Early complications following haematopoietic SCT in children

Risk factors for hemorrhagic cystitis in children undergoing hematopoietic stem cell transplantation: a systematic review and meta-analysis

BACKGROUND

The risk factors for hemorrhagic cystitis (HC) in children undergoing hematopoietic stem cell transplantation (HSCT) are unclear. Therefore, we conducted this systematic review and meta-analysis to investigate the risk factors for HC in children undergoing HSCT.

METHODS

We performed this meta-analysis by retrieving studies from PubMed, EMBASE, and the Cochrane Library up to October 10, 2023, and analyzing those that met the inclusion criteria. I2 statistics were used to evaluate heterogeneity.

RESULTS

Twelve studies, including 2,764 patients, were analyzed. Male sex (odds ratio [OR] = 1.52; 95% confidence interval [CI], 1.16-2.00; p = 0.003, I2 = 0%), allogeneic donor (OR = 5.28; 95% CI, 2.60-10.74; p < 0.00001, I2 = 0%), human leukocyte antigen (HLA) mismatched donor (OR = 1.86; 95% CI, 1.00-3.44; p = 0.05, I2 = 31%), unrelated donor (OR = 1.58; 95% CI, 1.10-2.28; p = 0.01, I2 = 1%), myeloablative conditioning (MAC) (OR = 3.17; 95% CI, 1.26-7.97; p = 0.01, I2 = 0%), busulfan (OR = 2.18; 95% CI, 1.33-3.58; p = 0.002, I2 = 0%) or anti-thymoglobulin (OR = 1.65; 95% CI, 1.07-2.54; p = 0.02, I2 = 16%) use, and cytomegalovirus (CMV) reactivation (OR = 2.64; 95% CI, 1.44-4.82; p = 0.002, I2 = 0%) were risk factors for HC in children undergoing HSCT.

CONCLUSIONS

Male sex, allogeneic donor, HLA-mismatched, unrelated donor, MAC, use of busulfan or anti-thymoglobulin, and CMV reactivation are risk factors for HC in children undergoing HSCT.

The Impact of 131I-Metaiodobenzylguanidine as a Conditioning Regimen of Tandem High-Dose Chemotherapy and Autologous Stem Cell Transplantation for High-Risk Neuroblastoma

BACKGROUND

The optimal conditioning regimen of tandem high-dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT) for high-risk neuroblastoma (HR-NBL) has not been established. The efficacy of 131I-MIBG therapy is under exploration in newly diagnosed HR-NBL patients. Here, we compared the outcomes of tandem HDC/ASCT between the 131I-MIBG combination and non-MIBG groups.

METHODS

We retrospectively analyzed the clinical data of 33 HR-NBL patients who underwent tandem HDC/ASCT between 2007 and 2021 at the Seoul National University Children's Hospital.

RESULTS

The median age at diagnosis was 3.6 years. 131I-MIBG was administered to 13 (39.4%) of the patients. Thirty patients (90.9%) received maintenance therapy after tandem HDC/ASCT, twenty-two were treated with isotretinoin ± interleukin-2, and eight received salvage chemotherapy. The five-year overall survival (OS) and event-free survival (EFS) rates of all patients were 80.4% and 69.4%, respectively. Comparing the 131I-MIBG combined group and other groups, the five-year OS rates were 82.1% and 79.7% (p = 0.655), and the five-year EFS rates were 69.2% and 69.6% (p = 0.922), respectively. Among the adverse effects of grade 3 or 4, the incidence of liver enzyme elevation was significantly higher in the non-131I-MIBG group.

CONCLUSIONS

Although tandem HDC/ASCT showed promising outcomes, the 131I-MIBG combination did not improve survival rates.

Incidence of acute kidney injury after hematopoietic stem cell transplantation in children: a systematic review and meta-analysis

While acute kidney injury (AKI) has been reported after hematopoietic stem cell transplantation (HCT) in children, the incidence of this condition in the pediatric population has not been fully addressed. To assess the incidence of pediatric AKI after HCT treatment,we conducted a systematic literature review. Databases PubMed, Embase, Cochrane Library, and WOS were searched as of June 2022 to identify studies on the incidence and the risk of death in AKI children undergoing HCT. Random effects and generic inverse variance methods were used, and effect estimates were subsequently derived from individual studies. Twelve cohort studies with 2 159 HCT cases were included in this analysis. The combined estimated incidence of AKI and severe AKI (stage AKI III) was 51% (95% confidence interval (CI) 39-64%) and 12% (95%CI 4-24%), respectively. The estimated incidence of AKI based on RIFLE (pRIFLE), AKIN, and KDIGO criteria was 61% (95%CI 40-82% score I 95.1%), 64% (95%CI 49-79% score I 90.4%), and 51% (95%CI 2-100% score 99.0%), respectively. However, we found no significant correlation between the years of publication of the included studies and the incidence of AKI.  Conclusions: AKI affects approximately half of the children after HCT. With the advancements in medical techniques, it is expected that AKI in this population will decrease gradually. What is Known: • Hematopoietic stem cell transplantation is recognized as a treatment for malignant and non-malignant diseases in children. • Hematopoietic stem cell transplantation causes acute kidney injury in children. What is New: • This metanalysis showed that the overall frequency of post-HCT AKI in children is 51%. • The frequency of severe AKI after HCT was found to be 12%.

