Purpose

Lymphocyte subset recovery is an important factor that determines the success of hematopoietic stem cell transplantation (HSCT). Temporal differences in the recovery of lymphocyte subsets and the factors influencing this recovery are important variables that affect a patient's post-transplant immune reconstitution, and therefore require investigation.

Methods

The time taken to achieve lymphocyte subset recovery and the factors influencing this recovery were investigated in 59 children who had undergone HSCT at the Department of Pediatrics, The Catholic University of Korea Seoul St. Mary's Hospital, and who had an uneventful follow-up period of at least 1 year. Analyses were carried out at 3 and 12 months post-transplant. An additional study was performed 1 month post-transplant to evaluate natural killer (NK) cell recovery. The impact of pre- and post-transplant variables, including diagnosis of Epstein-Barr virus (EBV) DNAemia posttransplant, on lymphocyte recovery was evaluated.

Results

The lymphocyte subsets recovered in the following order: NK cells, cytotoxic T cells, B cells, and helper T cells. At 1 month post-transplant, acute graft-versus-host disease was found to contribute significantly to the delay of CD16+/56+ cell recovery. Younger patients showed delayed recovery of both CD3+/CD8+ and CD19+ cells. EBV DNAemia had a deleterious impact on the recovery of both CD3+ and CD3+/CD4+ lymphocytes at 1 year post-transplant.

Conclusion

In our pediatric allogeneic HSCT cohort, helper T cells were the last subset to recover. Younger age and EBV DNAemia had a negative impact on the post-transplant recovery of T cells and B cells.

Purpose

Acute appendicitis has been reported to be relatively rare in pediatric leukemia patients but there is no official data for this in Korea. And there is no consensus for its treatment in this population.

Materials and Methods

We conducted a retrospective study of 7 patients diagnosed with appendicitis among 1209 pediatric patients who were diagnosed with leukemia from 1996 to 2008 at a single institution in Korea.

Results

The median age at the time of the diagnosis of appendicitis was 12 years (range: 3-15 years), and 3 of the patients were male. The median absolute neutrophil count (ANC) at the time of diagnosis was 0.99×109/L (range: 0-3×109/L). The mean time from the onset of symptoms to the diagnosis was 4 days. All 7 leukemia patients with appendicitis underwent surgery and they demonstrated a survival of 100% without significant complications.

Conclusion

The incidence of appendicitis in pediatric leukemia patients was 0.57% in our study. Early diagnosis with abdominal ultrasound or computed tomography and early surgical resection in leukemic patient with acute appendicitis may be a safer and more effective treatment option. Even when perforation has already occurred and when the patient has an ANC of 0×109/L, surgical treatment may improve overall survival without incurring significant complications.

Background

Diamond Blackfan anemia (DBA), characterized by impaired red cell production, is a rare condition that is usually symptomatic in early infancy. The purpose of this study was to assess nationwide experiences of DBA encountered over a period of 20 years.

Methods

The medical records of 56 patients diagnosed with DBA were retrospectively reviewed from November 1984 to July 2010. Fifteen institutions, including 13 university hospitals, participated in this study.

Results

The male-to-female ratio of patients with DBA was 1.67:1. The median age of diagnosis was 4 months, and 74.1% were diagnosed before 1 year of age. From 2000 to 2009, annual incidence was 6.6 cases per million. Excluding growth retardation, 38.2% showed congenital defects: thumb deformities, ptosis, coarctation of aorta, ventricular septal defect, strabismus, etc. The mean hemoglobin concentration was 5.1±1.9 g/dL, mean corpuscular volume was 93.4±11.6 fL, and mean number of reticulocytes was 19,700/mm3. The mean cellularity of bone marrow was 75%, with myeloid:erythroid ratio of 20.4:1. After remission, 48.9% of patients did not need further steroids. Five patients with DBA who received hematopoietic transplantation have survived. Cancer developed in 2 cases (3.6%).

Conclusion

The incidence of DBA is similar to data already published, but our study had a male predilection. Although all patients responded to initial treatment with steroids, about half needed further steroids after remission. It is necessary to collect further data, including information regarding management pathways, from nationwide DBA registries, along with data on molecular analyses.

Purpose

Improved survival of patients with childhood acute lymphoblastic leukemia (ALL) has drawn attention to the potential for late consequences of previous treatments among survivors, including metabolic syndrome. In this study, we evaluated changes in 3 parameters, namely, random blood glucose, body mass index (BMI), and Z score for BMI (Z-BMI), in children with ALL during chemotherapy and after completion of treatment.

