Impact of immunophenotypic characteristics on genetic subgrouping in childhood acute lymphoblastic leukemia: Tokyo Children's Cancer Study Group (TCCSG) study L04-16

Immunophenotyping was performed in 1044 consecutive childhood acute lymphoblastic leukemia (ALL) patients enrolled in the Tokyo Children's Cancer Study Group L04-16 trial, revealing novel findings associated with genetic abnormalities. In addition to TCF3-PBX1 and MEF2D fusions, the CD10⁽⁺⁾ subtype of KMT2A-MLLT3-positive ALL frequently exhibited the cytoplasmic-μ⁽⁺⁾ pre-B ALL immunophenotype. Although ETV6-RUNX1 was significantly correlated with myeloid antigen expression, more than half of patients expressed neither CD33 nor CD13, while the CD27⁽⁺⁾ /CD44^(-) immunophenotype was maintained. Expression of CD117 and CD56 in B-cell precursor-ALL was limited to certain subtypes including ETV6-RUNX1 and KMT2A-MLLT3. Besides BCR-ABL1, CRLF2, hyperdiploidy, and hypodiploidy, CD66c was also expressed in Ph-like kinase fusion-, PAX5 fusion-, and DUX4 fusion-positive ALL, but not in MEF2D fusion-positive ALL, indicating constant selectivity of CD66c expression. In T-ALL, SIL-TAL1-positive patients were likely to exhibit a more mature immunophenotype. Expression of CD21 and CD10 was not rare in T-ALL, while lack of CD28 was an additional feature of early T-cell precursor-ALL. Considering the immunophenotype as a prognostic maker, MEF2D fusion-positive ALL with CD5 expression may be associated with a poorer prognosis in comparison with those lacking CD5 expression. In cases with characteristic marker expression, the presence of certain fusion transcripts could be predicted accurately.

Long-term outcomes of children with extracutaneous juvenile xanthogranulomas in Japan

BACKGROUND

Juvenile xanthogranuloma (JXG) is the most common non-Langerhans cell histiocytosis in children. The mortality and morbidity of JXG with extracutaneous lesions remain unclear.

METHODS

Data of patients aged < 18 years who were diagnosed with JXG between 2001 and 2010 were retrospectively collected through a nationwide survey.

RESULTS

Twenty patients (11 male and nine female) had extracutaneous lesions. The median observation time was 10 years (range, 0-17). Six patients presented with symptoms at birth. The median age at diagnosis was 8.5 months (range, 0 month-13 years). Fifteen patients underwent treatment for JXG, including chemotherapy (n = 11), and five did not receive treatment. All patients except one survived; 17 were disease-free and two survived with disease. One newborn-onset patient with liver, spleen, and bone marrow involvement died of the disease. Permanent sequelae included central diabetes insipidus, growth hormone deficiency, and panhypopituitarism detected at diagnosis in three, one, and two patients, respectively. Four patients had visual impairment (optic nerve compression and intraocular invasion in two each), three had epilepsy, one had mental retardation, and one had a skin scar. Eight patients who had intracranial lesions were older at diagnosis, and had a higher frequency of disease-related comorbidities and permanent sequelae than those without intracranial involvement.

CONCLUSIONS

Patients with extracutaneous JXG had good outcomes, although those with intracranial lesions had serious permanent sequelae. Effective and safe treatment regimens for patients with intracranial JXG need to be developed.

Transfusion outcome for volume- and plasma-reduced platelet concentrates for pediatric patients

BACKGROUND AND OBJECTIVES

Plasma reduction in platelet concentrate (PC) products has been reported to prevent large volume load and transfusion-related adverse reactions (TRARs). However, volume reduction might be associated with a poor transfusion response because of a deterioration in platelet (PLT) quality. Because PLT quality control and transfusion responses for recently washed PCs using PLT additive solutions are superior, we investigated the clinical safety and transfusion efficacy of volume-reduced washed PCs in pediatric patients.

