Background and aims

Psoriasis vulgaris is well-known as a chronic, recurrent, immune-mediated inflammatory disease with a conceded genetic predisposition. Neither the etiology of the psoriasis, nor specific laboratory markers for its disease activity have been clearly elucidated. Prolactin (PRL) acts as a cytokine with immunomodulatory functions, therefore it plays a role in skin biology. However, the results of PRL as a marker remains unclear.

The aim of this study was to confirm whether serum PRL levels reflect the activity of the disease or systemic complications, like inflammatory joint disease.

Methods

An observational study of a total of 21 patients (12 with and 9 without psoriatic arthritis) suffering from psoriasis vulgaris were included. The control group included 20 sex and age matched healthy individuals. In all patients, we determined skin disease activity according to the PASI index and joint activity in patients with psoriatic arthritis measured by DAPSA score. The concentration of PRL in the serum was measured by electrochemiluminescence method (ECLIA).

Results

The serum PRL levels were significantly higher in psoriatic patients (369.61 ±29.48mIU/L) compared to healthy individuals (152.30 ±7.49mIU/L), p<0.0001. Baseline prolactin demonstrated a significant positive correlation with the severity of psoriasis (r=0.984, p<0.0001). We noticed that correlations between HAMA and prolactin and DLQI and prolactin on group of psoriatic patients were not significant (p> 0.05), but correlation between HAMD and PRL is positive, medium-high and statistically significant (p <0.05). The PRL serum levels in active PsA (determined as 4 swollen and tender joints) were significantly higher than in PV patients and controls, p<0.0001 and p=0.002, respectively, even though, we had two subgroups with a compact number of patients.

Conclusion

Our results showed that PRL serum levels are a marker of local skin activity and also of systemic complication like active arthritis.