| Popis: |
Background: Nucleardense fine speckled (DFS) patternon Hep-2 substrate with confirmed DFS70 reactivity, as the single ANA specificity, has been suggested as exclusion marker for systemic autoimmunerheumatic diseases (SARD). The aim was to asses:the frequencyof DFS pattern, the rate of DFS pattern with confirmed DFS70 reactivity, the association between DFS70 positivity and ANA titer. Materials and methods: We examined the resultsof ANA IIF in periodof 8.5 months. ANA IIF was performed using Hep-2 test system (Euroimmun, Luebeck, Germany). According to internal protocol, anti-DFS70 is performed only in the DFS pattern positive patients with requested ENA in whom ENA7 screen test is negative. ENA7 and anti-DFS70 was determined using Quanta Flash chemmiluminescenceimmunoassays on BIO-FLASH instrument (all INOVA Diagnostics, Inc., San Diego, CA, USA). Results: Positive ANA was found in 1734/4473 (38.7%) and DFS pattern in 296/1734 (17.1%) samples.Following internal protocol, anti- DFS70 reactivity was determined for 180/296 samples and confirmed in 55/180 (30, 5%) samples. Frequency of positive anti-DFS70 was compared for 4 ANA titer categories(1/160, 1/320, 1/640, >1/640). Significant difference was found (P = 0, 0009) with trend of rising frequency in paralel with rising ANA titer (12.8%, 24.6%, 38.1%, 52.6%, respectively).Low correlation was found between anti-DFS level and ANA titer (p= 0.295 (95%CI 0.155-0.423)P=0.0001). Conclusion: Anti-DFS70 reactivity was confirmed in 30.5% DFS pattern ssuggesting that the rest can be referred to pseudo-DFS pattern which seems to be more frequent. Our results confirmed the association of DFS70 reactivity with high ANA titer. |