Short- and long-term outcome of allogeneic stem cell transplantation in infants: A single-center experience over 20 years

INTRODUCTION

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a treatment method for a wide range of malignant and non-malignant diseases. Infants constitute a distinct patient group, especially due to their organ immaturity and differences in drug metabolism. The present paper aims to analyse the short- and long-term outcomes after allo-HSCT in infants.

MATERIAL AND METHODS

In the study period, 67 patients under 12 months of age underwent allo-HSCT. This study is a retrospective analysis of patient medical records, in the form of paper and electronic documentation.

RESULTS

The probability of 5-year OS was 69% and 72% in patients with malignant and non-malignant diseases, respectively. The allo-HSCT from a matched donor was associated with improved OS in comparison to haploidentical donor (0.8 vs. 0.58%, p = 0.0425). The overall incidence of acute graft-vs.-host disease (aGVHD) was 59.3%, and grade III-IV aGVHD was diagnosed in 23% of patients. The 100-day non-relapse mortality (NRM) in the study cohort was 17.9%, while the 5-year NRM was 26.9%. Among the causes of NRM, infections occurred in 83.3% of patients, and aGVHD in 16.3% of individuals. Twenty-two children (32.8%) required hospitalization in the pediatric intensive care unit (PICU). The median length of PICU hospitalization was 6 days (range 1 to 12 days). Late sequelae diagnosed during post-transplant surveillance included ocular disorders in 26.8% of patients, cardiac complications in 4.4%, as well as endocrinopathy with short stature (<3rd percentile) in 37.2% and overt hypothyroidism in 35.4%. In the long-term perspective, 83.3% of survivors were able to attend a regular school.

CONCLUSIONS

Improvements in unrelated donor availability, and better supportive care resulted in better outcomes. Management of infant allo-HSCT recipients requires the formation of multi-disciplinary specialist teams. In addition, the role of parental empowerment must be acknowledged; for example, in speech therapy and rehabilitation.

Low incidence of hemorrhagic cystitis following ex vivo T-cell depleted haploidentical hematopoietic cell transplantation in children

Hemorrhagic cystitis (HC) is a debilitating complication following allogenic hematopoietic cell transplantation (HCT). HLA disparity and T-cell depletion have been implicated as risk factors for HC. However, reports on the incidence and risk factors for HC in ex vivo T-cell depleted haploidentical HCT (haploHCT) in children are lacking. We studied 96 haploHCT procedures performed in 83 children between 2002 and 2017. Sixty-three patients were diagnosed with a malignant disease and 20 with nonmalignant disease. All but three patients with SCID underwent myelotoxic and/or lymphotoxic conditioning therapy. Grafts were CD3+ (36.5%) or TcRαβ+ (63.5%) depleted to prevent graft versus host disease (GvHD). Fourteen patients (14.6%) were diagnosed with HC; 12 (12.5%) had clinically significant stage II-IV HC. All patients with HC had BK viruria and/or viremia. Increasing age and chemotherapeutic treatment prior to conditioning were identified as risk factors for HC. Immune recovery did not significantly differ between patients with and without HC. Thus, we report a low incidence of HC in pediatric haploHCT using ex vivo T-cell depletion. The combination of a reduced toxicity conditioning regimen, and typically absent pharmaceutical post-HCT GvHD prophylaxis in our patients might have contributed to the decreased the risk of HC, despite HLA disparity.

Review of a three-year study on the dental care of onco-hematological pediatric patients

The aim of this study was to provide an updated review of dental procedures undertaken at the dental unit of the Onco-hematology service of the Instituto da Criança at the Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (ICr/HC-FMUSP). We retrospectively reviewed 565 of 1902 medical and dental records of patients diagnosed with onco-hematological diseases who were seen in a 3-year study (January 2015 to December 2017). We assessed data regarding population characteristics, onco-hematological diagnosis and dental procedures performed. Of the selected medical records, preventive dentistry was the most common procedure undertaken in this population, followed by oral maxillofacial surgeries, restorative dentistry and oral mucositis treatment. The most prevalent malignant diagnosis was acute lymphocytic leukemia, and the most prevalent nonmalignant diagnosis was sickle-cell anemia. Preventive dental procedures represent most of the dental procedures undertaken in hospitalized onco-hematological pediatric patients.

