Fine Speckled Pattern Research Articles

Evaluation of Positive Cases for Dense Fine Speckled (DFS) Immunofluorescence Pattern and Anti-DFS70 Antibodies

Objective: The detection of anti-nuclear antibodies (ANA) is crucial in diagnosing systemic autoimmune rheumatic diseases (SARDs). The Dense Fine Speckled (DFS) nuclear pattern is one of the most common indirect immunofluorescence (IIF) patterns detected during routine ANA screening in patients with various clinical conditions. The aim of this study was to analyze the data of patients who were positive for DFS/antiDFS in our patient population and to show the possible clinical relationship. Methods: In this retrospective study, 7406 patient serum samples sent to our laboratory for routine ANA screening between May 2022-2023 were evaluated for the presence of anti-DFS. Results: In a group of patients referred for routine ANA screening using the indirect immunofluorescence method, the frequency of DFS pattern was found to be 4.55% (337/7406), with ANA positivity detected at a rate of 25.68% (1902/7406). Out of 221 patients with DFS pattern, 181 tested positive for anti-DFS antibodies in both the IIF-ANA and immunoblot (IB) tests. Additionally, 11 of these patients tested positive for other antibodies against different extractable nuclear antigens (anti-ENAs). Conversely, only seven out of the 40 patients who tested negative for anti-DFS antibodies showed positive results for other anti-ENAs. Conclusion: The DFS pattern is often positive in individuals. In patients exhibiting this pattern, anti-DFS70 antibody may be detected alone or in combination with SARD-associated autoantibodies. Therefore, we propose that in this patient cohort, it would be more prudent to screen for additional concomitant autoantibodies with anti-ENA rather than confirming isolated anti-DFS. doi: https://doi.org/10.12669/pjms.41.2.10336 How to cite this: Gurbuz M, Yıldırım BF, Cetinkol Y. Evaluation of Positive Cases for Dense Fine Speckled (DFS) Immunofluorescence Pattern and Anti-DFS70 Antibodies. Pak J Med Sci. 2025;41(2):580-584. doi: https://doi.org/10.12669/pjms.41.2.10336 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Examination of antinuclear antibody staining patterns and titers in patients with childhood-onset systemic lupus erythematosus.

Antinuclear antibodies (ANA) staining patterns can provide useful information in systemic lupus erythematosus (SLE). In our study, we examined the frequency of ANA staining patterns in disease-related features in childhood-onset SLE patients. ANA and its staining patterns were assessed in childhood-onset SLE patients. Two hundred twenty-three patients were included (F/M = 3/1). Their median age at diagnosis was 14.3 (11.9-16.1) years. The anti-cell (AC)-4/5 (fine or large speckled) pattern was the most common nuclear ANA pattern (75.8%), while the AC-19 (dense fine speckled) pattern was the most frequently detected cytoplasmic ANA pattern (13.1%). The AC-4/5 (fine or large speckled) patterns were notably seen in fever, acute and chronic cutaneous lupus, arthritis, serositis, hematologic involvement, renal involvement, neuropsychiatric involvement, gastrointestinal involvement, and cardiopulmonary involvement (all p < .001). Conversely, the AC-1 (homogeneous) pattern was significantly detected in oral/nasal ulcers and non-scarring alopecia (both p < .001). Regarding the laboratory features, the AC-4/5 (fine or large speckled) patterns exhibited a predominant seen in autoimmune hemolytic anemia, leukopenia, thrombocytopenia, elevated ESR and CRP, hypocomplementemia, direct Coombs, anti-Smith (Sm), anti-SSA and SS-B, anti-ribonucleoprotein (RNP), anti-histone, anti-ribosomal P, lupus anticoagulant, anti-cardiolipin immunoglobulin (Ig)M/IgG, and anti-β2-glycoprotein IgM/IgG positivities (all p < .001). In contrast, the AC-1 (homogeneous) pattern was detected in anti-double-stranded (ds) DNA and anti-histone positivity (both p < .001). Our study showed that AC-4/5 and AC-1 patterns of ANA are frequently detected in many clinical and serological features of childhood-onset SLE patients. However, further studies are needed in larger populations to verify these results.

Clinical relevance and frequency of cytoplasmic patterns observed in ANA-Hep-2: experience of Cairo University Hospitals.

