Intralymphatic Immunotherapy Safe But Ineffective

Investigators found that intralymphatic immunotherapy of was not superior to placebo or other forms of allergen-specific immunotherapy, but felt continued research was warranted.

Recent research suggested that intralymphatic immunotherapy has a potential role in the treatment of allergic rhinitis in patients, though its efficacy must be challenged in future trials.

In the recent study, Norhayati Mohd Noor, PhD, Department of Family Medicine, School of Medical Sciences, University Sains Malaysia, Kelantan, confirmed the safety of the potential treatment but could not confirm its full efficacy, possibly due to the high variation recorded throughout the trials.

According to investigators, self-reported allergic rhinitis is reported to be approximately 25% in children and more than 40% in adults, and has been linked to asthma in 15%-38% of patients with the condition.

A common form of allergen-specific immunotherapy, sub-lingual immunotherapy, has been considered patient-friendly and effective. But concerns had been raised over the long duration of treatment (30-80 allergen injections over 3-5 years) as well as potential allergic side effects.

Intralymphatic immunotherapy, another form of allergen-specific immunotherapy, was considered as a treatment option that could transcend the limitations of sub-lingual immunotherapy.

Intralymphatic immunotherapy is complete after only 3 injections, and when given 4 weeks apart, intralymphatic immunotherapy is reported to be safe and effective for up to 3 years.

In their study, Noor and colleagues set out to determine the safety and efficacy of the treatment.

The Study

A systemic review and meta-analysis were undertaken in the beginning of the study.

The meta‐analyses were done using Review Manager 5.3.5 software, and the statistical analyses were performed using the random‐effects model and the results expressed as risk ratio for dichotomous outcomes and mean difference for continuous outcomes with 95% confidence intervals.

Searches for randomized clinical trials and case‐control studies comparing with placebo or conventional allergen-specific immunotherapy in patients diagnosed with allergic rhinitis were also conducted.

Ongoing trials were searched through the World Health Organization WHO International Clinical Trials Registry Platform.

A total of 285 records were retrieved, and 452 participants were enrolled in the included trials, several of which involved intervention and control groups. Most trials used a single allergen as the intralymphatic immunotherapy intervention.

The Findings

The investigators found that intralymphatic immunotherapy showed no difference for local swelling at the site of injection in 8 of the included trialscompared to placebo (RR 4.51, 95% CI 0.81 to 25.06; p = 0.090; I2 = 88%; 8 trials, 228 participants; low certainty evidence).

Likewise, no difference was documented for other adverse events between intralymphatic immunotherapy and placebo.

Only 2 severe adverse reactions were reported following the introduction of intralymphatic immunotherapy. Additionally, investigators reported that 1 trial was inconsistent with the administration of the therapy, opting for 2-week intervals instead of the common 4-week interval.

Overall, the results of the study contradicted of previous meta-analyses, with high heterogeneity among the trials possibly contributing to the lack of efficacy found in the study.

Despite this, Noor and colleagues believed further research was necessary.

“This review found (intralymphatic immunotherapy) is safe but not effective, which could be contributed by the high variation amongst the trials,” the team wrote. “Future trials should involve larger numbers of participants and report standardized administration of ILIT and outcome measures.”

The study, “Efficacy and safety of intralymphatic immunotherapy in allergic rhinitis: A systematic review and meta-analysis,” was published in Clinical and Translational Allergy.