Higher Peak Tacrolimus Concentrations after Allogeneic Hematopoietic Stem Cell Transplantation Increase the Risk of Endothelial Cell Damage Complications

Noninfectious transplantation-related complications (TRCs) such as graft-versus-host disease (GVHD) and endothelial cell damage (TRC-EC) are critical after allogeneic hematopoietic stem cell transplantation. Tacrolimus (TAC) is used to control GVHD. Hypertension and renal failure are common adverse events after TAC treatment. Higher blood concentrations of TAC would be expected to reduce the risk of GVHD but may increase TRC-EC. TRC-EC often develops in patients with GVHD; thus, it is difficult to clinically determine the proper intensity of immunosuppression. We therefore evaluated the impact of weekly mean/peak TAC blood concentrations (PTCs) on TRC-EC occurrence and prognosis. Patients (N = 295) who received TAC as a GVHD prophylaxis at our institute from 2009 to 2016 were eligible for this retrospective study. Forty-three patients were diagnosed with TRC-EC: 8 with sinusoidal obstructive syndrome, 28 with transplant-associated microangiopathy, and 7 with idiopathic pneumonia syndrome. The cumulative incidence of TRC-EC at 12 months was 13.8% (95% confidence interval [CI] 10.1% to 18.1%). After multivariate analysis high PTCs during days 22 to 28 (hazard ratio [HR] 2.47; 95% CI, 1.37 to 4.45; P < .01) and grades II to IV acute GVHD (HR, 5.61; 95% CI, 2.99 to 10.53; P < .01) were associated with TRC-EC occurrence. The probability of overall survival (OS) at 12 months was 67.7% (95% CI, 61.7% to 73.0%). After multivariate analysis TRC-EC diagnosis (HR, 2.47, 95% CI, 1.59 to 3.83; P < .01) and high-risk disease (HR, 1.75; 95% CI, 1.17 to 2.61; P < .01) were significantly associated with poor OS. In conclusion, higher PTC during days 22 to 28 increased the risk of TRC-EC. TRC-EC development was associated with poor OS.

Diagnostic Utility of Complement Immunohistochemical Studies in Post-Stem Cell Transplant Intestinal Thrombotic Microangiopathy: Case Report

Thrombotic complications are a significant source of morbidity and mortality following hematopoietic stem cell transplants. Among them, transplant-associated thrombotic microangiopathy (TA-TMA) is a well-recognized syndrome that can affect various organ systems. Its etiology is related to endothelial injury accompanied by complement activation. As many of the signs and symptoms of the disease are also encountered in other complications following hematopoietic stem cell transplant, it can often be difficult to establish the diagnosis based on clinical data alone. Histopathologic examination of various tissues may be performed in difficult cases. However, the microscopic features of TA-TMA also overlap with those seen in other posttransplant complications, suggesting a need for additional tests to help in diagnosis. Here we describe a patient who presented with hemolytic anemia, thrombocytopenia, renal and neurological impairment, who also developed significant bloody diarrhea. Flexible sigmoidoscopy with biopsies was performed to determine the exact etiology of his gastrointestinal bleed. A diagnosis of intestinal TA-TMA was established with the use of immunohistochemical stains for complement components C5b-9 and C4d. This is the first report that highlights the utility of complement staining on histologic sections from digestive samples to render a definitive diagnosis of intestinal TA-TMA.

Association between C-reactive protein levels in the first 1-3 days post-transplant and allogeneic immune reactions

AIM

The purpose of this study was to determine whether C-reactive protein (CRP) in the first 1-3 days post-transplant could predict allogeneic immune reactions, including engraftment syndrome or acute graft-versus-host disease (GVHD), in pediatric haploidentical stem cell transplantation.

PATIENTS & METHODS

The study population comprised 175 consecutive pediatric patients. Receiver operating characteristic analysis was performed to identify the cut-off CRP value.

RESULTS

The high-CRP group (≥20.1 mg/l) was associated with an increased occurrence of engraftment syndrome (hazard ratio [HR] = 2.046; p = 0.008), II-IV acute GVHD (HR = 2.203; p = 0.001) and severe GVHD (HR = 6.371; p = 0.004).

CONCLUSION

Our data suggest that higher CRP during the first 1-3 days post-transplant could be a predictor of allogeneic immune reactions.

Safety of peritoneal and pleural drain placement in pediatric stem cell transplant recipients with severe veno-occlusive disease

Hepatic VOD (veno-occlusive disease) is a serious complication of HSCT (hematopoietic stem cell transplantation) and has historically been associated with high mortality. This obstruction to hepatic flow often results in fluid collections in the peritoneal and pleural cavities. Catheter placement to drain ascites or pleural fluid may reduce intra-abdominal hypertension and/or improve respiratory parameters. The safety of these interventions among critically ill, immunocompromised children is unknown. Among 32 HSCT recipients (2000-2012) with severe VOD, we assessed the primary outcome of procedural complication from peritoneal drain placement. Twenty-four (75%) patients underwent peritoneal drain placement. No patient sustained visceral perforation or hemorrhage with drain placement. Overall mortality was 47% (n = 15). The procedure was not associated with increased overall mortality (p > 0.99). Eight (25%) peritoneal drains required replacement for malfunction. Of 24 patients with peritoneal drains, one (4%) patient had a positive culture from ascitic fluid. Eight (25%) patients underwent pleural drain placement. No pleural drain-related procedural complication or infection occurred. Four (50%) of the eight patients with pleural drains had de-escalation in oxygen requirement at drain removal, compared to time of placement. In this study, peritoneal and pleural drains were safe interventions for children with severe VOD.