Antinuclear antibodies (ANA) are the most common biomarkers observed in autoimmune diseases. Cytoplasmic staining patterns on ANA-Hep-2 are gaining recognition but with scanty information about their clinical and diagnostic role. The aim is to assess the frequency of cytoplasmic ANA patterns in autoimmune diseases, and to evaluate their possible associations with clinical diagnoses and autoantibodies. This observational cross-sectional study was conducted by examining and/or reviewing ANA by indirect immunofluorescence assay during a 13-month period. This was followed by testing the group of patients with a positive cytoplasmic staining pattern (n = 92) using the Microblot-Array ANA plus for the presence of 44 specific autoantibodies. Out of 2741 samples, 1791 (65.3%) tested negative, 845 (30.9%) tested positive nuclear staining patterns, 56 (2.0%) positive solitary cytoplasmic staining patterns, and 49 (1.8%) positive mixed nuclear and cytoplasmic patterns. Ninety-two cases (3.4% of the total cases) were analyzed using Microblot-Array ANA plus, with reticular as the most frequent cytoplasmic pattern, followed by dense fine speckled. The most frequently associated disease with reticular pattern was primary biliary cholangitis (28.9%), and the most frequently detected autoantibodies were against M2 (66.7%). The most frequently associated disease with dense fine speckled pattern was systemic lupus erythematosus (69.4%), and the most frequently detected autoantibodies were against nucleosome (57.7%) and ribosomal P0 (53.8%). This study highlights the significance of reporting cytoplasmic staining patterns and their importance in assessment of autoimmune diseases. Larger cohort studies on treatment naïve patients are recommended.

Exposure to Gold Induces Autoantibodies against Nuclear Antigens in A.TL Mice.

To demonstrate causation or/and assess pathogenic mechanisms of environment-induced autoimmunity, various animal models that mimic the characteristics of the human autoimmune diseases need to be developed. Experimental studies in mice reveal the genetic factors that contribute to autoimmune diseases. Here, the immune response of two mouse strains congenic for non-H-2 genes, A.TL (H-2tl) and A.SW (H-2s), was evaluated after 15 weeks' exposure to gold aurothiomalate (AuTM). AuTM-treated A.TL mice showed anti-nuclear antibodies (ANA) with homogenous and/or fine speckled staining patterns and serum autoantibodies to ds-DNA, chromatin, histones, and ribonucleoproteins (RNP). Female A.TL mice showed a stronger immune response than males, as well as an increase of B cells in their spleen after 15 weeks of gold exposure. A.SW exposed for AuTM showed the induction of anti-nucleolar antibodies (ANoA) with a clumpy staining pattern, as well as an increase in splenic B and T cells. The serum autoantibodies levels in A.SW mice were limited compared to those of A.TL mice. Overall, A.TL presents a stronger immune response after gold exposure than A.SW. The immune response developed in A.TL presents similarities with the clinical manifestations in human autoimmune diseases. Thus, gold-exposed A.TL could constitute a potential experimental mouse model for the study of autoimmunity.

Analysis of Antinuclear Antibody Test Referral Patterns in a Tertiary Care Hospital over Three Years: A Retrospective Observational Study

Introduction: Antinuclear Antibodies (ANA) detection by Human Epithelial Substrate (Hep2) is the recommended screening test for the diagnosis of ANA-Associated Rheumatic Diseases (AARD). ANA is ordered by various specialists in a tertiary care hospital, and a positive ANA result is followed by testing for specific autoantibodies. High pretest probability, pattern type with intensity, and referral departments are key factors determining the autoimmune diagnosis. Aim: To analyse the ANA referral patterns among the various departments and also to estimate the prevalence and clinical significance of rare ANA patterns. Materials and Methods: A retrospective observational study was conducted at Nizam's Institute of Medical Sciences, Hyderabad, a tertiary care hospital, in Hyderabad, Telangana, India where ANA test reports (n=16,994) from various departments over three years (November 2017 to October 2020) were evaluated between November 2022 to December 2022. ANA tests were performed on Hep2 substrate at a 1:100 dilution, and ANA patterns were reported according to the International Consensus on ANA Patterns (ICAP) nomenclature. Statistical analysis of department- wise ANA positivity and fluorescence intensity was conducted, and the final diagnoses of patients with rare ANA patterns (&lt;1%) were noted from clinical records. Fischer's-exact test was used for comparing categorical variables, considering p-value &lt;0.05 as statistically significant. Results: The majority of ANA requests were from the Rheumatology department (5859; 34.5%), followed by nephrology (3132; 18.4%), neurology (1940; 11.4%), general medicine (1646; 9.7%), haematology (1106; 6.5%), and casualty (878; 5.2%), accounting for 85.6% of total referrals. The highest percentage of positivity among ANA referrals was observed in Rheumatology (333; 5.7%), with 58% of positive ANA showing 4+ intensity. No positives were observed from many surgical departments. Rare ANA patterns with a prevalence of less than 1% were observed in 22 patients with mitotic patterns accounting for the majority of rare patterns seen in 11 out of 22 (50%) cases followed by nuclear envelope, rods rings, and nuclear dense fine speckled patterns were observed in six, four, and one patient(s), respectively. The majority of rare ANA patterns had 2+ fluorescence intensity without any associated autoimmune diagnosis. Conclusion: The highest and lowest positivity among ANA referrals were observed in the rheumatology and surgical departments, respectively. Considering the pretest probability of AARD before ordering an ANA test would lead to the optimum utilisation of laboratory services. Mitotic patterns constituted the majority of rare ANA patterns and need to be clinically correlated with antibody titers.

