Sexual activity modulates shifts in TH1 TH2 cytokine profile across the menstrual cycle An observational study

Sexually active women had significantly higher luteal- phase P-E2 ratios and TH2-like cytokine profiles (interferon-g < interleukin-4) than sexually abstinent women. Authors:
Tierney Kyle Lorenz, Ph.D., Julia R. Heiman, Ph.D., Gregory E. Demas, Ph.D.

Volume 104, Issue 6, Pages 1513-1521


To investigate if sexual activity moderated menstrual cycle–related shifts in cytokines associated with T-helper type 1 (TH1) cells (e.g., interferon [IFN] γ) and T-helper type 2 (TH2) cells (e.g., interleukin [IL] 4). Immune activity shifts across the menstrual cycle, with higher follicular-phase TH1-cell activity but higher luteal-phase TH2-cell activity. Little is known about how social behaviors alter TH1-TH2 ratios, despite evidence that psychosocial factors can influence immunity. Of particular interest is how sexual activity influences immune responses that may support conception, such as the TH1-TH2 balance.

Participants provided saliva samples at four time points (menstrual, follicular, ovulatory, and luteal phases), which were assayed by means of ELISA.

Academic laboratory.

Thirty healthy premenopausal women (16 sexually abstinent, 14 sexually active) not taking hormonal or immunoactive medications.


Main Outcome Measure(s):
Salivary E2, P, IFN-γ, and IL-4.

Sexually active, but not abstinent, women were significantly more likely to express TH2-like cytokine ratios (IFN-γ < IL-4) in the luteal phase than in other phases. Similarly, sexually active women had significantly higher P, and higher P-E2 ratios, in the luteal phase than did abstinent women. The P-E2 ratio mediated menstrual variations in cytokine ratios in sexually active women. Conclusion(s):
These results support the hypothesis that shifts in immune response across the menstrual cycle may reflect tradeoffs between reproduction and immunity. These findings point to the need for further research on the interaction between sexual behavior, the menstrual cycle, and immune response.

  • Shvetha Zarek

    Given that the participants were in long-term monogamous relationships, did the authors detect any differences in Th1/Th2 ratio based on the length of the relationship? Understandably, a larger study may be needed to answer this question. Interesting article!

  • Jason M. Franasiak

    An interesting study investigating the Th2-Th1 ratios. It will be of interest to see how this might be impacted at the level of the reproductive tract, perhaps via cervical swabs throughout the menstrual cycle.

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