Umbilical Cord Blood Transplantation for Fanconi Anemia With a Special Focus on Late Complications: a Study on Behalf of Eurocord and SAAWP-EBMT

Hematopoietic cell transplantation (HCT) remains the sole available curative treatment for Fanconi anemia (FA), with particularly favorable outcomes reported after matched sibling donor (MSD) HCT. This study aimed to describe outcomes, with a special focus on late complications, of FA patients who underwent umbilical cord blood transplantation (UCBT). In this retrospective analysis of allogeneic UCBT for FA performed between 1988 and 2021 in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers, a total of 205 FA patients underwent UCBT (55 related and 150 unrelated) across 77 transplant centers. Indications for UCBT were bone marrow failure in 190 patients and acute leukemia/myelodysplasia in 15 patients. The median age at transplantation was 9 years (range, 1.2 to 43 years), with only 20 patients aged >18 years. Among the donor-recipient pairs, 56% (n = 116) had a 0 to 1/6 HLA mismatch. Limited-field radiotherapy was administered to 28% (n = 58) and 78% (n = 160) received a fludarabine (Flu)-based conditioning regimen. Serotherapy consisted of antithymocyte globulin (n = 159; 78%) or alemtuzumab (n = 12; 6%). The median follow-up was 10 years for related UCBT and 7 years for unrelated UCBT. Excellent outcomes were observed in the setting of related UCBT, including a 60-day cumulative incidence (CuI) of neutrophil recovery of 98.1% (95% confidence interval [CI], 93.9% to 100%), a 100-day CuI of grade II-IV acute graft-versus-host disease (GVHD) of 17.3% (95% CI, 9.5% to 31.6%), and a 5-year CuI of chronic GVHD (cGVHD) of 22.7% (95% CI, 13.3% to 38.7%; 13% extensive). Five-year overall survival (OS) was 88%. In multivariate analysis, none of the factors included in the model predicted a better OS. In unrelated UCBT, the 60-day CuI of neutrophil recovery was 78.7% (95% CI, 71.9% to 86.3%), the 100-day CuI of grade II-IV aGVHD was 31.4% (95% CI, 24.6% to 40.2%), and the 5-year CuI of cGVHD was 24.3% (95% CI, 17.8% to 32.2%; 12% extensive). Five-year OS was 44%. In multivariate analysis, negative recipient cytomegalovirus serology, Flu-based conditioning, age <9 years at UCBT, and 0 to 1/6 HLA mismatch were associated with improved OS. A total of 106 patients, including 5 with acute leukemia/myelodysplasia, survived for >2 years after UCBT. Nine of these patients developed subsequent neoplasms (SNs), including 1 donor-derived acute myelogenous leukemia and 8 solid tumors, at a median of 9.7 years (range, 2.3 to 21.8 years) post-UCBT (1 related and 8 unrelated UCBT). In a subset of 49 patients with available data, late nonmalignant complications affecting various organ systems were observed at a median of 8.7 years (range, 2.7 to 28.8 years) post-UCBT. UCB is a valid source of stem cells for transplantation in patients with FA, with the best results observed after related UCBT. After unrelated UCBT, improved survival was observed in patients who underwent transplantation at a younger age, with Flu-based conditioning, and with better HLA parity. The incidence of organ-specific complications and SNs was relatively low. The incidence of SNs, mostly squamous cell carcinoma, increases with time. Rigorous follow-up and lifelong screening are crucial in survivors of UCBT for FA.

HLA-haploidentical stem cell transplantation in children with inherited bone marrow failure syndromes: A retrospective analysis on behalf of EBMT severe aplastic Anemia and pediatric diseases working parties

Haploidentical stem cell transplantation (haplo-SCT) represents the main alternative for children with inherited bone marrow failure syndrome (I-BMF) lacking a matched donor. This retrospective study, conducted on behalf of the EBMT SAAWP and PDWP, aims to report the current outcomes of haplo-SCT in I-BMFs, comparing the different in vivo and ex vivo T-cell depletion approaches. One hundred and sixty-two I-BMF patients who underwent haplo-SCT (median age 7.4 years) have been registered. Fanconi Anemia was the most represented diagnosis (70.1%). Based on different T-cell depletion (TCD) approaches, four categories were identified: (1) TCRαβ+ /CD19+ -depletion (43.8%); (2) T-repleted with post-transplant Cyclophosphamide (PTCy, 34.0%); (3) In-vivo T-depletion with ATG/alemtuzumab (14.8%); (4) CD34+ positive selection (7.4%). The cumulative incidences (CI) of neutrophil and platelet engraftment were 84% and 76% respectively, while that of primary and secondary graft failure was 10% and 8% respectively. The 100-day CI of acute GvHD grade III-IV(95% CI) was 13%, while the 24-month CI of extensive chronic GvHD was 4%. After a median follow-up of 43.4 months, the 2-year overall survival(OS) and GvHD/Rejection-free Survival (GRFS) probabilities are 67% and 53%, respectively. The TCR CD3+ αβ+ /CD19+ depletion group showed a significantly lower incidence of both acute and chronic GvHD and higher OS (79%; p0.013) and GRFS (71%; p < .001), while no significant differences in outcomes have been observed by different diagnosis and conditioning regimens. This large retrospective study supports the safety and feasibility of haplo-SCT in I-BMF patients. TCRαβ+ /CD19+ depletion offers higher chances of patients' survival, with a significantly lower risk of severe a- and c-GvHD in I-BMFs compared to other platforms.

Is Mixed Chimerism Post-allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Acute Lymphoid Leukemia a Prognostic Factor for Relapse?

Hematopoietic stem cell transplantation (HSCT) has been considered curative for children with high-risk acute leukemia (ALL), offering better survival. Short tandem repeat has been used as a marker of chimerism status after HSCT. The appearance of recipient cells >1% post-allogeneic stem cell transplant is defined as mixed chimerism (MC). Chimeric studies post-HSCT are dynamic. This study aimed to investigate the significance of recipient cells in post-HSCT pediatric ALL patients as a predictor of relapse of their primary disease. The rate of MC was 51.4% (19 out of 37 recipients). It was 48.6% (n = 18) during Day+100 and 12.9% (4 out of 31 recipients) during post-Day+100 follow-up until two years. No significant association was noted between MC and all grade overall acute graft-versus-host disease. A mortality rate of 35.1% (n = 13) and a median follow-up of 56.9 months (95% CI: 39.7-74.2) were observed for all but four (16.7%) of the survivors in remission. Regarding causes of death, transplant-related mortality was recorded in only 2 of 13 expired patients (15.4%); both succumbed to sepsis. No significant association was found between MC and primary causes of death. The cumulative probability of five-year overall survival and event-free survival was not found to be statistically significantly different for MC (≤1.0% vs. > 1.0%). In conclusion, our data did not show MC testing alone as an effective prognostic marker for detecting relapse; molecular and flow cytometric analyses should be considered in children with ALL post-HSCT for monitoring relapse.

