POS1215 IMMUNE CORRELATES AND CLINICAL COURSE OF PATIENTS WITH RHEUMATOID ARTHRITIS FOLLOWING VACCINATION WITH ANTI SARS-CoV-2 mRNA BASED VACCINES: RESULTS FROM A PROSPECTIVE, OBSERVATIONAL AND CONTROLLED STUDY

Background

Vaccines are highly effective in preventing COVID-19 associated hospitalization and deaths. Strong and persistent immune responses are critical to provide protection for patients with immunomodulatory therapies.

Objectives

To assess humoral and cellular immune responses following 2 doses of an anti-SARS-CoV-2 mRNA based vaccine in rheumatoid arthritis (RA). Immune responses in patients treated with csDMARDs, bDMARDs (with the exception of rituximab) and JAK inhibitors were compared to healthy controls (HC) over 24 weeks. In addition, disease activity by CDAI and vaccine-induced side effects were prospectively monitored.

Methods

The RECOVER trial (Rheumatoid Covid-19 Vaccine Immune Response) is a non-randomised, prospective observational control group trial and enrolled 77 RA patients on DMARD therapy and 21 HC. Clinical assessment and blood sampling was performed at baseline, 3 weeks after the 1st and 2 weeks after the 2nd vaccine dose and at week 12 and 24 after the 1st. Antibody response to the receptor binding domain (RBD) within the SARS-CoV-2 S1 protein was measured with the Elecsys Anti-SARS-CoV-2-S (Roche Diagnostics GmbH) test. The seroprofiling assay ABCORA, which has been suggested as a surrogate for neutralization,1 was used to determine IgG, IgA and IgM responses to RBD, S1, S2 and N. The neutralizing activity NT50 at week 12 was assessed against Wuhan-Hu-1 pseudoviruses (HIV-based). IFN-y ELISpots were applied to detect spike-reactive T cell responses after in vitro stimulation with a spike peptide mix.

Results

Baseline characteristics of participants are detailed in Table 1. Vaccination was well tolerated with no differences between RA patients and HC. At baseline, the majority of RA patients were in remission/LDA (57/77, 74%), this proportion decreased to 51% (39/77) after the second vaccine dose (p = 0.005). Treatment adjustments were required in 11/77 patients. The immunogenicity analyses were based on 73 RA patients after exclusion of 4 patients with previously unnoticed SARS-CoV-2 infection (positive for anti-nucleoprotein). In contrast to HC, anti-S titers were lower at all timepoints with significantly reduced titers observed in patients on abatacept and JAK inhibitors (Figure 1). Potent neutralizing activity (NT50 ≥ 250)) was detected in all HC at week 12, in contrast to 62% RA patients. NT50 correlated to the results based on the ABCORA assay. Peak anti-S titers (2 weeks after 2nd vaccine) were predictive of NT50 ≥ 250 at week 12 (p < 0.0001). In contrast to marked differences in the humoral immune responses, spike-protein specific IFN-α secreting T cells were largely unaltered by different DMARD regimen.

Table 1.

Baseline characteristics

RA patients (n = 77)HC (n = 21)p-valueAge (yrs), mean (± SD)64 (13)44 (14)< 0.0001Female, n (%)46 (60)15 (71)NSVaccination typemRNA-1273, n (%)12 (16)0 (0)0.06BNT162b2, n (%)65 (84)21 (100)Disease activity (CDAI)Remission (≤ 2.8), n (%)17/77 (22)Low (2.9 - 10), n (%)40/77 (52)Moderate (10.1 - 22.0), n (%)15/77 (20)High (22.1 - 76.0), n (%)5/77 (7)DMARD therapyMono csDMARDs, n (%)22/77 (29)bDMARDs, n (%)35/77 (46)Mono bDMARDs, n (%)14/35 (40)JAKi, n (%)20/77 (26)Mono JAKi, n (%)8/20 (40)Prednisone, n (%)25/77 (33)Mean daily dose (mg ± SD)5.6 ± 3.6

Conclusion

RA patients, in comparison with HC, revealed a slower kinetic and lower magnitude of humoral immune responses depending on the treatment regimen while T cell responses were largely maintained. Peak anti-S responses two weeks after the second vaccine were able to predict the development of potent neutralizing activity and should therefore be considered to individually tailor vaccination strategies.

References

[1]Abela I et al. Nature Commun 2021. doi.org/10.1038/s41467-021-27040-x

Disclosure of Interests

Kristin Schmiedeberg: None declared, Irene A. Abela: None declared, Natalia Barbara Pikor: None declared, Nicolas Vuilleumier: None declared, Magdalena Schwarzmueller: None declared, Selina Epp: None declared, Sabrina Pagano: None declared, Sarah Grabherr: None declared, Angelica Brooke Patterson: None declared, Madalina Nussberger: None declared, Alexandra Trkola: None declared, Burkhard Ludewig: None declared, Johannes von Kempis: None declared, Andrea Rubbert-Roth Speakers bureau: Abbvie, Pfizer, Sanofi, UCB, BMS, Lilly, Gilead, Roche, Consultant of: Abbvie, Gilead, Lilly, BMS, Sanofi

OP0175 TYPE OF mRNA COVID-19 VACCINE AND TREATMENT INFLUENCE ANTIBODY KINETICS IN PATIENTS WITH INFLAMMATORY RHEUMATIC DISEASES

Background

Patients on immunomodulatory treatments mount an attenuated immune response following mRNA COVID-19 vaccination, yet long-term studies of vaccine-induced anti-SARS-CoV-2 antibody (Ab) kinetics are missing.

Objectives

In this prospective observational study, we mapped the humoral antibody response to mRNA COVID-19 vaccines up to 24 weeks post full vaccination in patients with inflammatory rheumatic diseases (IRDs). We aimed to assess differences due to treatment, age, past SARS-CoV-2 infection, and vaccine (BNT162b2 vs. mRNA-1273).

Methods

Adult patients from the SCQM cohort who assented to an mRNA COVID-19 vaccine were recruited between 3/21 – 9/21. Participants answered questionnaires via an app and received kits for the self-collection of capillary blood samples at baseline, 4, 12, and 24 weeks post full vaccination. Samples were tested for IgG Ab against the S1 domain of the SARS-CoV-2 spike protein (anti-S1-IgG) using the EUROIMMUN ELISA. To examine differences in Ab titres arising from the defined parameters, while accounting for inter-assay variability, mixed effects continuous outcome logistic regression models were applied at each timepoint.

Results

Samples were obtained from 570 patients: 67% female, mean age 53 y (SD 12 y) with 37% RA, 36% axSpA, 21% PsA, and 6% UA (undifferentiated arthritis), on no medication (no DMARDs & no glucocorticoids; 15%), csDMARDs (10%), TNFi (48%), IL-1/6/17/23i (14%), JAKi (6%), rituximab (RTX; 4%), or abatacept (ABA; 2%) in mono/combination therapy at the first vaccination. 10% of patients had a past SARS-CoV-2 infection, 54% received BNT162b2, 46% mRNA-1273.

