HLA Allele Frequencies and Association with Severity of COVID-19 Infection in Northern Italian Patients.

HLA allelic distribution was analysed in a cohort of 96 Northern Italian subjects (53M/43F) (mean age 59.9 ± 13.3 years) from Lombardy who developed COVID-19 during the first two pandemic waves to investigate possible correlations between HLA molecules and disease severity. An important role of HLA- B and HLA-C loci in modulating the clinical severity of COVID-19 disease was identified. In particular, the HLA-B07 supertype was observed to be associated with a significant risk for severe disease; conversely, the HLA-B27 supertype and C*12:02 allele played a protective role as they were associated with milder disease. These associations were confirmed after applying a multinomial regression analysis to adjust the correlation for age, gender and comorbidities with COVID-19 severity. Though the power of results is limited by the small sample size, data herein contribute to shedding light on the role played by genetic background in COVID-19 infection.

Letter to the editor: COVID in patients with brain injury with a disorder of consciousness: a pathogenetic theory.

We recently published in this journal (Caronni and colleagues, Brain Injury, 2021-04-16) the first description of the spread of the SARS-CoV-2 infection in a cohort of brain injured patients with a disorder of consciousness (DOC). Surprisingly enough we showed that, in these patients, the COVID was moderate and did not result in fatalities. The pathogenesis of the COVID is characterized by the profound dysregulation of the immune system. To explain our findings, we speculated that the immunosuppression due to the brain injury could be protective against the development of the COVID in patients with DOC. More recently, a second group of authors (Marino and colleagues, PLoSOne, 2021-06-30) described the course of the COVID in an independent cohort of patients with DOC. Since our results were quite unexpected, we have been very comforted by the data reported by Marino and colleagues. Moreover, these data also offer a unique opportunity to further evaluate our theory regarding the COVID pathogenesis in patients with DOC. In the current Letter to the Editor it is shown that the independent data presented by Marino and colleagues do support our theory. Waiting for larger cohorts to further test it (and in case falsify it), our interpretation seems to remain valid.

NK Cell Subpopulations and Receptor Expression in Recovering SARS-CoV-2 Infection.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the pandemic of coronavirus disease (COVID-19). Whereas in most cases COVID-19 is asymptomatic or pauci-symptomatic, extremely severe clinical forms are observed. In this case, complex immune dysregulations and an excessive inflammatory response are reported and are the main cause of morbidity and mortality. Natural killer cells are key players in the control of viral infection, and their activity is regulated by a tight balance between activating and inhibitory receptors; an alteration of NK activity was suggested to be associated with the development of severe forms of COVID-19. In this study, we analyzed peripheral NK cell subpopulations and the expression of activating and inhibitory receptors in 30 patients suffering from neurological conditions who recovered from mild, moderate, or severe SARS-CoV-2 infection, comparing the results to those of 10 SARS-CoV-2-uninfected patients. Results showed that an expansion of NK subset with lower cytolytic activity and an augmented expression of the 2DL1 inhibitory receptor, particularly when in association with the C2 ligand (KIR2DL1-C2), characterized the immunological scenario of severe COVID-19 infection. An increase of NK expressing the ILT2 inhibitory receptor was instead seen in patients recovering from mild or moderate infection compared to controls. Results herein suggest that the KIR2DL1-C2 NK inhibitory complex is a risk factor toward the development of severe form of COVID-19. Our results confirm that a complex alteration of NK activity is present in COVID-19 infection and offer a molecular explanation for this observation.

Clinical course of SARS-CoV-2 infection in patients with severe acquired brain injury and a disorder of consciousness: an observational study.

Purpose: SARS-CoV-2 infection can cause the coronavirus disease (COVID), ranging from flu-like symptoms to interstitial pneumonia. Mortality is high in COVID pneumonia and it is the highest among the frailest. COVID could be particularly serious in patients with severe acquired brain injury (SABI), such as those with a disorder of consciousness. We here describe a cohort of patients with a disorder of consciousness exposed to SARS-CoV-2 early after their SABI.Materials and methods: The full cohort of 11 patients with SABI hospitalized in March 2020 in the IRCCS Fondazione Don Gnocchi rehabilitation (Milan, Italy) was recruited. Participants received SARS-CoV-2 testing and different clinical and laboratory data were collected.Results: Six patients contracted SARS-CoV-2 and four of them developed the COVID. Of these, one patient had ground-glass opacities on the chest CT scan, while the remaining three developed consolidations. No patient died and the overall respiratory involvement was mild, requiring in the worst cases low-flow oxygen.Conclusions: Here we report the clinical course of a cohort of patients with SABI exposed to SARS-CoV-2. The infection spread among patients and caused COVID in some of them. Unexpectedly, COVID was moderate, caused at most mild respiratory distress and did not result in fatalities.

Inpatient Care during the COVID-19 Pandemic: A Survey of Italian Physicians.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a potentially fatal disease that is of great global public health concern. OBJECTIVE: We explored the clinical management of inpatients with COVID-19 in Italy. METHODS: A self-administered survey was sent by email to Italian physicians caring for adult patients with COVID-19. A panel of experts was selected according to their clinical curricula and their responses were analyzed. RESULTS: A total of 1,215 physicians completed the survey questionnaire (17.4% response rate). Of these, 188 (15.5%) were COVID-19 experts. Chest computed tomography was the most used method to detect and monitor COVID-19 pneumonia. Most of the experts managed acute respiratory failure with CPAP (56.4%), high flow nasal cannula (18.6%), and non-invasive mechanical ventilation (8%), while an intensivist referral for early intubation was requested in 17% of the cases. Hydroxychloroquine was prescribed as an antiviral in 90% of cases, both as monotherapy (11.7%), and combined with protease inhibitors (43.6%) or azithromycin (36.2%). The experts unanimously prescribed low-molecular-weight heparin to patients with severe COVID-19 pneumonia, and half of them (51.6%) used a dose higher than standard. The respiratory burden in patients who survived the acute phase was estimated as relevant in 28.2% of the cases, modest in 39.4%, and negligible in 9%. CONCLUSIONS: In our survey some major topics, such as the role of non-invasive respiratory support and drug treatments, show disagreement between experts, likely reflecting the absence of high-quality evidence studies. Considering the significant respiratory sequelae reported following COVID-19, proper respiratory and physical therapy programs should be promptly made available.