Richard T. Jones

A prospective, controlled study showing that rubber gloves are the major contributor to latex aeroallergen levels in the operating room☆☆☆★★★

BACKGROUND Although protocols have been published for reducing natural rubber latex exposure in medical environments, there are no objective data documenting their effectiveness. OBJECTIVE We prospectively studied the impact of a single intervention, substitution of low-allergen-containing latex gloves for high-allergen-containing latex gloves, on latex aeroallergen levels in a single operating room (OR). METHODS We sampled OR air on 52 consecutive days, including 33 surgery days and 19 nonsurgery days. On each surgery day all personnel wore either high-allergen gloves (n = 18 days) or low-allergen gloves (n = 15 days). Latex aeroallergen levels (in nanograms per cubic meter) and extractable latex glove allergen contents (in allergen units per milliliter) were measured by inhibition immunoassays. An on-site study monitor recorded the number of gloves used, the total time spent by all patients in the OR each day (OR time), and the total time of all procedures for each day (operating procedure time). RESULTS Latex aeroallergen levels during low-allergen glove use days (mean, 1.1 ng/m3; median, 0.9 ng/m3; range, 0.1 to 3.5 ng/m3) were significantly lower than on high-allergen glove use days (mean, 13.7 ng/m3; median, 7.7 ng/m3; range, 2.2 to 56.4 ng/m3) (p < 0.001) but not significantly different from that on nonsurgery days (mean, 0.6 ng/m3; median, 0.3 ng/m3; range, 0.1 to 3.6 ng/m3). Latex aeroallergen levels were strongly correlated with the total number of gloves used on designated high-allergen glove days (r = 0.66, p = 0.003). There was no appreciable day-to-day carryover of latex aeroallergen. CONCLUSIONS The substitution of low-allergen-containing latex gloves for high-allergen-containing latex gloves can reduce levels of latex aeroallergen by more than 10-fold in an OR environment.

Immunoassay of peanut allergens in food-processing materials and finished foods*

To quantitate trace amounts of peanut allergens in food-processing materials and finished foods, we established a solid-phase radioimmunoassay inhibition using pooled sera from five peanut-sensitive subjects and a roasted peanut-meal extract covalently linked to polyacrylamide beads. Test samples were extracted, dialyzed, lyophilized, and reconstituted at 10 to 225 mg of dry weight per milliliter concentrations. The peanut-allergen content of test samples was expressed relative to a reference extract of roasted peanut meal that was assigned an arbitrary potency of 100,000 U/ml. In confectionery products spiked with varying quantities of peanut (0.7% to 0.0175%), the recovery of peanut allergen ranged from 31% to 94%. The sensitivity of the assay was 2.5 U/mg of dry weight from these samples (0.00875% peanut). Peanut allergens were undetectable in virgin vegetable oil used to roast peanuts, but 600 to 7600 U/mg of dry weight were present in oil after varying periods of use. The allergen content of used oil was reduced to 8 U/mg of dry weight by filtration and steam cleaning. The availability of such assays provides a means of monitoring finished food products for potential allergens. This monitoring in turn will provide the means to correlate symptoms experienced by sensitive patients with the exact quantity of allergen ingested. At the present time, there is little information on the quantities of ingested peanut allergen that pose risks to peanut-sensitive subjects.

Detection and quantitation of raw fish aeroallergens from an open-air fish market

BACKGROUND IgE-mediated hypersensitivity to fish is a clinically relevant problem, particularly in several European countries. Although most allergic reactions to fish are caused by ingestion, occupational exposures to seafood allergens by inhalation have been correlated with respiratory symptoms. In Madrid, patients with fish allergy have exhibited respiratory symptoms after visits to an open-air fish market. OBJECTIVE We sought to study the possibility of passively aerosolized fish allergen in an open-air fish market through air sampling and a competitive IgE immunoassay. METHODS Air samples were collected on polytetrafluoroethylene filters by using air samplers. Samples were collected on 41 different days from both an open-air fish market and an outdoor residential area. Fish allergens were specifically quantified by competitive IgE immunoassay by using pooled sera from fish-sensitive individuals. A raw fish extract (10 mg of dry weight/mL) was used as the reference standard. RESULTS Allergen was quantified in all 39 fish market air samples (2-25 ng/m(3)). The residential air samples contained no detectable allergen. The analytic limit of detection was 2 ng, allowing detection of 0.4 ng/m(3) for the air volumes collected. A concentrated (30-fold) pool of fish market air samples was tested in serial dilutions and demonstrated an identical regression line to that of the raw fish standard. CONCLUSION By using air sampling and an immunochemical analytic technique, fish allergen is detectable in the air of an open-air fish market. Avoidance of a food allergen, such as fish, should include preventing exposure to aerosolized particles through inhalation in relevant environments.