Methods

Patients newly diagnosed with ALL from January, 2005 to December, 2008 at Saint Mary's Hospital, The Catholic University of Korea, who completed treatment with chemotherapy only were included (n=107). Random glucose, BMI, and Z-BMI were recorded at 5 intervals: at diagnosis, before maintenance treatment, at completion of maintenance treatment, and 6 and 12 months after completion of maintenance treatment. Similar analyses were conducted on 2 subcohorts based on ALL risk groups.

Results

For random glucose, a paired comparison showed significantly lower levels at 12 months post-treatment compared to those at initial diagnosis (P<0.001) and before maintenance (P<0.001). The Z-BMI score was significantly higher before maintenance than at diagnosis (P<0.001), but decreased significantly at the end of treatment (P<0.001) and remained low at 6 months (P<0.001) and 12 months (P<0.001) post-treatment. Similar results were obtained upon analysis of risk group-based subcohorts.

Conclusion

For a cohort of ALL patients treated without allogeneic transplantation or cranial irradiation, decrease in random glucose and Z-BMI after completion of chemotherapy does not indicate future glucose intolerance or obesity.

Purpose

The survival rate for childhood acute lymphoblastic leukemia (ALL) has improved significantly. However, overall prognosis for the 20 to 25% of patients who relapse is poor, and allogeneic hematopoietic stem cell transplantation (HSCT) offers the best chance for cure. In this study, we identified significant prognostic variables by analyzing the outcomes of allogeneic HSCT in ALL patients in second complete remission (CR).

Methods

Fifty-three ALL patients (42 men, 79%) who received HSCT in second CR from August 1991 to February 2009 were included (26 sibling donor HSCTs, 49%; 42 bone marrow transplantations, 79%). Study endpoints included cumulative incidence of acute and chronic graft-versus-host disease (GVHD), relapse, 1-year transplant-related mortality (TRM), disease-free survival (DFS), and overall survival (OS).

Results

Cumulative incidences of acute GVHD (grade 2 or above) and chronic GVHD were 45.3% and 28.5%, respectively. The estimated 5-year DFS and OS for the cohort was 45.2±6.8% and 48.3±7%, respectively. Only donor type, i.e., sibling versus unrelated, showed significant correlation with DFS in multivariate analysis (P=0.010). The rates of relapse and 1 year TRM were 28.9±6.4% and 26.4±6.1%, respectively, and unrelated donor HSCT (P=0.002) and HLA mismatch (P=0.022) were significantly correlated with increased TRM in univariate analysis.

Conclusion

In this single institution study spanning more than 17 years, sibling donor HSCT was the only factor predicting a favorable result in multivariate analysis, possibly due to increased TRM resulting from unrelated donor HSCT.

The aim of this study was to investigate the diphtheria-tetanus-pertussis antibody titers after antineoplastic treatment and to suggest an appropriate vaccination approach for pediatric hemato-oncologic patients. A total of 146 children with either malignancy in remission after cessation of therapy or bone marrow failure were recruited. All children had received routine immunization including diphtheria-tetanus-acellular pertussis vaccination before diagnosis of cancer. The serologic immunity to diphtheria, tetanus and pertussis was classified as: completely protective, partially protective, or non-protective. Non-protective serum antibody titer for diphtheria, tetanus and pertussis was detected in 6.2%, 11.6%, and 62.3% of patients, respectively, and partial protective serum antibody titer for diphtheria, tetanus and pertussis was seen in 37%, 28.1%, and 8.9% of patients. There was no significant correlation between the severity of immune defect and age, gender or underlying disease. Revaccination after antineoplastic therapy showed significantly higher levels of antibody for each vaccine antigen. Our data indicates that a large proportion of children lacked protective serum concentrations of antibodies against diphtheria, tetanus, and pertussis. This suggests that reimmunization of these patients is necessary after completion of antineoplastic treatment. Also, prospective studies should be undertaken with the aim of devising a common strategy of revaccination.

Purpose

In this study, we analyzed a cohort of children with chronic graft-versus-host disease (GvHD) according to the NIH consensus classification (NCC) in order to observe whether global assessment at diagnosis correlates with GvHD-specific endpoints. We then studied the clinical course of these patients, specifically with regards to episodes of GvHD exacerbation requiring treatment escalation.

Materials and Methods

Recipients of either allogeneic bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT) from January 2006 to August 2008 at the Department of Pediatrics, The Catholic University of Korea were evaluated for chronic GvHD, which was diagnosed according to the NCC. The course of chronic GvHD in these patients was then followed.

