Anti-DFS70 antibodies detected by immunoblot methods: A reliable tool to confirm the dense fine speckles ANA pattern.

Background: Autoantibodies to the DFS70 (dense fine speckles 70) protein have been identified among the antinuclear antibodies (ANA) in patients with various disorders. However, the ANA test in indirect immunofluorescence (IIF) is not a reliable method to identify anti-DFS70 antibodies. We undertook this study to evaluate the diagnostic performance of two new immunoblot methods for the detection of anti-DFS70 antibodies and to investigate whether their different DFS70 antigen composition could affect diagnostic accuracy in detecting anti-DFS70 antibodies.

Specific chemoluminescence and immunoasdorption tests for anti-DFS70 antibodies avoid false positive results by indirect immunofluorescence.

Objective: To evaluate two new diagnostic methods for the identification of anti-DFS70 antibodies in samples showing a DFS70-staining pattern by indirect immunofluorescence (IIF).

Methods: We studied 731 patients: 576 were collected consecutively among those that in the ANA test on HEp-2 cells had produced a DFS70 fluorescence pattern and 155 were a consecutive series of patients sent by referring physicians for routine ANA testing. As controls we studied 50 patients with autoimmune diseases and 120 patients with active infectious disease.

Automated antinuclear immunofluorescence antibody screening: a comparative study of six computer-aided diagnostic systems.

Background: Indirect immunofluorescence (IIF) plays an important role in immunological assays for detecting and measuring autoantibodies. However, the method is burdened by some unfavorable features: the need for expert morphologists, the subjectivity of interpretation, and a low degree of standardization and automation. Following the recent statement by the American College of Rheumatology that the IIF technique should be considered as the standard screening method for the detection of anti-nuclear antibodies (ANA), the biomedical industry has developed technological solutions which might significantly improve automation of the procedure, not only in the preparation of substrates and slides, but also in microscope reading.

Overcoming a "probable" diagnosis in antimitochondrial antibody negative primary biliary cirrhosis: study of 100 sera and review of the literature.

Serum anti-mitochondrial antibodies (AMA) are the serological hallmark of primary biliary cirrhosis (PBC), yet up to 15% of PBC sera are AMA negative at routine indirect immunofluorescence (IIF) while being referred to as "probable" cases. The diagnostic role of PBC-specific antinuclear antibodies (ANA) remains to be determined. We will report herein data on the accuracy of new laboratory tools for AMA and PBC-specific ANA in a large series of PBC sera that were AMA-negative at IIF.