Clinical significance of antinuclear antibodies associated with the nuclear dense fine speckled immunofluorescence pattern in autoimmune disease

Abstract

Objective To explore the prevalence of the nuclear dense fine speckled (DFS) immunofluorescence pattern in routine antinuclear antibodies (ANA) testing and its significance in patients with autoimmune diseases (AID). Methods The ANA in 13 728 specimens were measured by indirect immunofluorescence (IIF) using HEp–2 cell slides from department of clinical laboratory, wenling hospital from 2011 to 2014. The frequencies, clinical manifestations and laboratory features of DFS positivity were restrospectively analyzed in patients with AID, using χ2 test. Results ANA was positive in 20.56%(2 822/13 728) of the total patients, and the frequency of DFS pattern was observed in 1.81%(248/13 728) of the total patients and in 8.79%(248/2 822) of the patients with ANA positivity. In different age groups (≤20 years old, 21–49 years old and ≥50 years old), there were statistical significance of DFS pattern positive rate (male: χ2=18.17, P<0.01; female: χ2=1 500.00, P<0.01). And the highest frequency of ANA positivity was observed in patients from department of rheumatology (30.07%). The frequency of DFS pattern was higher in the departments of infection (32.58%), dermatology (21.76%), neurology (18.58%) and nephrology (6.73%) among the patients with ANA positivity (χ2=123.00, P<0.01). Amony the 248 cases with DFS pattern positivity.41 cases were AID (16.53%) and 207 cases were non– autoimmune diseases (83.47%). In AID group 13 cases were autoimmune thyroiditis (31.71%), 12 cases were rheumatoid arthritis (29.27%), 4 cases were autoimmune liver disease (9.76%), 4 cases were undifferentiated connective tissue disease (9.76%), 3 cases were ankylosing spondylitis (7.32%), 2 cases were Sjogren's disease (4.88%), 2 cases were inflammatory bowel disease (4.88%) and 1 case was systemic lupus erythematosus (2.44%). The titers of DFS in patients with AID were predominantly above 1∶320 and less than 1∶100 in non–AID. AID patients with DFS pattern positivity have different clinical manifestations and laboratory features. Howerer, antinuclear antibodies (ANAs) in 15 specific auto–antibodies were all negative. Conclusions The DFS pattern is a common pattern in ANA positivity patients and it mainly exists in non–AID patients. Further more, it is suggested that patients with DFS pattern identified by IIF should then be tested for anti–DFS70 antibodies with a specific immunoassay. (Chin J Lab Med, 2015, 38: 173–177) Key words: Autoimmune disease; Antibodies, antinuclear; Fluorescent antibody technique, indirect