Genome-wide assessment of genetic risk loci for childhood acute lymphoblastic leukemia in Japanese patients

Not available.

Successful Emergency Decompressive Laminectomy for Burkitt Lymphoma with Metastatic Spinal Lesions: A Case Report

Although Burkitt lymphoma (BL) usually arises in the abdomen or pelvis, it can also arise in the epidural space as a primary or secondary site and present with back pain or limb weakness. Emergency management is necessary to relieve spinal cord compression (SCC). Herein, we report a case of BL with metastatic spinal lesions in a 16-year-old female who presented with sudden-onset progressive walking difficulty. She was admitted to a previous hospital where she presented with abdominal pain and vomiting and was diagnosed with intussusception via a computed tomography scan. Laparoscopic small bowel resection was performed, during which a diagnosis of BL was made on the basis of pathological examination. Sudden numbness in the extremities and the complete inability to walk occurred ten days after surgery. Thoracolumbar MRI revealed a metastatic mass extending from C7 to T6 with evidence of SCC. Emergency decompressive laminectomies (from C7 to T6) and partial debulking of the tumor were performed 12 hours after the onset of her neurologic symptoms. She was subsequently treated with chemotherapy, and she made a complete neurologic recovery. Emergency decompressive laminectomies for BL with spinal lesions could effectively lead to the recovery of neurologic symptoms.

Rare TCF3 variants associated with pediatric B cell acute lymphoblastic leukemia

Germline genetic variants influence development of pediatric B cell acute lymphoblastic leukemia (B-ALL). Genome-wide association studies (GWAS) have identified several pediatric B-ALL susceptibility loci. IKZF1 and PAX5, transcription factors involved in B cell development, have been reported as susceptibility genes for B-ALL development. Therefore, we hypothesized that rare variants of genes involved in B cell development would be candidate susceptibility loci for pediatric B-ALL. Thus, we sequenced TCF3, a key transcription factor gene involving in B cell development. Saliva DNA from 527 pediatric patients with pediatric B-ALL in remission who were registered with the Tokyo Children's Cancer Study Group (TCCSG) were examined. As a TCF3 gene-based evaluation, the numbers of rare deleterious germline TCF3 sequence variants in patients with pediatric B-ALL were compared with those in cancer-free individuals using data in public databases. As a TCF3 single-variant evaluation, the frequencies of rare deleterious germline TCF3 sequence variants in patients with pediatric B-ALL were also compared with those in control data. TCF3 gene-based analysis revealed significant associations between rare deleterious variants and pediatric B-ALL development. In addition, TCF3 variant-based analysis showed particularly strong association between variant rs372168347 (three in 521 TCCSG and three in the 15780 gnomAD whole genome analysis cohort, p = 0.0006) and pediatric B-ALL development. TCF3 variants are known to influence B cell maturation and may increase the risk of preleukemic clone emergence.

A Boy Presenting with a Fever and Pancytopenia Diagnosed with Systemic Lupus Erythematosus without a Positive Anti-ds-DNA Antibody Result or Hypocomplementemia: A Case Report

BACKGROUND

Hematological involvement, including anemia, leukopenia, lymphopenia, and thrombocytopenia, is one of the most common manifestations of childhood-onset systemic lupus erythematosus (cSLE). Specifically, relatively severe forms of hematological involvement, such as macrophage activation syndrome (MAS) and thrombotic microangiopathy, occur in the course of the disease. Positivity for anti-double stranded-DNA (ds-DNA) antibody and hypocomplementemia are important as not only criteria of diagnosing cSLE but also in the determination of the disease activity.

CASE REPORT

A 13-year-old boy without pre-existing disease was referred to our hospital chiefly complaining of a fever for > 7 days, long-lasting malaise, nausea, and non-malar face rash. His blood examination showed pancytopenia and hyperferritinemia, but positive results for anti-ds-DNA antibody and hypocomplementemia were not recognized. Bone marrow aspiration revealed no evidence of malignant diseases, hemophagocytic lymphohistiocytosis, or MAS. A renal biopsy for the differential diagnosis of proteinuria and hematuria revealed class IIIa +V lupus nephritis, leading to the diagnosis of cSLE.

CONCLUSIONS

It is important for cSLE to be considered in patients with pancytopenia, even those without positive anti-ds-DNA antibody findings or hypocomplementemia, and for aggressive approaches to be adopted for the differential diagnosis, including a renal biopsy.