MATERIALS AND METHODS

We prepared a simplified resuspended PC product (RPC) as a washed PC. Regular RPC (R-RPC) included equivalent volumes of bicarbonate Ringer's solution and anticoagulant citrate dextrose solution A (BRS-A) as the resuspension solution. Half RPC (H-RPC) was prepared by adding a half volume of BRS-A. Twenty-four pediatric patients were scheduled for transfusions with R-RPC and H-RPC up to 4 times. R-RPC was transfused 42 times into 24 patients. H-RPC was transfused 41 times into 23 patients.

RESULTS

Neither product was observed to cause TRARs. Although the calculated PLT recovery for H-RPC was significantly reduced, the posttransfusion corrected count increment (24 h) did not differ. Moreover, similar results were observed for vital signs during transfusion.

CONCLUSION

Volume-reduced washed PC can be transfused without causing TRARs, differences in vital signs, or inferior transfusion responses. Volume-reduced washed PC also provides the advantages of shortened transfusion times and reduced volume loads. Although a standard technique for stable resuspension is necessary, volume-reduced washed PC may be a beneficial option for children, including neonates, or individuals with cardiovascular or renal problems.

Thyroid tumor surveillance using ultrasound in childhood cancer survivors

BACKGROUND

The optimal method for thyroid cancer screening in childhood cancer survivors (CCSs) who received radiation involving the thyroid gland is still debated. We describe a case series of ultrasound surveillance for thyroid tumor in CCSs in our institute.

METHODS

We conducted thyroid tumor surveillance for CCSs with a history of radiation therapy involving the thyroid. The basic screening method was palpation. Thyroid ultrasound was also performed for patients who agreed after its benefits and risks were explained to them. We surveyed CCSs who visited the long-term follow-up outpatient clinic in our institution between October 2014 and September 2018.

RESULTS

Of 82 CCSs who visited our institution during the study period, 44 were eligible for inclusion. None had a mass identified by palpation. Thyroid ultrasound was performed in 39 CCSs, and we identified thyroid nodules in 27. Four patients had a nodule with malignant echo features. Two of these cases received biopsies, and one patient was ultimately diagnosed with an early stage thyroid carcinoma.

CONCLUSIONS

Childhood cancer survivors irradiated in the thyroid had a higher prevalence of thyroid nodules than the general population. Ultrasound screening contributed to early detection of impalpable thyroid cancer and enabled us to perform minimal surgery. Thus, ultrasound appears to be a useful option for secondary thyroid cancer screening. The thyroid tumor surveillance modality should be considered according to the individual case, and the patient must receive a clear explanation of the benefits and risks. These results could help doctors consider how to screen for secondary thyroid cancer.

Hematopoietic stem cell transplantation for pediatric acute promyelocytic leukemia in Japan

BACKGROUND

The number of hematopoietic stem cell transplantation (HSCT) procedures performed for pediatric acute promyelocytic leukemia (APL) has decreased in the all-trans retinoic acid (ATRA) era. Although HSCT is still widely adopted as part of salvage therapy for relapsed patients, there is no general consensus about the optimal transplant type (autologous [auto-HSCT] or allogeneic HSCT [allo-HSCT]).

PROCEDURES

We retrospectively reviewed the clinical data of 95 childhood APL patients who underwent their first HSCT between 1990 and 2014. Of the 95 patients, 40 (42%), 41 (43%), and 3 (3%) underwent HSCT procedures after achieving their first complete remission (CR1), CR2, and CR3, respectively, and 11 (12%) underwent HSCT while in a non-CR state.

RESULTS

The non-CR group exhibited significantly worse five-year overall survival (5yOS) and disease-free survival (5yDFS) (5yOS: 46%; 5yDFS: 46%) than the CR1 (5yOS: 80%; 5yDFS: 78%) and CR2 + CR3 groups (5yOS: 81%; 5yDFS: 76%) (P = 0.013 and P < 0.01, respectively). Of the patients treated in CR2, no significant differences in 5yOS or the five-year cumulative incidence of relapse (5yRI) were detected between the auto-HSCT and allo-HSCT groups (5yOS: 85%, vs 78%, P = 0.648; 5yRI: 9%, vs 11%, P = 0.828). Among the patients who underwent allo-HSCT in CR2, those with matched sibling donors displayed a significantly higher 5yRI (33%) than those with other types of donors (0%, P = 0.015).