BK Virus-Associated Hemorrhagic Cystitis After Allogeneic Hematopoietic Stem Cell Transplantation in the Pediatric Population

OBJECTIVE

To study the incidence, risk factors, and treatment of hemorrhagic cystitis secondary to BK-virus reactivation (HC-BKV) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in the pediatric population.

METHODS

Case-control study in which all pediatric patients (0-18 years) who underwent allo-HSCT from September 2009 to January 2014 were followed.

RESULTS

Twenty-nine patients underwent an allo-HSCT. The median age was 9 years (range = 6 months to 15 years), 61% male. The primary diagnosis was acute lymphoblastic leukemia (72.4%). Six (20.7%) developed HC-BKV. In a multivariate analysis of risk factors, it was observed that the reactivation of BK virus was associated with age more than 10 years ( P = .098) and those with positive serology for Epstein-Barr virus ( P = .06). Five of the 6 patients with HC-BKV received cidofovir (CDV) at doses of 3 to 5 mg/kg/week. The treatment lasted a median of 3 cycles (range = 2-5). One of the patients (20%) developed nephrotoxicity. Of the 5 patients treated with CDV, 3 (60%) had a complete response, 1 (20%) partial response, and 1 (20%) no response.

CONCLUSION

We conclude that HC-BKV is a frequent complication after allo-HSCT. CDV therapy can be effective but controlled clinical trials are needed.

Characteristics of Children With Cancer Discharged or Admitted From the Emergency Department

BACKGROUND

Emergency department (ED) utilization by children with cancer is poorly understood. Among children with cancer, we explored reasons for ED visits and factors associated with admission within U.S. children's hospitals.

METHODS

A retrospective study of the 2011-2013 Pediatric Health Information System (PHIS) was conducted. Eligible ED visits included those within 365 days from the first inpatient encounter with an International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) code for cancer. Patient characteristics and reasons for ED visits were assessed. Factors associated with admission from the ED were examined with multivariable regression.

RESULTS

There were 26,770 ED visits by 17,943 children with cancer at 39 children's hospitals during the study period. Half of children with cancer visited the ED within 1 year after their first cancer hospitalization in PHIS. Fifty-six percent of ED visits resulted in admission. Fever or neutropenia accounted for the largest proportion of reasons for visits (34.6%). Risk factors for admission were as follows: "Other" race/ethnicity as compared to white, non-Hispanic (odds ratio [OR] = 1.4, 95% confidence interval [CI] 1.2-1.6), history of transplant (OR = 1.7, 95% CI 1.4-2.1), and ED visits reasons including neutropenia (OR = 43.4, 95% CI 36.0-52.3), blood stream infection (OR = 3.3, 95% CI 2.8-3.9), pancytopenia (OR = 28.8, 95% CI 18.1-45.9), dehydration (OR = 2.3, 95% CI 1.9-2.9), or pneumonia (OR = 3.8, 95% CI 2.8-5.1).

CONCLUSIONS

Children with cancer have high ED usage within 1 year after their first cancer hospitalization. Age, demographic factors, and reasons for ED visits significantly impacted admission from the ED. Further research should focus on ED utilization among children with cancer.

Imaging of acute and subacute toxicities of cancer therapy in children

Effective cancer therapies have resulted in significant improvement in survival. However, treatment-related acute and subacute complications are a cause of significant morbidity and mortality. Effects of cancer therapy in children can be seen early in the survival period or later in life in almost all organ systems of the body. Many of these conditions are evaluated by imaging and some are diagnosed based on characteristic imaging features. This article aims to discuss acute and subacute toxicities of cancer therapy in children involving multiple organ systems, pulmonary, gastrointestinal, hepatobiliary, genitourinary and musculoskeletal systems with emphasis on those in which imaging plays a role in diagnosis or management. We also discuss the role of imaging and choice of imaging modalities in these conditions.

Unrelated hematopoietic stem cell transplantation in the pediatric population: single institution experience

OBJECTIVE

Hematopoietic stem cell transplantation has been successfully used to treat the pediatric population with malignant and non-malignant hematological diseases. This paper reports the results up to 180 days after the procedure of all unrelated hematopoietic stem cell transplantations in pediatric patients that were performed in one institution.

METHODS

A retrospective review was performed of all under 18-year-old patients who received unrelated transplantations between 1995 and 2009. Data were analyzed using the log-rank test, Cox stepwise model, Kaplan-Meier method, Fine and Gray model and Fisher's exact test.

RESULTS

This study included 118 patients (46.8%) who received bone marrow and 134 (53.2%) who received umbilical cord blood transplants. Engraftment occurred in 89.47% of the patients that received bone marrow and 65.83% of those that received umbilical cord blood (p-value<0.001). Both neutrophil and platelet engraftments were faster in the bone marrow group. Acute graft-versus-host disease occurred in 48.6% of the patients without statistically significant differences between the two groups (p-value=0.653). Chronic graft-versus-host disease occurred in 9.2% of the patients with a higher incidence in the bone marrow group (p-value=0.007). Relapse occurred in 24% of the 96 patients with malignant disease with 2-year cumulative incidences of 45% in the bone marrow group and 25% in the umbilical cord blood group (p-value=0.117). Five-year overall survival was 47%, with an average survival time of 1207 days, and no significant differences between the groups (p-value=0.4666).

