Correlation of IFN-α gene expression with plasma IFN-α levels and 25-OH vitamin D3. Plasma levels of IFN-α and gene expression levels were quantified by ELISA and RT-PCR respectively. (A) Plasma levels of IFN-α positively correlated with gene expression (2 – Δct) of IFN-α. (B) IFN-α gene expression (2 – Δct) correlated negatively with plasma levels of 25-OH vitamin D3. Dots represent individual samples. Correlation analysis was performed by Spearman’s correlation coefficient. A P value less than 0.05 was considered as significant. IFN-α, interferon alpha.
Mandal et al. Arthritis Research & Therapy 2014 16:R49 doi:10.1186/ar4479