Breath sound analyses of infants with respiratory syncytial virus acute bronchiolitis

INTRODUCTION

The reliability of a breath sound analysis using an objective method in infants has been reported.

OBJECTIVE

Breath sounds of infants with respiratory syncytial virus (RSV) acute bronchiolitis were analyzed via a breath sound spectrogram to evaluate their characteristics and examine their relationship with the severity.

SUBJECTS AND METHODS

We evaluated the inspiratory and expiratory breath sound parameters of 33 infants diagnosed with RSV acute bronchiolitis. The sound powers of inspiration and expiration were evaluated at the acute phase and recovery phase of infection. Furthermore, the relationship between the breath sound parameters and the clinical severity of acute bronchiolitis was examined.

RESULTS

Analyses of the breath sound spectrogram showed that the power of expiration as well as the expiration-to-inspiration sound ratio in the mid-frequency (E/I MF) was increased in the acute phase and decreased during the recovery phase. The E/I MF was inversely correlated with the SpO₂ and positively correlated with the severity score.

CONCLUSION

In infants with RSV acute bronchiolitis, the sound power of respiration was large at the acute phase, significantly decreasing in the recovery phase. In 61% of participants, nonuniform, granular bands were shown in the low-pitched region of the expiratory spectrogram.

Invasive Pulmonary Aspergillosis Successfully Treated with Granulocyte Transfusions Followed by Hematopoietic Stem Cell Transplantation in a Patient with Severe Childhood Aplastic Anemia

Granulocyte transfusions (GTX) have been used in patients with neutropenia or neutropenia associated with invasive fungal infection. An 11-year-old girl with severe aplastic anemia (SAA) received immunosuppressive therapy (IST) with rabbit antithymocyte globulin, cyclosporine, and granulocyte colony-stimulating factor. However, IST was not effective and her condition became complicated with life-threatening invasive pulmonary aspergillosis. Owing to the necessity for early neutrophil recovery to resolve the infection, GTX were performed, followed by bone marrow transplantation (BMT) from her mother with human leukocyte antigen-B locus mismatch. Her dyspnea improved and she eventually became afebrile after the initiation of GTX. Despite engraftment failure following BMT, successful engraftment was achieved by salvage therapy with peripheral blood stem cell transplantation. Chest computed tomography scan obtained 4 months after BMT revealed marked improvement in pneumonia. The current case illustrates that GTX may be useful in controlling invasive fungal infections before hematopoietic stem cell transplantation in patients with SAA.

Anticoagulation treatment and prophylactic edoxaban for cerebral sinus venous thrombosis in an adolescent with acute lymphoblastic leukemia

Pediatric acute lymphoblastic leukemia regimens include large L-asparaginase dosages and steroids, which are associated with an increased risk of venous thromboemboli in adolescents and young adults. Herein, we report the case of an 18-year-old male with acute lymphoblastic leukemia, who was treated with the pediatric regimen, in which edoxaban was employed as a prophylaxis against cerebral sinus venous thrombosis. The event happened on day 20 of induction therapy, when brain magnetic resonance imaging demonstrated a cerebral sinus venous thrombosis in the superior sagittal sinus. Anticoagulation therapy was initiated, and the patient's symptoms disappeared 3 days later. The induction therapy was restarted after an interruption of 16 days, and the consolidation therapies, which included L-asparaginase and steroids, were completed. Edoxaban was administered as a prophylaxis during the consolidation therapy. There were no further adverse events. Edoxaban could be an effective prophylaxis for coagulation complications in adolescents and young adults with acute lymphoblastic leukemia.

Successful combination chemotherapy involving clofarabine, cyclophosphamide, and etoposide for pediatric relapsed acute myeloid leukemia: A case report

Limited salvage chemotherapies are available for relapsed/refractory acute myeloid leukemia. Herein, we described successful reinduction chemotherapy, involving a combination of clofarabine, cyclophosphamide, and etoposide, in a 12-year-old male with relapsed acute myeloid leukemia prior to allogeneic bone marrow transplantation from his father. Although treatment with a combination of fludarabine, cytarabine, granulocyte colony-stimulating factor, idarubicin, and gemtuzumab ozogamicin had no positive effects, the aforementioned clofarabine-based chemotherapy induced complete remission and allowed the transplantation to go ahead. The abovementioned regimen may be useful for induction chemotherapy prior to hematopoietic stem cell transplantation for refractory/relapsed acute myeloid leukemia.