CONCLUSION

Despite delayed engraftment in the umbilical cord blood group, graft-versus-host disease, relapse and survival were similar in both groups.

Pain Management for Children during Bone Marrow and Stem Cell Transplantation

Pain management for children during bone marrow and stem cell transplantation is a significant clinical challenge for the health care team. Pain management strategies vary by institution. This paper reports on the use of a pediatric pain management service and patient- and caregiver-controlled analgesia for children undergoing transplant. This 2-year retrospective chart review examined the pain management practices and outcomes of children undergoing bone marrow and stem cell transplants in a large urban teaching hospital during 2008 and 2009. We concluded that patient- and caregiver-controlled analgesia is a well-tolerated modality for pain control during hospitalization for transplantation at this institution.

Transient renal enlargement in pediatric hematopoietic cell transplant recipients

Age-dependent renal length tables are routinely used when interpreting pediatric ultrasound. Standard renal length tables may not be accurate for HCT patients due to treatment effects on kidney size. The purpose of this study was to determine whether renal size changes from expected lengths based on age after HCT in the absence of other markers of renal disease. Four hundred and fifty renal measurements were made on 101 patients who underwent HCT between 2006 and 2010. Renal length was measured at 1-90 days pre-HCT and at 0-30, 31-90, 91-180, and 181+ days post-HCT. Values were compared with normal renal length tables. Average post-HCT renal lengths were greater than established normative renal length data within every age group. Age-adjusted average renal lengths measured at 0-30 and 31-90 days post-transplantation were significantly larger than pre-HCT renal lengths, with relative increases of 6.9% (4.5, 9.4; p < 0.001) and 3.9% (1.4, 6.4; p = 0.003), respectively. Average renal length did not differ significantly after 90 days post-transplantation. HCT patients may have larger kidneys in the absence of renal disease. Awareness of the potential phenomenon of transient renal enlargement following HCT can prevent misdiagnosis and eliminate unnecessary diagnostic evaluations, interventions, anxiety, resource allocation, and financial costs.

BK viremia precedes hemorrhagic cystitis in children undergoing allogeneic hematopoietic stem cell transplantation

BK virus is associated with hemorrhagic cystitis after hematopoietic stem cell transplantation (HSCT), although evidence supporting a causal relationship remains limited. Although BK viruria is common after HSCT, BK viremia may better predict clinically significant cystitis, similar to its predictive value for nephropathy after kidney transplantation. We hypothesized that BK viremia would precede hemorrhagic cystitis in a cohort of 88 consecutive children prospectively enrolled to originally study thrombotic microangiopathy in the first 100 days after allogeneic HSCT. Cox regression models with time-varying covariates assessed the association between different BK viremia cutoffs and the development of hemorrhagic cystitis, defined as at least macroscopic hematuria. Subjects with a peak plasma BK viral load 1 to 9999 copies/mL had an adjusted hazard ratio of 4.2 (95% confidence interval (CI), 1.3 to 13.7) for the development of hemorrhagic cystitis. Those with peak BK viremia >100,000 copies/mL had an adjusted hazard ratio of 116.8 (95% CI, 12 to 1136) for cystitis. Other independent risk factors for hemorrhagic cystitis included age >7 years and HHV-6 viremia. Neither graft-versus-host disease nor achieving engraftment increased the risk for cystitis. If therapeutic strategies are found to be effective, these observations may support screening for BK viremia after HSCT, as currently recommended for other DNA viruses.

Experiences of t-PA use in moderate-to-severe hepatic veno-occlusive disease after hematopoietic SCT: is it still reasonable to use t-PA?

Hepatic veno-occlusive disease (VOD) remains one of the most severe complications of hematopoietic SCT (HSCT). Anticoagulation and thrombolytic therapies using tissue-plasminogen activator (t-PA) have been used, but are reported to be ineffective and are associated with significant bleeding complications. We analyzed 56 moderate-to-severe post HSCT hepatic VOD cases treated with t-PA. We analyzed clinical outcomes according to the maximal daily dose of t-PA (t-PAmax) and the severity of VOD. Patients were stratified by t-PAmax10 mg (n=37) vs t-PAmax>10 mg (n=19). A higher t-PAmax was associated with increased mortality. Bleeding complications were more likely at higher t-PAmax in both moderate and severe VOD (P=0.036, 0.063), especially if patients had concomitant use of anticoagulants (36.4% vs 13.3%). In moderate VOD, the response rate was 86.4% for t-PAmax10 mg/day and 80% for t-PAmax>10 mg compared with 33.3% and 7.1%, respectively, for severe VOD (P=0.106). The 5-year OS in moderate and severe VOD was 49% and 7%, respectively, and it was 32% for t-PAmax10 mg and 18% for t-PAmax>10 mg. Our data demonstrate that lower bleeding complications and bleeding-related deaths may result from strict limitations on the t-PAmax without concomitant use of anticoagulation therapy. However, the overall response and survival outcomes should be re-evaluated by a well-validated study in the future.

