Introduction Psoriasis is a common chronic immune mediated

Introduction Psoriasis is a common, chronic, immune-mediated disorder of the skin that affects 2–3% of the population worldwide. In Asians, the incidence of psoriasis vulgaris is estimated at 0.05–0.3%. Patients present with a broad range of clinical manifestations with symptoms that vary in severity. The most common form of psoriasis is plaque-type psoriasis, seen in up to 80% of patients and characterized by patches of raised, red lesions covered by silver-white scales. Patients with psoriasis report a reduction in physical and mental functioning, resulting in a severely impaired quality of life, comparable with that seen in patients with cancer, arthritis, hypertension, annexin v disease, diabetes, and depression. Long-term use of common disease-modifying antirheumatic drugs (DMARDs), including methotrexate (MTX), cyclosporine, and retinoids, is limited by potential adverse effects and cumulative organ toxicities. Adalimumab has been investigated for the treatment of moderate to severe chronic plaque psoriasis based on recent findings implicating T lymphocytes and tumor necrosis factor (TNF) in the pathogenesis of plaque psoriasis. Adalimumab is a recombinant, fully human, anti-TNF-α monoclonal immunoglobulin G1 antibody, which binds both soluble and cell-bound forms of TNF-α with high affinity and specificity. Adalimumab neutralizes TNF-α activity by directly blocking its interaction with p55 and p75 cell surface TNF-α receptors as well as by modulating biological responses that are induced or regulated by TNF-α.
Methods Patients were started on adalimumab when they failed to respond or stopped responding to at least one other systemic treatment for psoriasis. Because of the severity of the patients\' disease, there was no washout time after treatment with previous systemic agents. According to the guidelines for the treatment of PsA with adalimumab, a dose of 40 mg was self-administered subcutaneously every other week, at Week 0, Week 2, Week 4, Week 6, Week 8, and Week 10. Efficacy was evaluated in all patients at baseline (Week 0) and at Week 2, Week 4, Week 8, and Week 12. Psoriasis disease activity was measured by calculating the PASI score. The PsA response achievement rate was defined, in accordance with the Psoriatic Arthritis Response Criteria (PsARC), as the percentage of patients who showed improvement in two or more of the following ways: (1) ≥ 30% decrease in the number of swollen joints counted; (2) ≥ 30% decrease in tender joints counted; (3) improvement in patient\'s global assessment of disease activity; or (4) improvement in physician\'s global assessment of disease activity. To qualify as an improved response, the patient must not have shown analogously defined worsening in any of these ways and must have shown improvement on at least one joint count. In addition to the response achievement rate, the Dermatology Life Quality Index (DLQI), a self-administered questionnaire, was evaluated in all patients to assess the effect of the skin disease on their daily activities. In total, 12 patients were included in the study [6 men (50%), 6 women (50%), mean age 41.7 years, range 25–59 years]. All of them completed the 12-week treatment. The mean baseline PASI score was 24.6, [standard deviation (SD) 11.7], and the initial PASI score of each patient was > 10. Five patients (42%) had a family history of psoriasis. With regard to PsA, the overall population of treated patients had baseline scores of 11 (SD 14) for swollen joint count, 18 (SD 11) for tender joint count, and 16.5 (SD 7.43) for DLQI. All patients had more than three joints involved at the outset of adalimumab treatment (Table 1). These values are consistent with long-standing moderate to severe psoriasis and PsA.
Results
Discussion Previous studies have shown that an initial loading dose of 80 mg followed by 40 mg every other week (eow) resulted in marked improvement of PASI scores. In the ADalimumab Effectiveness in Psoriatic Arthritis Trial (ADEPT), the double-blind, randomized, placebo-controlled study conducted by Mease et al, also showed 49% achievement of PASI 75 at Week 12. In another open-label study with a regimen of 40 mg every week, PASI 75 at Week 16 was achieved in 87% of 30 patients. An open-label retrospective study in Taiwan found that three of 13 patients (23%) had at least PASI 75 at Week 12 after receiving adalimumab 40 mg eow with a loading dose of 80 mg. In our study, 25% of the patients with a higher baseline PASI score demonstrated PASI 75 achievement at Week 12. The adalimumab dosage regimen used in our study to treat PsA, 40 mg eow without an initial loading dose, was a lower dosage compared to previous studies (Table 5). Asahina et al compared the efficacy of different adalimumab dosage regimens in their randomized, placebo-controlled study. Among the three treatment groups, composed of patients who received 40 mg eow, 80 mg eow, or 40 mg eow following an 80-mg loading dose, the most rapid response rate was found in patients receiving 40 mg eow plus the loading dose. PASI 75 achievement was highest in the group receiving 80 mg eow (81.0%). The reason the efficacy obtained in our study regarding plaque type psoriasis was lower than that obtained in clinical trials might be due to the lower dosage.