Results

Of 59 evaluable patients, 23 developed chronic GvHD for a cumulative incidence of 39.3%. Upon multivariate analysis, previous acute GvHD (≥grade II) had a significant impact on chronic GvHD incidence. With a median duration of systemic treatment for chronic GvHD of 501 days, no significant relationship was found between initial global severity of chronic GvHD and either duration of immunosuppressive treatment or final clinical response to treatment. Fifteen patients (65%) experienced at least one episode of chronic GvHD exacerbation during the period of follow-up, with a median of four exacerbations in the subgroup of patients who experienced such events. Lung GvHD resulted in the highest number of exacerbations per diagnosed patient, followed by oral GvHD.

Conclusion

Analysis of this small cohort indicates that global assessment as proposed by the NCC may have limited correlations with GvHD-specific endpoints, possibly due to the favorable response of children to treatment.

Background

Combination treatment with all-trans-retinoic acid (ATRA) and anthracycline-based chemotherapy has led to major advances in the treatment of acute promyelocytic leukemia (APL).

Methods

In this study, we reviewed the outcome of pediatric APL patients treated using a modified AIDA protocol at our institution.

Results

Between May 1999 and December 2007, 23 patients were diagnosed with APL at the Department of Pediatrics, Saint Mary's Hospital, The Catholic University of Korea. Eleven patients were male (48%) (median age at diagnosis, 11 (range, 2-14) years). The treatment protocol consisted of remission induction (achieved by coadministration of ATRA and idarubicin), 3 courses of consolidation treatment, and 2 years of maintenance treatment during which ATRA was also administered. Three patients died early during remission induction due to CNS hemorrhage. The remaining 20 patients achieved complete remission (CR), with an overall CR rate of 87%. Two patients relapsed and died, and another patient died of pneumonia unrelated to APL. Four patients (17%) were diagnosed with ATRA syndrome, and all patients showed resolution of symptoms. The event-free survival (EFS) and overall survival (OS) of the cohort were 78.3±8.6% and 76.3±9.5%, respectively. Initial WBC count at diagnosis was the only significant prognostic factor for the rate of CR (P=0.039) and OS (P=0.039).

Conclusion

A modified AIDA protocol for the treatment of childhood APL leads to improved EFS and OS, with limited ATRA syndrome-associated toxicity. Active monitoring and treatment of patients with high initial WBC counts may help in reducing mortality.

The efficacy of tandem high-dose chemotherapy and autologous stem cell rescue (HDCT/ASCR) was investigated in patients with high-risk neuroblastoma. Patients over 1 yr of age who were newly diagnosed with stage 4 neuroblastoma from January 2000 to December 2005 were enrolled in The Korean Society of Pediatric Hematology-Oncology registry. All patients who were assigned to receive HDCT/ASCR at diagnosis were retrospectively analyzed to investigate the efficacy of single or tandem HDCT/ASCR. Seventy and 71 patients were assigned to receive single or tandem HDCT/ASCR at diagnosis. Fifty-seven and 59 patients in the single or tandem HDCT group underwent single or tandem HDCT/ASCR as scheduled. Twenty-four and 38 patients in the single or tandem HDCT group remained event free with a median follow-up of 56 (24-88) months. When the survival rate was analyzed according to intent-to-treat at diagnosis, the probability of the 5-yr event-free survival±95% confidence intervals was higher in the tandem HDCT group than in the single HDCT group (51.2±12.4% vs. 31.3±11.5%, P=0.030). The results of the present study demonstrate that the tandem HDCT/ASCR strategy is significantly better than the single HDCT/ASCR strategy for improved survival in the treatment of high-risk neuroblastoma patients.

Background

Acute colonic pseudo-obstruction (ACPO) refers to dilatation of the colon and decreased bowel motility without evidence of mechanical obstruction. Neostigmine, an acetylcholinesterase inhibitor, has been used in patients in whom supportive therapy failed to resolve ACPO. Here, we report the results of administering neostigmine to treat ACPO in children with hematologic malignancies.

Methods

Between September 2005 and December 2009, 10 patients (8 male and 2 female) were diagnosed with ACPO at the Department of Pediatrics, Catholic University of Korea. Diagnosis of ACPO was based on typical clinical features as well as colonic dilatation found on abdominal CT imaging. Neostigmine was administered subcutaneously at a dosage of 0.01 mg/kg/dose (maximum 0.5 mg) twice daily for a maximum of 5 total doses. ACPO was determined to be responsive to neostigmine if the patient showed both stool passage and improvement of clinical symptoms.

