Detection of anti-annexin IV and V antibodies in patients with antiphospholipid syndrome and systemic lupus erythematosus.
OBJECTIVE
Annexins (Anx) are a family of structurally related proteins that bind to phospholipids in a calcium dependent manner. It has been reported that antibodies to Anx V, which acts as an antithrombotic protein, are associated with thrombosis in systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS). Homology between the primary structures of Anx IV and Anx V is the highest among members of the Anx family. We investigated whether anti-Anx IV autoantibodies can be detected in the sera of patients with SLE and/or APS.


METHODS
Seventy-four patients with SLE/APS were divided into 3 groups: Group A, patients with SLE but no clinical or serological features of APS; Group B, patients with SLE having only serological signs of APS; and Group C, patients with clinical symptoms and serological signs of APS. Anx IV and Anx V were prepared by recombinant technique. Anti-Anx IV, Anx V, cardiolipin (CL), and CL beta2-glycoprotein I were detected by ELISA.


RESULTS
Anti-Anx IV was found in 15.4% of Group A, 20.0% of Group B, and 21.7% of Group C. Anti-Anx V was found in 3.8% of Group A, 28.0% of Group B, and 30.4% of Group C. Significant correlations were noted between anti-Anx IV titer and anti-Anx V titer (p<0.001), and between anti-Anx IV titer and aCL titer (p<0.01).


CONCLUSIONS
Anti-Anx IV and V antibodies were characterized in the sera of patients with SLE/APS. Significantly higher frequency of arterial or venous thrombosis was found in patients with anti-Anx V.
Satoh
A
A
Graduate School of Humanities and Sciences and Department of Chemistry, Ochanomizu University, Tokyo, Japan.
Suzuki
K
K
Takayama
E
E
Kojima
K
K
Hidaka
T
T
Kawakami
M
M
Matsumoto
I
I
Ohsuzu
F
F
D000293:Adolescent; D000328:Adult; D017314:Annexin A4 / Q000276:immunology*; D017304:Annexin A5 / Q000276:immunology*; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000276:immunology*; D001323:Autoantibodies / Q000032:analysis* / Q000097:blood; D001667:Binding, Competitive / Q000187:drug effects; D002308:Cardiolipins / Q000276:immunology; D005260:Female; D006023:Glycoproteins / Q000276:immunology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010718:Phosphatidylserines / Q000494:pharmacology; D053482:beta 2-Glycoprotein I
D017314:Annexin A4; D017304:Annexin A5; D001323:Autoantibodies; D002308:Cardiolipins; D006023:Glycoproteins; D010718:Phosphatidylserines; D053482:beta 2-Glycoprotein I