Killer-cell immunoglobulin-like receptor ligand mismatch cord blood transplantation in high-risk neuroblastoma

BACKGROUND

The prognosis of high-risk neuroblastoma stage 4 with bone marrow metastasis, MYCN amplified, or refractory neuroblastoma is poor. To date, no standard treatment has been established. In four selected cases, we challenged the killer-cell immunoglobulin-like receptor ligand mismatch cord blood transplantation in graft-versus-host disease (GVHD) with reduced-intensity conditioning.

METHODS

Prior to this study, conventional chemotherapy, autologous peripheral blood stem cell transplantation with high-dose chemotherapy (busulfan and melphalan), surgery and radiation therapy were completed in every case. The status before cord blood transplantation in two cases was not complete remission (CR) and in the others it was CR. The primary site was the mediastinum, two adrenal glands and a retroperitoneum, respectively. Three patients had bone and bone marrow metastasis and one had MYCN amplification. In all cases, international neuroblastoma pathology classification was unfavorable histology. All patients were >2 years of age.

RESULTS

Relapse occurred only in one patient 17 months after the last transplantation, and the other three patients maintained disease-free survival for 74, 36, and 24 months, respectively. In one case of relapse the disease could be controlled by conventional chemotherapy. Except one, all patients had no severe complications, such as acute or chronic GVHD. One patient had gastric antral vascular ectasia and hemorrhagic cystitis.

CONCLUSION

This strategy might be feasible and should be investigated for efficacy in the future. No definite conclusion can be made, however, due to the very small number of patients. Further prospective studies are required to determine its efficacy.

Gastric antral vascular ectasia in a pediatric patient with neuroblastoma who underwent tandem stem cell transplantation

Gastric antral vascular ectasia (GAVE) is an angiodysplastic disorder, which causes severe and prolonged gastric bleeding. Although GAVE has been described in adult patients treated with hematopoietic stem cell transplantation (HSCT), a few cases involving pediatric patients have also been reported. A 5-year-old boy with neuroblastoma (NB) developed severe hematemesis after undergoing tandem HSCT, i.e. autologous peripheral blood stem cell transplantation (auto-PBSCT), followed by allogeneic cord blood transplantation (allo-CBT). The patient suffered oral feeding difficulties because of the effects of chemotherapy and an unbalanced diet. Intravenous Busulfan (ivBU) was used as a conditioning regimen for the auto-PBSCT. The diagnosis of GAVE was made based on endoscopy of the upper gastrointestinal tract on day 31 after the allo-CBT. Argon plasma coagulation (APC) was performed twice, and the complete resolution of GAVE was confirmed by an endoscopic re-evaluation, conducted on day 87. GAVE in this case might have been associated with ivBU treatment. Atrophy of the gastric mucosa due to loss of appetite might also have contributed to GAVE. NB was treated using high-doses of alkylating agents, such as BU. Such treatment can cause significant mucositis of the oral cavity as well as vascular lesions and is associated with GAVE. Therefore, GAVE should be considered when gastrointestinal bleeding occurs in NB patients treated with HSCT. APC might be effective against HSCT-GAVE.

Prophylactic recombinant thrombomodulin treatment prevents hepatic sinusoidal obstruction syndrome in high-risk pediatric patients that undergo hematopoietic stem cell transplants

Hepatic SOS is a potentially life-threatening complication of conditioning for allogeneic HSCT. rTM is a new drug for treating DIC. We report our experience of the use of rTM as a prophylaxis against SOS in high-risk pediatric patients that underwent HSCT. We evaluated the cases of 19 pediatric hematology and oncology patients who underwent HSCT at our institution between 2007 and 2016. The patients who received HSCT after 2012 (n = 8) were treated with rTM as a prophylaxis against SOS together with UDCA and LMWH, whereas the others (n = 11) were only treated with UDCA and LMWH. Although SOS occurred by post-HSCT day 35 in 3 (27%) patients in the control group, SOS was not seen in the rTM group. Two of the former three patients suffered severe SOS, and one died of the condition. The mean peak level of PAI-1 (a marker of endothelial damage) was significantly lower in the rTM group. rTM appears to be a safe prophylaxis for SOS. The present findings suggest that prophylactic rTM after HSCT might help to prevent SOS.

