Incidence, clinical features, and risk factors of idiopathic pneumonia syndrome following hematopoietic stem cell transplantation in children

BACKGROUND

Idiopathic pneumonia syndrome (IPS) is a severe complication that can occur after hematopoietic stem cell transplantation (HSCT) and is often associated with a fatal outcome despite intensive supportive care.

PROCEDURE

To assess the incidence and risk factors of IPS, we reviewed 251 consecutive patients (median age, 7.0 years) who received HSCT at the Department of Pediatrics, Nagoya University Hospital, between January 1990 and July 2009.

RESULTS

Twenty of 251 (cumulative incidence of IPS at 2 years after HSCT, 8.0%; 95% confidence interval (CI), 5.1-12.4%) patients developed IPS. The median duration from HSCT to diagnosis of IPS was 67 days (range, 12-486 days). Patients with IPS had significantly higher 5-year transplant-related mortality compared to patients without IPS (52% (95% CI, 19-77%) vs. 13% (95% CI, 5-25%), P < 0.001), and the probability of 5-year overall survival was significantly worse for patients with IPS (42% (95% CI, 25-64%) vs. 68% (95% CI, 59-76%), P = 0.01). By multivariate analysis, high risk in underlying disease (HR, 2.5; 95% CI, 1.0-6.7; P = 0.05) and a busulfan-containing regimen (HR, 3.5; 95% CI, 1.3-9.9; P < 0.01) were identified as the independent risk factors for developing IPS.

CONCLUSION

The prophylactic strategies for IPS in patients with these risk factors were warranted.

Application of high-dose rate (60)Co remote after-loading system for local recurrent neuroblastoma

The local control of neuroblastoma is a very important treatment consideration. We describe a patient who received high-dose rate 60Co remote after loading system treatment for local control of recurrent neuroblastoma and discuss the efficacy of high-dose rate 60Co remote after loading system treatment.

Total body irradiation and melphalan as a conditioning regimen for children with hematological malignancies undergoing transplantation with stem cells from HLA-identical related donors

Although some studies have reported that TBI and MEL offer an effective conditioning regimen for autologous SCT in acute leukemia, little has been reported regarding outcomes of allogeneic SCT. We retrospectively evaluated outcomes for 50 pediatric patients who underwent allo-SCT conditioned with intravenous MEL (180-210 mg/m(2) ) and fractionated TBI (12-13.2 Gy) from HLA-identical related donors. Nineteen patients were in CR1, 18 were in CR2, and 13 showed advanced-stage disease (≥ CR3). Patients had received allo-SCT from HLA-identical siblings (n = 45) or phenotypically HLA-identical family donors (n = 5). Median duration of follow-up for all disease-free patients was 61 months (range, 8.8-177 months). At the time of analysis, 12 patients had died. Eleven of those died of relapse, and one died of TRM. DFS rates for all patients, patients with AML (n = 12), and patients with lymphoid malignancy (n = 38) were 61.4% and 82.1%, respectively. DFS rates for CR1, CR2, and ≥CR3 cases were 89.2%, 88.1%, and 23.1%, respectively (p < 0.05). MEL/TBI for pediatric patients with hematological malignancies was associated with lower relapse rates and no increase in toxicity, resulting in better survival.

CD20-negative Epstein-Barr virus-associated post-transplant lymphoproliferative disease refractory to rituximab in a patient with severe aplastic anemia

Epstein-Barr virus-associated post-transplant lymphoproliferative disease (EBV-PTLD) is a life-threatening complication following allogeneic hematopoietic stem cell transplantation (HSCT). Monitoring of EBV DNA in high-risk patients with subsequent pre-emptive rituximab treatment is highly effective, and can prevent EBV-associated disease following HSCT. Here, we report a 10-year-old girl with aplastic anemia who developed CD20 negative EBV-PTLD after unrelated bone marrow transplantation that was refractory to rituximab treatment. Similar to other types of lymphoma, the absence of CD20 antigen is likely to be characteristic of rituximab-refractory EBV-PTLD.

