Relevância clínica e frequência de padrões citoplasmático e pontilhado fino denso observados em FAN-HEp-2

Andréia Martini Pazini, Juliana Fleck, Rosane Souza dos Santos, Sandra Trevisan Beck

This study aimed to determine the frequency and antibody titers of nuclear dense fine and cytoplasmic patterns with possible clinical correlation. 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. 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. 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.