Clinical Significance of Dense Fine Speckled Pattern: Association with Inflammatory State

Clinical Significance of Dense Fine Speckled Pattern: Association with Inflammatory State

Discriminating between Homogeneous (AC-1) and Dense Fine Speckled (AC-2) Antinuclear Antibody Patterns: Re-Evaluation of Immunofluorescence Imaging.

Antinuclear antibodies (ANAs) are essential diagnostic markers in systemic autoimmune rheumatic diseases. Among the 30 ANA patterns, homogeneous (AC-1) and dense fine speckled (AC-2) should be focused on owing to their somewhat indistinct presentation in immunofluorescence imaging and distinct correlation with clinical conditions. This study aimed to develop a flowchart to guide discrimination between AC-1 and AC-2 patterns and to re-evaluate ANA samples according to this flowchart to verify its detection ability. We re-evaluated immunofluorescence imaging of 62 ANA blood samples simultaneously subjected to solid-phase assays for autoantibodies against dsDNA, nucleosomes, histones, and DFS70. The results showed statistically significant odd ratios (ORs) of detection of anti-DFS70 using AC-2 after re-evaluation of total samples (OR 101.9, 95% CI 11.7-886.4, p-value < 0.001) and subgroup analysis of patients' samples (OR 53.8, 95% CI 5.9-493.6, p-value < 0.001). The OR of anti-nucleosome/histone/dsDNA detection using AC-1 in re-evaluated data increased to 5.43 (95% CI 1.00-29.61, p-value = 0.05). In the analysis of specific autoantibodies, more than half of the samples with an AC-2 pattern (54.2%) had specific autoantibodies other than anti-DFS70. We conclude that the flowchart for discriminating between AC-1 and AC-2 ANA patterns in this study is a viable practical guide for other laboratories when encountering equivocal ANA results.

