Major ABO incompatible BMT in children: determining what residual volume of donor red cells can safely be infused following red cell depletion

Major ABO incompatible BM transplantation carries a risk of acute haemolysis. Red cell depletion reduces this risk but not all incompatible RBC (iRBCs) are removed and in children the residual volume can be significant relative to body weight. We sought to determine the volume of iRBCs that can be safely given to children. All patients receiving fresh BM from a donor with a major ABO blood group mismatch between January 2000 and July 2013 at the Hospital for Sick Children, Toronto, were included. Seventy-eight patients were identified. The median volume of iRBCs transfused was 1.6 mL/kg (range 0.1-10.6 mL/kg). Thirty-five patients had minor haemolytic events and five patients had clinically significant adverse events. Two patients, who received 3.66 and 3.9 mL iRBCs/kg, developed renal impairment and in one case hypoxia and hyperbilirubinaemia. One patient had mild hypotension that resolved with i.v. fluid. Two patients developed hypotension secondary to sepsis and unrelated to BM infusion. Although signs of haemolysis occur, with appropriate hydration and monitoring of renal function, clinically significant adverse events related to the infusion of ABO incompatible BM are rare, and, in this study, were only seen in patients receiving >3 mL/kg of iRBCs per kg.

Acute gut GVHD in children: does skin involvement matter?

Gut GVHD (G-GVHD) is frequently the most severe and difficult to treat compared with skin GVHD. It is unknown if skin involvement with G-GVHD has prognostic significance. To compare the prognosis of acute isolated G-GVHD vs acute gut and skin GVHD (GS-GVHD) in children following allo-SCT. Allo-SCT recipients from Jan 2000-Dec 2009 were included and patients who underwent endoscopy and gut biopsy for G-GVHD were identified. Four hundred and fifty children (0-18 years) underwent allo-SCT during the study period. Seventy-nine (17.5%) patients underwent endoscopy and biopsy. At least stage II was required for skin involvement. Forty nine patients had G-GVHD and 30 had combined, GS-GVHD. The majority of patients received CsA and MTX for GVHD prophylaxis. Sixty-seven percent of patients with GS-GVHD had grade III-IV while only 31% had grade III-IV in the G-GVHD group. Median follow-up was 6.3 years (range 3.6-11.9 years). Relapse rate was similar in both the groups. However, children with G-GVHD had a significantly higher risk of dying from GVHD related complications (37% vs 16%) resulting in superior survival for those with skin involvement (79% vs 49% P=0.02). Extension of G-GVHD to the skin may suggest a better outcome.

High alpha-1 antitrypsin clearance predicts severity of gut graft-versus-host disease (GVHD) in children

The clinical evaluation and management of gut GVHD is a significant challenge in pediatric HSCT. It is often difficult to obtain pathological evidence to confirm diagnosis and/or to determine response to treatment. The severity of the disease itself may not be related to just the classic symptom of diarrhea. The objectives of this study were to prospectively evaluate patients with suspected gut GVHD for PLE as measured by AATC in stools at two different times for each patient and to compare the severity of the PLE with the severity of clinical acute gut GVHD. Thirteen patients were suspected of gut GVHD by clinical criteria (diarrhea > 10 mL/kg/24 h); one patient was excluded for being unable to complete the stool collection. Therefore, 12 patients, 10 boys and two girls, were studied. Median stool volume was 27.5 mL/kg/day (range 10.1-109.0).The median age at BMT was 11.1 yr (range 3.9-17.0 yr). All patients had negative stool electron microscopy for viruses and cultures for C. difficile on their first collection. Nine patients (75%) had two 24-h stool collections performed at a median of eight days apart (range 7-14 days). At the time of the first collection, six patients had ≥ stage 2 acute gut GVHD, and at second collection, four patients had ≥ stage 2 gut GVHD and four collections were of non-diarrheal stool (hence treatment response). Median AATC from all 21 collections was 19.0 mL/day (range 3.0-561.0), and levels >22 mL/day indicate the diagnosis of PLE. The four children initially suspected of GVHD but who had a negative biopsy completed a total of five collections with a median AATC of 5.0 mL/day (range 3.0-16.0) vs. a median of 33.5 for the remainder of the collections (range 3-561). Stage of gut GVHD correlated with elevated AATC and with stool volume. AATC > 22 mL/day showed a sensitivity of 70% and specificity of 82% for significant gut GVHD (≥ stage 2). Seven stool collections were taken at ≥ stage 3 gut GVHD; six of those seven patients were positive for PLE. Larger stool volumes were more predictive, and five collections with stool volumes >30 mL/kg/day were positive for PLE. We conclude that a significant positive correlation exists between the severity of PLE and the stage of gut GVHD (p < 0.04), particularly obvious in patients with stages 2-4 GVHD (p = 0.03). Despite the small number of patients recruited, this study emphasizes the need to consider PLE as a useful aspect of the clinical picture. We suggest that in order to see a response to therapy and therefore a decrease in AATC, clinicians should wait at least 2 wk from the initiation of therapy before repeating AATC test. In light of the significant morbidity and mortality associated with ≥ stage 2 gut GVHD, and as an important therapeutic decision for these patients, one may consider evaluating AATC if a biopsy is not an option.

