Objective:To conduct consistency analysis of antinuclear antibody (ANA) anti-cell type 2 (AC-2) fluorescence pattern based on HEp-2 cells and monkey liver matrix, and to investigate the clinical significance of the AC-2 and anti-dense fine speckled 70 (DFS70) antibody.Methods:This study is a cross-sectional study. Retrospective analysis of the results of 33 921 ANA tests detected by indirect immunofluorescence assay (IIFA) from January 2024 to December 2024 in Shengjing Hospital of China Medical University. A total of 457 patients with AC-2 positive were taken from the cohort as the research objectives, then the positive rate of AC-2 in ANA among the 457 patients and its distribution in different diseases were counted. One hundred cases were selected from 457 AC-2 positive cases, whose AC-2 fluorescence pattern were analyzed using HEp-2 cells and HEp-2 cells combined with monkey liver matrix and the anti-DFS70 antibody was detected to help identifying the AC-2 fluorescence pattern. Finally, the consistency of the two methods in identifying the AC-2 fluorescence pattern was compared and the clinical significance of the AC-2 and anti-DFS70 antibody was discussed. Spearman correlation analysis was used to compare the correlation between the reciprocals of ANA titer of AC-2 positive samples and the levels of anti-DFS70 antibody.Results:AC-2 positive cases accounted for 1.15% (457/33 921) and 3.64% (457/12 555) of the all cases and ANA positive cases, respectively. The positive rate of AC-2 in females (394/457) was higher than that in males (63/457), P<0.01. Totally 87.09% of the AC-2 positive patients aged 40 and below. Moreover, the most positive cases of AC-2 occured in female infertility, adverse pregnancy history, pregnancy status and patients with connective tissue disease or joint pain/arthritis, accounting for 57.33% of the total positive cases. AC-2 positive patients were mostly distributed in women with infertility, bad pregnancy history, pregnancy status, connective tissue disease or patients manifested with joint pain/arthritis, accounting for 57.33% (262/457) of the total positive cases.The consistency analysis of AC-2 fluorescence pattern based on HEp-2 cells and HEp-2 cells combined with monkey liver matrix showed that among 100 serum samples, 97 cases were unanimously determined to be AC-2 fluorescence pattern, suggesting that HEp-2 cells can identify most AC-2 fluorescent pattern.The other three cases were identified as AC-1 and AC-5, and these AC-2 miscible pattern could be identified by monkey liver matrix and DFS70 antibody. In addition, the positive rate of anti-DFS70 antibody was 92.78% (90/97) in AC-2 fluorescent pattern, and the titer of ANA was positively correlated with the concentration of anti-DFS70 antibody in 62 cases with single positive anti-DFS70 antibody ( r=0.441, P<0.05). Among 62 cases of single positive anti-DFS70 antibody, 5 patients with connective tissue disease and 57 patients with non-autoimmune diseases; among the 25 cases of positive DFS70 antibody combined with non-positive ANA spectrum antibody, 4 cases were pregnant, and 16 cases had infertility or bad pregnancy history. All of them were combined with anti-thyroid globulin or thyroid peroxidase antibody positive, lupus anticoagulant positive, phospholipid antibody and herpes virus, rubella virus or cytomegalovirus antibody positive. Two cases were arthritis patients with positive anti-cyclic citrulline colypeptide antibody. One patient was Hashimoto′s thyroid, and 1 case was antiphospholipid syndrome. Three autoimmune diseased patients with positive DFS70 antibody were combined with positive ANA spectrum antibody, which were anti-Sjogren′s syndrome A antigen, polymyositis-scleroderma antigen antibody. Conclusion:Most AC-2 fluorescent pattern can be identified by HEp-2 cells, monkey liver matrix and anti-DFS70 antibody are helpful to identify AC-2, AC-2 fluorescent pattern and DFS70 antibodies can be positive alone or combined with ANA spectrum antibodies and other non-ANA spectrum antibodies in different diseases, which account for a high proportion of female infertility patients, patients with bad pregnancy history and pregnancy status.