B-073 The Clinical Utility of Reporting AC-2 Pattern With Anti-DFS70 Antibody

Abstract Background The dense fine speckled (DFS) pattern (AC-2) is often observed in antinuclear antibody (ANA) indirect immunofluorescence (IIF) assay, and the related anti-DFS70 antibody is known to be negatively associated with a systemic autoimmune rheumatic disease (SARD). Identifying the AC-2 pattern is challenging, as it could be generally confused with the AC-1, AC-4, AC-5, or AC-29 patterns displaying stained metaphase plates or speckled nuclei. Since the anti-DFS70 antibody is not included in routine autoantibody tests, the clinical utility of the AC-2 pattern and anti-DFS70 antibody is not adequately applied in the laboratory and clinical practice. We evaluated the prevalence of anti-DFS70 and other autoantibodies in samples presenting AC-2 pattern in ANA IIF assay. Additionally, we analyzed the association of anti-DFS70 antibodies and clinical features in patients with AC-2 patterns. Method We retrospectively reviewed the ANA IIF images of 1839 samples made by an automated ANA analyzer classified as AC-1, AC-2, AC-4, AC-5, and AC-29 patterns. AC-1, AC-2, AC-4, AC-5, and AC-29 patterns comprised 60.5% of all ANA positives (1839/3039). Among them, the AC-2 pattern was identified in 18.5% (341/1839) by two experts, and only 197 with residual samples were available for further evaluation. Those 197 samples were tested for anti-DFS70 antibodies with enzyme-linked immunosorbent assay (ELISA) and line immunoblot assay (LIA). They were also tested for 22 other autoantibodies (dsDNA, nucleosomes, histones, SS-A/Ro-52, SS-B, RNP/Sm, Sm, Mi-2α, Mi-2β, Ku, CENP-A, CENP-B, Sp100, PML, Scl-70, PM/Scl100, PM/Scl75, RP11, RP155, gp210, PCNA) with LIA. Clinical information from 197 patients was obtained from a retrospective review of electronic medical records. Results Anti-DFS70 antibody prevalence by ELISA and LIA was 32.0% (63/197) and 19.8% (39/197), respectively. The agreement percentage between the two assays was 81.7%, with a kappa value of 0.53 (95% confidence interval: 0.40–0.66). Of the 69 DFS70+ samples (as per ELISA or LIA), the coexistence of other autoantibodies was found in 81.2% (56/69). Of the 128 DFS70- samples, 90.6% (116/128) revealed other autoantibodies. The three most frequent autoantibodies (except anti-DFS70) in 197 patients with AC-2 patterns were anti-SS-A/Ro-52 (30.5%, 60/197), anti-nucleosomes (27.4%, 54/197), and anti-histones (20.3%, 40/197). There was no significant difference in the prevalence of the other 22 autoantibodies between DFS70+ and DFS70− patients. The anti-DFS70 prevalence in the SARD group was 33.3% (50/150), and in the non-SARD was 40.4% (19/47) without significant difference. However, of the 69 DFS70+ patients, the isolated anti-DFS70 was found more frequently in the non-SARD group (36.8%, 7/19) than in the SARD group (12.0%, 6/50) (P = 0.0346). Conclusion The anti-DFS70 positive rate in AC-2 pattern samples is lower than a third, and the prevalence is affected by different detection assays. Along with the AC-2 pattern, just reporting the presence of anti-DFS70 is not valuable for SARD exclusion. Therefore, it is important to co-examine other autoantibodies, such as anti-SS-A, anti-nucleosomes, and anti-histones, to confirm the isolated anti-DFS70.

The significance of dense fine speckled pattern in antinuclear antibody-associated rheumatic disease and coexisting autoantibodies: A propensity score-matched cohort study.

To investigate the relationship between the prevalence of antinuclear antibody (ANA) -associated rheumatic diseases (AARD) and the presence of dense fine speckled (DFS) and homogeneous patterns in ANA tests. This retrospective study enrolled adult patients with either a DFS or homogeneous pattern in their ANA test. A mixed pattern was defined as the presence of more than one pattern reported in the test. The presence of anti-DFS70 antibodies and other common autoantibodies were detected using EUROLINE ANA Profile 23. A 1:2 propensity score matching was applied to control for demographic and other interfering factors. A total of 59 patients with a DFS pattern were enrolled and compared with a matched homogeneous group. The DFS group had a significantly lower prevalence of AARD (3.4% vs. 16.9%, p = .008) and the subgroup with anti-DFS70 antibodies showed an even lower prevalence (2% vs. 20%, p = .002). Among the 33 patients with monospecific anti-DFS70 antibodies, five had a mixed pattern, and all patients with common autoantibodies had an isolated DFS pattern. The findings of this study suggest that patients with a DFS pattern in their ANA test may have a lower prevalence of AARD compared with those with a homogeneous pattern. However, an isolated DFS pattern in ANA testing does not necessarily indicate the presence of monospecific anti-DFS70 antibodies or AARD. Confirmatory testing for the monospecific anti-DFS70 antibody is mandatory to exclude AARD.

A novel magnetic bead-based immunoprecipitation method for anti-dense fine speckled 70 antibodies