Hematopoietic stem-cell transplantation following solid-organ transplantation in children

Reports of hematopoietic stem-cell transplantation (HSCT) following solid-organ transplantation have been described in adults mainly as case reports. These reports demonstrate feasibility but likely do not reflect true outcomes due to a positive reporting bias. We report herein the outcomes of all our pediatric recipients of allogeneic HSCT following previous solid-organ transplantation between 2000 and 2009. Four children were identified. Two patients underwent heart transplantation followed by cord-blood allogeneic HSCT for T-cell lymphoma/post transplant lymphoproliferative disease (PTLD) and two patients underwent liver transplantation followed by living-donor allogeneic HSCT for severe aplastic anemia (SAA). The mean time between transplants was 4.2 years (range 1.5-6 years). All patients engrafted; however, all patients died from 37 days to 1 year after HSCT. Causes of death included infections (n=2), multi-organ failure (n=1) and solid-organ graft rejection (n=1). Though three patients survived beyond day+100, multiple complications were observed including EBV re-activation followed by EBV-positive PTLD (n=1) and five episodes of severe infections. The patients transplanted for lymphoma did not have evidence of recurrence at last follow-up. Although feasibilty has been shown with this cohort, we conclude that allogeneic HSCT in immunosuppressed patients following solid-organ transplantation remains a very high risk procedure that results in severe morbidity and mortality in children.

Cord stem-cell transplantation in Ontario: do we need a public bank?

It has been 21 years since the first successful use of umbilical cord blood as a source of donor cells for hematopoietic stem cell transplantation (HSCT). Over those years, cord blood transplantation (CBT) has shown marked success as an effective modality in the treatment of children and adults with hematologic malignancies, marrow failure, immunodeficiency, hemoglobinopathy, and inherited metabolic diseases. Furthermore, transplantation without full human leukocyte antigen (HLA) matching is possible and, despite a lower incidence of graft-versus-host disease, graft-versus-leukemia effect is preserved. More than 20,000 cbts have been performed worldwide. Ontario is the most populated province in Canada, and its cbt numbers have increased dramatically in recent years, but most of the umbilical cord blood units are purchased from unrelated international registries. There is no public cord bank in Ontario, but there is a private cord banking option, and notably, Ontario has the largest number of live births in Canada [approximately 40% of all Canadian live births per year occur in Ontario (Statistics Canada, 2007)]. In this brief review, the pros and cons of private and public cord banking and the feasibility of starting an Ontario public cord bank are discussed.

