Antibodies to endometrial transferrin and alpha 2-Heremans Schmidt (HS) glycoprotein in patients with endometriosis.
OBJECTIVE
Identifying the endometrial antigens inciting autoimmunity is important in setting up an antibody assay for a non-invasive diagnosis and clinical monitoring of endometriosis.


METHODS
Two-dimensional gel electrophoresis of endometrial extracts, Western blot analysis, passive hemagglutination and enzyme-linked immunosorbent assay (ELISA), amino acid sequencing and molecular studies were done on chosen antigens. Forty-six women with endometriosis, 4 women with uterine leiomyomata, 4 with pelvic adhesions, 3 with repeat Cesarean sections (conditions that coexist with or predispose to endometriosis) and 46 controls participated.


RESULTS
Antigens with molecular weights (MW) of 64 kDa [isoelectric point (pI) of 3.5-4.0] and 72 kDa (pI of 4.5) bound to IgG in all patients with endometriosis, but not the controls. Amino acid sequencing of the proteins revealed that they had homology to alpha 2-Heremans Schmidt (HS) glycoprotein (MW: 64 kDa) and transferrin (MW: 72 kDa). Endometriosis patients had significant antibody levels to these two proteins (predictive value of 80-90%). The analysis of patients' endometrial RNA detected the message for alpha 2-HS glycoprotein and transferrin. Albumin (pI 5.5) and collagen (pI 3.5) failed to elicit antibody responses.


CONCLUSIONS
Patients with endometriosis have significant antibodies to endometrial transferrin and alpha 2-HS-glycoprotein. We can effectively use an antibody assay using these antigens for diagnosing endometriosis.
Pillai
S
S
Department of Obstetrics, Medical University of South Carolina, Charleston 29425, USA.
Zhou
G X
GX
Arnaud
P
P
Jiang
H
H
Butler
W J
WJ
Zhang
H
H
D000328:Adult; D000595:Amino Acid Sequence; D001202:Ascitic Fluid / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology*; D015551:Autoimmunity; D001798:Blood Proteins / Q000235:genetics / Q000276:immunology*; D015153:Blotting, Western; D003094:Collagen / Q000276:immunology; D018076:DNA, Complementary; D015180:Electrophoresis, Gel, Two-Dimensional; D004715:Endometriosis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015723:Gene Library; D006386:Hemagglutination Tests; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D017421:Sequence Analysis; D012709:Serum Albumin / Q000276:immunology; D014168:Transferrin / Q000235:genetics / Q000276:immunology*; D060749:alpha-2-HS-Glycoprotein
C556354:AHSG protein, human; D001323:Autoantibodies; D001324:Autoantigens; D001798:Blood Proteins; D018076:DNA, Complementary; D007074:Immunoglobulin G; D012333:RNA, Messenger; D012709:Serum Albumin; D014168:Transferrin; D060749:alpha-2-HS-Glycoprotein; D003094:Collagen