The indirect immunofluorescence assay (IIFA) on HEp-2 cells has been widely used for screening anti-nuclear antibodies (ANA) that are associated with systemic autoimmune rheumatic diseases (SARD). Sera containing ANA display multiple distinct fluorescence patterns on HEp-2 cells. Among them, a dense fine speckled (DFS) pattern caused by anti-DFS70 antibodies has been reported to have higher prevalence in healthy individuals than in patients with SARD. This DFS pattern is often difficult to distinguish amongst other SARD-associated ANA patterns, in particular a mixed homogeneous and speckled pattern. Furthermore, a strong DFS pattern can mask other SARD-associated patterns. Hence, we developed a novel immunoprecipitation method using magnetic beads to remove anti-DFS70 antibodies in serum prior to running IIFA. We also aimed to confirm the presence of anti-DFS70 and to uncover any SARD-associated ANA patterns masked by a strong DFS pattern. The sera used in our study were from 70 individuals who had routine ANA screen, of which 35 sera had an isolated DFS pattern with monospecific anti-DFS70 antibodies confirmed by a complementary assay, and 35 were control sera without a DFS pattern. An immunoprecipitation method using magnetic beads coated with recombinant human full length DFS70 protein was developed. The performance of this new method was evaluated in comparison to an immunoadsorption method using the same DFS70 protein. Our newly developed immunoprecipitation method demonstrated excellent sensitivity (91.4%) and specificity (100%) in confirming the DFS pattern associated with anti-DFS70 in sera. Additionally, our method was able to remove anti-DFS70 and uncover SARD-associated ANA patterns masked by a strong DFS pattern. It also showed a clearer background on IIFA than that of the immunoadsorption method. The novel magnetic bead-based immunoprecipitation method demonstrated satisfactory performance in removing anti-DFS70 without interfering with the detection of other antibodies. It can be easily integrated with IIFA to confirm anti-DFS70 associated DFS pattern. Additionally, it can simultaneously unmask other ANA patterns, which cannot be achieved by a conventional protocol that requires a complementary anti-DFS70 specific assay to be performed. Therefore, the novel method provides a more effective and accurate solution for ANA screening.

Differences in the Clinical Significance of Antinuclear Antibodies According to Titers and Patterns in Children.

This study aimed to evaluate the differences in the clinical significance of antinuclear antibody (ANA) according to their titers and patterns in the diagnosis of systemic autoimmune diseases (AiD) in pediatric patients. Of the 2442 children who had undergone an ANA test, 473 (19.4%) were positive for ANA, of whom 33 (7.0%) were diagnosed with significant AiD. The positive predictive value (PPV) for significant AiD was considerably high on application of an ANA titer of ≥1:640, and the PPV of a dense fine speckled (DFS) pattern was significantly lower compared with those of speckled and homogenous patterns. The diagnostic value of ANA positivity for AiD is limited, and the clinical significance of the DFS pattern is relatively lower compared with that of other patterns, such as homogenous and speckled patterns, in children. It is necessary to approach the significance of ANA in children individually depending on titers and patterns.

Significance of the immunofluorescence staining patterns and titres of the antinuclear antibody test in paediatric rheumatology setting.

Antinuclear antibody (ANA) is among the most frequently ordered tests in paediatric rheumatology setting. Diseases like systemic lupus erythematosus and Sjögren syndrome is closely related with a positive ANA and classified as ANA associated diseases. Besides, ANA test is ordered in patients with juvenile idiopathic arthritis (JIA) to assess the risk for uveitis and a positive ANA could be detected in children with nonrheumaticrheumatic conditions. In this study, we aimed to investigate frequency of positive ANA in paediatric rheumatology setting and the association of immunofluorescence staining patterns and titres of ANA with rheumatic diseases. : Immunofluorescence staining patterns, and titres of the ANA and diagnoses of children who tested for ANA between January 2016 and December 2021 were retrospectively analysed. Among 2477 patients with ANA tested, 28.1% had a positive ANA result. Among them, 39.2% had a diagnosis of a rheumatic disease. Most common rheumatic diagnosis was JIA (43.8%) and ANA associated diseases were observed in 24.5% of the patients with a rheumatic diagnosis. While ANA associated diseases had significantly more frequent homogenous staining, dense fine speckled pattern was significantly more common in children with nonrheumatic diagnoses. Despite ANA associated diseases was found to be significantly associated with higher titres, no difference was observed between patients with JIA and nonrheumatic conditions. Our study showed that the majority of children with a positive ANA test were not diagnosed with a rheumatic disease. While titres and patterns of ANA were found to be important in diagnosis of rheumatic diseases, ordering ANA test with solid indications might give improved probability of rheumatic diagnoses in children with a positive test.