Clofarabine in Pediatric Acute Relapsed or Refractory Leukemia: Where Do We Stand on the Bridge to Hematopoietic Stem Cell Transplantation?

Background

Despite pronounced improvement in overall survival (OS) in pediatric leukemia, a proportion of patients continue to suffer from lack of response or relapse, and the management of such patients is exceedingly difficult. Immunotherapy and engineered chimeric antigen receptor (CAR) T-cell therapy have shown promising results in the course of relapsed or refractory acute lymphoblastic leukemia (ALL). However, conventional chemotherapy continues to be utilized for re-induction purposes whether independently or in combination with immunotherapy.

Methods

Forty-three pediatric leukemia patients (age < 14 years at diagnosis) consecutively diagnosed at our institution and got treated with clofarabine based regimen at a single tertiary care hospital between January 2005 and December 2019 were enrolled in this study. ALL comprised of 30 (69.8%) patients of the cohort while the remaining 13 (30.2%) were with acute myeloid leukemia (AML).

Results

Post-clofarabine bone marrow (BM) was negative in 18 (45.0%) cases. Overall clofarabine failure rate was 58.1% (n = 25) with 60.0% (n = 18) in ALL and 53.8% (n = 7) in AML (P = 0.747). Eighteen (41.9%) patients eventually underwent hematopoietic stem cell transplantation (HSCT); 11 (61.1%) were from ALL group and remaining seven (38.9%) were AML (P = 0.332). Three- and 5-year OS of our patients was 37.7±7.6% and 32.7±7.3%. There was a trend of better OS for ALL patients compared to AML (40.9±9.3% vs. 15.4±10.0%, P = 0.492). Cumulative probability of 5-year OS was significantly better in transplanted patients (48.1±12.1% vs. 21.4±8.4%, P = 0.024).

Conclusions

Though almost 90% of our patients proceeded to HSCT with complete response post-clofarabine treatment, yet clofarabine-based regimens are associated with the significant burden of infectious complications and sepsis-related deaths.

Can the bone marrow harvest volume be reduced safely in hematopoietic stem cell transplantation with pediatric sibling donors?

Background

Reduced harvest volumes in pediatric donors appear to have the potential to reduce donorassociated risks while maintaining engraftment in recipients; however, the allowable harvest volume reduction remains undefined.

Methods

We retrospectively analyzed the data pairs of 553 bone marrow (BM) harvests from pediatric (age at harvest <18 yr) sibling donors and clinical outcomes of 553 pediatric (age at infusion <14 yr) transplant-naïve recipients to assess the optimal BM harvest volume needed from pediatric donors to obtain the desired CD34+ cell count (≥3.0×10⁶ per kg of recipient weight) and to study its impact on the clinical outcomes of transplantation in pediatric recipients.

Results

506 (95.3%) donor-recipient pairs met the median CD34+ cell count of 6.4×10⁶ per kg of recipient weight (range, 1.2-33.8×10⁶) in donors younger than 5 years at harvest, 4.7×10⁶ (range, 0.3-28.5×10⁶) in donors aged 5-10 years and 2.1×10⁶ (range, 0.3-11.3×10⁶) in donors older than 10 years (P<0.001).

Conclusion

The infused CD34+ cell dose (×10⁶ cells/kg of recipient weight) had no impact on GRFS; however, a CD34+ cell dose of >7×10⁶ cells/kg of recipient weight did not improve hematopoietic recovery.

Outcomes of blood and marrow transplantation in children less than 2-years of age: 23 years of experience at a single center

Objectives

Allogeneic hematopoietic cell transplantation (Allo-HCT) is a curative option for children with various malignant and non-malignant diseases. Most reports studied all age groups amongst children. Herein we analyzed our data in children transplanted at or less than 2-years of age.

Patients and methods

We reviewed medical charts of 618 patients who underwent 666 transplantation at our center between 1993 and 2015. There were 340 boys and 278 girls. Median age was 0.7 years (range 0.04-2). Stem cell source was bone marrow (BM) in 492 (73.9%), unrelated umbilical cord blood (UCB) in 161 (24.2%) followed by peripheral blood stem cell (PBSC) in 13 (2%) patients. Matched siblings were the most common donors (n = 356, 53.5%), followed by unrelated (n = 161, 24.2%) with haploidentical family member donors in 29 (4.4%) transplants. Disease groups were categorized as benign hematology (Thalassemia, Fanconi, Aplastic anemia etc.), benign neoplasm (Langerhans cell histiocytosis, Hemophagocytic Lymphohistiocytosis etc.), non-neoplasms (metabolic disorders, immunodeficiency disorders etc.) and Leukemia/lymphomas (myeloid and lymphoid malignancies etc.).

Results

Cumulative incidence of acute GvHD (I-IV) was 31.5% (n = 210) and grade III-IV GvHD was 8.7% (n = 58). At median follow-up of 115.1 months, the cumulative probability of overall survival (OS) at 5 years was 70.0% ± 1.9%. Our mortality rate was 31.2% (n = 193). The five-year OS was significantly better in patients transplanted for benign hematological disorders (P = .001). Patients transplanted using BM/PBSC as source of stem cells fared significantly better compared to those in which CB was used (P<.001). Post-transplant graft failure remains the leading cause requiring further transplants in this age group. In conclusion, the cumulative probability of OS at 5 years was about 70.0% for all with an OS of 61% in our haploidentical recipients.

Conclusion

Analyzing our institutional data over time has enabled us to develop tentative strategies to minimize transplant related toxicities in very young children who are candidates for allo-HCT.

Outcome of pediatric chronic myeloid leukemia with management focusing on the monitoring of BCR-ABL fusion gene transcript levels

Background and objective

Clinical, laboratory and outcome data were reviewed for pediatric patients who were diagnosed with chronic myeloid leukemia (CML) and managed at two tertiary care hospitals in Saudi Arabia, between January 2011 and December 2017 to assess the response to tyrosine kinase inhibitors (TKI) focusing on the monitoring of BCR-ABL fusion gene transcript levels and to look at the overall outcome.

Methods

CML patients were identified based on the cytogenetic and molecular results.

Results

Twelve pediatric patients diagnosed with CML at a median age of 8.4 year; treated with TKI as first-line therapy, 11 (91.7%) patients were started with imatinib (first-generation TKI), while one received dasatinib (second-generation TKI) due to his three-way Philadelphia chromosome sensitivity. Eight patients (72.7%) starting on imatinib were switched to dasatinib (six patients due to drug resistance, and two patients due to intolerance of Imatinib) and two patients (25%) of whom had already achieved major molecular response (MMR) on Imatinib. Response rate to imatinib in terms of achieving MMR as first-line therapy was achieved in five out of 11 patients (45.5%) and only three of them continued to maintain their MMR. Six out of eight patients who were switched to dasatinib achieved MMR. Two patients underwent hematopoietic stem cell transplant (SCT): one due to blast crisis and one due to the side effects of TKI. With a median follow-up time of 78 months (range, 40.5–108), all of our patients were alive at last update.

