Amelia Rigon

Adipokines and Systemic Lupus Erythematosus : Relationship with Metabolic Syndrome and Cardiovascular Disease Risk Factors

Objective. To study concentrations of adipokines in patients with systemic lupus erythematosus (SLE) and the relationship among adipokines, the metabolic syndrome (MeS), and cardiovascular disease (CVD) risk factors. Methods. We enrolled 50 SLE patients and 26 controls, all women. Leptin, resistin, visfatin, and adiponectin were measured by commercial ELISA kits. Results. MeS prevalence was increased among subjects with SLE. Leptin levels were higher in patients with SLE than controls. Among SLE patients, independent determinants of leptin were insulin levels (p < 0.0001), triglycerides (p = 0.03), body mass index (p = 0.02), corticosteroid dosage (p = 0.02), and SLE Disease Activity Index (p = 0.005). Other adipokines did not differ between SLE patients and controls. Conclusion. Leptin was increased in SLE patients and could play a role in SLE-related cardiovascular diseases.

Indirect immunofluorescence in autoimmune diseases: Assessment of digital images for diagnostic purpose

Background: The recommended method for antinuclear antibodies (ANA) detection is indirect immunofluorescence (IIF). To pursue a high image quality without artefacts and reduce interobserver variability, this study aims at evaluating the reliability of automatically acquired digital images of IIF slides for diagnostic purposes. Methods: Ninety‐six sera were screened for ANA by IIF on HEp‐2 cells. Two expert physicians looking at both the fluorescence microscope and the digital images on computer monitor performed a blind study to evaluate fluorescence intensity and staining pattern. Cohens kappa was used as an agreement evaluator between methods and experts. Results: Considering fluorescence intensity, there is a substantial agreement between microscope and monitor analysis in both physicians. Agreement between physicians was substantial at the microscope and perfect at the monitor. Considering IIF pattern, there was a substantial and moderate agreement between microscope and monitor analysis in both physicians. Kappa between physicians was substantial both at the microscope and at the monitor. Conclusions: These preliminary results suggest that digital media is a reliable tool to help physicians in detecting autoantibodies in IIF. Our data represent a first step to validate the use of digital images, thus offering an opportunity for standardizing and automatizing the detection of ANA by IIF.

Novel opportunities in automated classification of antinuclear antibodies on HEp-2 cells.

The recommended method for antinuclear antibodies (ANA) detection is IIF but it is influenced by many different factors. In order to pursue a high image quality without artefacts and to reduce inter-observer variability, this study aims to evaluate the reliability of using automatically acquired digital images for diagnostic purposes. In this paper we present SLIM-system a comprehensive system that supports the two sides of IIF tests classification. It is based on two systems: the first labels the fluorescence intensity, whereas the second recognizes the staining pattern of positive wells. We populated a dataset of 600 images obtained from sera screened for ANA by IIF on Hep-2 cells. The error rate has been evaluated according to eight-fold cross validation method; the rates reported in the following are the mean of the tests. Performance of the system in positive/negative recognition ranges from 87% up to more than 94%. Staining pattern classification accuracy of main classes ranges from 71% to 74%. The system provides high and reliable identification of negative samples and a flexibility that permits to use this application for different purposes. The analysis of its perspective performance shows the system potential in lowering the method variability, in increasing the level of standardization and in reducing the specialist workload of more than 80%. Our data represent a first step to validate the use of Computer Aided Diagnosis (CAD), thus offering an opportunity for standardizing and automatizing the detection of ANA by IIF.

Anti-lactoferrin antibodies in systemic lupus erythematosus : isotypes and clinical correlates

Lactoferrin (LF) is a multifunctional iron-binding protein present in several mucosal secretions as well as in secondary granules of polymorphonuclear leukocytes (PMN). Anti-LF antibodies, which belong to antineutrophil cytoplasmic antibodies (ANCA), have been described in several immunomediated diseases, including systemic lupus erythematosus (SLE), with conflicting results regarding either their prevalence or clinical associations. We studied the prevalence and isotype distribution of anti-LF and their association with clinical manifestations, disease activity, and other autoantibodies in 97 patients (83 women) affected by SLE. Anti-LF were detected by enzyme-linked immunosorbent assay. Disease activity was assessed using the Systemic Lupus Activity Measure (SLAM). Cutoff for antibody positivity was set at three standard deviations (SD) above the mean optical density obtained in sera from 34 healthy subjects. Positive sera were arbitrarily subdivided into low (from >3 to 5 SD), medium (from >5 to 10 SD), and high (>10 SD) positive. IgG, IgM, and IgA anti-LF were detected in 53, 18, and 14 patients, respectively. IgG1, IgG2, IgG3, and IgG4 anti-LF were demonstrated in 34, 10, 31, and 35 patients, respectively. IgG anti-LF at the medium/high level were found in 33 patients, correlated with disease activity (p=0.017), anti-dsDNA (0.04), and anticardiolipin antibodies (p=0.02) and were associated with Raynaud’s phenomenon (p=0.028), renal involvement (p=0.007), serositis (p=0.026), and history of thrombosis (p=0.006). Anti-LF of IgM, IgA, or IgG subclass isotypes showed no correlation with clinical and serological findings. Our results demonstrate that anti-LF are frequently present in patients affected by SLE. IgG anti-LF at the medium/high level are associated with some clinical manifestations and other autoantibodies. However, it remains to be established whether anti-LF play a specific pathogenic role.

