Biomarkers for Monitoring Treatment Response of Omalizumab in Patients with Chronic Urticaria

Eosinophilic cationic protein and D-Dimer are potential biomarkers to predict response to antihistamines but not to omalizumab in chronic spontaneous urticaria

INTRODUCTION

Biomarkers that could reliably anticipate the effectiveness of antihistamines and omalizumab in treating chronic spontaneous urticaria (CSU) have not been conclusively identified. Our objective was to examine how eosinophilic cationic protein (ECP), tryptase, D-dimer, and total Immunoglobulin E (IgE) impact the response to antihistamine and omalizumab treatments in individuals with CSU.

METHODS

In this cross-sectional retrospective study, CSU patients that had undergone treatment with either antihistamines or omalizumab for a minimum of 12 weeks between 2015 and 2021 at an Allergy and Immunology Department were analyzed. Several demographic and laboratory parameters including eosinophil counts, mean platelet volüme (MPV), sedimentation, C-reactive protein (CRP), antinuclear antibodies (ANA) and Anti-thyroperoxidase (Anti-TPO) and total IgE, tryptase, ECP and D-dimer were retrived from patient files. The association of these biomarkers with Urticaria Control Test (UCT) and the effect of these biomarkers on treatment response were evaluated. Treatment response was assessed using the UCT, with a score of UCT ≥ 12 indicating a responder and UCT < 12 indicating a non responder.

RESULTS

The patients in the omalizumab group were older, had a longer disease duration and had worse urticaria control (lower baseline UCT scores). 421 patients were treated with antihistamines and 88 patients were treated with omalizumab. ECP was found to be inversely correlated with baseline UCT (p < 0.001 r=-0.268). ECP and D-dimer levels of non-responder patients in the antihistamine group were significantly higher than in responder patients (ECP: 49 ng/mL vs 28.1 ng/mL, p < 0.001) (D-dimer: 0.60 mg/L vs 0.30 mg/L, p < 0.001), while there were no significant difference in terms of tryptase and total IgE. These four biomarkers were similar, in omalizumab responders and non responders.

CONCLUSION

In this study with CSU, we looked at predictors of responses to treatments. ECP can serve as a marker of poor urticaria control and may predict antihistamine refractoriness along with D-dimer.

Cost-effective omalizumab dosage for chronic urticaria: a systematic review and network meta-analysis

Chronic urticaria is a persistent skin condition characterized by recurrent wheals (hives) and/or angioedema lasting more than six weeks, significantly impacting quality of life and often requiring long-term management. Limited access to costly treatments like omalizumab poses challenges in low-income countries with high healthcare expenses and limited insurance coverage, prompting research into cost-effective dosages for effective management. This study aims to find the most cost-effective dosage for treating chronic urticaria in countries with healthcare affordability challenges. PubMed, MEDLINE, and Web of Science databases were searched for randomized controlled trials (RCTs) from January 1, 2010, to October 29, 2023. Studies assessing Omalizumab's efficacy in chronic spontaneous urticaria (CSU) patients unresponsive to antihistamines were included. Network meta-analyses (NMAs) were conducted using the "multinma" package in R, employing Bayesian random-effects models to synthesize data from multiple studies. Each outcome underwent separate analysis, with effect sizes illustrated via forest plots generated using Plotly in R. Individual studies' risk of bias was assessed using the Cochrane Risk of Bias Tool 2, and effect estimate certainty was rated via the GRADE approach. Consistency assumption was evaluated using the unrelated mean effects (UME) model, focusing on each data point's contribution to model fit. Present study showed that the 300 mg dose outperformed others and placebo in reducing urticaria activity score over 7 days (UAS7), weekly itch severity score (WWS), and weekly number of hives score (WIS). Response rates were notably higher with 300 mg, indicating its superiority in achieving treatment response. Given the significantly greater effect sizes of 150 mg and 300 mg over 75 mg and placebo, low doses aren't recommended for antihistamine-resistant cases. Initiating treatment with either a 300 mg dose for six months or starting with 150 mg and adjusting upwards as necessary is recommended, aligning with economic considerations until optimal dosages are established.

Key differences between chronic inducible and spontaneous urticaria

Introduction

The latest international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for urticaria recommends limited laboratory testing for chronic spontaneous urticaria (CSU) and selective testing for only certain chronic inducible urticaria (CIndU) subtypes, though the rationale for these recommendations is poorly explained. This study aimed to improve the understanding of CIndU subtypes by comprehensively comparing their demographic, clinical, and laboratory characteristics with those of the better-characterized CSU.

Methods

We conducted a retrospective analysis of 567 patients (median age 41 years, 67% female) diagnosed with CSU, symptomatic dermographism (SD), cold urticaria (ColdU), cholinergic urticaria (CholU), and delayed pressure urticaria (DPU).

Results

Our findings revealed that patients with SD, ColdU, and CholU had lower levels of C-reactive protein (CRP), higher total serum immunoglobulin E (IgE) levels, and higher basophil counts compared to CSU patients. These subtypes also had distinct demographic and clinical features, such as a younger age of onset and a longer disease duration. In contrast, patients with DPU had significantly higher CRP levels and neutrophil counts compared to those with CSU.

Discussion

These findings highlight the heterogeneity among chronic urticaria subtypes, suggesting that a tailored approach to laboratory testing may be more effective. The distinct immunological and clinical features observed in CIndU subtypes suggest a need for subtype-specific diagnostic and therapeutic guidelines.