Hemorrhagic cystitis in a cohort of pediatric transplantations: incidence, treatment, outcome, and risk factors

Hemorrhagic cystitis (HC) can be a severe complication in hematopoietic stem cell transplantation (HSCT). To identify risk factors and etiology and to improve treatment, a number of factors were analyzed retrospectively in a cohort of 74 consecutive pediatric HSCTs between 2007 and 2009 in a single institution. The 74 transplantations were done in 67 children. Potential risk factors for HC were age, gender, underlying disease, ablative conditioning, graft-versus-host disease prophylaxis, unrelated donor, stem cell source, conditioning regime, acute graft-versus-host disease and cytomegalovirus reactivation. Fourteen patients developed HC (19%). In all but 4 cases (71%), HC appeared after engraftment. Severity was assessed as grade 1 in 1, grade 2 in 8, and grade 3 in 5 cases. In 79% of the patients with HC, urine samples showed BK virus. This may provide guidance for future prevention policies. In 11 children, treatment included forced hydration, spasmolytics, and bladder irrigation. Three children required cystoscopy, intravesical therapy and/or antiviral therapy. Statistical analysis revealed age over six years to be a risk factor for the development of HC. We conclude that current conditioning regimens lead to a still considerable incidence of HC in pediatric HSCT, necessitating the evaluation of screening protocols and preventive measures.

Thrombosis in stem cell transplantation

Hemostatic changes and thrombotic events are frequent in patients undergoing stem cell transplantation. Arterial and venous thromboses are major causes of morbidity and mortality. Thrombotic complications can be classified into four groups including: catheter-related thrombosis, venous thromboembolic (VTE) events, sinusoidal obstructive syndrome (SOS)/veno-occlusive disease, and transplant-associated thrombotic microangiopathy (TAM). The incidence of catheter-related thrombosis is 8-20% in patients undergoing autologous hematopoietic stem cell transplantation (HSCT), and the incidence is low in syngeneic and allogeneic transplant patients. Venous duplex Doppler ultrasound, venogram, and computed tomography scan are required to visualize the venous thrombus. The treatment should be aimed at the prevention of pulmonary embolism, the avoidance of thrombus extension, and the preservation of catheter patency. Patients undergoing HSCT may have risk factors for VTE including underlying malignancy, traumatic brain injury, prolonged hospitalization, administration of conditioning regimens, and central venous catheters. Important risk factors are presence of history of VTE and graft-versus-host disease. One-year incidence of symptomatic VTE is 3.7%. SOS, also known as veno-occlusive disease, is a serious liver disease, seen in approximately 50-60% of HSCT patients. The mortality rate from the severe form of SOS is 84.3% and majority of the patients have multi-organ failure. The frequency is quite low after autologous transplantation. Risk factors for SOS include pre-existing hepatic damage, previous high-dose chemotherapy and abdominal irradiation, female gender and donor-recipient human leukocyte antigen disparity. Cyclophosphamide and busulphan are the most common agents with the highest incidence and fatal SOS. Histopathologic features of SOS include dilatation of sinusoids, necrosis of perivenular hepatocytes, and obstruction of small intrahepatic central venules by microthrombi and fibrin deposition. Signs of SOS usually occur within first 30 days after HSCT including hyperbilirubinemia, hepatomegaly, ascites, and weight gain. Symptoms of liver failure, including encephalopathy, coagulopathy, and renal failure will appear in severe form. A hepatic venous pressure gradient above 10 mmHg is highly specific for SOS. Early use of defibrotide has been shown to be effective in the treatment of high-risk SOS. TAM is a distinct, infrequent, and significant life-threatening complication of HSCT. TAM is seen in the range of 0·5-76% and was reported to be 10-25% in patients undergoing allogeneic HSCT with a mortality rate around 50%. It can also be seen after autologous HSCT and mainly affects the glomerular capillaries. There has been no standard therapy for TAM. Few case series reported good response to rituximab and high-dose corticosteroids were used with limited success. Trials with complement inhibitors such as eculizumab are currently underway.

Third-party mesenchymal stromal cell infusion is associated with a decrease in thrombotic microangiopathy symptoms observed post-hematopoietic stem cell transplantation

TA-TMA is a pathology that occurs after allogenic HSC transplantation with an incidence of 4-13%, and represents one of the most severe vascular damage related with this therapy. We report here the case of a nine-yr-old girl suffering from a severe refractory aplastic anemia who received an unrelated, 9/10 HLA-matched HSC. Soon after transplantation, the patient developed a graft-versus-host disease (GvHD), a TA-TMA, and renal insufficiency. These pathologies remained refractory to the various treatments undertaken and required several hospitalizations in the intensive care unit. On day 106 post-HSC transfusion, after several episodes of intensive care, the patient was infused with mismatched, third-party MSCs. Schizocyte levels rapidly decreased after MSC infusion, and two wk later, most biological parameters returned to normal. Erythrocyte and thrombocyte transfusions were discontinued, and the patient remained stable for 10 wk. Thereafter, TA-TMA symptoms, viral reactivation, pleural and cardiac effusions reappeared and lead to the death of the patient. Our observations suggest that allogenic MSC infusion may decrease the symptoms of TA-TMA, but further investigation is required to determine how and when MSC should be infused to develop a long-lasting protective effect.

