Harmonizing Definitions for Diagnostic Criteria and Prognostic Assessment of Transplantation-Associated Thrombotic Microangiopathy: A Report on Behalf of the European Society for Blood and Marrow Transplantation, American Society for Transplantation and Cellular Therapy, Asia-Pacific Blood and Marrow Transplantation Group, and Center for International Blood and Marrow Transplant Research.

Transplantation-associated thrombotic microangiopathy (TA-TMA) is an increasingly recognized complication of hematopoietic cell transplantation (HCT) associated with significant morbidity and mortality. However, TA-TMA is a clinical diagnosis, and multiple criteria have been proposed without universal application. Although some patients have a self-resolving disease, others progress to multiorgan failure and/or death. Poor prognostic features also are not uniformly accepted. The lack of harmonization of diagnostic and prognostic markers has precluded multi-institutional studies to better understand incidence and outcomes. Even current interventional trials use different criteria, making it challenging to interpret the data. To address this urgent need, the American Society for Transplantation and Cellular Therapy, Center for International Bone Marrow Transplant Research, Asia-Pacific Blood and Marrow Transplantation, and European Society for Blood and Marrow Transplantation nominated representatives for an expert panel tasked with reaching consensus on diagnostic and prognostic criteria. The panel reviewed literature, generated consensus statements regarding diagnostic and prognostic features of TA-TMA using the Delphi method, and identified future directions of investigation. Consensus was reached on 4 key concepts: (1) TA-TMA can be diagnosed using clinical and laboratory criteria or tissue biopsy of kidney or gastrointestinal tissue; however, biopsy is not required; (2) consensus diagnostic criteria are proposed using the modified Jodele criteria with additional definitions of anemia and thrombocytopenia. TA-TMA is diagnosed when ≥4 of the following 7 features occur twice within 14 days: anemia, defined as failure to achieve transfusion independence despite neutrophil engraftment; hemoglobin decline by ≥1 g/dL or new-onset transfusion dependence; thrombocytopenia, defined as failure to achieve platelet engraftment, higher-than-expected transfusion needs, refractory to platelet transfusions, or ≥50% reduction in baseline platelet count after full platelet engraftment; lactate dehydrogenase (LDH) exceeding the upper limit of normal (ULN); schistocytes; hypertension; soluble C5b-9 (sC5b-9) exceeding the ULN; and proteinuria (≥1 mg/mg random urine protein-to-creatinine ratio [rUPCR]); (3) patients with any of the following features are at increased risk of nonrelapse mortality and should be stratified as high-risk TA-TMA: elevated sC5b-9, LDH ≥2 times the ULN, rUPCR ≥1 mg/mg, multiorgan dysfunction, concurrent grade II-IV acute graft-versus-host disease (GVHD), or infection (bacterial or viral); and (4) all allogeneic and pediatric autologous HCT recipients with neuroblastoma should be screened weekly for TA-TMA during the first 100 days post-HCT. Patients diagnosed with TA-TMA should be risk-stratified, and those with high-risk disease should be offered participation in a clinical trial for TA-TMA-directed therapy if available. We propose that these criteria and risk stratification features be used in data registries, prospective studies, and clinical practice across international settings. This harmonization will facilitate the investigation of TA-TMA across populations diverse in race, ethnicity, age, disease indications, and transplantation characteristics. As these criteria are widely used, we expect continued refinement as necessary. Efforts to identify more specific diagnostic and prognostic biomarkers are a top priority of the field. Finally, an investigation of the impact of TA-TMA-directed treatment, particularly in the setting of concurrent highly morbid complications, such as steroid-refractory GVHD and infection, is critically needed.

Outcomes following autologous hematopoietic stem cell transplant for patients with relapsed Wilms' tumor: a CIBMTR retrospective analysis.

