Anticardiolipin and anti-beta-2 glycoprotein I antibodies in patients with moderate or severe COVID-19

Prevalence of antiphospholipid antibodies in COVID-19 patients: A meta-analysis

OBJECTIVE

In some reports, antiphospholipid antibodies (aPL) prevalence is higher in COVID-19 patients. This study intended to compare aPL prevalence between COVID-19 patients and healthy controls, and differences in aPL types using meta-analysis.

METHODS

This work retrieved published literature about association between COVID-19 and aPL from Embase, Web of Science, PubMed, and The Cochrane Library databases. The observation group was COVID-19 patients, and the control group was healthy individuals. Outcome measures contained any of following aPLs: classic aPL: anti-cardiolipin antibodies (aCL) and anti-β2-glycoprotein-1 antibodies (Anti-β2GP1); other non-criteria aPL: anti-phosphatidylserine/prothrombin antibodies (aPS/PT) and anti-annexin-V antibodies (AnV). Meta-analysis was done on Review Manager 5.4.

RESULTS

10 studies involving 2288 patients were deemed eligible for inclusion. The results of the meta-analysis showed that the prevalence of Classic aPL and Any aPL in the COVID-19 group was significantly higher than in the healthy group (Classic aPL, RR = 2.55, 95 % CI = 1.83-3.55, P < 0.00001; Any aPL, RR = 2.34, 95 % CI = 1.46-3.77, P = 0.0005). Anti-β2GP1 IgA antibodies were the most common aPL in COVID-19 patients, with a significantly higher prevalence than in the healthy group (RR = 4.26, 95 % CI = 2.84-6.40, P < 0.00001). The prevalence of the four types of IgM aPL was significantly higher in the COVID-19 group compared to the healthy group, while there was no significant difference in aPL IgG between the two groups.

CONCLUSION

The prevalence of aPL in COVID-19 patients was significantly higher than in the healthy control group. IgM aPL was more easily detectable in the early stages of COVID-19 infection, while IgG aPL may be of more concern in the later time points of the immune epidemiology following SARS-CoV-2 infection.

High prevalence of long COVID in anti-TPO positive euthyroid individuals with strongly elevated SARS-CoV-2-specific T cell responses and moderately raised anti-spike IgG levels 23 months post-infection

Introduction

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection, the causative agent of coronavirus disease 2019 (COVID-19), causes post-acute infection syndrome in a surprisingly large number of cases worldwide. This condition, also known as long COVID or post-acute sequelae of COVID-19, is characterized by extremely complex symptoms and pathology. There is a growing consensus that this condition is a consequence of virus-induced immune activation and the inflammatory cascade, with its prolonged duration caused by a persistent virus reservoir.

Methods

In this cross-sectional study, we analyzed the SARS-CoV-2-specific T cell response against the spike, nucleocapsid, and membrane proteins, as well as the levels of spike-specific IgG antibodies in 51 healthcare workers, categorized into long COVID or convalescent control groups based on the presence or absence of post-acute symptoms. Additionally, we compared the levels of autoantibodies previously identified during acute or critical COVID-19, including anti-dsDNA, anti-cardiolipin, anti-β2-glycoprotein I, anti-neutrophil cytoplasmic antibodies, and anti-thyroid peroxidase (anti-TPO). Furthermore, we analyzed the antibody levels targeting six nuclear antigens within the ENA-6 S panel, as positivity for certain anti-nuclear antibodies has recently been shown to associate not only with acute COVID-19 but also with long COVID. Finally, we examined the frequency of diabetes in both groups. Our investigations were conducted at an average of 18.2 months (convalescent control group) and 23.1 months (long COVID group) after confirmed acute COVID-19 infection, and an average of 21 months after booster vaccination.

Results

Our results showed significant differences between the two groups regarding the occurrence of acute infection relative to administering the individual vaccine doses, the frequency of acute symptoms, and the T cell response against all structural SARS-CoV-2 proteins. A statistical association was observed between the incidence of long COVID symptoms and highly elevated anti-TPO antibodies based on Pearson's chi-squared test. Although patients with long COVID showed moderately elevated anti-SARS-CoV-2 spike IgG serum antibody levels compared to control participants, and further differences were found regarding the positivity for anti-nuclear antibodies, anti-dsDNA, and HbA1c levels between the two groups, these differences were not statistically significant.

