Giant Cell Interstitial Pneumonia (Hard Metal Lung Disease, Cobalt Lung)

Abstract

Hard metal lung disease is a rare form of occupational lung disease that can occur in workers engaged in the manufacture, utilization, or maintenance of tools composed of hard metal [a material composed mainly of tungsten carbide (WC) and cobalt] or diamond-cobalt. Clinically, the condition resembles hypersensitivity pneumonitis, with subacute presentations and possible evolution to pulmonary fibrosis. However, this interstitial lung disease is uniquely characterized by the presence of bizarre ;;cannibalistic'' multinucleated giant cells in the alveoli and the bronchoalveolar lavage. A pathological diagnosis of giant cell interstitial pneumonitis (GIP) is, therefore, specific for hard metal lung disease, even though not all affected subjects exhibit this pathognomonic feature. Cobalt is the critical toxic component causing hard metal lung disease, hence also the term cobalt-lung. Hard metal lung disease is more likely to occur in poorly regulated workplaces, but its occurrence depends mainly on individual susceptibility, rather than on cumulative exposure, so that even young subjects may be affected.

Nanotoxicity: emerging concerns regarding nanomaterial safety and occupational hard metal (WC-Co) nanoparticle exposure

“…57,63,69 In some cases, WC-Co particle "deposits" have been found in biopsy specimens, confirming causative exposure to WC-Co dust and HMLD diagnosis. 62,63,69,70 It has been hypothesized that there may be an allergic reaction or a genetic predisposition which may contribute to the development of HMLD in certain individuals.…”

“…It has recently been established that the defining characteristic of HMLD is the presence of "bizarre, cannibalistic, multinucleated giant cells" in lung biopsy specimens of workers exposed to WC-Co. 57,61,63,65,68,69 These giant cell complexes are thought to originate from macrophages which have engulfed WC-Co particles, which then stimulate inflammatory and fibrotic processes in the surrounding lung tissue. 57,63,69 In some cases, WC-Co particle "deposits" have been found in biopsy specimens, confirming causative exposure to WC-Co dust and HMLD diagnosis.…”

“…44,[51][52][53][54][55][56][57][58][59] Diagnosis of HMLD is a challenge, as symptoms are general and often mistaken for other respiratory ailments: patients often report difficulty breathing and present with reduced lung capacity, progressive lung inflammation, and eventual fibrosis. 57,60,61 HMLD has been reported in hard metal manufacturing and oil and mining/drilling industries, where workers were exposed to WC-Co dusts or fumes on a daily basis for a number of years prior to diagnosis. 44,51,[62][63][64][65] Currently, treatments are limited and no disease-specific therapy or diagnostic tool exists.…”

Hard Metal Lung Disease Successfully Treated with Inhaled Corticosteroids

“…In addition, infiltration of lymphocytes and macrophages was observed in the alveolar space. Restrictive or mixed obstructive and restrictive impairment of the pulmonary function is observed in patients with HMLD (14)(15)(16). In the present case, obstructive parameters were impaired with decreased values of %PEFR and %FEF25-75 on the first admission.…”

Chronic cough – occupational considerations

“…129 Examples of less common occupational diffuse lung diseases include berylliosis (a granulomatous disease because of working with or near the metal beryllium), 130 and hard metal lung disease (a giant cell interstitial pneumonia in hard metal tool workers exposed to cobalt and tungsten carbide). 131 These conditions may be clinically and radiologically indistinguishable from the non-occupational respiratory conditions sarcoidosis and idiopathic pulmonary fibrosis, respectively. Without a detailed occupational history, these conditions are likely to remain unsuspected, which may leave workers harmfully exposed, or more likely prevent adequate compensation advice.…”