Anakinra for Refractory Pseudogout in Patients with End-stage Renal Disease on Haemodialysis.

Calcium pyrophosphate deposition (CPPD) arthritis is the second most common type of crystal-induced arthritis after gout. Acute flares are commonly treated with non-steroidal anti-inflammatory drugs, intra-articular or short-term systemic glucocorticoids or colchicine. However, since there is no pharmacological treatment to reduce CPPD crystal burden, relapsing or chronic CPPD arthritis may be challenging to treat, particularly in patients with end-stage renal disease who are at risk for toxicity of the above medications. Since IL-1ß appears to be driving CPPD arthritis, we treated two patients with chronic CPPD arthritis and end-stage renal disease on haemodialysis with the IL-1ß receptor antagonist anakinra. In both patients, arthritis resolved quickly, while continuation of anakinra maintained remission and allowed complete glucocorticoid withdrawal. Therefore, anakinra may be a safe and effective option both for short and long-term treatment of CPPD arthritis in patients on chronic renal replacement therapy.

Identification and characteristics of patients with potential difficult-to-treat Psoriatic Arthritis: exploratory analyses of the Greek PsA registry.

OBJECTIVE: To present the characteristics of patients with potential difficult-to-treat (D2T) psoriatic arthritis (PsA). METHODS: We used data from the Greek multicentre registry of PsA patients. D2T-PsA was defined as follows: patients with at least 6-months disease duration, who have failed to at least 1 csDMARD and at least 2 bDMARDs/tsDMARDs with a different mechanism of action and have either at least moderate disease activity (MODA) defined as DAPSA > 14, and/or are not at minimal disease activity (MDA). Demographic and clinical characteristics were compared between D2T and non-D2T PsA patients. In two sensitivity analyses, patients classified as D2T solely according to the MODA or MDA criterion were examined separately. RESULTS: Among 467 patients included, 77 (16.5%) were considered D2T and 390 non-D2T PsA. Compared with non-D2T, patients with D2T PsA presented more commonly with extensive psoriasis (p< 0.0001) and were more likely to have higher BMI (p= 0.023) and a history of inflammatory bowel disease (p= 0.026). In the MODA and MDA sensitivity analyses, 7.5% and 12.5% of patients were considered D2T, respectively. In both sensitivity analyses, extensive psoriasis was again identified as an independent variable for D2T PsA (p= 0.001 and p= 0.008, respectively). Moreover, female gender (p= 0.034) in the MODA analysis and axial disease (p= 0.040) in the MDA analysis were independent variables for D2T PsA. CONCLUSION: Despite the availability of therapies, D2T PsA is common in real-life cohorts of patients with PsA and extensive psoriasis. High BMI, female gender, axial-disease, and history of IBD were also associated with D2T PsA.

Glucocorticoid discontinuation rate and risk factors for relapses in a contemporary cohort of patients with giant cell arteritis.

The rates of relapses and therapy discontinuation in patients with giant cell arteritis (GCA) in the modern therapeutic era have not been defined. We aimed to evaluate the glucocorticoid (GC) discontinuation rate and the factors associated with relapses in a contemporary GCA cohort. Patient and treatment data were collected cross-sectionally at first evaluation and 2 years later (second evaluation), in a multicenter, prospective GCA cohort. Predictors of relapses were identified by logistic regression analyses. 243 patients with GCA were initially included (67% women, mean age at diagnosis: 72.1 years, median disease duration: 2 years) while 2 years later complete data for 160 patients were available and analyzed. All patients had received GCs at diagnosis (mean daily prednisolone dose: 40 mg) while during follow-up, 37% received non-biologic and 16% biologic agents, respectively. At second evaluation, 72% of patients were still on therapy (GCs: 58% and/or GC-sparing agents: 29%). Relapses occurred in 27% of patients during follow-up; by multivariable logistic regression analysis, large vessel involvement at diagnosis [odds ratio (OR) = 4.22], a cardiovascular event during follow-up (OR = 4.60) and a higher initial GC daily dose (OR = 1.04), were associated with these relapses. In this large, real-life, contemporary GCA cohort, the rates of GC discontinuation and relapses were 40% and 27%, respectively. Large vessel involvement, a higher GC dose at diagnosis and new cardiovascular events during follow-up were associated with relapses.

