What is the evidence of helminth infections following anti-Interleukin-5 (IL-5) therapy?

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From the Guidelines

There is limited evidence regarding helminth infections following anti-IL5 therapy, but patients on this therapy should be monitored for potential parasitic infections due to the theoretical risk of increased susceptibility. Anti-IL5 medications like mepolizumab, reslizumab, and benralizumab, which are used to treat severe eosinophilic asthma, theoretically could increase susceptibility to helminth infections since they reduce eosinophils that play a key role in the immune response against parasitic worms. However, clinical trials and post-marketing surveillance have not demonstrated a significant increase in helminth infections in patients receiving these therapies, as noted in the european position paper on rhinosinusitis and nasal polyps 2020 1. The theoretical risk exists because eosinophils are important for fighting parasitic infections, as they release toxic granule proteins that damage the parasites.

Some key points to consider in patients on anti-IL5 therapy include:

  • Monitoring for potential parasitic infections, especially in patients who live in or travel to areas endemic for helminth infections
  • Watching for symptoms such as unexplained gastrointestinal issues, weight loss, or anemia
  • Considering screening for parasitic infections before initiating anti-IL5 therapy in patients with high-risk exposure history, although this is not a formal recommendation in most guidelines, including the european position paper on rhinosinusitis and nasal polyps 2020 1.

It is essential to weigh the benefits of anti-IL5 therapy against the potential risks, including the theoretical risk of increased susceptibility to helminth infections, and to make informed decisions based on the most recent and highest quality evidence available.

From the FDA Drug Label

Eosinophils may be involved in the immunological response to some helminth infections. Patients with known parasitic infections were excluded from participation in clinical trials. It is unknown if NUCALA will influence a patient’s response against parasitic infections. Treat patients with pre-existing helminth infections before initiating therapy with NUCALA If patients become infected while receiving treatment with NUCALA and do not respond to anti-helminth treatment, discontinue treatment with NUCALA until infection resolves.

The evidence of helminth infections following anti-Interleukin-5 (IL-5) therapy with mepolizumab is unknown. Patients with known parasitic infections were excluded from clinical trials, and it is recommended to treat pre-existing helminth infections before initiating therapy with mepolizumab. If a patient becomes infected while receiving treatment, therapy with mepolizumab should be discontinued until the infection resolves 2. Key points:

  • Eosinophils are involved in the immunological response to helminth infections
  • Patients with known parasitic infections were excluded from clinical trials
  • Treatment of pre-existing helminth infections is recommended before initiating mepolizumab therapy
  • Discontinue mepolizumab therapy if a patient becomes infected and does not respond to anti-helminth treatment

From the Research

Helminth Infections Following Anti-IL-5 Therapy

There is no direct evidence in the provided studies to suggest a link between helminth infections and anti-Interleukin-5 (IL-5) therapy.

  • The studies primarily focus on the effects of anti-IL-5 therapy on eosinophilic disorders, asthma, and hypereosinophilic syndromes 3, 4, 5, 6, 7.
  • None of the studies mention helminth infections as a consequence of anti-IL-5 therapy.
  • The evidence provided discusses the efficacy and safety of anti-IL-5 therapies in reducing eosinophil counts, improving symptoms, and enhancing quality of life in patients with eosinophilic disorders 3, 4, 5, 6, 7.
  • However, it is essential to note that helminth infections are typically associated with eosinophilia, and anti-IL-5 therapy may potentially impact the course of these infections.
  • Further research is needed to investigate the relationship between anti-IL-5 therapy and helminth infections, as the current evidence does not provide sufficient information to draw conclusions 3, 4, 5, 6, 7.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Anti-IL-5 therapies for asthma.

The Cochrane database of systematic reviews, 2022

Research

Anti-interleukin-5 (mepolizumab) therapy for hypereosinophilic syndromes.

The Journal of allergy and clinical immunology, 2004

Research

Long-Term Therapy Response to Anti-IL-5 Biologics in Severe Asthma-A Real-Life Evaluation.

The journal of allergy and clinical immunology. In practice, 2021

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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