Evidence Suggesting the End of Universal Domestic Asbestos Exposure in Metsovo, NW Greece.

BACKGROUND: Inhabitants of Metsovo, NW Greece, had been domestically exposed to asbestos from a gradually abandoned whitewash ("luto") that resulted in a declining epidemic of malignant mesothelioma. OBJECTIVES: We aimed to evaluate whether other sources of asbestos exposure exist following "luto" abandonment. METHODS: Chest computed tomography (CT) and bronchoalveolar lavage (BAL) were used to evaluate residual asbestos exposure in younger Metsovites through the identification of pleural calcifications and asbestos bodies, respectively. In order to provide a historical universally exposed group for comparison, we used the accumulated chest CTs and chest roentgenograms of our previous studies, performed in Metsovites with confirmed exposure but negative chest roentgenogram. As an additional external comparison group, we also assessed CT scans and chest roentgenograms of Metsovites being older than our target group obtained from the records of the Radiology Department between 2009 and 2011. In order to be able to compare our BAL findings, we sought historical controls among BAL studies performed in Metsovites with known exposure to "luto," in the 1980s-1990s, mainly to evaluate alveolitis. Those belonging to individuals of the same age range were used for further comparison. RESULTS: Twenty-two Metsovites born between 1960 and 1980 consented to undergo a chest CT scan, while another 14 CTs were retrieved from the records of the Radiology Department (among 86 of all ages), thus increasing the number of individuals studied to 36. Five of the 36 Metsovites studied were former "luto" users for a short period of time. Minimal pleural calcifications were present in 2 of them, while all chest CTs of nonusers were negative. All 8 BAL studies were negative for asbestos bodies. CONCLUSION: "Luto" use seems to have been the only source of considerable asbestos exposure in Metsovo.

Use of interferon-gamma release assay for latent tuberculosis infection screening in older adults exposed to tuberculosis in a nursing home.

OBJECTIVES: To assess the additive value of a newly marketed interferon-gamma release assay, QuantiFERON-TB Gold In-Tube (QFT-GIT), to a single tuberculin skin test (TST) for the detection of latent tuberculosis infection (LTBI) in older adults who have been exposed to TB in a nursing home. DESIGN: Contact tracing included clinical examination, chest radiography, TST, and QFT-GIT in TST-negative people (TST< 5 mm). SETTING: A private nursing home. PARTICIPANTS: Seventy-seven individuals (63 elderly residents, 14 young employees) who had been exposed to an active TB case in a private nursing home. MEASUREMENTS: Comparison of TST and QFT-GIT in older adults who have been exposed to TB. RESULTS: For the TST, the positive response rate was 31.7% (n=20) of elderly residents and 43% (n=6) of staff. Positive QFT-GIT results were obtained in seven (16.3%) elderly residents with negative TST, six of whom were aged 80 and older. QFT-GIT increased the percentage of possible LTBI in this group from 31.7% to 42.9%. CONCLUSION: QFT-GIT has a significant additive value to single TST for detecting LTBI in institutionalized older adults, identifying infected subjects anergic to the TST.

Proteome analysis of bronchoalveolar lavage in individuals from Metsovo, nonoccupationally exposed to asbestos.

Inhabitants of Metsovo, NW Greece, have been exposed to an asbestos whitewash, resulting in malignant pleural mesothelioma (MPM) and pleural calcifications (PCs). Interestingly, those with PCs (PC(+)) are less prone to MPM. They also have lymphocytic alveolitis, and differences in bronchoalveolar lavage (BAL) proteins, compared with those without pleural calcifications (PC(-)). This may mean a different response to the fiber leading to different susceptibility to neoplasia. To further evaluate this, a proteomic analysis of BAL proteins was performed. Proteomic analysis (2D-electrophoresis/Mass Spectrometry) of BAL in Metsovites nonoccupationally exposed to asbestos revealed increased albumin fragments, alpha1-antitrypsin, S100-A9 and HSP27, suggesting ongoing inflammation. In those without pleural calcifications, increased expression of acid ceramidase, glutathione-S-transferase and presence of calcyphosin, all involved in cell cycle regulation and death as well as in the detoxification of mutagenic and toxic agents, lend further support to our thesis of possible "protection against neoplasia" in Metsovites with pleural calcifications.

Decreasing prevalence of pleural calcifications among Metsovites with nonoccupational asbestos exposure.

STUDY OBJECTIVES: Twenty years ago, we reported on a very high prevalence of pleural calcifications (PCs) and malignant mesothelioma among inhabitants of Metsovo, in northwestern Greece. It was shown that both abnormalities were related to asbestos exposure from a whitewash containing tremolite. The fading use of this material has resulted in a decreased incidence of mesothelioma (one third of the original incidence). The aim of the present study was to examine whether PCs among Metsovites has followed a similar trend. DESIGN: Retrospective study. SETTINGS: University Hospital of Ioannina, a tertiary teaching hospital, "G. Hadjikosta" Hospital, a tertiary hospital in Ioannina, and Metsovo Health Center, a primary care center in the town of Metsovo. PATIENTS: Chest roentgenograms of 307 Metsovites, obtained between from 1998 to 2002 were examined. The prevalence of PCs was compared to the one noted 20 years ago. RESULTS: A significantly lower prevalence of calcifications was observed now among younger Metsovites (< 60 years of age). In both studies, there was an increasing rate of PC with age. CONCLUSIONS: The findings of the present study strengthen the incrimination of the whitewash containing tremolite in the development of PCs in Metsovites. The withdrawal of its use in the area has resulted in a null prevalence of PCs in individuals < 40 years old.

Additional proteins in BAL fluid of Metsovites environmentally exposed to asbestos: more evidence of "protection" against neoplasia?

INTRODUCTION: Inhabitants of Metsovo in northwest Greece have been exposed to asbestos from use of a tremolite-containing whitewash ("luto" soil). As a result, they have increased incidence of malignant pleural mesothelioma and pleural calcifications (PCs). However, subjects with calcifications have a much lower incidence of mesothelioma than those without. A previous study of the two groups with BAL revealed higher proportional lymphocytosis among subjects with calcifications. We suggested that BAL lymphocytosis may be somehow correlated with "protection" against neoplasia. METHODS: The present report is a study of the liquid phase of BAL in the two groups. BAL specimens of 43 Metsovites (13 subjects with PCs and 30 subjects without PCs) and two control groups were examined. We measured total protein, albumin, IgG, IgA, and interleukin-6. Proteins were analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional electrophoresis and further characterized using an appropriate computer program. RESULTS: The most interesting finding was the presence of two additional protein spots corresponding to the electrophoretic site of Ig heavy chain and C(4) component of complement. The two proteins were present in all Metsovites with PCs but in none without PCs and also in none of the control groups. CONCLUSION: This study further separates two groups of Metsovites with different reaction to asbestos, possibly as a result of different activation of alveolar macrophages. This difference leads the first group to the formation of PCs, BAL fluid lymphocytosis, and relative "protection" against malignancy, and the second group to no calcifications, no lymphocytosis, but also no protection against malignancy.