Impaired human ovarian follicular fluid complement function in hereditary angioedema.

We sought and detected functionally active complement in human ovarian follicular fluid obtained during the peri-ovulatory period. All the functional complement activities tested, including total haemolytic complement, classical pathway activity, alternative pathway activity and C1 inhibitor function were present with values within the normal serum range. Active complement in follicular fluid is relevant for the function of the enzymatic multifactorial mechanism of ovulation. The presence in hereditary angioedema patients of both complement (C1 inhibitor deficiency and chronically consumed complement) and ovarian abnormalities (cystic ovaries), led us to study complement function in the follicular fluid of women of reproductive age affected with hereditary angioedema. In contrast to healthy women, hereditary angioedema patients showed dramatically reduced classical pathway activity and undetectable functional and antigenic C1 inhibitor. C4 was very low, while C3 and B were slightly reduced or within the normal serum range. This complement profile was also detected in patients' sera. Since hereditary angioedema patients often show cystic ovaries (polycystic or multifollicular), the presence of multifollicular ovaries in the two patients studied, along with complement dysfunction, may be relevant. These findings, as well as the normalisation of the ovaries found by us in hereditary angioedema patients and in the patients reported here who were undergoing danazol treatment, and the increase in C1 inhibitor and the improvement of clinical symptoms, suggest a further link between complement and ovarian function.