Conclusion

We report an excellent outcome with an overall survival (OS) of 100% at 5-year and disease-free survival (DFS) of 91.7% (8.0%). All our patients achieved MMR and only one patient had loss of MMR on follow-up. Eight patients (66.7%) achieved complete molecular response (CMR).

Hematopoietic Stem Cell Transplantation Stabilizes Cerebral Vasculopathy in High-Risk Pediatric Sickle Cell Disease Patients: Evidence From a Referral Transplant Center

Background

Methods

Results

Conclusions

Pediatric high risk neuroblastoma with autologous stem cell transplant - 20 years of experience

BACKGROUND AND OBJECTIVE

Neuroblastoma is the most common extracranial solid tumor found in pediatric patients. High-risk neuroblastoma (HR-NBL) can be characterized by metastasis, age, and other tumor characteristics that result in an adverse outlook for this patient cohort. The standard of care includes induction chemotherapy, surgery, followed by stem cell autologous transplant (ASCT), and later, antidisialoganglioside (anti-GD2) antibodies. In this study, we provide the survival and toxicity data of our HR-NBL patients treated with a single ASCT.

METHODS

We retrospectively analyzed pediatric HR-NBL patients treated with single ASCT after a carboplatin, etoposide, and melphalan (CEM) regimen in our institution between January 1993 and December 2014.

RESULTS

There were 99 evaluable patients with male predominance. The median age at diagnosis was 3 years. Most of our HR-NBL patients were stage 4 (88%). All patients received ASCT. Peripheral blood was the graft source in 58% of the patients. Time for hematological count recovery with bone marrow as a graft source was prolonged but not statistically significant when compared with PBSCs. Of all the patients, 58% received radiation therapy to residual disease. Overt secondary leukemia was not seen in any of these patients. Three-year overall survival (OS) was 68.5% ± 5.2% and the 3-year event-free survival (EFS) was (48.3% ± 5.2%).

CONCLUSION

Our HR-NBL patients tolerated high-dose chemotherapy well followed by single autologous stem cell transplant. Tandem transplant is a feasible option in our patient cohort. Apart from secondary solid tumors, there were no long-term complications seen.

Genetic and clinical characteristics of pediatric patients with familial hemophagocytic lymphohistiocytosis

Background

Our study was designed to investigate the frequencies and distributions of familial hemophagocytic lymphohistiocytosis (FHL) associated genes in Saudi patients.

Methods

FHL associated gene screening was performed on 87 Saudi patients who were diagnosed with hemophagocytic lymphohistiocytosis (HLH) between 1995 and 2014. The clinical and biochemical profiles were also retrospectively captured and analyzed.

Results

Homozygous mutations and mono-allelic variants were identified in 66 (75.9%) and 3 (3.5%) of the study participants, respectively. STXBP2 was the most frequently mutated gene (36% of patients) and mutations in STXBP2 and STX11 accounted for 58% of all FHL cases and demonstrated a specific geographical pattern. Patients in the FHL group presented at a significantly younger age than those belonging to the unknown-genetics group (median, 3.9 vs. 9.4 mo; P=0.005). The presenting clinical features were similar among the various genetic groups and the 5-year overall survival (OS) was 55.4% with a 5.6 year median follow-up. Patients with PRF1 mutations had a significantly poorer 5-year OS (21.4%, P=0.008) and patients undergoing hematopoietic stem cell transplant (72.4%) had a significantly better 5-year OS (66.5% vs. 0%, P=0.001).

Conclusion

Our study revealed the predominance of the STXBP2 mutations in Saudi patients with FHL. A genetic diagnosis was possible in 80% of the cohort and our data showed improved survival in FHL patients who underwent hematopoietic stem cell transplant.

Haplo-identical or mismatched unrelated donor hematopoietic cell transplantation for Fanconi anemia: Results from the Severe Aplastic Anemia Working Party of the EBMT

Allogeneic hematopoietic cell transplantation (HCT) is the only curative option for bone marrow failure or hematopoietic malignant diseases for Fanconi anemia (FA) patients. Although results have improved over the last decades, reaching more than 90% survival when a human leukocyte antigen (HLA)-identical donor is available, alternative HCT donors are still less reported. We compared HCT outcomes using HLA-mismatched unrelated donors (MMUD; n = 123) or haplo-identical donors (HDs), either using only in vivo T cell depletion (n = 33) or T cells depleted in vivo with some type of graft manipulation ex vivo (n = 59) performed for FA between 2000 and 2018. Overall survival (OS) by 24 months was 62% (53-71%) for MMUD, versus 80% (66-95%) for HDs with only in vivo T cell depletion and 60% (47-73%) for HDs with in vivo and ex vivo T cell depletion (p = .22). Event-free survival (EFS) was better for HD-transplanted FA patients with only in vivo T cell depletion 86% (73-99%) than for those transplanted from a MMUD 58% (48-68%) or those with graft manipulation 56% (42-69%) (p = .046). Grade II-IV acute graft-versus-host disease (GVHD) was 41% (MMUD) versus 40% (HDs with no graft manipulation) versus 17% (HDs with T cell depleted graft), (p = .005). No differences were found for the other transplant related outcomes. These data suggest that HDs might be considered as an alternative option for FA patients with better EFS using unmanipulated grafts.

Prevalence and risk factors of oral mucositis in paediatric patients undergoing haematopoietic stem cell transplantation

Background

A complete understanding of oral mucositis (OM) is crucial to develop appropriate interventions to aid in the successful overall health outcome of paediatric patients undergoing haematopoietic stem cell transplantation (HSCT).

Aims

This study aimed at determining the prevalence and severity of OM and at identifying the predictive factors that might aggravate OM at one‐week, two‐week and three‐week post‐HSCT.

Methods

This retrospective, hospital‐based study reviewed the medical records of 170 paediatric patients, summarising the patients’ characteristics using descriptive statistics. Binary logistic regression was used to identify factors associated with the development of OM.

Results

At one‐week post‐HSCT, 41% of 140 patients (n = 49) had developed OM, this was reduced at two‐week (n = 36, 33%) and three‐week (n = 13, 19%) post‐HSCT. Univariate logistic regression revealed that patients with cancer (OR = 0.16, 95% CI = 0.05–0.54; p‐value = .003) had a significantly lower prevalence of OM. Younger patients with an average age of 7.9 years old (OR = 0.85, 95% CI = 0.75–0.97; p‐value = 0.013) and the presence of GvHD (OR = 2.37, 95% CI = 1.03–5.45, p‐value = 0.042) were significantly related to a higher prevalence of OM. Multivariable logistic regression confirmed that the risk of OM is lower in patients with cancer compared to those with immunodeficiency syndromes or hereditary blood diseases (OR = 0.18, 95% CI = 0.04–0.77; p‐value = .021).