For any Ab threshold, the odds of having a higher Ab titre at 4, 12, and 24 weeks post full vaccination were 3.3 – 4 times higher with mRNA-1273 compared to BNT162b2 (Table 1, Figure 1). TNFi, JAKi, RTX, and ABA as monotherapy resulted in significantly lower Ab levels compared to no medication at almost all timepoints. In combination therapy, TNFi, IL-1/6/17/23i, RTX, and csDMARDs led to consistently lower Ab titres at all timepoints compared to respective monotherapy.

Table 1.

The OR of being above a given Ab threshold, regardless of the threshold. Ref. levels: mean age, no medication, no past SARS-CoV-2 inf., BNT162b2. Included in model but not shown: diagnosis, infrequently used medication (all non-signif.)

Weeks post full vacc.41224OR (95% CI); pAge0.96 (0.94 – 0.97)****0.98 (0.96 – 0.996)*0.98 (0.97 – 1.00)mRNA-1273 (vs BNT162b2)3.28 (2.34 – 4.61)****3.96 (2.83 – 5.54)****3.94 (2.93 – 5.50)****Past COVID inf. (vs none)7.56 (4.32 – 13.2)****8.14 (4.78 – 13.86)****11.65 (6.62 – 20.50)****csDMARD†1.27 (0.67 – 2.41)1.78 (0.94 – 3.35)1.70 (0.86 – 3.36)TNFi†0.46 (0.28 – 0.71)****0.30 (0.19 – 0.48)****0.13 (0.081 – 0.22)****IL-1/6/17/23i†0.97 (0.54 – 1.75)1.04 (0.57 – 1.89)0.89 (0.49 – 1.64)JAKi†0.38 (0.16 – 0.91)*0.38 (0.16 – 0.91)*0.53 (0.22 – 1.28)RTX†0.078 (0.013 – 0.46)**0.078 (0.015 – 0.42)**0.16 (0.037 – 0.71)*ABA†0.14 (0.039 – 0.51)**0.087 (0.022 – 0.35)***0.068 (0.017 – 0.27)***Interactions§Age:vaccine‡1.04 (1.02 – 1.07)**1.02 (0.99 – 1.05)1.03 (1.0008 – 1.058)*csDMARD:combi0.12 (0.02 – 0.70)*0.17 (0.029 – 0.95)*0.11 (0.023 – 0.56)**TNFi:combi0.34 (0.20 – 0.59)***0.37 (0.22 – 0.61)***0.36 (0.21 – 0.62)***IL-1/6/17/23i:combi0.26 (0.09 – 0.78)*0.25 (0.085 – 0.70)**0.20 (0.071 – 0.58)**JAKi:combi1.76 (0.33 – 9.44)1.23 (0.32 – 4.70)0.95 (0.25 – 3.65)RTX:combi0.11 (0.01 – 0.87)*0.095 (0.012 – 0.73)*0.085 (0.0091 – 0.79)*ABA:combi1.75 (0.25 – 12.2)0.74 (0.096 – 5.75)0.51 (0.073 – 3.62)

* p < 0.05; ** p < 0.01; *** p < 0.001; **** p < 0.0001;

†Medication as monoth. vs no medication

‡Interaction terms showing how OR of mRNA-1273 (vs BNT162b2) increases with age

§Interaction terms with medications: medication in combination th. vs medication as monoth.

Conclusion

Compared to no medication, some immunomodulatory therapies resulted in markedly lower Ab levels at all timepoints. In IRD patients, a past SARS-CoV-2 infection resulted in strikingly increased immunogenicity, as did mRNA-1273 compared to BNT162b2.

Acknowledgements

This study is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM thanks the patients for their participation in this study. A list of rheumatology offices and hospitals that contribute to the SCQM registries can be found on www.scqm.ch/institutions. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors.

Disclosure of Interests

Catherine Elizabeth Raptis Grant/research support from: The study presented in the abstract is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors, Diego Olivier Andrey: None declared, Christos Polysopoulos Grant/research support from: The study presented in the abstract is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors, Christoph Berger: None declared, Adrian Ciurea: None declared, Pierre Lescuyer: None declared, Tanja Maletic Grant/research support from: The study presented in the abstract is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors, Myriam Riek Grant/research support from: The study presented in the abstract is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors, Almut Scherer Grant/research support from: The study presented in the abstract is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors, Isabell von Loga Grant/research support from: The study presented in the abstract is investigator-initiated and received independent financial support from Moderna Switzerland GmbH. The SCQM is financially supported by pharmaceutical industries and donors. A list of financial supporters can be found on www.scqm.ch/sponsors, Judith Safford: None declared, Kim Lauper Speakers bureau: Kim Lauper reports consulting fees for Pfizer and speakers fees for Pfizer, Viatris and Celltrion outside of the submitted work., Consultant of: Kim Lauper reports consulting fees for Pfizer and speakers fees for Pfizer, Viatris and Celltrion outside of the submitted work., Burkhard Moeller: None declared, Nicolas Vuilleumier: None declared, Axel Finckh Speakers bureau: Axel Finckh has received consultancies or speaker honoraria for AbbVie, BMS, Eli-Lilly, Gilead, Pfizer, Sanofi, and UCB outside of the submitted work, Consultant of: Axel Finckh has received consultancies or speaker honoraria for AbbVie, BMS, Eli-Lilly, Gilead, Pfizer, Sanofi, and UCB outside of the submitted work, Grant/research support from: Axel Finckh has received research support from AbbVie, Eli-Lilly, Galapagos, and Pfizer outside of the submitted work, Andrea Rubbert-Roth: None declared

POS1277 LONGTERM IMMUNOGENICITY AND TOLERABILITY OF A 3RD DOSE OF AN mRNA ANTI-SARS-CoV-2 VACCINE IN RA PATIENTS WITH AN INADEQUATE RESPONSE TO A PREVIOUS STANDARD TWO DOSE REGIMEN

Background

Lower seroconversion rates have been reported in patients with rheumatic diseases receiving immunomodulatory therapies following a standard mRNA-based vaccine regimen. Data with regard to immunogenicity and safety of a 3rd vaccine dose in this patient population is limited1.

Objectives

We aim to study immunogenicity, vaccine associated side effects and the occurrence of flares in RA patients unresponsive to a standard vaccine regimen eligible for a 3rd vaccine dose.

Methods

RA patients who had a low or absent anti-S1 response after 12 (Cohort A) or 24 weeks (Cohort B) following a standard vaccination regimen received a 3rd vaccine dose. Temporary discontinuation of DMARD therapy was recommended. Serum samples were collected before, 2, 12, and 24 weeks after the 3rd vaccine dose. Quantitative measurement of anti-S was performed using the Roche Elecsys Anti-SARS-CoV-2 spike subunit assay. Neutralizing activity (NT50) against Wuhan WT and αasβ-, γ-, and δ- variants was assessed by using a HIV-based pseudovirus system.

Results

Baseline characteristics are shown in Table 1. 45/47 patients temporarily discontinued DMARD therapy: Mtx and JAKi were paused one 1 week before/restarted 2 weeks after the 3rd vaccine dose, bDMARDs were paused 2 weeks before/restarted 2 weeks after the 3rd dose. Local pain and/or systemic vaccine associated side effects following the 3rd vaccine dose were reported in 12/17 (71%) in Cohort A, and 10/29 (35%) patients in Cohort B (p = 0.018). Flares were defined as loss of low disease activity (LDA), subsequent to the 3rd vaccine dose and occurred in 17/47 (36%) patients (p = 0.0332) with comparable frequencies in both cohorts (41% Cohort A, 33% Cohort B (NS)).