Relapse of aplastic anemia in children after immunosuppressive therapy: a report from the Japan Childhood Aplastic Anemia Study Group

BACKGROUND

Although the therapeutic outcome of acquired aplastic anemia has improved markedly with the introduction of immunosuppressive therapy using antithymocyte globulin and cyclosporine, a significant proportion of patients subsequently relapse and require second-line therapy. However, detailed analyses of relapses in aplastic anemia children are limited.

DESIGN AND METHODS

We previously conducted two prospective multicenter trials of immunosuppressive therapy for children with aplastic anemia: AA-92 and AA-97, which began in 1992 and 1997, respectively. In this study, we assessed the relapse rate, risk factors for relapse, and the response to second-line treatment in children with aplastic anemia treated with antithymocyte globulin and cyclosporine.

RESULTS

From 1992 to 2007, we treated 441 children with aplastic anemia with standard immunosuppressive therapy. Among the 264 patients who responded to immunosuppressive therapy, 42 (15.9%) relapsed. The cumulative incidence of relapse was 11.9% at 10 years. Multivariate analysis revealed that relapse risk was significantly associated with an immunosuppressive therapy regimen using danazol (relative risk, 3.15; P=0.001) and non-severe aplastic anemia (relative risk, 2.51; P=0.02). Seventeen relapsed patients received additional immunosuppressive therapy with antithymocyte globulin and cyclosporine. Eight patients responded within 6 months. Seven of nine non-responders to second immunosuppressive therapy received hematopoietic stem cell transplantation and five are alive. Eleven patients underwent hematopoietic stem cell transplantation directly and seven are alive.

CONCLUSIONS

In the present study, the cumulative incidence of relapse at 10 years was relatively low compared to that in other studies mainly involving adult patients. A multicenter prospective study is warranted to establish optimal therapy for children with aplastic anemia.

Reduced-intensity conditioning for alternative donor hematopoietic stem cell transplantation in patients with dyskeratosis congenita

DC is an inherited bone marrow failure syndrome mainly characterized by nail dystrophy, abnormal skin pigmentation, and oral leukoplakia. Bone marrow failure is the most common cause of death in patients with DC. Because previous results of HSCT with a myeloablative regimen were disappointing, we used a reduced-intensity conditioning regimen for two patients with classic DC, and one patient with cryptic DC who harbored the TERT mutation. Graft sources included two mismatched-related bone marrow (BM) donors and one unrelated BM donor. Successful engraftment was achieved with few regimen-related toxicities in all patients. They were alive 10, 66, and 72 months after transplantation, respectively. Long-term follow-up is crucial to determine the late effects of our conditioning regimen.

Predicting response to immunosuppressive therapy in childhood aplastic anemia

In aplastic anemia, predictive markers of response to immunosuppressive therapy have not been well defined. We retrospectively evaluated whether clinical and laboratory findings before treatment could predict response in a pediatric cohort from the multicenter AA-97 study in Japan. Between 1997 and 2006, 312 newly diagnosed children were enrolled and treated with a combination of antithymocyte globulin and cyclosporine. In multivariate analyses, lower white blood cell count was the most significant predictive marker of better response; patients with white blood cell count less than 2.0×10(9)/L showed a higher response rate than those with white blood cell count of 2.0×10(9)/L or more (P=0.0003), followed by shorter interval between diagnosis and therapy (P=0.01), and male sex (P=0.03). In conclusion, pre-treatment clinical and laboratory findings influence response to therapy. The finding that response rate worsens with increasing interval between diagnosis and treatment highlights the importance of prompt immunosuppressive therapy for patients with aplastic anemia.

