnosed with RSV did not have worse outcomes, we implemented very restrictive criteria for the use of palivizumab in the 2015 to 2016 RSV season in our pediatric HSCT population. Despite these strict criteria, there was no change in the number of patients developing RSV during this season compared with previous seasons, and there was no change in RSV course in those patients developing RSV compared with previous seasons. Restricted use also resulted in a significant dose and cost savings. Based on our experience, we recommend only administering prophylaxis palivizumab to the youngest and most high-risk HSCT patients during the RSV season.

Terminal Complement Blockade after Hematopoietic Stem Cell Transplantation Is Safe without Meningococcal Vaccination.

Eculizumab inhibits terminal complement-mediated intravascular hemolysis in patients with paroxysmal nocturnal hemoglobinuria and complement-mediated thrombotic microangiopathy (TMA) in patients with atypical hemolytic uremic syndrome and is now used as a first-line therapy in these diseases. Eculizumab is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) because of an increased risk of meningococcal infections in persons without adequate functional complement. Administration of meningococcal vaccine is required at least 2 weeks before administering the first dose of eculizumab, and this advice is included in the product label. Eculizumab use for treatment of TMA in hematopoietic stem cell transplantation (HSCT) recipients brings a significant dilemma regarding REMS required meningococcal vaccination. TMA after HSCT usually occurs within the first 100 days after transplantation when patients are severely immunocompromised and are not able to mount a response to vaccines. We evaluated 30 HSCT recipients treated with eculizumab for high-risk TMA without meningococcal vaccine. All patients received antimicrobial prophylaxis adequate for Neisseria meningitides during eculizumab therapy and for 8 weeks after discontinuation of the drug. Median time to TMA diagnosis was 28 days after transplant (range, 13.8 to 48.5). Study subjects received a median of 14 eculizumab doses (range, 2 to 38 doses) for HSCT-associated TMA therapy. There were no incidences of meningococcal infections. The incidences of bacterial and fungal bloodstream infections were similar in patients treated with eculizumab (n = 30) as compared with those with HSCT-associated TMA who did not receive any complement blocking therapy (n = 39). Our data indicate that terminal complement blockade in the early post-transplant period can be performed without meningococcal vaccination while using appropriate antimicrobial prophylaxis until complement function is restored after therapy completion.

Healthcare Burden, Risk Factors, and Outcomes of Mucosal Barrier Injury Laboratory-Confirmed Bloodstream Infections after Stem Cell Transplantation.

Mucosal barrier injury laboratory-confirmed bloodstream infections (MBI-LCBIs) lead to significant morbidity, mortality, and healthcare resource utilization in hematopoietic stem cell transplant (HSCT) patients. Determination of the healthcare burden of MBI-LCBIs and identification of patients at risk of MBI-LCBIs will allow researchers to identify strategies to reduce MBI-LCBI rates. The objective of our study was to describe the incidence, risk factors, timing, and outcomes of MBI-LCBIs in hematopoietic stem cell transplant patients. We performed a retrospective analysis of 374 patients who underwent HSCT at a large free-standing academic children's hospital to determine the incidence, risk factors, and outcomes of patients that developed a bloodstream infection (BSI) including MBI-LCBI, central line-associated BSI (CLABSI), or secondary BSI in the first year after HSCT. Outcome measures included nonrelapse mortality (NRM), central venous catheter removal within 7 days of positive culture, shock, admission to the pediatric intensive care unit (PICU) within 48 hours of positive culture, and death within 10 days of positive culture. One hundred seventy BSIs were diagnosed in 100 patients (27%): 80 (47%) MBI-LCBIs, 68 (40%) CLABSIs, and 22 (13%) secondary infections. MBI-LCBIs were diagnosed at a significantly higher rate in allogeneic HSCT patients (18% versus 7%, P = .007). Reduced-intensity conditioning (OR, 1.96; P = .015) and transplant-associated thrombotic microangiopathy (OR, 2.94; P = .0004) were associated with MBI-LCBI. Nearly 50% of all patients with a BSI developed septic shock, 10% died within 10 days of positive culture, and nearly 25% were transferred to the PICU. One-year NRM was significantly increased in patients with 1 (34%) and more than 1 (56%) BSIs in the first year post-HSCT compared with those who did not develop BSIs (14%) (P ≤ .0001). There was increased 1-year NRM in patients with at least 1 MBI-LCBI (OR, 1.94; P = .018) and at least 1 secondary BSI (OR, 2.87; P = .0023) but not CLABSIs (OR, 1.17; P = .68). Our data demonstrate that MBI-LCBIs lead to substantial use of healthcare resources and are associated with significant morbidity and mortality. Reduction in frequency of MBI-LCBI should be a major public health and scientific priority.

