title: Autoantibodies to lens epithelium-derived growth factor/transcription co-activator P75 (LEDGF/P75) in children with chronic nonspecific complaints and with positive antinuclear antibodies.
abstract: Autoimmune fatigue syndrome (AIFS) is characterized by chronic nonspecific complaints, consistently positive antinuclear antibodies (ANA), and lack of alternate medical explanations. A newly recognized antibody, named anti-Sa, was detected in approximately 40% of the patients by Western blot (WB) using HeLa extract. Some patients with AIFS later develop chronic fatigue syndrome (CFS), and most of them are positive for anti-Sa. On the other hand, Muro et al. reported anti-DFS70 in patients with CFS. Anti-Sa and anti-DFS70 were turned out to be same specificities by exchanging studies of blind sera. The target antigen of anti-DFS70 was identified as lens epithelium derived growth factor/transcription co-activator p75 (LEDGF/p75). The objectives of this study are to confirm whether the target antigen of anti-Sa is also LEDGF/p75, and to develop ELISA system by using recombinant protein. Recombinant protein of LEDGF/p75 was purchased from Protein One (Bethesda, MD, USA). We developed an ELISA system to detect anti-LEDGF/p75 by coating this recombinant protein. 226 sera of AIFS patients (including 36 CFS patients) were applied to this ELISA assay and Western immunoblot, and it was revealed that anti-Sa-positive sera defined by WB and sera positive for anti-LEDGF/p75 on ELISA were identical. Moreover, reactivities of anti-Sa on WB were inhibited by pre-incubating with recombinant LEDGF/p75, and eluted antibodies from the nitrocellulose membrane could react on the ELISA. These results confirm that the Sa antigen is LEDGF/p75. The ELISA assay using recombinant LEDGF/p75 could be a promising tool for measuring anti-Sa and consequently for diagnosing CFS.
authors: Department of Pediatrics, Nippon Medical School, Bunkyo City, Tokyo, Japan.
authors: Natsuko
authors: N
authors: Kuwabara
authors: Yasuhiko
authors: Y
authors: Itoh
authors: Tohru
authors: T
authors: Igarshi
authors: Yoshitaka
authors: Y
authors: Fukunaga
mesh_terms: D000974:Antibodies, Antinuclear / Q000097:blood* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology; D001327:Autoimmune Diseases / Q000175:diagnosis*; D015153:Blotting, Western; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis*; D006367:HeLa Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D036341:Intercellular Signaling Peptides and Proteins; D011994:Recombinant Proteins; C119380:lens epithelium-derived growth factor