Excellent outcomes of children with CML treated with imatinib mesylate compared to that in pre-imatinib era

Allogeneic hematopoietic stem cell transplantation (HSCT) and tyrosine kinase inhibitor have revolutionized the treatment of patients with chronic myeloid leukemia (CML). In this study, the clinical impact of HSCT and imatinib mesylate (IM) was retrospectively analyzed in 28 children with CML treated in our institutes from 1984 to 2008. Twelve patients were given oral IM. At 36 months after initiation of IM therapy, the complete cytogenetic response rate was 90.9%, and the major molecular response rate was 36.4%. Sixteen children received allogeneic HSCT without administration of IM. The stage of disease at transplantation was: first chronic phase (n = 10), second chronic phase (n = 2), accelerated phase (n = 2), and blastic crisis (n = 2). The progression rate was significantly lower in patients treated with IM than in those treated without IM (0 vs. 28.6%, p = 0.006). In summary, the survival outcomes of pediatric patients with CML were dramatically improved by treatment with IM compared to HSCT.

Spectrum of molecular defects in juvenile myelomonocytic leukaemia includes ASXL1 mutations

Mutations in NF1, PTPN11, NRAS, KRAS and CBL have been reported to play a pathogenetic role in juvenile myelomonocytic leukaemia (JMML), a rare myelodyplastic/myeloproliferative neoplasm occurring in children. Recently, mutations in ASXL1 were identified in chronic myelomonocytic leukaemia and other myeloid malignancies. We sequenced exon 12 of ASLX1 in 49 JMML patients, and found 2 novel heterozygous (nonsense and frameshift) mutations, one occurring as a sole lesion, the other was in conjunction with a PTPN11 mutation. ASXL1 cooperates with KDM1A in transcriptional repression and thereby ASXL1 mutations may synergize with or mimic other JMML-related mutations.

Nocturnal blood glucose and IGFBP-1 changes in type 1 diabetes: Differences in the dawn phenomenon between insulin regimens

OBJECTIVE

Insulin-like growth factor binding protein-1 (IGFBP-1) is known to regulate the bioavailability of insulin-like growth factor (IGF) and the levels of IGFBP-1 are increased in the morning in patients with type 1 diabetes mellitus. We investigated the nocturnal fluctuations of glucose, IGFBP-1, and free IGF-1 levels with three insulin regimens.

RESEARCH DESIGN AND METHODS

Forty-eight type 1 diabetes patients were divided into three groups according to their basal insulin therapy (continuous subcutaneous insulin infusion [CSII], insulin glargine, NPH insulin). Blood samples were obtained every 2 h between 2 300 h and 0700 h to measure plasma glucose, IGFBP-1 and free IGF-1 levels.

RESULTS

The dawn phenomenon was more frequent with NPH (62.1%) than with glargine (16.6%, p<0.05) and CSII (14.3%, p<0.05). In the NPH group, the serum IGFBP-1 levels were markedly increased from 21.0+/-3.6 ng/ml at 2 300 h to 200.3+/-21.8 ng/ml at 0700 h and free IGF-1 levels were inversely decreased; these changes were partially suppressed in the CSII and glargine groups.

CONCLUSIONS

The use of insulin regimens that provide sufficient insulin levels in the early morning can suppress the dawn phenomenon, leading to improved glycemic control. The increase in circulating IGFBP-1 in the morning, as a result of waning of insulin action, lowers free IGF-1 levels and may cause insulin resistance.

Comparison of matched-sibling donor BMT and unrelated donor BMT in children and adolescent with acquired severe aplastic anemia

