1
|
Carbone T, Pafundi V, Ciardo V, Infantino M, Muscella A, D'Angelo S. Harmonization of ANA testing challenge: quantification strategy to accurately predict end-point titers avoiding serial dilution. Immunol Res 2024; 72:96-102. [PMID: 37792145 DOI: 10.1007/s12026-023-09417-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 08/18/2023] [Indexed: 10/05/2023]
Abstract
Despite the advantages of automated systems for antinuclear antibody (ANA) analysis, the prediction of end-point titers avoiding serial dilutions is still in progress. The aims of this study were to set a conversion table providing discriminant ranges of fluorescence signal intensity values (FI) corresponding to the end-point titers and validate this tool in a real-life laboratory setting. Eight hundred ninety-four serum samples were analyzed for ANA using Image Navigator System. In order to classify FI into non-overlapping groups corresponding to conventional end-point titers, statistical discriminant analysis was used. Validation study was performed calculating agreement and error rates between visual readings and conversion table of 1119 routine ANA positive samples. Setting of FI ranges corresponding to the end-point titers for different staining patterns was computed. For samples showing single pattern, the overall agreement between visual readings and conversion table was 98.4% for all titers ranging from 1:160 to 1:2560, of which 68.0% had the same titer and 30.4% were within ± one titer difference. Concordance rates according to ANA patterns were as follows: (1) nuclear 98.4%, of which 67.0% had the same titer and 31.4% ± one titer; (2) cytoplasmic 100%, of which 72.7% had the same titer and 27.3% than ± one titer; (3) mitotic 66.6%, of which 33.3% had more ± one titer. Our study developed a quantification method for autoantibodies titers assessment based on just one single sample dilution instead of traditional serial dilution approach, providing significant advantages in routine laboratory in terms of reduction in hand-on time and harmonization of results.
Collapse
Affiliation(s)
- Teresa Carbone
- Immunopathology Laboratory, San Carlo Hospital, Potito Petrone St., 85100, Potenza, Italy
| | - Vito Pafundi
- Immunopathology Laboratory, San Carlo Hospital, Potito Petrone St., 85100, Potenza, Italy.
| | - Vito Ciardo
- Department of Biological and Environmental Science and Technologies, University of Salento, Lecce, Italy
| | - Maria Infantino
- Laboratorio Immunologia Allergologia, San Giovanni Di Dio Hospital, Firenze, Italy
| | - Antonella Muscella
- Department of Biological and Environmental Science and Technologies, University of Salento, Lecce, Italy
| | - Salvatore D'Angelo
- IReL - Rheumatology Institute of Lucania - San Carlo Hospital, Potenza, Italy
| |
Collapse
|
2
|
Zeng J, Gao X, Gao L, Yu Y, Shen L, Pan X. Recognition of rare antinuclear antibody patterns based on a novel attention-based enhancement framework. Brief Bioinform 2024; 25:bbad531. [PMID: 38279651 PMCID: PMC10818137 DOI: 10.1093/bib/bbad531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 12/17/2023] [Accepted: 12/19/2023] [Indexed: 01/28/2024] Open
Abstract
Rare antinuclear antibody (ANA) pattern recognition has been a widely applied technology for routine ANA screening in clinical laboratories. In recent years, the application of deep learning methods in recognizing ANA patterns has witnessed remarkable advancements. However, the majority of studies in this field have primarily focused on the classification of the most common ANA patterns, while another subset has concentrated on the detection of mitotic metaphase cells. To date, no prior research has been specifically dedicated to the identification of rare ANA patterns. In the present paper, we introduce a novel attention-based enhancement framework, which was designed for the recognition of rare ANA patterns in ANA-indirect immunofluorescence images. More specifically, we selected the algorithm with the best performance as our target detection network by conducting comparative experiments. We then further developed and enhanced the chosen algorithm through a series of optimizations. Then, attention mechanism was introduced to facilitate neural networks in expediting the learning process, extracting more essential and distinctive features for the target features that belong to the specific patterns. The proposed approach has helped to obtained high precision rate of 86.40%, 82.75% recall, 84.24% F1 score and 84.64% mean average precision for a 9-category rare ANA pattern detection task on our dataset. Finally, we evaluated the potential of the model as medical technologist assistant and observed that the technologist's performance improved after referring to the results of the model prediction. These promising results highlighted its potential as an efficient and reliable tool to assist medical technologists in their clinical practice.