Conclusions

This study identified a significantly lower prevalence of OM in patients with cancer compared to other conditions and that young recipients and those who developed GvHD were more likely to have OM.

Experience of treating pediatric hepatoblastoma at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia - Timely surgical intervention playing a key role

Background

Many studies have demonstrated that outcome in patients with hepatoblastoma is determined by tumor resectability and the presence or absence of metastatic disease.

Purpose

To evaluate and disseminate information on diagnosis, treatment, and outcome of hepatoblastoma patients at a tertiary care hospital in Saudi Arabia.

Patients and methods

Twenty-four pediatric patients with hepatoblastoma were treated at our institution between January 2005 and December 2012. The majority of our patients were stage III and above, while one-third of them presented with metastatic disease. Four (16.7%) had vascular invasion. Two-thirds of our patients (n = 16, 66.7%) had alpha-fetoprotein (AFP) level above 100,000 ng/mL. Twenty-one patients underwent surgery; two had upfront surgery before getting any chemotherapy, and 15 had surgery on schedule after pre-operative chemotherapy. Four patients had delayed surgery as the tumor was not resectable and received extra cycles of chemotherapy. Chemotherapy regimens used were based on SIOPEL study protocols until 2011 and Children’s Oncology Group (COG) protocol from 2012 onwards. Relapse, progressive disease, or death from any cause were defined as events.

Results

Five-year overall survival (OS) of the cohort over a median follow-up time of 56.1 months was 70.6% ± 9.4% with seven (29.2%) events of mortality. No significant difference was found for age at diagnosis (less than 2 years vs. more), stage of disease, AFP levels (less than 100,000 vs. more), vascular invasion, or presence of metastatic disease at presentation in terms of OS. However, children receiving upfront or scheduled as-per-protocol surgery fared better than those who had delayed surgery (as the tumor was not resectable and they received extra cycles of chemotherapy) or did not undergo any surgery (P-Value .001).

Conclusion

Favorable survival outcome could be achieved with complete tumor excision and adjuvant chemotherapy. Inability to perform surgical excision was the single most important predictor of mortality in our patients.

Travel burden and geographic access to health care among children with cancer in Saudi Arabia

Background

Travel burden has a substantial psychosocial impact and financial strain on childhood cancer patients and their families.

Aims

To study the geographic distribution of childhood cancer and assess the travel burden for care in Saudi Arabia.

Methods

This was a cross-sectional multi-institutional study that enrolled 1657 children with cancer who were diagnosed between 2011 and 2014. Cancer type/stage, city/region of residence, and city/region of treating centre were recorded. Travel burden was measured based on a 1-way distance in kilometres from the city centre to the treatment institution. This study was supported by Sanad Children's Cancer Support Association.

Results

Diagnosis was leukaemia (45.2%), non-CNS solid tumours (30.2%), lymphoma (12.3%), CNS tumours (11.8%) and histiocytosis (0.5%). Childhood cancer centres were in the same city as where the patients lived in 652 (39.3%) cases, same region but different city in 308 (18.6%), different regions in 613 (37%), and not known in 84 (5.1%). The mean 1-way travel distance for patients who lived in different regions was 790 (range, 116-1542) km. A total of 536 (32%) patients lived ≥ 400 km and 216 (13%) > 1000 km from the treatment centre. Among 642 patients with acute lymphoblastic leukaemia who required 2-3 years of therapy, 197 (31%) lived ≥ 400 km and 94 (15%) >1000 km from the treatment centre.

Conclusions

Nearly two thirds of patients with childhood cancer lived in different cities than the treatment centres, including one third of patients who lived ≥ 400 km away. There is a need to develop strategies to improve access to childhood cancer care.

Hematopoietic stem cell transplantation in Saudi Arabia between 1984 and 2016: Experience from four leading tertiary care hematopoietic stem cell transplantation centers

Saudi Arabia is the largest of the Arabian Gulf countries with a total population of 33.41 million as of 2017. This report summarizes the experience from four leading tertiary care hematopoietic stem cell transplantation (HSCT) centers in Saudi Arabia representing more than 90% of all HSCTs performed in the country. Between 1984 and 2016, a total of 6,184 HSCTs were performed. Of these, 3,586 HSCTs were performed in adults and 2,598 HSCTs were performed in pediatric patients. Malignancy was the main indication for transplantation (47%). While most transplants were performed from an identical sibling donor, HSCTs from cord blood, unrelated and, more recently, haploidentical donors have also been performed. Relative shortage of HSCT bed capacity is perceived to be a limiting factor in Saudi Arabia. Lately, more HSCT centers are emerging with rapid growth, which may significantly improve the access to HSCT in the country in the near future.

Frequency of pathogenic/likely pathogenic germline variants in cancer-related genes among children with acute leukemia in Saudi Arabia

BACKGROUND

The frequency of pathogenic/likely pathogenic (P/LP) germline mutations in cancer-related genes among children with cancer in highly consanguineous populations is not well studied.

METHODS

Whole-exome sequencing of germline DNA was performed in 60 children with acute leukemia. We used the St. Jude Pediatric Cancer Variant Pathogenicity Information Exchange (PeCanPIE) data portal for the classification of germline variants by the St. Jude Medal Ceremony pipeline.

RESULTS

Fifty-seven patients had acute lymphoblastic leukemia (ALL) and three patients had acute myeloid leukemia. Parental consanguinity was present in 27 (45%) patients. All patients were of Arab ancestry. Three patients (5%) had a history of cancer in their siblings. Five patients (8.3%) had P/LP germline mutations in cancer-related genes. Three patients with B-ALL had heterozygous pathogenic mutations in TP53, BRCA1, and BRCA2; one patient with B-ALL had homozygous pathogenic mutation in PMS2; and one patient with T-ALL had LP homozygous mutation in AK2 that was associated with reticular dysgenesis. Among patients who had history of parental consanguinity, three (11%) had P/LP germline mutations compared with two (8%) in the absence of parental consanguinity. Fourteen (23%) patients had gold medal variants in cancer-related genes, 13 were heterozygous, and one was homozygous. Silver medal variants were present in 35 (58%) patients; all were heterozygous except one homozygous.

CONCLUSIONS

Children with acute leukemia in Saudi Arabia had low frequency of P/LP mutations in cancer-related genes despite the high rate of consanguinity. Larger studies using whole-genome sequencing are needed to further explore the heritability of childhood leukemia.

