The ongoing pandemic Coronavirus Disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a matter of global concern in terms of public health Within the symptoms secondary to SARS-CoV-2 infection, hyposmia and anosmia have emerged as characteristic symptoms during the onset of the pandemic. Although many researchers have investigated the etiopathogenesis of this phenomenon, the main cause is not clear. The appearance of the new variant of concern Omicron has meant a breakthrough in the chronology of this pandemic, presenting greater transmissibility and less severity, according to the first reports. We have been impressed by the decrease in anosmia reported with this new variant and in patients reinfected or who had received vaccination before becoming infected. Based on the literature published to date, this review proposes different hypotheses to explain this possible lesser affectation of smell. On the one hand, modifications in the SARS-CoV-2 spike protein could produce changes in cell tropism and interaction with proteins that promote virus uptake (ACE-2, TMPRSS2, and TMEM16F). These proteins can be found in the sustentacular cells and glandular cells of the olfactory epithelium. Second, due to the characteristics of the virus or previous immunity (infection or vaccination), there could be less systemic or local inflammation that would generate less cell damage in the olfactory epithelium and/or in the central nervous system.

Myelodysplastic syndrome and acute myeloid leukemia (AML) belong to a continuous disease spectrum of myeloid malignancies with poor prognosis in the relapsed/refractory setting necessitating novel therapies. Natural killer (NK) cells from patients with myeloid malignancies display global dysfunction with impaired killing capacity, altered metabolism, and an exhausted phenotype at the single-cell transcriptomic and proteomic levels. In this study, we identified that this dysfunction was mediated through a cross-talk between NK cells and myeloid blasts necessitating cell-cell contact. NK cell dysfunction could be prevented by targeting the αvβ-integrin/TGF-β/SMAD pathway but, once established, was persistent because of profound epigenetic reprogramming. We identified BATF as a core transcription factor and the main mediator of this NK cell dysfunction in AML. Mechanistically, we found that BATF was directly regulated and induced by SMAD2/3 and, in turn, bound to key genes related to NK cell exhaustion, such as HAVCR2 , LAG3 , TIGIT , and CTLA4 . BATF deletion enhanced NK cell function against AML in vitro and in vivo. Collectively, our findings reveal a previously unidentified mechanism of NK immune evasion in AML manifested by epigenetic rewiring and inactivation of NK cells by myeloid blasts. This work highlights the importance of using healthy allogeneic NK cells as an adoptive cell therapy to treat patients with myeloid malignancies combined with strategies aimed at preventing the dysfunction by targeting the TGF-β pathway or BATF.

The sideroblastic anemias are a heterogeneous group of inherited and acquired disorders characterized by anemia and the presence of ring sideroblasts in the bone marrow. Ring sideroblasts are abnormal erythroblasts with iron-loaded mitochondria that are visualized by Prussian blue staining as a perinuclear ring of green-blue granules. The mechanisms that lead to the ring sideroblast formation are heterogeneous, but in all of them, there is an abnormal deposition of iron in the mitochondria of erythroblasts. Congenital sideroblastic anemias include nonsyndromic and syndromic disorders. Acquired sideroblastic anemias include conditions that range from clonal disorders (myeloid neoplasms as myelodysplastic syndromes and myelodysplastic/myeloproliferative neoplasms with ring sideroblasts) to toxic or metabolic reversible sideroblastic anemia. In the last 30 years, due to the advances in genomic techniques, a deep knowledge of the pathophysiological mechanisms has been accomplished and the bases for possible targeted treatments have been established. The distinction between the different forms of sideroblastic anemia is based on the study of the characteristics of the anemia, age of diagnosis, clinical manifestations, and the performance of laboratory analysis involving genetic testing in many cases. This review focuses on the differential diagnosis of acquired disorders associated with ring sideroblasts.

Patients with oligomonocytic chronic myelomonocytic leukemia (OM-CMML) are currently classified according to the 2017 World Health Organization myelodysplastic syndromes classification. However, recent data support considering OM-CMML as a specific subtype of chronic myelomonocytic leukemia (CMML), given their similar clinical, genomic, and immunophenotypic profiles. The main purpose of our study was to provide survival outcome data of a well-annotated series of 42 patients with OM-CMML and to compare them to 162 patients with CMML, 120 with dysplastic type (D-CMML), and 42 with proliferative type (P-CMML). OM-CMML had significantly longer overall survival (OS) and acute myeloid leukemia–free survival than did patients with CMML, considered as a whole group, and when compared with D-CMML and P-CMML. Moreover, gene mutations associated with increased proliferation (ie, ASXL1 and RAS-pathway mutations) were identified as independent adverse prognostic factors for OS in our series. We found that at a median follow-up of 53.47 months, 29.3% of our patients with OM-CMML progressed to D-CMML, and at a median follow-up of 46.03 months, 28.6% of our D-CMML group progressed to P-CMML. These data support the existence of an evolutionary continuum of OM-CMML, D-CMML, and P-CMML. In this context, we observed that harboring more than 3 mutated genes, carrying ASXL1 mutations, and a peripheral blood monocyte percentage >20% significantly predicted a shorter time of progression of OM-CMML into overt CMML. These variables were also detected as independent adverse prognostic factors for OS in OM-CMML. These data support the consideration of OM-CMML as the first evolutionary stage within the proliferative continuum of CMML.

