Introduction: The purpose of this study was theevaluation of synovial effusion (SE), synovial fluid (SF) and synovial tissue (ST) biomarkers in relation to disease activity indexes to assess the response to intraarticular (IA) tumor necrosis factor (TNF)-α blockers in psoriatic arthritis (PsA). Methods: Systemic and local disease activity indexes (disease activity score (DAS); the Ritchie articular index (mRAI), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP); Thompson articular (THOMP) and joint articular (KJAI)-Index ) and ST samples were assessed at baseline, throughout treatment, and during the follow-up in 14 patients affected with PsA who underwent IA injections (0.5 ml to 12.5 mg) in the knee joint of etanercept (E) or placebo (P) once every two weeks for a 10-week period. Total SF white blood cell (WBC) counts (WBC/μl) and SF cytokine/chemokine (CK/CCK) levels were measured before IA-E at baseline, after IA-E, and as long as there were adequate amounts of SF for knee aspiration (post). Characterization of synovial mononuclear cell infiltration and synovial vessels was carried out in 8 out of 14 knees by staining serial sections of synovial tissue biopsies for CD45, CD3, CD68, CD31 and CD105. Results: At baseline, CRP and/or ESR were significantly correlated with SF-CK (interleukin- (IL-)1β, IL-1Ra, IL-6, IL-8) and CCK (CCL3). Post-IA injections, there was a decrease in SE in the knees in which aspiration following IA-E injection was possible as well as a significant reduction in SF WBC/μl and in SF-CK (IL-1β, IL-1Ra, IL-6 and IL-22). Pre- and post-IA-E injections, there were significant correlations between ST markers and SF-CK (IL-1β with CD45; IL-1β and IL-6 with CD31) and between SF-CCK (CCL4 and CCL3 with CD3). At the end of the study, there was a significant reduction in disease activity indexes (CRP, DAS, RAI, THOMP, KJAI) as well as in the ST markers (CD45; CD3). Conclusions: Synovial effusion regression is a reliable indicator of the response to IA TNF-α blockers in PsA patients as it is confirmed by the correlation between SF biomarkers to disease activity and synovial tissue inflammation.

ApoA-1 (apolipoprotein A-1) is the main component of HDL (high-density lipoprotein) and stabilizes PON-1 (paraoxonase-1), which prevents lipid peroxidation and oxLDL (oxidized low-density lipoprotein) formation. Autoantibodies against apoA-1 [anti-(apoA-1) IgG] have been found in antiphospholipid syndrome and systemic lupus erythematosous, two diseases with an increased risk of thrombotic events, as well as in ACS (acute coronary syndrome). OxLDL levels are also elevated in these diseases. Whether anti-(apoA-1) IgGs exist in other prothrombotic conditions, such as APE (acute pulmonary embolism) and stroke, has not been studied and their potential association with oxLDL and PON-1 activity is not known. In the present study, we determined prospectively the prevalence of anti-(apoA-1) IgG in patients with ACS (n=127), APE (n=58) and stroke (n=34), and, when present, we tested their association with oxLDL levels. The prevalance of anti-(apoA-1) IgG was 11% in the ACS group, 2% in the control group and 0% in the APE and stroke groups. The ACS group had significantly higher median anti-(apoA-1) IgG titres than the other groups of patients. Patients with ACS positive for anti-(apoA-1) IgG had significantly higher median oxLDL values than those who tested negative (226.5 compared with 47.7 units/l; P<0.00001) and controls. The Spearman ranked test revealed a significant correlation between anti-(apoA-1) IgG titres and serum oxLDL levels (r=0.28, P<0.05). No association was found between PON-1 activity and oxLDL or anti-(apoA-1) IgG levels. In conclusion, anti-(apoA-1) IgG levels are positive in ACS, but not in stroke or APE. In ACS, their presence is associated with higher levels of oxLDL and is directly proportional to the serum concentration of oxLDL. These results emphasize the role of humoral autoimmunity as a mediator of inflammation and coronary atherogenesis.

Background: Comparative data of SARS-CoV-2 IgM/IgG serology rapid diagnostic tests (RDTs) is scarce. We thus performed a head-to-head comparison of three RDTs. Methods: In this unmatched case-control study, blood samples from 41 RT-PCR-confirmed COVID-19 cases and 50 negative controls were studied. The diagnostic accuracy of three commercially available COVID-19 RDTs: NTBIO (RDT-A), Orient-Gene (RDT-B), and MEDsan (RDT-C), against both a recombinant spike-expressing immunofluorescence assay (rIFA) and Euroimmun IgG ELISA, was assessed. RDT results concordant with the reference methods, and between whole blood and plasma, were established by the Kendall coefficient. Results: COVID-19 cases’ median time from RT-PCR to serology was 22 days (interquartile range (IQR) 13–31 days). Whole-blood IgG detection with RDT-A, -B, and -C showed 0.93, 0.83, and 0.98 concordance with rIFA. Against rIFA, RDT-A sensitivity (SN) was 92% (95% CI: 78–98) and specificity (SP) 100% (95% CI: 91–100), RDT-B showed 87% SN (95% CI: 72–95) and 98% SP (95% CI: 88–100), and RDT-C 100% SN (95% CI: 88–100) and 98% SP (95% CI: 88–100). Against ELISA, SN and SP were above 90% for all three RDTs. Conclusions: RDT-A and RDT-C displayed IgG detection SN and SP above 90% in whole blood. These RDTs could be considered in the absence of routine diagnostic serology facilities.

Keller P‐F, Pagano S, Roux‐Lombard P, Sigaud P, Rutschmann OT, Mach F, Hochstrasser D Vuilleumier N (Geneva University Hospitals, Geneva). Autoantibodies against apolipoprotein A‐1 and phosphorylcholine for diagnosis of non‐ST‐segment elevation myocardial infarction. J Intern Med 2012; 271: 451–462. 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.