The topic of the Matsumi Ladies Clinic Mita English blog in December is our presentation at the 37th Annual Meeting of the Japanese Society for Immunology of Reproduction.

The summary of our presentation is described as below.

 

[Title]
Correlation between antiphospholipid antibodies and the coagulation-fibrinolysis system in women with a history of miscarriage – comparison between conventional antiphospholipid antibodies and neo-self antibodies.

 

[Objective]
The clinical diagnostic criteria for antiphospholipid antibody syndrome (APS) include thrombosis and obstetric complications; alterations in the coagulation-fibrinolysis system due to pathogenic autoantibodies have been described as a common background for the clinical presentation of APS.

Recently, autoantibodies against β2-glycoprotein I (β2GPI) in complex with HLA class II molecules (β2GPI/HLA-DR) (neo-self antibodies) have been reported to be a novel autoantibody associated with APS.

The present study investigated the relationship between conventional antiphospholipid antibodies and neo-self antibodies and coagulation/fibrinolysis markers in women with a history of miscarriage.

 

[Methods]
Serum antibody titers of conventional antiphospholipid antibodies (anti-cardiolipin IgG/IgM, anti-β2GPI and lupus anticoagulant) and neo-self antibodies were measured in 58 women with a history of miscarriage.

Coagulation and fibrinolysis status was assessed by TAT, AT3 and D-dimer, and APTT. In addition, the relationship with subsequent pregnancy outcome was investigated.

 

[Results]
Ten women were positive for conventional antiphospholipid antibodies and six were positive for neo-self antibodies, including one patient who was positive for both.

28 patients had elevated plasma TAT levels and none of them showed APTT elongation.

The frequency of elevated plasma TAT levels was 80% (8/10) in the conventional antiphospholipid antibody-positive group and 83% (5/6) in the neo-self antibody-positive group.

Those ratios were higher than the TAT positivity of 37% (16/43) in the antibodies-negative group.

During the observational period, clinical pregnancy was confirmed in 23 cases, including 16 with plasma TAT elevation.

Among them, three cases resulted in early miscarriage, two of which had a plasma TAT elevation, one of which was positive for neo-self-antibodies.

 

[Conclusion]
Both the traditional antiphospholipid antibody-positive group and the neo-self antibody-positive group had a high frequency of plasma TAT elevation.

Alteration in coagulation/fibrinolytic system could be shared as the pathogenic background between the two groups and is possibly involved in the incidence of miscarriage.

When analyzing cases excluding TAT unmeasured cases, the plasama TAT concentration was elevated in 100% of neoself antibody-positive cases, and there were significantly more TAT-positive cases than negative cases (45%) (Chi-square test p= 0.03)

When the cases excluding those who had not measured plasama TAT concentrations were analyzed, TAT concentrations increased in 75% of conventional antiphospholipid antibody-positive patients, and no significant change was observed compared to negative cases (50%) (p=0.19).