Asthma in merchant seamen and laboratory workers caused by allergy to castor beans: analysis of allergens

Performance of specific immunoglobulin E tests for diagnosing occupational asthma: a systematic review and meta-analysis

OBJECTIVES

To determine the test performance parameters for the retrievable range of high-molecular-weight (HMW) and low-molecular-weight (LMW) occupational allergens and to evaluate the impact of allergenic components and the implementation of measures for test validation.

METHODS

A protocol with predefined objectives and inclusion criteria was the basis of an electronic literature search of MEDLINE and EMBASE (time period 1967-2016). The specific inhalation challenge and serial peak flow measurements were the reference standards for the specific IgE (sIgE) test parameters. All of the review procedures were reported according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

Seventy-one studies were selected, and 62 entered meta-analysis. Pooled pairs analysis indicated a sensitivity of 0.74(95% CI 0.66 to 0.80) and specificity of 0.71(95% CI 0.63 to 0.77) for HMW allergens and a sensitivity of 0.28(95% CI 0.18 to 0.40) and specificity of 0.89(95% CI 0.77 to 0.95) for LMW allergens. Component-specific analysis improved the test parameters for some allergens. Test validation was handled heterogeneously among studies.

CONCLUSION

sIgE test performance is rather satisfactory for a wide range of HMW allergens with the potential for component-specific approaches, whereas sensitivity for LMW allergens is considerably lower, indicating methodological complications and/or divergent pathomechanisms. A common standard for test validation is needed.

2: Final Report on the Safety Assessment of Glyceryl Ricinoleate

Glyceryl Ricinoleate is the monoester of glycerol and ricinoleic acid. Castor oil contains 87–90% Glycerol Ricinoleate. Ricinoleic acid is metabolized by both β-oxidation and α-oxidation.

Acute oral toxicity tests in mice indicated that Glyceryl Ricinoleate has an LD50greater than 25.0 ml/kg and is, at most, mildly irritating to unrinsed rabbit eyes. This ingredient was not a primary skin irritant.

Castor oil was nonmutagenic by the Ames test. Ricinoleic acid was not a carcinogen when tested in mice.

In human single-insult occlusive patch tests, no indication of skin irritation potential was observed in the two products containing 5.6% Glyceryl Ricinoleate.

The available data on Glyceryl Ricinoleate were insufficient to determine whether this ingredient, under each relevant condition of use, was either safe or not safe. The types of data required before a decision can be made include: (1) 28 day chronic dermal toxicity in guinea pigs, and (2) clinical sensitization and photosensitization studies (or an appropriate ultraviolet spectrum instead of the photosensitization data).

Characterization of the 11S globulin gene family in the castor plant Ricinus communis L

The 11S globulin (legumin) gene family has been characterized in the castor plant Ricinus communis L. Phylogenetic analysis reveals the presence of two diverged subfamilies (RcLEG1 and RcLEG2) comprising a total of nine genes and two putative pseudogenes. The expression of castor legumin genes has been studied, indicating that it is seed specific and developmentally regulated, with a maximum at the stage when cellular endosperm reaches its full expansion (around 40-45 DAP). However, conspicuous differences are appreciated in the expression timing of individual genes. A characterization of the 5'-proximal regulatory regions for two genes, RcLEG1-1 and RcLEG2-1, representative of the two legumin subfamilies, has also been performed by fusion to the GUS reporter gene. The results obtained from heterologous expression in tobacco and transient expression in castor, indicating seed-specific regulation, support the possible utility of these promoters for biotechnological purposes.

Temporal and spatial expression of 2S albumin in castor (Ricinus communis L.)

We studied the temporal and spatial expression of the 2S albumin in castor (Ricinus communis L.) during seed development, germination, post-germination, and plant development. Quantitative polymerase chain reaction analysis showed that the 2S albumin transcript accumulated to a maximum level at the middle of seed development, showing a bell-shaped temporal pattern. Residual levels of the transcript were present in the mature seed and degraded rapidly upon germination. Immunodetection analysis was performed using an anti-2S albumin antibody under reducing conditions. During seed development, the 2S albumin precursor pro-protein began to be synthesized at 26 days after pollination (DAP); the pro-protein was thereafter processed to mature proteins at 40 DAP, suggesting that the post-translation modification of 2S albumin takes place during this time period. Both the 2S albumin precursor pro-protein and the mature proteins accumulated throughout seed maturation and desiccation stages. During seed germination, both forms of the 2S albumin proteins were present in endosperm and cotyledon until the completion of germination and degraded rapidly afterwards. However, the antibody also detected a group of proteins/peptides in endosperm and cotyledon when the seeds progressed to germination and post-germination stages. A 14 kDa protein in the leaves of fully developed seedlings and mature plants also reacted to the anti-2S albumin antibody. The identity of the proteins accumulated in germinating seed and leaf remains unknown.

The effects of pollutants on the allergic immune response

An increase in the prevalence of allergy and allergic diseases has taken place in the industrialised countries. Allergic diseases represent a major health problem, and appear linked to affluence and modern lifestyle. In the 20th century air pollution from industrial sources largely has been replaced by diesel exhaust and other traffic pollution. Further, the indoor environment in which we spend most of our time has changed dramatically. In order to understand the contribution of pollution and other environmental changes to the development of allergy, we need to understand the biologic processes that underlie allergic immune responses. In the present paper, immune regulatory pathways that control the allergic immune response are delineated. Castor bean dust causes widespread allergic sensitisation. The investigations that made clear the importance of CD8 T cells for the regulation of IgE production were triggered by studies of castor bean allergy. A special focus is in this review placed on the regulatory role of CD8 T cells in the development of the allergic immune response.

