Cytogenetic and pathologic characterization of MYC-rearranged B-cell lymphomas in pediatric and young adult patients.

MYC-rearranged B-cell lymphoma (BCL) in the pediatric/young adult (YA) age group differs substantially in disease composition from adult cohorts. However, data regarding the partner genes, concurrent rearrangements, and ultimate diagnoses in these patients is scarce compared to that in adult cohorts. We aimed to characterize the spectrum of MYC-rearranged (MYC-R) mature, aggressive BCL in the pediatric/YA population. A retrospective study of morphologic, immunophenotypic, and fluorescence in situ hybridization (FISH) results of patients age ≤ 30 years with suspected Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL) or high-grade B-cell lymphoma (HGBCL), and a MYC-R by FISH between 2013-2022 was performed. Two-hundred fifty-eight cases (129 (50%) pediatric (< 18 years) and 129 (50%) YA (18-30 years)) were included. Most MYC-R BCL in pediatric (89%) and YA (66%) cases were BL. While double-hit (DH) cytogenetics (MYC with BCL2 and/or BCL6-R, HGBCL-DH) was rare in the pediatric population (2/129, 2%), HGBCL-DH increased with age and was identified in 17/129 (13%) of YA cases. Most HGBCL-DH had MYC and BCL6-R, while BCL2-R were rare in both groups (3/258, 1%). MYC-R without an IG partner was more common in the YA group (14/116 (12%) vs 2/128 (2%), p = 0.001). The pediatric to YA transition is characterized by decreasing frequency in BL and increasing genetic heterogeneity of MYC-R BCL, with emergence of DH-BCL with MYC and BCL6-R. FISH to evaluate for BCL2 and BCL6 rearrangements is likely not warranted in the pediatric population but should continue to be applied in YA BCL.

High-grade B-cell lymphoma with a quadruple-hit genetic profile including concurrent MYC, BCL2, BCL6, and CCND1 gene rearrangements.

Several reports of concurrent MYC, BCL2, BCL6, and CCND1 rearrangements in high-grade B-cell lymphoma (HGBL) have been recently described. Herein, we aimed to delineate the scope of this entity through a review of HGBL with a "quadruple-hit" genetic profile identified at our institution. We performed a retrospective review (2015-2023) at our institution of B-cell lymphoma (BCL) cases that were evaluated with concurrent MYC, BCL2, and BCL6 break-apart and IGH::MYC and IGH::CCND1 dual-color dual-fusion fluorescence in situ hybridization studies. Of 203 cases meeting inclusion criteria, 2 (1%) with a quadruple-hit genetic profile were identified. Case 1 represented a 59-year-old female with widespread lymphadenopathy and a diagnosis of HGBL who exhibited primary refractoriness to dose-adjusted etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab (DA-EPOCH-R) chemotherapy. Case 2 represented a 58-year-old male with mediastinal and abdominal lymphadenopathy and a diagnosis of large BCL who died from disease after 1 cycle of DA-EPOCH-R chemotherapy. Similarly, a literature review of 7 previously reported cases of HGBL with a quadruple-hit profile also demonstrated aggressive disease behavior. Our study adds 2 new cases to the rarely encountered quadruple-hit HGBL, and a brief meta-analysis of the 9 available cases indicates aggressive disease behavior conferred by this constellation of genetic events.

Superior detection rate of plasma cell FISH using FACS-FISH.

OBJECTIVES: Fluorescence in situ hybridization (FISH) for plasma cell neoplasms (PCNs) requires plasma cell (PC) identification or purification strategies to optimize results. We compared the efficacy of cytoplasmic immunoglobulin FISH (cIg-FISH) and fluorescence-activated cell sorting FISH (FACS-FISH) in a clinical laboratory setting. METHODS: The FISH analysis results of 14,855 samples from individuals with a suspected PCN subjected to cytogenetic evaluation between 2019 and 2022 with cIg-FISH (n = 6917) or FACS-FISH (n = 7938) testing were analyzed. RESULTS: Fluorescence-activated cell sorting-FISH increased the detection rate of abnormalities in comparison with cIg-FISH, with abnormal results documented in 54% vs 50% of cases, respectively (P < .001). It improved the detection of IGH::CCND1 (P < .001), IGH::MAF (P < .001), IGH::MAFB (P < .001), other IGH rearrangements (P < .001), and gains/amplifications of 1q (P < .001), whereas the detection rates of IGH::FGFR3 fusions (P = .3), loss of 17p (P = .3), and other abnormalities, including hyperdiploidy (P = .5), were similar. Insufficient PC yield for FISH analysis was decreased between cIg-FISH and FACS-FISH (22% and 3% respectively, P < .001). Flow cytometry allowed establishment of ploidy status in 91% of cases. In addition, FACS-FISH decreased analysis times, workload efforts, and operating costs. CONCLUSIONS: Fluorescence-activated cell sorting-FISH is an efficient PC purification strategy that affords significant improvement in diagnostic yield and decreases workflow requirements in comparison with cIg-FISH.