Multiple myeloma (MM) arises following malignant proliferation of plasma cells in the bone marrow, that secrete high amounts of specific monoclonal immunoglobulins or light chains, resulting in the massive production of unfolded or misfolded proteins. Autophagy can have a dual role in tumorigenesis, by eliminating these abnormal proteins to avoid cancer development, but also ensuring MM cell survival and promoting resistance to treatments. To date no studies have determined the impact of genetic variation in autophagy-related genes on MM risk. We performed meta-analysis of germline genetic data on 234 autophagy-related genes from three independent study populations including 13,387 subjects of European ancestry (6863 MM patients and 6524 controls) and examined correlations of statistically significant single nucleotide polymorphisms (SNPs; p < 1 × 10⁻⁹) with immune responses in whole blood, peripheral blood mononuclear cells (PBMCs), and monocyte-derived macrophages (MDM) from a large population of healthy donors from the Human Functional Genomic Project (HFGP). We identified SNPs in six loci, CD46, IKBKE, PARK2, ULK4, ATG5, and CDKN2A associated with MM risk (p = 4.47 × 10⁻⁴−5.79 × 10⁻¹⁴). Mechanistically, we found that the ULK4_rs6599175 SNP correlated with circulating concentrations of vitamin D3 (p = 4.0 × 10⁻⁴), whereas the IKBKE_rs17433804 SNP correlated with the number of transitional CD24⁺CD38⁺ B cells (p = 4.8 × 10⁻⁴) and circulating serum concentrations of Monocyte Chemoattractant Protein (MCP)-2 (p = 3.6 × 10⁻⁴). We also found that the CD46_rs1142469 SNP correlated with numbers of CD19⁺ B cells, CD19⁺CD3⁻ B cells, CD5⁺IgD⁻ cells, IgM⁻ cells, IgD⁻IgM⁻ cells, and CD4⁻CD8⁻ PBMCs (p = 4.9 × 10⁻⁴−8.6 × 10⁻⁴) and circulating concentrations of interleukin (IL)-20 (p = 0.00082). Finally, we observed that the CDKN2A_rs2811710 SNP correlated with levels of CD4⁺EMCD45RO⁺CD27⁻ cells (p = 9.3 × 10⁻⁴). These results suggest that genetic variants within these six loci influence MM risk through the modulation of specific subsets of immune cells, as well as vitamin D3⁻, MCP-2⁻, and IL20-dependent pathways.

Several clinical risk models have been proposed to predict the outcome of follicular lymphoma (FL). The development of next-generation sequencing technologies has allowed the integration of somatic gene mutations into clinical scores to build genotyped-based risk models, such as the m7–Follicular Lymphoma International Prognostic Index (FLIPI). We explored 4 clinical or clinicogenetic-risk models in patients with symptomatic FL who received frontline immunochemotherapy. Of 191 patients with FL grades 1 to 3a, 109 were successfully genotyped. The treatment consisted of rituximab (R) plus cyclophosphamide, vincristine, and prednisone (R-CVP)/cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) (72.5%) or R-bendamustine (R-B) (27.5%). The proportion of cases classified as high risk for FLIPI, FLIPI-2, PRIMA–prognostic index, or m7-FLIPI were 39.3%, 14%, 30.3%, and 22%, respectively. No case with low-intermediate FLIPI was upgraded in the m7-FLIPI, but 18 of the 42 high-risk patients with FLIPI were downgraded to low-risk m7-FLIPI. The sensitivity and specificity for the prediction of POD24 were highest for FLIPI. The discrimination between progression-free survival (PFS) and overall survival (OS) was the best for FLIPI (c-index: 0.644 and 0.727, respectively). When analyzed only in patients treated with R-B, m7-FLIPI showed a higher discrimination between PFS and OS. Thus, the FLIPI remains the clinical risk score with higher discrimination in patients with advanced FL treated with immunochemotherapy; however, the performance of the m7-FLIPI should be further investigated in patients treated with R-B.