Automatic Acquisition of Immunofluorescence Images: Algorithms and Evaluation

In this paper, we report our experience in the development of a system for automatic acquisition of immuno-fluorescence assay (IFA) images. We focus on two basic issues. Firstly, we determine an autofocus function that can deal with photobleaching, a physical phenomenon affecting automatic acquisition of IFA images, and present a set of experiments on real images that confirm its effectiveness. Secondly, we discuss if the physicians may reliably use digital IFA images in place of direct microscope observations to carry out the diagnosis. In this respect, we present the results of a preliminary experiment where physicians perform the diagnosis on a set of images both by looking directly to them at the fluorescence microscope and by looking at digital images on the screen of a workstation

Clinical comparison of QUANTA Flash dsDNA chemiluminescent immunoassay with four current assays for the detection of anti-dsDNA autoantibodies.

Introduction. The objective of the present study was to compare QUANTA Flash dsDNA, a chemiluminescent immunoassay (CIA) on the BIO-FLASH, a rapid-response chemiluminescent analyzer, to three other anti-dsDNA antibody assays and to Crithidia luciliae indirect immunofluorescence test (CLIFT). Methods. In the first part of the study, 161 samples, 61 from patients suffering from systemic lupus erythematosus (SLE) and 100 from a disease control group, were tested by QUANTA Flash dsDNA CIA, QUANTA Lite dsDNA SC ELISA, BioPlex 2200 multiplex flow immunoassay (MFI), ImmuLisa dsDNA ELISA, and NOVA Lite CLIFT. A second cohort of 69 SLE patients was then tested by QUANTA Flash dsDNA and CLIFT to expand the study. Results. The overall qualitative agreements varied between 77.0% (NOVA Lite CLIFT versus QUANTA Lite) and 89.4% (ImmuLisa versus NOVA Lite CLIFT). The clinical sensitivities for the anti-dsDNA antibody tests varied from 8.2% (NOVA Lite CLIFT) to 54.1% (QUANTA Lite), while the clinical specificities varied from 88.0% (BioPlex 2200) to 100.0% (NOVA Lite CLIFT). Good correlation was found between QUANTA Flash dsDNA and NOVA Lite CLIFT. Conclusion. Significant variations among dsDNA methods were observed. QUANTA Flash dsDNA provides a good combination of sensitivity and specificity for the diagnosis of SLE and good agreement to CLIFT.

Angiogenic cytokines in patients undergoing antiviral treatment for chronic hepatitis C virus infection.

During chronic liver disease (CLD), angiogenesis participates in the fibrogenic process. Herein, we aimed at verifying the on-treatment kinetics of serum vascular endothelial growth factor (VEGF) and angiopoietin-2 (Ang-2) in hepatitis C virus (HCV) patients undergoing antiviral therapy. Forty-three HCV patients treated with pegylated-interferon/ribavirin and 26 controls were studied. Serum VEGF and Ang-2 were determined before treatment, at different time points during treatment, and at follow-up after treatment. Thirty and 13 patients were sustained virological responder (SVR) and No-SVR, respectively. Patients showed increased Ang-2 levels [504 (368-720) versus 449 (389-483) pg/mL, P < 0.05], and equivalent VEGF levels [271 (193-377) versus 274 (199-324) pg/mL, P = 0.6], with respect to controls. By univariate analysis, stage of fibrosis was associated with Ang-2 levels (odds ratio 4.25, P < 0.05). In SVR patients VEGF levels showed a progressive reduction (P < 0.05) but returned to pretherapy levels at follow-up, and Ang-2 levels showed an opposite progressive increase, being significantly reduced at follow-up (P < 0.01). No significant modifications in VEGF and Ang-2 levels were observed in No-SVR. We conclude that, in patients with HCV-CLD, Ang-2 serum levels are associated with fibrosis and reduced at follow-up in SVR patients. On-treatment, VEGF and Ang-2 serum levels undergo different-sided modifications only in SVR patients, possibly expressing the vascular remodeling occurring early after viral clearance.

