CO0002 LOSS OF SELF-TOLERANCE IN SARS-COV-2 INFECTION: IMMUNOLOGICAL ASSESSMENT OF A CONVALESCENT COHORT

Background:

Some infectious agents may act as inducers of autoimmune conditions1. Despite SARS-CoV-2 infection can induce autoimmune phenomena in infected people2, individual risk factors or underlining mechanisms leading to loss of immunological tolerance are still unknown.

Objectives:

To assess the rate of development of autoantibodies in convalescent SARS-CoV-2 patients and their relation on infection clinical course and disease parameters.

Methods:

One-hundred and nine convalescent SARS-CoV-2 patients were studied and underwent multidisciplinary assessment in a Day Hospital clinical setting. For each patient, demographic, clinical and immunological data were collected and, at study entry, autoimmune profile [antinuclear antibodies (ANAs), antibodies reacting with extractable nuclear antigens (anti-ENA), antineutrophil cytoplasmic antibodies (ANCAs), Lupus anticoagulant (LA), anticardiolipin antibodies (aCL) IgM and IgG, anti-β2 glycoprotein I (anti-β2GPI) IgM and IgG] was assessed by Fluorescent immunoassay. Moreover, IL-6 plasma levels were assessed by ELISA (ELLA).

Results:

After a median time from hospitalization for SARS-CoV-2 infection of 53.3 ± 0.9 days, 55(50.5%) SARS-CoV-2 convalescent patients showed the positivity (ABpos) of at least one autoantibody. In particular, 31(28.4%) were positive for LA, 11(10.1%) for IgM-RF, 8(7.3%) for ANA and 6(5.5.%) for IgG-aCL whilst less than 2% showed other autoantibody positivities (IgM-aCL, IgG-anti-β2GPI, ENA, ACPA, c-ANCA, Scl70 and RNP). Analyzing the patient-related characteristics associated with the development of autoimmunity, convalescent male patients were more likely characterized by the development of antiphospholipid antibodies (aPL) (37.3%) than female (16.7%; p=0.02). Considering the disease-related characteristics, convalescent SARS-CoV-2 patients who experienced severe pneumonia (i.e., oxygen support need) during hospitalization, more likely received IL-6R-inhibitor administration (47.3%) and developed more than one autoantibody (87.5%) (aPL + another AB) than convalescent SARS-CoV-2 patients who did not need oxygen support [(12.5%; p=0.02) (OR95%IC: 9.5(1.4-109.1)] or IL-6R-inihibitor (1.9%; p<0.001). Finally, assessing cytokines plasma levels in convalescent SARS-CoV-2 patients stratified based on the development of autoantibodies we found that, despite a significant reduction of IL-6 plasma levels from hospitalization, convalescent SARS-CoV-2 patients who developed autoantibody positivity had higher IL-6 plasma levels (8.5 ± 2.5 pg/ml) than convalescent SARS-CoV-2 ABnegpatients (5.6 ± 1.5 pg/ml; p=0.07), mostly if considered autoantibodies other than aPL (15.4 ± 7.7 pg/ml)(p=0.01).

Conclusion:

Loss of self-tolerance is a common phenomenon in the medium-term follow-up of SARS-CoV-2 convalescent patients whose occurrence is dependent by a severe disease course and by an aberrant host inflammatory response. Long-term follow-up will reveal AB persistency and their clinical impact.

References:

[1]Barzilai O, et al. Current Opinion in Rheumatology 2007.

[2]Zhou Y, et al. Clin Transl Sci. 2020.

Disclosure of Interests:

None declared

Atherosclerosis and cardiovascular involvement in celiac disease: the role of autoimmunity and inflammation

OBJECTIVE

The aim of this review is to explore the evidence about the association among celiac disease (CD), atherosclerosis (AS) and cardiovascular (CV) diseases, and the role of inflammation in this connection.

MATERIALS AND METHODS

A systematic literature search was conducted using PubMed, EMBASE, and Cochrane Library for the association among CD, AS and CV diseases.