Investigating the role of "Immature Myeloid Cells" as Drivers of Inflammation and Disease Persistence in Psoriatic Arthritis.

Background: Despite the development of treatments targeting T cell co-stimulation and cytokines TNF, IL-12/23, and IL-17, less than half of patients within clinical trials achieve high levels of clinical response. This fact, as well as the absence of prognostic biomarkers represents major unmet clinical needs that necessitate further investigation of the disease pathophysiology. Myeloid cells are critical components of PsA inflammatory mechanisms, being a highly prevalent immune population in biopsies of PsA target tissues, such as the skin and the synovium. Through their antigen-presenting capacity and their pro-angiogenic and pro-inflammatory properties myeloid cells could contribute to persistent inflammation in PsA leading to treatment-resistant disease. To this end, we have recently shown the expansion of monocytes in the blood of PsA patients compared to healthy subjects. Importantly, we have also identified an immature myeloid cell population in patients with highly active, refractory disease, indicating the presence of an "emergency myelopoiesis" process in PsA. Aim of the study: In this research protocol, we aim to decipher the pro-inflammatory "myeloid signature" in patients with active PsA and explore the role of immature myeloid cells in disease pathophysiology and their potential as prognostic biomarkers. Methods: To address this, we will isolate and analyse monocytes and immature myeloid cells from PsA patients -before and after a 6-month treatment course- focusing on differences between responders and non-responders. In this context, we will perform a thorough phenotypic and functional analysis of these cells, identify their expression signature in an already established whole blood RNA-seq dataset and investigate their presence in target tissues, such as the skin and synovial fluid. Anticipated benefits: This study will elucidate the role of myeloid cells in disease propagation by further defining the involvement of immature myeloid cells in PsA.

JAK Inhibitors for the Treatment of Axial Spondyloarthritis.

Axial spondyloarthritis (axSpA) is a chronic disease characterized by inflammation and new bone formation that causes pain and results in functional impairment and long-term disability. Biologic agents targeting TNFα or IL-17 have been the mainstay of treatment for patients with axSpA and an inadequate response to nonsteroidal anti-inflammatory drugs. However, a proportion of axSpA patients do not respond adequately to those drugs either, creating the need to target alternative disease pathways. Janus kinase (JAK) inhibitors (JAKis) are a group of targeted synthetic disease-modifying anti-rheumatic drugs that block the intracellular signalling pathway of several proinflammatory cytokines. Given their efficacy in the management of rheumatoid arthritis and that JAKs mediate the signalling of cytokines involved in the pathogenesis of axSpA as well, JAKis have been successfully tested in a number of clinical trials in axSpA, which has led to the approval of two compounds, tofacitinib and upadacitinib for the treatment of the disease. Data from new clinical trials, long-term extensions of completed trials, and real-life observational studies that continuously emerge will shape the efficacy and safety profile and ultimately the place of JAKis in the treatment of AxSpA.

Omicron variant dominance and anti-SARS-CoV-2 vaccination are key determinants for a milder course of COVID-19 in patients with systemic autoimmune rheumatic diseases.