Characterization of omalizumab updosing patterns and predictive factors in chronic spontaneous urticaria: A prospective multicentric observational study

BACKGROUND

Limited information is available on the use of omalizumab (OMA) updosing since its introduction as a second-line therapy in chronic spontaneous urticaria (CSU) in 2014. Practical guidelines from health authorities are lacking, and the specific characteristics of patients requiring higher doses remain unknown. Our objectives were to characterize the patterns of OMA updosing (defined as changes in dose and/or injection intervals), to identify the predictive factors associated with updosing, and to improve CSU management.

METHODS

We conducted a prospective, multicentric, real-life observational study, including patients diagnosed with CSU and starting OMA. The data were collected at 0, 3, 6, and 9 months. The primary endpoint was the frequency of OMA updosing at 3 months. The secondary endpoints included an analysis of updosed patients' profile, and an assessment of OMA efficacy and safety.

RESULTS

We included 153 patients. Twenty percent of patients were updosed at 3 months, and 27% in total during the 9-month follow-up. Practitioners mainly chose to increase the frequency of injections (66%). At baseline, the updosed patients were more likely to have more severe CSU (UCT < 4, p < 0.030), a lower lymphocyte count (<2000/mm3, p = 0.037), and low IgE levels (<70 UI/mL, p = 0.024). The side effects of OMA were not more frequent after updosing.

CONCLUSION

One in five patient underwent updosing within just 3 months. OMA updosing is frequent in particular in cases of severe disease and low IgE blood levels.

Chronic Urticaria in Special Populations: Pediatric, Pregnancy, and the Elderly

Chronic urticaria is an inflammatory skin disorder defined by the presence of evanescent erythematous pruritic wheals, angioedema, or both. While treatment guidelines are continuing to become more clearly defined, there is still a gap in the medical literature surrounding chronic spontaneous urticaria (CSU) treatment in vulnerable populations such as children (aged 0-18 years), pregnant women, and the elderly (aged >65 years). The purpose of this review is to provide an update on CSU in each of these special population categories by defining prevalence, identifying diagnostic considerations, and exploring current and future management options.

Omalizumab withdrawal outcomes in chronic spontaneous urticaria are linked with baseline IgE and eosinophil levels

Background

Chronic Spontaneous Urticaria (CSU) is an immune-mediated skin disease that may require prolonged treatments. Currently, there are no recommendations for treatment discontinuation once CSU symptoms are controlled, particularly among patients primarily diagnosed with severe CSU.

Objective

In this real-life study we aimed to describe our experience of omalizumab (Oma) treatment withdrawal in CSU and define biomarkers related to these outcomes.

Methods

CSU patients followed at our allergy clinic from January 2016 to December 2022 were included. Response to Oma therapy, and Oma-withdrawal outcomes among patients who reached complete remission for >6 months were analyzed.

Results

During the study period 192/335(%) CSU patients were categorized as severe-CSU and entitled to receive Oma according to our country's regulations. Of them, 131/192(68%) were considered "Oma-responders", and 95/131(72.5%) patients underwent gradual treatment withdrawal. Successful Oma-withdrawal was documented in 47/95(49.5%) whereas 48/95(50.5%) patients experienced flare and were defined as unsuccessful OMA-withdrawal. The first was associated with shorter disease duration 7.1 ± 7.4 years vs. 10.7 ± 9.4 (P = 0.042), lower baseline-IgE 81.6 ± 84.1IU/ml vs. 324.7 ± 555.9 (P = 0.005), and lower baseline-eosinophils count 131.4 ± 110.5 vs. 195.6 ± 98.4 (P = 0.043) in comparison to failure of Oma-withdrawal group.

Conclusion

OMA may be successfully withdrawn in up to 50% of severe CSU patients following complete remission of disease symptoms, utilizing a gradual withdrawal protocol. Oma-withdrawal failure was linked with longer duration of disease as well as high IgE and eosinophil counts prior to initiation of Oma therapy. These parameters may enable the design of a treatment withdrawal algorithm.

The Alarmin Triad-IL-25, IL-33, and TSLP-Serum Levels and Their Clinical Implications in Chronic Spontaneous Urticaria

This study delves into the critical role of alarmins in chronic spontaneous urticaria (CSU), focusing on their impact on disease severity and the quality of life (QoL) of patients. We investigated the alterations in alarmin levels in CSU patients and their correlations with the Urticaria Activity Score (UAS7) and the Dermatology Life Quality Index (DLQI). We analyzed serum levels of interleukin-25 (IL-25), interleukin-33 (IL-33), and thymic stromal lymphopoietin (TSLP) in 50 CSU patients, comparing these to 38 healthy controls. The study examined the relationship between alarmin levels and clinical outcomes, including disease severity and QoL. Elevated levels of IL-33 and TSLP in CSU patients (p < 0.0001) highlight their potential role in CSU pathogenesis. Although IL-25 showed higher levels in CSU patients, this did not reach statistical significance (p = 0.0823). Crucially, IL-33's correlation with both UAS7 and DLQI scores underscores its potential as a biomarker for CSU diagnosis and severity assessment. Of the alarmins analyzed, IL-33 emerges as particularly significant for further exploration as a diagnostic and prognostic biomarker in CSU. Its substantial correlation with disease severity and impact on QoL makes it a compelling candidate for future research, potentially serving as a target for therapeutic interventions. Given these findings, IL-33 deserves additional investigation to confirm its role and effectiveness as a biomarker and therapeutic target in CSU.