Prevalence and clinical characteristics of the dense fine speckled pattern: Indirect immunofluorescence‐antinuclear antibody screening in the Chinese population

AbstractTo investigate the prevalence and clinical significance of the dense fine speckled (DFS) pattern in a large‐scale cohort of Chinese patients. Data on the antinuclear antibody (ANA) and extractable nuclear antigen (ENA) autoantibody obtained from 165 498 patients who attended Peking Union Medical College Hospital from January 2019 to December 2021 were retrospectively analysed. The prevalence of the DFS pattern was 1.14%, and it mainly appeared in young patients (≤24 years old). A higher positive rate of the DFS pattern was observed in patients with dermatosis (18.12%) and systemic autoimmune rheumatic diseases (SARDs) (13.53%). The DFS pattern titre was mostly low or medium (≤1:160). A higher titre was associated with an increased risk of SARDs (p &lt; .001), dermatosis (p = .015) and pulmonary disease (p = .016). In 37 patients with ENA autoantibody positivity, anti‐SSA antibody was the most common (2.55%). If the low titre (&lt;1:160) or the DFS pattern with negative ENA autoantibody were to be used as exclusion criteria for SARDs, the diagnosis would have been missed in 42 or 77 patients, respectively. The prevalence of the DFS pattern was low in ANA test samples and was more common in patients with dermatosis and SARDs, but the titre was usually higher in patients with SARDs. There was no evidence that the DFS pattern could be used as an exclusion criterion for SARDs diagnosis. The DFS pattern was associated with certain pathological states, which may inform the clinical significance of the DFS pattern.

Investigation of dense fine speckled pattern and anti-dense fine speckled 70 antibody by a single step assay

The indirect immunofluorescence (IIF) method is the gold standard for identifying anti-nuclear antibodies (ANAs). It is recommended that ANA, including the dense fine speckled (DFS) pattern, should be verified with a highly specific confirmatory test after a sensitive screening test. Although methods such as ELISA and LIA are often used to confirm the presence of anti-DFS70 antibodies, new IIF methods have been developed in recent years to prevent the difficulties in the recognition of the DFS pattern and to carry out the confirmatory test in a single step. In this study, we evaluated CytoBead (Generic Assays, Germany) test, which contained both HEp-2 cell substrate and beads coated with DFS70 antigen in one well, in comparison to the routine two-step test strategy. Five hundred forty-one samples were studied by conventional IIF assay, LIA, and CytoBead assay; 264 samples were studied by ELISA. The Bead component of the CytoBead test was found to be reliable as a confirmational test when compared with ELISA and LIA (total agreement values were 85.6% and 87.6%, respectively). The CytoBead ANA DFS70 might be a promising test in the future, allowing both screening and confirmation in a single step, saving time and being easier than two-step testing.

Transient positive antimitochondrial M2 in sera of patients with connective tissue diseases after intravenous immunoglobulin infusions

AbstractBackgroundAlthough antinuclear antibodies (ANAs), anti‐SSA and anti‐Ro52, are present in immunoglobulin preparations, it is unknown whether intravenous immunoglobulin (IVIG) therapy influences the testing of serum autoantibodies in patients with connective tissue diseases (CTDs). The present study aimed to investigate the dynamic change over time of serum ANA‐related autoantibodies in patients with CTDs receiving IVIG therapy.MethodsSerum ANA‐related autoantibodies were monitored in two patients with CTD before IVIG therapy and at different times after therapy. These autoantibodies were tested in different batches of immunoglobulin preparations from seven pharmaceutical companies.ResultsOne patient developed a new ANA pattern (cytoplasmic dense fine speckled pattern, AC‐19) just after IVIG therapy. Both patients developed de novo positivity for AMA‐M2 and anti‐SSA, but returned negative 1 month after IVIG therapy. The residual liquid in patients' immunoglobulin preparations showed positive ANAs with a high titer of AC‐19 (1:640), a low titer of the nuclear fine speckled pattern (AC‐4, 1:80), positive AMA‐M2, and positive anti‐SSA. ANA‐related autoantibodies were tested in 16 batches of immunoglobulin preparations and all had positive ANAs with two patterns: AC‐19 (1:640 or 1:320) and AC‐4 (1:80). AMA‐M2 and anti‐SSA were positive in 100% of the batches.ConclusionOur study highlights high‐titer AMA‐M2 autoantibodies in immunoglobulin preparations and suggests their transient transfer into a patient's circulation via IVIG therapy. To avoid incorrect clinical decisions based on postinfusion antibody titers, our data recommend retesting 1–2 months after high‐dose IVIG immunomodulatory treatment.