INTRODUCTION: This study aimed to determine whether the introduction of anti-SARS-CoV-2 vaccines and the dominance of the omicron variant had a significant impact on the outcome of COVID-19 in patients with systemic autoimmune rheumatic diseases (SAIRDs). METHODS: Using data entered to the Greek Rheumatology Society COVID-19 registry, we investigated the incidence of hospitalization and death due to COVID-19, during the successive periods of the pandemic according to the prevalent strain (wild-type, Alpha, Delta, Omicron) in vaccinated and unvaccinated patients. Variables independently associated with hospitalization and death were explored using multivariate regression analyses, while Kaplan-Meier curves were used to depict survival data. RESULTS: From August 2020 until June 30, 2022, 456 cases (70.2% females) of COVID-19 with a mean age (± SD) of 51.4 ± 14.0 years were reported. In unvaccinated patients, the proportions of hospitalization and death were 24.5% and 4%, compared to 12.5% and 0.8% in the vaccinated group (p < 0.001 for both comparisons). The rates of hospitalization for the wild-type, Alpha, Delta, and Omicron periods were 24.7%, 31.3%, 25.9%, and 8.1% respectively (p < 0.0001), while the case fatality rates were 2.7%, 4%, 7%, and 0%, respectively (p = 0.001). Using multivariable regression analysis, factors independently associated with hospitalization were infection by a non-Omicron variant, being non-vaccinated, exposure to rituximab, older age, and respiratory and cardiovascular disease. Independent predictors for death were contracting COVID-19 during the Alpha or Delta period, pulmonary disease, and older age, while being vaccinated was protective. CONCLUSIONS: In this 2-year analysis, the rates of hospitalization and death among patients with SAIRDs have declined significantly. Vaccination and the dominance of the Omicron variant appear to be the major determinants for this shift. Key points • During the late phase of the pandemic, the proportion of severe COVID-19 cases, defined as requiring hospitalization or resulting in death, in patients with systemic autoimmune rheumatic diseases has declined. • Anti-SARS-CoV-2 vaccination and the dominance of the Omicron strain are the key factors that have independently contributed to this shift.

Apremilast for biologic-naïve, peripheral psoriatic arthritis, including patients with early disease: results from the APROACH observational prospective study.

To evaluate the effect of the phosphodiesterase 4 inhibitor apremilast in biologic-naïve patients with early peripheral PsA in terms of disease activity, clinical manifestations, patient-perceived outcomes, as well as apremilast's safety profile in routine care settings of Greece. Non-interventional, multicenter, 52-week prospective cohort study, enrolling biologic-naïve patients with early active peripheral PsA who started apremilast after intolerance or inadequate response (within the first 12 months of treatment) to an initial conventional synthetic (cs)DMARD treatment. Non-responder imputation was applied for missing data.In total, 167 consecutive patients (mean age: 52.5 years; median PsA duration: 0.9 years) were analyzed. At baseline, the median (interquartile range) clinical Disease Activity in Psoriatic Arthritis (cDAPSA) score was 22.0 (16.0-29.0), with 86.8% of patients having at least moderate (29.3% high) disease activity; 87.4% had skin psoriasis, 37.7% nail psoriasis, 30.7% enthesitis, and 12.4% dactylitis. At 16, 24, and 52 weeks, 28.7, 42.5, and 48.5% of patients, achieved ≥ 50% improvement in their baseline cDAPSA score, respectively. At week 52, 55.6, 50, and 26.8% of evaluable patients achieved complete resolution of enthesitis, dactylitis and nail psoriasis, respectively. Improvements were also observed in patient's health state assessed by the Psoriatic Arthritis Impact of Disease 12-item questionnaire, and health-related quality of life. The 52-week drug survival rate was 75%, while 13.8% of patients experienced at least one adverse drug reaction.Biologic-naïve patients with early PsA, treated with apremilast experienced significant improvements in disease activity, extra-articular manifestations and patient-centered outcomes, accompanied by a favorable tolerability profile.

Obstetric outcomes in women with rheumatic disease and COVID-19 in the context of vaccination status.