Collapse
Affiliation(s)
- Junxiang Zeng
- Department of Clinical Laboratory, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Faculty of Medical Laboratory Science, College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Institute of Artificial Intelligence Medicine, Shanghai Academy of Experimental Medicine, Shanghai, China
| | - Xiupan Gao
- Department of Clinical Laboratory, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Limei Gao
- Department of Immunology and Rheumatology, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Youyou Yu
- Department of Clinical Laboratory, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lisong Shen
- Department of Clinical Laboratory, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Faculty of Medical Laboratory Science, College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Institute of Artificial Intelligence Medicine, Shanghai Academy of Experimental Medicine, Shanghai, China
| | - Xiujun Pan
- Department of Clinical Laboratory, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
3
|
Liu X, Xiao H, Chao J, Jian S, Wu X, Lu J, Wang J, Chen C, Liu Y. Polyvalent passive vaccine candidates from egg yolk antibodies (IgY) of important outer membrane proteins (PF1380 and ExbB) of Pseudomonas fluorescens in fish. FISH & SHELLFISH IMMUNOLOGY 2023; 143:109211. [PMID: 37944683 DOI: 10.1016/j.fsi.2023.109211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 10/22/2023] [Accepted: 11/02/2023] [Indexed: 11/12/2023]
Abstract
Polyvalent antibodies can resist multiple bacterial species, and immunoglobulin Y (IgY) antibody can be economically prepared in large quantities from egg yolk; further, IgY polyvalent antibodies have application value in aquaculture. The outer membrane proteins (OMPs) PF1380 and ExbB of Pseudomonas fluorescens were expressed and purified, and the corresponding IgY antibodies were prepared. PF1380, ExbB, and the corresponding IgY antibodies could activate the innate immune responses of chicken and Carassius auratus. The passive immunization to C. auratus showed that the IgY antibodies of PF1380 and ExbB had an immune protection rate, down-regulated the expression of antioxidant-related factors (MDA, SOD, GSH-Px, and CAT) to reduce the antioxidant reaction, down-regulated the expression of inflammation-related genes (IL-6, IL-8, TNF-α, and IL-1β) to reduce the inflammatory reaction, maintained the integrity of visceral tissue structure, and reduced apoptosis and damage of tissue cells in relation to P. fluorescens and Aeromonas hydrophila infections. Thus, the IgY antibodies of PF1380 and ExbB could be considered as passive polyvalent vaccine candidates in aquaculture.
Collapse
Affiliation(s)
- Xiang Liu
- Anhui Province Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, Fuyang Normal University, Fuyang, 236041, China; Chinese-German Joint Institute for Natural Product Research, College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723000, China; Fuyang Normal University--Funan Rural Revitalization Collaborative Technology Service Center, Fuyang Normal University, Fuyang, 236041, China.
| | - Huihui Xiao
- Anhui Province Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, Fuyang Normal University, Fuyang, 236041, China; Fuyang Normal University--Funan Rural Revitalization Collaborative Technology Service Center, Fuyang Normal University, Fuyang, 236041, China
| | - Jia Chao
- Anhui Province Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, Fuyang Normal University, Fuyang, 236041, China; Chinese-German Joint Institute for Natural Product Research, College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723000, China
| | - Sijie Jian
- Chinese-German Joint Institute for Natural Product Research, College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, 723000, China
| | - Xiaoqing Wu
- Anhui Province Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, Fuyang Normal University, Fuyang, 236041, China
| | - Juan Lu
- Fuyang Normal University--Funan Rural Revitalization Collaborative Technology Service Center, Fuyang Normal University, Fuyang, 236041, China
| | - Juan Wang
- Fuyang Normal University--Funan Rural Revitalization Collaborative Technology Service Center, Fuyang Normal University, Fuyang, 236041, China
| | - Chunlin Chen
- Fuyang Normal University--Funan Rural Revitalization Collaborative Technology Service Center, Fuyang Normal University, Fuyang, 236041, China
| | - Yong Liu
- Anhui Province Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province Key Laboratory of Environmental Hormone and Reproduction, Fuyang Normal University, Fuyang, 236041, China; Fuyang Normal University--Funan Rural Revitalization Collaborative Technology Service Center, Fuyang Normal University, Fuyang, 236041, China.
