COVID-19 and Autoimmunity: A Single Center Prospective Follow-up Study

Background Various factors, such as viral infections, can act as triggers for the development of autoimmune diseases. In our recent study we reported the presence of autoantibodies in patients diagnosed with COVID-19. To verify whether these autoantibodies persisted over time and led to the development of chronic autoimmune diseases, we conducted a follow-up study at 3 and 6 months after admission. Methods Thirteen of 40 patients enrolled in the previous study gave their consent to the analysis. The same autoimmunity tests performed at the time of diagnosis were carried out in these patients during follow up. Results We showed, compatibly with an acute inflammatory response, that two patients were negative 6 months after diagnosis. In nine patients, autoantibodies were still present at follow-up. Among them, one patient had only ENA positivity. Another patient developed strong positivity for ANA and M2-β and Ku antigens. Currently, the symptoms do not meet full diagnostic criteria for diagnosis of polymyositis, but the patient is closely monitored to check its possible onset. Three patients developed: transient alopecia, autoimmune thrombocytopenia and hearing loss. Other four patients did not show any clinical symptoms. Conclusions In conclusion, our data show that after 6 months, the autoantibodies are still present in the majority of patients. Arch Clin Biomed Res 2021; 5 (6): 1018-1026 DOI: 10.26502/acbr.50170220 Archives of Clinical and Biomedical Research Vol. 5 No. 6 – December 2021. [ISSN 2572-9292]. 1019 Further investigations will be necessary to check whether these patients will become negative over time or may develop clinical symptoms compatible with the onset of longer-term chronic autoimmune diseases.


SARS-CoV-2 (Severe Acute Respiratory Syndrome Corona
Virus 2) is the agent responsible for the acute respiratory disease named COVID-19 (Corona Virus Disease 2019). The severity of the pathologies deriving from coronavirus infections is very variable, since these viruses are responsible for both some common cold syndromes and severe respiratory syndromes such as SARS (Severe Acute Respiratory Syndrome) and MERS (Middle East Respiratory Syndrome) [1][2][3]. In the case of COVID-19 patients, the main symptomatology is similar to a flu-like illness (e.g. fever, cough, fatigue), but in some cases it can evolve into severe clinical pictures, leading to multiorgan dysfunction syndrome and even leading to death [4][5][6]. It has been observed that the evolution of SARS-CoV-2 infection seems to have similar characteristics to the cytokine release syndrome [7,8]. These data were confirmed also in a study that we recently published, where we showed how increased inflammatory markers values (i.e. IL6) are related to a worst clinical outcome and could be considered a reliable diagnostic criterion to identify subjects with a worst prognosis [9]. In addition to the inflammatory response, it has been shown that in COVID-19 patients the presence of the virus could affect the autoimmunity too. Although the etiopathogenesis of autoimmune diseases is very complex and the underlying mechanisms have not been fully described yet, it is known how different infectious, bacterial, viral, or fungal agents can represent a trigger for the development of autoimmune diseases [10].
Furthermore, different studies have been reported suggesting a possible association between SARS-CoV-2 infection and the development of some autoimmune diseases such as systemic lupus erythematosus [15], Guillain-Barré syndrome, Miller Fisher syndrome, immune thrombocytopenia purpura and Kawasaki disease [16]. However, up to now, the data reported are still controversial. Thus, it is essential to carry out follow-up studies to understand whether the autoantibody presence can be explained as an epiphenomenon, a crossreaction, a pre-existing undiagnosed pathology, or a new autoimmune disease triggered by COVID-19. During the first wave of the SARS-CoV-2 pandemic, we investigated the autoimmune pattern of hospitalized patients with a severe clinical picture; to check a possible correlation between autoantibody presence and clinical phenotype. We thus enrolled 40 patients between 20 and 97 years (70% male and 30% female) who had been admitted to the sub-intensive medicine ward. None of these patients had a history of autoimmune disease or related symptoms prior to admission.
The most common autoantibodies were studied in these patients and a correlation between SARS-CoV-2 infection and the development of some of them was highlighted. In particular, the statistically significant ones were anti-nucleus antibodies (ANA), atypical anti-neutrophil cytoplasmatic antibodies (X-ANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA IgA). Therefore, in our study, we highlighted that there is a correlation between the response to SARS-CoV-2, the presence of autoantibodies and the clinical outcome [9]. To find out whether the autoantibody presence was transient, persisted over time and possibly correlated with the development of autoimmune diseases, we performed a follow-up study on 13 of the 40 patients initially enrolled.
Patients were tested at 3 (t3) and 6 (t6) months from hospitalization for the same autoantibodies considered at admission (t0). This work allowed us to observe that most patients maintained an altered autoantibody profile after 6 months.

Study design
Thirteen convalescent COVID-19 patients already analysed in a previous study [9] were enrolled for a follow-up analysis.
The considered time points were 3 (t3) e 6 (t6) months. The patients were aged between 19 and 77 years and were 6 men and 7 women. All patients who participated to the study signed informed consent.

Blood autoimmunity tests
The autoantibodies considered were analysed as described in the previous study [9]. Briefly, antiphospholipid antibodies were detected using chemiluminescent assay (ACL AcuStar, Anti-neutrophil Cytoplasmic (ANCA) and Anti-nuclear Antibody (ANA) were detected by indirect Immunofluorescence (IIF) using EUROIMMUN test kits.

Confirmatory tests were performed by line-blot technology
following the manufacturer's instructions (EUROIMMUN).

Statistical Analyses
Excel software was used to evaluate the presence of autoantibodies during the follow up.

3.Results
The inflammatory and autoimmune spheres can be influenced by various factors (i.e. virus) and they can change over time [17]. In our recent work, we observed how SARS-CoV-2 infection is also linked to these status [9]. In the study we

Conclusion
In conclusion, our study is the first to investigate the persistence of autoantibodies in COVID-19 patients over time and highlights how most of the enrolled population maintains an alteration of the autoantibody structure even after 6 months from acute infectious event. Although the number of analysed cases is small, our results suggest the importance of monitoring the presence of autoantibodies over a longer period to evaluate the possible development of autoimmune diseases.