Anti-DFS70 antibodies have been recently included in a new testing algorithm for patients with suspicion of connective tissue diseases (CTDs). This algorithm enables to assess the probability of ...having a CTD in patients with a positive antinuclear antibodies (ANA) result. The aim of the study was to analyze the the inter-method agreement between three different HEp-2 cell substrates for anti-DFS70 detection, focusing on two novel IIF methods that assess the presence of monospecific anti-DFS70 antibodies.
Immunological and clinical records of 29 patients who were double positive for anti-DFS70 autoantibodies using chemiluminescence assay (CIA) and Immunoblot (IB) were studied. The IIF on HEp-2 cells were determined using slides from Inova Diagnostics, Euroimmun and Immco. The capability to detect isolated anti-DFS70 antibodies was compared using immunoadsorption on NOVA Lite HEp-2 Select (Inova Diagnostics) and the HEp-2 ELITE/DFS70 knockout test (Immco).
The three substrates had very good sensitivity for detecting patients with anti-DFS staining pattern (93.1%, 79.3% and 72.4% for Euroimmun, Immco and Inova respectively). Most of the patients had full inhibition of DFS pattern (65.5%) by immunoabsorption test. Also, the 55.2% of the subjects were positive for monospecific DFS pattern using HEp-2 ELITE/DFS70 knockout test. However, the correlation between the full inhibition by immunoadsorption and the monospecific DFS pattern in knockout cells was very low (kappa: 0.22).
The evaluation of monospecific anti-DFS70 antibodies is clinically fundamental and challenging using traditional HEp-2 IIF. Results obtained in this study support the hypothesis that the lack of standardization across IIF kits along with the subjectivity of user interpretation among other factors contribute to the overall reduction in the agreement.
Background and aims: Several antibodies have been reported in the sera of patients with Crohn’s disease (CD) and ulcerative colitis (UC). The most commonly described are anti-Saccharomyces cerevisiae ...mannan antibodies (ASCA) in CD and perinuclear antineutrophil cytoplasm antibodies (pANCA) in UC. Familial clustering of these antibodies has been described, suggesting they might be genetic markers. Our aim was to investigate the presence of these antibodies before the emergence of overt clinical manifestations. Methods: Since 1980, the Israeli Defense Force (IDF) Medical Corps Serum Repository has stored serum samples obtained systematically from 5% of all recruits on enlistment, and from the same population on discharge from compulsory military service. We evaluated serum samples obtained from 32 subjects with CD and eight with UC before they were clinically diagnosed, along with samples from matched controls. Results: ASCA were present in 10/32 (31.3%) CD patients before clinical diagnosis compared with 0/95 (0%) controls (p<0.001). None of the eight patients with serum samples available before diagnosis of UC were ASCA positive. ASCA was positive in 54.5% of patients after diagnosis of CD. The mean interval between ASCA detection and diagnosis was 38 months. In 90% of patients, antibodies were detected in the first available serum sample; therefore, measurements of the average time from the presence of ASCA to diagnosis may be even longer. pANCA were present in 2/8 (25%) patients with available sera before the diagnosis of UC. None of their 24 matched controls were positive (p = 0.014). Conclusions: ASCA and pANCA may predict development of inflammatory bowel disease years before the disease is clinically diagnosed.
Anti-HMGCR antibodies represent a characteristic serological feature of statin-exposed and statin-unexposed patients with immune-mediated necrotizing myopathy (IMNM). We assessed anti-HMGCR ...antibodies in patients with suspected IMNM following statin exposure and patients with other autoimmune rheumatic diseases. We evaluated the presence of anti-HMGCR autoantibodies in sera samples from 13 statin-exposed patients who were suspected of having IMNM, 38 patients with different inflammatory and autoimmune rheumatic diseases and 29 healthy subjects. The autoantibodies were evaluated by two assays: a new chemiluminescence QUANTA Flash HMGCR kit utilizing BIO-FLASH system and QUANTA Lite
®
HMGCR ELISA kit. Twelve samples from patients with suspicion for IMNM were found positive for anti-HMGCR antibodies by both assays. Only one of the 13 samples that were found positive by ELISA was negative by CIA. A very good qualitative correlation (
κ
= 0.95; 95 % CI 0.85–1.0) and quantitative agreement (Spearman’s rho 0.87;
P
value < 0.0001; 95 % CI 0.62–0.96) were found between these two assays. All samples from healthy subjects and from the disease-controlled patient cohort were negative for anti-HMGCR antibodies. In comparison with ELISA results, the CIA exhibited high sensitivity and specificity values of 92.3 and 100 %, respectively. Receiver operating characteristic analysis for CIA and ELISA yielded area under the curve values of 0.99. The presence of anti-HMGCR antibodies may be a useful biomarker of IMNM in statin-exposed patients. There is a good correlation between the two anti-HMGCR antibody assays evaluated in the present study.