| |
Collapse
|
4
|
Zhang M, Zhang X. An indirect comparison of automated indirect immunofluorescence vs automated solid-phase immunoassays for antinuclear antibody detection: A meta-analysis and adjusted indirect comparison of diagnostic test accuracy. Int J Rheum Dis 2022; 25:991-1002. [PMID: 35726725 DOI: 10.1111/1756-185x.14369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/05/2022] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The primary aim of this study was to conduct a meta-analysis to compare the diagnostic accuracy of automated indirect immunofluorescence (automated-IIF) and fully automated solid-phase immunoassays (solid-phase assays), compared with gold standard conventional manual indirect immunofluorescence (manual-IIF) for antinuclear antibody (ANA) detection. METHODS Indirect meta-comparison was performed using prospective studies reporting comparative data between automated-IIF and fully automated solid-phase assays individually to conventional manual-IIF. Diagnostic tests regarding different automated solid-phase assays and automated-IIF for ANA detection were retrieved from the Cochrane Library, PubMed, Embase, Web of Science, Chinese Biological Medicine Database (CBM), China National Knowledge Infrastructure (CNKI), and WANFANG electronic databases from their inception to January 2022. Assessment of the quality of the studies was undertaken using a second version of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The investigated diagnostic indices including pooled sensitivity, pooled specificity, pooled positive likelihood ratio (PLR), pooled negative likelihood ratio (NLR), pooled diagnostic odds ratio (DOR), area under the summary receiver operating characteristic (AUC) of automated-IIF and solid-phase assays, respectively. Relative diagnostic odds ratio (RDOR) was calculated to indirectly compare the diagnostic accuracy of automated-IIF and solid-phase assays. To visualize results, we provide forest plots showing the RDOR with 95% confidence intervals (CI) of the 2 methods against the "gold standard" manual-IIF by R software. Deeks' funnel was used to investigate the publication bias. RESULTS A total of 16 studies involving 6111 subjects were included in the analysis. The pooled sensitivity, pooled specificity, pooled PLR, pooled NLR, pooled DOR and the AUC were 0.85 (95% CI: 0.84-0.86), 0.82 (95% CI 0.81-0.84), 14.22 (95% CI 8.55-23.65), 0.06 (95% CI 0.03-0.12), 287.0 (95% CI 124.30-662.68) and 0.983 for automated-IIF respectively, and as for solid-phase assays those were 0.73 (95% CI 0.70-0.75), 0.87 (95% CI 0.85-0.89), 5.66 (95% CI 3.33-9.62), 0.30 (95% CI 0.20-0.47), 19.14 (95% CI 8.00-45.79) and 0.894. The results of indirect comparison indicated that automated-IIF had statistically significant higher accuracy for the detection of ANA. CONCLUSION This meta-analysis and indirect comparison suggest that automated-IIF should be recommended as an alternative assay for ANA screening under the condition of increased demand for ANA testing in clinical immunology laboratories.
Collapse
Affiliation(s)
- Minjie Zhang
- Department of Medical Laboratory, Xianyang Central Hospital, Xianyang, China
| | - Xiaoyan Zhang
- Department of Medical Laboratory, Yan'an People's Hospital, Yan'an, China
| |
Collapse
|
5
|
Theodoraki E, Orfanoudaki E, Foteinogiannopoulou K, Andreou NP, Gazouli M, Koutroubakis IE. Effect of antinuclear antibodies on pharmacokinetics of anti-TNF therapy in patients with inflammatory bowel disease. Int J Colorectal Dis 2022; 37:639-646. [PMID: 35013823 DOI: 10.1007/s00384-021-04091-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/28/2021] [Indexed: 02/04/2023]
Abstract
PURPOSE The detection of antinuclear antibodies (ANA) in serum of patients with inflammatory bowel disease (IBD) has been associated with a worse response to anti-TNF therapy and the development of cutaneous or arthritic manifestations. The aim of this study was to investigate a possible association of serum ANA with infliximab (IFX) and adalimumab (ADA) trough levels (TLs) and anti-drug antibodies in IBD patients treated with IFX or ADA. METHODS Consecutive IBD patients under maintenance therapy with IFX or ADA in whom there was at least one available measurement of anti-TNF TLs, antibodies to IFX or ADA, and ANA in serum were included. The correlation of ANA positivity with demographics, clinical characteristics, treatment, TLs and anti-drug antibodies, of all patients was analyzed. RESULTS One hundred two IBD patients under maintenance therapy with IFX or ADA were enrolled. Of these, 53 (52%) were ANA positive with 28 (27.5%) positive also to anti-ds-DNA in serum. In the univariate analysis ANA positivity was found to be correlated with age (P = 0.008), female gender (P = 0.03), duration of treatment (P = 0.06), arthralgias (P = 0.04) and TLs (P = 0.005). However, in multivariate logistic regression analysis only age and TLs remained significantly associated with the presence of ANA positivity (P = 0.04 and P = = 0.006, respectively). No significant association of ANA positivity with the development of cutaneous or rheumatological manifestations was found. CONCLUSIONS In IBD patients under maintenance therapy with anti-TNF ANA positivity is associated with lower TLs. The clinical significance of this finding remains to be defined in future larger prospective studies.
