Skin prick test and serological analysis with recombinant group 2 allergens of the dust mites L-destructor and T-putrescentiae

Background The dust mites Lepidoglyphus destructor and Tyrophagus putrescen tiae are important sources of allergen in farming environments. The major a llergens of the dust mites L. destructor and T. putrescentiae have been clo ned and expressed as recombinant proteins. Objective To evaluate the use of recombinant group 2 allergens of L. destru ctor (rLep d 2) and T. putrescentiae (rTyr p 2) in skin prick test (SPT), a nd serological analysis in sensitized and non-sensitized farmers chronicall y exposed to dust mites. Methods Skin prick test with rLep d 2, rTyr p 2 and the corresponding comme rcial extracts was performed in 44 farmers sensitized to L. destructor and/ or T. putrescentiae, and 38 control farmers. IgE and IgG subclass antibodie s to the recombinant allergens were analysed by RAST and ELISA, respectivel y. Results Out of the 44 subjects positive in SPT to L. destructor and/or T. p utrescentiae extract, 26 (59%) displayed a positive SPT to one or the other of the recombinant allergens, whereas 21 (48%) were positive to both. Sign ificant correlations were registered between the sizes of the weals induced by rLep d 2 and rTyr p 2 and the corresponding RAST values (P < 0.001). A majority of subjects positive in SPT to the recombinant allergens had detec table IgG4 antibodies, and the levels were significantly higher in the dust mite sensitized group than in the controls (P < 0.05). No such differences were found in the IgG1 values (P > 0.05). The results obtained with rLep d 2 and rTyr p 2 correlated relatively well with each other with respect to SPT, RAST and IgG4, suggesting that the allergens have similar or shared Ig E epitopes. All the control subjects had a negative SPT and RAST to rLep d 2 and rTyr p 2. Conclusion Recombinant group 2 allergens from the dust mite L. destructor a nd T. putrescentiae represent useful tools for diagnosis of dust mite aller gy.