Despite the marked improvement in the overall survival (OS) for patients diagnosed with Wilms' tumor (WT), the outcomes for those who experience relapse have remained disappointing. We describe the outcomes of 253 patients with relapsed WT who received high-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplant (HCT) between 1990 and 2013, and were reported to the Center for International Blood and Marrow Transplantation Research. The 5-year estimates for event-free survival (EFS) and OS were 36% (95% confidence interval (CI); 29-43%) and 45% (95 CI; 38-51%), respectively. Relapse of primary disease was the cause of death in 81% of the population. EFS, OS, relapse and transplant-related mortality showed no significant differences when broken down by disease status at transplant, time from diagnosis to transplant, year of transplant or conditioning regimen. Our data suggest that HDT followed by autologous HCT for relapsed WT is well tolerated and outcomes are similar to those reported in the literature. As attempts to conduct a randomized trial comparing maintenance chemotherapy with consolidation versus HDT followed by stem cell transplant have failed, one should balance the potential benefits with the yet unknown long-term risks. As disease recurrence continues to be the most common cause of death, future research should focus on the development of consolidation therapies for those patients achieving complete response to therapy.

Long-term systolic function in children and young adults after hematopoietic stem cell transplant.

Congestive heart failure and subclinical left ventricular systolic dysfunction (LVSD) affect long-term survivors of hematopoietic stem cell transplant (HSCT). Echocardiographic measurements of global longitudinal and circumferential strain have shown promise in identifying subclinical LVSD in cancer survivors. We analyzed echocardiograms in 95 children and young adults with malignancies or bone marrow failure syndromes performed before HSCT and 1-6 years after HSCT. We additionally measured the biomarkers soluble suppression of tumorigenicity-2 (sST-2) and cardiac troponin-I (cTn-I) in the same children through 49 days post HSCT. Ejection fraction (EF) after HSCT was unchanged from baseline (baseline: z-score -0.73 vs long-term follow up: -0.44, P=0.11). Global longitudinal strain was unchanged from baseline (-20.66 vs -20.74%, P=0.90) as was global circumferential strain (-24.3 vs -23.5%, P=0.32). Levels of sST-2 were elevated at all time points compared with baseline samples and cTn-I was elevated at days 14 and 28. Cardiac biomarkers at any time point did not correlate with long-term follow-up EF. In children and young adult survivors of HSCT, EF was unchanged in the first years after HSCT. Elevation in cardiac biomarkers occurring after HSCT suggest subclinical cardiac injury occurs in many patients and long-term monitoring for LVSD should continue.

The injured heart: early cardiac effects of hematopoietic stem cell transplantation in children and young adults.

We hypothesized that subclinical cardiac injury in the peri-transplant period is more frequent than currently appreciated in children and young adults. We performed echocardiographic screening on 227 consecutive patients prior to hematopoietic stem cell transplantation (HSCT), and 7, 30 and 100 days after transplant. We measured cardiac biomarkers cardiac troponin-I (cTn-I), and soluble suppressor of tumorigenicity 2 (sST2) prior to transplant, during conditioning, and days +7, +14, +28 and +49 in 26 patients. We subsequently analyzed levels of cTn-I every 48-72 h in 15 consecutive children during conditioning. Thirty-two percent (73/227) of patients had a new abnormality on echocardiogram. New left ventricular systolic dysfunction (LVSD) occurred in 6.2% of subjects and new pericardial effusion in 27.3%. Eight of 227 (3.5%) patients underwent pericardial drain placement, and 5 (2.2%) received medical therapy for clinically occult LVSD. cTn-I was elevated in 53.0% of all samples and sST2 in 38.2%. At least one sample had a detectable cTn-I in 84.6% of patients and an elevated sST2 in 76.9%. Thirteen of fifteen patients monitored frequently during condition had elevation of cTn-I. Echocardiographic and biochemical abnormalities are frequent in the peri-HSCT period. Echocardiogram does not detect all subclinical cardiac injuries that may become clinically relevant over longer periods.

Poor growth, thyroid dysfunction and vitamin D deficiency remain prevalent despite reduced intensity chemotherapy for hematopoietic stem cell transplantation in children and young adults.

