Patients with coronavirus disease 2019 characterized by dysregulated levels of membrane and soluble cluster of differentiation 48.

BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), can progress into a severe form of acute lung injury. The cosignaling receptor cluster of differentiation 48 (CD48) exists in membrane-bound (mCD48) and soluble (sCD48) forms and has been reported to be implicated in antiviral immunity and dysregulated in several inflammatory conditions. Therefore, CD48 dysregulation may be a putative feature in COVID-19-associated inflammation that deserves consideration. OBJECTIVE: To analyze CD48 expression in lung autopsies and peripheral blood leukocytes and sera of patients with COVID-19. The expression of the CD48 ligand 2B4 on the membrane of peripheral blood leukocytes was also assessed. METHODS: Twenty-eight lung tissue samples obtained from COVID-19 autopsies were assessed for CD48 expression using gene expression profiling immunohistochemistry (HTG autoimmune panel). Peripheral whole blood was collected from 111 patients with COVID-19, and the expression of mCD48 and of membrane-bound 2B4 was analyzed by flow cytometry. Serum levels of sCD48 were assessed by enzyme-linked immunosorbent assay. RESULTS: Lung tissue of patients with COVID-19 showed increased CD48 messenger RNA expression and infiltration of CD48+ lymphocytes. In the peripheral blood, mCD48 was considerably increased on all evaluated cell types. In addition, sCD48 levels were significantly higher in patients with COVID-19, independently of disease severity. CONCLUSION: Considering the changes of mCD48 and sCD48, a role for CD48 in COVID-19 can be assumed and needs to be further investigated.

Efficacy of anti-SARS-CoV-2 mRNA vaccine in systemic autoimmune disorders: induction of high avidity and neutralising anti-RBD antibodies.

OBJECTIVES: In patients with systemic autoimmune rheumatic disorders (SARDs), vaccination with SARS-CoV-2 mRNA vaccines has been proposed. The aim of this study is to evaluate the immune response elicited by vaccination with mRNA vaccine, testing IgM, IgA and IgG antibodies to SARS-CoV-2 receptor-binding domain (RBD) and measuring neutralising antibodies. METHODS: IgG, IgM and IgA anti-RBD antibodies were measured in 101 patients with SARDs. Antibodies inhibiting the interaction between RBD and ACE2 were evaluated. Antibody avidity was tested in a chaotropic ELISA using urea. Twenty-one healthcare workers vaccinated with mRNA vaccine served as control group. RESULTS: Anti-RBD IgG and IgA were produced after the first dose (69% and 64% of the patients) and after the boost (93% and 83%). Antibodies inhibiting the interaction of RBD with ACE2 were detectable in 40% of the patients after the first dose and 87% after boost, compared with 100% in healthy controls (p<0.01). Abatacept and mycophenolate had an impact on the titre of IgG anti-RBD antibodies (p<0.05 and p<0.005, respectively) and on the amount of neutralising antibodies. No effect of other therapies was observed. Vaccinated patients produce high avidity antibodies, as healthy controls. CONCLUSIONS: These data show that double-dose vaccination induced in patients with SARDs anti-RBD IgG and IgA antibodies in amounts not significantly different from controls, and, most interestingly, characterised by high avidity and endowed with neutralising activity.

Obesity prolongs the hospital stay in patients affected by COVID-19, and may impact on SARS-COV-2 shedding.

INTRODUCTION: On the last three months the new SARS-COV-2 coronavirus has created a pandemic, rapidly spreading all around the world. The aim of the study is to investigate whether obesity impacts on COVID-19 morbidity. METHODS: One hundred consecutive patients with COVID-19 pneumonia admitted in our Medical Unit were evaluated. Anthropometric parameters and past medical history were registered. Nasopharyngeal swab samples and biochemical analysis were obtained at admission and during hospital stay. RESULTS: Patients with (OB, 29) and without obesity (N-OB, 71) were similar in age, gender and comorbidities, with the exception of hypertension that was more frequent in OB group. At admission, inflammatory markers were higher in OB than N-OB group. OB group showed a worse pulmonary clinical picture, with lower PaO2 (57 ± 15 vs. 68 ± 14 mmHg, p = 0.042), and SaO2 (88 ± 6 vs. 92 ± 5%, p = 0.049) at admission consequently requiring higher volumes of oxygen (Fi02: 38 ± 15 vs. 29 ± 19%, p = 0.047) and a longer period to achieve oxygen weaning (10 ± 6 vs. 15 ± 7 days, p = 0.03). OB group also had positive swabs for longer time (19 ± 8 vs. 13 ± 7, days, p = 0.002), and required longer hospital stay (21 ± 8 vs. 13 ± 8, days, p = 0.0008). Partial least square regression analysis showed that BMI, age and CRP at admission were related to longer length of hospital stay, and time for negative swab. On the contrary, in this cohort, obesity did not predict higher mortality. CONCLUSIONS: Subjects with obesity affected by COVID-19 require longer hospitalization, more intensive and longer oxygen treatment, and they may have longer SARS-COV-2 shedding.