Vitamin D Deficiency in Pediatric Hematopoietic Stem Cell Transplantation Patients Despite Both Standard and Aggressive Supplementation.

We recently reported that more than 70% of pediatric and young adult patients had a vitamin D (VD) deficiency at the time of their hematopoietic stem cell transplantation (HSCT). Moreover, VD deficiency was associated with inferior survival at 100 days after transplantation. The goal of the present study was to evaluate the VD requirements needed to maintain an optimal VD level (30 to 60 ng/mL) during the first 3 months after transplantation using real-time VD monitoring and personalized VD supplementation. We examined 2 cohorts in this study: cohort 1, the "preintervention" cohort (n = 35), who were treated according to National Kidney Foundation guidelines for VD therapy, and cohort 2, the "intervention" cohort (n = 25) who were treated with high-dose VD with an aggressive dosage increase in those who remained VD-insufficient. Results from cohort 1 showed that despite aggressive monitoring and VD supplementation, therapeutic vitamin D levels were difficult to achieve and maintain in HSCT recipients during the early post-transplantation period. Only 43% of cohort 1 achieved a therapeutic VD level, leading to our intervention in cohort 2. Outcomes improved in cohort 2, but still only 64% of cohort 2 patients achieved a therapeutic VD level despite receiving >200 IU/kg/day of VD enterally. The median VD level in patients who did achieve sufficient levels was 40 ng/mL, with only 1 patient in each cohort achieving a supratherapeutic but nontoxic level. These data indicate that standard guidelines for VD replacement are inadequate in HSCT recipients, and further work is needed to define more appropriate dosing in this clinical setting.

A Prospective Study of Alemtuzumab as a Second-Line Agent for Steroid-Refractory Acute Graft-versus-Host Disease in Pediatric and Young Adult Allogeneic Hematopoietic Stem Cell Transplantation.

We describe a single-center prospective study of alemtuzumab as a second-line agent for steroid-refractory (SR) acute graft-versus-host disease (aGVHD) in pediatric and young adult allogeneic hematopoietic stem cell transplant recipients. Alemtuzumab was administered for grades II to IV aGVHD if patients did not improve within 5 days or worsened within 48 hours after corticosteroids. Interim analyses of alemtuzumab levels and response were performed after every 5 patients enrolled, resulting in 3 dosing cohorts, as follows: (1) .2 mg/kg alemtuzumab subcutaneously on days 1 to 5 (maximum of 31 mg over 5 days) and .2 mg/kg/dose (not exceeding 10 mg/dose) on days 15, 22, and 29; (2) .2 mg/kg alemtuzumab subcutaneously on days 1 to 5 (maximum of 43 mg over 5 days) and .2 mg/kg/dose on day 7, 10, 15, 22, and 29; and (3) .2 mg/kg subcutaneously on days 1 to 5 and .2 mg/kg/dose on day 7, 10, 15, and 22. Alemtuzumab levels were assessed before starting alemtuzumab and at days 1, 3, 6, 10, and 14 and weekly until day 99, where day 1 was the day of first alemtuzumab dose. Fifteen patients (median age, 10 years; range, 1.4 to 27) received alemtuzumab for grades II (6%), III (74%), and IV (20%) SR-aGVHD. The overall response rate was 67%, with complete response (CR) in 40%, partial response (PR) in 27%, and no response in 33%. The median day 6 alemtuzumab level was 2.79 µg/mL (interquartile range, 1.34 to 4.89) in patients with CR compared with .62 µg/mL (interquartile range, .25 to 1.45) in patients with PR + no response (P < .05). Ninety percent (n = 9) of patients with a CR or PR reduced corticosteroid doses within 8 weeks from first alemtuzumab dose. Side effects included fever (26%) and transient thrombocytopenia (53%). Asymptomatic viremias occurred in all patients but invasive viral disease occurred in 2 patients. One patient developed Epstein-Barr virus-post-transplantation lymphoproliferative disorder. Eighty percent (n = 12) of patients were alive at 6 months, of whom 53% (n = 8) were free of GVHD whereas 13% (n = 2) developed chronic GVHD. Alemtuzumab is an effective second-line agent for children and young adults with SR-aGVHD. Higher alemtuzumab levels are associated with CR. A real-time dose adjusted alemtuzumab study is needed to further optimize the dose of alemtuzumab in aGVHD.

