Acute Lymphoblastic Leukemia Patients In Remission Research Articles

Exposure to a mycovirus containing Aspergillus Flavus reproduces acute lymphoblastic leukemia cell surface and genetic markers in cells from patients in remission and not controls

The etiology of acute lymphoblastic leukemia (ALL) remains unknown. A recent “two-hit” model for the occurrence of precursor B cell acute lymphoblastic leukemia propose that this disease arises through a two-step process, including predisposing genetic mutation and exposure to infections. While several genetic mutations are proposed, no infection category has been suggested. We have isolated a certain Aspergillus Flavus from residence of an ALL patient. This organism contains mycovirus and does not produce aflatoxin. The supernatant of culture of this mycovirus containing Aspergillus Flavus (SAF) was tested on the PBMCs of ALL patients in remission and controls. Cell surface phenotypes and genetic markers were examined. The effects of its combination with Epstein-Barr virus (EBV) was also investigated. For the SAF, positive and negative controls were aflatoxin and culture of Mycocladus corymbifer, respectively. Controls for ALL were sickle cell patients undergoing exchange transfusion. Incubation of the PMBCs from ALL patients in remission, or controls, with SAF resulted in re-development of ALL cell surface phenotypes and genetic markers in ALL patients in remission and not controls. These differentiating effects were not seen with aflatoxin or culture of Mycocladus Corymbifer. Addition of EBV did not alter effects of SAF. Currently, there are no techniques to discriminately reproduce characteristic leukemic genetic markers and cell surface phenotypes in cells from ALL patients in remission and not controls. These studies may provide a test for recognition of ALL patients in remission and new prospects for the investigation of leukemogenesis.

Association of Germline Variants of TCF3 and PAX5 with Pediatric Acute Lymphoblastic Leukemia Development

Background: The development of B-lymphocyte is controlled by the coordinated action of transcription factors networks, such as IKZF1, TCF3, EBF1 or PAX5. It is increasingly recognized that germline variants of those genes which disrupt their function are responsible for inborn errors of humoral immunity. Meanwhile, it is well understood genetic alterations of those molecules are frequently altered in B-lineage acute lymphoblastic leukemia (ALL) and are associated with leukemogenesis. However, those involvements are usually attributed to somatic mutation. Germline variations may also trigger cancer development in some cases. For instance, genome-wide association studies (GWAS) have identified B-cell precursor (BCP-) ALL susceptibility variants within IKZF1. Furthermore, germline variants of IKZF1, TCF3, and PAX5 are reported to be associated with B-ALL development. Therefore, we hypothesize that attenuated function due to germline variation in those genes may predispose to ALL development in Japanese population to some extent. Method: Saliva DNA from 583 pediatric ALL patients in remission registered in Tokyo Children's Cancer Study Group (TCCSG) were analyzed in this study. Targeted sequencing for exons and exon-intron boundaries of IKZF1, TCF3, and PAX5 was performed using next-generation sequencer. Frequency of the detected variant alleles was compared to data from the Exome Aggregation Consortium (ExAC) East Asian Cohort (n=4327), Tohoku Medical Megabank Organization (ToMMo) cohort (n=3554), and the Human Genetic Variation Database (HGVD) cohort (n=1208) by chi-square test or Fisher's exact test. Results: In total, 113 variants (28 nonsynonymous, 19 synonymous, 56 intronic, 8 untranslated regions, and 2 deletions) were detected. We could not detect any nonsynonymous variations, insertion or deletion in IKZF1. On the other hand, we detected 8 rare variations in TCF3 and 7 of them are found to be deleterious by in silico analysis. Among them, 1 variant, TCF3 p.S514L, was significantly more common in ALL patients (0.26% in patients vs 0% in ExAC, 0.01% in ToMMO and 0% in HGVD, p=0.0017, 0.0115 and 0.0343 respectively). In PAX5, we found 6 rare variations and 3 of them are found to be deleterious by in silico analysis, However, we could not identify a statistically significant difference in frequency among these variants between TCCSG and normal cohorts. On the other hand, a patient who harbored heterozygous PAX5 p.V26G, which had been reported as a somatic mutation in B-ALL, was diagnosed with primary antibody deficiency after treatment of B-ALL. He is receiving immunoglobulin replacement therapy without relapse of ALL for 15 years. Discussion: Our study implied TCF3 p.S514L is associated with ALL development. Besides, we identified a case of heterozygous PAX5 p.V26G variant who exhibited antibody deficiency and B-ALL. These findings suggest those rare variants impair the normal B-cell development and may predispose to ALL development. GWAS is effective in evaluating common genetic variants. However, it is hard to identify the genes involved Mendelian inheritance or functionally defective rare variants associated with disease susceptibility. Although it is rare, our study suggests that rare variants of genes involved in B cell development could be associated with ALL susceptibility and immunodeficiency, and we revealed the frequency of functionally defective rare variants in Japanese childhood ALL cohort. Disclosures No relevant conflicts of interest to declare.

