In a recent study, researchers from University Hospital of Split, Croatia investigated the relationship between Vitamin D, Interferon-gamma (INF-gamma) and Estradiol in females of childbearing age with inactive Systemic Lupus Erythematosus (SLE). The paper entitled “Relationship between vitamin D, IFN-c, and E2 levels in systemic lupus erythematosus” was published in the Lupus journal.
Systemic Lupus Erythematosus (SLE) is a chronic disease characterized by several immune system disorders, one of which concerns the abnormal production of cytokines – secreted signaling proteins involved in immune responses. A special type of cytokines called interferons and in particular INF-gamma, have an essential role in SLE development and severity. SLE patients have low vitamin D levels, an important immunomodulator, and accumulating evidences suggest that vitamin D is associated with disease outbursts. Estradiol, the primary female sex hormone, besides regulating estrous and menstrual cycles is also an immunomodulating molecule that might contribute to SLE pathophysiology. In this study, scientists measured the blood serum levels of each of these molecules in SLE and control patients to investigate whether there is a correlation between these immunomdulators and SLE development.
Researchers focused on females of childbearing age with inactive SLE, since disease frequency in women of this age group is 10-15 times higher than in women of other ages. In total, 22 SLE patients and 21 healthy subjects of the same gender and ages were included in the work. The researchers found that the SLE group presented higher values of INF-gamma and estradiol and lower levels of vitamin D compared to the control group. In SLE patients, the team found a negative correlation between INF-gamma and vitamin D levels and a positive correlation between INF-gamma and estradiol levels. These findings support the previously raised notion that SLE patients might benefit from vitamin D supplementation and that indirect INF-gamma inhibitors might also be useful in treating SLE and deserve to be investigated further.
Overall, this study showed there is an interesting interplay between vitamin D, INF-gamma and estradiol in patients with inactive SLE. Nonetheless, it still remains unanswered whether these relationships are a cause or a consequence of the disease, with further studies necessary to clarify these findings.