A study of natural rubber latex allergens in gloves used by healthcare workers in Singapore

Background Allergy to natural rubber latex (NRL) proteins is a well-recognized health problem among subjects using protective gloves and products made of NRL. There is currently no information on NRL allergen levels in gloves used in Singapore. Objectives This study aims to quantify the amount of specific allergens (Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02) found in rubber gloves used in Singapore. It also aims to determine if these levels are above thresholds that may cause NRL allergy. It also compares the levels of these specific allergens in gloves used for different purposes, namely gloves used for examination purposes or for surgical procedures. Methods Forty-nine rubber gloves were obtained from major hospitals and healthcare departments in Singapore and were analysed for their NRL allergen levels. FITkit(TM), based on the enzyme immunometric assay technique, was used to determine the specific allergen levels of Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 in the gloves. Results Examination gloves had higher NRL allergen content compared with surgical gloves, and powdered gloves had higher allergen content compared with nonpowdered gloves. Among the various allergens, Hev b 5 and Hev b 6.02 were present in larger quantities than Hev b 1 and Hev b 3. Only two of 19 (11%) surgical gloves had the sum of the four allergens (Hev b 1, Hev b 3, Hev b 5, Hev b 6.02) in excess of 1 mu g g(-1), which is believed to be a clinically relevant threshold. Among the examination gloves, 25 of 30 (83%) exceeded this level. Conclusions This study shows that NRL allergen levels are present in the majority of examination gloves used by healthcare workers in Singapore at levels high enough to cause NRL allergy among sensitized persons. The information can serve as evidence for a possible requirement for manufacturers to produce gloves with low NRL allergen levels and to state the allergen level in gloves in the product information.