Characterization of CRLF2 Expression in Pediatric B-Cell Precursor Acute Lymphoblastic Leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is a heterogeneous disease with several underlying genetic ab-normalities. Several studies have tried to elucidate the prognostic significance of cytokine receptor-like factor 2 (CRLF2) overexpression in pediatric B-cell precursor (BCP)-ALL; however, it is still controversial. METHODS: CRLF2 expression was assessed by flow cytometry in 87 newly diagnosed BCP-ALL pediatric patients, and 80 age and gender-matched control group. Janus Kinase2 (JAK2) (R683) mutation analysis was also performed in those identified to have CRLF2 overexpression with adequate DNA samples by direct sequencing. RESULTS: CRLF2 overexpression was identified in 26/87 (29.9%) of our patients with cutoff set at mean fluorescence intensity (MFI = 3.8) using the Receiver Operating Characteristic (ROC) curve. There were no significant differences in the clinical and laboratory features between patients with high and low-CRLF2 expression, apart from thrombocytopenia which showed statistically significant association with the low-expression group (p = 0.041). Sequence analysis of samples with high CRLF2 expression (n = 23) revealed that 2/23 (8.7%) cases harbored the mutation JAK2 (R683). CRLF2 levels did not have a significant impact on either overall survival (OS) or disease free survival (DFS) (p = 0.601; p = 0.212, respectively). CONCLUSIONS: CRLF2 overexpression was not an adverse parameter in pediatric BCP-ALL patients. However, patients with CRLF2 overexpression may harbor the JAK2 mutation presenting a group that can benefit from targeted therapy by kinase inhibitors. The usage of CRLF2 expression to monitor minimal residual disease of BCP-ALL would be an area of interest for further evaluation.

Acute lymphoblastic leukemia-like treatment regimen provides better response in mixed phenotype acute leukemia: a comparative study between adults and pediatric MPAL patients.

Mixed phenotype acute leukemia (MPAL) is a rare type of leukemia with a limited number of studies conducted to characterize its clinical spectrum and most importantly the best treatment modality. MPAL blasts show more than one phenotype either myeloid/monocytic with T- or B-lymphoid or extremely rare triple lineage associated phenotypic markers. This study aimed to characterize MPAL cases with special emphasis on comparing adult and pediatric age groups, exploring treatment regimens, and clinical outcome. Among 2571 acute leukemia patients, 102 MPAL cases fulfilling the 2008/2016 WHO diagnostic criteria of MPAL were recruited in the study. The incidence of MPAL was 4% of acute leukemia patients. Pediatric cases were 54 (53%) while adults were 48/102 (47%). Myeloid/B-lymphoid phenotype was found in 86/102 (84%), with BCR-ABL fusion gene transcript detected in 14/102(13.7%) patients. ALL-like treatment showed better response rates as compared with the myeloid based regimen (p = 0.001). MPAL behaves in a manner that resembles in clinical features, their lymphoid progenitor counterpart leukemias both in adults and pediatric patients with superior treatment response to ALL-like regimen, especially in adults.

Duplication 1q is highly correlated with poor prognosis in high hyperdiploid pediatric B-acute lymphoblastic leukemia.

BACKGROUND: The role of structural abnormalities in high hyperdiploidy (HeH) has been debatable, with few studies that addressed recurrent translocations with concurrent HeH (t-HeH). We aimed at the characterization of HeH cases in pediatric B-acute lymphoblastic leukemia (B-ALL) patients with special emphasis on the structural abnormalities including t-HeH. PATIENTS AND METHODS: Our study included all patients diagnosed with HeH over the period from January 2016 to April 2019 presenting to the Pediatric Oncology Department, National Cancer Institute, Cairo University. RESULTS: Among 480 de novo B-ALL pediatric patients, HeH was detected in eighty (16.7%) cases with a median age of 5 years. t-HeH was identified in 17/480 (3.5%) cases: 9(1.9%) with t(12;21), 7(1.5%) with t(9;22), and 1(0.2%) with t(4;11). Duplication (1q) was the most prevalent structural abnormality in c-HeH (hyperdiploidy without recurrent translocations) (n = 12,15%). Children ≥10 years or presenting with white blood cells (WBC) ≥50 × 109 /L) had an inferior 3 year-overall survival as compared to younger children (P = .003), and to lower WBC (P = .02). Duplication (1q) was an independent adverse parameter on the disease-free survival (DFS) of c-HeH patients (P = .004). CONCLUSIONS: Older age and WBC ≥ 50 × 109 /L were adverse prognostic factors. Duplication (1q) is correlated with lower DFS in c-HeH patients. t-HeH has distinct patterns of chromosomal gain.

No prognostic significance of normalized copy number of PML-RARA transcript at diagnosis in patients with acute promyelocytic leukemia.