A comparison of the outcomes of children with acute myelogenous leukemia in either first or second complete remission (CR1 vs CR2) following allogeneic hematopoietic stem cell transplantation at a single transplant center

We reviewed 70 consecutive children with AML who received hematopoietic stem cell transplantation (HSCT) in our institution between 1994 and 2005. Forty-seven children were transplanted in CR1 and 23 were transplanted in CR2. BU/CY was the most common pretransplant conditioning regimen for CR1 patients and a TBI-based conditioning regimen was the most common regimen for CR2 patients. Most patients transplanted in CR1 (81%) received related donor HSCT, whereas most of the CR2 patients (74%) received unrelated donor HSCT. Expectedly, there was a significant increase in acute GVHD incidence in CR2 patients (40 vs 25% for grades I-II and 30 vs 10% for grades III-IV; P=0.02) and a significant increase in transplant-related mortality (38 vs 11%; P=0.01). Although the difference between 3-year EFS for CR1 and CR2 was not statistically significant, there was a significantly superior 3-year overall survival for CR1 patients (74 vs 51%; P=0.05). Children with relapsed AML who achieve and maintain remission until HSCT, have a reasonable survival, but the outcome of children receiving HSCT in CR1 remains superior.

Unsuccessful treatment attempt: cord blood stem cell transplantation in a patient with Niemann-Pick disease type A

Niemann-Pick disease type A (NP-A; OMIM 257200) is an autosomal recessive lysosomal storage disorder caused by deficiency of acid sphingomyelinase and resulting in accumulation of sphingomyelin, unesterified cholesterol, and other complex lipids in many tissues. It is characterized by failure to thrive, hepatosplenomegaly, and a rapidly progressive neurodegenerative course culminating in death by 3 years of age. There is no known effective treatment. We report the case of a prenatally diagnosed girl who underwent cord blood stem cell transplantation (CBSCT) at 3 months of age. She was neurologically intact at the time of CBSCT. Hepatosplenomegaly, was detected at 6 weeks of age; the splenomegaly resolved following CBSCT. Recovery was complicated by graft-versus-host disease. She subsequently developed and continues to show marked global developmental delay, generalized hypotonia, and signs of neurological regression, despite continued engraftment. Bilateral cherry red spots were detected at 10 months of age, 7 months post-CBSCT. Although she is doing better than her affected brother, she shows little overall benefit from CBSCT.

Graft-versus-leukemia effect in hematopoietic stem cell transplantation for pediatric acute lymphoblastic leukemia: significantly lower relapse rate in unrelated transplantations

To determine graft-versus-leukemia (GVL) effect after hematopoietic stem cell transplantation (HSCT), we studied the outcome of consecutive children with acute lymphoblastic leukemia (ALL) who received fully matched marrow allografts comparing relapse rate post HSCT between matched sibling donor (MSD) and matched unrelated donor (MUD) recipients. Furthermore, we estimated event-free survival (EFS) on the basis of the occurrence of acute graft-versus-host disease (aGVHD). Between 1998 and 2006 we performed 37 fully MSD and 36 fully MUD HSCTs. All patients received identical conditioning regimens with cyclophosphamide/total body irradiation and dual GVHD prophylaxis with cyclosporine (CSA) and methotrexate (MTX). Three-year cumulative incidence of relapse for the MSD and MUD groups were 55.6+/-12.3 and 22.0+/-8.1%, respectively (P=0.03). Three-year EFS according to aGVHD was 32.7+/-12.2% for no aGVHD, 61.2+/-10.0% for grade I-II aGVHD and 66.7+/-11.1% for grade III-IV aGVHD. Three-year EFS and overall survival (OS) were 40.5+/-11.6, 49.1+/-9.5% for the MSD group, and 60.5+/-8.7, 62.3+/-8.4% for the MUD group. In children with ALL receiving dual GVHD prophylaxis, relapse rate is significantly higher among recipients of MSD compared to MUD transplantation, which may in part be attributed to a better GVL effect with the unrelated graft.

Comparative outcome of hematopoietic stem cell transplantation for pediatric acute lymphoblastic leukemia following cyclophosphamide and total body irradiation or VP16 and total body irradiation conditioning regimens