Results

The study group included 8 acute lymphoblastic leukemia patients, 1 patient with malignant lymphoma, and 1 patient with juvenile myelomonocytic leukemia. The median age at ACPO diagnosis was 8.5 years (range, 3-14). Overall, 8 patients (80%) showed therapeutic response to neostigmine at a median of 29 hours after the initial administration (range, 1-70). Two patients (20%) showed side effects of grade 2 or above, but none complained of cardiovascular symptoms that required treatment.

Conclusion

In this study, ACPO was diagnosed most often in late-childhood ALL patients. Subcutaneous neostigmine can be used to effectively treat ACPO diagnosed in children with hematologic malignancies without major cardiovascular complications.

We investigated the outcome of idarubicin plus N4-behenoyl-1-β-D-arabinofuranosyl cytosine (BHAC)-based chemotherapy (BHAC group, n=149) compared to idarubicin plus cytarabine-based chemotherapy (cytarabine group, n=191) for childhood acute myeloid leukemia (AML). Between January 1996 and December 2005, 340 children with AML from 5 university hospitals in Korea received the BHAC-based or cytarabine-based chemotherapy, with or without hematopoietic stem cell transplantation. After induction therapy, 264 (77.6%) of 340 children achieved a complete remission (CR) and 43 (12%) achieved a partial remission (PR). The CR rate in the BHAC group was higher than in the cytarabine group (85.2% vs. 71.7%, P=0.004). However, the overall response rate (CR+PR) was not different between the two groups (93.3% vs. 87.9%, P=0.139). The 5-yr estimates of overall survival (OS) of children in the two groups were similar (54.9% for the BHAC group vs. 52.4% for the cytarabine group, P=0.281). Although the results were analyzed according to the treatment type and cytogenetic risk, the OS showed no significant difference between the BHAC group and the cytarabine group. In the present study, the clinical outcomes of the BHAC-based chemotherapy, consisting of BHAC, idarubicin, and 6-TG, are comparable to that of the cytarabine-based chemotherapy for childhood AML.

Long-term survivors of hematopoietic stem cell transplantation (HSCT) during childhood and adolescence are at risk of developing endocrine complications. The purpose of this study was to evaluate the long-term endocrine complications and their associated risk factors among such patients. We reviewed the data from 111 patients (59 males and 52 females) who underwent HSCT at the mean age of 8.3±4.1 yr. Thirty patients (27.0%) had growth impairment, and seven (21.2%) out of 33 patients who attained final height reached final height below 2 standard deviation (SD). The final height SD score of the patients conditioned with total body irradiation (TBI) was significantly lower than that of the patients conditioned without TBI (-1.18±1.14 vs. -0.19±0.78, P=0.011). Thirteen patients (11.7%) developed hypothyroidism (11 subclinical, 2 central) 3.8±1.8 (range 1.6-6.2) yr after HSCT. Nineteen (65.5%) out of 29 females had evidence of gonadal dysfunction, and 18 (64.3%) out of 28 males had evidence of gonadal dysfunction. The risk for gonadal dysfunction was significantly higher in females conditioned with busulfan/cyclophosphamide (P=0.003). These results suggest that the majority of patients treated with HSCT during childhood and adolescence have one or more endocrine complications. Therefore, multiple endocrine functions should be monitored periodically after HSCT until they reach adult age.

Autologous stem cell transplantation (ASCT) for the treatment of high-risk neuroblastoma (NBL) is an accepted method for restoring bone marrow depression after high dose chemotherapy. We retrospectively analyzed eighty eight cases of NBL that underwent ASCT following marrow ablative therapy at 12 transplant centers of the Korean Society of Pediatric Hematology-Oncology between January 1996 and September 2000. Seventy nine children were of stage IV NBL and 9 were of stage III with N-myc amplification. Various cytoreductive regimens were used. However, the main regimen was 'CEM' consisting of carboplatin, etoposide and melphalan, and this was used in 66 patients. Total body irradiation was also added in 36 patients for myeloablation. To reduce tumor cell contamination, stem cell infusions after CD34+ cell selection were performed in 16 patients. Post-transplantation therapies included the second transplantation in 18 patients, interleukin2 therapy in 45, 13-cis retinoic acid in 40, 131-meta-iodobenzylguanidine in 4, conventional chemotherapy in 11, and local radiotherapy in 8. Twenty two patients died, sixty six patients are surviving 1 to 46 months after ASCT (median followup duration, 14.5 months). Although the follow-up period was short and the number of patients small, we believe that ASCT might improve the survival rate in high-risk NBL.