An Insight on the Possible Association between Inflammatory Bowel Disease and Biologic Therapy with IL-17 Inhibitors in Psoriasis Patients.

Psoriasis is a chronic, inflammatory, multisystemic disease which affects approximately 2-3% of the population globally, whose onset is triggered by genetic and environmental factors which activate both dendritic cells and keratinocytes, resulting in the production of proinflammatory cytokines such as tumor necrosis factor alpha, interleukin 17, interleukin 23, interleukin 22, and interleukin 1ß. An in-depth understanding of the pathophysiology of psoriasis led to significant advances in the development of safe and efficient novel therapeutic options, with four classes of biologic therapy being approved for the management of moderate to severe psoriasis: tumor necrosis factor alpha inhibitors, interleukin 23 inhibitors, anti-interleukin 12/23 agents, anti-interleukin 17 agents, as well as small-molecule inhibitors, such as apremilast. Psoriasis is associated with comorbid conditions, namely psoriatic arthritis, cardiovascular disease, metabolic syndrome, psychiatric disorders, malignancy, as well as inflammatory bowel disease. For patients affected by both psoriasis and inflammatory bowel disease, there is a strong recommendation to avoid IL-17 inhibitors since they may play a part in the exacerbation of the gastrointestinal disease. Our aim was to perform a thorough literature review regarding the development of inflammatory bowel disease lesions in psoriasis patients treated with IL-17 inhibitors, along with a case presentation to emphasize the need for close follow-up of these patients.

Cutting Edge: Homeostasis of Innate Lymphoid Cells Is Imbalanced in Psoriatic Arthritis.

Innate lymphoid cells (ILC) have a high potency for cytokine production independent of specific Ag stimulation. Imbalance of ILC subsets may influence cytokine production in humans and hence be associated with the development of inflammatory disease. Evidence for an imbalance of ILC homeostasis in human disease, however, is very limited to date. In this study we show that psoriatic arthritis (PsA), a severe disease of the joints depending on the activation of the IL-23/IL-17 pathway, is characterized by a skewed ILC homeostasis. Circulating ILC3s as potent source of IL-17/IL-22 were elevated in active PsA, whereas ILC2s, which produce proresolving cytokines, were decreased. The ILC2/ILC3 ratio was significantly correlated with clinical disease activity scores and the presence of imaging signs of joint inflammation and bone damage. Multivariable analysis showed that a high ILC2/ILC3 ratio is associated with remission in PsA, suggesting that specific alterations of ILC homeostasis control disease activity in PsA.

Risk of active tuberculosis in patients with inflammatory arthritis receiving TNF inhibitors: a look beyond the baseline tuberculosis screening protocol.

Tuberculosis (TB) is a major concern in patients receiving TNF inhibitors (TNFi). This study aimed to assess the incidence of active TB and the efficacy of TB prevention measures used over the years, and to determine risk factors for developing TB, in a single-centre cohort of patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosing spondylitis (AS) receiving TNFi. Data of all patients in whom treatment with TNFi was initiated in our rheumatology clinic until December 1st 2014 have been retrospectively analysed. The cohort was divided into 3 groups per the mandatory LTBI screening method at baseline: tuberculin skin test (TST) with a positive threshold of either 10 mm (group TST1), or 5 mm (group TST2), and QuantiFERON®-TB Gold test (group QFT). The incidence of active TB was analysed for each group and compared to TB incidence data in general population. Five hundred fifty patients were included (305 RA, 42 PsA, 203 AS); 97 patients belonged to the TST1, 229 to the TST2 and 224 to the QFT group. The number of active TB cases/time of exposure to TNFi (person-years, PY) was 8/593.5, 9/1044.0 and 3/555.3, respectively, accounting for an incidence of 1348.0, 862.1 and 540.2 cases per 105 PY. Active TB cases occurring in the first year of TNFi treatment (early TB) per total TB cases were only 3/8, 1/9 and 1/3, respectively, too few to identify statistically significant differences between the 3 LTBI screening protocols. However, less TB cases per total observation time were registered in the QFT group, probably due to the reduced duration of exposure to TNFi. All cases of active TB were registered among patients receiving monoclonal antibodies TNFi agents. We have found no significant risk factors for developing active TB. In our cohort, TB occurring after 1 year of TNFi treatment exceeds 'early TB', suggesting the necessity of further TB prevention measures besides baseline screening for LTBI.