Optimized detection of circulating anti-nuclear envelope autoantibodies by immunofluorescence

We have explored the presence of ANEA in 33 sera from patients with established PBC using three different Hep2 commercial slides and home-made slides with HeLa and Hep2 cells fixed with methanol, ethanol, 1% or 4% formaldehyde.We observed that the IF pattern was related to the cell type used (Hep2 or HeLa), the manufacturer and the cell fixation scheme. When both cell lines were fixed with 1% formaldehyde, the intensity of the cytoplasmic staining was considerably decreased regardless to the serum sample, whereas the prevalence of cytoplasmic autoantibodies was significantly lowered, as compared to any of the Hep2 commercial slide and fixation used. In addition, the prevalence of ANEA was importantly increased in formaldehyde-fixed cells.Immunofluorescence using appropriately fixed cells represent an easy, no time-consuming and low cost technique for the routine screening of sera for ANEA. Detection of ANEA is shown to be more efficient using formaldehyde-fixed cells instead of commercially available Hep2 cells.Circulating antinuclear antibodies (ANA) is a diverse group of autoantibodies found in patients with systemic or organ specific autoimmune diseases and a variety of infections, but also in asymptomatic normal individuals, although in low titres. ANA screening helps establishing diagnosis in patients with clinical features suggestive of an autoimmune or connective tissue disorders, while excluding (at least partially) the possibility of an autoimmune disorder in patients with few or uncertain clinical findings. In addition, they assist in monitoring disease progression and activity. Nuclear envelope is a complex structure consisting of outer and inner nuclear membranes, nuclear pore complexes (NPC) and the nuclear lamina [1]. Autoantibodies against nuclear envelope proteins exhibit a characteristic rim-like/peripheral pattern in IF. In a number of diseases, such as chronic fatigue syndrome, primary biliary cirrhosis and lupus or lupus-like syndrome the detecti