Treatment outcome of children with acute lymphoblastic leukemia: the Tokyo Children's Cancer Study Group (TCCSG) Study L04-16

The survival rate of children with acute lymphoblastic leukemia (ALL) has increased to approximately 90% after substantial progress in risk-oriented treatment strategies. Between 2005 and 2013, the Tokyo Children's Cancer Study Group (TCCSG) conducted a risk-oriented, non-randomized study, L04-16. The principal aim of this study was to assemble background characteristics and treatment outcomes, and gather genetic information on leukemic cells under central diagnosis. This report outlines the background characteristics and treatment outcomes of 1033 children with ALL treated according to a TCCSG platform. The 5-year event-free and overall survival (OS) rates for all children were 78.1 ± 1.3 and 89.6 ± 1.0%, respectively. The OS rate was significantly higher in children with B-cell precursor (BCP)-ALL (91.9 ± 1.0%, n = 916) than in those with T-ALL (71.9 ± 4.3%, n = 117, p < 0.001). In univariate analysis for BCP-ALL, children aged 1-6 years (5y-OS: 94.2 ± 1.0%), with an initial white blood cell count of < 20,000/μL (94.0 ± 1.0%), high hyperdiploidy (95.4 ± 1.6%), ETV6-RUNX1 (97.4 ± 1.2%) or TCF3-PBX1 (96.9 ± 2.1%), and "Day8NoBlasts" (96.4 ± 1.1%) had the best outcomes. Genetic investigation revealed two novel fusion genes within this cohort: ETV6-ZNF385A and ZNF362-TCF4. Our study highlighted the clinical aspects of genomic features of ALL in Japanese children. We provide fundamental information for the further molecular investigation of this disease.

[Initial presentation of lymphoblastic crisis in a pediatric chronic myelogenous leukemia patient]

A 9-year-old girl was referred to our hospital because of facial palsy. Both physical and blood examination revealed hepatosplenomegaly and leukocytosis, respectively. A bone marrow examination demonstrated marked hypercellularity involving myeloblasts and lymphoblasts. Based on these results, we suspected mixed phenotype acute leukemia. However, her leukemic blasts expressed B-cell antigens, and a chromosomal analysis of her bone marrow cells revealed the following karyotype: 46, XX, t (9;22) (q34;q11.2). All her neutrophils were positive for the breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 fusion protein. Based on these findings, she was diagnosed with a lymphoblastic crisis of chronic myelogenous leukemia (CML). Combined chemotherapy, involving imatinib, resulted in complete molecular remission. She received cord blood transplant (CBT) during the first complete remission; she is alive and has not suffered a relapse since two years after the CBT. The sudden onset of a blastic crisis in pediatric CML is rare, and it may be difficult to distinguish such cases from de novo Ph-positive leukemia. For diagnostic purposes, it is essential to consider a patient's clinical course and blood test results.

Regional evaluation of childhood acute lymphoblastic leukemia genetic susceptibility loci among Japanese

Genome-wide association studies (GWAS) performed mostly in populations of European and Hispanic ancestry have confirmed an inherited genetic basis for childhood acute lymphoblastic leukemia (ALL), but these associations are less clear in other races/ethnicities. DNA samples from ALL patients (aged 0–19 years) previously enrolled onto a Tokyo Children’s Cancer Study Group trial were collected during 2013–2015, and underwent single nucleotide polymorphism (SNP) microarray genotyping resulting in 527 B-cell ALL for analysis. Cases and control data for 3,882 samples from the Nagahama Study Group and Aichi Cancer Center Study were combined, and association analyses across 10 previous GWAS-identified regions were performed after targeted SNP imputation. Linkage disequilibrium (LD) patterns in Japanese and other populations were evaluated using the varLD score based on 1000 Genomes data. Risk associations for ARID5B (rs10821936, OR = 1.84, P = 6 × 10⁻¹⁷) and PIP4K2A (rs7088318, OR = 0.76, P = 2 × 10⁻⁴) directly transferred to Japanese, and the IKZF1 association was detected by an alternate SNP (rs1451367, OR = 1.52, P = 2 × 10⁻⁶). Marked regional LD differences between Japanese and Europeans was observed for most of the remaining loci for which associations did not transfer, including CEBPE, CDKN2A, CDKN2B, and ELK3. This study represents a first step towards characterizing the role of genetic susceptibility in childhood ALL risk in Japanese.

