Anticardiolipin antibodies during hormone replacement therapy in healthy postmenopausal women

The aim of the study was to investigate IgG and IgM anticardiolipin (aCL) antibodies in the course of hormone replacement therapy (HRT).

Thirty clinically healthy postmenopausal women with no history of previous thrombotic events or autoimmune disease were divided in two groups: control group (n = 12, mean age 52.9 +/- 4.5 years, and 6.2 +/- 3.6 years duration of amenorrhea) and a second group (n = 18, mean age 53.6 +/- 3.5 years, and 5.7+/- 4.5 years of amenorrhea) who were allocated to HRT, containing 2 mg 17-beta estradiol plus 1mg norethisterone acetate daily for 6 months. ACL antibodies of IgG and IgM isotype were assessed using ELISA and the Kupperman menopausal index (KI) was calculated at baseline and after 3 and 6 months of treatment.

HRT had a beneficial effect on climacteric symptoms, evaluated by KI (baseline versus 3rd month and 3rd month versus 6th month, P < 0.001 ). The KI did not change in the control group. The values of IgG at the three studied periods did not change significantly and were 14.1 +/- 4.2, 13.1 +/- 4.9 and 13.4 +/- 3.7 in the HRT group and 12.7 +/- 3.1, 13.7 +/-1.8 and 13.1 +/- 3.8 GPL, respectively, in the control group. IgM aCL antibodies increased during HRT and were as follows: 7.7 +/- 4.8 at baseline, 12.9 +/- 5.6 at 3rd month and 9.3 +/- 3.2 MPL at 6th month. In the control group, IgM were 8.0 +/- 2.8; 7.9 +/- 2.3 and 7.1 +/- 2.3 MPL, respectively. The differences between the two groups were significant at the third and the 6th month (P < 0.01 and P < 0.05 ).

These data suggest that HRT is associated with elevation of IgM ACA in healthy postmenopausal women. As IgG aACA are considered more pathogenic, it seems unlikely that the early prothrombogenic effects of HRT can be assigned to ACA.