Diagnostic and risk criteria for HSCT-associated thrombotic microangiopathy: a study in children and young adults.

Transplant-associated thrombotic microangiopathy (TMA) leads to generalized endothelial dysfunction that can progress to multiorgan injury, and severe cases are associated with poor outcomes after hematopoietic stem cell transplantation (HSCT). Identifying patients at highest risk for severe disease is challenging. We prospectively evaluated 100 consecutive HSCT recipients to determine the incidence of moderate and severe TMA and factors associated with poor overall outcomes. Thirty-nine subjects (39%) met previously published criteria for TMA. Subjects with TMA had a significantly higher nonrelapse mortality (43.6% vs 7.8%, P < .0001) at 1 year post-HSCT compared with those without TMA. Elevated lactate dehydrogenase, proteinuria on routine urinalysis, and hypertension were the earliest markers of TMA. Proteinuria (>30 mg/dL) and evidence of terminal complement activation (elevated sC5b-9) in the blood at the time of TMA diagnosis were associated with very poor survival (<20% at 1 year), whereas all TMA subjects without proteinuria and a normal sC5b-9 serum concentration survived (P < .01). Based on these prospective observations, we conclude that severe TMA occurred in 18% of HSCT recipients in our cohort and propose an algorithm to identify the highest-risk patients who might benefit from prompt clinical interventions.

New approaches in the diagnosis, pathophysiology, and treatment of pediatric hematopoietic stem cell transplantation-associated thrombotic microangiopathy.

Hematopoietic stem cell transplantation (HSCT)-associated thrombotic microangiopathy (TA-TMA) is an understudied complication of HSCT that significantly affects transplant-related morbidity and mortality. Over the past several decades, the cause of TA-TMA has remained unknown, limiting treatment options to non-specific therapies adapted from other diseases. Recent prospective studies dedicated to the study of TA-TMA have provided new insights into the pathogenesis of, and genetic susceptibility to TA-TMA, raising awareness of this important transplant complication and allowing for the identification of potentially novel therapeutic targets. Specifically, many patients with TA-TMA develop multi-organ tissue injury through endothelial damage mediated by the activation of the complement pathway, leading to rational therapeutic strategies including complement blockade. This new knowledge has the potential to favorably influence clinical practice and change the standard of care for how patients with TA-TMA are managed. In this review, we summarize novel approaches to the recognition and management of TA-TMA, using case examples to illustrate key clinical points that hopefully lead to improved short and long-term outcomes for these complex HSCT patients, who remain at significant risk for treatment-related morbidity and mortality.

Veno-occlusive disease of the liver in the absence of elevation in bilirubin in pediatric patients after hematopoietic stem cell transplantation.

Veno-occlusive disease (VOD) of the liver is a well-described and significant complication of hematopoietic stem cell transplantation (HSCT), with limited successful therapeutic options in severe cases. Prompt diagnosis and initiation of treatment is crucial to restrict the extent of disease. However, a subset of patients may not meet all current diagnostic criteria at presentation, and waiting for these to be met may delay therapy. We retrospectively reviewed 794 HSCT patients treated at our institution between 2003 and 2013, identifying 17 (2.1%) who developed VOD. Of these, 5 (29%) were noted to have an absence of elevated bilirubin at the time of VOD diagnosis and reversal of portal venous flow on ultrasound. Median total and conjugated bilirubin at VOD diagnosis were 1.0 and 0.2 mg/dL, respectively. All 5 patients were subsequently diagnosed with multiorgan failure associated with VOD, including 1 with encephalopathy. Four were treated with intravenous high-dose methylprednisolone (500 mg/m(2) per dose every 12 hours for 6 doses). One patient received defibrotide therapy in addition to steroids and another supportive care alone. VOD resolved in 4 of 5 patients, with median time to resolution of VOD, defined as recovery of all organ function and normalization of bilirubin and portal venous flow, of 8 days. Two patients died later from progressive primary disease and chronic graft-versus-host disease, respectively. We conclude that a high index of suspicion for VOD should be maintained in patients despite lack of bilirubin elevation in the presence of other diagnostic criteria such as hepatomegaly, abdominal pain, ascites, or weight gain. Early ultrasound evaluation in these patients may lead to more timely diagnosis and therapeutic interventions.