Table 1.

Baseline characteristics of RA patients in Cohort A and Cohort B

RA patients (n = 17) Cohort ARA patients (n = 30) Cohort Bp-valueAge (yrs), mean (± SD)69 (8)63.9 (8)NSFemale sex, n (%)9 (53)13 (43)NSVaccination type/schedulemRNA-1273/BNT162b2, n=3/145/25NSRA disease characteristicsACPA ± RF, n (%)13 (77)12 (40)0.02*Disease activity (CDAI)Remission (≤ 2.8), n (%)3 (18)6 (20)NSLDA (2.9 - 10), n (%)11 (64)18 (60)NSModerate CDAI (10.1 - 22.0), n (%)2 (12)3 (10)NSHigh CDAI (22.1 - 76.0), n (%)1 (6)3 (10)NSDMARD therapyNSMonotherapy of csDMARDs, n (%)2/17 (12)10/30 (33)NSbDMARDs ± csDMARDs, n (%)8/17 (47)14/30 (47)NSJAKi ± csDMARDs, n (%)7/17 (41)6/30 (20)NSPrednisone, n (%)5/17 (29)11/30 (37)NSMean daily dose prednisone (mg ± SD)4.1 ± 1.64.1 ± 1.5NS

Low or absent anti-S titers were confirmed before the third vaccination (Cohort A: median 19.5 U/ml, IQR 0.47-57; cohort B: median 65.9 U/ml, IQR 22-154) (p = 0.0018). Two weeks after the 3rd dose, a rapid and significant increase in anti-S were observed in 12/17 (82%) and 25/28 (89%) patients (Cohort A: median 2500 U/ml, IQR 798-2500; Cohort B: median 2500 U/ml, IQR 2500-2500) (NS). High levels of anti-S were maintained in the majority of patients 55% (11/20) until week 12 in both cohorts (Figure 1). NT50 against Wuhan-WT and other variants was assessed in 21 patients 2 weeks after the 3rd vaccine dose revealing a low or absent NT50 against delta in 38% of patients despite a median anti-S response of 2500 U/ml (IQR 798-2500). 14/21 patients had peak anti-S titres of 2500 U/ml, of those 12/14 developed a strong NT50 response against the delta variant.

Figure 1.

Conclusion

Our data demonstrate that a 3rd vaccine dose, maybe complimented by temporary discontinuation of DMARD therapy, may lead to a rapid increase in anti-S antibodies when using a homologous vaccine and profound neutralizing activity in the majority of RA patients previously unresponsive to a standard two dose regimen. This seems to be independent of the interval to the previous standard vaccine regimen. As flares occurred in 36% of all patients, the necessity and length of DMARD discontinuation should be explored in more detail to balance between sustained control of disease activity and optimized vaccine induced immune responses.

References

[1]Schmiedeberg K, et al. Lancet Rheumatol 2022; 4(1): e11-e13

Disclosure of Interests

Kristin Schmiedeberg: None declared, Irene A. Abela: None declared, Nicolas Vuilleumier: None declared, Sabrina Pagano: None declared, Johannes von Kempis Speakers bureau: Lilly, Consultant of: Abbvie, BMS, Pfizer, and Sanofi, Andrea Rubbert-Roth Speakers bureau: Abbvie, Pfizer, Sanofi, UCB, BMS, Lilly, Gilead and Roche, Consultant of: Abbvie, Gilead, Lilly, BMS, and Sanofi

Autoantibodies directed against apolipoprotein A-1 as a potential contributor to non-alcoholic fatty liver disease

Background

Non-Alcoholic Fatty Liver Disease (NAFLD) represents an increasing cause of liver disease worldwide. Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in these patients. Although NAFLD pathophysiology is not fully understood alterations in fat metabolism seem to play a role. Autoantibodies against apolipoprotein A-1 (anti-apoA-1 IgG) are a novel cardiovascular risk factor to which have been recently attributed a metabolic role in addition to a well-established macrophage-mediated inflammatory effect and have a function as a disruptor of the cholesterol pathway.

Purpose

This study aims at evaluating a possible role of anti-apoA-1 IgG in NAFLD.

Methods

Serum from 137 NAFLD patients were tested for anti-apoA-1 IgG prevalence. In vitro, SREBP1, SREBP2 expressions were assessed in the human hepatic cell line HepaRG by western blot analysis and bodipy staining was used to evaluate the lipid droplet content. Mescoscale technology platform was used to measure TNF-α, IL-6 and IL-8 cytokines/chemokines in HepaRG supernatants. Oil Red O staining was used to detect lipid accumulation in liver sections from ApoE−/− mice.

Results

Elevated anti-apoA-1 IgG seropositivity was found in patients with NAFLD (46%). In vitro, anti-apoA-1 IgG and not control IgG induced lipid accumulation in hepatic cells (5.9 vs 2.5, P=0.0008) and this lipid overload was associated with a high SREBP1 but not SREBP2 expression. Furthermore, anti-apoA-1 IgG and not control antibodies caused a significant large increase of the proinflammatory cytokines IL-6 (680 vs. 163 pg/mL, P=0.03) and TNF-α (391 vs 266 pg/mL, P=0.04) as well as of the chemokine IL-8 (174.1 vs. 72.6 ng/mL, P=0.03) detected in the hepatic cell supernatants. In vivo, anti-apoA-1 IgG and not control IgG also induced higher lipid accumulation in the livers of ApoE−/− mice (1.23 vs 0.53, P=0.03).

Conclusion

Anti-apoA-1 IgG are frequent in NAFLD, cause a strong inflammatory response and promote lipid accumulation through SREBP1 activation in human hepatic cells. We hypothesize that anti-apoA1 IgG may be a potential contributor in the development of NAFLD.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Geneva University Hospital

Sars-CoV2- infection as a trigger of humoral response against apolipoprotein A-1

Background

Unravelling autoimmune targets triggered by SARS-CoV-2 infection may provide crucial insights in the physiopathology of the disease and foster the development of potential therapeutic candidate targets and prognostic tools. SARS-CoV-2 autoimmune-mediated inflammation have been reported, but the existence of autoantibodies against apolipoprotein A-1 (anti-apoA-1 IgG) in COVID-19 remains unexplored. Anti-apoA-1 IgGs have emerged as an independent biomarker for cardiovascular disease and mortality in humans with proinflammatory and proatherogenic functions in vivo and in vitro.

Purpose

We want to determine i) the degree of homology between SARS-CoV-2, apoA-1, and Toll-like receptor-2 (TLR2) epitopes, ii) the association between anti-SARSCoV2 and anti-apoA-1 IgGs, and iii) their relationship to prognosis.

