A Shift Towards an Immature Myeloid Profile in Peripheral Blood of Critically Ill COVID-19 Patients.

BACKGROUND: SARS-CoV-2, the etiological agent causing COVID-19, has infected more than 27 million people with over 894000 deaths worldwide since its emergence in December 2019. Factors for severe diseases, such as diabetes, hypertension, and obesity have been identified however, the precise pathogenesis is poorly understood. To understand its pathophysiology and to develop effective therapeutic strategies, it is essential to define the prevailing immune cellular subsets. METHODS: We performed whole circulating immune cells scRNAseq from five critically ill COVID-19 patients, trajectory and gene ontology analysis. RESULTS: Immature myeloid populations, such as promyelocytes-myelocytes, metamyelocytes, band neutrophils, monocytoid precursors, and activated monocytes predominated. The trajectory with pseudotime analysis supported the finding of immature cell states. While the gene ontology showed myeloid cell activation in immune response, DNA and RNA processing, defense response to the virus, and response to type 1 interferon. Lymphoid lineage was scarce. Expression of genes such as C/EBPß, IRF1and FOSL2 potentially suggests the induction of trained immunity. CONCLUSIONS: Our results uncover transcriptomic profiles related to immature myeloid lineages and suggest the potential induction of trained immunity.

Increased expression of hypoxia-induced factor 1α mRNA and its related genes in myeloid blood cells from critically ill COVID-19 patients.

BACKGROUND: COVID-19 counts 46 million people infected and killed more than 1.2 million. Hypoxaemia is one of the main clinical manifestations, especially in severe cases. HIF1α is a master transcription factor involved in the cellular response to oxygen levels. The immunopathogenesis of this severe form of COVID-19 is poorly understood. METHODS: We performed scRNAseq from leukocytes from five critically ill COVID-19 patients and characterized the expression of hypoxia-inducible factor1α and its transcriptionally regulated genes. Also performed metanalysis from the publicly available RNAseq data from COVID-19 bronchoalveolar cells. RESULTS: Critically-ill COVID-19 patients show a shift towards an immature myeloid profile in peripheral blood cells, including band neutrophils, immature monocytes, metamyelocytes, monocyte-macrophages, monocytoid precursors, and promyelocytes-myelocytes, together with mature monocytes and segmented neutrophils. May be the result of a physiological response known as emergency myelopoiesis. These cellular subsets and bronchoalveolar cells express HIF1α and their transcriptional targets related to inflammation (CXCL8, CXCR1, CXCR2, and CXCR4); virus sensing, (TLR2 and TLR4); and metabolism (SLC2A3, PFKFB3, PGK1, GAPDH and SOD2). CONCLUSIONS: The up-regulation and participation of HIF1α in events such as inflammation, immunometabolism, and TLR make it a potential molecular marker for COVID-19 severity and, interestingly, could represent a potential target for molecular therapy. Key messages Critically ill COVID-19 patients show emergency myelopoiesis. HIF1α and its transcriptionally regulated genes are expressed in immature myeloid cells which could serve as molecular targets. HIF1α and its transcriptionally regulated genes is also expressed in lung cells from critically ill COVID-19 patients which may partially explain the hypoxia related events.

Utilidad de la relación cobre/zinc en pacientes con linfoma o leucemias aguda o crónica / Serum copper and zinc levels and Cu/Zn ration in lymphoma and acute and chronic leukemia

Objetivo. Conocer si la relación cobre/zinc (cobre elevado, zinc bajo) se encuentra aumentada en pacientes con neoplasias malignas hematológicas comparada con sujetos controles sanos de edad y sexo similares. Metodología. Se estudiaron 44 pacientes con neoplasias hemato-concológicas de reciente diagnóstico, sin tratamiento previo: 17 linfomas (11 no-Hodgkin), 15 con leucemia aguda (10 mieloblásticas) y 12 con leucemia crónica (8 granulocíticas). También se incluyeron 95 sujetos controles sanos. Se utizó un espectrofotómetro de absorción atómica (Perkin Elmer modelo 2380) para la cuantificación de los niveles séricos de cobre y zinc. Resultados. Los niveles séricos de cobre (µg/dL) fueron significativamente menores en los sujetos controles(54.4 ñ 8.9, p< 0.05), en comparación con los pacientes con linfoma (93.7 ñ 37.5), con leucemia aguda (80.6 ñ 44.6) y con leucemia crónica (95.7 ñ 28.9) mientras que los niveles séricos de zinc (µg/dL) resultaron significativamente mayores en sujetos controles (100.4 ñ 14, p< 0.05) en comparación con los pacientes con linfoma (77.2 ñ 22.6), leucemia aguda (66 ñ 15.6) o leucemia crónica (74.8 ñ 14.7). La relación cobre/zinc resultó ser significativamente más baja en sujetos controles (0.54 ñ 0.13, p< 0.05) que en pacientes con linfoma (1.21 ñ 0.5), leucemia aguda (1.22 ñ 0.7) o leucemia crónica (1.28 ñ 0.4). Veintitrés pacientes falleciron durante el seguimiento (media de 13 meses) observándose que sus niveles séricos de zinc fueron significativamente más bajos (68 ñ 28) que en los pacientes que sobrevivieron (76 ñ 15, p< 0.05). Conclusión. La relación sobre/zinc se encuentra significativamente elevada en pacientes con neoplasias malignas hematológicas