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Updated: Jan 17, 2026
Simultaneous Distinction of Monospecific and Mixed DFS70 Patterns During ANA Screening with a Novel HEp-2 ELITE/DFS70 Knockout Substrate
Published on: January 17, 2018
Staining and serological characteristics of the AC-30 pattern in HEp-2 IIFA: a comparative study with AC-2 pattern
Chuiwen Deng1,2,3,4, Ningxin Li1,2,3,4, Ruxi Hu5
1Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China.
Objectives:
To investigate the staining and serological characteristics of AC-30 pattern.
Methods:
A total of 184 participants were recruited from patients who underwent routine antinuclear antibody testing between 2022 and 2023 at Peking Union Medical College Hospital. Cohort 1 (n=47) showed the AC-30 pattern on HEp-2 indirect immunofluorescence assay, and cohort 2 (n=137) showed AC-2 pattern as control. Anti-DFS70 antibody detection and DFS70 antigen adsorption assays were conducted. Pattern simulation assays were performed by combining serum samples exhibiting classic AC-2 pattern with other common HEp-2 IIFA patterns.
Results:
Anti-DFS70 antibodies were detected in 97 % of patients in cohort one and in all patients in cohort 2. The titers of the IIFA pattern showed a weak correlation with anti-DFS70 antibody levels in cohort 1 (r=0.35, p=0.0331). In DFS70 antigen adsorption assays, a higher proportion of homogeneous nuclear staining was observed in cohort 1 (79 %) than in cohort 2 (62 %) (p=0.037). Simulated samples mixed classic AC-2 with homogeneous pattern resembled those of AC-30 pattern in both interphase and mitotic cells. Especially, the staining characteristics of AC-2 became increasingly indistinct when mixed with higher-titer homogeneous patterns. Among samples exhibiting homogeneous patterns post-DFS70 immunoadsorption, non-autoimmune conditions were more common in cohort one than cohort two.
Conclusions:
The presence of relatively lower anti-DFS70 antibodies levels or coexisting high-titer homogeneous patterns may contribute to the development of the AC-30 pattern rather than AC-2. This finding needs to be further confirmed in larger-scale studies.
Insights
The AC-30 pattern in antinuclear antibody testing may result from lower anti-DFS70 antibody levels or coexisting homogeneous patterns, distinguishing it from the AC-2 pattern. Further research is needed to confirm these findings in larger patient cohorts.
Area of Science:
- Immunology
- Clinical Chemistry
- Autoimmunity
Background:
- Antinuclear antibody (ANA) testing is crucial for diagnosing autoimmune diseases.
- The HEp-2 indirect immunofluorescence assay (IIFA) is a standard method for ANA detection, yielding various patterns.
- The AC-30 pattern's origin and relationship with other ANA patterns, particularly AC-2, require clarification.
Purpose of the Study:
- To investigate the distinct staining and serological characteristics of the AC-30 pattern.
- To differentiate the AC-30 pattern from the AC-2 pattern in ANA testing.
- To explore the role of anti-DFS70 antibodies and homogeneous patterns in AC-30 formation.
Main Methods:
- Recruited 184 patients undergoing routine ANA testing.
- Analyzed 47 patients with AC-30 pattern (Cohort 1) and 137 with AC-2 pattern (Cohort 2).
- Conducted anti-DFS70 antibody detection, DFS70 antigen adsorption assays, and pattern simulation studies.
Main Results:
- Anti-DFS70 antibodies were detected in 97% of Cohort 1 and 100% of Cohort 2.
- Simulated AC-30 patterns by mixing AC-2 with homogeneous patterns, especially at higher titers.
- Observed a higher prevalence of homogeneous nuclear staining post-DFS70 adsorption in Cohort 1 (79%) vs. Cohort 2 (62%).
- Found non-autoimmune conditions more common in Cohort 1 among samples with homogeneous patterns post-adsorption.
Conclusions:
- The AC-30 pattern may arise from lower anti-DFS70 antibody levels or concurrent high-titer homogeneous patterns, differentiating it from AC-2.
- These findings suggest a complex interplay of antibodies contributing to specific ANA IIFA patterns.
- Larger studies are warranted to validate these observations and their clinical implications.
