Serologic evaluations of women exposed to breast implants

There continues to be uncertainty whether women with silicone breast implants experience activation of their immune system and show increased prevalence of serologic markers of connective tissue diseases. We conducted laboratory tests in a large number of women with and without breast implants, and in diabetic patients with presumed silicone exposure via insulin syringes.

Subjects were chosen from women enrolled in the run-in phase of the Women's Health Study (WHS, a randomized trial testing aspirin and vitamin E in preventing cardiovascular disease and cancer), and included 298 women without breast implants, 298 women with breast implants, and 52 diabetic patients diagnosed before age 30. Comparison groups were matched on age, race, date of blood provided to the WHS, and randomization status. We compared the proportion with abnormal results in 16 serologic tests among the 3 groups of women, stratifying by the matching factors. We also tested for monoclonal immunoglobulins by electrophoresis.

For 14 of the 16 serologic tests, the proportions with abnormal results among the 3 groups of women were not significantly different. Of the remaining tests, C3 levels were decreased in 8 (2.7%) women without breast implants and 22 (7.4%) women with breast implants (p = 0.003). C4 levels were decreased in 31 (10.4%) women without breast implants and 48 (16.1%) women with breast implants (p = 0.03). Women without breast implants and diabetic patients did not differ significantly in the proportions having decreased C3 and C4 levels. Women with breast implants did not have higher frequency of monoclonal immunoglobulins detected by electrophoresis.

We found little evidence for activation of the immune system in women with breast implants. The clinical significance of isolated reductions in C3 and C4 levels, in the absence of other abnormalities such as elevated levels of antinuclear antibody, is unknown.