Introduction/objectives
Accurate interpretation of DFS70 (dense fine speckled 70) and mixed antinuclear antibodies (ANAs) patterns can be challenging using conventional HEp-2 immunofluorescence (IIF) ...method. We evaluated a novel HEp-2 IIF substrate (HEp-2 ELITE/DFS70-KO) composed of a mixture of engineered HEp-2 devoid of the DFS70 autoantigen and conventional HEp-2 cells. The study assessed the utility of the new substrate in ANA screening and its advantages.
Method
One thousand and five consecutive routine samples sent for ANA screening were tested on both standard HEp-2 and the HEp-2 ELITE DFS70 KO substrates (ImmuGlo ANA HEp-2 and HEp-2 ELITE/DFS70-KO, Trinity Biotech, Buffalo, NY). Anti-DFS70 antibody specificity was additionally determined by immunoblot (IB). Clinical and serological data were included in the analysis of the overall impact of the novel HEp-2 substrate on DFS pattern interpretation.
Results
Of the 22 cases suspected as positive for DFS pattern alone or in combination with homogeneous or speckled patterns on conventional HEp-2 cells, 17 were interpreted with a higher accuracy using the new HEp-2 ELITE method as positive for DFS70 (monospecific DFS70 (10), mixed DFS70 (7)), speckled (3), and DFS (2) patterns.
Conclusions
The new substrate was not only useful in deciphering unclear mixed ANA patterns but also highly sensitive in detecting DFS70 pattern in comparison to the DFS70 positivity obtained using IB.
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14-3-3η protein is a proinflammatory mediator that may represent a novel diagnostic and prognostic biomarker for rheumatoid arthritis (RA). We assessed the correlation between changes ...in serum 14-3-3η levels and changes in clinical disease activity measures in RA patients treated with Tofacitinib (TOF). Paired serum samples from 35 patients with RA were obtained at baseline and 5 months after the initiation of treatment with TOF. The levels of 14-3-3η were measured by JOINT stat 14-3-3η ELISA test kits (Augurex Life Sciences Corp.). The cut-off was defined as 0.19 ng/ml. 14-3-3η positivity was found in 57% of the patients at baseline and in 37% of the patients after 5 months of treatment. Mean ± SD baseline 14-3-3η levels 4.92 ± 8.86 ng/ml were significantly higher (p < 0.005) than 14-3-3η levels following treatment 1.97 ± 4.59 ng/ml. A statistically significant improvement (p < 0.001) of CDAI, SDAI, DAS4ESR and DAS4CRP was achieved after 5 month of treatment. Decrease in 14-3-3η protein levels was highly correlated with improvement in DAS4ESR (r = 0.50, p < 0.01), DAS4CRP (r = 0.46, p < 0.01) and ESR (r = 0.36, p = 0.03) and moderately correlated with improvement in CDAI (r = 0.32, p = 0.065) and SDAI (r = 0.33, p = 0.051). The correlation between decrease in 14-3-3η levels and improvement in DAS4ESR remained significant in a partial correlation analysis controlling for ESR (r = 0.39, p = 0.02). This study demonstrates that in RA patients who were treated with TOF, decrease in 14-3-3η levels is correlated with improvement in clinical disease activity parameters. The 14-3-3η protein may serve as an objective biomarker for monitoring of TOF therapy response.