BACKGROUND: Acute promyelocytic leukemia is a peculiar disease with few studies that have investigated the prognostic significance of PML/RARA transcript level at diagnosis. PATIENTS AND METHODS: This retrospective study included all cases diagnosed with acute promyelocytic leukemia over the period from June 2015 to March 2019. The normalized copy number (NCN) was tested by real-time polymerase chain reaction at diagnosis, and at the end of induction regimen. RESULTS: Our study included 83 de novo APL patients, 53 (63.9%) were adults and 30 (36.1%) were children. The median (range) age of our patients was 28.0 (1.0-70.0) years. The pediatric group had a significantly higher prevalence in males (p = 0.02), higher incidence of disseminated intravascular coagulopathy (p = 0.014), and high-risk groups (p = 0.017). At diagnosis, the median NCN (%) of the entire group at 22.5 was set as the cut off value. There was no significant association between NCN at diagnosis and other prognostic variables except for bone marrow promyelocytes (p = 0.006). High-risk group APL patients as well as those presenting with hemorrhage had an inferior overall survival (OS) (p = 0.007; p < 0.001) respectively. PML-RARA NCN at diagnosis did not have an impact on the OS or increased risk of relapse of our patients (p = 0.434; p = 0.721). CONCLUSION: the initial PML/RARA tumor burden is not a prognostic factor for APL. The initial TLC at 10x109/L cut off is the most important predictive for OS. Early detection and close monitoring are required to decrease the high rate of early deaths in developing countries.

Prognostic Significance of bcr-1 and bcr-3 Isoforms of PML-RARA and FLT3-ITD in Patients With Acute Promyelocytic Leukemia.

BACKGROUND: Acute promyelocytic leukemia (APL) has a characteristic peculiar morphologic and genetic features as well as a more favorable outcome. We studied the differential effect of bcr-1 and bcr-3 isoforms of the promyelocytic leukemia/retinoic acid receptor alpha (PML-RARA) transcript together with FLT3 internal tandem duplication (FLT3-ITD) mutation status on the outcome of newly diagnosed de novo APL patients. PATIENTS AND METHODS: This cohort study included all patients diagnosed with APL at outpatient medical and pediatric oncology clinics of the National Cancer Institute, Cairo University, Cairo, Egypt, from May 2012 to January 2018. RESULTS: The study included 118 patients with APL, 71 adults (60.2%) and 47 children (39.8%). Median (range) age was 25 (1.5-70) years. Children had significantly higher total leukocyte count (≥10 × 109/L), disseminated intravascular coagulation (DIC), and thrombocytopenia (< 40 × 109/L) than adults (P = .04, .03, and .04, respectively), while the latter group had significantly higher hemorrhage than children (P = .04). FLT3-ITD mutation was detected in the whole group, children, and adults in 23.7%, 30.6%, and 24.6%, respectively. FLT3-ITD mutation was significantly associated with leukocytosis in the whole group (P = .039). bcr-3 was significantly associated with FLT3-ITD mutation in the whole APL cohort and in adults (P = .011, P = .022). All children (both bcr-1 and bcr-3) and all adult patients with bcr-3 experienced CR, while 22 (78.5%) of 28 patients with bcr-1 experienced CR (P = .04). APL patients with DIC and hemorrhage had significantly lower overall survival (P = .002 and < .001, respectively). Overall survival for APL in children was significantly better than in adults (P = .005). Multivariate analysis indicated that age was an independent prognostic variable affecting survival (hazard ratio = 2.6; 95% confidence interval, 1.3-5.3; P = .007) (adults had hazard ratio of death 2.6 times higher than children). DIC and FLT3-ITD were independent prognostic variables affecting survival in children with APL (hazard ratio = 12.3; 95% confidence interval, 1.46-104.61; P = .021; and hazard ratio = 5.2; 95% confidence interval, 1.01-26.95; P = .048, respectively). CONCLUSION: Age is an independent prognostic factor for APL. bcr-3 is significantly associated with FLT3-ITD in adults with APL. DIC and FLT3-ITD are adverse prognostic factors in children with APL. Despite children being at higher risk, outcome is better than in adults.

Variability of contribution of vitamin D receptor gene polymorphisms to outcome of HLA-matched sibling allogeneic bone marrow transplantation.

Graft-versus-host disease (GVHD) remains one of the major complications of hematopoietic stem cell transplantation (HSCT). Several etiological factors were investigated. Among these, vitamin D and hence its receptor (VDR) gene polymorphisms have gained much interest; however, the results are still controversial. Using PCR-RFLP, we genotyped VDR polymorphisms FokI (rs10735810), ApaI (rs7975232), and Taq1 (rs731236) in 80 patient/donor pairs according to DNA availability. No association was encountered between VDR polymorphisms and GVHD. Neither was there any impact on survival. Only grade II-IV acute GVHD was associated with inferior overall (p = .01), but not disease-free survival. The controversy between our results and the literature may be attributed to marked variability in the relative distribution of VDR genotypes in different populations. Also different environmental factors, including exposure to sun, may ensure vitamin D sufficiency nullifying the impact of VDR polymorphisms.