Occupational sensitization to soy allergens in workers at a processing facility.

BACKGROUND: Exposure to soy antigens has been associated with asthma in community outbreaks and in some workplaces. Recently, 135 soy flake processing workers (SPWs) in a Tennessee facility were evaluated for immune reactivity to soy. Allergic sensitization to soy was common and was five times more prevalent than in health care worker controls (HCWs) with no known soy exposure. OBJECTIVE: To characterize sensitization to soy allergens in SPWs. METHODS: Sera that were positive to soy ImmunoCAP (n=27) were tested in IgE immunoblots. Wild-type (WT) and transgenic (TG) antigens were sequenced using nanoscale Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry (nanoUPLC MS/MS). IgE reactivity towards 5-enolpyruvylshikimate-3-phosphate synthase (CP4-EPSP), a protein found in TG soy, was additionally investigated. De-identified sera from 50 HCWs were used as a control. RESULTS: Immunoblotting of WT and TG soy flake extracts revealed IgE against multiple soy antigens with reactivity towards 48, 54, and 62 kDa bands being the most common. The prominent proteins that bound SPW IgE were identified by nanoUPLC MS/MS analysis to be the high molecular weight soybean storage proteins, ß-conglycinin (Gly m 5), and Glycinin (Gly m 6). No specific IgE reactivity could be detected to lower molecular weight soy allergens, Gly m 1 and Gly m 2, in soybean hull (SH) extracts. IgE reactivity was comparable between WT and TG extracts; however, IgE antibodies to CP4-EPSP could not be detected. CONCLUSIONS AND CLINICAL RELEVANCE: SPWs with specific IgE to soy reacted most commonly with higher molecular weight soybean storage proteins compared with the lower molecular weight SH allergens identified in community asthma studies. IgE reactivity was comparable between WT and TG soy extracts, while no IgE reactivity to CP4-EPSP was observed. High molecular weight soybean storage allergens, Gly m 5 and Gly m 6, may be respiratory sensitizers in occupational exposed SPWs.

Protection against bronchial asthma by CFTR delta F508 mutation: a heterozygote advantage in cystic fibrosis.

Cystic fibrosis (CF) is a multisystem autosomal recessive disorder caused by mutations of the cystic fibrosis transmembrane regulator (CFTR), a protein that regulates cyclic-AMP-mediated chloride conductance at the apical membrane of secretory epithelia. Mutations in the CFTR gene are common in many populations. In North America, 4-5% of the general population are heterozygous for a CFTR mutation. Although there are over 400 known CFTR mutations, a single mutation, a deletion of the phenylalanine at position 508 (delta F508) in exon 10, accounts for about 70% of all CF chromosomes worldwide. The reasons for the high frequency of the delta F508 CFTR allele--the selective advantage associated with CF heterozygosity--are unknown. Many physiological abnormalities have been observed in CF heterozygotes, although the clinical significance of these observations is unknown. Preliminary unpublished data and anecdotal information from CF families suggested that, remarkably, the delta F508 allele might protect heterozygotes against bronchial asthma prompted us to further investigate this possibility. Here we present evidence that the delta F508 CF allele protects against asthma in childhood and early adult life.

Adverse respiratory outcomes associated with occupational exposures at a soy processing plant.

This study aimed to characterise the relationship between adverse health outcomes and occupational risk factors among workers at a soy processing plant. A questionnaire, spirometry, methacholine challenge, immune testing and air sampling for dust and soy were offered. Prevalence ratios (PRs) of respiratory problems from comparisons with the US adult population were calculated. Soy-specific immunoglobulin (Ig)G and IgE among participants and healthcare worker controls were compared. Associations between health outcomes and potential explanatory variables were examined using logistic regression. 147 (52%) out of 281 employees, including 66 (70%) out of 94 production workers, participated. PRs were significantly elevated for wheeze, sinusitis, ever-asthma and current asthma. Participants had significantly higher mean concentrations of soy-specific IgG (97.9 mg·L(-1) versus 1.5 mg·L(-1)) and prevalence of soy-specific IgE (21% versus 4%) than controls. Participants with soy-specific IgE had three-fold greater odds of current asthma or asthma-like symptoms, and six-fold greater odds of work-related asthma-like symptoms; the latter additionally was associated with production work and higher peak dust exposures. Airways obstruction was associated with higher peak dust. Work-related sinusitis, nasal allergies and rash were associated with reported workplace mould exposure. Asthma and symptoms of asthma, but not other respiratory problems, were associated with immune reactivity to soy.

HIV as a chronic disease: implications for long-term care at an AIDS-dedicated skilled nursing facility.

OBJECTIVE: To describe the characteristics and outcomes of the first 3 years of admissions to a dedicated skilled nursing facility for people with acquired immunodeficiency syndrome (AIDS). METHODS: Systematic chart review of consecutive admissions to a 30-bed, AIDS-designated long-term care facility in New Haven, Connecticut, from October 1995 through December 1998. RESULTS: The facility has remained filled to 90% or more of its bed capacity since opening. Of 180 patients (representing 222 admissions), 69% were male; mean age was 41 years; 57% were injection drug users; 71% were admitted directly from a hospital. Leading reasons for admission were (1) the need for 24-hour nursing/medical supervision, (2) completion of acute medical treatment, and (3) terminal care. On admission, the median Karnofsky score was 40, and median CD4+ cell count was 24/mm3; 48% were diagnosed with serious neurologic disease, 44% with psychiatric illness; patients were receiving a median of 11 medications on admission. Of 202 completed admissions, 44% of patients died, 48% were discharged to the community, 8% were discharged to a hospital. Median length of stay was 59 days (range 1 to 1,353). Early (< or = 6 months) mortality was predicted by lower admission CD4+ count, impairments in activities of daily living, and the absence of a psychiatric history; long-term stay (> 6 months) was predicted by total number of admission medications, neurologic disease, and dementia. Comparison of admissions from 1995 to 1996 to those in 1997 to 1998 indicated significantly decreased mortality rates and increased prevalence of psychiatric illness between the two periods (P < .01). CONCLUSIONS: A dedicated skilled nursing facility for people with AIDS can fill an important service need for patients with advanced disease, acute convalescence, long-term care, and terminal care. The need for long-term care may continue to grow for patients who do not respond fully to current antiretroviral therapies and/or have significant neuropsychiatric comorbidities. This level of care may be increasingly important not only in reducing lengths of stay in the hospital, but also as a bridge to community-based residential options in the emerging chronic disease phase of the AIDS epidemic.