The significant comparisons are shown. AC antibodies are expressed as medians and interquartile ranges and were compared with the Wilcoxon test. DataSheet_1.docx (1.6M) GUID:?2184E4FB-5C05-4D9C-98B3-86A1AC7E003D Supplementary Table?3: Comparison of the serum levels of cytokines, chemokines and AC antibodies in patients with COVID-19, 6 months after recruitment according to the diagnosis of a sustained humoral immune response. The serum levels of the cytokines and chemokines are expressed as medians and interquartile ranges and were compared with the Wilcoxon test. DataSheet_1.docx (1.6M) GUID:?2184E4FB-5C05-4D9C-98B3-86A1AC7E003D Supplementary Table?4: Univariate logistic regression analysis of the statistically significant features associated to the development of a sustained humoral immune response in patients with COVID-19. DataSheet_1.docx (1.6M) GUID:?2184E4FB-5C05-4D9C-98B3-86A1AC7E003D Supplementary Table?5: Repeated-measures analysis of the differential serum levels of cytokines 6 months after recruitment considering Sotrastaurin (AEB071) Sotrastaurin (AEB071) the disease severity and the development of a sustained humoral immune response. DataSheet_1.docx (1.6M) GUID:?2184E4FB-5C05-4D9C-98B3-86A1AC7E003D Data Availability StatementThe original contributions presented in the study are included in the article/ Supplementary Material . Further inquiries can be directed to the corresponding authors. Abstract Background Until now, most of the research addressing long-term humoral responses in coronavirus disease 2019 (COVID-19) had only evaluated the serum titers Sotrastaurin (AEB071) of anti-severe acute Rabbit polyclonal to ANG4 respiratory syndrome coronavirus 2 (SARS-CoV-2) IgGs, without the assessment of the baseline antiviral clinical and immune profile, which is the aim of this study and may be the key factor leading to a broad and sustained antibody response. Methods We included 103 patients with COVID-19. When the patients sought medical attention (baseline), a blood sample was drawn to perform immunophenotype of lymphocytes by flow cytometry. The patients were assessed 15 days after baseline and then every month until the third month, followed by a last visit 6 months after recruitment. We evaluated the anti-SARS-COV-2 IgG at all time points, and the serum levels of cytokines, chemokines, anti-cellular (AC) antibodies and neutrophil extracellular traps were also assessed during the follow-up. The primary outcome of the study was the presence of a sustained immune humoral response, defined as an anti-SARS-CoV-2 IgG titer >4.99 arbitrary units/mL in at least two consecutive measures. We used generalized lineal models to assess the features associated with this outcome and to assess the effect of the changes in the cytokines and chemokines throughout time on the development of a sustained humoral immune response. Results At baseline the features associated to a sustained immune humoral response were the diagnosis of critical disease, absolute number of lymphocytes, serum IP-10, IL-4, IL-2, regulatory T cells, CD8+ T cells, and positive AC antibodies. Critical illness and the positivity of AC antibodies were associated with a sustained humoral immune response after 3 months, whilst critical illness and serum IL-13 were the explanatory variables after 6 months. Conclusion A sustained immune humoral response is strongly related to critical COVID-19, which is characterized by the presence of AC antibodies, quantitative abnormalities in the T cell compartment, and the serum cytokines and chemokines during acute infection and throughout time. Keywords: SARS-CoV-2, humoral response, COVID-19, lymphopenia, anti-cellular antibodies Introduction Severe acute respiratory syndrome (SARS-CoV-2) has affected 78 million individuals and is responsible for over 1.7 million deaths to date.