OBJECTIVES: This study aimed to determine the frequency and antibody titers of nuclear dense fine and cytoplasmic patterns with possible clinical correlation. METHODS: From 2007 to 2009, the results of 2,788 autoantibody serological tests were assessed by indirect immunofluorescence (IIF) at LAC-HUSM/UFSM, using as substrate HEp-2. RESULTS: Among the analyzed samples, 1,998 of them were negative for autoantibodies. Among the positive samples (n = 790), we found 57 (7.2%) showing reactivity pattern described as dense fine speckled (DFS) (3.8%), or cytoplasmic (Cit) fluorescence (3.4%). In samples with standard DFS (n = 29), nine had titers of 1/160, and only one patient had autoimmune disease (AID). Among patients with titers > 1/160, only one patient did not have AID. Among samples with standard Cit (n = 27), 20 had titers of 1/160, and only eight were not associated with AID. The other seven patients with titers > 1/160 reported AID. CONCLUSION: The results confirm the value of 1/160 as the best cut-off point for defining AID presence, for any of the fluorescence assessed patterns. However, attention should be given to lower titers, especially for Cit IIF, since only 40% did not report the presence of AID
antibodies; fluorescent antibody technique; autoimmunity