From January 1991 to March 2007, 61 children and adolescent with acquired severe aplastic anemia received BMT in our institutions. We retrospectively compared the outcome of 30 cases of matched-sibling donor BMT (MSD-BMT) and 31 cases of unrelated donor BMT (URD-BMT). We observed one graft failure among MSD-BMT recipients and three graft failures among URD-BMT recipients, respectively. No patients in the MSD-BMT group developed grades II-IV acute GVHD compared with 11 of 30 patients (37%) in the URD-BMT group (P<0.001). One of 30 MSD-BMT recipients (3%) developed chronic GVHD compared with 8 of 30 URD-BMT recipients (27%) (P=0.013). The incidence of EBV and CMV reactivation was 11 of 20 URD-BMT recipients and 23 of 30, respectively. One patient in the URD-BMT group died of a motor accident 5.5 years after BMT. Ten-year OS was 100% in MSD-BMT recipients and 93.8% (95% CI, 81.9-100%) in URD-BMT recipients, respectively (P=0.252). Ten-year failure-free survival was 96.7% (95% CI, 90.2-100%) in the MSD-BMT group and 84.7% (95% CI, 70.2-99.2%) in the URD-BMT group, respectively (P=0.161).

Treatment of children with refractory anemia: the Japanese Childhood MDS Study Group trial (MDS99)

BACKGROUND

Although hematopoietic stem cell transplantation (HSCT) is offered as a curative therapy for pediatric myelodysplastic syndrome (MDS), it may cause severe complications and mortality. Several reports have shown the efficacy of immunosuppressive therapy (IST) in adult patients with refractory anemia (RA), but its safety and efficacy remains to be fully elucidated in childhood RA.

PROCEDURE

Eleven children diagnosed with RA and enrolled on a prospective multicenter trial conducted by the Japanese Childhood MDS Study Group were eligible for analysis. If patients showed transfusion dependent or suffered from infection due to neutropenia, they received IST consisting of antithymocyte globulin (ATG), cyclosporine (CyA), and methylprednisolone (mPSL).

RESULTS

Eight children received IST, 2 received only supportive therapy, and one underwent HSCT without IST. Five (63%) of eight children who received IST showed hematological response. Of note, one patient showed the disappearance of monosomy 7 after IST. Responders were significantly younger than non-responders (29 months vs. 140 months; P = 0.03). No severe adverse events related to IST were reported in this study. Of 6 children with chromosomal abnormalities who received IST, four showed hematological response. The probability of failure-free and overall survival at 5 years was 63 +/- 17% and 90 +/- 9% respectively.

CONCLUSION

IST is likely to be a safe and effective modality for childhood RA.

Engraftment syndrome following allogeneic hematopoietic stem cell transplantation in children

ES is a complication that occurs immediately before or at the timing of neutrophil engraftment following autologous or allogeneic SCT. It is characterized by fever, skin rash, and non-cardiac pulmonary infiltrates. We evaluated the incidence, risk factors, and outcomes of ES following allogeneic SCT in children. Of 100 pediatric patients, 20 (20%) developed ES occurring at a median of 14 days (range 8-27 days) post-transplant. Patients presented with fever (100%), skin rash (100%), diffuse pulmonary infiltration (25%), and body weight gain (85%). On multivariate analysis, significant risk factors for ES included younger age (<8 yr old) and human leukocyte antigen disparity between donors and recipients. Univariate analysis showed that patients with ES had a higher incidence of developing chronic graft-versus-host disease and ES was not associated with other complications. Event-free survival did not significantly differ between patients with and without ES regardless of the presence of malignant or non-malignant diseases.

Tacrolimus/Methotrexate versus cyclosporine/methotrexate as graft-versus-host disease prophylaxis in patients with severe aplastic anemia who received bone marrow transplantation from unrelated donors: results of matched pair analysis