Outcome of patients with Fanconi anemia developing myelodysplasia and acute leukemia who received allogeneic hematopoietic stem cell transplantation: A retrospective analysis on behalf of EBMT group

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is curative for bone marrow failure in patients with Fanconi anemia (FA), but the presence of a malignant transformation is associated with a poor prognosis and the management of these patients is still challenging. We analyzed outcome of 74 FA patients with a diagnosis of myelodysplastic syndrome (n = 35), acute leukemia (n = 35) or with cytogenetic abnormalities (n = 4), who underwent allo-HSCT from 1999 to 2016 in EBMT network. Type of diagnosis, pre-HSCT cytoreductive therapies and related toxicities, disease status pre-HSCT, donor type, and conditioning regimen were considered as main variables potentially influencing outcome. The 5-year OS and EFS were 42% (30-53%) and 39% (27-51%), respectively. Patients transplanted in CR showed better OS compared with those transplanted in presence of an active malignant disease (OS:71%[48-95] vs 37% [24-50],P = .04), while none of the other variables considered had an impact. Twenty-two patients received pre-HSCT cytoreduction and 9/22 showed a grade 3-4 toxicity, without any lethal event or negative influence on survival after HSCT(OS:toxicity pre-HSCT 48% [20-75%] vs no-toxicity 51% [25-78%],P = .98). The cumulative incidence of day-100 grade II-IV a-GvHD and of 5-year c-GvHD were 38% (26-50%) and 40% (28-52%). Non-relapse-related mortality and incidence of relapse at 5-years were 40% (29-52%) and 21% (11-30%) respectively, without any significant impact of the tested variables. Causes of death were transplant-related events in most patients (34 out of the 42 deaths, 81%). This analysis confirms the poor outcome of transformed FA patients and identifies the importance of achieving CR pre-HSCT, suggesting that, in a newly diagnosed transformed FA patient, a cytoreductive approach pre-HSCT should be considered if a donor have been secured.

Impact of autologous blood transfusion after bone marrow harvest on unrelated donor's health and outcome: a CIBMTR analysis

Pre-harvest autologous blood collection from bone marrow (BM) donors is performed to meet potential post-operative transfusion needs. This study examines the impact of autologous blood transfusion on BM donor's health and safety. The study included first-time unrelated BM donors from the United States whose BM harvest was facilitated by the National Marrow Donor Program (NMDP) centers between 2006 and 2017. Examination of 7024 BM donors revealed that 60% received at least one unit of autologous blood. The donors who received autologous blood were older, had lower hemoglobin pre-harvest, underwent longer duration of anesthesia, and higher volume BM harvest. Only donors who underwent high-volume BM harvest, defined as a BM harvest volume >27% of donor's blood volume, benefited from autologous transfusion. After a high-volume BM harvest, autologous blood transfusion was shown to decrease grade 2 to 4 collection-associated toxicities within 48 h of BM donation (p = 0.010) and shorten the time to donor-reported "complete" recovery from donation-associated symptoms (p < 0.001). Therefore, autologous transfusion could be avoided as support of marrow donation in the majority of unrelated BM donors and should be limited to cases where the planned BM harvest volume is expected to exceed 27% of donor's blood volume.

Outcome of hematopoietic stem cell transplantation (HCT) from HLA-matched related donor for Fanconi anemia (FA) in adolescents and adults: a retrospective study by Eastern Mediterranean Blood and Marrow Transplantation Group (EMBMT)

Hematopoietic Stem Cell Transplantation (HSCT) is the only potentially curative treatment option for the hematologic complications that occur in patients with Fanconi anemia (FA). In this study, we present a retrospective multicenter analysis from the Eastern Mediterranean Blood and Marrow Transplantation Group (EMBMT) of matched related donor HSCT for FA in adolescents and adults transplanted between 1988 and 2015. Forty-five patients received HSCT with a median age at transplant of 18 years, the interquartile range (IQR) (15-23.5); 25 (55.6%) patients were females and 20 (44.4%) were males. Conditioning regimen was fludarabine-based in 29 (64.4%) patients, irradiation-based in five (11.1%) patients, and the remaining patients received other combinations. Indication for HSCT was bone marrow failure in 39 (86.7%) and myelodysplastic syndrome in six (13.3%) patients. Stem cell source was bone marrow in 22 (48.9%), peripheral blood in 20 (44.4%), umbilical cord blood in one (2.2%), and combination of bone marrow and cord blood in two (4.4%) patients. Twenty-seven (60%) patients engrafted and five (11.1%) had primary engraftment failure. The median time to neutrophil engraftment was 14 days (range 10-21 days); median time for platelet engraftment was 17 days (10-33 days). The probability of developing grade II-IV acute GVHD for all patients was 7.0% and chronic GVHD 36.6%. No new malignancies were reported. The OS probability was 53.6% (95% CI, 38.3-68.9%) with a median follow-up of 13 months (95% CI, 1-240). Our HLA-matched related HSCT results in AYA patients with FA compare favorably with other reported international registry data.

Incidence, clinical distribution, and patient characteristics of childhood cancer in Saudi Arabia: A population-based analysis

PURPOSE

Information regarding the incidence and patterns of childhood malignancies is disproportionately overrepresented by high-income countries, representing mainly the Caucasian population. There is a need to evaluate and disseminate information for other ethnicities, particularly from the Middle East.

METHODS

Data from the National Cancer Registry, Saudi Arabia (SA-NCR), for pediatric patients (age 0-14 years) diagnosed between 2005 and 2009 and for similar patients at our institution during the same period were analyzed. Population numbers reported in the 2007 national census were used to calculate the annual incidence of childhood cancer.

RESULTS

Data from SA-NCR on 3885 patients were included in this analysis. The median age was 5.58 years, and 57.3% were males. The annual age-specific cancer incidence rate (ASR) for children in SA is 99.83 per million population; ASR per million for lymphoid leukemia is 25.75, 12.05 for brain tumors, and 9.82 for Hodgkin lymphoma. Of all childhood cancers in SA, 35% were treated at our institution. The five-year overall survival for these 1350 patients is 74.6% (median follow-up 7.52 years [95% confidence interval: 7.36-7.68]). Significant differences in the distribution of childhood malignancy subtypes were evident compared with other countries.

CONCLUSION

We have reported differences in the cancer ASR and cancer subtype distribution for children in SA as compared with the worldwide incidence and with other populations. This paper provides a comprehensive epidemiological overview of childhood cancer in SA, which could be extrapolated to other regional Arab populations.

Successful hematopoietic cell transplantation in Fanconi anemia patients with renal impairment using ultra-reduced doses of cyclophosphamide and fludarabine

Hematopoietic cell transplantation (HCT) remains until now the only curative modality for hematological manifestations in patients with Fanconi anemia (FA). The doses of alkylating agents used in the conditioning of this patient population before HCT are usually significantly decreased due to the genomic instability of the FA cells. FA patients with renal impairment represent a dilemma because of the need to further modify the conditioning regimen according to the degree of renal impairment to avoid additional toxicity. At our institution, we successfully transplanted three FA patients using an ultra-modified regimen.