OBJECTIVE: To describe obstetric outcomes based on COVID-19 vaccination status, in women with rheumatic and musculoskeletal diseases (RMDs) who developed COVID-19 during pregnancy. METHODS: Data regarding pregnant women entered into the COVID-19 Global Rheumatology Alliance registry from 24 March 2020-25 February 2022 were analysed. Obstetric outcomes were stratified by number of COVID-19 vaccine doses received prior to COVID-19 infection in pregnancy. Descriptive differences between groups were tested using the chi-squared or Fisher's exact test. RESULTS: There were 73 pregnancies in 73 women with RMD and COVID-19. Overall, 24.7% (18) of pregnancies were ongoing, while of the 55 completed pregnancies, 90.9% (50) of pregnancies resulted in livebirths. At the time of COVID-19 diagnosis, 60.3% (n = 44) of women were unvaccinated, 4.1% (n = 3) had received one vaccine dose while 35.6% (n = 26) had two or more doses. Although 83.6% (n = 61) of women required no treatment for COVID-19, 20.5% (n = 15) required hospital admission. COVID-19 resulted in delivery in 6.8% (n = 3) of unvaccinated women and 3.8% (n = 1) of fully vaccinated women. There was a greater number of preterm births (PTB) in unvaccinated women compared with fully vaccinated 29.5% (n = 13) vs 18.2% (n = 2). CONCLUSIONS: In this descriptive study, unvaccinated pregnant women with RMD and COVID-19 had a greater number of PTB compared with those fully vaccinated against COVID-19. Additionally, the need for COVID-19 pharmacological treatment was uncommon in pregnant women with RMD regardless of vaccination status. These results support active promotion of COVID-19 vaccination in women with RMD who are pregnant or planning a pregnancy.

Disease Profile and Achievement of Therapeutic Goals in a Modern, Nationwide Cohort of 923 Patients with Psoriatic Arthritis.

Background: Psoriatic arthritis (PsA) is a heterogenous chronic inflammatory disease affecting skin, joints, entheses, and spine with various extra-musculoskeletal manifestations and comorbidities. The reported patient, disease and treatment characteristics in the modern therapeutic era are limited. Methods: In this cross-sectional, multi-centre, nationwide study, we recorded the demographic, clinical, and therapeutic characteristics as well as the comorbidities of patients with PsA seen for 1 year (1/1/2022-31/12/2022). Results: 923 patients (55% females) with a median (IQR) age of 57 (48-65) years and a mean disease duration of 9.5 years were enrolled. Family history of psoriasis and PsA was noted in 28.3% and 6.3%, respectively. Most patients had limited psoriasis (BSA<3: 83%) while enthesitis, dactylitis, nail and axial involvement reported in 48.3%, 33.2%, 43% and 25.9% of patients, respectively. Regarding comorbidities, approximately half of patients had dyslipidaemia (42%) or hypertension (45.4%), 36.8% were obese and 17% had diabetes while 22.7% had a depressive disorder. Overall, 60.1% received biologics and among them more patients treated with anti-IL-17 or -12/23 agents were on monotherapy (64.2%) compared to those on TNFi monotherapy (49.4%, p=0.0001). The median PsA activity as assessed by the DAPSA score was 6 (IQR: 2.3 - 13.1) with 46% of patients reaching minimal disease activity status (MDA). Conclusion: In this large, real life, modern cohort of patients with PsA with frequent comorbidities who were treated mainly with biologics, almost half achieved minimal disease activity. These results show the value of existing therapeutic approaches while at the same time highlight the existing unmet needs.

Inflammatory Bowel Disease-related Spondyloarthritis: The Last Unexplored Territory of Rheumatology.

The Spondyloarthritides (SpA) are a group of chronic inflammatory d iseases a ffecting th e spine, peripheral joints and entheses, as well as extra-skeletal structures, including the gastrointestinal tract. On the other hand, inflammatory b owel d isease (IBD), e ither Crohn's d isease o r ulcerative colitis, often affects extra-intestinal sites, including the axial and/or peripheral skeleton. IBD-related arthritis is the type of SpA that occurs in patients affected by IBD, with an incidence up to 50% during the IBD course. Although both manifestations are apparently the result of a common pathogenetic process, physicians often fail to recognize the disease in its entirety: thus, IBD-SpA is managed as two separate diseases, a musculoskeletal and a gastrointestinal one, with a profound impact on patient quality of life. Moreover, the specialty of the treating physician determines the clinical and laboratory tools for disease assessment, which, in turn, guide treatment decisions that may overlook either affected system or even act in the opposite direction. Raising awareness of the intestinal and musculoskeletal manifestations among rheumatologists and gastroenterologists will lead to earlier diagnosis and a multidisciplinary approach, particularly regarding pharmacologic treatments. Given the lack of trial evidence on immunomodulatory drugs in IBD-SpA it is imperative for researchers in both medical disciplines to join efforts, in order to determine referral strategies, appropriate composite measures for disease assessment, treatment algorithms and therapeutic targets.