Wiskott-Aldrich syndrome that was initially diagnosed as immune thrombocytopenic purpura secondary to a cytomegalovirus infection

Wiskott–Aldrich syndrome is a rare X-linked recessive disease resulting from variations in the WAS gene. Wiskott–Aldrich syndrome is sometimes difficult to differentiate from immune thrombocytopenic purpura. A 2-month-old boy was admitted to our hospital for purpura and thrombocytopenia. His mean platelet volume was reported to be normal. Treatment with intravenous immunoglobulins failed to improve the patient’s platelet count. Subsequently, an acute cytomegalovirus infection was confirmed by serological testing and antigenemia. The patient was diagnosed with immune thrombocytopenic purpura secondary to a cytomegalovirus infection. However, based on the patient’s clinical course and the refractoriness of his condition, Wiskott–Aldrich syndrome was strongly suspected. Through direct sequencing of the genomic DNA of the Wiskott–Aldrich syndrome protein (WASP) gene, we identified a novel missense mutation in exon 3 of the patient’s WASP gene (c. 343 C>T, p. H115T), and the patient was diagnosed with Wiskott–Aldrich syndrome at 3 months after onset. Children with Wiskott–Aldrich syndrome are often initially diagnosed with immune thrombocytopenic purpura, which can lead to inappropriate treatment and delays to life-saving definitive therapy. Our findings imply that Wiskott–Aldrich syndrome should be considered as a differential diagnosis in cases of refractory immune thrombocytopenic purpura combined with a cytomegalovirus infection.

A snapshot on prokaryotic diversity of the Solimões River basin (Amazon, Brazil)

The Amazon region has the largest hydrographic basin on the planet and 
is well known for its huge biodiversity of plants and animals. However, 
there is a lack of studies on aquatic microbial biodiversity in the 
Solimões River, one of its main water courses. To investigate the 
microbial biodiversity of this region, we performed 16S rRNA gene clone 
libraries from Solimões River and adjacent rivers and lakes. Our question was which microorganisms inhabit the different types of aquatic 
environments in this part of the basin, and how diversity varies among 
these environments (rivers and lakes). The microbial 
diversity generating 13 clone libraries of the bacterial 16S rRNA gene 
and 5 libraries of the archaeal 16S rRNA gene was assessed. Diversity measured by several alpha diversity indices (ACE, Chao, Shannon and Simpson) revealed significant differences in diversity indices between lake and river samples. The site with higher microbial diversity was in the Solimões River (4S), downstream the confluence with Purus River. The most common bacterial taxon was the cosmopolitan Polynucleobacter genus, widely observed in all samples. The phylum Thaumarchaeota was the prevailing archaeal taxon. Our results provide the first insight into the microbial diversity of the world's largest river basin.

Successful low-dose radiotherapy treatment for Kasabach-Merritt syndrome

Kasabach-Merritt syndrome (KMS) is characterized by hemangioma associated with life-threatening thrombocytopenia, and is a consumptive coagulopathy. Although treatments available include corticosteroids, α-interferon, vincristine, and surgery, response may be unsatisfactory, and the mortality rate remains at approximately 30%. Although radiotherapy has been used effectively for KMS, it may cause growth retardation and secondary malignancy. We report a case of KMS in which hemangioma of the left thigh was successfully treated with low-dose radiotherapy (6 Gy in six fractions, weekly) after failure of corticosteroid therapy. No significant late effects due to the radiotherapy were noted at 5 year follow up. Thus, low-dose radiotherapy remains an important treatment method for KMS when patients fail to respond to other treatments.

