Cockroaches are important components of house dust allergens. In spite of significant subject reactivity to cockroach extracts, the specific source of the allergen remains unclear.

This study was performed to identify the important allergens in German cockroach whole body (GWBE), egg (GEE) and fecal (GFE) extracts in Korean atopy, and to compare the reactivity of GWBE and GEE by Western blot inhibition.

Sera from 11 subjects with Korean atopy were used for sodium dodecil sulfate polyacrylamide gel elctrophoresis (SDS-PAGE) and Western blot analysis.

Allergenic fractions in German cockroach extracts were numerous and distributed throughout the wide range of molecular weights. The important allergens of GWBE, GFE and GEE were similar to each other by using SDS-PAGE and Western blot ysis. The aUergen bands at 55 kd showed the most significant reactivity; in GWBE, GFE and GEE 73%, 82%, 55%, respectively. Other bands exhibiting significant activity were the 67 kd band with 37%, 19% and 19%, the 64 kd band with 64%, 37% and 9% respectively. Furthermore, Western blot inhibition investigations revealed that either GWBE or GEE could almost completely inhibit the reactivity of the other extract.

This study confirms that the 55 kd allergen can be considered as the major allergen in Korean atopy and demonstrated that the GWBE and GEE antigens have identical IgE-binding sites.