Real-Life Outcome of Lupus Nephritis with Current Therapies: Study Protocol of a Multicentre Observational Study.

Lupus nephritis (LN) affects a significant proportion of patients with systemic lupus erythematosus (SLE) and is characterised by increased morbidity and mortality. The updated joint EULAR/European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) recommendations for the management of LN have set as target of therapy the optimisation (preservation or improvement) of kidney function, accompanied by a reduction in proteinuria of at least 25% by 3 months, 50% by 6 months, and below 500-700 mg/g by 12 months (complete clinical response). It is currently unknown what proportion of Greek patients with LN reach these proposed targets with the current available treatments. At the same time, recent successful phase 3 trials have led to the approval of both belimumab and voclosporin for the treatment of patients with LN and have steered discussions as to whether the "induction-maintenance" paradigm should be substituted by an early combination treatment for all patients. To inform future therapeutic decisions and facilitate the positioning of these new drugs in the therapeutic algorithm of LN, the current study protocol aims to map the unmet needs in the treatment of LN in Greece, by quantifying the proportion of patients who attain the recommended treatment targets in everyday clinical practice.

Serum granulocyte-macrophage colony-stimulating factor (GM-CSF) is increased in patients with active radiographic axial spondyloarthritis and persists despite anti-TNF treatment.

BACKGROUND: Accumulating evidence supports the role of monocytes and neutrophils in radiographic axSpA (r-axSpA). Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a growth factor for both leukocyte lineages and a pro-inflammatory cytokine activating myeloid cells and promoting osteoclastogenesis. It acts through the JAK-STAT pathway. We measured serum GM-CSF and markers of bone metabolism in patients with r-axSpA before and after anti-TNF treatment. METHODS: Patients with active r-axSpA despite treatment with NSAIDs, all eligible for treatment with a biologic agent, were recruited. Healthy donors were sampled as controls. Serum was collected before (baseline) and after 4-6 months (follow-up) of anti-TNF treatment and the following molecules were measured with ELISA: GM-CSF, sclerostin (SOST), and dickkopf-1 (Dkk-1). RESULTS: Twelve r-axSpA patients (7 males, 5 females, median age 37 years) with a median disease duration of 1 year and 16 age- and sex-matched controls were included. At baseline, patients had mean BASDAI 6.3±2 and ASDAS 3.2±0.7, which decreased to 4.1±1.7 and 2.2±0.6 at follow-up, respectively. At baseline, r-axSpA patients had significantly higher mean serum levels of GM-CSF (150 vs 62pg/ml, p=0.049), significantly lower Dkk-1 (1228 vs 3052pg/ml, p=0.001), but similar levels of SOST (369 vs 544pg/ml, p=0.144) compared to controls. Anti-TNF treatment did not affect GM-CSF, Dkk-1, or SOST levels. Spearman correlation analysis showed that GM-CSF correlated positively with ASDAS at baseline (r=0.61, p=0.039), while no correlations were identified between bone markers (Dkk-1, SOST) on one hand and GM-CSF or disease activity indices on the other. CONCLUSIONS: GM-CSF is increased in patients with active AS and strongly correlates with disease activity. TNF inhibition does not affect GM-SCF levels, despite improving disease activity. GM-CSF may represent an important pathway responsible for residual inflammation during TNF blockade, but also a potential target of JAK inhibitors, explaining their efficacy in r-axSpA.