Histologic Features of Intestinal Thrombotic Microangiopathy in Pediatric and Young Adult Patients after Hematopoietic Stem Cell Transplantation.

High-risk transplantation-associated thrombotic microangiopathy (TMA) can present with multisystem involvement and is associated with a poor outcome after hematopoietic stem cell transplantation (HSCT), with < 20% 1-year survival. TMA may involve the intestinal vasculature and can present with bleeding and ischemic colitis. There are no established pathologic criteria for the diagnosis of intestinal TMA (iTMA). The goal of our study was to identify histologic features of iTMA and describe associated clinical features. We evaluated endoscopic samples from 50 consecutive HSCT patients for 8 histopathologic signs of iTMA and compared findings in 3 clinical groups based on the presence or absence of systemic high-risk TMA (hrTMA) and the presence or absence of clinically staged intestinal graft-versus-host disease (iGVHD): TMA/iGVHD, no TMA/iGVHD, and no TMA/no iGVHD. Thirty percent of the study subjects had a clinical diagnosis of systemic hrTMA. On histology, loss of glands, intraluminal schistocytes, intraluminal fibrin, intraluminal microthrombi, endothelial cell separation, and total denudation of mucosa were significantly more common in the hrTMA group (P < .05). Intravascular thrombi were seen exclusively in patients with hrTMA. Mucosal hemorrhages and endothelial cell swelling were more common in hrTMA patients but this difference did not reach statistical significance. Patients with hrTMA were more likely to experience significant abdominal pain and gastrointestinal bleeding requiring multiple blood transfusions (P < .05). Our study shows that HSCT patients with systemic hrTMA can have significant bowel vascular injury that can be identified using defined histologic criteria. Recognition of these histologic signs in post-transplantation patients with significant gastrointestinal symptoms may guide clinical decisions.

Clinical Utility of Computed Tomography and Magnetic Resonance Imaging for Diagnosis of Posterior Reversible Encephalopathy Syndrome after Stem Cell Transplantation in Children and Adolescents.

Posterior reversible encephalopathy syndrome (PRES) is a clinical syndrome characterized by vision changes, altered mental status, and seizures, typically caused by an acute rise in blood pressure. PRES has been reported after hematopoietic stem cell transplantation (HSCT) in association with hypertension from calcineurin inhibitors and corticosteroids. The imaging evaluation of PRES after HSCT in children and young adults has not been well described. We performed a retrospective review of all HSCT recipients presenting to the intensive care unit with new neurologic symptoms. A neuroradiologist reviewed all radiologic images and compared computed tomography (CT) versus magnetic resonance imaging (MRI) findings indicative of diagnosis of PRES. Alternative imaging diagnoses explaining the patients' symptoms were also recorded. Fifty-four transplant recipients were admitted to the intensive care unit with new neurologic symptoms. Thirty-nine percent (21 of 54) of subjects had imaging findings consistent with PRES, 24% (13 of 54) had imaging findings consistent with an alternative diagnosis, 9% (5 of 54) had a nonspecific finding, and 28% (15 of 54) had no acute imaging findings. PRES was diagnosed at a median of 49 days (interquartile range, 29 to 94) after HSCT. The presenting symptom for the majority of patients with PRES was seizures (86%), whereas 14% presented with acute encephalopathy. Ninety-five percent of subjects diagnosed with PRES (20 of 21) underwent a head CT as their initial imaging evaluation. CT scan was diagnostic of PRES in 40% (8 of 20). Subsequently, 16 patients underwent brain MRI with 12 additional patients being diagnosed with PRES on MRI. The median time elapsed between negative CT and a positive MRI examination was 20 hours (range, 3.6 hours to 9 days). CT serves as an excellent screening test for acute pathology, such as intracranial hemorrhage; however, it lacks sensitivity for the diagnosis of PRES. Patients with clinical symptoms suggestive of PRES who have a negative CT should be treated appropriately for PRES and should undergo MRI of the brain as soon as clinically stable to confirm the diagnosis.