Prevalence of hereditary cancer susceptibility syndromes in children with cancer in a highly consanguineous population

BACKGROUND & AIM

Hereditary cancer susceptibility syndromes (HCSS) are reported in up to one-third of children with cancer. Diagnosis of HCSS is crucial for implementation of surveillance protocols. We identified children who fulfilled criteria for HCSS in Saudi Arabia using the American College of Medical Genetics and Genomics (ACMG) guidelines, addressing the utility of these guidelines in a highly consanguineous population.

METHODS

This multi-center cross-sectional study recruited 1858 children with cancer between January 2011 and December 2014. HCSS criteria were based on the ACMG guidelines.

RESULTS

Seven hundred and four (40.4%) out of 1742 eligible patients fulfilled criteria for HCSS. Consanguinity was reported in 629 (38%) patients, with 50 (2.9%) first-degree, 535 (30.7%) second-degree, and 272 (15.6%) third-degree relatives affected with cancer. Two hundred and eighty eight (17.4%) leukemia and 87 (5.3%) brain tumour patients fulfilled HCSS criteria, with parental consanguinity being the most frequent criterion in both (leukemia 85.4%, brain tumors 83.9%). However, leukemia was less frequent in patients of consanguineous parents (p = 0.023).

CONCLUSION

Four out of 10 children with cancer fulfilled criteria for HCSS, most often due to consanguinity. This higher than expected prevalence suggests the need to validate consanguinity as a criterion for HCSS in highly consanguineous populations.

Low Body Mass Index Is Associated with Increased Risk of Acute GVHD after Umbilical Cord Blood Transplantation in Children and Young Adults with Acute Leukemia: A Study on Behalf of Eurocord and the EBMT Pediatric Disease Working Party

Body mass index (BMI) may influence outcomes after allogeneic hematopoietic stem cell transplantation (HSCT). However, the impact of BMI on survival in children undergoing HSCT is not well defined, with conflicting results being reported on this issue. We analyzed 855 patients age 2 to 20 years with diagnosis of acute leukemia who underwent umbilical cord blood transplantation (UCBT) from 1990 to 2015. Patients were classified according to BMI as normal (fifth to 85th percentile), underweight (less than fifth percentile), overweight (85th to 95th percentile), and obese (>95th percentile) using growth charts for age and sex. All patients received single-unit UCBT after a myeloablative conditioning regimen. Diagnosis was acute lymphoblastic leukemia in 68% of the patients. Sixty-one percent of patients (n = 523) were in the normal BMI category, 11% (n = 96) were underweight, 16% (n = 137) overweight, and 12% (n = 99) obese. The cumulative incidence of grade II to IV acute graft-versus-host disease (aGVHD) was 35% (32% to 38%). According to pretransplantation BMI, aGVHD was 46% (33% to 59%) for underweight, 34% (31% to 42%) for normal, 36% (18% to 38%) for overweight, and 27% (15% to 37%) for obese (P = .04). In multivariate analysis, a BMI less than the fifth percentile was associated with higher incidence of acute grade II to IV GVHD compared with normal-BMI patients (hazard ratio,  1.61; 95% confidence interval, 1.15 to 2.26; P = .006). Our results show that being underweight at the time of transplantation is associated with an increased risk of aGVHD, highlighting the importance of nutritional status before UCBT.

Influence of Age on Acute and Chronic GVHD in Children Undergoing HLA-Identical Sibling Bone Marrow Transplantation for Acute Leukemia: Implications for Prophylaxis

Relapse remains the major cause of mortality after hematopoietic cell transplantation (HCT) for pediatric acute leukemia. Previous research has suggested that reducing the intensity of calcineurin inhibitor-based graft-versus-host disease (GVHD) prophylaxis may be an effective strategy for abrogating the risk of relapse in pediatric patients undergoing matched sibling donor (MSD) HCT. We reasoned that the benefits of this strategy could be maximized by selectively applying it to those patients least likely to develop GVHD. We conducted a study of risk factors for GVHD, to risk-stratify patients based on age. Patients age <18 years with leukemia who received myeloablative, T cell-replete MSD bone marrow transplantation and calcineurin inhibitor-based GVHD prophylaxis between 2000 and 2013 and were entered into the Center for International Blood and Marrow Transplant Research registry were included. The cumulative incidence of grade II-IV acute GVHD (aGVHD) was 19%, that of grade II-IV aGVHD 7%, and that of chronic GVHD (cGVHD) was 16%. Compared with age 13 to 18 years, age 2 to 12 years was associated with a lower risk of grade II-IV aGVHD (hazard ratio [HR], .42; 95% confidence interval [CI], .26 to .70; P = .0008), grade II-IV aGVHD (HR, .24; 95% CI, .10 to .56; P = .001), and cGVHD (HR, .32; 95% CI, .19 to .54; P < .001). Compared with 2000-2004, the risk of grade II-IV aGVHD was lower in children undergoing transplantation in 2005-2008 (HR, .36; 95% CI, .20 to .65; P = .0007) and in 2009-2013 (HR, .24; 95% CI. .11 to .53; P = .0004). Similarly, the risk of grade III-IV aGVHD was lower in children undergoing transplantation in 2005-2008 (HR, .23; 95% CI, .08 to .65; P = .0056) and 2009-2013 (HR, .16; 95% CI, .04 to .67; P = .0126) compared with those doing so in 2000-2004. We conclude that aGVHD rates have decreased significantly over time, and that children age 2 to 12 years are at very low risk for aGVHD and cGVHD. These results should be validated in an independent analysis, because these patients with high-risk malignancies may be good candidates for trials of reduced GVHD prophylaxis.

Factors Associated with Long-Term Risk of Relapse after Unrelated Cord Blood Transplantation in Children with Acute Lymphoblastic Leukemia in Remission

For pediatric patients with acute lymphoblastic leukemia (ALL), relapse is an important cause of treatment failure after unrelated cord blood transplant (UCBT). Compared with other donor sources, relapse is similar or even reduced after UCBT despite less graft-versus-host disease (GVHD). We performed a retrospective analysis to identify risk factors associated with the 5-year cumulative incidence of relapse after UCBT. In this retrospective, registry-based study, we examined the outcomes of 640 children (<18 years) with ALL in first complete remission (CR1; n = 257, 40%) or second complete remission (CR2; n = 383, 60%) who received myeloablative conditioning followed by a single-unit UCBT from 2000 to 2012. Most received antithymocyte globulin (88%) or total body irradiation (TBI; 69%), and cord blood grafts were primarily mismatched at 1 (50%) or 2+ (34%) HLA loci. Considering patients in CR1, the rates of 5-year overall survival (OS), leukemia-free survival (LFS), and relapse were 59%, 52%, and 23%, respectively. In multivariate analysis (MVA), acute GVHD (grades II to IV) and TBI protected against relapse. In patients in CR2, rates of 5-year OS, LFS, and the cumulative incidence of relapse were 46%, 44%, and 28%, respectively. In MVA, longer duration from diagnosis to UCBT (≥30 months) and TBI were associated with decreased relapse risk. Importantly, receiving a fully HLA matched graft was a strong risk factor for increased relapse in MVA. An exploratory analysis of all 640 patients supported the important association between the presence of acute GVHD and less relapse but also demonstrated an increased risk of nonrelapse mortality. In conclusion, the impact of GVHD as a graft-versus-leukemia marker is evident in pediatric ALL after UCBT. Strategies that promote graft-versus-leukemia while harnessing GVHD should be further investigated.

