Anti-p-benzoquinone antibody level as a prospective biomarker to identify smokers at risk for COPD.

BACKGROUND AND OBJECTIVE: Identification of smokers having predisposition to COPD is important for early intervention to reduce the huge global burden of the disease. Using a guinea pig model, we have shown that p-benzoquinone (p-BQ) derived from cigarette smoke (CS) in the lung is a causative factor for CS-induced emphysema. p-BQ is also derived from CS in smokers and it elicits the production of anti-p-BQ antibody in humans. We therefore hypothesized that anti-p-BQ antibody might have a protective role against COPD and could be used as a predictive biomarker for COPD in smokers. The objective of this study was to compare the serum anti-p-BQ antibody level between smokers with and without COPD for the evaluation of the hypothesis. METHODS: Serum anti-p-BQ antibody concentrations of current male smokers with (n=227) or without (n=308) COPD were measured by an indirect enzyme-linked immunoabsorbent assay (ELISA) developed in our laboratory. COPD was diagnosed by spirometry according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. RESULTS AND DISCUSSION: A significant difference was observed in the serum anti-p-BQ antibody level between smokers with and without COPD (Mann-Whitney U-test =4,632.5, P=0.000). Receiver operating characteristic (ROC) curve analysis indicated that the ELISA had significant precision (area under the curve [AUC] =0.934, 95% confidence interval [CI]: 0.913-0.935) for identifying smokers with COPD from their low antibody level. The antibody cutoff value of 29.4 mg/dL was constructed from the ROC coordinates to estimate the risk for COPD in smokers. While 90.3% of smokers with COPD had a low antibody value (≤29.4 mg/dL), the majority (86.4%) of smokers without COPD had a high antibody value (≤29.4 mg/dL); 13.6% of current smokers without COPD having an antibody level below this cutoff value (odds ratio [OR] =59.3, 95% CI: 34.15-101.99) were considered to be at risk for COPD. CONCLUSION AND FUTURE DIRECTIONS: Our results indicate that serum anti-p-BQ antibody level may be used as a biomarker to identify asymptomatic smokers at risk for COPD for early intervention of the disease.

Development of LLNA:DAE: a new local lymph node assay that includes the elicitation phase, discriminates borderline-positive chemicals, and is useful for cross-sensitization testing.

We developed a new local lymph node assay (LLNA) that includes the elicitation phase termed LLNA:DAE for discrimination of borderline-positive chemicals as classified by the LLNA modified by Daicel based on ATP content (LLNA:DA) and for cross-sensitization testing. Although the LLNA:DA method could help identify skin sensitizers, some skin irritants classified as non-sensitizers by the LLNA were classified as borderline positive. In addition, the evaluation for the cross-sensitization potential between chemicals was impossible. In the LLNA:DAE procedure, test group of mice received four applications of chemicals on the dorsum of the right ear for induction and one application on the dorsum of the left ear for elicitation. Control group of mice received one chemical application on the dorsum of the left ear. We evaluated the sensitizing potential by comparing the weights of the lymph nodes from the left ears between the two groups. The results of using the LLNA:DAE method to examine 24 chemicals, which contained borderline-positive chemicals, were consistent with those from the LLNA method, except for nickel chloride (NiCl2). Two chemical pairs, 2,4-dinitrochlorobenzene (DNCB) with 2,4-dinitrofluorobenzene (DNFB) and hydroquinone (HQ) with p-benzoquinone (p-BQ), showed clear cross-sensitization with each other, while another chemical pair, DNFB with hexylcinnamic aldehyde (HCA) did not. Taken together, our results suggest that the LLNA:DAE method is useful for discriminating borderline-positive chemicals and for determining chemical cross-sensitization.

Heat shock protein 90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin enhances EphA2+ tumor cell recognition by specific CD8+ T cells.

EphA2, a member of the receptor tyrosine kinase family, is commonly expressed by a broad range of cancer types, where its level of (over)expression correlates with poor clinical outcome. Because tumor cell expressed EphA2 is a nonmutated "self" protein, specific CD8(+) T cells are subject to self-tolerance mechanisms and typically exhibit only moderate-to-low functional avidity, rendering them marginally competent to recognize EphA2(+) tumor cells in vitro or in vivo. We have recently reported that the ability of specific CD8(+) T cells to recognize EphA2(+) tumor cells can be augmented after the cancer cells are pretreated with EphA2 agonists that promote proteasomal degradation and up-regulated expression of EphA2/class I complexes on the tumor cell membrane. In the current study, we show that treatment of EphA2(+) tumor cells with the irreversible heat shock protein 90 inhibitor, 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG), similarly enhances their recognition by EphA2-specific CD8(+) T-cell lines and clones in vitro via a mechanism that is dependent on proteasome and transporter-associated protein function as well as the retrotranslocation of EphA2 into the tumor cytoplasm. When 17-DMAG and agonist anti-EphA2 monoclonal antibodies are coapplied, T-cell recognition of tumor cells is further increased over that observed for either agent alone. These studies suggest that EphA2 represents a novel heat shock protein 90 client protein and that the treatment of cancer patients with 17-DMAG-based "pulse" therapy may improve the antitumor efficacy of CD8(+) T effector cells reactive against EphA2-derived epitopes.