Complement C3 inhibition in severe COVID-19 using compstatin AMY-101.

Complement C3 activation contributes to COVID-19 pathology, and C3 targeting has emerged as a promising therapeutic strategy. We provide interim data from ITHACA, the first randomized trial evaluating a C3 inhibitor, AMY-101, in severe COVID-19 (PaO2/FiO2 ≤ 300 mmHg). Patients received AMY-101 (n = 16) or placebo (n = 15) in addition to standard of care. AMY-101 was safe and well tolerated. Compared to placebo (8 of 15, 53.3%), a higher, albeit nonsignificant, proportion of AMY-101-treated patients (13 of 16, 81.3%) were free of supplemental oxygen at day 14. Three nonresponders and two placebo-treated patients succumbed to disease-related complications. AMY-101 significantly reduced CRP and ferritin and restrained thrombin and NET generation. Complete and sustained C3 inhibition was observed in all responders. Residual C3 activity in the three nonresponders suggested the presence of a convertase-independent C3 activation pathway overriding the drug's inhibitory activity. These findings support the design of larger trials exploring the potential of C3-based inhibition in COVID-19 or other complement-mediated diseases.

Combined administration of inhaled DNase, baricitinib and tocilizumab as rescue treatment in COVID-19 patients with severe respiratory failure.

Aiming to reduce mortality in COVID-19 with severe respiratory failure we administered a combined rescue treatment (COMBI) on top of standard-of-care (SOC: dexamethasone/heparin) consisted of inhaled DNase to dissolve thrombogenic neutrophil extracellular traps, plus agents against cytokine-mediated hyperinflammation, namely anti-IL-6-receptor tocilizumab and JAK1/2 inhibitor baricitinib. Patients with PaO2/FiO2 < 100 mmHg were analysed. COMBI group (n = 22) was compared with similar groups that had received SOC alone (n = 26) or SOC plus monotherapy with either IL-1-receptor antagonist anakinra (n = 19) or tocilizumab (n = 11). COMBI was significantly associated with lower in-hospital mortality and intubation rate, shorter duration of hospitalization, and prolonged overall survival after a median follow-up of 110 days. In vitro, COVID-19 plasma induced tissue factor/thrombin pathway in primary lung fibroblasts. This effect was inhibited by the immunomodulatory agents of COMBI providing a mechanistic explanation for the clinical observations. These results support the conduct of randomized trials using combined immunomodulation in COVID-19 to target multiple interconnected pathways of immunothrombosis.

Remission or low disease activity at pregnancy onset are linked to improved foetal outcomes in women with systemic lupus erythematosus: results from a prospective observational study.

OBJECTIVES: Systemic lupus erythematosus (SLE) patients show variably increased risk for pregnancy complications. We analysed pregnancy outcomes (foetal and maternal), patterns of disease activity and use of medications in a contemporary Caucasian SLE population. METHODS: Prospective observational study, involving hospital units and private rheumatologists in Greece, of incident pregnancies (period 2015-2018) in women with SLE. Clinical and obstetrical monitoring was performed at regular intervals up to 9 months post-partum. Regression and mixed model analyses were used to determine predictors for adverse foetal outcomes and flares. RESULTS: We monitored 82 pregnancies in 64 SLE patients. Foetal loss, prematurity and small for gestational age neonate occurred at 15.8%, 34.1% and 8.5%, respectively; 53.7% of pregnancies were complicated with at least one adverse outcome. Patients with antiphospholipid antibodies (aPL) had increased risk (odds ratio [OR] 5.67, p=0.015), whereas those at low disease activity at pregnancy onset were protected (OR 0.20, p=0.024) against foetal complications. Persistent activity and glucocorticoid intake during pregnancy also predicted poor foetal outcomes. SLE patients experienced an average 1.08 mild/moderate and 0.27 severe flares. The latter occurred more frequently post-partum, in patients with alopecia (OR 8.92, p=0.003), hypocomplementaemia (OR 10.34, p=0.038) and nephritis (OR 7.32, p=0.052). Lupusactivity post-labour was paralleled by decreased use of hydroxychloroquine, glucocorticoids and azathioprine. CONCLUSIONS: In SLE women, foetal complications are common especially in the presence of aPL and increased activity, which corroborates the importance of pregnancy planning and tight disease control at pregnancy onset. Flares, mostly mild or moderate, can occur both during and after pregnancy.

