Immune studies in oral contraceptive users

Influence of low-dose oral contraception on peripheral blood lymphocyte subsets at particular phases of the hormonal cycle

OBJECTIVE

To investigate the effects of low-dose oral hormonal contraception on the immune system during certain phases of the hormonal cycle.

DESIGN

Prospective, nonrandomized, controlled study.

SETTING

Academic research setting.

PATIENT(S)

Women with regular menstrual cycle using hormonal oral contraception (OC; Cileste, 250 microg of norgestimat and 35 microg of ethinylestradiol, or Marvelon, 150 microg of desogestrel and 30 microg of ethinylestradiol) and women not using hormonal or other forms of contraception.

INTERVENTION(S)

Peripheral blood lymphocyte subsets were determined by flow cytometry on the first day of menstruation (day 1), in the follicular phase (day 8), midcycle (day 15), and in the luteal phase (day 22).

MAIN OUTCOME MEASURE(S)

Levels of lymphocyte subpopulations.

RESULT(S)

Women using OC had significantly higher levels of CD3+ CD8+ cells throughout their pill cycle compared to controls. Furthermore, women taking Cileste had lower levels of natural killer (NK) cells during their cycle and also women taking Marvelon but only from days 8-15. Within the pill cycle of Cileste we observed an increase in CD20+ and CD20+ CD5+ cells from days 1-8.

CONCLUSION(S)

Cytotoxic lymphocytes, which are responsible for first-line immune defense, and B cells, which are involved in autoimmune disorders, are affected by OC.

Humoral immunity in oral contraceptive users. II. In vitro immunoglobulin production

The worldwide acceptance of steroid-based oral contraception makes it imperative that the effect of these agents on the immune system is understood. Nevertheless, information regarding the effect of steroid-based oral contraception on humoral immunoregulation is limited. In this report the in vitro production of IgG and IgM is measured following stimulation with either the T-dependent activator pokeweed mitogen (PWM) or the T-independent activator fixed/killed Staphylococcus aureus Cowan I (StaCw). No significant differences are observed between the in vitro IgG or IgM levels following stimulation with PWM or StaCw for females taking steroid-based oral contraceptives and females not taking steroid-based oral contraceptives. We conclude that humoral immunoregulation is unaltered in steroid-based oral contraceptive users.

The classical and alternate pathways of complement in oral contraceptive users

Whole complement (CH50), C3, C4, the alternate pathway activity of complement (APH50) and factor B were measured in 159 women currently taking oral contraceptives and in 186 women who were not taking the pill. The mean levels of all components of the complement, except APH50, were found to be elevated in current users compared to non-users. The elevation in serum levels was seen in the first year after initiation of oral contraceptive use. Thereafter, levels changed little with duration of use. Among women who stopped using oral contraceptives, complement levels were similar to those of women who had never used the pill. Results appeared to be similar irrespective of the type of progestagen included in the oral contraceptive. These data provide support for the view that oral contraceptives have no adverse effect on the classical and the alternate pathways of complement.

Effect of early postpartum use of the contraceptive implants, NORPLANT, on the serum levels of immunoglobulins of the mothers and their breastfed infants

Ten breastfeeding women had the contraceptive implants NORPLANT inserted between days 30 and 39 postpartum. The immunoglobulins IgG, IgM and IgA were measured in the serum of the mothers and the infants before insertion and five months later. A control group of breastfeeding mothers who did not use any contraception or used local barrier methods were similarly studied. Although there were changes in the immunoglobulin levels with time in both mothers and infants, there were no group differences; this indicates that the use of NORPLANT does not influence these factors of humoral immunity.

Plasma alpha-feto protein levels and its relation to duration of oral contraceptive use

Plasma alpha-feto protein (AFP) levels were measured by radioimmunoassay in 73 women using oral contraceptive pills for varying durations of time. The levels were significantly higher at 6 months of pill use and tended to return to normal after 12 months. In none of the women was plasma AFP higher than 25 ng/ml which is considered to be indicative of liver damage.