Methods

We performed bioinformatics modelling coupled with mimetic peptides engineering, as well as functional and competition assays with antibodies to identify molecular mimicry between SARS-CoV-2, apoA-1 and TLR2 epitopes. Anti-Spike domain 1 (SD1) IgGs, anti-apoA-1 IgGs and against mimic peptides, as well as cytokines were assessed by immunoassays on a case-control (n=101), an intensive care unit (ICU; n=126) with a 28-days follow-up for overall mortality, and a general population cohort (n=663) with available samples in the pre and post-pandemic period.

Results

Linear sequence homologies and antibodies cross-reactivity between apoA-1, TLR2, and Spike epitopes were identified. Overall, anti-apoA-1 IgG levels were higher in COVID-19 patients or anti-SARS-CoV-2 seropositive individuals than in healthy donors or anti-SARS-CoV-2 seronegative individuals (p&lt;0.0001). Significant and similar associations were noted between anti-apoA-1, anti-SARS-CoV-2 IgG, cytokines, and lipid profile. In ICU patients, anti-SARS-CoV-2 and anti-apoA-1 seroconversion rates displayed similar 7-days kinetics, reaching 82% for anti-apoA-1 seropositivity. C-statistics (CS) indicated that baseline anti-Spike/TLR2 mimic-peptide IgGs displayed a significant prognostic accuracy for overall mortality at 28 days (CS: 0.64; p=0.02). In the general population, SARS-CoV-2 exposure increased baseline anti-apoA-1 IgG levels.

Conclusions

COVID-19 induces a marked humoral response against the major protein of high-density lipoproteins. As a correlate of poorer prognosis in other clinical settings, such autoimmunity signatures may relate to long-term COVID-19 prognosis assessment and warrant further scrutiny in the current COVID-19 pandemic.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): This study was funded by the Swiss Federal Office of Public Health, Swiss School of Public Health (Corona Immunitas research program), the Fondation de Bienfaisance du Groupe Pictet, the Fondation Ancrage, the Fondation Privée des HUG, and the Center for Emerging Viral Diseases. The De Reuter (grant Nr 657) and the Schmidheiny Foundation.

HIV-infected patients display increased proatherogenic anti-apolipoprotein A1 autoantibodies, inflammatory and metabolomic markers

Background

HIV-infected patients display an increased risk of cardiovascular events. HIV and antiretroviral therapy (ART) have both been suggested to increase this risk but their specific role remains unclear. Autoantibodies against apolipoprotein A1 (anti-apoA1 IgG) are also associated with cardiovascular risk. The aim of this study was to analyse anti-apoA1 IgG levels and inflammatory markers as well as the metabolomic profile in a cohort of HIV-free, ART-experienced and naïve HIV-infected patients.

Methods

144 participants from a South African cohort were categorised into HIV-free (n=50), HIV-infected/ART-experienced (n=50) and HIV-infected/ART-naïve (n=44) groups. The levels of anti-apoA1 IgG were assessed by homemade ELISA assays. We performed targeted metabolomic analyses using standard operating procedures and measured inflammatory biomarkers using the Meso Scale Discovery® platform. Additionally, we conducted in vitro experiments on human aortic endothelial cells treated with anti-apoA1 IgG and assessed levels of adhesion molecules.

Results

Inflammatory markers (IFNg, IL-6, IL-10, TNFa, CRP all p&lt;0.05), circulating adhesion molecules (ICAM-1 and VCAM-1, p&lt;0.05), anti-apoA1 IgG levels were increased in HIV-infected patients compared to HIV-free participants.

While ART treatment significantly reduced IFNg, IL-10, TNFa, VCAM-1, anti-apoA1 IgG levels, no significant differences were observed in other biomarkers between ART-experienced and naïve participants. Treatment of human aortic endothelial cells with anti-apoA1 IgG (40μg/ml) induced a significant increase in these adhesion molecules compared to cells treated with control IgG (40μg/ml). Metabolomic analyses identified 257 endogenous circulating metabolites in plasma. Among these metabolites, we found that in HIV-free and infected patients 14 and 17 metabolites were significantly correlated with anti-apoA1 IgG levels, respectively. Among these 17 metabolites, 2 were positively correlated with the tryptophan pathway; kynurenine (r=0.292, p=0.0069) and 5-hydroxyindolacetate (r=0.316, p=0.0019). Interestingly, kynurenine was not significantly correlated with anti-apoA1 IgG levels in HIV-free patients.

Conclusion

HIV-infected patients displayed a more proatherogenic profile compared to HIV-free subjects. Anti-apoA1 IgG induced adhesion molecules expression. Metabolomics identified metabolites that were significantly associated with anti-apoA1 IgG levels and inflammatory biomarkers known to underlie atherosclerosis burden.

Funding Acknowledgement

Type of funding sources: None.

Lipoprotein(a) levels are not independently associated with endogenous steroid hormone levels, in contrast to other non-genetic and genetic factors: the population-based SKIPOGH study

Introduction

Lipoprotein(a) [Lp(a)] is an LDL-like molecule that is likely causally related to cardiovascular events. Lp(a) levels are highly variable, by more two orders of magnitude, and most of this variability appears to be of genetic origin. Exogenous hormones (hormone replacement therapy) seem to influence Lp(a) levels, but the impact of the variation of endogenous hormone levels on Lp(a) is unknown.

Purpose

To investigate the association between Lp(a) levels and non-genetic factors, as endogenous steroid hormone levels, in contrast to genetic factors.

Methods

We investigated the association of 28 endogenous steroids with Lp(a) levels and compared the association to other non-genetic and genetic variables in a prospective, population-based sample (N=1,021).

Results

The average age of the participants was 51 years and 53% were female. Median Lp(a) levels were 62 (±204) mg/l and the 90th and 99th percentile of Lp(a) was 616mg/l and 1035 mg/l respectively. The prevalence of a Lp(a) elevation ≥700mg/l was 3.2% and Lp(a) varied greatly from undetectable to 1,690mg/l. Age explained 2.0% of Lp(a) variability (p&lt;0.001), 1% was explained by LDL levels (p=0.001), and 40% by two single nucleotide polymorphisms near the Lp(a) gene that have been previously described. Lp(a) levels were on average almost two times more elevated in secondary prevention and in individuals with very elevated LDL levels (≥4.9 mmol/l). Of the 28 endogenous steroid hormones assessed, 5-androstene-3b,16α,17β-triol, androsterone, 16α-hydroxy DHEA, and estriol were nominatively associated with serum Lp(a) levels and explained 0.4–1% of Lp(a) variability in univariate analyses, but they did not reach significance in multi-variate models.

Conclusion

Our results confirm previous findings demonstrating that the majority of the Lp(a) variation in the general population is of genetic origin. Age and LDL-levels explain a further small part of Lp(a) variability. Endogenous hormone levels do not contribute significantly to the wide range of variability.

Funding Acknowledgement

Type of funding sources: None. Coefficient plot Lp(a) and variables

Evaluation of antiretroviral therapy on metabolomics and atherogenic markers in HIV patients

Background

HIV-infected patients display an increased risk of cardiovascular events. HIV and antiretroviral therapy (ART) have both been suggested to increase the risk of cardiovascular events but their specific role remains unclear.

Purpose

The aim of this study was to analyse the metabolomic profile in a cohort of HIV-free, ART experienced and naïve HIV-infected patients and to identify the metabolite associated with atherosclerosis development and endothelial dysfunction. The impact of ART on inflammatory and autoimmune biomarkers known to underlie atherosclerosis burden was also investigated.