CONCLUSIONS

Even after relapsing, childhood APL can be cured with HSCT if CR is achieved. These findings demonstrate that achieving CR followed by HSCT is the preferred strategy for treating children with relapsed or refractory APL.

Impact of infliximab administration before plasma exchange therapy on patients with Kawasaki disease

Plasma exchange is a therapeutic option in refractory Kawasaki disease (KD). However, the effects of other immunosuppressive treatments on plasma exchange therapy have not been studied. We investigated the effect of infliximab on plasma exchange in KD as well as on the outcome in patients with KD. We studied 16 patients with intravenous immunoglobulin-resistant KD who finally underwent plasma exchange. The patients were divided into two groups: patients who received infliximab before plasma exchange (infliximab group) and patients who did not (non-infliximab group). The infliximab group showed a lesser median number of required total plasma exchange sessions (P = .002) and higher change and reduction rates in C-reactive protein before and after the first plasma exchange (both P = .027) than that of the non-infliximab group. Infliximab administered before plasma exchange reduced the number of total plasma exchange sessions and improved the plasma exchange efficacy.

Comparative analysis of graft-versus-host disease prophylaxis with tacrolimus in combination with methylprednisolone or methotrexate after umbilical cord blood transplantation

Post-transplant early immune disorders and engraftment failure/delay are major issues in unrelated umbilical cord blood transplantation (UCBT). We evaluated graft-versus-host disease (GVHD) prophylaxis approaches after UCBT by comparing UCBT outcomes with GVHD prophylaxis using tacrolimus plus methylprednisolone (Tac/mPSL, n = 32) to that with Tac plus methotrexate (Tac/MTX, n = 31) at a single pediatric transplantation center. The 30-day cumulative incidence rates of neutrophil engraftment and median neutrophil engraftment times in the Tac/mPSL and Tac/MTX groups were 70.1% and 90.3% and 19 and 17 days, respectively (p = 0.09). Pre-engraftment immune reactions (PIR) and acute GVHD were improved with Tac/MTX; PIR incidence (p = 0.020) and cumulative incidence of 100-day acute GVHD (grade II-IV, 38.7% vs 68.8%, p = 0.045; grade III-IV, 9.7% vs 34.4%, p = 0.021) were significantly lower in the Tac/MTX group than in the Tac/mPSL group. However, the incidence rates of relapse (p = 0.921) and cytomegalovirus reactivation (p = 0.908), and the estimated overall (p = 0.87) and event-free survival (p = 0.88) were comparable between the two groups. These data indicate that GVHD prophylaxis with Tac/MTX is associated with favorable results, including reduced PIR and acute GVHD incidence after UCBT, without adverse effects.

PCDH17 functions as a common tumor suppressor gene in acute leukemia and its transcriptional downregulation is mediated primarily by aberrant histone acetylation, not DNA methylation

We recently reported that methylation of PCDH17 gene is found in 30% of children with B-cell precursor acute lymphoblastic leukemia (ALL), and is significantly correlated to event-free or overall survival. We here evaluated PCDH17 mRNA expression in pediatric acute myeloid leukemia (AML) and ALL. PCDH17 mRNA expression levels in children with ALL/AML were lower than those in healthy counterparts. We next elucidated the mechanism underlying down-regulation of PCDH17 mRNA, using myeloid and lymphoid leukemic cell lines. Treatment with the histone deacetylase inhibitor trichostatin A (TSA) resulted in restoration of PCDH17 mRNA expression and growth inhibition in K562, HL60, REH, and RCH-ACV cell lines. Upregulation of PCDH17 mRNA expression resulted from histone H3 acetylation. Knockdown of the PCDH17 gene, caused by transduction of PCDH17-targeted shRNA, significantly enhanced the proliferation of KU812 cells. Meanwhile, overexpression of PCDH17 via retroviral-particle transfection substantially inhibited the growth of Kasumi1 cells. The fold-increase in PCDH17 mRNA expression mediated by 5-azacytidine, an inhibitor of DNA methyltransferase, was fundamentally lower than that produced by TSA. In conclusion, our results suggest that PCDH17 gene functions as a common tumor suppressor gene in leukemic cells, and that histone deacetylase inhibitors re-express PCDH17 mRNA to a greater extent than demethylation reagents.