The choice of anti-LEDGF/DFS70 assay matters: a comparative study of six assays

Lens-epithelial derived growth factor (LEDGF/DFS70) autoantibodies result in the commonly observed dense fine speckled (DFS) pattern by anti-nuclear antibody (ANA) assay. However, there is no consensus approach for confirmation of this autoantibody specificity. To evaluate current approaches, we examined inter-assay agreement between six anti-LEDGF/DFS70 assays. A total of 395 consecutive sera samples from routine ANA diagnostics were obtained, tested by routine ANA, anti-ENA line immunoblot assay (LIA) and anti-dsDNA assay and with six anti-DFS/LEDGF assays: the EuroLine-LIA (Euro-LIA), Medical and Biological Laboratories ELISA (MBL-ELISA), Phadia-EliA (EliA), QUANTA Flash CLIA, EuroImmun ELISA (Euro-ELISA) and Immco-Diagnostics HEp-2 ELITE/DFS-Knockout (HEp-2KO). Of 395 sera, 108 tested positive by at least one assay. Despite general good concordance between all assays across the cohort (Gwet's AC1=0.89), within the target DFS-ANA pattern group inter-assay agreement was poor (AC1=0.59). Euro-LIA, CLIA and MBL-ELISA assays were most concordant, but CLIA and Euro-LIA were also most likely to identify discordant positive results. EliA and Euro-ELISA had poorer agreement, which could be attributable to ill-matched cut-offs between assays. HEp-2KO was frequently discordant with all other assays tested. Euro-LIA, CLIA and MBL-ELISA were most concordant at manufacturer's specifications and are suited for use in clinical laboratories. Modified assay thresholds are required to ensure comparative results for Euro-ELISA and EliA. HEp-2KO assay is frequently discordant with all other assays, making it less suited for routine diagnostics. The study highlights the importance of considering inter-assay variability when developing a diagnostic strategy for anti-LEDGF/DFS70 autoantibodies in clinical laboratories.

Frequency of ANA/DFS70 autoantibodies in Colombian patients with undifferentiated connective tissue disease.

The objective was to describe the clinical characteristics and the frequency of the ANA/DFS70 autoantibodies in patients affected by undifferentiated connective tissue disease (UCTD) in a tertiary hospital in Colombia. This descriptive cross-sectional study enrolled patients who fulfilled the classification criteria for UCTD. ANAHEp- 2 test and the modified assay for ANA/DFS70 autoantibodies were performed through the indirect immunofluorescence technique. Erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, and the antibodies to anti-extractable nuclear antigens, DNA, phospholipids (IgG, IgM, IgA), and cyclic citrullinated peptide were also evaluated. Fifty-three patients were studied; 42/53 (79%) tested positive for ANA and 5/42 (11.9%) for ANA/DFS70 antibodies with a dense fine speckled fluorescent pattern (AC-2) in ANA HEp-2 test that was confirmed by a modified HEp-2-DFS70 assay. Patients had arthralgia (87%, n=47), non-erosive arthritis (66%, n=34), xerostomia (64%, n=34), xerophthalmia (42%, n=22), and Raynaud's phenomenon (17%, n=9). Arthralgia, xerophthalmia, xeroderma, and absence of disease evolution to a specific disease over five years were more frequent in patients with a positive result for the anti-DFS70 antibodies. The ANA/DFS70 autoantibodies were more frequent in patients with UCTD compared to other rheumatic diseases for which they were initially evaluated. More studies are required to support the predictive role of this antibody to the absence of progression to a well-defined connective tissue disease.

VI Brazilian consensus guidelines for detection of anti-cell autoantibodies on HEp-2 cells