Methods

144 participants from a South African cohort were divided in three groups: HIV-free (n=50), HIV-infected/ART experienced (n=50) and HIV-infected/ART naïve (n=44). Targeted metabolomic analyses were performed using standard operating procedures. Atherosclerosis development was evaluated using coronary intima-media thickness (CITM) and endothelial dysfunction by flow-mediated dilation (FMD). Inflammatory biomarkers were measured with the Meso Scale Discovery® platform. The levels of autoantibodies against apolipoprotein A1 (anti-apoA1 IgG) and its specific C-terminal domain (anti-F3L1) levels were assessed by homemade ELISA assays.

Results

257 endogenous metabolites were identified in the 144 samples. Regarding the association of metabolites with the vascular markers, eight metabolites were found to be associated with FMD and eleven with CIMT. Among these metabolites, cytosine was negatively correlated with FMD (r=−0.22, p=0.009), while positively with CIMT (r=0.20, p=0.026). Interestingly, from the list of these 18 metabolites, ART-experienced patients displayed an increase in kynurenine (p=0.0007) and 3–2-hydroxyphenyl-propanoate (p=0.0009) levels and a decrease in itaconate (p=0.021) levels compared to ART-naïve patients. HIV-infected patients displayed a more proatherogenic profile compared to HIV-free subjects. Inflammatory markers (IFNg, IL-6, IL-10, TNFα, CRP all p&lt;0.05), circulating adhesion molecules (ICAM-1 and VCAM-1, p&lt;0.05), anti-apoA1 IgG and anti-F3L1 (p&lt;0.05) and CIMT (p=0.05) were increased while FMD (p=0.054) was decreased in HIV-infected patients compared to HIV-free participants. While ART treatment significantly reduced IFNg, IL-10, TNFα, VCAM-1, anti-apoA1 IgG and anti-F3L1, no significant differences were observed in other biomarkers between ART-experienced and naïve participants.

Conclusion

Metabolomic analysis identified metabolites that were differentially expressed in the 3 groups. 18 metabolites were significantly correlated with FMD or CITM, among which the levels of kynurenine, 3–2-hydroxyphenyl-propanoate and itaconate were modulated by ART. HIV patients displayed increased levels of inflammatory markers, circulating adhesion molecules and anti-apoA1 IgG which was downregulated by ART.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Fondation De Reuter; Fondation Schmidheiny; Fondation Prévot; SwissLife AG; Fondation pour la lutte pour le cancer et la recherche bio-médicale

Antibodies against the c-terminus of apoA-1 as predictors of death in the general population but not as therapeutic targets actionable through cognate peptides immunomodulation

Aims

Autoantibodies against apolipoprotein A-1 (anti-apoA-1 IgGs) have emerged as an independent biomarker for cardiovascular disease and mortality in humans, promote death in ApoE−/− mice, and seem to be preferentially oriented against the c-terminal part of apoA-1 (cterA1). Corresponding specific mimetic peptides were shown to reverse anti-apoA-1 IgG pro-inflammatory effects in vitro. We evaluated the association of IgG against c-terminus apoA-1 (anti-cterA1 IgGs) with all-cause mortality in the community and tested the ability of two cterA1 mimetic peptides to reverse the anti-apoA-1 IgG-induced inflammation in vitro and mortality in ApoE−/− mice.

Methods

Anti-cterA1 IgGs were measured on serum samples of 5220 consecutive participants included in the CoLaus study with median follow-up duration of 5.6 years. The primary study outcome was all-cause mortality. Two chemically engineered optimized cterA1 mimetic peptides were tested i) on HEK cells to modulate interleukin-8 (IL-8) and tumor necrosis-alpha (TNF-α) production, and ii) in apoE−/− mice exposed to 16 weeks of anti-apoA-1 IgG passive immunisation.

Results

Anti-cterA1 IgG independently predicted all-cause mortality, each standard deviation of anti-cterA1 IgG being associated with a 18% increase in mortality risk (Hazard Ratio:1.18, 95%confidence intervals:1.04–1.33; p=0.009). Both cterA1 mimetic peptides reduced the anti-apoA-1 IgG-induced inflammation in a dose-dependent manner in vitro, but did not rescue the anti-apoA-1 IgG-associated mortality in mice.

Conclusions

Anti-cterA1 IgG independently predict all-cause mortality in the general population. By failing to reverse the anti-apoA-1 IgG-induced mortality in mice, our data do not support the hypothesis that these autoantibodies could be actionable through cognate peptides immunomodulation.

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by a grant from the Leenaards Foundation (grant number 3698 to N.V.) by the Swiss National Science Foundation (grant number 310030-163335 to N.V.) and by the De Reuter Foundation (grant number 315112 to N.V.).

Validation of a commercially available SARS-CoV-2 serological immunoassay

OBJECTIVES

To validate the diagnostic accuracy of a Euroimmun SARS-CoV-2 IgG and IgA immunoassay for COVID-19.

METHODS

In this unmatched (1:2) case-control validation study, we used sera of 181 laboratory-confirmed SARS-CoV-2 cases and 326 controls collected before SARS-CoV-2 emergence. Diagnostic accuracy of the immunoassay was assessed against a whole spike protein-based recombinant immunofluorescence assay (rIFA) by receiver operating characteristic (ROC) analyses. Discrepant cases between ELISA and rIFA were further tested by pseudo-neutralization assay.

RESULTS

COVID-19 patients were more likely to be male and older than controls, and 50.3% were hospitalized. ROC curve analyses indicated that IgG and IgA had high diagnostic accuracies with AUCs of 0.990 (95% Confidence Interval [95%CI]: 0.983-0.996) and 0.978 (95%CI: 0.967-0.989), respectively. IgG assays outperformed IgA assays (p=0.01). Taking an assessed 15% inter-assay imprecision into account, an optimized IgG ratio cut-off > 2.5 displayed a 100% specificity (95%CI: 99-100) and a 100% positive predictive value (95%CI: 96-100). A 0.8 cut-off displayed a 94% sensitivity (95%CI: 88-97) and a 97% negative predictive value (95%CI: 95-99). Substituting the upper threshold for the manufacturer's, improved assay performance, leaving 8.9% of IgG ratios indeterminate between 0.8-2.5.

CONCLUSIONS

The Euroimmun assay displays a nearly optimal diagnostic accuracy using IgG against SARS-CoV-2 in patient samples, with no obvious gains from IgA serology. The optimized cut-offs are fit for rule-in and rule-out purposes, allowing determination of whether individuals in our study population have been exposed to SARS-CoV-2 or not. IgG serology should however not be considered as a surrogate of protection at this stage.

Comparison of the Copan WASPLab incorporating the BioRad expert system against the SIRscan 2000 automatic for routine antimicrobial disc diffusion susceptibility testing

OBJECTIVES

This study investigated the agreement at the categorical level between the Copan WASPLab incorporating the BioRad expert system against the SIRscan 2000 automatic for antimicrobial disc diffusion susceptibility testing.