Collapse
Affiliation(s)
- Eirini Theodoraki
- Department of Gastroenterology, Medical School, University Hospital of Heraklion, University of Crete, P.O. BOX 1352, 71110, Heraklion, Crete, Greece
| | - Eleni Orfanoudaki
- Department of Gastroenterology, Medical School, University Hospital of Heraklion, University of Crete, P.O. BOX 1352, 71110, Heraklion, Crete, Greece
| | - Kalliopi Foteinogiannopoulou
- Department of Gastroenterology, Medical School, University Hospital of Heraklion, University of Crete, P.O. BOX 1352, 71110, Heraklion, Crete, Greece
| | - Nikolaos-Panagiotis Andreou
- Department of Basic Medical Sciences, Laboratory of Biology, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Gazouli
- Department of Basic Medical Sciences, Laboratory of Biology, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Ioannis E Koutroubakis
- Department of Gastroenterology, Medical School, University Hospital of Heraklion, University of Crete, P.O. BOX 1352, 71110, Heraklion, Crete, Greece.
| |
Collapse
|
6
|
Kolev M, Horn MP, Semmo N, Nagler M. Rational development and application of biomarkers in the field of autoimmunity: A conceptual framework guiding clinicians and researchers. J Transl Autoimmun 2022; 5:100151. [PMID: 35309737 PMCID: PMC8927991 DOI: 10.1016/j.jtauto.2022.100151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/04/2022] [Accepted: 03/05/2022] [Indexed: 11/26/2022] Open
Abstract
Clear guidance is needed in the development and implementation of laboratory biomarkers in medicine. So far, no standardized phased approach is established that would pilot researchers and clinicians in this process. This leads to often incompletely validated biomarkers, which can bear the consequence of wrong applications, misinterpretation and inadequate management in the clinical context. In this conceptual article, we describe a stepwise approach to develop and comprehensively validate laboratory biomarkers. We will delineate basic steps including technical performance, pre-analytical issues, and biological variation, as well as advanced aspects of biomarker utility comprising interpretability, diagnostic and prognostic accuracy, and health-care outcomes. These aspects will be illustrated by using well-known examples from the field of immunology. The application of this conceptual framework will guide researchers in conducting meaningful projects to develop and evaluate biomarkers for the use in clinical practice. Furthermore, clinicians will be able to adequately interpret pre-clinical and clinical diagnostic literature and rationally apply biomarkers in clinical practice. Improvement in the implementation and application of biomarkers might relevantly change the management and outcomes of our patients for the better.
Collapse
|
7
|
Wener MH, Fink SL, Morishima C, Chaudhary A, Hutchinson K. Anti-Nuclear Antibody Quantitation: Calibration and Harmonization Adjustment via Population Interrogation. J Appl Lab Med 2022; 7:46-56. [PMID: 34996081 DOI: 10.1093/jalm/jfab142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/21/2021] [Indexed: 11/14/2022]
Abstract
BACKGROUND The 2019 classification criteria for systemic lupus erythematosus (SLE) includes an initial criterion requiring the presence of an antinuclear antibody (ANA), positive at a titer of at least 1:80 on HEp-2 cells, or equivalent. However, results of ANA tests performed on HEp-2 cells vary when tested in different laboratories. Calibration of ANA assays by achieving a common specificity in healthy control populations offers the possibility of achieving harmonization via population interrogation, but the expected specificity in a healthy control population is not known. METHODS The studies used to determine the use of ANAs performed by immunofluorescence microscopy on HEp-2 cells as the entry criterion for classification of SLE were reanalyzed by a meta-analysis to determine the expected frequency of positive ANAs in healthy control populations at serum dilutions of 1:40 and 1:80. RESULTS Our meta-analysis demonstrated that the expected specificity in a healthy control population of ANA performed using serum diluted 1:80 is 91.3% (CI 86.1-94.7%). The expected specificity of ANA performed at 1:40 serum dilution is 79.2% (CI 72.3-84.8%). CONCLUSION One approach to achieving harmonization of ANA assays from different laboratories with each other and with expected performance would involve adjusting assays so that about 10% of a healthy control population has a positive ANA when tested at 1:80 dilution, and about 20% of the healthy control population has a positive ANA when tested at 1:40 dilution. This pragmatic approach to calibration and harmonization adjustment via population interrogation offers an opportunity for individual laboratories to be aligned with each other and with ANA performance expected for consistent categorization of patients with SLE.
