Development of time-resolved immunofluorometric assays for the detection of house dust mite-allergic IgE in human sera

Abstract

Dermatophagoides farinae and D. pteronyssinus are the prevalent house dust mites (HDM) in tropical countries and are associated with allergic diseases. This investigation developed a time- resolved immunofluorometric assay (TR-IFMA) for the first time to detect specific IgE antibody in patients with skin prick test positive to HDM but no detectable IgE by other means. Levels of IgE to natural and recombinant HDM allergens were measured by TR-IFMA in 50 HDM-allergic patients and 19 healthy participants compared to sandwich enzyme-linked immunosorbent assay (ELISA). A recombinant allergen, rDerf2, showed a 14 kDa band corresponding to broad range proteins of natural HDM.TR-IFMA showed sensitivity lower than 0.35 kUA/l. TR-IFMA employing three HDM antigens showed good correlations with sandwich ELISA at R2 0.93-0.96. TR-IFMA detected HDM IgE in 62, 62, 25 percent of allergic patient serum sample compared to 28, 32, and 22 percent detected by ELISA result using three HDM allergen. TR-IFMA also detected 26.3, 31.6, and 5.3 percent positive samples from 19 healthy participants while ELISA showed 0, 5.3, and 0 percents IgE positive samples. The use of rDerf2 as an HDM allergen for the assay was verified with no statistically different from other HDM allergens. TR-IFMA showed lower detection limit than ELISA and yielded higher sensitivity for serum of people with allergic symptoms with no detectable HDM IgE. It is anticipated that TR-IFMA for HDM-specific IgE detection will play an important role in future diagnosis of HDM allergy in clinical laboratories and for different research purposes

T cell responses to der f2 mite allergens in Thai allergic patients

“…We found levels of specific IgE antibody detected by Df extract were higher than those by recombinant Der f2 allergen in allergic patients. These results are consistent with report of Almedida et al [22] and Pipatchaipaisan, [2]. It is implied that specific IgE antibody could be related to natural allergen exposure, thus reflecting a normal consequence of immediate hypersensitivity reactions in allergic patients in vivo [22].…”

“…In the present study, we found only 37.5 % allergic patients presenting positive SPT to both mites (Df and Dp), while 62.5 % of allergic patients sensitized to a panel of aeroallergen. These results were similar to those of our previous studies carried out in another group of allergic patients from Police hospital in Bangkok [2], confirming that the high rate of this concurrent sensitization has certainly complicated the evaluation of the role of D. farinae and D. pteronyssinus in these patients, particularly in tropical and subtropical regions where both mites coexist. Owing to glycosylated antigens have been shown to play a crucial role in different pathologies, particularly in fungal infections and allergic diseases [20].…”

“…The mite has been ubiquitously found in common houses in Tropical and subtropical areas [1]. D. farinae has been recognized as important source of allergens associated with allergic diseases such as asthma, rhinitis, and atopic dermatitis [2]. Group 2 allergen (Der f2 from D. farinae) is products of single gene, but it shows frequent allelic variation affecting several amino acids.…”

Perbandingan Nilai Diagnostik Ige Spesifik Tungau Debu Rumah, Metode Elisa Dan Imunoblot Pada Rinitis Alergi

“…Penyebab hasil positif semu lainnya adalah karena keberadaan protein yang homolog antara Der.p dan Der.f yang keduanya berukuran sama antara 10 sampai 72 kDa. 23 Penelitian ini memiliki beberapa keterbatasan yaitu: dalam kajian ini tidak diperiksa uji provokasi hidung dan nasal specific IgE TDR Der.p untuk kepastian diagnosis RA TDR Der.p, pemeriksaan jumlah keseluruhan IgE, tingkat eosinofil dan leukosit dalam darah tidak dilakukan di kelompok pasien rinitis non-alergi dan non-infeksi.…”