METHODS

The 338 clinical strains (67 Pseudomonas aeruginosa, 19 methicillin-resistant Staphylococcus aureus, 75 methicillin-sensitive S. aureus and 177 Enterobacterales isolates) analysed in this study were non-duplicate isolates obtained from consecutive clinical samples referred to the clinical bacteriology laboratory at Geneva University Hospitals between June and August 2019. For the WASPLab the inoculum suspension was prepared in strict accordance with the manufacturer's instruction (Copan WASP srl, Brescia, Italy) by adding 2 mL of the 0.5 McFarland primary suspension used for the SIRscan analysis into a sterile tube filled with 4 mL of sterile saline (1:3 dilution). The inoculum (2 × 30 μL loop/spreader) was spread over the entire surface of Mueller-Hinton agar plates according to the AST streaking pattern defined by Copan. The antibiotic discs were dispensed by the WASP and inoculated media were loaded on conveyors for transfer to the automatic incubators. The plates were incubated for 16 h, and several digital images were acquired. Inhibition zone diameters were automatically read by the WASPLab and were adjusted manually whenever necessary. For the SIRscan 2000 automatic, the antimicrobial disc diffusion susceptibility testing was performed according to the EUCAST guidelines. The gradient strip method was used to resolve discrepancies.

RESULTS

The overall categorical agreement between the compared methods reached 99.1% (797/804; 95% CI 98.2%-99.6%), 99.5% (1029/1034; 95% CI 98.9%-99.8%), and 98.8% (2798/2832; 95% CI 98.3%-99.1%) for P. aeruginosa, S. aureus and the Enterobacterales, respectively.

CONCLUSIONS

WASPLab incorporating the BioRad expert system provides a fully automated solution for antimicrobial disc diffusion susceptibility testing with equal or better accuracy than other available phenotypic methods.

P5343The presence of anti-apolipoprotein A1 autoantibodies is associated with a pro-atherogenic profile in HIV-infected patients

Background

With the access to antiretroviral therapy (ART), the mortality related to the human immunodeficiency virus (HIV) has dropped, shifting the clinical challenges towards chronic disease management, including cardiovascular disease (CVD) risk assessment. Factors that potentially contribute to the physiopathology of HIV-related CVD include the HI-virus itself, adverse effects of ART, and processes such as dyslipidemia, inflammation, immune/autoimmune activation and endothelial injury. Among autoantibodies of possible cardiovascular relevance, those directed against apolipoprotein A-1 (anti-apoA-1 IgG) were shown to predict major adverse cardiovascular events and promote atherogenesis.

Purpose

The aim of the study was to evaluate the prevalence of anti-apoA1 IgG in HIV-free and ART experienced and naïve HIV-infected patients as well as the association between anti-apoA1 IgG levels and, indices of viral suppression, clinical parameters (10 year Framingham Risk Score (FRS)) and inflammatory biomarkers, known to underlie atherosclerosis burden in these patients.

Methods

Anti-apoA1 IgG serum levels were assessed by a homemade ELISA assay in 144 participants from a South African cohort divided in three groups: HIV-free (n=50), HIV-infected/ART experienced (n=50) and HIV-infected/ART naïve (n=44). Inflammatory biomarkers were measured.

Results

HIV-infected patients displayed an increased pro-atherogenic biomarker profile compared to HIV-free subjects, but not difference in the FRS was observed between these two groups. Regarding anti-apoA1 IgG, 24% of HIV-free patients tested positive compared to 40% and 70% in HIV-infected/ART experienced and naïve groups, respectively. HIV-infected, anti-apoA1 IgG positive patients showed a significant decrease in CD4+ counts (p=0.003) and a significant increase in viremia (p=0.0130), mean heart rate (p=0.0243), albuminuria (p=0.0155), pro-inflammatory biomarkers (IFNγ, IL-10, TNFα, MIPα; all p<0.05), circulating levels of intercellular adhesion molecule (ICAM-1) (p=0.0217) and vascular cell adhesion molecule (VCAM-1) (p=0.003) compared to anti-apoA1 IgG negative ones. Of note, while this profile was maintained in HIV-infected/ART experienced, these significant differences were lost in HIV-infected/ART naïve patients. No significant difference in FRS was observed between anti-apoA1 IgG positive vs negative individuals in all groups.

Conclusions

HIV-infected patients presented with an increased prevalence of anti-apoA1 IgG compared to HIV-free subjects. In HIV-infected/ART experienced patients, anti-apoA1 IgG levels were associated with low CD4+ counts, levels of adhesion molecules and pro-inflammatory responses, features associated with increased cardiovascular events. ART highlighted pro-atherogenic differences between HIV-infected anti-apoA1 IgG negative and positive patients.

Copan WASPLab automation significantly reduces incubation times and allows earlier culture readings

OBJECTIVE

The aim was to evaluate whether laboratory automation (inoculation and automated incubation combined with timely defined high-resolution digital imaging) may help reduce the time required to obtain reliable culture analysis results.

METHODS

We compared the results obtained by WASPLab automation against WASP-based automated inoculation coupled to conventional incubation and manual diagnostic on 1294 clinical samples (483 for the derivation set and 811 for the independent validation set) that included urine, genital tract and non-sterile site specimens, as well as ESwabs for screening of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus (MSSA), extended-spectrum beta-lactamases (ESBLs) and carbapenemase-producing Enterobacteriaceae (CPE). We used sequential routine specimens referred to the bacteriology laboratory at Geneva University Hospitals between October 2018 and March 2019.

RESULTS

The detection sensitivity of MRSA and MSSA at 18 hr on WASPLab was 100% (95% confidence interval [CI], 94.48-100.00%). The detection sensitivity of ESBL and CPE at 16 hr on WASPLab was 100% (95% confidence interval [CI], 94.87% to 100.00%). For urine specimens, the similarity was 79% (295/375) between 18 hr and 24 hr of incubation on WASPLab. For genital tract and non-sterile site specimens, the similarity between 16 hr and 28 hr of incubation on WASPLab were 26% (72/281) and 77% (123/159) respectively. Thus, 28 hr was defined as the final incubation time on WASPLab for genital tract and non-sterile site specimens.

CONCLUSIONS

The results of this study show that WASPLab automation enables a reduction of the culture reading time for all specimens tested without affecting performances. Implementing the established and duly validated incubation times will allow appropriate laboratory workflows for improved efficiency to be built.

Cardiac biomarkers and clinical scores for risk stratification in elderly patients with non-high-risk pulmonary embolism

OBJECTIVE

To determine the prognostic accuracy of cardiac biomarkers alone and in combination with clinical scores in elderly patients with non-high-risk pulmonary embolism (PE).

DESIGN

Ancillary analysis of a Swiss multicentre prospective cohort study.

SUBJECTS

A total of 230 patients aged ≥65 years with non-high-risk PE.

MAIN OUTCOME MEASURES

The study end-point was a composite of PE-related complications, defined as PE-related death, recurrent venous thromboembolism or major bleeding during a follow-up of 30 days. The prognostic accuracy of the Pulmonary Embolism Severity Index (PESI), the Geneva Prognostic Score (GPS), the precursor of brain natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) was determined using sensitivity, specificity, predictive values, receiver operating characteristic (ROC) curve analysis, logistic regression and reclassification statistics.