Collapse
Affiliation(s)
- Mark H Wener
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA
- Rheumatology Division, Department of Medicine, University of Washington, Seattle, WA
| | - Susan L Fink
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA
| | - Chihiro Morishima
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA
| | - Anu Chaudhary
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA
| | - Kathleen Hutchinson
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA
| |
Collapse
|
8
|
Röber N, Dellavance A, Ingénito F, Reimer ML, Carballo OG, Conrad K, Chan EKL, Andrade LEC. Strong Association of the Myriad Discrete Speckled Nuclear Pattern With Anti-SS-A/Ro60 Antibodies: Consensus Experience of Four International Expert Centers. Front Immunol 2021; 12:730102. [PMID: 34675922 PMCID: PMC8524051 DOI: 10.3389/fimmu.2021.730102] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 09/13/2021] [Indexed: 11/26/2022] Open
Abstract
Introduction The morphological patterns in indirect immunofluorescence assay on HEp-2 cells (HEp-2 IFA) reflect the autoantibodies in the sample. The International Consensus on ANA Patterns (ICAP) classifies 30 relevant patterns (AC-0 to AC-29). AC-4 (fine speckled nuclear pattern) is associated to anti-SS-A/Ro, anti-SS-B/La, and several autoantibodies. Anti-SS-A/Ro samples may contain antibodies to Ro60 and Ro52. A variation of AC-4 (herein designated AC-4a), characterized by myriad discrete nuclear speckles, was reported to be associated with anti-SS-A/Ro. The plain fine speckled pattern (herein designated AC-4b) seldom was associated with anti-SS-A/Ro. This study reports the experience of four expert laboratories on AC-4a and AC-4b. Methods Anti-Ro60 monoclonal antibody A7 was used to investigate the HEp-2 IFA pattern. Records containing concomitant HEp-2 IFA and SS-A/Ro tests from Durand Laboratory, Argentina (n = 383) and Fleury Laboratory, Brazil (n = 144,471) were analyzed for associations between HEp-2 IFA patterns and disease-associated autoantibodies (DAA): double-stranded DNA, Scl-70, nucleosome, SS-B/La, Sm, and U1-RNP. A total of 381 samples from Dresden Technical University (TU-Dresden), Germany, were assayed for HEp-2 IFA and DAA. Results Monoclonal A7 recognized Ro60 in Western blot and immunoprecipitation, and yielded the AC-4a pattern on HEp-2 IFA. Analyses from Durand Laboratory and Fleury Laboratory yielded compatible results: AC-4a was less frequent (8.9% and 2.7%, respectively) than AC-4b (26.1% and 24.2%) in HEp-2 IFA-positive samples. Reactivity to SS-A/Ro occurred in 67.6% and 96.3% of AC-4a-pattern samples against 23% and 6.8% of AC-4b pattern samples. Reciprocally, AC-4a occurred in 24% and 47.1% of anti-SS-A/Ro-positive samples, and in 3.8% and 0.1% of anti-SS-A/Ro-negative samples. Data from TU-Dresden show that the AC-4a pattern occurred in 69% of 169 anti-SS-A/Ro-monospecific samples (62% of all anti-SS-A/Ro-positive samples) and in 4% of anti-SS-A/Ro-negative samples, whereas anti-SS-A/Ro occurred in 98.3% of AC-4a samples and in 47.9% of AC-4b samples. In all laboratories, coexistence of anti-SS-B/La, but not other DAA, in anti-SS-A/Ro-positive samples did not disturb the AC-4a pattern. AC-4a was predominantly associated with anti-Ro60 antibodies. Conclusions This study confirms the association of AC-4a pattern and anti-SS-A/Ro in opposition to the AC-4b pattern. The results of four international expert laboratories support the worldwide applicability of these AC-4 pattern variants and their incorporation into ICAP classification under codes AC-4a and AC-4b, respectively. The AC-4 pattern should be maintained as an umbrella pattern for cases in which one cannot discriminate AC-4a and AC-4b patterns. The acknowledgment of the AC-4a pattern should add value to HEp-2 IFA interpretation.
Collapse
Affiliation(s)
- Nadja Röber
- Institute of Immunology, Technical University Dresden, Dresden, Germany
| | - Alessandra Dellavance
- Division of Research and Development, Fleury Medicine and Health Laboratories, São Paulo, Brazil
| | | | | | | | - Karsten Conrad
- Institute of Immunology, Technical University Dresden, Dresden, Germany
| | - Edward K L Chan
- Department of Oral Biology, University of Florida, Gainesville, FL, United States
| | - Luis E C Andrade
- Division of Immunology, Fleury Medicine and Health Laboratories, São Paulo, Brazil.,Division of Rheumatology, Universidade Federal de São Paulo, São Paulo, Brazil
| |
Collapse
|