Interplay between hereditary and acquired factors determines the neutrophil counts in older individuals.

Blood cell production is a complex process, partly genetically determined and influenced by acquired factors. However, there is a paucity of data on how these factors interplay in the context of aging, which is associated with a myeloid proliferation bias, clonal hematopoiesis (CH), and an increased incidence of myeloid cancers. We investigated hereditary and acquired factors underlying blood cell trait variability in a cohort of 2996 related and unrelated women from Quebec aged from 55 to 101 years. We performed a genome-wide association study, evaluated the impact of chronic diseases, and performed targeted deep sequencing of CH driver genes and X-chromosome inactivation (XCI)-based clonality analyses. Multivariable analyses were conducted using generalized linear mixed models. We document that aging is associated with increasing neutrophil and monocyte counts and decreasing lymphocyte counts. Neutrophil counts were influenced by the variants in the region of GSDMA and PSMD3-CSF3, but this association decreased with age; in parallel, older individuals with cardiometabolic comorbidities exhibited significantly higher neutrophil counts (4.1 × 109/L vs 3.83 × 109/L; P < .001) than younger individuals. These age-related diseases were also associated with an increase in other myeloid-derived cells. Neither CH nor XCI clonality correlated with neutrophil counts. In conclusion, we show that neutrophil counts are genetically influenced, but as individuals age, this contribution decreases in favor of acquired factors. Aging is associated with a myeloid proliferation bias which is greater in the presence of cardiometabolic comorbidities but not of CH. These findings support that cell-extrinsic factors may contribute to the myeloid shift possibly through low-grade inflammation.

A TRIP11:: FLT3 gene fusion in a patient with myeloid/lymphoid neoplasm with eosinophilia and tyrosine kinase gene fusions: a case report and review of the literature.

Myeloid/lymphoid neoplasms with FLT3 gene fusions have recently been included among myeloid/lymphoid neoplasms with eosinophilia and tyrosine kinase gene fusions (MLN-TK) in the World Health Organization classification and International Consensus Classification. As this entity remains remarkably rare, its scope and phenotypic features are evolving. In this report, we describe a 33-yr-old male with MLN-TK. Conventional chromosome analysis revealed a t(13;14)(q12;q32). Further analysis with mate-pair sequencing (MPseq) confirmed a TRIP11::FLT3 gene fusion. A diagnosis of MLN-TK was rendered. To the best of our knowledge, we report the third case of MLN-TK with a TRIP11::FLT3 gene fusion. In contrast to previously described cases, our case exhibited distinctly mild clinical features and disease behavior, emphasizing the diverse spectrum of MLN-TK at primary presentation and variability in disease course. MLN-TK with FLT3 gene fusions are a genetically defined entity which may be targetable with tyrosine kinase inhibitors with anti-FLT3 activity. Accordingly, from diagnostic and therapeutic viewpoints, genetic testing for FLT3 rearrangements using fluorescence in situ hybridization (FISH) or sequencing-based assays should be pursued for patients with chronic eosinophilia.

Typical, atypical and cryptic t(15;17)(q24;q21) (PML::RARA) observed in acute promyelocytic leukemia: A retrospective review of 831 patients with concurrent chromosome and PML::RARA dual-color dual-fusion FISH studies.

The diagnosis of acute promyelocytic leukemia (APL) relies on the identification of PML::RARA fusion. While the majority of APL cases harbor a typical t(15;17)(q24;q21), atypical genetic mechanisms leading to the oncogenic PML::RARA fusion have been reported yet their frequency and scope remain poorly characterized. We assessed the genetic findings of 831 cases with APL investigated with concurrent chromosome banding analysis and dual-color dual-fusion fluorescence in situ hybridization (D-FISH) analysis at our institution over an 18.5-year timeframe. Seven hundred twenty-three (87%) cases had a typical balanced t(15;17) with both testing modalities. Atypical karyotypic results including complex translocations, unbalanced rearrangements and insertional events occurred in 50 (6%) cases, while 6 (0.7%) cases were cryptic by conventional chromosome studies despite PML::RARA fusion by D-FISH evaluation. Atypical FISH patterns were observed in 48 (6%) cases despite apparently balanced t(15;17) on chromosome banding analysis. Two hundred fifty (30%) cases displayed additional chromosome abnormalities of which trisomy/tetrasomy 8 (37%), del(7q)/add(7q) (12%), and del(9q) (7%) were most frequent. Complex and very complex karyotypes were observed in 81 (10%) and 34 (4%) cases, respectively. In addition, 4 (0.5%) cases presented as an apparently doubled, near-tetraploid stemline clone. This report provides the largest appraisal of cytogenetic findings in APL with conventional chromosome and PML::RARA D-FISH analysis. By characterizing the frequency and breadth of typical and atypical results through the lens of these cytogenetic testing modalities, this study serves as a pragmatic source of information for those involved in the investigation of APL in both the clinical and research laboratory settings.

Identification of EWSR1 rearrangements in patients with immature hematopoietic neoplasms: A case series and review of literature.

