Romosozumab effect on neutrophil-to-lymphocyte ratio in post-menopausal women at high risk of fracture.

OBJECTIVES

Romosozumab (ROMO) is a monoclonal antibody targeting sclerostin (SOST), a key regulator of bone metabolism. It has been demonstrated that changes in SOST levels can affect distinct niches within the bone marrow that support haematopoiesis. This study investigated the effect of ROMO on complete blood count (CBC) parameters.

METHODS

We conducted a 12-month prospective observational study in post-menopausal women with severe osteoporosis treated with ROMO 210 mg/monthly over one year between October 2023 and April 2025. CBC values were assessed at baseline, 6 and 12 months. Absolute changes in CBC were assessed with a mixed model for repeated measures.

RESULTS

A total of 113 women (mean age of 73.4±9.7 years) were included. Neutrophils levels slightly decreased over time, with a significant decrease at 6 months (p=0.022), that was not sustained at 12 months (p=0.500). Haemoglobin and lymphocytes levels showed no significant differences over the period of the study. In the overall trend across time points, there was a statistically significant decrease in the neutrophil-to-lymphocyte ratio (NLR) over the 12 months (2.0 ± 1.1 at baseline, 1.8 ± 1.1 at month 6, and 1.8 ± 1.2 at month 12; p=0.034), with a small effect size (Cohen's δ = 0.22).

CONCLUSIONS

In post-menopausal women with severe osteoporosis, 12 months of ROMO treatment was associated with a statistically significant reduction in NLR, reflecting a potential modulation of systemic inflammation, though the clinical relevance of this modest shift remains uncertain and warrants further investigation.