Percutaneous reactivity to natural rubber latex proteins persists in health-care workers following avoidance of natural rubber latex

BACKGROUND: Long-term avoidance of natural rubber latex [Hevea brasiliensis (Hev b)] is currently recommended for health-care workers (HCWs) with established natural rubber latex (NRL) allergy. Percutaneous sensitivity to eight Hev b NRL allergens was evaluated in HCWs in 2000. To date, no studies have evaluated the longitudinal effects of NRL avoidance on percutaneous sensitivity to NRL allergens. OBJECTIVE: The aims of this study were to evaluate changes in percutaneous reactivity to non-ammoniated latex (NAL) and NRL allergens in HCWs 5 years after a recommendation to avoid NRL and to evaluate factors that predict the persistence of in vivo sensitivity to NAL and NRL allergens. METHODS: Skin prick testing was performed with NAL, seven NRL allergens (Hev b 1, 2, 3, 4, 6.01, 7.01, and 13), and recombinant Hev b 5 (rHev b 5) in 34 HCWs who were initially evaluated in 2000 for occupationally related NRL allergy. Serial 10-fold dilutions of NAL and NRL allergens were employed in skin testing. Sera from the HCWs were assayed for latex and enhanced latex (rHev b 5-enriched allergosorbent)-specific IgE antibodies using the ImmunoCAP assay. RESULTS: The prevalence of work-related symptoms significantly decreased between 2000 and 2005 with avoidance of NRL (P<0.05). A >/=100-fold reduction in percutaneous sensitivity to Hev b 2 and Hev b 7 was less likely in those with prior history of systemic reactions to NRL (P=0.0053), reported history of reaction to cross-reactive foods (P=0.014), continued local reactions to NRL gloves (P<0.0001), or high NRL glove exposure since the initial study (P=0.0075). The diagnostic sensitivity and specificity of the latex-specific IgE serology was 54% and 87.5%, respectively, in comparison with NAL skin tests. The addition of rHev b 5 to the ImmunoCAP (enhanced latex) allergosorbent altered the diagnostic sensitivity and specificity of the ImmunoCAP to 77% and 75%, respectively. CONCLUSION: While symptoms may resolve quickly with NRL avoidance therapy, detectable IgE indicating continued sensitization remains beyond 5 years, and thus continued avoidance of NRL should be recommended.     

Outcome of a latex avoidance program in a high-risk population for latex allergy – a five-year follow-up study

BACKGROUND: Children with a shunted hydrocephalus are at highest risk for developing an immediate type allergy to latex. Limited data are available for preventive or therapeutical approaches. OBJECTIVE: To evaluate the effectiveness of latex avoidance, with special regard to status of sensitization and compliance. METHODS: In 1995, 131 children with a shunted hydrocephalus were screened for sensitization to latex by skin prick test and determination of specific IgE. Patients and parents were instructed on latex-avoiding strategies. Hospital physicians, family doctors and dentists were advised to perform further surgical and other medical interventions under latex-free conditions. In 2000, 100 of these 131 patients were re-evaluated according to the same testing procedures. Special attention was directed at the extent prophylaxis had been performed. RESULTS: In 1995, 30/100 patients re-evaluable in 2000 proved sensitized to latex, 70 had negative testing results. In 2000, 64/70 patients were still negative, six had meanwhile developed latex-specific IgE. Seven out of thirty subjects with former positive testing had changes within the same RAST-class, 20 showed a decline of at least one RAST-class, whereas in three cases an increase of latex-specific IgE was found. However, only 34 patients, mainly those being already sensitized, had thoroughly followed both medical and private prophylaxis. Within this group, 16 subjects (47.1%) had improved and another nine (26.5%) were still negative. Only three (8.8%) already previously sensitized patients presented with a further increase of latex-specific IgE. Medical prevention contributed more to the outcome than home prevention. No statistically significant correlation with latex-avoidance was observed, however, in previously unsensitized subjects. Underlying disease, atopy, number of operations, and age did not prove as significant variables. CONCLUSION: Secondary prevention results in a decrease of specific IgE in latex-sensitized patients with hydrocephalus. This is due to medical more than home prophylaxis. Sensitization obviously occurs mainly in early childhood, thus primary prevention remains to be the main target.     

