Flow cytometry immunophenotyping for diagnostic orientation and classification of pediatric cancer based on the euroflow solid tumor orientation tube (Stot)

© 2021 by the authors.Early diagnosis of pediatric cancer is key for adequate patient management and improved outcome. Although multiparameter flow cytometry (MFC) has proven of great utility in the diagnosis and classification of hematologic malignancies, its application to non-hematopoietic pediatric tumors remains limited. Here we designed and prospectively validated a new single eight-color antibody combination—solid tumor orientation tube, STOT—for diagnostic screening of pediatric cancer by MFC. A total of 476 samples (139 tumor mass, 138 bone marrow, 86 lymph node, 58 peripheral blood, and 55 other body fluid samples) from 296 patients with diagnostic suspicion of pediatric cancer were analyzed by MFC vs. conventional diagnostic procedures. STOT was designed after several design–test–evaluate–redesign cycles based on a large panel of monoclonal antibody combinations tested on 301 samples. In its final version, STOT consists of a single 8-color/12-marker antibody combination (CD99-CD8/numyogenin/CD4-EpCAM/CD56/GD2/smCD3-CD19/cyCD3-CD271/CD45). Prospective validation of STOT in 149 samples showed concordant results with the patient WHO/ICCC-3 diagnosis in 138/149 cases (92.6%). These included: 63/63 (100%) reactive/disease-free samples, 43/44 (98%) malignant and 4/4 (100%) benign non-hematopoietic tumors together with 28/38 (74%) leukemia/lymphoma cases; the only exception was Hodgkin lymphoma that required additional markers to be stained. In addition, STOT allowed accurate discrimination among the four most common subtypes of malignant CD45− CD56++ non-hematopoietic solid tumors: 13/13 (GD2++ numyogenin− CD271−/+ nuMyoD1− CD99− EpCAM−) neuroblastoma samples, 5/5 (GD2− numyogenin++ CD271++ nuMyoD1++ CD99−/+ EpCAM−) rhabdomyosarcomas, 2/2 (GD2−/+ numyogenin− CD271+ nuMyoD1− CD99+ EpCAM−) Ewing sarcoma family of tumors, and 7/7 (GD2− numyogenin− CD271+ nuMyoD1− CD99− EpCAM+) Wilms tumors. In summary, here we designed and validated a new standardized antibody combination and MFC assay for diagnostic screening of pediatric solid tumors that might contribute to fast and accurate diagnostic orientation and classification of pediatric cancer in routine clinical practice.This research was funded by the EuroFlow Consortium; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, Brazil (FAPERJ), numbers: E26/110.105/2014, E-26/010.101259/2018, and E26/102.191/2013; grant from Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brasília, Brazil (CNPQ), Brasília, Brazil, numbers: 303765/2018-6, 409440/2016-7, and 400194/2014-7; and Instituto Desiderata/Chevron, Rio de Janeiro, Brazil, grant “Actions to improve pediatric cancer assistance in RJ”; the EuroFlow Consortium (grant LSHB-CT-2006-018708); Centro de Investigación Biomédica en Red de Cáncer (CIBER-ONC; Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain and FONDOS FEDER), numbers: CB16/12/00400, CB16/12/00233, CB16/12/00369, CB16/12/00489 and CB16/12/00480; grant from Bilateral Cooperation Program between Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-CAPES (Brasília/Brazil) and Dirección General de Políticas Universitárias (DGPU)-Ministério de Educación, Cultura y Deportes (Madrid/Spain) number DGPU 311/15

High frequency of low-count monoclonal B-cell lymphocytosis in hospitalized COVID-19 patients

Low-count monoclonal B-cell lymphocytosis (MBLlo, <500 clonal B-cells/μL) is a highly prevalent condition in the general population (4% to 16% of otherwise healthy adults), which increases significantly with age.1-7 In most cases, clonal B-cells share phenotypic and cytogenetic features with chronic lymphocytic leukemia (CLL), but only a small fraction (≈1.8%) progresses to high-count MBL (MBLhi; ≥500 and <5000 clonal B-cells/μL)3 in the medium-term.8 However, previous reports showed that MBLlo subjects had an increased risk of severe infections in association with a (predominantly) secondary antibody deficiency,8-10 suggesting that MBLlo might be a risk marker for developing more severe infections.This work was supported by the Instituto de Salud Carlos III (Ministerio de Ciencia e Innovación, Madrid, Spain, and FONDOS FEDER (a way to build Europe) grants CB16/12/00400 (CIBERONC), COV20/00386, and PI17/00399; the Consejería de Educación and the Gerencia Regional de Salud, Consejería de Sanidad from Junta de Castilla y León (Valladolid, Spain) grants SA109P20 and GRS-COVID-33/A/20; the European Regional Development Fund (INTERREG POCTEP Spain-Portugal) grant 0639-IDIAL-NET-3-3; and the CRUK (United Kingdom), Fundación AECC (Spain), and Associazione Italiana per la Ricerca Sul Cancro (Italy) “Early Cancer Research Initiative Network on MBL (ECRINM3)” ACCELERATOR award. G.O.-A. is supported by a grant from the Consejería de Educación, Junta de Castilla y León (Valladolid, Spain); B.F.-H. was supported by grant 0639-IDIAL-NET-3-3.Peer reviewe

Immunophenotypic shifts during minimal residual evaluation in a case of leukemic form of anaplastic large cell lymphoma ALK+

Abstract Background This study aims to describe immunophenotypic explorations at diagnosis and follow up of a pediatric patient with leukemic phase of ALK+ anaplastic large cell lymphoma (ALCL) by multiparametric flow cytometry (MFC). Case An 8‐color MFC combination of antibodies allowed to identify neoplastic cells in concentrations until 0.02% during minimal residual disease (MRD) monitoring. Immunophenotypic shifts occurred in key markers as CD30, CD7, CD2, and CD5, however neoplastic cells were clearly discriminated from normal populations. Conclusion MFC can be a useful tool for ALCL diagnosis and MRD monitoring and may support therapeutic decisions

Immunophenotypic identification and chraracterization of pediatric tumor samples.

<p>In panel A, an illustrating example of the gating strategy and bivariate dot plot combinations used for the identification of CD45− tumor cells, CD45− residual stromal cells (e.g. endothelial cells and mesenquimal cells) and infiltrating hematopoietic cells (e.g. neutrophils, B and T cells) is shown. In turn, in panels B to J the immunophenotypic profile of CD45− tumor cells from a neuroblastoma (panels B and H), a PNET (panels C and I) and a rhabdomyossarcoma (panels D and J) tumor are shown together with representative pictures of the histophathological and immunohistochemical profiles of the same tumors stained with hematoxilin & eosin plus cromogranin (neuroblastoma cells in panel E), CD99 (PNET cells in panel F) and _(nu)myogenin (rhabdomyossarcoma cells in panel G).</p

Pattern of antigen expression by tumor cells from different diagnostic categories of pediatric solid tumors.

<p>−: negative; +lo :low expression levels/cells; +: positive; +hi: strong expression levels/cells.</p><p>Both CD7 and CD8 were systematically negative in all tumors analyzed.</p>*<p>The only ganglioneuroblastoma tumor analyzed showed a similar profile but it contained two distinct populations which differed on CD56, CD9 and CD81 expression, in the absence of CD117.</p> <p>CD271 was only partially present in one neuroblastoma tumor.</p>§<p>% of positive cells only among positive case.</p