Inhalation challenge testing of latex-sensitive health care workers and the effectiveness of laminar flow HEPA–filtered helmets in reducing rhinoconjunctival and asthmatic reactions

BACKGROUND There are few data relating latex aeroallergen concentrations to biologic responses in latex-sensitized persons. OBJECTIVES We sought to investigate acceptable latex aeroallergen concentrations below which latex-sensitive health care workers do not experience symptoms and to study the effect of high-efficiency particle arrest (HEPA)-filtered laminar flow helmets in preventing latex-induced symptoms. METHODS Under challenge chamber conditions, latex-sensitive health care workers underwent 7 sequential inhalation challenge tests by donning and discarding either vinyl gloves (challenge 1), low latex-allergen powder-free gloves (challenge 2), or high latex-allergen powdered gloves (challenges 3 to 7) for up to 1 hour. Volunteers wore a laminar flow helmet during all challenges; HEPA filters in the helmet were in place only during challenges 3 and 4. Flow-volume loops, symptom scores, and latex aeroallergen concentrations were measured before and during each test. RESULTS At 60 minutes, latex aeroallergen concentrations during challenges 3 to 7 (mean, 7600 ng/m3; range, 93 to 54,000 ng/m3 ) were significantly higher than during challenges 1 or 2 (mean, 65 ng/m3; range, nondetectable to 100 ng/m3 ) (P <.001). During challenges 5 and 6, mean maximum percent falls in FEV1 (-16% and -11%, respectively) were significantly greater compared with those measured during challenges 3 and 4 (-3% and -1%, respectively) (P =.03). Mean maximum change from baseline symptom scores during challenges 5 and 6 was significantly higher than that during challenges 3 and 4 (P =.006). During challenges with high latex-allergen gloves, 4 volunteers had reproducible FEV1 falls of 20% or greater at cumulative inhaled latex aeroallergen doses ranging from less than 100 ng to 1500 ng. CONCLUSION The laminar flow helmets were effective in reducing latex-induced symptoms. Only 1 volunteer exhibited a fall in FEV1 of 20% or greater after a cumulative inhaled latex aeroallergen dose of less than 100 ng, and no volunteer showed a decline in FEV1 after exposure to powder-free low allergen gloves.

Biochemical and immunochemical comparison of Africanized and European honeybee venoms

Africanized honeybees (HBs) pose a hazard to both normal and sting-sensitive subjects in certain areas of Central and South America, and it is predicted that they will soon be present in the southern United States as well. Using an electrical stimulation device, we collected Africanized HB venom (AHV) in Venezuela and European HB venom (EHV) in Louisiana. These venoms, along with commercial European HB venom (CHV), were compared by thin-layer isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The Coomassie brilliant blue and silver-stained banding patterns of AHV and EHV were essentially identical to CHV. Western blots were prepared from SDS-PAGE gels and tested with pooled sera from EHV-sensitive subjects and then radiolabeled antihuman IgE. The resulting autoradiographs revealed similar banding patterns among EHV, AHV, and CHV. RAST-inhibition studies were performed with solid-phase CHV and pooled sera from EHV-sensitive subjects. The specific allergenic activities of the three HB venoms (allergy units per milligram of protein) were comparable. By RAST-inhibition assay with solid-phase, highly purified individual venom components, AHV and EHV both contained phospholipase A2, hyaluronidase, and high-molecular-weight allergens. The increased morbidity after Africanized HB stings is likely related to their more defensive behavior during which many bees react by stinging rather than to biochemical or allergenic differences between AHV and EHV.