Abstract B23: Detection of susceptibility to childhood Acute Lymphoblastic Leukemia (ALL)

Abstract Currently, there are no known methods to predict of susceptibility to, and means for prevent Acute Lymphoblastic Leukemia (ALL). We have evaluated and patented a group of proteins dubbed Protein X from a certain strain of Aspergillus Flavus (AF) and developed methods for screening and identifying totally asymptomatic patients in remission of ALL, including long term survivors of this disease, distinguishing them from normal controls. Subject to institutional approved consents/assents, 15-20 ml of blood was obtained from 40 cases of ALL in children and young adults, including long term survivors of ALL. Controls were normal individuals, sickle cell patients undergoing partial exchange transfusion and patients with solid tumors. Mononuclear leukocytes (MNL) of ALL patients in remission and controls were separated using Ficoll Paque Plus (GE Healthcare). Epstein Barr virus (EBV) was obtained commercially. Positive and negative controls for Protein X were aflatoxin and Mycocladus Corymbifera (MC). Avian leukosis virus (ALV) was used as control for EBV. MNL were co-incubated with Protein X ± EBV ± irradiation, for periods of 1-72 hours. Controls were treated identically with appropriate substitutions. Test and control MNLs were examined for genetic markers, NF-κB and cell surface markers (CSM) including CD10/CD19, CD34/CD19, and CD34/CD117. Changes were expressed as percentage of control. Using ELISA, plasmas were tested for antibodies against Protein X ± EBV time experiments reveled 72 hours was optimum for achieving results. Upon 72 hours exposure of MNL from ALL to Protein X ± EBV, cells from ALL patents in remission developed cell surface phenotypes typical of ALL. This was not seen in controls. Addition of EBV ± radiation to Protein X, enhanced these effects in MNL of ALL and not controls. Changes were statistically significant and clearly separated ALL from controls. Evaluation of NF-κB revealed enhancement in ALL and not controls. Aflatoxin indiscriminately induced cell surface marker changes in both, normal and ALL, while ALV and supernatant of MC had no effect. ELISA, using Protein X ± EBV, distinguished ALL from controls. Gene array and biomarkers confirmed transformation to leukemic cell markers upon exposure to Protein X in cells from ALL patients but not controls. These studies reveal, in vitro, upon exposure to Protein X, unlike normal controls, MNL from ALL patients in remission develop cell surface phenotypes and genetic markers typical of ALL. These techniques have potential for screening for ALL and may have implications for etiology of ALL and its prevention. Citation Format: Cameron K. Tebbi. Detection of susceptibility to childhood Acute Lymphoblastic Leukemia (ALL). [abstract]. In: Proceedings of the AACR Special Conference: Improving Cancer Risk Prediction for Prevention and Early Detection; Nov 16-19, 2016; Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(5 Suppl):Abstract nr B23.

Prognostic Impact of Cytogenetic Abnormalities in Adult Patients with Philadelphia-Chromosome (Ph)-Negative Acute Lymphoblastic Leukemia (ALL) Who Underwent Allogeneic Stem Cell Transplant (allo-SCT)