To compare the outcome of hematopoietic stem cell transplantation (HSCT) in pediatric acute lymphoblastic leukemia (ALL) conditioned with two different regimens: (1) single dose of VP16 (60 mg/kg over 4 h) and total body irradiation (TBI; 1200 cGy, in six fractions) or (2) Cyclophosphamide 50 mg/kg over 1 h daily for 4 days followed by the same dose of TBI. One hundred and seven children with ALL received fully matched HSCT from 1990 to 2003 in the Hospital for Sick Children, Toronto. All received cyclosporin A and a short course of methotrexate for graft-versus-host disease (GVHD) prophylaxis. The VP16 group, there were 36 matched related donor transplants (MRD) and 26 matched unrelated donor transplants (MUD), and in the cyclophosphamide group there were 23 MRD and 22 MUD transplants. Neutrophil engraftment occurred at a median of 18 and 17 days for the VP16/TBI and the CY/TBI groups, respectively. The 3 year event-free survival and overall survival were 47 +/- 7 and 55 +/- 7% for those receiving VP16/TBI, and 51 +/- 8 and 53 +/- 8% for the CY/TBI group. There were no significant differences in the prevalence of acute or chronic GVHD and transplant-related mortality between the two groups. Both VP16/FTBI and CY/FTBI regimen are equally effective regimens.

Risk of ventriculoperitoneal shunt infections due to gastrostomy feeding tube insertion in pediatric patients with brain tumors

OBJECTIVE

To determine the risk of ventriculoperitoneal (VP) shunt infections after percutaneous retrograde gastrostomy feeding tube (GT) placement in children with brain tumors.

PATIENTS AND METHODS

All children (age 0-18 years) with primary brain tumors diagnosed and treated at the Hospital for Sick Children, Toronto, Canada, were subjected to a retrospective analysis. Two groups were identified: the study group included children with a VP shunt and a GT; the control group included children with VP shunts only. Each study patient was matched with 2 controls to compare the rate of infections (cohort comparative study).

RESULTS

There were 1,167 children diagnosed and treated with primary brain tumors during the study period (1988-2003); 174 (15%) had a VP shunt and 23 (2%) children had both, a VP shunt and a GT. In the study group (n=17), GTs were inserted at a median time of 80 days (range 6-204 days) after VP shunts. VP shunt infection rate was 23.5% (4/17) compared to 8.8% (3/34) in the control group (OR 3.18; 95% CI 0.622-16.54, p=0.16). Three (75%) of the infection episodes in the study group presented with an ascending VP shunt infection directly related to the GT insertion or manipulation in the first 6 weeks. These GTs were inserted at 13, 47 and 49 days after VP shunt insertion.

CONCLUSION

Placement of percutaneous retrograde GTs, in the acute phase, in children with brain tumors and VP shunts may increase the risk of ascending meningitis especially if there are early GT-related complications.

Life-threatening pulmonary hemorrhages post bone marrow transplantation in Hurler syndrome. Report of three cases and review of the literature

Hurler syndrome (MPS-IH) is an autosomal recessive mucopolysaccharide storage disorder caused by deficiency of lysosomal alpha-L-iduronidase (IDU) enzyme activity. This results in accumulation of heparan sulfate and dermatan sulfate substances. Untreated children develop progressive developmental deterioration and multisystem morbidity with a median survival of 5 years. Allogeneic bone marrow transplantation (BMT) is the only long-lasting treatment that ameliorates or halts the aggressive course of the disease. Pulmonary hemorrhage (PH) is an unusual complication of BMT and has not been previously reported in MPS-IH post-BMT. We report three children with MPS-IH with life-threatening PH around the time of engraftment. All needed intensive-care support and one child developed recurrent PH that required prolonged ventilation.

The effect of prelung transplant clinical status on post-transplant survival of children with cystic fibrosis

The aim of this study was to determine whether transplanting paediatric cystic fibrosis (CF) patients later in the course of their disease was detrimental to their post-transplant survival. Data was collected from 51 children with CF undergoing lung or heart-lung transplantation May 1988-March 1999. The following risk factors were tested by Cox proportional hazards modelling: age at transplant; sex; donor/recipient sex mismatch; donor/recipient cytomegalovirus (CMV) mismatch; cold and warm graft ischaemic times; and donor age. Pretransplant forced expiratory volume in one second (FEV1), minimum oxygen saturation obtained during 12 min walk (Sa,O2min), and a survival probability score (SP) calculated from FEV1, age adjusted resting heart rate, age, sex, blood haemoglobin (Hb), and serum albumin were then added to the model. None of the risk factors were significantly correlated with death during the study period. No evidence that clinical status prior to transplant has any effect upon the post-transplant survival of children with cystic fibrosis was found.