52 patients that had previously participated in the RDBPC study of intralymphatic immunotherapy (ILIT) with 2 concomitant allergens, birch and grass, with NCT02423707, were eligible for an open follow up 5-6 years after treatment.

Bakground: Intralymphatic immunotherapy has been proposed as a new, more effective, modality for allergy immunotherapy. With ultrasound- guided injections into the lymph node the allergen is injected directly to the secondary lymphoid organ to stimulate the immune system. The protocol that has been used so far is three injections with one month interval. The effect have been evaluated in several studies with limited sample sized and the effect have been estimated to be in the same range as after conventinal subcutaneous immunotherapy. No long term follow up have been performed.

Objective: To investigate if the clinical improvement and immunological alterations is maintained 5-6 years after ILIT with two concomitant allergens, birch and grass.

Methods: 52 patients that had previously participated in the RDBPC study were asked to participate in this open follow up.

Inclusion Criteria:

- Moderate to severe allergic rhinitis to birch and grass pollen defined with a positive skin prick test and elevated allergen specific IgE antibodies

Exclusion Criteria:

• uncontrolled or perennial asthma
• other pulmonary disease
• known autoimmune or collagen disease
• chronic infection
• other significant disease
• severe atopic dermatitis
• use of beta blockers or angiotensin converting enzyme inhibitors as antihypertensive medications
• symptomatic sensitization to house dust mite or furry animals with daily exposure
• chronic upper airways disease
• pregnancy
• nursing
• obesity with BMI >30
• withdrawn informed consent