15 patients with moderate to severe allergic rhinitis against grass were recruited and enrolled in the study. They received three open label intralympatic grass allergen injections with the dose 1000 SQ-U each and with one month interval. The next year the patients were randomized double blind to an active or placebo booster injection of 1000 SQ-U before the pollen season. Grass specific IgG4 levels were measured before and at various time ponts after treatment.

The purpose of the study is to evaluate whether intralymphatic administration of AIT is a safe and effective treatment for patients with pollen-induced allergic rhinitis. The long term goal is to provide a base for a more efficient administration of ASIT, which will reduce both the dose necessary and the number of clinic visits associated with the conventional subcutaneous ASIT.

The aim of the present substudy is to evaluate if a randomized preseasonal ILIT booster, after three open label ILIT injections, can increase the allergen specific IgG4 antibodies, and if the IgG4 increase can be correlated to clinical effect characterized with seasonal questionnaires.

The first part of the study is completed and published (PMID: 23374268)

Inclusion Criteria:

• Age 18-50,
• Seasonal allergic symptoms for birch and/or grass verified by skin prick test,
• Accepted informed consent

Exclusion Criteria:

• Pregnancy or nursing
• Autoimmune or collagen disease (known)
• Cardiovascular disease
• Perennial pulmonary disease
• Hepatic disease
• Renal disease
• Cancer
• Any medication with a possible side-effect of interfering with the immune response
• Previous immuno- or chemotherapy
• Chronic diseases
• Other upper airway disease (non-allergic sinusitis, nasal polyps, chronic obstructive and restrictive lung disease)
• Disease or conditions rendering the treatment of anaphylactic reactions difficult (symptomatic coronary heart diseases, severe arterial hypertension and treatment with β-blockers)
• Major metabolic disease
• Known or suspected allergy to the study product
• Alcohol or drug abuse
• Mental incapability of coping with the study
• Withdrawal of informed consent