Clinical efficacy and tolerance of two year Lolium perenne sublingual immunotherapy.

Last years, in spite of increasing use of sublingual immunotherapy (SLIT), not enough clinical studies have been published and its efficacy ought to be documented still more. For that purpose, 54 patients suffering seasonal rhinoconjunctivitis--with or without asthma--were allocated to either six month preseasonal SLIT with Lolium perenne extract (n = 35) or to a control group (n = 19). In the following year, thirty from previously treated patients and 12 from former control group, received a nine-month pre-coseasonal SLIT. Skin (SPT) and conjunctival (CPT) allergen response were monitorized several times along the study. Either seric antibodies or intraseasonal eosinophil cationic protein (ECP), as symptom, medication scores and peak nasal inspiratory flow (PNIF) were also assessed, fifty-five adverse reactions were recorded (0.7% doses), although only four required treatment. No main changes in CPT, SPT and antibodies were detected. Nevertheless, during the first pollen season, treated patients needed less medication than their control counterparts (p < 0.05). In the second season, the twelve ex-control subjects also required fewer drugs than in the first one (p < 0.01). Moreover, the whole forty-two treated patients showed a lesser intraseasonal ECP than a reference set of grass-allergic individuals (p < 0.05). We conclude that Lolium perenne SLIT is well tolerated and induces fewer drug requirements during pollen season, being eosinophil activation additionally reduced.