New research suggests that inflammation levels in females with sickle cell disease (SCD) vary across the menstrual cycle, potentially contributing to the timing of painful vaso-occlusive episodes (VOEs).
In a study analysing blood samples from reproductive-aged women with SCD, researchers found that levels of C-reactive protein (CRP), a key marker of inflammation, were significantly higher during the follicular phase of the menstrual cycle compared to the luteal phase. Median CRP levels measured 8.80 mg/L in the follicular phase versus 0.82 mg/L in the luteal phase (p=0.03).
While previous research has established that women with SCD experience more frequent and severe VOEs than men, this is the first study to examine inflammatory marker fluctuations across the menstrual cycle in this population. The findings may explain why many women with SCD report VOEs around their menstrual period.
CRP levels were not influenced by SCD genotype (SS vs SC), sex, or use of hydroxyurea, a common treatment for SCD, further emphasising the role of menstrual cycle–related factors in inflammation and pain.
The authors suggest that this cyclical variation in inflammation may increase susceptibility to VOEs during specific phases of the cycle, particularly the follicular phase. They call for prospective studies to confirm the link between menstrual cycle phases, inflammation, and VOEs, and to explore whether targeted interventions could reduce pain episodes in affected women.
Reference
Wu J et al. C-reactive protein and the menstrual cycle in females with sickle cell disease. Blood Vessels, Thrombosis & Hemostasis. 2025;doi.org/10.1016/j.bvth.2025.100067.