RESULTS

Several studies reported the association of CD with accelerated AS, as evidenced by the alterations of a number of parameters indicative of subclinical AS, as increased carotid artery intima-media thickness, endothelial dysfunction and increased arterial stiffness. In addition, recent evidence reported an increase of CV diseases prevalence in CD patients respect to controls, many of which including ischemic diseases as acute myocardial infarction and angina pectoris, as well as death from ischemic heart disease, and, more rarely, stroke for cerebrovascular involvement. Other not-ischemic CV diseases associated with CD are represented by dilated cardiomyopathy, atrial fibrillation, and myocarditis.

CONCLUSIONS

On the basis of the reported association among CD, AS and CV diseases, we suggest to perform a more detailed CV risk assessment in all CD patients than what is currently being achieved in clinical practice, in order to scan and treat modifiable CV risk factors in these patients. In particular, we suggest to resort to instrumental techniques to detect AS in the subclinical stage, in order to prevent AS development and CV diseases in CD patients.

The association between sarcopenia and functional outcomes among older patients with hip fracture undergoing in-hospital rehabilitation

This study evaluates the prevalence of sarcopenia among older people admitted to a rehabilitation unit after hip fracture and the association between sarcopenia and functional outcomes. The results show that sarcopenia had a negative impact on functional recovery. The assessment of sarcopenia among older adults receiving rehabilitation programs is crucial.

INTRODUCTION

Sarcopenia is a highly prevalent geriatric syndrome associated with adverse outcomes, including falls, disability, institutionalization, and mortality. Few studies assessed sarcopenia among older adults receiving rehabilitation programs.

METHODS

Patients aged 70 years or more consecutively admitted to in-hospital rehabilitation programs that had suffered from hip fracture entered the study. Sarcopenia was defined according to the Foundation for National Institutes of Health (FNIH) criteria. Multivariable linear regression models were used to analyze the association between the sarcopenia and functional recovery.

RESULTS

The recruited population was composed of 127 patients, with a mean age of 81.3 ± 4.8 years, predominantly females (64.6%). Using the criteria proposed by the FNIH, patients with a diagnosis of sarcopenia were 43 (33.9%). After adjustment for potential confounders, participants with sarcopenia had a significant increased risk of incomplete functional recovery compared with non-sarcopenic patients (OR 3.07, 95% CI 1.07-8.75). Compared with participants without sarcopenia, those with sarcopenia showed lower Barthel index scores at the time of discharge from the rehabilitation unit (69.2 versus 58.9, respectively; p < 0.001) and after 3 months of follow-up (90.9 versus 80.5, respectively; p = 0.02).

CONCLUSIONS

These findings support the systematic assessment of sarcopenia among older adults receiving rehabilitation programs to assist in the development of personalized treatment plans aimed at improving functional outcomes.

Animal-Derived Protein Consumption Is Associated with Muscle Mass and Strength in Community-Dwellers: Results from the Milan EXPO Survey

OBJECTIVES

Behavioral factors, including protein intake, influence the quantity and quality of skeletal muscle. The aim of this study was to explore the relationship between animal-derived protein intake and muscle mass and function in a large sample of unselected community-dwellers.

MATERIAL AND METHODS

The VIP (Very Important Protein) study, conducted during Expo 2015 in Milan, was a population survey aimed at assessing major health metrics in a population outside of the research setting, with a special focus on the relation between animal-derived protein intake and muscle mass and function. A brief questionnaire exploring lifestyle habits, dietary preferences and the consumption of selected foods was administered. Muscle mass was estimated by calf circumference (CC) and mid-arm muscle circumference (MAMC) of the dominant side. Muscle strength of upper and lower extremities was assessed through handgrip strength testing and repeated chair stand test, respectively.

RESULTS

The mean age of the 1,853 participants was 50.3 years (standard deviation: 15.7; range: 18-98 years), of whom 959 (51.7%) were women. Participants in the highest tertile of protein consumption showed better performance at both the handgrip strength (p <0.001) and chair stand tests than those in the lowest tertile (p <0.01). The same results were found for CC (p <0.001) and MAMC (p <0.001). Participants with high protein intake and engaged in regular physical activity showed the higher scores in all the assessed domains.

CONCLUSIONS

The results of the VIP survey suggest an association between animal-derived protein intake and muscle mass and strength across ages. Our findings also indicate a synergistic effect of animal-derived protein intake and physical activity on muscle-related parameters.