Objective:To conduct consistency analysis of antinuclear antibody (ANA) anti-cell type 2 (AC-2) fluorescence pattern based on HEp-2 cells and monkey liver matrix, and to investigate the clinical significance of the AC-2 and anti-dense fine speckled 70 (DFS70) antibody.Methods:This study is a cross-sectional study. Retrospective analysis of the results of 33 921 ANA tests detected by indirect immunofluorescence assay (IIFA) from January 2024 to December 2024 in Shengjing Hospital of China Medical University. A total of 457 patients with AC-2 positive were taken from the cohort as the research objectives, then the positive rate of AC-2 in ANA among the 457 patients and its distribution in different diseases were counted. One hundred cases were selected from 457 AC-2 positive cases, whose AC-2 fluorescence pattern were analyzed using HEp-2 cells and HEp-2 cells combined with monkey liver matrix and the anti-DFS70 antibody was detected to help identifying the AC-2 fluorescence pattern. Finally, the consistency of the two methods in identifying the AC-2 fluorescence pattern was compared and the clinical significance of the AC-2 and anti-DFS70 antibody was discussed. Spearman correlation analysis was used to compare the correlation between the reciprocals of ANA titer of AC-2 positive samples and the levels of anti-DFS70 antibody.Results:AC-2 positive cases accounted for 1.15% (457/33 921) and 3.64% (457/12 555) of the all cases and ANA positive cases, respectively. The positive rate of AC-2 in females (394/457) was higher than that in males (63/457), P<0.01. Totally 87.09% of the AC-2 positive patients aged 40 and below. Moreover, the most positive cases of AC-2 occured in female infertility, adverse pregnancy history, pregnancy status and patients with connective tissue disease or joint pain/arthritis, accounting for 57.33% of the total positive cases. AC-2 positive patients were mostly distributed in women with infertility, bad pregnancy history, pregnancy status, connective tissue disease or patients manifested with joint pain/arthritis, accounting for 57.33% (262/457) of the total positive cases.The consistency analysis of AC-2 fluorescence pattern based on HEp-2 cells and HEp-2 cells combined with monkey liver matrix showed that among 100 serum samples, 97 cases were unanimously determined to be AC-2 fluorescence pattern, suggesting that HEp-2 cells can identify most AC-2 fluorescent pattern.The other three cases were identified as AC-1 and AC-5, and these AC-2 miscible pattern could be identified by monkey liver matrix and DFS70 antibody. In addition, the positive rate of anti-DFS70 antibody was 92.78% (90/97) in AC-2 fluorescent pattern, and the titer of ANA was positively correlated with the concentration of anti-DFS70 antibody in 62 cases with single positive anti-DFS70 antibody ( r=0.441, P<0.05). Among 62 cases of single positive anti-DFS70 antibody, 5 patients with connective tissue disease and 57 patients with non-autoimmune diseases; among the 25 cases of positive DFS70 antibody combined with non-positive ANA spectrum antibody, 4 cases were pregnant, and 16 cases had infertility or bad pregnancy history. All of them were combined with anti-thyroid globulin or thyroid peroxidase antibody positive, lupus anticoagulant positive, phospholipid antibody and herpes virus, rubella virus or cytomegalovirus antibody positive. Two cases were arthritis patients with positive anti-cyclic citrulline colypeptide antibody. One patient was Hashimoto′s thyroid, and 1 case was antiphospholipid syndrome. Three autoimmune diseased patients with positive DFS70 antibody were combined with positive ANA spectrum antibody, which were anti-Sjogren′s syndrome A antigen, polymyositis-scleroderma antigen antibody. Conclusion:Most AC-2 fluorescent pattern can be identified by HEp-2 cells, monkey liver matrix and anti-DFS70 antibody are helpful to identify AC-2, AC-2 fluorescent pattern and DFS70 antibodies can be positive alone or combined with ANA spectrum antibodies and other non-ANA spectrum antibodies in different diseases, which account for a high proportion of female infertility patients, patients with bad pregnancy history and pregnancy status.