BackgroundThe VI Brazilian Consensus on Autoantibodies against HEp-2 cells for determination of autoantibodies against cellular constituents on HEp-2 cells was held on September, 2019, in Fortaleza (CE, Brazil). The guidelines in this edition were formulated by the group of Brazilian experts discussing the classification of complex patterns, the classification of the nuclear discrete dots (few and multiple), the identification of the discrete fine speckled pattern (AC-4a) and improvements on the ANA report.MainbodySixteen Brazilian researchers and experts from universities and clinical laboratories representing the various geographical regions of Brazil participated in the meeting. Four main topics were discussed: (1) How to classify patterns with fluorescence in more than one cell compartment considering three relevant categoris: composite patterns, mixed patterns and multiple patterns; (2) The splitting of the discrete nuclear dots pattern into the multiple discrete nuclear dots (AC-6) and few discrete nuclear dots (AC-7) patterns, respectively; (3) Inclusion of a novel nuclear pattern characterized by discrete fine speckled pattern highly associated with antibodies to SS-A/Ro60, classified as AC-4a. In addition, adjustments on the Brazilian Consensus nomenclature were implemented aiming to harmonize the designation of some patterns with the International Consensus on ANA Patterns (ICAP). Furthermore, the designations of the PCNA-like pattern (AC-13), CENP-F-like pattern (AC-14) and Topo I-like pattern (AC-29) were adjusted in accordance to ICAP. Finally, there was a recommendation for adjustment in the test report in order to address the status of nuclear envelope staining. For all topics, the aim was to establish specific guidelines for laboratories and clinicians. All recommendations were based on consensus among participants. All recommendations from the V Consensus were maintained and there was relevant progress in the BCA/HEp-2 guidelines and further harmonization with ICAP.ConclusionThe VI BCA/HEp-2 edition was successful in establishing important recommendations regarding the classification of complex patterns, in supporting the identification of a novel pattern within the AC-4 group and in the harmonization process with the ICAP terminology.

The clinical characteristics of nuclear dense fine speckled pattern in 95 289 patients

To investigate the distribution and clinical significance of nuclear dense fine speckled (DFS) pattern in various diseases. A total of 95 289 patients who received DFS tests at Peking Union Medical College Hospital from January 2019 to December 2020 were included in this study. The results of indirect immunofluorescence assay (IIF) for detection of antinuclear antibody (ANA) were evaluated. The positive rates of ANA and DFS were 39.60% (37 733/95 289) and 1.19% (1 139/95 289) respectively. The positive rate of DFS in ANA-positive patients was 3.02% (1 139/37 733). DFS and ANA positivity were significantly different among different age groups rather than gender. The positivity rate of DFS reached the peak (55.57%, 633/1 139) in young patients between 21-40 years, while positive ANA with negative DFS was mainly observed in patients between 41-60 years (37.26%, 13 636/36 594). Additionally, single ANA-positivity were mainly detected in rheumatology department (59.23%, 18 402/31 066), whereas positive DFS was more common in obstetrics and gynecology department (3.08%, 49/1 593). There were 82.88% (944/1 139) patients with positive DFS diagnosed with non-autoimmune disease (non-AID), and 19.49%(222/1 139) with dermatosis. Positive DFS with higher titer (≥1∶320) was detected more frequently in autoimmune disease (AID) patients (5.13%, 10/195) than in non-AID patients (1.69%, 16/944) (P<0.05). The DFS pattern is rare in ANA positive patients, which is mainly observed in women between 21-49 years. High titer of DFS is prevalent in AID patients, but positive DFS is detected more in non-AID patients, especially those with dermatosis.

The Prevalence and Clinical Relevance of the DFS Immunofluorescence Staining Pattern in a Large ANA-Positive Cohort.

BackgroundAlthough the dense fine speckled (DFS) immunofluorescence staining pattern has been studied by various researchers in recent years, its clinical associations remain unspecified. Thus, we performed a retrospective study in a non-selective population to explore the prevalence of this enigmatic antinuclear antibody (ANA) pattern and to determine its possible clinical associations with any identifiable pathology.MethodsWe retrieved the results of ANA testing ordered by various departments in 2019 to study the prevalence of DFS pattern. Demographic characteristics and clinical features of these participants were also collected from the electronic medical record system. Correlation analysis was made to study its clinical associations and a p-value < 0.05 was considered statistically significant.ResultsThe prevalence of ANA positivity was 37.4% among 72,204 serum samples of which the median age was 44 (interquartile range: 31, 56) years old and 68.0% were women. The prevalence of the DFS staining pattern was 1.1% in the total population and accounted for 3.1% in the ANA-positive population. There were 97.6% of these cases displaying the DFS pattern with a low titer of ANA (≤1:320; starting serum dilution: 1:100). We found that this pattern correlated with several pathological conditions, such as skin disorders (25.1%), alopecia (4.6%), and obstetric complications (6.6%).ConclusionThe presence of the DFS immunofluorescence staining pattern may accompany several pathological conditions and may be a signal of localized inflammation within certain organs or tissues, especially the skin.