Different latex aeroallergen size distributions between powdered surgical and examination gloves: significance for environmental avoidance

BACKGROUND: Proactive medical institutions implement latex allergen avoidance to protect workers and patients with latex allergy and to prevent latex sensitization in these groups by creating latex-safe environments that include replacement of natural rubber latex examination and surgical gloves, especially those that are powdered, with synthetic alternatives. We have hypothesized that an apparent decreasing trend in new latex allergy cases in hospitals using only synthetic examination gloves but the occasional powdered latex surgical glove might result from constitutive differences in allergen content (particle size distribution and quantity) between powdered surgical gloves and examination gloves. OBJECTIVE: Because aerodynamic particle size determines where inhaled airborne allergen deposits in the airway, the aim of this study was to investigate the differential particle size distribution of latex allergen released from powdered latex examination and surgical gloves. METHODS: Powdered and nonpowdered latex examination and surgical gloves were processed to create an aerosol in a glove box equipped with air sampling equipment capable of total particle number and mass measurements. Air particulate generated in the glove box was collected on impactors with less than 2.5-microm, 2.5- to 10-microm, and greater than 10-microm particle size limits (4 L/min for 4 hours). All filters were extracted, and latex allergen was quantified by using a latex-CAP inhibition assay with a human IgE anti-latex serum pool. RESULTS: Latex aeroallergen on powdered sterile surgical gloves resided primarily on particles greater than 10 microm in size (P <.006). In contrast, powdered examination gloves released the highest total latex aeroallergen content, with 68% of the particles sized in the respirable 2.5- to 10-microm range and carrying 56% of the airborne latex allergen. CONCLUSIONS: Significantly lower quantities and larger sizes of latex allergen-containing particles released from surgical gloves provides one potential explanation as to why an apparent decrease in new cases of latex allergy can occur in hospitals that successfully replace latex examination gloves with synthetic gloves but continue occasional use of powdered surgical gloves.     

Monoclonal antibody against a major latex allergen reacts with latex products and ammoniated natural latex

Spina bifida patients have been shown to be a high-risk group for latex allergy. Of the several latex proteins identified from nonammoniated natural latex, a polypeptide with a molecular mass of about 23 kDa was shown to be one of the major allergens reacting with IgE in the sera from such patients. Using hybridoma technology, a monoclonal antibody (mAb) 1E2 against the 23-kDa latex allergen was produced. The presence of the 23-kDa or related allergens in finished latex products was evaluated using 1E2. Of the 16 extracts of finished latex products, 12 reacted with 1E2. The other four products are not used in health care. Since the majority of latex products used in health care are manufactured from ammoniated latex and ammoniation may alter latex proteins, we also investigated the effect of ammoniation on the 23-kDa allergen. Although ammoniation degraded latex proteins, the 23-kDa antigen could still be detected by using mAb 1E2 on immunoblot of ammoniated latex proteins. Furthermore, ammoniation resulted in the appearance of additional proteins in high molecular weight positions not present in nonammoniated natural latex, which retained the 23-kDa epitope. The 23-kDa allergen could also be detected on surgical gloves after extensive washing.     

Natural latex 1991

After briefly reviewing quantities, qualities, origins, and applications of natural rubber latex, the economic aspects are considered from the point of view of a parallel between the price fluctuations of this commodity and the demands of medical-use gloves in the United States. Following the great boom in the market in 1987-1988, there has been a relative stabilization of the price of natural latex. The absolute necessity of using in Europe as well as in the United States rubber products that are truly hypoallergenic today and perhaps nonallergenic tomorrow requires that their quality be improved.     

A latex fixation test using British latex and bovine gamma globulin

A British polystyrene latex-bovine gamma globulin fixation test which can be used for serum titrations is described. It is technically easier to perform than the latex fixation test of Singer and Plotz (1956) and appears to be equally sensitive. There was agreement with a sensitized sheep cell agglutination test in 264 of 300 cases (88%).