Methods: An aerobiological survey was performed with a personal Burkard volumetric sampler over a year in suburban area of West Bengal. The allergenic potential of the pollen was studied by skin prick tests (in vivo), IgE-enzyme-linked immunosorbent assay and IgE specific immunoblotting (in vitro) methods. Soluble pollen protein in PBS (pH 7.3) was fractionated in 0-20%, 20-50% and 50-85% using (NH4)2SO4 precipitation. The total protein resolved in 12% SDS-PAGE and IgE immunoblotting was done using sera from 5 patients. Cross-reactivity of CS pollen with other species of Cassia pollen was tested by using dot blot method and inhibition immunoblotting.
Results: Cassia sophera pollen grains were found to be prevalent in the air of suburban part of W.B from May to November. C. sophera pollen antigen caused marked skin sensitivity among 22.5% atopic populations. Total protein was resolved into 17 distinct bands in 12% SDS-PAGE and five were found to have shown positive IgE reactivity through IgE immunoblotting. CS pollen was found to be positively cross-reactive with Cassia occidentalis, C. fistula, C. tora, C. siamea.
Conclusions: 5 major protein components of Cassia sophera have shown sensitization to atopic patients and 2 of them have markedly shown allergenic cross reactivity with other species of Cassia pollen. This information can be helpful for immunotherapy treatment.