The number of successful injections associates with improved clinical effect in intralymphatic immunotherapy

To the Editor, Intralymphatic immunotherapy, ILIT, has emerged as a symptomreducing immune treatment of allergic rhinoconjunctivitis as most studies find significant efficacy.1,2 In ILIT, a dose of allergen 100-fold lower than in SCIT is injected into a lymph node. Precise injection may therefore be essential to give a clinical and immunological response. Conversely, allergic side effects may develop if the allergen is injected extra-nodally. In a multicenter trial (EudraCT 2014-004031-40), we studied the relationship between the number of successful ILIT injections and clinical response and adverse events to ILIT. One hundred and seventy five patients suffering from allergic rhinoconjunctivitis in the grass pollen season and with a positive skin prick test to grass pollen extract were included (Table S1). Three ILIT injections of 1.000 SQU of ALK Alutard, Phleum Pratense were given off label in 1-month intervals. Injections were performed by allergists undergoing a training program in ultrasound-guided lymph node