The clinical and immunological effects of short-term preseasonal grass pollen immunotherapy in patients with allergic rhinitis sensitized to grass pollens

Subjects were randomized to receive active preseasonal short-term grass pollen allergoid immunotherapy or placebo using a double-blind method. The immunotherapy product was a preparation of extracts of six-grass pollens treated with formaldehyde to produce an allergoid and adsorbed onto aluminium hydroxide. It was supplied in two concentrations, 1000 therapeutic units (TU)/ml and 10000 TU/ml. Subcutaneous injections commenced before the onset of the pollen season with 0.1 ml of 1000 TU/ml in February 2010 and followed by an approximate doubling of the dose weekly up to 0.6 ml of 10000 TU/ml. The standard regimen comprised of seven injections, once weekly, for seven weeks. Dose adjustments were made according to individual tolerance. The highest grass pollen grains are recorded between April and August in Turkey. Due to different times of pollination of the members of the Gramineae family, Gramineae pollens are usually found in the air during the whole year except a few months in Turkey. We used 01 March - 01 September as the pollen period in this trial and followed up participants for six months after the administration of the last injection.