LAUSR

Objectives 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. Methods 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. Results 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 (<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.Abstract AB0914 – Figure 1 25-Hidroxyvitamin D3 levels in patients with Psoriatic arthritis with and without psoriasis skin involvement (ng/dL) Conclusions 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. Disclosure of Interest None declared