Better outcomes of COVID-19 in vaccinated compared to unvaccinated patients with systemic rheumatic diseases.

OBJECTIVE: Τo report outcomes of breakthrough COVID-19 in comparison with COVID-19 in unvaccinated patients with systemic rheumatic diseases (SRDs). METHODS: Patients with SRD with COVID-19 (vaccinated and unvaccinated) were included by their rheumatologists in a registry operated by the Greek Rheumatology Society in a voluntarily basis. Type, date and doses of SARS-CoV-2 vaccines were recorded, and demographics, type of SRD, concurrent treatment, comorbidities and COVID-19 outcomes (hospitalisation, need for oxygen supplementation and death) were compared between vaccinated and unvaccinated patients. RESULTS: Between 1 March 2020 and 31 August 2021, 195 patients with SRD with COVID-19 were included; 147 unvaccinated and 48 vaccinated with at least one dose of a SARS-CoV-2 vaccine (Pfizer n=38 or AstraZeneca n=10). Among vaccinated patients, 29 developed breakthrough COVID-19 >14 days after the second vaccine dose (fully vaccinated), while 19 between the first and <14 days after the second vaccine dose (partially vaccinated). Despite no differences in demographics, SRD type, treatment or comorbidities between unvaccinated and vaccinated patients, hospitalisation and mortality rates were higher in unvaccinated (29.3% and 4.1%, respectively) compared with partially vaccinated (21% and 0%) or fully vaccinated (10.3% and 0%) patients. CONCLUSIONS: Vaccinated patients with SRD with breakthrough COVID-19 have better outcomes compared with unvaccinated counterparts with similar disease/treatment characteristics.

Prevalence of anti-SARS-CoV-2 IgG antibodies in a group of patients, a control group, and healthcare workers of Thrace area in Greece, by the use of two distinct methods.

INTRODUCTION: The aim of this study was to assess the clinical performance of different automated immunoassays available in Europe to detect anti-SARS-CoV-2 antibodies; an ELISA assay and a CLIA. The second goal was to estimate the seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Evros area during the first pandemic wave of COVID-19. METHODS: The study included serum samples from 101 patients with confirmed COVID-19 by RT-PCR and 208 negative patients. Furthermore, it included 1036 healthcare workers (HWs) of the Evros Region, Northern Greece. The measurement of anti-SARS-CoV-2 antibodies was performed using the Abbott SARS-CoV-2 IgG and anti-SARS-CoV-2 ELISA IgG assay (Epitope Diagnostics, USA). RESULTS: Of 101 confirmed COVID-19 patients, 82 were hospitalized and 19 were outpatients. Hospitalized patients had higher IgG levels in comparison to outpatients (6.46±2.2 vs. 3.52±1.52, p<0.001). Of 208 non-COVID-19 patients only 1 was positive in both ELISA and CLIA assay. SARS-CoV-2-IgG antibodies were detected in 6 HWs out of 1036 (0.58%) with mean S/CO-value of anti-SARS-CoV-2 IgG 3.12±1.3 (confidence interval 0.95), which was lower than in COVID-19 patients (3.12 vs. 5.9; p=0.016). The clinical evaluation of two immunoassays showed remarkably high true positivity rates in the confirmed COVID-19 patients. Sensitivities obtained with CLIA and ELISA methods were 99.02% vs. 97.09% and specificities 99.52% vs 99.05% respectively. CONCLUSIONS: We found an acceptable accordance between CLIA and ELISA assays in the confirmed COVID-19 patients. In all subjects included in this study in the past medical history, the information that was obtained included details about the presence of autoimmune diseases.