AB0914 Comparison of 25-hydroxyvitamin d3 serum levels in patients with psoriatic arthritis with or without psoriasis skin involvement
Authors: C. Pijoan-Moratalla, J.R. Quiñones-Torres, M. Vázquez-Díaz
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Objectives</h3> To determine 25-hydroxyvitamin D3 (25OH-D3) serum levels in patients with psoriatic arthritis (PA) and to assess differences according to the presence or absence of psoriasis skin involvement. To evaluate the response to vitamin D oral supplements in case of deficiency in both groups. <h3>Methods</h3> We conducted an observational retrospective study including patients with diagnosis of PA according to the CASPAR classification criteria who had at least one serum determination of 25OH-D3 in the last 36 months. Clinical and epidemiological data were collected, including arthritis distribution, age of diagnosis, presence of psoriasis skin involvement, treatment received and serum 25OH-D3 levels at baseline and within the subsequent 3 months if treatment with oral supplements had been initiated. Patients already receiving oral vitamin D supplements at baseline were excluded. <h3>Results</h3> Sixty patients met the inclusion criteria and were analysed. 42 were female (70%), with a mean age of 47.6 years (range: 30–82). Psoriasis skin involvement was present in 40 patients and preceded onset of arthritis in 80% of them (20% with psoriatic nail dystrophy). Regarding 25OH-D3 levels, mean value was 17.99±13.23 ng/dL. In the global analysis, 7 patients (11.6%) had levels between 0–10 ng/dL, 22 patients (36.6%) between 10–20 ng/dL, 23 patients (38.3%) between 20–30 ng/dL, 6 patients (10%) between 30–40 ng/dL and 2 patients had ≥40 ng/dL. In our sample, 58.53% of patients with psoriasis skin involvement had 25OH-D3 levels higher than 20 ng/dL, in contrast to the group without skin involvement, who reached sufficiency levels only in 37.5% of the cases. In the comparative analysis, patients with psoriasis skin involvement had a mean 25OH-D3 serum level of 20.88 ng/dL whereas patients without skin involvement had lower levels (mean value 19.42 ng/dL). Similarly, patients with skin psoriasis had more frequently 25OH-D3 levels between 20–30 ng/dL (insufficiency) compared to those without this manifestation, who presented lower levels (44% vs 16%) but without statistically significant difference. Results are shown in Figure 1. Finally, all patients presenting 25OH-D3 deficiency at baseline (&lt;20 ng/dL) were treated with oral supplements (calcifediol 0.266 mg every two weeks). Of them, 23 patients had a second determination of 25OH-D3 within the subsequent 3 months, with only 13 patients reaching sufficient levels (56%), whereas the rest did not respond to the dose administered. No statistically significant differences were found in the response depending on the presence or absence of cutaneous psoriasis. <h3>Conclusions</h3> In patients with PA, the presence of psoriasis skin involvement correlates with higher 25OH-D3 serum levels. This finding could be explained by the treatment received in these patients for moderate-severe skin involvement, which includes topical vitamin D analogues and phototherapy that could increase 25OH-D3 serum levels. After oral supplements, there was no statistically significant difference in the percentage of patients that reached sufficiency levels in both groups. <h3>Disclosure of Interest</h3> None declared