POS1061 HYPOVITAMINOSIS D IN PSORIATIC ARTHRITIS PATIENTS: PREDICTIVE ROLE ON DRUG SURVIVAL OF METHOTREXATE MONOTHERAPY AND FIRST LINE OF b-DMARDs.

Abstract

BackgroundThe immunomodulatory role of vitamin D is extensively studied enough to hypothesize a pathogenetic role in chronic arthritis and psoriasis. Few data has been published on possible interference of hypovitaminosis D on drug response in rheumatoid arthritis patients, but data in psoriatic arthritis (PsA) patients is completely lacking.ObjectivesTo compare drug survival and retention rate of methotrexate (MTX) and the first line of biotechnological drugs (b-DMARDs) in PsA patients with hypovitaminosis D and those with normal level of vitamin D.MethodsWe conducted a retrospective study on 250 PsA patients (age 57,3 years ± 13,2). All patients were required to fulfill the CASPAR criteria for PsA and were tested for vitamin D levels at baseline visit. Clinical characteristics, MTX and first line of b-DMARDs treatment duration and comorbidities information were recorded for each patient. The evaluations of drug survivals were realized by Kaplan-Meier estimate, followed by log-rank (Mentel-Cox) test for the comparison between the groups of patients in study. Statistical significance was set at p ⩽ 0.05.ResultsSixty-four percent of PsA patients presented hypovitaminosis D (22,2ng/ml ± 8,8). PsA patients with hypovitaminosis D and those with normal levels were comparable for age (56,8 years ± 13 vs 58,5 years ± 12), and disease activity at baseline visit (DAS 28 VES: 4 ± 0,8 vs 3,8 ± 0,8).MTX monotherapy survival was shorter in hypovitaminosis D group (90 ± 19 weeks vs 166,8 ± 28 weeks, p=0,041), with discontinuation risk hazard ratio = 1,4 (95% CI: 1,005 – 2,014; p=0,046).The drug survival of first line of b-DMARDs was significantly shorter in patients with hypovitaminosis D (246,1 ± 40 weeks vs 302,1 ± 35 weeks; p=0,048), with discontinuation risk hazard ratio = 1,5 (95% CI: 1,1-2,4; p=0,05).ConclusionVitamin D seems play an important role not only in the regulation of immune system but also in the modulation on immune response induced by drugs, as MTX or b-DMARDs. The evaluation of sera levels of vitamin D at the begging of immunomodulatory therapy could have a predictive role on treatment management in PsA patients. Further studies should be useful to detect if supplementation of vitamin D could improve the performance of immunomodulatory drugs.Disclosure of InterestsNone declared