Mechanisms of occupational asthma

BACKGROUND

The pathogenesis and the pathologic alterations of occupational asthma are similar to those of nonoccupational asthma. Occupational asthma may therefore represent a useful model of "human asthma" to investigate mechanisms and pathophysiology of asthma in general. In an occupational setting the cause and onset of asthma may be easily identified, and the natural history may be examined in follow-up studies. The mechanisms involved in occupational asthma include genetic predisposition, immunologically mediated responses, as well as nonspecific airway inflammation. In particular, high molecular weight (eg, grain dust, flour) and some low molecular weight sensitizers (eg, acid anhydrides and platinum halide salts) have been shown to induce occupational asthma through an immunoglobulin E (IgE)-dependent mechanism, while cell-dependent immunologic mechanisms are likely to be more relevant for occupational asthma induced by other low molecular weight sensitizers (eg, toluene diisocyanate and plicatic acid contained in western red cedar). The pathology of the airway mucosa of occupational asthma is remarkably similar to the pathology of nonoccupational asthma, ie, characterized by infiltration and accumulation of eosinophils, mast cells, and activated lymphocytes along with subepithelial fibrosis. In this article, the most relevant mechanisms are discussed with particular reference to the similarities and discrepancies between occupational and nonoccupational asthma.

Seasonal occupational asthma in an agricultural products merchant--a case report

A 52-year-old agricultural products merchant reported mild occupational asthma and rhinitis throughout the year, with severe asthma from February to May. He had been exposed to various substances, particularly grain, insecticides, fungicides, and fertilizers over 35 years. We identified a castor-bean-containing fertilizer as the cause of the disease by skin prick test and bronchial provocation test. Specific IgE against castor bean was detected by enzyme allergosorbent test, and proteins with mol. mass of less than 14.4 kDa and masses of 15.5, 29.5, and 30.5 kDa were identified as allergens by Western blot analysis. The seasonal character of symptoms could be explained by a more frequent use of the fertilizer during spring. Six months after avoidance of the allergen, the patient reported chronic bronchitis without asthma. Occupational allergy to castor bean should be considered in subjects with seasonal asthma and exposure to "natural" fertilizers.

Castor bean intoxication

We report the cases of a child who ingested two or more castor beans and two adults who each ingested four beans. All three patients developed severe gastroenteritis and recovered without sequelae after receiving IV fluids. The literature contains reports of 424 cases of castor bean intoxication. Symptoms of intoxication include acute gastroenteritis, fluid and electrolyte depletion, gastrointestinal bleeding, hemolysis, and hypoglycemia. Delayed cytotoxicity has not been reported. Of the 424 patients, 14 died (mortality rates: 8.1% of untreated and 0.4% of treated). Deaths were due to hypovolemic shock. Recommended treatment for asymptomatic patients who have chewed one or more raw beans is emergency department evaluation, gastric decontamination, administration of activated charcoal, observation until four to six hours after ingestion, and discharge instructions to return if symptoms develop. After decontamination and activated charcoal, symptomatic patients require hospitalization for treatment with IV fluids, supportive care, and monitoring for hypoglycemia, hemolysis, and complications of hypovolemia. Monitoring for delayed cytotoxicity is unnecessary. Castor beans and their dust are highly allergenic and may cause anaphylaxis.

Sensitization to green coffee bean (GCB) and castor bean (CB) allergens among dock workers

Dock workers (n = 218) occupationally exposed to green coffee beans (GCB) were studied, using a specific questionnaire for allergic symptoms and skin tests for common and occupational allergens. Thirty-one workers (14.3%) complained of allergic symptoms of the eye, nose and bronchial system at the workplace. The prick tests, using both commercial allergens and specific extracts prepared from the most common types of coffee and their corresponding sacks, confirmed a sensitization in 21 workers (9.6%). A positive skin reaction to castor beans (CB) was found in nearly all these cases; in ten workers there was also a positive reaction to GCB allergens and in 14 cases prick tests were positive to extracts of sacks. There was a good concordance between prick tests and specific IgE for CB (95.0%) and also, but to a lesser extent, for GCB. The authors concluded that there is a significant risk of sensitization to CB and GCB allergens in dock workers occupied in handling green coffee bean, despite the fact that the exposure is not continuous. CB emerged as a common contaminant of GCB from various countries. For effective prevention, a modification of the methods of transport is required to avoid CB contamination to other products. Eliminating environmental dust during shipping operations is the most important preventive measure and it can be achieved by the use of containers, as some exporting countries are already doing.

Results of skin test and RAST in allergy to a clinically potent allergen (castor bean)

In order to investigate once more the usefulness of the RAST procedure in the diagnosis of reaginic hypersensitivity, we studied a series of patients showing a well known sensitivity to castor bean, which is a potent antigen, and compared the results with those given by patients with no clinical allergy to this antigen as confirmed by negative skin testing. The latter group included patients with no contact, a remote contact or a close contact with castor bean. Castor bean allergy seems to be a good model in the testing of human reaginic hypersensitivity. We observed in the castor bean positive group of forty-one patients a 95% correlation between RAST positivity and skin test positivity with only two negative RAST scores, and in the castor bean negative group of ninety-four patients, a 97% correlation, with three RAST positive scores. For its specificity and its good sensibility (although lesser than skin testing), RAST can thus be recommended as a diagnostic tool as a complement to skin testing. Moreover, for potent allergens, RAST offers a risk-free diagnostic alternative.