Introduction of sodium pentosan polysulfate and avoidance of urethral catheterisation: improved outcomes in children with haemorrhagic cystitis post stem cell transplant/chemotherapy

PURPOSE

Haemorrhagic cystitis (HC) is an uncommon but potentially devastating complication of chemotherapy and bone marrow transplantation in children. We aimed to test the hypothesis that early recognition, sodium pentosan polysulfate (SPP), and avoidance of urethral catheterisation improve outcomes in children with HC.

METHODS

A retrospective case note review was performed of all patients treated for HC in our hospital from 2002 to 2010. A protocol for the management of HC was introduced in 2007 advocating early detection, use of SPP, and avoidance of urethral catheterisation. Data collected on each patient included primary condition, medications at onset, blood transfusions, duration of symptoms, catheter usage, and outcome. Statistical analysis was performed using the Mann-Whitney U test, and Fisher's Exact test as appropriate, P < .05 being significant.

RESULTS

Five patients were treated using protocol with 5 historical controls. There was no significant difference between the ages of the group, diagnosis, and treatment at onset of HC. In the historical group, 4 of 5 died with HC, but all recovered in the protocol group (P < .05). Blood transfusion requirements were also significantly reduced after protocol introduction (P < .05).

CONCLUSION

Early identification, avoidance of urethral catheterisation, and use of SPP significantly reduces blood transfusion requirements and mortality from HC.

Acute renal endothelial injury during marrow recovery in a cohort of combined kidney and bone marrow allografts

An idiopathic capillary leak syndrome ('engraftment syndrome') often occurs in recipients of hematopoietic cells, manifested clinically by transient azotemia and sometimes fever and fluid retention. Here, we report the renal pathology in 10 recipients of combined bone marrow and kidney allografts. Nine developed graft dysfunction on day 10-16 and renal biopsies showed marked acute tubular injury, with interstitial edema, hemorrhage and capillary congestion, with little or no interstitial infiltrate (≤10%) and marked glomerular and peritubular capillary (PTC) endothelial injury and loss by electron microscopy. Two had transient arterial endothelial inflammation; and 2 had C4d deposition. The cells in capillaries were primarily CD68(+) MPO(+) mononuclear cells and CD3(+) CD8(+) T cells, the latter with a high proliferative index (Ki67(+) ). B cells (CD20(+) ) and CD4(+) T cells were not detectable, and NK cells were rare. XY FISH showed that CD45(+) cells in PTCs were of recipient origin. Optimal treatment remains to be defined; two recovered without additional therapy, six were treated with anti-rejection regimens. Except for one patient, who later developed thrombotic microangiopathy and one with acute humoral rejection, all fully recovered within 2-4 weeks. Graft endothelium is the primary target of this process, attributable to as yet obscure mechanisms, arising during leukocyte recovery.

Vascular endothelium changes after conditioning in hematopoietic stem cell transplantation: role of cyclophosphamide and busulfan

Vascular endothelial injury, a feature of some complications of hematopoietic stem cell transplantation (HSCT), is characterized by increased endothelial cells. We investigated that classical pretreatment drugs in HSCT could result in vascular endothelial injury in mice. Six-to eight-week-old female BALB/c mice were divided into a control group, a cyclophosphamide group (60 mg/kg per day for 2 days) and a busulfan group (4 mg/kg per day for 4 days). We observed the general state of health and regularly counted the number of white blood cells. Circulating endothelial cells and their progenitors were estimated by flow cytometry. Morphologic endothelial changes were analyzed with optical and transmission electron microscopy. After conditioning with cyclophosphamide or busulfan, white blood cells fell to a low number with injuries noted on hematoxylin and eosin-stained pathology sections. Circulating endothelial cells and their progenitors peaked significantly higher than in the control group. Vascular endothelial injuries were observed in the 2 experimental groups by transmission electron microscopy. These data support the hypothesis the vascular endothelial injury occurs during conditioning with cyclophosphamide or busulfan for HSCT, with simultaneous mobilization of endothelial progenitor cells.

