Upregulation of Calprotectin and Downregulation of Retinol Binding Protein in the Serum of Workers with Trichloroethylene‐induced Hypersensitivity Dermatitis

Changes in inflammatory factors in the Brown Norway rat model of food allergy

BACKGROUND

The role of serum S100A8/A9 in intestinal inflammation has been confirmed, and its role in food allergy is currently being investigated.

OBJECTIVE

To explore the levels of S100A8/A9 and inflammatory factors, including Toll-like receptors 4 (TLR4), Nuclear transcription factors (NF-κB) and Tumor necrosis factor α (TNF-α), in mild food allergies.

METHODS

Eighty 3-week-old male Brown Norway rats were used. Forty rats were randomly assigned to the ovalbumin-sensitized experimental group, while 40 rats were assigned to the normal saline sham-sensitized control group. Body weight and length and the levels of serum ovalbumin-specific IgE (OVA-IgE), histamine, Th1-associated and Th2-associated factors, S100A8/A9 and inflammation-associated cytokines were compared.

RESULTS

Through the evaluation of OVA-IgE level and Th1/Th2 balance in the experimental group, a successful IgE-mediated food allergy model was constructed. Compared with the control group, the experimental group had higher serum S100A8/A9 levels on days 21, 28, 35 and 42 (all P < 0.05); higher TLR4 levels on days 28, 35 and 42 (all P < 0.05); higher TNF-α levels on days 28, 35 and 42 (all P < 0.05); higher NF-κB levels on days 35 and 42 (all P < 0.05); and higher IL-1β and IL-6 levels on days 7 to 42 (all P < 0.05). Moreover, positive correlations were found between the serum levels of S100A8/A9 and inflammation-associated cytokines [TNF-α: r = 0.378, P = 0.039; IL-1β: r = 0.679, P = 0.000; IL-6: r = 0.590, P = 0.001].

CONCLUSION

S100A8/A9 and inflammatory-related factors, including TLR4, NF-κB, TNF-α, IL-6 and IL-1β, is closely related to food allergies. Moreover, immune and inflammatory factors interact with each other in food allergies, which may provide insight into food allergy causes and treatments.

Upregulation of calprotectin in mild IgE-mediated ovalbumin hypersensitivity

Calprotectin, also known as S100A8/A9, has been linked to gut inflammation caused by IgE-mediated food hypersensitivities, but the pathophysiologic abnormalities it causes remain to be determined. We created a mild food hypersensitivity model through oral gavage of ovalbumin in Norway brown rats without using immune adjuvant. Changes in the levels of calprotectin and inflammation-associated cytokines were then observed over time. We found that fecal calprotectin as well as jejunal and liver TLR4, TNF-α, NF-κB, IL-1β, and IL-6 were upregulated in hypersensitive rats. Additionally, the influence of calprotectin on CD4⁺ T and dendritic cells was observed by co-culturing CD4⁺ T cells with dendritic cells, which revealed a shift toward increased Th2 T cells in calprotectin-treated cultures. These results suggest that calprotectin, along with other inflammatory factors, promotes the inflammation seen in mild food allergy.

Follow-up assessment of two cases of trichloroethylene hypersensitivity syndrome: A case report

