RANK-RANKL-OPG System in COVID-19: Examining the Pathway Among Healthcare Workers in Nigeria

<i>Background</i>: Coronavirus disease 2019 (COVID-19) influences bone metabolism by altering the RANK-RANKL-OPG system. However, this has not been validated, especially among Nigerians. Consequently, the current study explored the influence of the disease on this vital skeletal pathway among Nigerian healthcare workers (HCWs). <i>Methods</i>: This was a prospective longitudinal study conducted in the Department of Chemical Pathology of the Rivers State University Teaching Hospital among HCWs in Rivers State, Southern Nigeria. Eligible HCWs (n=76) with moderate RT-PCR-confirmed COVID-19 were recruited and compared with age and sex-matched healthy controls. Demographic, anthropometric, clinical, and laboratory data were obtained at baseline upon COVID-19 onset and followed up on days four and seven. Statistical analysis was done using descriptive/inferential statistics at a p-value <0.05. <i>Results:</i> The HCWs with moderate COVID-19 had higher serum levels of pro-inflammatory markers (IL-1β, IL-6, TNF-α) and receptor activator of nuclear factor kappa beta ligand (RANKL) but lower serum levels of osteoprotegerin (OPG) t COVID-19 diagnosis compared to the healthy controls (p<0.05). Among the HCWs with positive COVID-19 status, an increasing trend of these inflammatory markers and RANKL was observed from day one to day four and day seven, but a decreasing trend of OPG levels was observed (p<0.05). On day seven following COVID-19 diagnosis among the HCWs, a positive relationship was established between serum RANKL and all the pro-inflammatory markers (p<0.001) while an inverse relationship was only observed between OPG and IL-1β pro-inflammatory marker (p<0.05). <i>Conclusion:</i> The study findings corroborate the negative influence of COVID-019 on the RANK-RANKL-OPG system in favor of exaggerated osteoclastogenesis.