Genetic polymorphisms of ADRB2 and IL10 may be associated with the risk of IgE sensitization to digestive powders in exposed medical personnel.

BACKGROUND: It has been reported that pancreatic extracts may induce IgE-mediated respiratory allergy in medical personnel. The aim of the study was to identify genetic factors associated with IgE sensitization to digestive powders containing pancreatic extract. METHODS: This case-control study was performed on 153 subjects routinely exposed to digestive powder and on 123 nonexposed controls working in Ajou University Hospital. Skin prick testing was performed using 4 commonly used digestive powders and α-amylase. Serum specific IgE levels were measured by ELISA. Three single nucleotide polymorphisms, ADRB2 46A>G, IL10 -1082A>G and IL4 -589T>C, were genotyped using the single base extension method. RESULTS: The positive rate of serum specific IgE to digestive powder was significantly higher in the 41 (26.8%) exposed personnel with work-related respiratory symptoms than in controls (24.4 vs. 5.4%, p = 0.012). Thirty-nine (25.5%) of the 153 exposed personnel were found to have an allergy to digestive powder, as determined by a positive skin prick test and/or a high serum specific IgE level to digestive powder. The ADRB2 46A>G and IL10 -1082A>G polymorphisms were found to be significantly associated with the development of an allergy to digestive powder in exposed medical personnel by multiple logistic regression analysis after controlling for age, atopy and job type (pharmacist or nurse; p = 0.035 and p = 0.027, respectively). CONCLUSION: These results suggest that the genetic polymorphisms ADRB2 46A>G and IL10 -1082A>G are genetic factors that increase IgE sensitization to pancreatic extracts in medical personnel occupationally exposed to digestive powders.

Alpha amylase is a major allergenic component in occupational asthma patients caused by porcine pancreatic extract.

Porcine pancreatic extracts (PPE) are composed of alpha-amylase and lipase, which are common components of digestive enzymes. They have been known to cause occupational asthma in exposed workers in pharmaceutical and baking industries, as well as in a laboratory technician, but there has been no report of PPE-induced occupational asthma in medical personnel and their IgE binding components to each component. Four asthmatic subjects showing positive results on PPE-bronchoprovocation testing were enrolled. All of them were nurses working in a university hospital. Their job included grinding and mixing PPE powder for admitted patients. Serum-specific IgE antibodies to PPE, alpha-amylase, and lipase were measured by enzyme linked immunosorbent assay (ELISA). To confirm specificity of IgE binding and cross-allergenicity among the three extracts, ELISA inhibition tests were performed. In order to characterize allergenic components within these three extracts, SDS-PAGE and IgE immunoblot analysis were done. Specific IgE antibodies to PPE, alpha-amylase, and lipase were detectable by ELISA in all study subjects. An alpha-amylase ELISA inhibition test showed significant inhibitions by amylase and PPE, and minimal inhibition by lipase. However, a lipase ELISA inhibition test showed significant inhibitions by alpha-amylase and PPE with a lesser degree of inhibition by lipase. Furthermore, IgE immunoblot analysis showed one IgE binding component (55 kDa) within PPE, six components (55 kDa, 43 kDa, 41 kDa, 32 kDa, 31 kDa, 29 kDa) within alpha-amylase and two components (31 kDa, 29 kDa) within lipase extracts. Thesefindings suggest that inhalation of PPE powder can induce IgE-mediated bronchoconstriction in exposed nurses. Alpha-amylase is a major allergenic component within PPE.

Serum immunoglobulin G directed against porcine trypsin in the serum of cystic fibrosis children receiving porcine pancreatic enzyme supplements.

Cystic fibrosis (CF) patients require pancreatic enzyme replacement therapy to correct pancreatic insufficiency. These enzymes are derived from porcine pancreas and are known to be antigenic. To determine the possible clinical consequences, a specific ELISA was developed to detect IgG antibody directed against porcine trypsin (PTAb) in the sera of CF patients. The assay was used to evaluate the occurrence of PTAb in a cross sectional study of 103 CF patients in relation to the introduction of porcine enzyme therapy, clinical status and genotype. Antibodies against porcine trypsin were detected in the sera of 63% of patients unrelated to the age of commencement or the duration of enzyme therapy. No differences were observed in the clinical status of CF patients who had developed PTAb (n = 65) and those who had no detectable PTAb (n = 38) as determined from: the current prescribed dose of porcine pancreatic enzyme capsules; Z scores for height and weight; and respiratory function tests. It is suggested that the PTAb commonly found in the sera of CF patients are of doubtful clinical significance but the prospect of PTAb contributing to immune complex disease should be examined further.

Occupational allergy to pancreatic powder: characterization of IgE-binding antigens in pancreatic extract by immunoblotting.

The IgE response to inhaled dust of pancreatic powder was studied with sera from two employees of a pharmacy. IgE from both sera was directed against both porcine and bovine trypsin preparations. The major IgE-binding structures had an isoelectric point in the pH 8 to 9 range. The molecular weight of the IgE-binding structures was different for both patients. In one patient, most IgE was directed against a 28 to 30 kd structure, whereas the second patient had IgE directed against components with a molecular weight of 35 and 45 kd, respectively.

[Leucocyte migration inhibition test in diabetes mellitus (author's transl)].

The leucocyte migration inhibition test (LMT) using the agarose plate method introduced by Clausen is simple and highly reproducible. Using human pancreas extract and beef insulin as antigen, LMT was performed on ten patients with insulin dependent diabetes, twenty patients with insulin independent diabetes, and twelve healthy controls. The migration index was expressed as a percentage of migration calculated from the following formula. Migration index (MI) = average areas of migration in test suspension/average areas of migration in control suspension. Using human pancreas extract, the mean migration index for the insulin dependent diabetics (87.6 +/- 11.1) was significantly lower than in the normal subjects (99.3 +/- 6.3) (p less than 0.05). Using beef insulin as antigen for the insulin dependent diabetics and insulin independent diabetics, the mean migration indices (+/- SD) were 95.8 +/- 14.9 and 98.7 +/- 12.3 respectively. The corresponding values for the control group were 98.9 +/- 7.8. Cellular hypersensitivity to human pancreas extract was shown in the leucocyte migration inhibition test with insulin dependent diabetics, but a negative result was obtained with beef insulin.

Serum antibodies in human pancreatic disease.

An immunofluorescent study of sera from patients with various pancreatic diseases and from controls was carried out using human pancreas as substrate. A reproducible pattern of immunofluorscence, consisting of a coarse granular appearance in the cytoplasm of acinar cells of the pancreas and independent of the ABO blood group system was found. This occurred in 21 of 61 patients with acute pancreatitis; it was not found in other pancreatic diseases, and occurred in only four of 170 control subjects consisting of mixed hospital patients and healthy adults. Preliminary absorption experiments suggest that the antigen is located in the microsomal fraction of pancreatic homogenates and may be organ-specific. The relationship of positive antibody tests to aetiological factors is discussed.