The present study aimed to explore the stability, curability and sequelae of cases of Trichloroethylene (TCE) Hypersensitivity Syndrome (THS), and to investigate the causal allergens of THS. Two cases of THS were followed-up in the current study; both cases were healing following glucocorticoid therapy and were discharged >10 weeks prior to follow-up. A questionnaire investigation, health examination and patch test were performed. Allergens of TCE and its metabolites, including chloral hydrate, trichloroethanol (TCOH) and trichloroacetic acid, were applied in the patch test; 4 controls were included. The two subjects were experiencing itching, pigmentation and xerosis of the skin, and had abnormal results in the ophthalmology Schirmer I test and tear break-up time. The body temperature, liver function, superficial lymph nodes, blood, urine routine and autoimmune antibodies of two subjects were shown to be normal, and no new rashes had appeared. All mass concentration of chloral hydrate and TCOH were positive; 5.0% trichloroacetic acid was weakly positive, 0.5% trichloroacetic acid and all mass concentration of TCE were negative. All patch tests were negative in the 4 control subjects. The results suggest that THS was stable following treatment with glucocorticoid therapy. Dry eye syndrome may continue as a sequelae of THS. The patch test demonstrated that the mechanism underlying THS is delayed-type hypersensitivity induced by TCE. In addition, as the hypersensitivity state in a THS rehabilitee could be sustained over a long period of time, it suggests that the metabolites of TCE, not TCE itself, are responsible for THS. Therefore, patients with THS should avoid contact with TCE and its metabolites, and avoid using hypnotic and anticonvulsive drugs containing chloral hydra as the primary ingredient.

Trichloroethylene Hypersensitivity Syndrome Is Potentially Mediated through Its Metabolite Chloral Hydrate

Background

We documented previously the entity of trichloroethylene (TCE) hypersensitivity syndrome (THS) in occupational workers.

Objectives

To identify the culprit causative compound, determine the type of hypersensitivity of THS, and establish a screening test for subjects at risk of THS.

Methods

TCE and its main metabolites chloral hydrate (CH), trichloroethanol (TCOH) and trichloroacetic acid (TCA) were used as allergens at different concentrations in skin patch tests. The study included 19 case subjects diagnosed with occupational THS, 22 control healthy workers exposed to TCE (exposure >12 weeks), and 20 validation new workers exposed to TCE for <12 weeks free of THS. All subjects were followed-up for 12 weeks after the patch test.

Results

The highest patch test positive rate in subjects with THS was for CH, followed by TCOH, TCA and TCE. The CH patch test positive rate was 100% irrespective of CH concentrations (15%, 10% and 5%). The TCOH patch test positive rate was concentration-dependent (89.5%, 73.7% and 52.6% for 5%, 0.5% and 0.05%, respectively). Lower patch test positive rates were noted for TCA and TCE. All patch tests (including four allergens) were all negative in each of the 22 control subjects. None of the subjects of the validation group had a positive 15% CH patch test.

Conclusions

Chloral hydrate seems to be the culprit causative compound of THS and type IV seems to be the major type of hypersensitivity of THS. The CH patch test could be potentially useful for screening workers at risk of THS.

Identification of serum biomarkers for occupational medicamentosa-like dermatitis induced by trichloroethylene using mass spectrometry

Occupational medicamentosa-like dermatitis induced by trichloroethylene (OMLDT) is an autoimmune disease and it has become a serious occupational health hazard. In the present study, we collected fasting blood samples from patients with OMLDT (n=18) and healthy volunteers (n=33) to explore serum peptidome patterns. Peptides in sera were purified using weak cation exchange magnetic beads (MB-WCX), and analyzed by matrix-assisted laser desorption ionization time-of-flight-mass spectrometry (MALDI-TOF-MS) and ClinProTools bioinformatics software. The intensities of thirty protein/peptide peaks were significantly different between the healthy control and OMLDT patients. A pattern of three peaks (m/z 2106.3, 2134.5, and 3263.67) was selected for supervised neural network (SNN) model building to separate the OMLDT patients from the healthy controls with a sensitivity of 95.5% and a specificity of 73.8%. Furthermore, two peptide peaks of m/z 4091.61 and 4281.69 were identified as fragments of ATP-binding cassette transporter family A member 12 (ABCA12), and cationic trypsinogen (PRRS1), respectively. Our findings not only show that specific proteomic fingerprints in the sera of OMLDT patients can be served as a differentiated tool of OMLDT patients with high sensitivity and high specificity, but also reveal the novel correlation between OMLDT with ABC transports and PRRS1, which will be of potential value for clinical and mechanistic studies of OMLDT.