Intralymphatic injections of standard grass-pollen extract are well tolerated and could offer a new and convenient option for treating grass-pollen allergy, new research suggests.

The therapy involves ultrasound-guided injection into the right inguinal lymph node, and requires only three preseasonal doses, given 1 month apart, explained investigator Amber Patterson, MD, from Nationwide Children’s Hospital in Columbus, Ohio.

Intralymphatic immunotherapy is similar to subcutaneous immunotherapy “in that you do your course of treatment, but then you’re done,” without the monthly injections for 3 to 5 years, she explained.

In several European trials, it has been demonstrated that intralymphatic injections are effective against grass, birch, and cat.

“When I first read about this in Europe, I thought, ‘this is incredible, we need to be doing this here.’ It’s so nice to have options since a lot of people don’t do traditional allergy shots because it’s so inconvenient,” Dr Patterson told Medscape Medical News.

“The Europeans followed people 3 years out and saw sustained efficacy, so we’re banking on that,” she added.

Results from the study by Dr Patterson’s team were presented as a late-breaking poster here at the American Academy of Allergy, Asthma & Immunology 2015.

First Evidence

The double-blind trial involved 15 teenagers with grass-pollen-induced rhinoconjunctivitis, three of whom also reported mild intermittent asthma.

The patients were randomly assigned to receive three intralymphatic injections of either extract from North American grass pollen or placebo, administered at least 4 weeks apart and timed to be completed before the start of the grass-pollen season.

Escalating doses — 0.1 mL, 0.2 mL, and 0.5 mL — were administered with a 1.5-inch 25-gauge needle inserted into the subcapsular node space, Dr Patterson explained.

“The main aim was to show that we could take American extracts, which are standardized differently than European extracts, and that we could do this safely,” she said.

Patients were assessed for adverse safety events — such as erythema, pruritus, and edema — 2 and 5 hours after the injection and then 1 week later. There were no differences in safety scores between the treatment and placebo groups.

Of note, all the teenagers completed 100% of their injections, Dr Patterson reported. “When I told other allergists this, they were so surprised; you hardly ever see this kind of compliance.”

When she was asked about allergists’ access to ultrasound guidance for the injections, Dr Patterson explained that “we need to figure out the science first. Once that’s more established, we can figure out how to give the shots because it’s a pretty simple procedure.”

“It’s interesting,” said Hugh Sampson, MD, from Kravis Children’s Hospital at Mount Sinai in New York City, who was not involved in the study.

“It does seem safe and, if you can do it in three doses, you’re definitely going to get better compliance,” he told Medscape Medical News.