Efficacy of mycophenolate mofetil in sarcoidosis

BACKGROUND

Immunosuppressive (IS) therapy is indicated to treat progressive sarcoidosis, but randomized controlled trials to guide physicians in the use of steroid sparing agents are lacking. The aim of this retrospective study was to examine the role of mycophenolate mofetil (MMF) as an alternative therapy in the treatment of sarcoidosis.

METHODS

A retrospective chart review of all patients who had been prescribed MMF between January 2008 and October 2011 was conducted. Patients with insufficient data or who had another IS therapy initiated concomitantly with MMF, including prednisone, were excluded. Physiological data obtained at the time MMF therapy was initiated as well as six and twelve months before and after therapy was extracted. Longitudinal analyses of the effect of MMF on changes in pulmonary function at MMF start, 6 months, 12 months pre and post MMF therapy were conducted.

RESULTS

37/76 patients met our inclusion/exclusion criteria. There were no statistically significant changes in PFT measurements pre and post MMF therapy. We did find a trend (p = 0.07) towards improvement in DLCO 12 months pre and post MMF in patients who were started on MMF due to intolerance to previous IS therapy compared to those who were unresponsive to their previous IS therapy. We also noted a reduction in prednisone dose in those treated with MMF.

CONCLUSION

MMF appears to offer no extra benefit to sarcoidosis patients unresponsive to previous steroid-sparing agents, but may be beneficial in patients intolerant to their previous steroid-sparing agent. Additional studies investigating the efficacy of MMF as the initial steroid-sparing agent are needed to further clarify the role of MMF in sarcoidosis.

Associations between radiographic findings and spirometry in a community exposed to Libby amphibole

BACKGROUND

Among asbestos-exposed individuals, abnormal spirometry is usually associated with parenchymal abnormalities or diffuse pleural thickening. Localised pleural thickening (LPT), the most common abnormality associated with asbestos exposure, is typically thought to be a marker of exposure with little clinical consequence. Our objective was to determine if abnormal spirometry is associated with LPT independent of other abnormalities, using data from community-based screening conducted in Libby, Montana.

METHODS

Subjects were a subset of screening participants comprising persons with interpretable spirometry and chest radiograph results (n=6475). Chest radiographs were independently evaluated by two or three B readers, and participants were classified by mutually exclusive categories of spirometry outcome: normal, restriction, obstruction or mixed defect.

RESULTS

Restrictive spirometry was strongly associated with parenchymal abnormalities (OR 2.9; 95% CI 1.4 to 6.0) and diffuse pleural thickening (OR 4.1; 95% CI 2.1 to 7.8). Controlling for the presence of these abnormalities as well as age, smoking status and other covariates, restrictive spirometry was also associated with LPT (OR 1.4; 95% CI 1.1 to 1.8). The risk of restrictive spirometric findings correlated with the severity of LPT.

CONCLUSIONS

In this large community-based screening cohort, restrictive spirometry is significantly associated with LPT, indicating that this abnormality may result in lung function impairment. Physicians treating patients exposed to Libby amphibole should be aware that LPT may have functional consequences.

CC chemokine receptor 5 gene polymorphisms in beryllium disease

CC chemokine receptor 5 (CCR5) is expressed on type-1 T-helper cells, which are involved in the pathogenesis of the granulomatous lung disease chronic beryllium disease (CBD). CCR5 gene (CCR5) polymorphisms are associated with sarcoidosis severity. The present study explores associations between CCR5 polymorphisms and CBD and its disease progression. Eight CCR5 polymorphisms were genotyped in CBD (n = 88), beryllium sensitisation (BeS; n = 86) and beryllium-exposed nondiseased controls (n = 173) using PCR with sequence-specific primers. Pulmonary function and bronchoalveolar lavage data were examined for associations with genotypes. There were no significant differences in genotype and allele frequency between CBD, BeS individuals and controls. In CBD, associations were found with decline in forced expiratory volume in 1 s and forced vital capacity and the CCR5 -3458 thymidine (T)T genotype (p<0.0001), and an increase in alveolar-arterial oxygen tension difference at rest (p = 0.003) and at maximum exercise (p = 0.01) and the -5663 adenine allele. Increased bronchoalveolar lavage lymphocyte numbers were associated with CCR5 -2459 guanine/-2135T (p = 0.01) only in the combined CBD and BeS group. This is the first study showing that CCR5 polymorphisms are associated with worsening pulmonary function over time in CBD, suggesting that CCR5 is important in the progression of pulmonary function in CBD. Further studies would be useful to clarify the mechanism whereby CCR5 polymorphisms affect progression of CBD.