A Multicenter Retrospective Analysis Stressing the Importance of Long-Term Follow-Up after Hematopoietic Cell Transplantation for β-Thalassemia

Allogeneic hematopoietic cell transplantation (HCT) is curative in patients with β-thalassemia major. However, most reports on HCT outcomes lack long-term follow-up data with the exception of single-center reports. An international multicenter retrospective data collection and analysis was conducted in 176 β-thalassemia patients who were 1 year or beyond after first HCT to evaluate follow-up methods and outcomes at 7 centers. Median age at HCT was 5.5 years (range, .6 to 18.5), and median follow-up was 7 years (range, 1 to 20). HCT was predominantly from HLA-matched related donors (91%) with bone marrow as stem cell source (91%) and myeloablative conditioning regimens (88%). Late mortality or persistent chronic graft-versus-host disease (GVHD) was rare (<2%). Graft rejection was reported in 23% (24% of these occurred beyond 1 year) post-HCT. Of 119 patients with donor chimerism results available for ≥4 years post-HCT, 50% had >95%, 22% had 50% to 95%, 7% had 20% to 50% and 25 (21%) had <20% donor chimerism. Organ dysfunction was identified in 10% pre-HCT and in 20% post-HCT even without complete clinical details on all patients. Hypogonadism and elevated creatinine for age were most commonly reported and significantly higher in recipients ≥ 7 years at the time of HCT (P = .007) and in those with pre-existing morbidity before HCT (P = .02). Outcomes were unaffected by pre-HCT ferritin or GVHD. Mean z scores for height and weight were low at baseline and remained low post-HCT (79%), confirming that growth impairment from disease lacked recovery post-HCT during this follow-up period. HCT for β-thalassemia has a high rate of cure and low mortality, especially in the young and from HLA-matched related donors. Half of the number of recipients live with mixed chimerism that requires continued follow-up because of a risk of late graft rejection (14%). Organ function after HCT when <7 years of age was generally preserved. Hypogonadism, renal dysfunction, and growth impairment that failed to correct were late complications identified most frequently in older transplant recipients. Systematic follow-up of individual organs such as lung and heart were inadequate but important. These data support the development of simple measures of uniformly tracking long-term HCT outcomes and organ functions in children and adolescents who undergo HCT for thalassemia, allowing for systematic identification and implementation of standardized surveillance strategies and interventions.

Effect of antithymocyte globulin source on outcomes of bone marrow transplantation for severe aplastic anemia

For treatment of severe aplastic anemia, immunosuppressive therapy with horse antithymocyte globulin results in superior response and survival compared with rabbit antithymocyte globulin. This relative benefit may be different in the setting of transplantation as rabbit antithymocyte globulin results in more profound immunosuppression. We analyzed 833 severe aplastic anemia transplants between 2008 and 2013 using human leukocyte antigen (HLA)-matched siblings (n=546) or unrelated donors (n=287) who received antithymocyte globulin as part of their conditioning regimen and bone marrow graft. There were no differences in hematopoietic recovery by type of antithymocyte globulin. Among recipients of HLA-matched sibling transplants, day 100 incidence of acute (17% versus 6%, P<0.001) and chronic (20% versus 9%, P<0.001) graft-versus-host disease were higher with horse compared to rabbit antithymocyte globulin. There were no differences in 3-year overall survival, 87% and 92%, P=0.76, respectively. Among recipients of unrelated donor transplants, acute graft-versus-host disease was also higher with horse compared to rabbit antithymocyte globulin (42% versus 23%, P<0.001) but not chronic graft-versus-host disease (38% versus 32%, P=0.35). Survival was lower with horse antithymocyte globulin after unrelated donor transplantation, 75% versus 83%, P=0.02. These data support the use of rabbit antithymocyte globulin for bone marrow transplant conditioning for severe aplastic anemia.

Sickle cell disease: an international survey of results of HLA-identical sibling hematopoietic stem cell transplantation

Despite advances in supportive therapy to prevent complications of sickle cell disease (SCD), access to care is not universal. Hematopoietic cell transplantation is, to date, the only curative therapy for SCD, but its application is limited by availability of a suitable HLA-matched donor and lack of awareness of the benefits of transplant. Included in this study are 1000 recipients of HLA-identical sibling transplants performed between 1986 and 2013 and reported to the European Society for Blood and Marrow Transplantation, Eurocord, and the Center for International Blood and Marrow Transplant Research. The primary endpoint was event-free survival, defined as being alive without graft failure; risk factors were studied using a Cox regression models. The median age at transplantation was 9 years, and the median follow-up was longer than 5 years. Most patients received a myeloablative conditioning regimen (n = 873; 87%); the remainder received reduced-intensity conditioning regimens (n = 125; 13%). Bone marrow was the predominant stem cell source (n = 839; 84%); peripheral blood and cord blood progenitors were used in 73 (7%) and 88 (9%) patients, respectively. The 5-year event-free survival and overall survival were 91.4% (95% confidence interval, 89.6%-93.3%) and 92.9% (95% confidence interval, 91.1%-94.6%), respectively. Event-free survival was lower with increasing age at transplantation (hazard ratio [HR], 1.09; P < .001) and higher for transplantations performed after 2006 (HR, 0.95; P = .013). Twenty-three patients experienced graft failure, and 70 patients (7%) died, with the most common cause of death being infection. The excellent outcome of a cohort transplanted over the course of 3 decades confirms the role of HLA-identical sibling transplantation for children and adults with SCD.