Auditory pathway in rheumatoid arthritis. A comparative study and surgical perspectives

Conclusion. Rheumatoid arthritis (RA) patients present with both conductive and sensorineural deafness. Objective. To evaluate the prevalence and features of hearing impairment in patients with RA. Material and methods. A total of 28 RA patients underwent a rheumatological evaluation, including determination of rheumatoid factor, protein 2-glycoprotein I level and the Lee index. An audiological assessment consisting of pure-tone audiometry (PTA) and determination of auditory brainstem responses (ABRs) and transient evoked otoacoustic emissions (TEOAEs) was performed. The results were compared with those of 28 age- and sex-matched healthy subjects. Four selected RA patients underwent stapedectomy; PTA and TEOAEs were evaluated 6 months postoperatively. Results. Increased air conduction thresholds at 250, 500 and 1000 Hz were found in RA subjects in comparison to controls (p<0.001). RA patients showed higher air–bone gaps in PTA (p<0.05) and an increased Wave I latency in ABRs (p=0.03). Decreased reproducibility (p<0.001) and amplitude (p<0.001) of TEOAEs were found in RA subjects in comparison to controls. A significant correlation between disease duration and echo amplitude was noticed (r=0.389). After stapedectomy, a reduction in the air–bone conduction gap (11 vs 2 dB HL) was noticed; no significant difference in TEOAEs was found.

The classification of Crithidia luciliae immunofluorescence test (CLIFT) using a novel automated system

IntroductionIn recent years, there has been an increased demand for computer-aided diagnosis (CAD) tools to support clinicians in the field of indirect immunofluorescence. To this aim, academic and industrial research is focusing on detecting antinuclear, anti-neutrophil, and anti-double-stranded (anti-dsDNA) antibodies. Within this framework, we present a CAD system for automatic analysis of dsDNA antibody images using a multi-step classification approach. The final classification of a well is based on the classification of all its images, and each image is classified on the basis of the labeling of its cells.MethodsWe populated a database of 342 images—74 positive (21.6%) and 268 negative (78.4%)— belonging to 63 consecutive sera: 15 positive (23.8%) and 48 negative (76.2%). We assessed system performance by using k-fold cross-validation. Furthermore, we successfully validated the recognition system on 83 consecutive sera, collected by using different equipment in a referral center, counting 279 images: 92 positive (33.0%) and 187 negative (67.0%).ResultsWith respect to well classification, the system correctly classified 98.4% of wells (62 out of 63). Integrating information from multiple images of the same wells recovers the possible misclassifications that occurred at the previous steps (cell and image classification). This system, validated in a clinical routine fashion, provides recognition accuracy equal to 100%.ConclusionThe data obtained show that automation is a viable alternative for Crithidia luciliae immunofluorescence test analysis.

The inter-observer reading variability in anti-nuclear antibodies indirect (ANA) immunofluorescence test: A multicenter evaluation and a review of the literature

Recently there has been an increase demand for Computer-Aided Diagnosis (CAD) tools to support clinicians in the field of Indirect ImmunoFluorescence (IIF), as the novel digital imaging reading approach can help to overcome the reader subjectivity. Nevertheless, a large multicenter evaluation of the inter-observer reading variability in this field is still missing. This work fills this gap as we evaluated 556 consecutive samples, for a total of 1679 images, collected in three laboratories with IIF expertise using HEp-2 cell substrate (MBL) at 1:80 screening dilution according to conventional procedures. In each laboratory, the images were blindly classified by two experts into three intensity classes: positive, negative, and weak positive. Positive and weak positive ANA-IIF results were categorized by the predominant fluorescence pattern among six main classes. Data were pairwise analyzed and the inter-observer reading variability was measured by Cohens kappa test, revealing a pairwise agreement little further away than substantial both for fluorescence intensity and for staining pattern recognition (k=0.602 and k=0.627, respectively). We also noticed that the inter-observer reading variability decreases when it is measured with respect to a gold standard classification computed on the basis of labels assigned by the three laboratories. These data show that laboratory agreement improves using digital images and comparing each single human evaluation to potential reference data, suggesting that a solid gold standard is essential to properly make use of CAD systems in routine work lab.