Rearrangement of the EWSR1 gene (22q12.2) is a well-recognized genetic lesion in bone and soft tissue tumors. However, few reports have suggested that EWSR1 rearrangements may also occur in the setting of hematopoietic tumors. We herein describe two cases of immature hematopoietic neoplasms presenting with EWSR1 rearrangements. The first occurred in a 41-year-old female diagnosed with mixed-phenotype acute leukemia, B/T/myeloid, in which conventional chromosome analysis revealed a t(2;22)(q35;q12). Further analysis with whole genome sequencing revealed that this rearrangement led to an EWSR1::FEV gene fusion. The second case was identified in an 18-year-old male with a high-grade B-cell lineage malignant neoplasm with immature features in which conventional chromosome analysis revealed a t(17;22)(q25;q12). Mate-pair sequencing, a next generation sequencing-based assay, was performed and revealed three in-frame chimeric gene fusions involving the EWSR1, TEF and STRADA gene regions. This report further expands the repertoire of hematopoietic neoplasms with EWSR1 fusions and partner genes involved in these rearrangements.

The Evolution of Monoclonal Gammopathy of Undetermined Significance in Kidney Transplant Recipients.

It is unclear if immunosuppression increases the likelihood of malignant transformation of monoclonal gammopathy of undetermined significance (MGUS) and whether adverse renal outcomes in kidney transplant recipients with MGUS are more frequent. METHODS: We performed a retrospective cohort study of kidney transplant recipients at the Centre Hospitalier de l'Université de Montréal between 2000 and 2016. RESULTS: Among 755 study participants, 13 (1.7%) were found to have MGUS before transplant. Two evolved to smoldering multiple myeloma and 2 presented paraprotein-induced allograft injury from light chain deposition disease. Forty-six patients developed posttransplant MGUS (2.5% 5-y cumulative incidence) of which 1 progressed to multiple myeloma and 1 experienced kidney allograft loss from light chain deposition disease. None of the patients with a malignant transformation or paraprotein-induced renal disease after transplantation had had a systematic workup before transplantation to exclude hematologic malignancies and paraprotein-related kidney injury. Nine posttransplant MGUS (21%) were transient. Multivariable analysis revealed that age at transplant (hazard ratio 1.05 per 1-y increase, 95% confidence intervals, 1.02-1.08) and prior cytomegalovirus infection (hazard ratio 2.22, 95% confidence intervals, 1.07-4.58) were associated with the development of MGUS after transplantation. Of 7 posttransplant lymphoproliferative disorders, none were preceded by MGUS. CONCLUSIONS: Our results suggest that the identification of MGUS in a transplant candidate should lead to further investigations to exclude a plasma cell neoplasm and monoclonal gammopathy of renal significance before transplantation. MGUS arising after transplantation appears to carry a favorable evolution.

Cartography of emergency department visits for asthma - targeting high-morbidity populations.

BACKGROUND: Asthma education should be offered with priority to populations with the highest asthma-related morbidity. In the present study, the aim was to identify populations with high-morbidity for asthma from the Quebec Health Insurance Board Registry, a large administrative database, to help the Quebec Asthma and Chronic Obstructive Pulmonary Disease Network target its interventions. METHODS: All emergency department (ED) visits for asthma were analyzed over a one-year period, considering individual and medical variables. Age- and sex-adjusted rates, as well as standardized rate ratios related to the overall Quebec rate, among persons zero to four years of age and five to 44 years of age were determined for 15 regions and 163 areas served by Centres Locaux de Services Communautaires (CLSC). The areas with rates 50% to 300% higher (P<0.01) than the provincial rate were defined as high-morbidity areas. Maps of all CLSC areas were generated for the above parameters. RESULTS: There were 102,551 ED visits recorded for asthma, of which more than 40% were revisits. Twenty-one CLSCs and 32 CLSCs were high-morbidity areas for the zero to four years age group and five to 44 years age group, respectively. For the most part, the high-morbidity areas were located in the south-central region of Quebec. Only 47% of asthmatic patients seen in ED had also seen a physician in ambulatory care. CONCLUSION: The data suggest that a significant portion of the population seeking care at the ED is undiagnosed and undertreated. A map of high-morbidity areas that could help target interventions to improve asthma care and outcomes is proposed.

Integrating GIS components with knowledge discovery technology for environmental health decision support.

This paper presents a new category of decision-support tools that builds on today's Geographic Information Systems (GIS) and On-Line Analytical Processing (OLAP) technologies to facilitate Geographic Knowledge Discovery (GKD). This new category, named Spatial OLAP (SOLAP), has been an R&D topic for about 5 years in a few university labs and is now being implemented by early adopters in different fields, including public health where it provides numerous advantages. In this paper, we present an example of a SOLAP application in the field of environmental health: the ICEM-SE project. After having presented this example, we describe the design of this system and explain how it provides fast and easy access to the detailed and aggregated data that are needed for GKD and decision-making in public health. The SOLAP concept is also described and a comparison is made with traditional GIS applications.