Clinical characteristics and evolution of hematological patients and COVID-19 in Argentina: a report from the Argentine Society of Hematology.

Individuals with malignancies and COVID-19 have a lower survival compared with the general population. However, the information about the impact of COVID-19 on the whole hematological population is scarce. We aimed to describe the 30th day overall survival (OS) after COVID-19 infection in patients with a hematological disease in Argentina. A completely anonymous survey from the Argentine Society of Hematology was delivered to all the hematologists in Argentina; it started in April 2020. A cut-off to analyze the data was performed in December 2020 and, finally, 419 patients were reported and suitable for the analysis (average age: 58 years, 90% with malignant diseases). After the COVID-19 diagnosis, the 30-day OS for the whole population was 80.2%. From the entire group (419), 101 (24.1%) individuals required intensive care unit admission, where the 30-day OS was 46.6%. Among allogeneic stem cell transplant recipients, the 30-day OS was 70.3%. Factors associated with a low OS were two or more comorbidities, an active hematological disease and history of chemotherapy. In individuals with the three factors, the 30-day OS was 49.6% while the 30-day OS in those without those factors was 100%. Patients with hematological diseases have a higher mortality than the general population. This group represents a challenge and requires careful decision-making of the treatment in order not to compromise the chances of cure.

El presente estudio tuvo por objetivo primario conocer la mortalidad de pacientes con enfermedad hematológica que presentaron infección por COVID-19 en Argentina. Para ello se difundió una encuesta desde la Sociedad Argentina de Hematología (SAH) entre los hematológos para informar sobre los pacientes con enfermedades hematológicas y diagnóstico de infección por SARS- CoV-2, entre el 19/4/2020, y el 7/12/2020. Se incluyeron individuos de todas las edades con diagnóstico de enfermedad hematológica benigna o maligna e infección por SARS-CoV-2 confirmada por técnica de RTPCR. Se analizaron 419 pacientes (mediana 58 años; 90% enfermedades malignas). La supervivencia al día 30 fue de 80.2%. La supervivencia fue menor en aquellos que requirieron internación (74.2%), cuidados intensivos (46.6%) y asistencia respiratoria mecánica (36.8%). Entre los trasplantados alogénicos la supervivencia fue 70.3%. Los factores vinculados a la supervivencia global fueron las comorbilidades, el estado de la enfermedad al momento de la infección y el antecedente de quimioterapia. Se pudo establecer un score en el que aquellos que tuvieron un puntaje de 4 alcanzaron una supervivencia del 49.6% al día 30, mientras que la de los pacientes con score 0 fue del 100% a 30 días. En comparación con la población general, los pacientes con enfermedades hematológicas presentan una mayor mortalidad vinculada al COVID-19, motivo por el cual es primordial definir pautas destinadas a disminuir la exposición de los mismos sin comprometer las posibilidades de beneficiarse del tratamiento de la enfermedad de base.

Clinical characteristics and evolution of hematological patients and COVID-19 in Argentina: a report from the Argentine Society of Hematology / Características clínicas y evolución de pacientes hematológicos y COVID-19 en Argentina: datos de la Sociedad Argentina de Hematología

Abstract Individuals with malignancies and COVID-19 have a lower survival compared with the general population. However, the information about the impact of COVID-19 on the whole hematological population is scarce. We aimed to describe the 30th day overall survival (OS) after COVID-19 infection in pa tients with a hematological disease in Argentina. A completely anonymous survey from the Argentine Society of Hematology was delivered to all the hematologists in Argentina; it started in April 2020. A cut-off to analyze the data was performed in December 2020 and, finally, 419 patients were reported and suitable for the analysis (average age: 58 years, 90% with malignant diseases). After the COVID-19 diagnosis, the 30-day OS for the whole population was 80.2%. From the entire group (419), 101 (24.1%) individuals required intensive care unit admission, where the 30-day OS was 46.6%. Among allogeneic stem cell transplant recipients, the 30-day OS was 70.3%. Factors associated with a low OS were two or more comorbidities, an active hematological disease and history of chemotherapy. In individuals with the three factors, the 30-day OS was 49.6% while the 30-day OS in those without those factors was 100%. Patients with hematological diseases have a higher mortality than the general population. This group represents a challenge and requires careful decision-making of the treatment in order not to compromise the chances of cure.

Resumen El presente estudio tuvo por objetivo primario conocer la mortalidad de pacientes con enfermedad hematológica que presentaron infección por COVID-19 en Argentina. Para ello se difundió una encuesta desde la Sociedad Argentina de Hematología (SAH) entre los hematológos para informar sobre los pacientes con enfermedades hematológicas y diagnóstico de infección por SARS- CoV-2, entre el 19/4/2020, y el 7/12/2020. Se incluyeron individuos de todas las edades con diagnóstico de enfermedad hematológica benigna o maligna e infección por SARS-CoV-2 confirmada por técnica de RT-PCR. Se analizaron 419 pacientes (mediana 58 años; 90% enfermedades malignas). La supervivencia al día 30 fue de 80.2%. La supervivencia fue menor en aquellos que requirieron internación (74.2%), cuidados intensivos (46.6%) y asistencia respiratoria mecánica (36.8%). Entre los trasplantados alogénicos la supervivencia fue 70.3%. Los factores vinculados a la supervivencia global fueron las comorbilidades, el estado de la enfermedad al momento de la infección y el antecedente de quimioterapia. Se pudo establecer un score en el que aquellos que tuvieron un puntaje de 4 alcanzaron una supervivencia del 49.6% al día 30, mientras que la de los pacientes con score 0 fue del 100% a 30 días. En comparación con la población general, los pacientes con enfermedades hematológicas presentan una mayor mortalidad vinculada al COVID-19, motivo por el cual es primordial definir pautas destinadas a disminuir la exposición de los mismos sin comprometer las posibilidades de beneficiarse del tratamiento de la enfermedad de base.