Improved survival after acute graft-versus-host disease diagnosis in the modern era

A cute graft-versus-host disease remains a major threat to a successful outcome after allogeneic hematopoietic cell transplantation. While improvements in treatment and supportive care have occurred, it is unknown whether these advances have resulted in improved outcome specifically among those diagnosed with acute graft-versus-host disease. We examined outcome following diagnosis of grade II-IV acute graft-versus-host disease according to time period, and explored effects according to original graft-versus-host disease prophylaxis regimen and maximum overall grade of acute graft-versus-host disease. Between 1999 and 2012, 2,905 patients with acute myeloid leukemia (56%), acute lymphoblastic leukemia (30%) or myelodysplastic syndromes (14%) received a sibling (24%) or unrelated donor (76%) blood (66%) or marrow (34%) transplant and developed grade II-IV acute graft-versus-host disease (n=497 for 1999–2001, n=962 for 2002–2005, n=1,446 for 2006–2010). The median (range) follow-up was 144 (4–174), 97 (4–147) and 60 (8–99) months for 1999–2001, 2002–2005, and 2006–2010, respectively. Among the cohort with grade II-IV acute graft-versus-host disease, there was a decrease in the proportion of grade III-IV disease over time with 56%, 47%, and 37% for 1999–2001, 2002–2005, and 2006–2012, respectively (P<0.001). Considering the total study population, univariate analysis demonstrated significant improvements in overall survival and treatment-related mortality over time, and deaths from organ failure and infection declined. On multivariate analysis, significant improvements in overall survival (P=0.003) and treatment-related mortality (P=0.008) were only noted among those originally treated with tacrolimus-based graft-versus-host disease prophylaxis, and these effects were most apparent among those with overall grade II acute graft-versus-host disease. In conclusion, survival has improved over time for tacrolimus-treated transplant recipients with acute graft-versus-host disease.

Factors Determining the Outcome of Hematopoietic Stem Cell Transplantation in Patients With Acute Lymphoblastic Leukemia at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia

Medical records of 82 patients with acute lymphoblastic leukemia (ALL) who underwent hematopoietic cell transplantation (HCT) at our institution from 2005 to 2011 were reviewed. Forty-five patients were male (54.8%). The median age at HCT was 7.46 years (range, 0.98 to 14.31 y), the median time to HCT after diagnosis was 12.56 months. Ten patients were below the age of 1 year (12%). All patients were in complete remission at the time of HCT. In 83 transplants, 64 patients received HCT from human leukocyte antigen-identical-related donors and 19 from other donors. Stem cell source was bone marrow in 65 (78%) and cord blood in 18 (22%). Five-year overall survival was 58.8% and event-free survival was 54.3%. The cumulative incidence of acute graft versus host disease was 4.8%±2.3% and of chronic graft versus host disease was 8.9%±3.2%. The median time to absolute neutrophil count and platelet recovery was 17 days (range, 12 to 43 d) and 28 days (range, 15 to 98 d), respectively. One patient acquired CMV infection after transplant. No one developed venoocclusive disease, hemorrhagic cystitis, or other complication. Patient's age at diagnosis, sex, donor's human leukocyte antigen status and sex, source of transplant and complete remission status at HCT did not affect overall survival and event-free survival. Our results show a favorable outcome to HCT for acute lymphoblastic leukemia patients comparable to published data, and no single factor was associated with superior outcome.

First report of pediatric hematopoietic stem cell transplantation activities in the eastern mediterranean region from 1984 to 2011: on behalf of the pediatric cancer working committee of the eastern mediterranean blood and marrow transplantation group

To describe the hematopoietic stem cell transplantation (HSCT) activities for children in the Eastern Mediterranean (EM) region, data on transplants performed for children less than 18 years of age between 1984 and 2011 in eight EM countries (Egypt, Iran, Jordan, Lebanon, Oman, Pakistan, Saudi Arabia and Tunisia) were collected. A total of 5187 transplants were performed, of which 4513 (87%) were allogeneic and 674 (13%) were autologous. Overall, the indications for transplantation were malignant diseases in 1736 (38.5%) and non-malignant in 2777 (61.5%) patients. A myeloablative conditioning regimen was used in 88% of the allografts. Bone marrow (BM) was the most frequent source of stem cells (56.2%), although an increasing use of PBSC was observed in the last decade. The stem cell source of autologous HSCT has shifted over time from BM to PBSC, and 80.9% of autologous HSCTs were from PBSCs. The donors for allogeneic transplants were matched-related in 94.5% of the cases, and unrelated transplants, mainly cord blood (99%) in 239 (5.5%) cases. This is the first report to describe the pediatric HSCT activities in EM countries. Non-malignant disorders are the main indication for allogeneic transplantation. Frequency of alternate donor transplantation is low.

Hematopoietic stem cell transplant for hyper-IgM syndrome due to CD40L defects: A single-center experience

HIGMI is a disease with a high risk for morbidity and mortality. HSCT has been shown to be a curative option. This study retrospectively reviewed and analyzed data from five patients who received HSCT at King Faisal Specialist Hospital & Research Centre (KFSH&RC) in Riyadh, Saudi Arabia, between 2005 and 2013. Five patients with HIGMI syndrome underwent HSCT at a median age of 41 months (range, 9-72 months). The median time from diagnosis to transplantation was 30 months (range, 5-58 months). For all five patients, the donors were HLA-identical siblings. In three patients, the conditioning regimen was composed of BU and CY. Fludarabine and melphalan with either ATG or alemtuzumab was used in two patients. For GVHD prophylaxis, cyclosporine was used in two patients, and the combination of cyclosporine and MTX was used in three patients. The survival rate was 100%, with a median follow-up of 69 months (range, 13-100 months). All patients engrafted. Two patients developed acute GVHD. Four patients showed complete immune recovery with positive CD40L expression in activated T cells and discontinued IVIG replacement. HSCT in early stage from an HLA-matched sibling donor is potentially effective at curing the disease.

Transplant Outcomes for Children with T Cell Acute Lymphoblastic Leukemia in Second Remission: A Report from the Center for International Blood and Marrow Transplant Research

Survival for children with relapsed T cell acute lymphoblastic leukemia (T-ALL) is poor when treated with chemotherapy alone, and outcomes after allogeneic hematopoietic cell transplantation (HCT) is not well described. Two hundred twenty-nine children with T-ALL in second complete remission (CR2) received an HCT after myeloablative conditioning between 2000 and 2011 and were reported to the Center for International Blood and Marrow Transplant Research. Median age was 10 years (range, 2 to 18). Donor source was umbilical cord blood (26%), matched sibling bone marrow (38%), or unrelated bone marrow/peripheral blood (36%). Acute (grades II to IV) and chronic graft-versus-host disease occurred in, respectively, 35% (95% confidence interval [CI], 27% to 45%) and 26% (95% CI, 20% to 33%) of patients. Transplant-related mortality at day 100 and 3-year relapse rates were 13% (95% CI, 9% to 18%) and 30% (95% CI, 24% to 37%), respectively. Three-year overall survival and disease-free survival rates were 48% (95% CI, 41% to 55%) and 46% (95% CI, 39% to 52%), respectively. In multivariate analysis, patients with bone marrow relapse, with or without concurrent extramedullary relapse before HCT, were most likely to relapse (hazard ratio, 3.94; P = .005) as compared with isolated extramedullary disease. In conclusion, HCT for pediatric T-ALL in CR2 demonstrates reasonable and durable outcomes, and consideration for HCT is warranted.