P5652Catheter ablation outcome and heart failure hospitalization in atrial fibrillation patients with preserved left ventricular ejection fraction: insights from the Kansai plus atrial fibrillation (KPAF)

Background

Heart failure (HF) is the leading cause of death in patients with atrial fibrillation (AF), and AF is an independent prognostic factor in HF patients with preserved left ventricular ejection fraction (LVEF). Radiofrequency catheter ablation (RFCA) for AF is effective to maintain sinus rhythm.

Purpose

We sought to clarify incidence of HF hospitalization and whether AF ablation outcome influenced incidence of HF hospitalization after the procedures in patients with preserved LVEF.

Methods

We conducted a large-scale, prospective, multicenter, observational study. A total of 4522 consecutive patients with normal LVEF (>/- 50%) who underwent an initial RFCA for AF in 26 centers were enrolled (average age, 64±10 years; non-paroxysmal AF, 33.7%). The median follow-up duration was 2.9 years.

Results

The 3-year cumulative incidence of AF recurrence after a single procedure was 40.3%. Hospitalization for HF was observed in 60 patients (1.3%) and was significantly higher in patients with AF recurrence than those without it (2.63% vs 0.44%, log-rank p<0.001). After adjustment by age ≥65 years, estimated glomerular filtration rate ≤60ml/min, history of HF, and female, all of which were statistically associated with a risk of HF hospitalization, AF recurrence after the index RFCA was an independent predictor of HF hospitalization (hazard ratio; 4.75, 95% confidence interval; 2.59–9.42, p<0.001).

Conclusions

Recurrence after RFCA for AF was a significant risk of HF hospitalization among AF patients with preserved LVEF.

Acknowledgement/Funding

This study was supported by the Research Institute for Production Development in Kyoto, Japan.

P1035Factors associated with quality-of-life improvement after catheter ablation of atrial fibrillation: insights from the Kansai Plus Atrial Fibrillation (KPAF) registry

Background

Improving the quality of life (QoL) is one of the main purposes of catheter ablation (CA) of persistent atrial fibrillation (AF). Factors associated with QoL improvement after CA of AF patients have not been clarified. The Kansai Plus Atrial Fibrillation (KPAF) Registry is a multi-center registry enrolling more than 5,000 consecutive patients undergoing the first radiofrequency catheter ablation of AF.

Purpose

The aim of this study was to investigate the QoL change after AF ablation and its associated factors.

Methods

A total of 2030 patients in whom the QoL score was assessed before and one year after the ablation were enrolled from the KPAF registry (age 64±10 years, 75% male, paroxysmal 66%, CHADS2 score 1.1±1.1). The QoL was evaluated using the AF specific QoL evaluation method (AFQLQ), which scores the patient QoL within a range of 0–98 points.

Results

Overall, catheter ablation showed a significant increase in the AFQLQ score (68±19 vs. 86±13 points, P<0.01). AF recurrence was observed in 372 cases (18%) during a 1-year follow-up period. A multivariate analysis showed that AF recurrence, symptomatic AF, long AF duration, high preprocedural heart rate (>110 bpm) and small left atrial diameter were independent predictors of a QoL improvement defined as a >10% score increase.

Multivariate analysis

Conclusions

CA of AF significantly improved the QoL. AF recurrence was one of the strong factors associated with QoL improvement. Symptomatic AF, long AF duration, high preprocedural heart rate and small left atrial diameter were independent predictors of QoL improvement.