Tacrolimus (FK) and cyclosporine (CsA) have been shown to be effective in the prophylaxis of graft-versus-host disease (GVHD). However, no comparative studies have yet been conducted to examine the efficacy of FK/methotrexate (MTX) and CsA/MTX in patients with severe aplastic anemia (SAA) given unrelated donor bone marrow transplantation (U-BMT). We used matched-pair analysis to compare FK/MTX with CsA/MTX in patients with SAA who received U-BMT through the Japan Marrow Donor Program. Forty-seven pairs could be matched exactly for recipient age and conditioning regimens. Forty-five patients achieved engraftment in the FK group and 42 patients in the CsA group. The probability of grade II-IV acute GVHD (aGVHD) was 28.9% in the FK group and 32.6% in the CsA group (P=.558). The probability of chronic GVHD (cGVHD) was 13.3% in the FK group and 36.0% in the CsA group (P=.104). The 5-year survival rate was 82.8% in the FK group and 49.5% in the CsA group (P=.012). The study shows the superiority of FK/MTX over CsA/MTX in overall survival because of the lower incidence of transplantation-related deaths. A prospective randomized study comparing FK/MTX and CsA/MTX is warranted.

[Hereditary diseases with propensity to myeloid malignancy]

Hematological malignancy is known to be associated with Down syndrome (DS), neurofibromatosis type 1 (NF1) and congenital bone marrow failure syndromes (CBMFS). Although many responsible germ-cell mutations have been identified, the secondary mutations that are responsible for the development of myelodysplastic syndrome and acute myelogenous leukemia (MDS/AML) have not been determined. Additional chromosomal abnormalities such as monosomy 7 and trisomy 21 are often observed in the progression to MDS/AML, and the critical genes for monosomy 7 have recently been reported. In this review, we briefly present recent findings regarding DS, NF1 and CBMFS with a tendency for malignant transformation; Fanconi anemia, familial platelet disorder with propensity to myeloid malignancy and congenital severe neutropenia.

Downregulation of GATA-2 and overexpression of adipogenic gene-PPARgamma in mesenchymal stem cells from patients with aplastic anemia

Aplastic anemia (AA) is characterized by a reduced number of hematopoietic stem cells and fatty replacement in the bone marrow. Transcriptional factor GATA-2 plays several important roles in both hematopoiesis and adipogenesis. Decreased levels of GATA-2 compromise the proliferation and survival of hematopoietic stem cells. GATA-2 suppresses adipocyte differentiation through direct inhibition of adipogenic factors, including peroxisome proliferator-activated receptor-gamma (PPARgamma). Previous studies have shown that expression of GATA-2 is decreased in marrow CD34-positive cells in AA. To elucidate the mechanisms of fatty marrow replacement, we evaluated the mRNA expression for GATA-2 and PPARgamma in mesenchymal stem cells (MSCs) from patients with AA by quantitative real-time polymerase chain reaction. GATA-2 expression by MSCs from AA patients was significantly lower than in normal subjects. Conversely, expression of PPARgamma was significantly higher in AA patients. Western blot analysis demonstrated that protein levels of GATA-2 were lower in AA patients than those in normal subjects. Moreover, incubation with interferon-gamma induced downregulation of GATA-2 levels in MSCs from normal subjects. These findings indicate that fatty marrow replacement in AA patients can be explained by downregulation of GATA-2 and overexpression of PPARgamma in MSCs. Decreased expression of GATA-2 might be responsible for the pathogenesis and development of the clinical features of the disease.

Cytomegalovirus and Epstein-Barr virus coinfection in three toddlers with prolonged illnesses

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) usually cause primary and latent infections during childhood; thus, coinfection with these viruses occurs occasionally in children. However, its clinical impact has not been established, and may be underestimated. Three cases of coinfection involving these two viruses in toddlers are described: a 14-month-old male with infectious mononucleosis, an 18-month-old female with hemophagocytic lymphohistiocytosis, and a 13-month-old female with acute hepatitis. All three patients had prolonged illnesses. Serial serological testing and quantitation of viral DNA for CMV and EBV using peripheral blood from the patients suggested primary infections with both viruses. In all three cases, the viral load of EBV and CMV in the early stage of disease exceeded 6.4 x 10(3) and 8.8 x 10(2) copies/ml of whole blood, respectively, suggesting that the viruses were associated with the clinical condition. Recognizing that coinfection with these viruses may modulate the clinical course of disease is important.