Title : Evaluate the changes in SP-D levels in plasma during different phases of the menstrual cycle recruited from the Well- Adult Surfactant Protein Study (WASP)
Abstract:
Background: Surfactant Protein D (SP-D) is a protein of the innate immune system that plays a role in maintaining surfactant homeostasis, clearance of pathogens, and control of inflammation, primarily in the lungs (1). However, its presence in extrapulmonary tissues, including the epithelial layers of the female reproductive organs, may have varying levels corresponding to hormonal fluctuations across the menstrual cycle. This research project aims to evaluate the changes in SP-D’s level throughout the menstrual cycle to determine the connection between immune defense and hormonal regulation across different phases.
Methods: The study employed the enzyme-linked immunosorbent assay (ELISA) to quantify the SP-D levels in plasma samples obtained from healthy volunteers.
Results: The samples investigated were part of the WASP study. The samples consisted of 19 individuals in Part A (one-time) and 7 in Part B (across a full menstrual cycle). Plasma concentrations of SP-D were higher in males, older individuals, and users of anti-inflammatory medications and non-contraceptive pills. However, the results were not statistically significant due to insufficient sample sizes. A drop in SP-D was observed in the luteal phase across Part B individuals’ cycles, with variations across different phases. In individuals with less hormonal fluctuations, fewer fluctuations in
SP-D levels were observed.
Conclusion: The lowered concentration of SP-D in the luteal phase may indicate a period where there may be an increase in the susceptibility to infections. However, this correlation cannot be drawn yet, as larger sample sizes are needed to validate these findings.