miRNome profiling of LSC-enriched CD34+CD38-CD26+ fraction in Ph+ CML-CP samples from Argentinean patients: a potential new pharmacogenomic tool.

Chronic myeloid leukemia (CML) is a myeloid stem cell neoplasm characterized by an expansion of myeloid progenitor cells and the presence of BCR-ABL1 oncoprotein. Since the introduction of specific BCR-ABL1 tyrosine kinase inhibitors (TKI), overall survival has improved significantly. However, under long-term therapy patients may have residual disease that originates from TKI-resistant leukemic stem cells (LSC). In this work, we analyzed the miRNome of LSC-enriched CD34+CD38-CD26+ and normal hematopoietic stem cells (HSC) fractions obtained from the same chronic phase (CP) CML patients, and stem and progenitor cells obtained from healthy donors (HD) by next-generation sequencing. We detected a global decrease of microRNA levels in LSC-enriched CD34+CD38-CD26+ and HSC fractions from CML-CP patients, and decreased levels of microRNAs and snoRNAs from a genomic cluster in chromosome 14, suggesting a mechanism of silencing of multiple non-coding RNAs. Surprisingly, HSC from CML-CP patients, despite the absence of BCR-ABL1 expression, showed an altered miRNome. We confirmed by RT-qPCR that the levels of miR-196a-5p were increased more than nine-fold in CD26+ (BCR-ABL1 + ) vs. CD26- (BCR-ABL1 -) CD34+CD38- fractions from CML-CP patients at diagnosis, and in silico analysis revealed a significant association to lipid metabolism and hematopoiesis functions. In the light of recent descriptions of increased oxidative metabolism in CML LSC-enriched fractions, these results serve as a guide for future functional studies that evaluate the role of microRNAs in this process. Metabolic vulnerabilities in LSCs open the road for new therapeutic strategies. This is the first report of the miRNome of CML-CP CD34+CD38- fractions that distinguishes between CD26+ (BCR-ABL1 + ) and their CD26- (BCR-ABL1 - ) counterparts, providing valuable data for future studies.

Evaluation of the primitive fraction by functional in vitro assays at the RNA and DNA level represents a novel tool for complementing molecular monitoring in chronic myeloid leukemia.

Quantification of BCR-ABL1 mRNA levels in peripheral blood of chronic myeloid leukemia patients is a strong indicator of response to tyrosine-kinase inhibitors (TKI) treatment. However, additional prognostic markers are needed in order to better classify patients. The hypothesis of leukemic stem cells (LSCs) heterogeneity and persistence, suggests that their functional evaluation could be of clinical interest. In this work, we assessed the primitive and progenitor fractions in patients at diagnosis and during TKI treatment using functional in vitro assays, defining a "functional leukemic burden" (FLB). We observed that the FLB was reduced in vivo in both fractions upon treatment. However, different FLB levels were observed among patients according to their response to treatment, suggesting that quantification of the FLB could complement early molecular monitoring. Given that FLB assessment is limited by BCR-ABL1 mRNA expression levels, we developed a novel detection method of primitive cells at the DNA level, using patient-specific primers and direct nested PCR in colonies obtained from functional in vitro assays. We believe that this method could be useful in the context of discontinuation trials, given that it is unknown whether the persistent leukemic clone represents LSCs, able to resume the leukemia upon TKI removal.

Revisiting the role of interleukin-8 in chronic lymphocytic leukemia.

The proliferation and survival of malignant B cells in chronic lymphocytic leukemia (CLL) depend on signals from the microenvironment in lymphoid tissues. Among a plethora of soluble factors, IL-8 has been considered one of the most relevant to support CLL B cell progression in an autocrine fashion, even though the expression of IL-8 receptors, CXCR1 and CXCR2, on leukemic B cells has not been reported. Here we show that circulating CLL B cells neither express CXCR1 or CXCR2 nor they respond to exogenous IL-8 when cultured in vitro alone or in the presence of monocytes/nurse-like cells. By intracellular staining and ELISA we show that highly purified CLL B cells do not produce IL-8 spontaneously or upon activation through the B cell receptor. By contrast, we found that a minor proportion (<0.5%) of contaminating monocytes in enriched suspensions of leukemic cells might be the actual source of IL-8 due to their strong capacity to release this cytokine. Altogether our results indicate that CLL B cells are not able to secrete or respond to IL-8 and highlight the importance of methodological details in in vitro experiments.