Retrospective analysis of children with high-risk acute myeloid leukemia who underwent allogeneic hematopoietic stem cell transplantation following complete remission with initial induction chemotherapy in the AML-05 clinical trial

In the AML-05 clinical trial conducted by the Japanese Pediatric Leukemia/Lymphoma Group from 2006 to 2010, children with high-risk acute myeloid leukemia (HR AML) received allogeneic hematopoietic stem cell transplantation (allo-HSCT) at first complete remission (CR1). The aim of this study was to investigate the impact of allo-HSCT on the outcome of HR AML. Patients with either monosomy 7, 5q-, t(16;21), Ph1, FLT3-ITD, or induction failure after the first course of chemotherapy were eligible for transplant. Of 53 children with HR AML, 51 received allo-HSCT-45 in CR1, five in CR2, and one with non-CR. t(8;21), t(9;11), and t(16;21) abnormalities were identified in eight, five, and four patients, respectively. The stem cell sources varied-bone marrow in 30 patients, peripheral blood in three, and cord blood in 18. The median follow-up was 62 months. The overall survival (OS) rates at 3 years were 73% and 25% for patients who received transplant at CR1 and ≥CR2, respectively. Multivariable analysis showed that patients with chronic graft-versus-host disease (cGVHD) had better OS. This study supports that allo-HSCT is a suitable treatment for HR AML in CR1. The favorable outcome associated with cGVHD indicates that a graft-versus-leukemia effect might be occurring.

P1029Catheter ablation outcome and heart failure hospitalization in atrial fibrillation patients: insights from the Kansai plus atrial fibrillation (KPAF) registry

Background

Heart failure (HF) is the leading cause of death in patients with atrial fibrillation (AF). Radiofrequency catheter ablation (RFCA) for AF is effective to maintain sinus rhythm.

Purpose

We sought to clarify whether AF ablation outcome influenced incidence of HF hospitalization after the procedures.

Methods

We conducted a large-scale, prospective, multicenter, observational study. A total of 5010 consecutive patients who underwent an initial RFCA for AF in 26 centers were enrolled (average age, 64±10 years; non-paroxysmal AF, 35.6%). The median follow-up duration was 2.9 years.

Results

The 3-year cumulative incidence of AF recurrence after a single procedure was 40.2%. The 3-year incidence of hospitalization for HF was observed in 92 patients (1.8%) and was significantly higher in patients with AF recurrence than those without it (3.3% vs 0.84%, log-rank p<0.001). After adjustment by advanced age,(≥65 years), reduced left ventricular ejection fraction (≤50%), low estimated glomerular filtration rate (≤60ml/min), and history of HF, all of which were statistically associated with a risk of HF hospitalization (p<0.1, respectively), AF recurrence after the index RFCA was an independent predictor of HF hospitalization (hazard ratio [HR]; 3.17, 95% confidence interval [CI]; 2.06–5.04, p<0.001).Even after multiple procedures (1425 re-ablation sessions in 1274 patients [25.4%]), AF recurrence after the last procedure was an independent predictor of HF hospitalization (HR; 2.83, 95% CI; 1.89–4.24, p<0.001).

Conclusions

Among AF patients receiving RFCA, those with AF recurrence were at greater risk of heart failure hospitalization than were patients without AF recurrence. These differences should be noted when treating AF patients in actual clinical practice.

Acknowledgement/Funding

This study was supported by the Research Institute for Production Development in Kyoto, Japan.

P5650Improvement in ejection fraction predicts heart failure after catheter ablation for atrial fibrillation in patients with left ventricular systolic dysfunction: from the KPAF registry

Introduction

The presence of atrial fibrillation (AF) in patients with reduced left ventricular ejection fraction (LVEF) is associated with increased risks of mortality and hospitalization for heart failure (HF). Although prior studies reported that catheter ablation (CA) for AF in low LVEF patients reduced risks of all-cause mortality and HF hospitalization, the predictors of worsening HF after ablation has not been adequately evaluated.

Purpose

The purpose of this study was to investigate the impact of improvement in LVEF after AF ablation on the incidence of subsequent HF hospitalization in patients with low LVEF.

Methods

The Kansai Plus Atrial Fibrillation (KPAF) Registry is a multicenter registry enrolling 5,013 consecutive patients undergoing first-time ablation for AF. The current study population consisted of 1,031 patients with reduced LVEF of <60%. We divided the study population into 3 groups according to LVEF at follow-up; 678 patients (65.8%) with improved LVEF (≥5 U change in LVEF), 288 patients (27.9%) with unchanged LVEF (−5 U ≤ change in LVEF <5 U) and 65 patients (6.3%) with worsened LVEF (<−5 U change in LVEF).