Myeloablative conditioning regimens for hematopoietic stem cell transplant (HSCT) are known to affect endocrine function, but little is known regarding reduced intensity conditioning (RIC) regimens. We retrospectively reviewed 114 children and young adults after single RIC HSCT. The analysis was grouped by age (<2 and ⩾2 years) and diagnosis (hemophagocytic lymphohistiocystosis/X-linked lymphoproliferative syndrome (HLH/XLP), other immune disorders, metabolic/genetic disorders). All groups displayed short stature by mean height-adjusted Z-score (HAZ) before (-1.29) and after HSCT (HAZ -1.38, P=0.47). After HSCT, younger children with HLH/XLP grew better (HAZ -3.41 vs -1.65, P=0.006), whereas older subjects had decline in growth (HAZ -0.8 vs -1.01, P=0.06). Those with steroid therapy beyond standard GVHD prophylaxis were shorter than those without (P 0.04). After HSCT, older subjects with HLH/XLP became thinner with a mean body mass index (BMI) Z-score of 1.20 vs 0.64, P=0.02, and similar to metabolic/genetic disorders (BMI-Z= 0.59 vs -0.99, P<0.001). BMI increased among younger children in these same groups. Thyroid function was abnormal in 24% (18/76). 25-OH vitamin D levels were insufficient in 73% (49/65), with low bone mineral density in 8 of 19 evaluable subjects. Despite RIC, children and young adults still have significant late endocrine effects. Further research is required to compare post-transplant endocrine effects after RIC to those after standard chemotherapy protocols.

Allogeneic hematopoietic cell transplantation for neuroblastoma: the CIBMTR experience.

Although the role of autologous hematopoietic cell transplantation (auto-HCT) is well established in neuroblastoma (NBL), the role of allogeneic HCT (allo-HCT) is controversial. The Center for International Blood and Marrow Transplant Research conducted a retrospective review of 143 allo-HCT for NBL reported in 1990-2007. Patients were categorized into two different groups: those who had not (Group 1) and had (Group 2) undergone a prior auto-HCT (n=46 and 97, respectively). One-year and five-year OS were 59% and 29% for Group 1 and 50% and 7% for Group 2, respectively. Among donor types, disease-free survival (DFS) and OS were significantly lower for unrelated transplants at 1 and 3 years but not at 5 years post HCT. Patients in CR or very good partial response (VGPR) at transplant had lower relapse rates and better DFS and OS, compared with those not in CR or VGPR. Our analysis indicates that allo-HCT can cure some neuroblastoma patients, with lower relapse rates and improved survival in patients without a history of prior auto-HCT as compared with those patients who had previously undergone auto-HCT. Although the data do not address why either strategy was chosen for patients, allo-HCT after a prior auto-HCT appears to offer minimal benefit. Disease recurrence remains the most common cause of treatment failure.

Outcomes following hematopoietic cell transplantation for Wiskott-Aldrich syndrome.

HLA-identical sibling donor transplantation remains the treatment of choice for Wiskott-Aldrich Syndrome (WAS). Since 1990, utilization of alternative donor sources has increased significantly. We report the hematopoietic cell transplantation (HCT) outcomes of 47 patients with WAS treated at a single center since 1990. Improved outcomes were observed after 2000 despite the increased number of alternative donors. Five-year OS improved from 62.5% (95% CI: 34.9% to 81.1%) to 90.8% (95% CI: 67.7% to 97.6%) for patients transplanted during 1990-2000 and 2001-2009, respectively. In multivariate analysis, transplant era significantly impacted OS (P=0.04), whereas age was only marginally significant (P=0.06, Cox proportional hazard analysis). No TRM occurred within the first 100 days among patients transplanted during 2001-2009 compared with 3/16 during 1990-2000, (P=0.03, Fisher's exact test). The extent of HLA mismatch did not significantly affect the incidence of acute GVHD, chronic GVHD or survival. Post-HCT autoimmune cytopenias were frequently diagnosed after 2001: 17/31 (55%) patients. Their occurrence was not associated with transplant donor type (P=0.53), acute GVHD (P=0.74), chronic GVHD (P=0.12), or post-transplant mixed chimerism (P=0.50).