RESULTS

The overall complication rate during follow-up was 8.7%. hs-cTnT achieved the highest prognostic accuracy [area under the ROC curve: 0.75, 95% confidence interval (CI): 0.63-0.86, P < 0.001). At the predefined cut-off values, the negative predictive values of the biomarkers were above 95%. For levels above the cut-off, the risk of complications increased fivefold for hs-cTnT [odds ratio (OR): 5.22, 95% CI: 1.49-18.25] and 14-fold for NT-proBNP (OR: 14.21, 95% CI: 1.73-116.93) after adjustment for both clinical scores and renal function. Reclassification statistics indicated that adding hs-cTnT to the GPS or the PESI significantly improved the prognostic accuracy of both clinical scores.

CONCLUSION

In elderly patients with nonmassive PE, NT-proBNP or hs-cTnT could be an adequate alternative to clinical scores for identifying low-risk individuals suitable for outpatient management.

Pathophysiological role of neutrophils in acute myocardial infarction

The pathogenesis of acute myocardial infarction is known to be mediated by systemic, intraplaque and myocardial inflammatory processes. Among different immune cell subsets, compelling evidence now indicates a pivotal role for neutrophils in acute coronary syndromes. Neutrophils infiltrate coronary plaques and the infarcted myocardium and mediate tissue damage by releasing matrix-degrading enzymes and reactive oxygen species. In addition, neutrophils are also involved in post-infarction adverse cardiac remodelling and neointima formation after angioplasty. The promising results obtained in preclinical modelswith pharmacological approaches interfering with neutrophil recruitment or function have confirmed the pathophysiological relevance of these immune cells in acute coronary syndromes and prompted further studies of these therapeutic interventions. This narrative review will provide an update on the role of neutrophils in acute myocardial infarction and on the pharmacological means that were devised to prevent neutrophil-mediated tissue damage and to reduce post-ischaemic outcomes.

Evidence on the pathogenic role of auto-antibodies in acute cardiovascular diseases

Atherothrombosis is the major determinant of acute ischaemic cardiovascular events, such as myocardial infarction and stroke. Inflammatory processes have been linked to all phases of atherogenesis In particular, the identification of autoimmunity mediators in the complex microenvironment of chronic inflammation has become the focus of attention in both early and advanced atherogenic processes. Auto-antibodies against self-molecules or new epitopes generated by oxidative processes infiltrate atherosclerotic plaques and were shown to modulate the activity of immune cells by binding various types of receptors. However, despite mounting evidence for a pathophysiological role of autoantibodies in atherothrombosis, the clinical relevance for circulating autoantibodies in cardiovascular outcomes is still debated. This review aims at illustrating the mechanisms by which different types of autoantibodies might either promote or repress atherothrombosis and to discuss the clinical studies assessing the role of auto-antibodies as prognostic biomarkers of plaque vulnerability.

Anti-apolipoprotein A-1 autoantibodies as biomarker for atherosclerosis burden in patients with periodontitis

BACKGROUND AND OBJECTIVE

Anti-apolipoprotein A-1 (anti-apoA-1) IgG is a potential marker of atherosclerotic plaque vulnerability and cardiovascular complications. In patients with periodontitis the presence of anti-apoA-1 IgGs in serum and their association with atherosclerosis is unknown.

MATERIAL AND METHODS

One-hundred and thirty subjects with periodontal disease and 46 healthy subjects, matched for age and gender, participated in this study. Anti-apoA-1 IgG, high-sensitivity C-reactive protein (hsCRP) and matrix metalloproteinase (MMP) -2, -3, -8 and -9 were measured in serum samples. An ankle-brachial index (ABI) value below 1.11 served as a surrogate marker of atherosclerosis. Predictive accuracies of biomarkers for abnormal ABI were determined using receiver-operating characteristics curves and logistic regression analyses.

RESULTS

Compared with healthy controls, periodontitis patients showed lower median ABI values (1.10 vs. 1.15; p < 0.0001), a higher prevalence of anti-apoA-1 IgG positivity (23.8% vs. 6.5%; p = 0.009) and higher concentrations of hsCRP (1.62 mg/L vs. 0.85 mg/L; p = 0.02) and MMP-9 (435 μg/mL vs. 283 μg/mL; p < 0.0001). In patients younger than 50 years of age (n = 66), anti-apoA-1 IgG was found to be the best predictor for an abnormal ABI (area under the curve = 0.63; p = 0.03). Anti-apoA-1 IgG positivity increased the risk of having an abnormal ABI (odds ratio = 4.20; p = 0.04), independently of diabetes, smoking and body mass index.

CONCLUSIONS

Anti-apoA-1 IgG positivity and atherosclerosis, as reflected by abnormal ABI, were more prevalent in periodontitis patients than in age- and gender-matched controls. In younger periodontitis patients, anti-apoA-1 IgG was found to be the best predictor of atherosclerosis burden.

Anti-apolipoprotein A-1 IgG in patients with myocardial infarction promotes inflammation through TLR2/CD14 complex

OBJECTIVES

Toll-like receptor (TLR)-mediated vascular inflammation, inducible by - amongst other factors - auto-antibodies, is increasingly recognized as a potential mediator of cardiovascular disease. We investigated whether anti-apolipoprotein (Apo)A-1 IgG was associated with a pro-inflammatory cytokine profile in myocardial infarction (MI) patients and whether anti-ApoA-1 IgG elicited a pro-inflammatory response by activating TLRs.

METHODS

As surrogate markers of atherosclerotic plaque vulnerability, interleukin (IL)-6, tumour necrosis factor (TNF)-α, matrix metalloproteinase (MMP)-9 and MMP-3 levels were assessed in 221 consecutive MI patients. Using human monocyte-derived macrophages (HMDMs) we investigated (i) the anti-ApoA-1 IgG interaction with TLRs using proximity ligation assay and (ii) anti-ApoA-1 IgG-dependent IL-6/TNF-α production. TLR involvement was further confirmed using HEK293-Blue TLR-2/-4 cells and by computational docking simulations.

RESULTS

In MI patients, anti-ApoA-1 IgG positivity was associated with higher levels of IL-6, TNF-α and MMP-9, but lower MMP-3 levels. In in vitro experiments, anti-ApoA-1 antibodies bound to HDMDs in a TLR2-dependent manner, resulting in nuclear translocation of NFκB and a significant increase in TNF-α and IL-6 production. Subsequent functional studies highlighted the importance of CD14 as co-receptor in the anti-ApoA-1 IgG-TLR2-induced cytokine production. Additional bioinformatic studies identified structural homologies between TLR2 and ApoA-1, which may explain the observed cross-reactivity between antibodies against these two molecules.

CONCLUSIONS

Anti-ApoA-1 IgG positivity in MI is associated with a high-risk cytokine profile. These auto-antibodies promote inflammation by stimulating the TLR2/CD14 receptor complex, probably because of molecular mimicry, which may contribute to atherosclerosis-related complications in patients.