Disscussion

This study highlights the need for close monitoring of long COVID development in patients with elevated anti-TPO titers, which can be indicated by strongly elevated SARS-CoV-2-specific T cell response and moderately raised anti-spike IgG levels even long after the acute infection. However, our results do not exclude the possibility of new-onset thyroid autoimmunity after COVID-19, and further investigations are required to clarify the etiological link between highly elevated anti-TPO titers and long COVID.

IgA Anti-β2-Glycoprotein I Antibodies as Markers of Thrombosis and Severity in COVID-19 Patients

Patients with COVID-19 may develop a hypercoagulable state due to tissue and endothelial injury, produced by an unbalanced immune response. Therefore, an increased number of thromboembolic events has been reported in these patients. The aim of this study is to investigate the presence of antiphospholipid antibodies (aPL) in COVID-19 patients, their role in the development of thrombosis and their relationship with the severity of the disease. In this retrospective study, serum samples from 159 COVID-19 patients and 80 healthy donors were analysed for the presence of aPL. A total of 29 patients (18.2%) and 14 healthy donors (17.5%) were positive for aPL. Nineteen COVID-19 patients (12%) but no healthy donor presented a positive percentage of the IgA isotype aPL. IgA anti-β2-glycoprotein I antibodies (anti-β2GPI) were the most frequent type (6.3%) in patients but was not detected in any healthy donor. The positivity of this antibody was found to be significantly elevated in patients with thromboembolic events (25% vs. 5%, p = 0.029); in fact, patients with positive IgA anti-β2GPI had an incidence of thrombosis over six times higher than those who had normal antibody concentrations [OR (CI 95%) of 6.67 (1.5-30.2), p = 0.014]. Additionally, patients with moderate-severe disease presented a higher aPL positivity than patients with mild disease according to the Brescia (p = 0.029) and CURB-65 (p = 0.011) severity scales. A multivariate analysis showed that positivity for IgA anti-β2GPI is significantly associated with disease severity measured by CURB-65 [OR (CI 95%) 17.8 (1.7-187), p = 0.0016]. In conclusion, COVID-19 patients have a significantly higher positive percentage of the IgA isotype aPL than healthy donors. IgA anti-β2GPI antibodies were the most frequently detected aPL in COVID-19 patients and were associated with thrombosis and severe COVID-19 and are thus proposed as a possible marker to identify high-risk patients.

Anticardiolipin and anti-beta 2-glycoprotein I antibodies in patients with unexplained articular manifestations

OBJECTIVE

To determine the frequency of antiphospholipid antibodies (aPL) in patients with unexplained articular manifestations.

MATERIAL AND METHODS

Three hundred thirteen patients suffering from arthritis or arthralgia without evident cause and 266 healthy blood donors (HBD) were included in the study. Anticardiolipin antibodies (aCL) and anti-beta 2-glycoprotein I antibodies (aβ2GPI) were measured by ELISA.

RESULT

Out of the 313 patients, 250 were females and 63 were males. The mean age of patients was 49 ± 14 years (17-87 years). One hundred eleven patients have arthralgia and 202 have arthritis. The frequency of aCL and/or aβ₂ GPI (24.9%) was significantly higher in patients than in HBD (10.9%). The frequency of aβ2GPI was 23.6% in patients and 9.4% in the control group (p < 10^-3 ). aβ2GPI-IgA was significantly more frequent in patients than in the control group (20.4% vs. 7.5%, p < 10^-3 ). aβ2GPI was most commonly observed than aCL in patients (23.6% vs. 6.4%, p < 10^-6 ). IgA isotype of aβ2GPI was the most frequent in 20.4% of patients while IgG and IgM were detected in 5.4% and 2.9% respectively.

CONCLUSION

This study showed that aPL were common in patients with articular manifestations and were mainly directed against β₂ GPI. The role of these antibodies remains to be specified.