Early clinical indicators of transplant-associated thrombotic microangiopathy in pediatric neuroblastoma patients undergoing auto-SCT.

Patients undergoing auto-SCT for neuroblastoma present a unique population to study transplant-associated thrombotic microangiopathy (TA-TMA), due to standardized chemotherapy and later exposure to radiation and cis-retinoic acid (cis-RA). We retrospectively analyzed 20 patients after auto-SCT to evaluate early clinical indicators of TA-TMA. A total of 6 patients developing TA-TMA (30% prevalence) were compared with 14 controls. Four of six patients were diagnosed with TA-TMA by 25 days after auto-SCT. Compared with controls, TA-TMA patients had higher average systolic and diastolic blood pressure levels during high-dose chemotherapy and developed hypertension by day 13 after auto-SCT. Proteinuria was a significant marker for TA-TMA, whereas blood and platelet transfusion requirements were not. Serum creatinine did not differ between groups post transplant. However, patients with TA-TMA had a 60% decrease in renal function from baseline by nuclear glomerular filtration rate, compared with a 25% decrease in those without TA-TMA (P=0.001). There was no TA-TMA-related mortality. Significant complications included end-stage renal disease (n=1) and polyserositis (n=3). Patients with TA-TMA were unable to complete cis-RA therapy after auto-SCT. We suggest that careful attention to blood pressure and urinalysis will assist in the early diagnosis of TA-TMA, whereas serum creatinine seems to be an insensitive marker for this condition.

Reduced-intensity conditioning is effective and safe for transplantation of patients with Shwachman-Diamond syndrome.

Allogeneic hematopoietic stem cell transplantation (HSCT) is the only potentially curative treatment for the BM dysfunction seen in patients with Shwachman-Diamond syndrome (SDS). Historically, these patients have fared poorly with intensive conditioning regimens with increased regimen-related toxicity especially involving the heart and lungs. We report our institutional experience with a reduced-intensity-conditioning protocol in seven patients with SDS and BM aplasia or myelodysplastic syndrome/AML. The preparative regimen consisted of Campath-1H, fludarabine and melphalan. Four patients received matched related marrow and three received unrelated stem cells (two PBSCs and one marrow). All but one was 8 of 8 allele HLA matched. All patients established 100% donor-derived hematopoiesis. No patient in this cohort developed grades III-IV GVHD. One patient had grade II skin GVHD that responded to systemic corticosteroids and one had grade I skin GVHD, treated with topical corticosteroids. Two out of seven patients developed bacterial infections in the early post transplant period. Viral infections were seen in four out of seven patients and were successfully treated with appropriate antiviral therapy. All patients are currently alive. These data indicate that HSCT with reduced-intensity conditioning is feasible in patients with SDS and associated with excellent donor cell engraftment and modest morbidity.

Allogeneic hematopoietic cell transplantation (HCT) in Hurler's syndrome using a reduced intensity preparative regimen.

Allogeneic hematopoietic cell transplantation (HCT) in patients with Hurler's syndrome can improve survival and ameliorate many aspects of Hurler's syndrome including neurologic decline and cardiac compromise. Unfortunately, the toxicity of traditional preparative regimens to organs affected by the syndrome may have deleterious effects. Additionally, despite the intensity of these regimens, achieving stable donor chimerism can be difficult. We report transplant outcomes following a reduced intensity, highly immunosuppressive preparative regimen consisting of alemtuzumab, fludarabine and melphalan prior to HCT in seven patients with Hurler's syndrome treated at two centers. Six patients received grafts from unrelated donors and one received a sibling donor graft. The preparative regimen was well tolerated. All patients had initial donor engraftment at 100 days; one patient had delayed loss of donor chimerism. There was no severe acute GVHD (no GI GVHD of grade II or more, no grade IV skin GVHD). Six of the seven children are surviving at a median of 1014 (726-2222) days post transplant. This reduced intensity preparative regimen has the potential to support engraftment and improve survival and outcome in patients with Hurler's syndrome undergoing HCT.