Autoantibodies against apolipoprotein A-1 and phosphorylcholine for diagnosis of non-ST-segment elevation myocardial infarction

OBJECTIVES

To explore the diagnostic accuracies of anti-apolipoproteinA-1 (anti-ApoA-1) IgG and anti-phosphorylcholine (anti-PC) IgM alone, expressed as a ratio (anti-ApoA-1 IgG/anti-PC IgM), and combined with the Thrombolysis In Myocardial Infarction (TIMI) score for non-ST-segment elevation myocardial infarction (NSTEMI) (NSTEMI-TIMI score) to create a new diagnostic algorithm - the Clinical Autoantibody Ratio (CABR) score - for the diagnosis of NSTEMI and subsequent cardiac troponin I (cTnI) elevation in patients with acute chest pain (ACP).

METHODS

In this single-centre prospective study, 138 patients presented at the emergency department with ACP without ST-segment elevation myocardial infarction. Anti-ApoA-1 IgG and anti-PC IgM were assessed by enzyme-linked immunosorbent assay on admission. Post hoc determination of the CABR score cut-off was performed by receiver operating characteristics analyses.

RESULTS

The adjudicated final diagnosis was NSTEMI in 17% (24/138) of patients. Both autoantibodies alone were found to be significant predictors of NSTEMI diagnosis, but the CABR score had the best diagnostic accuracy [area under the curve (AUC): 0.88; 95% confidence interval (CI): 0.82-0.95]. At the optimal cut-off of 3.3, the CABR score negative predictive value (NPV) was 97% (95% CI: 90-99). Logistic regression analysis showed that a CABR score >3.3 increased the risk of subsequent NSTEMI diagnosis 19-fold (odds ratio: 18.7; 95% CI: 5.2-67.3). For subsequent cTnI positivity, only anti-ApoA-1 IgG and CABR score displayed adequate predictive accuracies with AUCs of 0.80 (95% CI: 0.68-0.91) and 0.82 (95% CI: 0.70-0.94), respectively; the NPVs were 95% (95% CI: 90-98) and 99% (95% CI: 94-100), respectively.

CONCLUSION

The CABR score, derived from adding the anti-ApoA-1 IgG/anti-PC IgM ratio to the NSTEMI-TIMI score, could be a useful measure to rule out NSTEMI in patients presenting with ACP at the emergency department without electrocardiographic changes.

Anti-apoA-1 IgG and oxidized LDL are raised in rheumatoid arthritis (RA): potential associations with cardiovascular disease and RA disease activity

OBJECTIVE

To determine whether emerging cardiovascular risk factors such as anti-apolipoprotein A-1 (anti-apoA-1) immunoglobulin (Ig)G and oxidized low density lipoprotein (oxLDL) are associated with cardiovascular disease (CVD), carotid intima-media thickness (IMT), and disease activity in rheumatoid arthritis (RA).

METHOD

We determined the aforementioned associations in 69 RA patients with disease duration of 5 years and 46 controls matched by age, sex, and smoking status. Anti-apoA-1 IgG and oxLDL were measured by enzyme-linked immunosorbent assay (ELISA). Carotid arteries were examined by ultrasound. Disease Activity Score calculated on 28 joints (DAS28) was used to assess disease activity.

RESULTS

CVD prevalence was higher among RA patients than controls (17% vs. 2%, p = 0.01) but there was no difference in IMT (median: 0.67 vs. 0.66, p = 0.33). RA patients had a higher anti-apoA-1 IgG prevalence than controls (20% vs. 0%, p = 0.001). Anti-apoA-1 IgG and oxLDL levels were higher in cases than controls [median: 0.33 vs. 0.175 optical density (OD), p = 0.03; and 121 vs. 37.2 U/L, p = 0.0001, respectively]. Anti-apoA-1 IgG-positive patients had higher levels of oxLDL (median: 140.5 vs. 112 U/L, p = 0.01) than those tested negative. Receiver operating characteristic (ROC) curve analysis showed that only anti-apoA-1 IgG was a modest but significant predictor of CVD [area under the curve (AUC) = 0.65, p = 0.03] in RA patients. oxLDL was significantly associated with RA disease activity, whereas anti-apoA-1 IgG was not.

CONCLUSIONS

Anti-apoA-1 IgG could be a marker of CVD in RA, whereas oxLDL levels seem to reflect RA disease activity. Other causes of CVD than a general increase in atherosclerosis (as determined by IMT measurements) including plaque stability may therefore be of importance to explain the increased incidence of CVD in RA.

Cardiac biomarkers for risk stratification in non-massive pulmonary embolism: a multicenter prospective study

BACKGROUND

Troponins (cTnI and cTnT), N-terminal pro-Brain Natriuretic Peptide (NT-proBNP), myoglobin, heart-type fatty acid-binding protein (H-FABP) and fibrin D-Dimer are emergent candidates for risk stratification in pulmonary embolism (PE).

OBJECTIVE

To compare the respective prognostic values of biomarker with non-massive PE to predict an adverse outcome at 3 months.

PATIENTS/METHODS

One hundred and forty-six consecutive patients with non-massive PE were included in this multicenter prospective study. The combined outcome consisted of intensive care monitoring on admission, death or hospitalization attributable to either a PE-related complication [defined by PE/deep vein thrombosis (DVT) relapse or major bleeding under anticoagulation] or to dyspnoea with or without chest pain during follow-up.

RESULTS

The outcome was met in 12% of patients. In univariate analysis, a NT-proBNP level above 300 pg/ml was the strongest predictor of unfavorable outcome with an odds ratio (OR) of 15.8 [95% confidence interval (CI): 2.05-122). ORs for the other variables were: 8.0 for D-dimer >2000 ng/ml (95% CI: 1.1-64), 4.7 for H-FABP >6 ng/ml (95% CI:1.5-14.8), 3.5 for cTnI >0.09 ng/ml (95% CI:1.2-9.7), 3.4 for myoglobin >70 ng/ml (95% CI:0.9-12.2). Receiver operating curve (ROC) analysis indicated that NT-proBNP was the best predictor [area under the curve (AUC) 0.84; 95%CI: 0.76-0.92; P < 0.0001] with a negative predictive value of 100% (95% CI: 91-100) at 300 pg/ml. At that cut-off, the true negative rate for NT-proBNP was 40%. In multivariate analysis, NT-proBNP was the only significant independent predictors.

CONCLUSIONS

NT-proBNP appears to be a good risk stratification marker in identifying low-risk patients with non-massive PE who could be treated in an outpatient setting.

[Acute chest syndrome in sickle cell disease and acute respiratory distress syndrome--from pathophysiology to therapy]

Acute chest syndrome is frequent in the homozygous sickle cell disease population. It can evolve to an acute respiratory distress syndrome. Pulmonary artery hypertension or chronic lung sequellae are common. The vasoocclusive phenomenon is due to capillary blockade, followed by an activation of inflammation, and adhesion phenomena further increasing the damage. Decreased blood oxygenation leads to an aggravation of the sickle crisis. Nitric oxide disregulation has been recently highlighted. Diagnosis must be suspected in patients presenting with sickle crisis, fever, low blood oxygenation and lung infiltrates. Early antibiotherapy, adequate oxygenation, blood transfusion and erythrocytapheresis are key points for management. Preventive measures such as iterative transfusion-chelation, hydroxyurea or repetitive erythrocytapheresis are all useful.