Elevated levels of IgG and IgA (classes of immunoglobulins) may be seen, as well as the presence of rheumatoid factor (an indicator of autoimmunity). Hemagglutination, a clumping of red blood cells in response to the presence of antibodies in the blood, may also occur. Neutrophils, beta-defensins, leukotrienes, and chemokines can also be detected in bronchoalveolar lavage fluid injected then removed from the bronchiolar airways of individuals with DPB, for evaluation. Differential diagnosis
In the differential diagnosis (finding the correct diagnosis between diseases that have overlapping features) of some obstructive lung diseases, DPB is often considered. A number of DPB symptoms resemble those found with other obstructive lung diseases such as asthma, chronic bronchitis, and emphysema. Wheezing, coughing with sputum production, and shortness of breath are common symptoms in such diseases, and obstructive respiratory functional impairment is found on pulmonary function testing. Cystic fibrosis, like DPB, causes severe lung inflammation, excess mucus production, and infection; but DPB does not cause disturbances of the pancreas nor the electrolytes, as does CF, so the two diseases are different and probably unrelated. DPB is distinguished by the presence of lesions that appear on X-rays as nodules in the bronchioles of both lungs; inflammation in all tissue layers of the respiratory bronchioles; and its higher prevalence among individuals with East Asian lineage.DPB and bronchiolitis obliterans are two forms of primary bronchiolitis. Specific overlapping features of both diseases include strong cough with large amounts of often pus-filled sputum; nodules viewable on lung X-rays in the lower bronchi and bronchiolar area; and chronic sinusitis.
The onset of symptoms can range from weeks up to tens of years from the initial exposure. In some individuals, a single exposure to beryllium can cause berylliosis. Pathogenesis
In susceptible persons, beryllium exposure can lead to a cell-mediated immune response. The T-cells become sensitized to beryllium. Each subsequent exposure leads to an immune response involving CD4+ helper T-lymphocytes and macrophages accumulating in the lungs. As this response continues macrophages, CD+4 T-lymphocytes and plasma cells aggregate together to form the noncaseating granulomas. When beryllium is phagocytized by macrophages, the beryllium triggers macrophage apoptosis, thereby reducing beryllium clearance from the lungs and eventually resulting in secondary necrosis and lysis. Eventually, the outcome is fibrosis of the lung.Several studies have shown that there is a genetic component to beryllium sensitivity. Specifically, those beryllium exposed workers with a mutation at the HLA-DPB1 Glu69 position have increased prevalence of beryllium sensitization and CBD. The HLA-DPB1 gene is important for MHC class II molecule function on antigen presenting cells.According to the International Agency for Research on Cancer (IARC), beryllium and beryllium compounds are Category 1 carcinogens; they are carcinogenic to both animals and humans. Diagnosis
The differential diagnosis for berylliosis includes:
Sarcoidosis
Granulomatous lung diseases
Tuberculosis
Fungal infections (e.g., histoplasmosis)
Granulomatosis with polyangiitis
Idiopathic pulmonary fibrosis
Hypersensitivity pneumonitis
AsthmaOf these possibilities, berylliosis presents most similarly to sarcoidosis. Some studies suggest that up to 6% of all cases of sarcoidosis are actually berylliosis.Definitive diagnosis of berylliosis is based on history of beryllium exposures, documented beryllium sensitivity and granulomatous inflammation on lung biopsy.