The clinical spectrum of antinuclear antibodies associated with the nuclear dense fine speckled immunofluorescence pattern.
OBJECTIVE
Autoantibodies to lens epithelium-derived growth factor (LEDGF) depict a distinctive nuclear dense fine speckled (DFS) pattern in the indirect immunofluorescence antinuclear antibody assay (IIF-ANA). Definition of the clinical spectrum associated with anti-LEDGF antibodies has been evolving over the last decade. We investigated the frequency, clinical spectrum, and immunologic specificity of the DFS pattern in a general clinical laboratory routine. METHODS. All serum samples entered for IIF-ANA determination within a 2 year period were examined for the DFS pattern. Positive samples with consistent clinical information were studied further by IIF with isotype-specific conjugate and immunoblot analysis.


RESULTS
Among 13,641 ANA-positive samples, 5081 (37%) presented the DFS pattern. Within a 6 month nested period, there were 650 samples with DFS pattern, and consistent clinical data were available for 81 of these. DFS reactivity was mainly due to IgG. Most samples (86%) presented titer > or = 1/640. Eighty of the 81 DFS samples reacted with a 75 kDa band that comigrated with the band elicited by the standard anti-LEDGF serum. Antibodies that were affinity-purified from the 75 kDa band reproduced the DFS pattern on IIF-ANA. The clinical spectrum associated with DFS reactivity included autoimmune diseases (39%) and an array of nonautoimmune conditions (61%). Among the autoimmune patients, over half presented evidence of autoimmune thyroiditis.


CONCLUSIONS
Anti-LEDGF/p75 antibodies are a common finding among ANA-positive individuals with no evidence of rheumatic autoimmune disease, and should be regarded as a low specificity finding even when in moderate or high titer.
Dellavance
Alessandra
A
Fleury Research Institute, São Paulo, Brazil.
Viana
Vilma S T
VS
Leon
Elaine P
EP
Bonfa
Eloisa S D O
ES
Andrade
Luís E C
LE
Leser
Paulo G
PG
D048868:Adaptor Proteins, Signal Transducing / Q000276:immunology; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology* / Q000302:isolation & purification; D000918:Antibody Specificity; D006528:Carcinoma, Hepatocellular; D002467:Cell Nucleus / Q000276:immunology; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D006367:HeLa Cells; D006801:Humans; D008113:Liver Neoplasms; D012216:Rheumatic Diseases / Q000175:diagnosis* / Q000276:immunology*; D014157:Transcription Factors / Q000276:immunology
D048868:Adaptor Proteins, Signal Transducing; D019268:Antibodies, Antineutrophil Cytoplasmic; C504649:PSIP1 protein, human; D014157:Transcription Factors