The role of pathologists in the diagnosis of occupational lung diseases: an expert opinion of the European Society of Pathology Pulmonary Pathology Working Group

Fibrotic Hypersensitivity Pneumonitis: A Diagnostic Challenge Leading to Lung Transplantation

Background/Objectives: Hypersensitivity pneumonitis (HP), a subtype of interstitial lung disease (ILD), is often misdiagnosed as idiopathic pulmonary fibrosis (IPF), particularly when the causative antigen cannot be identified. Typically resulting from chronic exposure to inhaled organic particles smaller than 5 microns, HP presents a diagnostic challenge. This report outlines a case of fibrotic HP initially misclassified as asthma. No triggering antigen was identified despite extensive investigation. The disease progressed despite corticosteroid, immunosuppressive, and antifibrotic therapy, ultimately leading to an advanced fibrotic stage and requiring lung transplantation. This clinical course is rare and infrequently reported, particularly in cases requiring lung transplantation without an identifiable causative antigen. Such progression is uncommon and underreported, especially in patients initially misclassified as having asthma. Methods: Medical records of 24 patients diagnosed with HP were reviewed. Only one case demonstrated progression to fibrotic HP; this case was selected for detailed analysis. Results: Clinical and functional deterioration occurred despite standard therapy. Given the advanced stage of fibrosis and treatment resistance, lung transplantation was deemed the next appropriate therapeutic option. Conclusions: HP remains underdiagnosed due to difficulties in identifying the causative antigen and overlapping features with other ILDs. Early and accurate differentiation from IPF is essential, particularly in progressive fibrotic forms unresponsive to conventional therapies.

Silica dust exposure and associated pulmonary dysfunction among mine workers

This study assessed the impact of silica exposure on 145 mine workers in Mianwali, Punjab, Pakistan, compared to 45 non-exposed individuals. Pulmonary function tests revealed significantly reduced lung function in exposed workers (P < 0.05), with declines in Forced Expiratory Volume in one second (FEV1), Forced Vital Capacity (FVC), FEV1/FVC ratio, Peak Expiratory Flow, and Forced Expiratory Flow at 25-75% of FVC (FEF25-75). Radiological evaluations confirmed extensive lung damage (P < 0.05), including pleural effusion, reticular shadowing, and lung consolidation. Oxidative stress markers demonstrated increased lipid peroxidation, Fenton's Oxidative Stress, and Oxidative Stress Index (P < 0.05), along with reduced antioxidant enzyme activities, including Catalase, Superoxide Dismutase, Total Antioxidant Capacity, and Glutathione Peroxidase. Hematological analysis showed elevated White Blood Cells, Lymphocyte percentage, Hemoglobin, Hematocrit, Mean Corpuscular Volume, and Mean Corpuscular Hemoglobin (P < 0.05), reflecting systemic inflammation. Silica's piezoelectric properties contributed to oxidative stress and cellular damage, exacerbating pulmonary dysfunction. These findings highlight silica exposure as a severe occupational hazard, causing irreversible lung impairment and systemic oxidative imbalance. Implementing strict safety protocols, personal protective measures, and regular health monitoring is crucial to safeguarding workers.

Giant cell interstitial pneumonia: case series with comprehensive ultrastructural analyses of "not only" hard metal pneumoconiosis

AIMS

Giant cell interstitial pneumonia (GIP) is a fibrosing lung disease histologically characterized by centrilobular pulmonary fibrosis and cannibalistic intra-alveolar multinucleated giant cells. It is considered a form of pneumoconiosis caused particularly by secondary exposure to hard metals (cemented carbide or tungsten carbide). Hard metals are commonly used in various industrial applications, such as cutting tools, drilling tools, machine inserts, and other wear-resistant components. However, cases with unknown exposure that recurred in transplanted lungs have been described. This has led to the hypothesis of a complex etiopathogenesis, likely multifactorial, involving the coparticipation of immune mechanisms. We aimed to identify all the elements present in a series of GIP lung samples to better understand the pathogenic mechanisms of the disease.

METHODS AND RESULTS

We describe five cases of histologically diagnosed GIP in patients with occupational exposure to metallic dust using ultrastructural characterization to identify metal dust and to quantify asbestos fibres. We found that tungsten was present in three cases, albeit in trace amounts in two of them. Numerous elements were identified in all samples, including asbestos fibres in patients with endstage pulmonary fibrosis. Furthermore, in one of the described cases the recurrence of the disease was also observed in transplanted lungs.

CONCLUSION

These findings support the hypothesis that GIP may be due to elements other than hard metals, with asbestos possibly representing a contributory factor in the expression of a more severe fibrotic disease. The recurrence of GIP observed in transplanted organs strengthens the hypothesis of the existence of a not yet fully understood etiopathogenic immune mechanism.