Results

During the median follow-up of 1067 [879–1226] days, patients improved LVEF had lower rate of HF hospitalization, compared with those with unchanged and worsened LVEF (2.1%, 8.0%, and 21.5%, respectively, P<0.0001). Recurrent atrial tachyarrhythmias were documented in 43.5%, 47.2% and 67.7%, respectively (P=0.0008).

Figure 1

Conclusion

Among patients with reduced LVEF undergoing AF ablation, patients with subsequently improved LVEF in association with maintained sinus rhythm had markedly lower risk of HF hospitalization during follow-up as compared with those with unchanged or worsened LVEF.

Alcohol Consumption During Pregnancy and Risk of Placental Abnormality: The Japan Environment and Children's Study

There have been no large nationwide birth cohort studies examining for the effects of maternal alcohol use during pregnancy on placental abnormality. This study searched for associations between alcohol consumption and the placental abnormalities of placenta previa, placental abruption, and placenta accreta using the fixed dataset of a large national birth cohort study commencing in 2011 that included 80,020 mothers with a singleton pregnancy. The presence of placental abnormalities and potential confounding factors were recorded, and multiple logistic regression analysis was employed to search for correlations between maternal alcohol consumption during pregnancy and placental abnormalities. The overall rate of prenatal drinking until the second/third trimester was 2.7% (2,112). The prevalence of placenta previa, placental abruption, and placenta accreta was 0.58% (467), 0.43% (342), and 0.20% (160), respectively. After controlling for potential confounding factors, maternal alcohol use during pregnancy was significantly associated with the development of placenta accreta (OR 3.10, 95%CI 1.69-5.44). In conclusion, this large nationwide survey revealed an association between maternal drinking during pregnancy and placenta accreta, which may lead to excessive bleeding during delivery.

A low-frequency IL4R locus variant in Japanese patients with intravenous immunoglobulin therapy-unresponsive Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis which may be associated with coronary artery aneurysms. A notable risk factor for the development of coronary artery aneurysms is resistance to intravenous immunoglobulin (IVIG) therapy, which comprises standard treatment for the acute phase of KD. The cause of IVIG resistance in KD is largely unknown; however, the contribution of genetic factors, especially variants in immune-related genes, has been suspected.

METHODS

To explore genetic variants related to IVIG-unresponsiveness, we designated KD patients who did not respond to both first and second courses of IVIG therapy as IVIG-unresponsive patients. Using genomic DNA from 30 IVIG-unresponsive KD patients, we performed pooled genome sequencing targeting 39 immune-related cytokine receptor genes.

RESULTS

The single nucleotide variant (SNV), rs563535954 (located in the IL4R locus), was concentrated in IVIG-unresponsive KD patients. Individual genotyping showed that the minor allele of rs563535954 was present in 4/33 patients with IVIG-unresponsive KD, compared with 20/1063 individuals in the Japanese genome variation database (odds ratio = 7.19, 95% confidence interval 2.43-21.47). Furthermore, the minor allele of rs563535954 was absent in 42 KD patients who responded to IVIG treatment (P = 0.0337), indicating that a low-frequency variant, rs563535954, is associated with IVIG-unresponsiveness in KD patients. Although rs563535954 is located in the 3'-untranslated region of IL4R, there was no alternation in IL4R expression associated with the mior allele of rs563535954. However, IVIG-unresponsive patients that exhibited the minor allele of rs563535954 tended to be classified into the low-risk group (based on previously reported risk scores) for prediction of IVIG-resistance. Therefore, IVIG-unresponsiveness associated with the minor allele of rs563535954 might differ from IVIG-unresponsiveness associated with previous risk factors used to evaluate IVIG-unresponsiveness in KD.

CONCLUSION

These findings suggest that the SNV rs563535954 could serve as a predictive indicator of IVIG-unresponsiveness, thereby improving the sensitivity of risk scoring systems, and may aid in prevention of coronary artery lesions in KD patients.