Hyperbaric oxygen therapy in a patient with autosomal dominant polycystic kidney disease with a perinephritic abscess

A 68-year-old female in hemodialysis due to autosomal dominant polycystic kidney disease underwent resection of cysts in her right kidney via a laparoscopic approach due to abdominal pain. Three weeks after surgery, she was admitted with sepsis. A CT scan showed a large abscess around the right kidney. Percutaneous drainage of abscess was performed. The pus smear showed Gram-positive cocci and the culture contained methicillin-resistant Staphylococcus aureus. Ciprofloxacin, clindamycin and vancomycin were given. In the 3 weeks following admission, she remained febrile and septic and showed a progressive deterioration in her general condition, along with malnutrition and persistent drainage of purulent material from her right flank. The antibiotic therapy was changed to vancomycin, metronidazole and meropenem, but no improvement was observed. Because of the high risk associated with carrying out an open nephrectomy, we decided to use hyperbaric oxygen therapy (HBOT) as a potentially useful measure to control her infection. The patient underwent 26 daily sessions of 100% hyperbaric oxygen (2.5 atm). The use of HBOT induced a notable break in the clinical course of this patient's retroperitoneal infection. She was discharged after day 58 without any signs of inflammatory activity, and she has not presented reactivation of infection since then. We think that this case suggests that this therapy could be a new therapeutic tool in the management of patients with similar clinical features when all other therapeutic measures have failed. We did not find any other reports of the use of HBOT in infections of renal cysts.

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.

BK virus-associated hemorrhagic cystitis presenting as mural nodules in the urinary bladder after hematopoietic stem cell transplantation

We report an unusual sonographic presentation of late-onset hemorrhagic cystitis caused by BK virus infection in an 8-year-old who had undergone hematopoietic stem cell transplantation for treatment of relapsed acute lymphoblastic leukemia. Sonography showed the presence of multiple bladder nodules in a background of diffuse bladder wall thickening. The dominant bladder nodule showed increase in size on serial sonograms and was vascularized on Doppler interrogation. Biopsy confirmed BK virus-associated cystitis. Recognition of this sonographic appearance in the appropriate clinical setting might obviate the need for biopsy in these children.

Hepato-biliary late effects in survivors of childhood and adolescent cancer: a report from the Children's Oncology Group

Curative therapy for childhood and adolescent cancer translates to 1 in 640 young adults being a survivor of cancer. Although acute hepato-biliary toxicity occurs commonly during pediatric cancer therapy, the impact of antineoplastic therapy on long-term liver health in childhood/adolescent cancer survivors is unknown. This article reviews the medical literature on late liver dysfunction following treatment for childhood/adolescent cancer. We also outline the Children's Oncology Group (COG) guidelines for screening and follow-up of hepato-biliary sequelae. As the population of survivors grow and age, vigilance for risks to hepatic health needs to continue based on specific exposures during curative cancer therapy.

Prospective evaluation of acute and chronic renal function in children following matched related donor hematopoietic stem cell transplantation

Acute and chronic renal impairment are important complications after HSCT. A prospective study was conducted to investigate the glomerular renal function in children who received allogeneic HSCT from matched related donors. Non-radiation conditioning regimens were used in all but one patient. CrCl and serial measurements of serum creatinine were evaluated prior to HSCT, within the first 100 days and one yr after. AKI was defined as at least a 1.5-fold rise in pre-HSCT serum creatinine within the first 100 days and classified as grade 1 to 3 according to the new definition criteria proposed by "AKI Network." Fifty-seven patients were enrolled in the study and 24 patients (42%) had AKI. CsA, amphotericin B, and SOS were found as risk factors for AKI. One yr after HSCT five patients (10%) had CKD and none of them required dialysis. None of the parameters were found as a predictor for CKD. We conclude that AKI is an important complication of HSCT. Careful monitoring of renal function, minimizing the use of nephrotoxic medication, prophylaxis, and effective treatment of SOS might be effective preventive measures to decrease the incidence of AKI.

A phase I/II study of the safety and efficacy of the addition of sirolimus to tacrolimus/methotrexate graft versus host disease prophylaxis after allogeneic haematopoietic cell transplantation in paediatric acute lymphoblastic leukaemia (ALL)

Sirolimus has been shown to have activity against human acute lymphoblastic leukaemia at serum levels used for immunosuppression. We hypothesized that the addition of sirolimus to a tacrolimus/methotrexate graft-versus-host disease (GVHD) prophylaxis regimen would decrease relapse after haematopoietic stem cell transplantation and initiated a phase I/II study to demonstrate safety, feasibility, and efficacy. The study cohort included 18 patients in high-risk (HR) first complete remission (CR1), 16 in HR CR2, 17 in intermediate risk (IR) CR2, and 12 in CR3+. The 2-year event-free survival (EFS) of the cohort was 66% (standard error 6.4). EFS of risk groups was 74%, 81%, 44% and 46% for CR1, IR CR2, HR CR2 and CR3+ patients respectively, and did not differ by stem cell source. Cumulative incidence of acute GVHD grade II-IV and III-IV was 38% and 21% respectively, while the cumulative incidence of chronic GVHD was 32%. Cumulative incidence of transplant-related mortality and relapse was 10% and 25% respectively. Significant toxicities included veno-occlusive disease [seven patients (11%)], transplant-associated microangiopathy (three patients), and idiopathic pneumonitis (one patient). In summary, sirolimus-based GVHD prophylaxis can be given safely in this population and early survival results are promising. A phase III trial to test whether sirolimus decreases relapse and improves outcome after transplantation for ALL is ongoing.