Background: Cytogenetic abnormalities at diagnosis are recognized as a potent prognostic factor for acute leukemia patients. Among acute myeloid leukemia patients, the prognostic implications of cytogenetic abnormalities have been established for those treated with chemotherapy as well as those undergoing allo-SCT. In the context of Ph-negative ALLpatients, cytogenetic abnormalities at diagnosis clearly stratify the prognosis, whereas it has not been elucidated whether similar prognostic stratification is applicable to allo-SCT recipients.Objective: The aim of this retrospective study was to assess the prognostic impact of cytogenetic abnormalities in adult Ph-negative ALL patients who underwent allo-SCT.Patients and Methods: The study cohort included 373 adult Ph-negative ALL patients aged over 15 years who underwent allo-SCT for the first time between January 2001 and December 2012 at the 23 institutions participating in the Kanto Study Group for Cell Therapy (KSGCT). Patients' clinical data were collected from the KSGCT database. The Institutional Review Board of Gunma University approved the protocol of this study. Karyotypes considered high risk (HR) included t(4;11), t(8;14), low hypodiploidy, and complex (equal or more than five abnormalities), and all other karyotypes were designated standard risk (SR). On this basis, 308 patients (82.6%) were categorized as SR and 65 patients (17.4%) were categorized as HR at diagnosis. Of the 373 patients, 267 underwent allo-SCT in complete remission (CR) (224 in the SR group and 43 in HR group), and 106 in non-CR (84 in the SR group and 22 in HR group). For analysis, the study population was stratified based on disease status at the time of transplant. Almost all patients were conditioned with total body irradiation (TBI)-containing myeloablative conditioning (MAC) regimens prior to transplantation. Overall survival (OS) was defined as the interval from the date of transplantation to the date of death. Non-relapse mortality (NRM) was defined as any death in continuous complete remission (CR). The Fisher's exact test was used for comparison of binary variables. OS and RFS were estimated by the Kaplan-Meier method, and compared using the log-rank test. Cumulative incidences (CI) of relapse and NRM were compared using the stratified Gray test. P < 0.05 was considered as statistically significant.Results:[Patients in CR] No significant difference in patient characteristics and transplant procedures was observed between the SR and HR groups. The 5-year OS rates were similar between the SR and HR groups (60.5% vs. 74.1%, respectively; p = 0.225) (Figure 1). Similarly, there were no significant differences in the 5-year CI of relapse and NRM rates between the two groups (relapse: 26.3% vs. 24.8%, respectively; p = 0.498, NRM: 19.6% vs. 10.0%, respectively; p = 0.232). Multivariate analysis for OS identified MAC and TBI-containing regimens, not cytogenetic risk, as significant positive prognostic factors.[Patients in non-CR] No significant difference was observed between the SR and HR groups in terms of patient characteristics or transplant procedures, although there was a female predominance in the HR group. Patients in the SR group had a significantly superior 5-year OS rate compared to the HR group (15.4% vs. 4.5%, respectively; p = 0.022). There was no significant difference in the 5-year CI of relapse between the SR and HR groups (60.3% vs. 50.0%, respectively; p = 0.411), whereas the 5-year CI of NRM in the SR group was significantly lower than that in the HR group (24.8% vs. 45.5%, respectively; p = 0.024). Multivariate analysis revealed cytogenetic risk group as an independent prognostic factor.Conclusion: These findings suggest that adult Ph-negative ALL patients in remission with HR cytogenetic abnormalities have similar transplant outcomes to those in the SR group. Considering the reported equality of the CR rates between the two groups, allo-SCT at an early clinical phase is recommended for HR group patients, reminiscent of Ph-positive ALL patients in the pre-imatinib era. Current transplant procedures do not improve outcomes for patients who are not in remission, especially those with HR cytogenetic abnormalities. DisclosuresUsuki:MSD: Other: personal fees, Research Funding; SymBio Pharmaceutical: Other: personal fees, Research Funding; GlaxoSmithKline: Other: personal fees, Research Funding; Shionogi: Other: personal fees; Fujimoto Pharmaceutical: Research Funding; Bristol-Myers Squibb: Other; Takeda Pharmaceutical: Research Funding; Nippon Shinyaku: Other: personal fees, Research Funding; Sanofi: Other: personal fees, Research Funding; Shire: Research Funding; Kyowa Hakko Kirin: Other: personal fees, Research Funding; Otsuka Pharmaceutical: Research Funding; Eisai: Research Funding; Novartis: Other: personal fees, Research Funding; Boehringer Ingelheim: Other: personal fees, Research Funding; Celgene: Other: personal fees, Research Funding; Sumitomo Dainippon Pharma: Other: personal fees, Research Funding; Chugai Pharmaceutical: Other: personal fees; Fuji Film RI Pharma: Other: personal fees; Taiho Pharmaceutical: Other: personal fees, Research Funding; Astellas: Research Funding. Nakaseko:Novartis: Honoraria, Research Funding, Speakers Bureau; BMS: Honoraria, Research Funding, Speakers Bureau; Pfizer: Honoraria, Research Funding, Speakers Bureau; Otsuka: Honoraria, Research Funding.