Beryllium-induced TNF-alpha production is transcription-dependent in chronic beryllium disease

Beryllium (Be)-antigen presentation to Be-specific CD4(+) T cells from the lungs of patients with chronic beryllium disease (CBD) results in T cell proliferation and TNF-alpha secretion. We tested the hypothesis that Be-induced, CBD bronchoalveolar lavage (BAL) T cell, transcription-dependent, TNF-alpha secretion was accompanied by specific transcription factor upregulation. After 6 h of Be stimulation, CBD BAL cells produced a median of 883 pg/ml TNF-alpha (range, 608-1,275 pg/ml) versus 198 pg/ml (range, 116-245 pg/ml) by unstimulated cells. After 12 h CBD BAL cells produced a median of 2,963 pg/ml (range, 99-9,424 pg/ml) TNF-alpha versus 55 pg/ml (range, 0-454) by unstimulated cells. Using real-time RT-PCR, Be-stimulated TNF-alpha production at 6 h was preceded by a 5-fold increase in TNF-alpha pre-mRNA copy number:beta-actin copy number (Be median ratio 0.21; unstimulated median ratio 0.04). The median ratio of mature TNF-alpha mRNA:beta-actin mRNA was upregulated 1.4-fold (Be median ratio 0.17; unstimulated median ratio 0.12). Be exposure in the presence of the transcription inhibitor pentoxifylline (PTX) decreased CBD BAL cell TNF-alpha pre-mRNA levels > 60%, whereas treatment with the mRNA splicing inhibitor 2-aminopurine (2AP) decreased levels 40% relative to Be exposure alone. PTX treatment decreased mature TNF-alpha mRNA levels 50% while 2AP decreased levels > 80%, relative to Be exposure alone. Beryllium exposure specifically upregulated transcription factors AP-1 and NF-kappaB. The data suggest that Be exposure induces transcription-dependent TNF-alpha production, potentially due to upregulation of specific transcription factors.

Effect of cytological fixative and environmental conditions on nuclear morphometric characteristics of squamous epithelial cells in sputum

BACKGROUND

Sputum samples for lung cancer screening trials are typically collected at home into specimen containers prefilled with cytologic fixative. Collection, transit, and storage expose samples to environmental conditions that may introduce artifacts that could confound evaluation. We examined whether the type of cytological fixative and exposure to different environmental conditions introduces artifacts that affect cytological analysis.

METHODS

Sputum fixed in Saccomanno fluid (SAC), containing methyl, ethyl, and propyl alcohols and polyethylene glycol, or CytoRich Red solution (CRR), containing methyl and isopropyl alcohols and ethylene glycol, plus formaldehyde, was aliquoted and exposed for 8 h to the following conditions: (a) -20 degrees C freezer, (b) 60 degrees C oven, (3) direct sunlight, and (4) room temperature. Cell morphometry was evaluated using computer-assisted image analysis (CAIA).

RESULTS

The values obtained for CAIA analysis of sputum were affected by the type of fixative used. Temperature extremes and sunlight dramatically altered nuclear morphometry of SAC-fixed cells. Artifacts were not observed in CRR-fixed cells.