Objective: To evaluate traditional and non-traditional risk factors for subclinical atherosclerosis in systemic lupus erythematosus (SLE). Methods: A prospective cohort of 78 patients with SLE ...without overt atherosclerotic disease was studied. SLE clinical and laboratory parameters, disease activity and damage, treatment and traditional risk factors for atherosclerosis were evaluated. At baseline (T1) and after five years’ follow up (T2), the serum levels of anti-oxidised palmitoyl arachidonoyl phosphocholine (oxPAPC), anti-heat shock protein 65, and anti-β2-glycoprotein I antibodies and C reactive protein were tested. At T2, intima-media thickness (IMT) was measured using duplex carotid sonography. Thickened intima, plaque, mean IMT (m-IMT), and maximum IMT (M-IMT) were assessed. Results: A thickened intima was seen in 22/78 (28%) patients and plaque in 13/78 (17%). M-IMT and m-IMT were (mean (SD)) 0.77 (0.34) mm and 0.55 (0.15) mm, respectively. Patients with carotid abnormalities were significantly older, had higher blood pressure and total serum cholesterol levels, and had taken a higher prednisone cumulative dosage than those without any lesions. The carotid abnormalities were associated with renal disease and ECLAM >2 at T1, and with azathioprine treatment. In multivariate analysis, age and cumulative prednisone dose were associated with carotid abnormalities; age, hypertension, and anti-oxPAPC at T2 were correlated with higher M-IMT and m-IMT. Conclusions: In patients with SLE some non-traditional risk factors for atherosclerosis were identified, the most important of which was the cumulative prednisone dose. The role of some traditional risk factors, such as age and hypertension, was also confirmed. The predictive value of the new immunological and inflammatory markers of atherosclerosis seems to be masked by some disease related features.
: The BioPlex™ 2200 ANA Screen is a fully automated system that determines levels for 13 different autoimmune antibodies of established clinical significance. The objective of this study was to ...determine the specificity of the BioPlex™ 2200 ANA Screen assay and to analyze the antibody profile samples collected from healthy subjects against comparative ELISA and IIF screening methods. A total of 510 specimens were randomly selected from a cohort of apparently healthy blood bank donors. Samples were distributed to five age brackets. All samples were tested using Bio‐Rad's ANA Screen kit. Specificity was compared to IIF and ELISA results. Most of the samples were found negative in all ANA screening systems (84.5% by IIF, 92.5% by BioPlex™ 2200 ANA Screen kit, and 94.5% by ELISA). The frequency of positive results was highest (15.5%) using IIF, in comparison to almost similar results (5.5% vs. 7.5%) achieved by ANA ELISA and BioPlex™ 2200 ANA Screen kits. The positive rate of autoantibodies was significantly reduced when analyzed by different combinations of ANA screen assays (from 2.35% using IIF + BioPlex ANA Screen tests to 0.98% by using all three tests). Using the BioPlex™ 2200 ANA Screen system, we were able to identify samples with high levels of individual antibodies: anti‐dsDNA at 20‐63/IU/mL, antichromatin at 4–8 AI, anti‐SmRNP at 2–6 AI, and anti‐RNPA at 2‐4.5 AI. Importantly, from 7 IIF and ELISA positive sera, 5 of these were also BioPlex 2200 positive, suggesting that the BioPlex is seeing the samples that are of the greatest interest, using the established techniques. The specificity of the BioPlex 2200 ANA Screen analysis of 13 different analytes (dsDNA, centromere B, chromatin, Jo1, ribosomal P, RNP 68, RNP A, Scl‐70, Sm, SmPNP, SS‐A52, SS‐A60, SS‐B) is comparable (P < 0.252) to the ELISA ANA screening test. Like the ELISA, the BioPlex 2200 has a lower (P < 0.001) positive rate than IIF for the autoantibody screening.
Indirect immunofluorescence (IIF) is the main technique for the detection of antinuclear antibodies (ANA) and antineutrophil cytoplasmic antibodies (ANCA). The fully automated IIF processor HELIOS
®
...is the first IIF processor that is able to automatically prepare slides and perform automatic reading. The objective of the present study was to determine the diagnostic performance of this system for ANA and ANCA IIF interpretation, in comparison with visual IIF. ANA detection by visual IIF or HELIOS
®
was performed on 425 sera samples including: 218 consecutive samples submitted to a reference laboratory for routine ANA testing, 137 samples from healthy subjects and 70 ANA/ENA positive samples. For ANCA determination, 170 sera samples were collected: 40 samples for routine testing, 90 samples from healthy blood donors and 40 anti-PR3/anti-MPO positive subjects. Good correlation was found for the visual and automated ANA IIF approach regarding positive/negative discrimination of these samples (kappa = 0.633 for ANA positive samples and kappa = 0.657 for ANA negative samples, respectively). Positive/negative IIF ANCA discrimination by HELIOS
®
and visual IIF revealed a complete agreement of 100 % in sera from healthy patients and PR3/MPO positive samples (kappa = 1.00). There was 95 % agreement between the ANCA IIF performed by automated and visual IIF on the investigation of routine samples. Based on these results, HELIOS
®
demonstrated a high diagnostic performance for the automated ANA and ANCA IIF interpretation that was similar to a visual reading in all groups of samples.
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