Annexin A5 polymorphism (-1C-->T) and the presence of anti-annexin A5 antibodies in the antiphospholipid syndrome.
BACKGROUND
Annexin A5 is thought to have a role in the pathophysiology of the antiphospholipid syndrome (APS)-a syndrome characterised by recurrent thrombosis and pregnancy morbidity.


OBJECTIVE
To investigate whether anti-annexin A5 immunoglobulin (Ig)M or IgG antibodies, or the -1C-->T polymorphism of annexin A5, is a risk factor for thrombosis or miscarriage, and whether the -1C-->T polymorphism is correlated with APS.


METHODS
A cohort study was carried out with a population of 198 patients with primary APS, systemic lupus erythematosus or lupus-like disease. For the detection of anti-annexin A5 antibodies and the measurement of annexin A5 plasma levels, ELISA-type methods were used. The annexin A5 -1C-->T mutation was detected by restriction fragment length polymorphism.


RESULTS
71 patients were positive for annexin A5 IgM or IgG antibodies, of whom 53 patients were positive for anti-annexin A5 IgG antibodies and 27 of 198 patients were positive for anti-annexin A5 IgM antibodies. The prevalence of IgM or IgG anti-annexin A5 antibodies was not significantly associated with thrombosis or miscarriage on multivariate analysis. The prevalence of the -1C-->T mutation in the annexin A5 gene (46/198 patients) was significantly associated with miscarriage (odds ratio 2.7, 95% confidence interval 1.1 to 6.7, independent risk factor).


CONCLUSIONS
The detection of anti-annexin A5 antibodies does not seem relevant for estimating the risk for thrombosis or miscarriage in APS. The -1C-->T mutation was an independent risk factor for miscarriage, which is independent of APS.
de Laat
B
B
Department of Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Derksen
R H W M
RH
Mackie
I J
IJ
Roest
M
M
Schoormans
S
S
Woodhams
B J
BJ
de Groot
P G
PG
van Heerde
W L
WL
D000022:Abortion, Spontaneous / Q000235:genetics / Q000276:immunology; D000328:Adult; D017304:Annexin A5 / Q000097:blood / Q000235:genetics* / Q000276:immunology; D016736:Antiphospholipid Syndrome / Q000097:blood / Q000235:genetics* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008180:Lupus Erythematosus, Systemic / Q000097:blood / Q000235:genetics / Q000276:immunology; D008297:Male; D011110:Polymorphism, Genetic; D011247:Pregnancy; D012307:Risk Factors; D013927:Thrombosis / Q000235:genetics / Q000276:immunology
D017304:Annexin A5; D001323:Autoantibodies; D007074:Immunoglobulin G; D007075:Immunoglobulin M