CONCLUSIONS

The effects of environmental exposures were minimized if sputum was placed in a formalin-containing fixative such as CRR. If an alcohol-based fixative such as SAC is used, sample handling, transport, and storage must be monitored to prevent the introduction of artifacts.

Beryllium-Induced Tumor Necrosis Factor-α Production by CD4+T Cells Is Mediated by HLA-DP

Beryllium (Be) presentation to CD4+ T cells from patients with chronic beryllium disease (CBD) results in T cell activation, and these Be-specific CD4+ T cells undergo clonal proliferation and T-helper 1-type cytokine production. In exposed workers, genetic susceptibility to this granulomatous disorder is associated with particular HLA-DPB1 alleles. We hypothesized that these HLA-DP molecules could mediate Be-stimulated tumor necrosis factor-alpha (TNF-alpha) messenger RNA (mRNA) and protein production. Using intracellular cytokine staining, we found that treatment with an anti-HLA-DP, but not anti-HLA-DR, monoclonal antibody inhibited Be-stimulated TNF-alpha expression in lung CD3+ CD4+ T cells. This monoclonal antibody also blocked Be-specific T cell proliferation, increased production of TNF-alpha mature-mRNA transcripts, and increased TNF-alpha protein production by Be-stimulated CBD peripheral blood mononuclear cells and bronchoalveolar lavage (BAL) cells. The Be-stimulated upregulation of TNF-alpha mature-mRNA levels with TNF-alpha protein production was a unique property of CBD BAL cells, and did not occur in BAL cells from Be-sensitized patients without CBD, or sarcoidosis BAL cells. This study identifies HLA-DP as a regulatory component in the activation of T cell receptors on Be-specific CD4+ T cells from CBD patients resulting in proliferation and proinflammatory cytokine production.

Using Nuclear Morphometry to Discriminate the Tumorigenic Potential of Cells: A Comparison of Statistical Methods

Despite interest in the use of nuclear morphometry for cancer diagnosis and prognosis as well as to monitor changes in cancer risk, no generally accepted statistical method has emerged for the analysis of these data. To evaluate different statistical approaches, Feulgen-stained nuclei from a human lung epithelial cell line, BEAS-2B, and a human lung adenocarcinoma (non-small cell) cancer cell line, NCI-H522, were subjected to morphometric analysis using a CAS-200 imaging system. The morphometric characteristics of these two cell lines differed significantly. Therefore, we proceeded to address the question of which statistical approach was most effective in classifying individual cells into the cell lines from which they were derived. The statistical techniques evaluated ranged from simple, traditional, parametric approaches to newer machine learning techniques. The multivariate techniques were compared based on a systematic cross-validation approach using 10 fixed partitions of the data to compute the misclassification rate for each method. For comparisons across cell lines at the level of each morphometric feature, we found little to distinguish nonparametric from parametric approaches. Among the linear models applied, logistic regression had the highest percentage of correct classifications; among the nonlinear and nonparametric methods applied, the Classification and Regression Trees model provided the highest percentage of correct classifications. Classification and Regression Trees has appealing characteristics: there are no assumptions about the distribution of the variables to be used, there is no need to specify which interactions to test, and there is no difficulty in handling complex, high-dimensional data sets containing mixed data types.

Using nuclear morphometry to discriminate the tumorigenic potential of cells: a comparison of statistical methods

