Background Etiopathogenesis of the clinical variability of the coronavirus disease 2019 (COVID-19) remains mostly unknown. Here we investigate the role of Killer-cell Immunoglobulin-like receptor (KIR)/Human Leukocyte Antigen Class-I (HLA-I) interactions in the susceptibility and severity of COVID-19. Methods KIR and HLA-I genotyping and NK cell (NKc) receptors immunophenotyping in 201 symptomatic patients and 210 non-infected controls. Results NKcs with a distinctive immunophenotype, suggestive of recent activation (KIR2DS4 low CD16 low CD226 low CD56 high TIGIT high NKG2A high), expanded in patients with severe COVID-19. This was associated with a higher frequency of the functional A-telomeric activating KIR2DS4 in severe than mild/moderate patients and controls (83.7%, 55.7% and 36.2%, p<7.7x10 -9). In mild/moderate patients HLA-B*15:01 was associated with higher frequencies of activating B-telomeric KIR3DS1 compared to patients with other HLA-B*15 subtypes and non-infected controls (90.9%, 42.9% and 47.3%, p<0.002, Pc=0.022). This strongly suggests that HLA-B*15:01 specifically presenting SARS-CoV-2 peptides could form a neo-ligand interacting with KIR3DS1. Similarly, a putative neo-ligand for KIR2DS4 could arise from other HLA-I molecules presenting SARS-CoV-2 peptides expressed on infected/activated lung antigen presenting cells. Conclusions Our results support a crucial role of NKcs in the clinical variability of COVID-19 with specific KIR/Ligand interactions associated to disease severity.

Transarterial radioembolization (TARE), also called radioembolization or selective internal radiation therapy, is an interventional radiology technique used to treat primary liver tumors and liver metastases. The aim of this therapy is to deliver tumoricidal doses of radiation to liver tumors while selecting a safe radiation dose limit for nontumoral liver and lung tissue. Hence, correct treatment planning is essential to obtaining good results. However, this treatment invariably results in some degree of irradiation of normal liver parenchyma, inducing different radiologic findings that may affect follow-up image interpretation. When evaluating treatment response, the treated area size, tumor necrosis, devascularization, and changes seen at functional MRI must be taken into account. Unlike with other interventional procedures, with TARE, it can take several months for the tumor response to become evident. Ideally, responding lesions will show reduced size and decreased enhancement 3-6 months after treatment. In addition, during follow-up, there are many imaging findings related to the procedure itself (eg, peritumoral edema, inflammation, ring enhancement, hepatic fibrosis, and capsular retraction) that can make image interpretation and response evaluation difficult. Possible complications, either hepatic or extrahepatic, also can occur and include biliary injuries, hepatic abscess, radioembolization-induced liver disease, and radiation pneumonitis or dermatitis. A complete understanding of these possible posttreatment changes is essential for correct radiologic interpretations during the follow-up of patients who have undergone TARE.

Switching dual therapy with dolutegravir (DTG) plus rilpivirine (RPV) was assessed in the SWORD-1 and SWORD-2 studies. Real-life data regarding the immunological impact of this approach on CD4+ and CD8+ T lymphocyte counts and the CD4/CD8 ratio are scarce. We evaluated this strategy on the basis of clinical practice data.A multicentric retrospective cohort study.Treatment-experienced virologically suppressed HIV-1-infected patients who were switched to DTG plus RPV were included. Using different models for paired data, we evaluated the efficacy and immune status in terms of CD4+ and CD8+ T-cell counts and CD4/CD8 ratio at 24 and 48 weeks of treatment.The study population comprised of 524 patients from 34 centers in Spain. Men accounted for 76.9% of patients, with a median age of 53 years. Patients receiving DTG plus RPV reached weeks 24 and 48 in 99.4% and 83.8% of cases, respectively, with only three (0.57%) virological failures. We found a significant decrease in CD8+ T-cell count (log OR –40) at week 24 and an increase in CD4+ T-cell count at week 48 (log OR +22.8). In acquired immunodeficiency syndrome-diagnosed patients, we found a significant increase in the CD4+ T-cell count at week 48 (log OR = 41.7, P = .0038), but no significant changes in the CD8+ T-cell count (log OR = –23.4, P = .54). No differences were found in the CD4/CD8 ratio between the acquired immunodeficiency syndrome subgroup and sex or age.In patients with controlled treatment, dual therapy with DTG plus RPV slightly improved the immune status during the first 48 weeks after switching, not only in terms of CD4+ T-cell count but also in terms of CD8+ T-cell count, with persistently high rates of viral control.

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Pandemic influenza A(H1N1)pdm09 virus has retained its ability to infect swine whilst developing the ability to transmit effectively between humans, thus making the pig a valuable model for studying disease pathogenesis in both species. Lung lesions in pigs caused by infection with influenza A viruses vary in both their severity and distribution with individual lung lobes exhibiting lesions at different stages of infection pathogenic development and disease resolution. Consequently, investigating interactions between the virus and host and their implications for disease pathogenesis can be complicated. Studies were undertaken to investigate the discrete expression of pro- and anti-inflammatory mediators during lung lesion formation in pigs during infection with influenza A(H1N1)pdm09 (A/Hamburg/05/09) virus. Laser capture microdissection was used to identify and select lung lobules containing lesions at different stages of development. Dissected samples were analysed using quantitative RT-PCR to assess pro- and anti-inflammatory cytokine mRNA transcripts. Differential expression of the immune mediators IL-8, IL-10 and IFN-γ was observed depending upon the lesion stage assessed. Upregulation of IFN-γ, IL-8 and IL-10 mRNA was observed in stage 2 lesions, whereas decreased mRNA expression was observed in stage 3 lesions, with IL-8 actively downregulated when compared with controls in both stage 3 and stage 4 lesions. This study highlighted the value of using laser capture microdissection to isolate specific tissue regions and investigate subtle differences in cytokine mRNA expression during lesion development in pigs infected with influenza A(H1N1)pdm09.