Allergen-specific immunotherapy is the only causative treatment of IgE-mediated allergic disorders. The most common administration route is subcutaneous, which may necessitate more than 50 allergen injections during 3 to 5 years. Recent evidence suggests that direct intralymphatic injections could yield faster beneficial results with considerably lower allergen doses and markedly reduced numbers of injections.

To evaluate the effects of intralymphatic allergen-specific immunotherapy in pollen-allergic patients.

In an open pilot investigation followed by a double-blind, placebo-controlled study, patients with allergic rhinitis were treated with 3 intralymphatic inguinal injections of ALK Alutard (containing 1000 SQ-U birch pollen or grass pollen) or placebo (ALK diluent). Clinical pre- and posttreatment parameters were assessed, the inflammatory cell content in nasal lavage fluids estimated, and the activation pattern of peripheral T cells described.

All patients tolerated the intralymphatic immunotherapy (ILIT) treatment well, and the injections did not elicit any severe adverse event. Patients receiving active treatment displayed an initial increase in allergen-specific IgE level and peripheral T-cell activation. A clinical improvement in nasal allergic symptoms upon challenge was recorded along with a decreased inflammatory response in the nose. In addition, these patients reported an improvement in their seasonal allergic disease. No such changes were seen in the placebo group.

Although this study is based on a limited number of patients, ILIT with grass-pollen or birch-pollen extracts appears to reduce nasal allergic symptoms without causing any safety problems. Hence, ILIT might constitute a less time-consuming and more cost-effective alternative to conventional subcutaneous allergen-specific immunotherapy.