Serum interleukin-18 in patients with chronic ordinary urticaria: association with disease activity

Abstract

Interleukin (IL)-18 is a pleiotropic cytokine, which may play a role in autoimmune and allergic disorders. Serum IL-18 levels were measured in 34 patients with chronic ordinary urticaria (COU) and 17 normal subjects. In vivo and in vitro assays for histamine-releasing factors, an autologous serum skin test (ASST) and a basophil histamine release assay were also performed for all patients with COU. Serum IL-18 concentration was not significantly different between patients with COU and normal subjects (mean+/-standard error of the mean 246.47+/-18.40 pg/mL vs. 213.88+/-22.24 pg/mL), and no significant difference was found between ASST-positive and ASST-negative patients. However, in ASST-positive patients, IL-18 levels paralleled clinical severity scores and showed a tendency to correlate with in vitro histamine release. The increased IL-18 levels in the ASST-positive patients with most active chronic urticaria may reflect stronger immune system activation and possibly an involvement of IL-18 as a direct histamine-releasing factor.

Parameters Associated with Chronic Spontaneous Urticaria Duration and Severity: A Systematic Review

“…Both studies assessed disease severity as previously described by Sabroe et al [32]. Although both studies found higher levels of serum IL-18 in patients with severe disease, these did not reach statistical significance in one of the studies [3] and were only evident in ASST-positive patients in the other [31]. …”

“…Two articles [3,31] reported the relationship between interleukin 18 (IL-18) and CSU severity. IL-18 levels were measured by ELISA, with a lower limit of detection of 9.2 pg/ml [3] and by a sandwich enzyme immunoassay with a sensitivity of 12.5 pg/ml [31].…”

“…IL-18 levels were measured by ELISA, with a lower limit of detection of 9.2 pg/ml [3] and by a sandwich enzyme immunoassay with a sensitivity of 12.5 pg/ml [31]. Both studies assessed disease severity as previously described by Sabroe et al [32].…”

Increased circulating pro-inflammatory cytokines and imbalanced regulatory T-cell cytokines production in chronic idiopathic urticaria

“…This emphasizes that, besides the possibility of an intrinsic basophil defect, some circulating factors may favor the maintenance of activated basophils in the peripheral blood. Circulating cytokines, such as IL-18, have been suggested to be histamine-releasing factors, since IL-18 has been found at high levels in CIU patients with positive ASST in parallel with clinical severity scores [15].…”

“…Furthermore, inflammatory etiopathogenesis in CIU has been described as related to increased IL-4, IL-13, and IL-18 serum levels [13][14][15]. Cytokines in the circulation are a feature of amplified inflammation in chronic urticaria that may be helpful in understanding the immunopathogenesis of the idiopathic variety of chronic urticaria.…”