The Burden of Silicosis in Michigan: 1988-2016.

RATIONALE: Exposure to respirable crystalline silica causes silicosis, a preventable, progressive occupational lung disease. A more rigorous occupational health standard for silica could help protect silica-exposed workers. OBJECTIVES: To describe trends over 29 years of silicosis surveillance in Michigan. METHODS: Michigan law requires the reporting of silicosis. We confirmed the diagnosis of silicosis in reported cases using medical questionnaires, review of medical records, and chest radiographs. The Michigan Occupational Safety and Health Administration (OSHA) conducted enforcement inspections at the workplaces of the silicosis cases, including air monitoring for silica and evaluation of workplace medical surveillance programs. RESULTS: The Michigan surveillance program identified 1,048 silicosis cases from 1988 to 2016, which decreased from 620 during 1988-1997, to 292 during 1998-2007, to 136 during 2008-2016. The cumulative incidence rate of silicosis decreased from 3.7 to 1.4 to 0.7 cases per 100,000 men 40 years of age and older in Michigan over the same three periods. African Americans had a higher cumulative incidence rate of silicosis, with 6.0 cases per 100,000 African American men 40 years of age and older in Michigan compared with 1.2 cases per 100,000 white men 40 years of age and older in Michigan. The cases identified had severe disease; 59% had progressive massive fibrosis or category 2 or 3 small opacities per B-reading classification of the chest radiograph. Seventeen percent reported ever having active tuberculosis. On spirometry, 76% of ever smokers and 72% of never smokers demonstrated either a restrictive or an obstructive pattern. Most (65%) had not applied for workers' compensation benefits; the percentage who applied for benefits decreased from 42% to 28-16% over the three periods. Thirty-four of 55 (62%) workplace inspections found exposures above the new OSHA 50 µg/m3 respirable crystalline silica permissible exposure limit, and only 11% of inspected companies screened their workers for silicosis. CONCLUSIONS: Adults with confirmed cases of silicosis have advanced disease and morbidity. Most are not using workers' compensation to pay for their care. The new OSHA silica standard, which lowers the permissible exposure limit for silica and requires medical monitoring to identify workers with silicosis, will help reduce the burden of silica exposure. It is critical for pulmonologists to be vigilant to recognize and manage this preventable occupational lung disease.

Predicting survival of lung transplantation candidates with idiopathic interstitial pneumonia: does PaO(2) predict survival?

OBJECTIVE: To find a parameter that would discriminate between the patients with idiopathic interstitial pneumonia who survived to undergo transplantation and those who died while waiting to undergo transplantation. METHODS: A retrospective review was performed of all lung transplant referrals for idiopathic interstitial pneumonia that were listed with United Network for Organ Sharing at the University of California San Diego from January 1990 to February 1999. Of the 331 patients who were listed, 48 met the eligibility criteria. Patient demographics, radiographic studies, pathology reports, and the results of resting and exercise cardiopulmonary function tests were recorded from each patient's chart. Patients were divided into the following two groups: those patients who survived until transplantation and those still waiting were classified as "alive"; and those patients who died before undergoing transplantation were classified as "deceased." RESULTS: Forty-three of 48 patients had a pathologic diagnosis. The cohort included 25 patients with usual interstitial pneumonitis, 3 patients with nonspecific interstitial pneumonitis, 1 patient with desquamative interstitial pneumonitis, and 14 patients with interstitial lung disease of unknown etiology. The only significant difference between the two groups was resting PaO(2) (p = 0.035). A stepwise multivariate analysis demonstrated that PaO(2) and FEV(1)/FVC ratio were significantly associated with survival (hazards ratio, 1.06; confidence interval, 0.99 to 1.13; p = 0.019). CONCLUSIONS: A survival analysis using PaO(2) and FEV(1)/FVC ratio values proved to be statistically significant, but a prospective trial is needed to determine the clinical relevance of these parameters for predicting survival in patients with idiopathic interstitial pneumonia.

Hypersensitivity pneumonitis following anthrax vaccination.

A case of hypersensitivity pneumonitis (HP) following anthrax vaccination is described. The patient is a 39-year-old, previously healthy man on active duty in the US Marine Corps, in whom a urticaral skin rash and progressive dyspnea on exertion developed following subcutaneous anthrax vaccination. A diagnosis of bronchiolitis obliterans with organizing pneumonia was made from transbronchial lung biopsy samples after evaluation excluded multiple infectious and collagen vascular etiologies. This appears to be the first recorded case of HP following an anthrax vaccination; however, a case report of pulmonary and cutaneous vasculitis following hepatitis B vaccination has been reported in the literature and is reviewed.