Identification of autoantibody against poly (ADP-ribose) polymerase (PARP) fragment as a serological marker in systemic lupus erythematosus.
OBJECTIVE
By utilizing serological analysis of a recombinant cDNA expression library (SEREX), we previously found that autoantibodies to poly (ADP-ribose) polymerase (PARP) are specifically present in the sera of patients with SLE. In this study, recombinant proteins of various domains of PARP were used to determine the PARP domain that is associated with SLE.


METHODS
We produced four recombinant PARP proteins, which contained various PARP domains, and then carried out enzyme linked immunosorbent assay (ELISA) using these recombinant proteins to identify domains useful for SLE diagnosis. The recombinant proteins used in this analysis were; ADPNF (amino acids 1-234), ET-L2 (amino acids 339-680), ET-L3 (amino acids 681-1014), and ADPCF (amino acids 300-1014).


RESULTS
ELISA with ADPNF or ET-L2 showed low sensitivity in the sera of patients with SLE (14.3% and 17.0% respectively), whereas ELISA with ET-L3 or ADPCF showed high sensitivity in the sera of patients with SLE (34.0% and 49.1%, respectively). Autoantibodies to ADPCF were not found in the sera of patients with rheumatoid arthritis (0/30), systemic sclerosis (0/30) or healthy donors (0/54) and were rarely found in polymyositis/dermatomyositis (1/30) and Sjogren syndrome (1/14). Autoantibodies to ADPCF were closely associated with the presence of an oral ulcer in SLE (P=0.03, by the chi-square test).


CONCLUSIONS
The high sensitivity and specificity shown by autoantibodies to ADPCF protein could be used as a valuable serologic maker for the diagnosis of SLE.
Jeoung
Dooil
D
Division of Life Sciences, Kangwon National University, Chuncheon 200-701, Republic of Korea.
Lim
Yoon
Y
Lee
Eun Bong
EB
Lee
Seongeun
S
Kim
Hae-Yeong
HY
Lee
Hansoo
H
Song
Yeong Wook
YW
D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D020134:Catalytic Domain; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis* / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism
D001323:Autoantibodies; D015415:Biomarkers; D010446:Peptide Fragments; D011994:Recombinant Proteins; D011065:Poly(ADP-ribose) Polymerases