Specific immune responses in workers exposed to benzene.

UNLABELLED: The aim of this study was to elaborate a method for detection of specific IgG antibodies (Abs) to the haptenes p-benzoquinone (p-BQ) and hydroquinone (HQ) for assessment of specific humoral immune responses. Plasma and urine, collected from petrochemical plant workers have been analyzed. The workers were divided into three professional groups in ascending order of benzene exposure. The concentration of benzene in the air was determined by gas chromatography with mass-spectrometry and trans,trans-muconic acid (biomarker of benzene exposure) in urine-by liquid chromatography with UV-detection. Specific IgG Abs to haptenes p-BQ and HQ in plasma were determined with newly developed ELISA. The relationships "exposure-effect," revealed increased levels of specific IgG to haptens correlating with the benzene exposure. The "exposure-response" relationships demonstrated that workers with value of OD over X+2SD were 62% low exposure group, 68% in group with level of exposure on Threshold Limit Value (TLV) and 91% in the highest exposure group. The data obtained show that there is a good correlation between antibody production and the biomarker of exposure t,t-muconic acid. CONCLUSION: The newly developed method is applicable for assessment of specific humoral immune responses in workers exposed to benzene. There was a good correlation between benzene exposure and formation of antibodies against benzene metabolites.

Lipoxygenase inhibitor-provoked acute asthma in a patient with asthma relieved by aspirin.

BACKGROUND: A very small number of patients with asthma show symptomatic improvement after administration of aspirin and other cyclooxygenase inhibitors. The clinical features of such patients with so-called aspirin-relieved asthma are similar to those with aspirin-induced asthma, but the pathogenesis is unclear. METHODS: We encountered one confirmed aspirin-relieved asthma patient and investigated the effects of cyclooxygenase and lipoxygenase inhibitors on his condition. RESULTS: Our patient showed a marked improvement of the forced expiratory volume in one second (FEV1) after administration of aspirin and three other cyclooxygenase inhibitors (indomethacin, mefenamic acid, and ketoprofen). A 5-lipoxygenase inhibitor (AA861, Takeda, Japan), however, evoked acute asthma, and repeated administration of this drug resulted in some desensitization, but not complete tolerance. CONCLUSIONS: These results suggest an altered balance of arachidonic acid metabolism may play a critical role in the pathophysiology of aspirin-relieved asthma.

[Primula eczema--well-known and overlooked]. / Primulaeksem--velkendt og overset.

A case of primula dermatitis presenting as recurrent hand eczema is reported. In spite of a positive patch test reaction to primin, the diagnosis was not made until three years later, when the patient was shown a colour photo of Primula obconica and admitted contact with the plant. Since few patients are able to supply correct information of exposure to this primula species, it is recommended to show colour photos of the plant as a routine procedure in cases where there are positive patch test reactions to primin.

Dissociation of allergenic and immunogenic functions in contact sensitivity to para-phenylenediamine.

Contact sensitivity to para-phenylenediamine (PPD) is a frequent delayed-type hypersensitivity resulting in contact dermatitis. The aim of the present study, conducted in 16 patients allergic to PPD (as assessed by a positive patch test), was to get better insight into the mechanism of T-cell activation in PPD contact sensitivity. PPD was unable to induce significant proliferation of T cells from a first set of 9 patients. In 7 further patients, lymphocyte proliferation was assessed using PPD and 2 PPD metabolites, namely Brandrowski's base (BB) and benzoquinone (BQ). BB specifically stimulated T-cell proliferation in a dose-dependent fashion in all 7 patients whereas BQ, like PPD, was ineffective. The peripheral blood mononuclear cells (PBMC) of 8 PPD nonallergic individuals did not respond to either PPD, BB or BQ. We concluded from this study that: (1) the immunogenic hapten in PPD hypersensitivity is not PPD itself, and (2) BB might be the oxidative derivative of PPD endowed with T-cell-activating properties. Further support to this statement was provided by the observation that a T cell line derived from PBMC of a PPD-allergic patient in the presence of PPD responded to BB but not to PPD. Our in vitro results suggest that PPD is a prohapten which when applied on the skin is metabolized and converted into products (such as BB) which are the immunogenic haptens able to activate specific T cells.

Study on cross-reactivity to the para group.

In 80 patients, positive to at least one hapten of the para group (para-phenylenediamine, diaminodiphenylmethane, benzocaine, PPD mix), patch tests were carried out with freshly prepared solutions of para-phenylenediamine (PPD) and of 3 selected aromatic compounds related structurally to PPD (para-aminophenol, ortho-aminophenol, hydroquinone). The number of positive reactions correlated with the rate of decomposition of the substances as evaluated by high-pressure liquid chromatography. PPD, which was almost decomposed after 24 h, gave the highest number of positive reactions, followed by ortho-aminophenol and by para-aminophenol, while hydroquinone, which was oxidized to the extent of 35%, did not give any reactions. To evaluate if a different rate of oxidation can modify the patch test response, in the same patients and in 10 normal volunteers, tests were carried out with PPD solutions containing the oxidizing agent silver oxide (0.1%). By this procedure a significant increase in the number of positive responses was observed. The results suggest that the rate of decomposition and therefore the amount of quinone(s) generated, might be the key to eliciting patch test responses to oxidizable aromatic haptens.