House dust mite allergy in Calcutta, India: evaluation by RAST

A significantly elevated (above 300 U/mL) serum IgE level was found in 97 of 105 dust-sensitive asthmatic patients of Calcutta and the mean value (1002 +/- 614 U/mL) was significantly higher (P << .001) than the control sera. RAST results indicate a higher sensitivity (84.76%) to house dust and house dust mites (Dermatophagoides supp) either alone or in combination with each other. Among positive samples, 79.77%, 71.91%, and 88.76% showed the presence of allergen specific IgE antibodies against house dust (HD), D. pteronyssinus (DP), and D. farinae (DF) mite antigens, respectively. The study highlighted the superiority of D. farinae antigen as a potent allergen in house dust of Calcutta over others and the mites and house dust possibly had a common allergen. The present investigation indicates that RAST sensitivity was independent of age and sex of patients (P > .05). The frequency of RAST sensitivity was observed to be greater in patients suffering for longer durations.