Lignocellulolytic enzymes and bacteria associated with the digestive tracts of Stenochironomus (Diptera: Chironomidae) larvae

We analyzed the digestive activity of the enzymes that digest cellulose and hemicellulose and the bacterial community that is capable of hydrolyzing wood compounds in the digestive tracts of Stenochironomus (Diptera: Chironomidae) larvae, which are miners of decomposing submerged tree and bush branches. Based on quantification of reducing sugars, these larvae have a limited capacity for cellulose degradation but a good capacity for xylan hydrolysis. We isolated 31 types of colonies from two larval morphotypes, of which 19 tested positive for the capacity to hydrolyze at least one of the four substrates that were used as the main carbon source in the culture media. Their woody compound degradation capacity was assessed using colorimetric tests. The bacteria were identified by the analysis of the 16S rRNA gene. None of the bacteria were capable of degrading lignin. The genus Pseudomonas had the greatest species richness; Bacillus spp exhibited the greatest capacity for degrading the different substrates, and Sphingobium was found in both morphotypes. Microorganisms participate in the degradation of wood consumed by Stenochironomus larvae. This is the first report of lignocellulolytic bacteria and enzymes in the digestive tracts of mining chironomids.

Quality of long-term cryopreserved umbilical cord blood units for hematopoietic cell transplantation

The aim of this study was to evaluate the quality of long-term cryopreserved umbilical cord blood (CB) units for hematopoietic cell transplantation (HCT). The recovery of the number of total nucleated cell (TNC), hematopoietic progenitor cells (HPCs; CD34+ cells, colony-forming units-granulocyte/macrophages [CFU-GMs]), and the percentage of viable cells, CD34+ CD38- cells, and CD34+ CXCR4+ cells of CB units cryopreserved for 10 years for HCT were examined. Eighteen CB units cryopreserved for 10 years (as the study group) and for 1 month (as the control group), respectively, were analyzed. The recovery rate of TNC, CD34+ cells and CFU-GMs were 88.72 ± 16.40, 68.39 ± 18.37 and 42.28 ± 38.16% for the study group and 80.17 ± 14.46, 72.67 ± 20.38 and 49.61 ± 36.39% for the control group (p = 0.106, p = 0.513 and p = 0.559, respectively). There were no significant differences in the recovery rate of TNC, CD34+ cells and CFU-GMs between the study group and the control group. The mean basal percentage of viable cells, CD34+ CD38- cells, and CD34+ CXCR4+ cells after thawing were 83.69 ± 9.45, 9.11 ± 4.13 and 81.65 ± 10.82% for the study group. These results indicate that long-term cryopreservation does not negatively affect the quality of CB units for HCT.

Acute megakaryocytic leukemia (AMKL,FAB;M7) with Beckwith-Wiedemann syndrome

Beckwith-Wiedemann syndrome (BWS) is characterized by an accumulation of multiple congenital anomalies. Although patients with BWS are known to have a higher incidence of embryonal tumors, there has been no reports associated with acute leukemia. This report describes the case of a patient with BWS who developed Acute Megakaryocytic Leukemia (AMKL,FAB;M7). Because most patients with BWS present gigantism, the therapy-related toxicity of chemotherapy can be a very serious problem. This patient exhibited no therapy-related toxicity after chemotherapy, suggesting that acute leukemia with BWS may not require a reduction in dosage.

Disseminated intravascular coagulation complicating acute lymphoblastic leukemia: a study of childhood and adult cases

A high incidence of disseminated intravascular coagulation (DIC) in adult patients with acute lymphoblastic leukemia (ALL) is reported. However, studies comprising both childhood and adult patients are sparse and the clinical relevance of DIC in ALL patients has been a conflicting issue. Coagulation profiles at presentation and within seven days after starting remission-induction therapy of 44 childhood and 51 adult ALL patients were studied. At presentation, two childhood (5%) and 11 adult (22%) patients had DIC (p<0.05). After starting therapy, four of 27 childhood (15%) and 14 of 33 adult (42%) patients screened for coagulopathy developed DIC (p<0.05). Overall, six of the 44 children (14%) and 25 of the 51 adults (49%) were complicated with DIC (p<0.001). In the adult cases, DIC was more frequently complicated with FAB subtype L2 than L1 (p<0.05). All hemorrhages seen in the childhood cases were minor hemorrhages. In the adult patients, two patients with DIC had WHO grade 3 hemorrhage and the other hemorrhagic complications were minor hemorrhages. While milder induction therapies starting with corticosteroid given for childhood cases should be taken into consideration when comparing the incidences of DIC after therapy, the findings indicated that childhood and adult ALL may differ in the procoagulant characteristics. Morphological distinction between L1 and L2 appears to have relevance in the procoagulant activity in adult ALL. DIC complicating ALL is generally mild, however, sometimes causes severe hemorrhages in adults.