Despite interest in the use of nuclear morphometry for cancer diagnosis and prognosis as well as to monitor changes in cancer risk, no generally accepted statistical method has emerged for the analysis of these data. To evaluate different statistical approaches, Feulgen-stained nuclei from a human lung epithelial cell line, BEAS-2B, and a human lung adenocarcinoma (non-small cell) cancer cell line, NCI-H522, were subjected to morphometric analysis using a CAS-200 imaging system. The morphometric characteristics of these two cell lines differed significantly. Therefore, we proceeded to address the question of which statistical approach was most effective in classifying individual cells into the cell lines from which they were derived. The statistical techniques evaluated ranged from simple, traditional, parametric approaches to newer machine learning techniques. The multivariate techniques were compared based on a systematic cross-validation approach using 10 fixed partitions of the data to compute the misclassification rate for each method. For comparisons across cell lines at the level of each morphometric feature, we found little to distinguish nonparametric from parametric approaches. Among the linear models applied, logistic regression had the highest percentage of correct classifications; among the nonlinear and nonparametric methods applied, the Classification and Regression Trees model provided the highest percentage of correct classifications. Classification and Regression Trees has appealing characteristics: there are no assumptions about the distribution of the variables to be used, there is no need to specify which interactions to test, and there is no difficulty in handling complex, high-dimensional data sets containing mixed data types.

Occupational and environmental thoracic malignancies

Lung cancer is the most common thoracic malignancy caused by exposures at work and in the environment. The most unique thoracic malignancy is mesothelioma, because it is relatively rare and one of only a few neoplasms for which one specific inciting agent-asbestos-has been identified. Based on epidemiologic studies, approximately 15% of lung cancers in men and 5% of lung cancers in women are caused by occupational exposures. The International Agency for Research on Cancer has devised a rating system by which, based on animal and human data, they assign an agent, mixture, or exposure circumstance to one of five categories, ranging from group 1 (agent is carcinogenic to humans) to group 4 (agent is probably not carcinogenic to humans). Group 1 pulmonary carcinogens reviewed in this article include arsenic, asbestos, beryllium, bis (chloromethyl) ether, cadmium, chromium (IV), mustard gas, nickel, radon, and silica. The clinical presentation and pathology of lung cancers and mesothelioma caused by such exposures do not differ from those of cancers caused by other factors. The key to the recognition of a thoracic malignancy caused by workplace or environmental exposures is clinical suspicion and consideration of all causes for the disease present. Recognition of an exposure-related case of lung cancer or mesothelioma can aid in the identification of excess risk for a whole workforce or community and can lead to actions to reduce exposure, thus preventing future cases. In addition, such recognition allows the individuals struck by devastating illness to exercise their legal rights to compensation if so desired.

Almitrine mimics hypoxic vasoconstriction in isolated rat lungs

The effect of almitrine bimesylate or the solvent malic acid on pulmonary vascular perfusion pressure was assessed in isolated rat lungs and on the contractile behavior of rat aorta and main pulmonary artery rings. Addition of almitrine to the lung perfusate during normoxia caused a dose-dependent, transient increase in pulmonary artery pressure with no change of the lung microvascular pressure. In systemic or pulmonary conduit arteries, the contractile tension was unaffected by almitrine. This indicates a precapillary locus of drug action. We also examined almitrine's effect on hypoxic pulmonary vasoconstriction (HPVC) in isolated lungs perfused with blood or with physiological salt solution (PSS). Low-dose almitrine potentiated hypoxic vasoconstriction in blood- but not in PSS-perfused lungs. However, a high dose of almitrine reduced hypoxic vasoconstriction dose dependently. When almitrine was added to the lung perfusate during hypoxia- or cyanide-induced (NaCN, 5 x 10(-5) M) pulmonary vasoconstriction, almitrine caused no further vasoconstriction. However, when the pulmonary perfusion pressure was elevated by KCl (20 mM) to the same magnitude as by alveolar hypoxia or cyanide, almitrine elicited a pressor response comparable to that observed during normoxia. Almitrine-induced pulmonary vasoconstriction resembled hypoxic vasoconstriction in that agents known to enhance hypoxic vasoconstriction (phorbol myristate acetate, vanadate, and 4-aminopyridine) enhanced, and known inhibitors of HPVC (the Ca2+ entry blocker nifedipine and hypothermia) inhibited, the almitrine-induced vasoconstriction. These findings lead us to speculate that almitrine also affects the oxygen-sensing limb of the hypoxic pressor response, not simply the effector (contractile apparatus of the vascular muscle cell).