Quantitative assessment of specific serum IgGs may verify source of environmental exposure in extrinsic allergic alveolitis (EAA)

Abstract

Abstract: Assessment of humoral response to inhalation antigens is currently the most frequently used method to confirm exposure. It may be useful in extrinsic allergic alveolitis (EAA) patients, especially in cases that are unaware of the source of exposure. However, commercially available test may not include relevant antigens, which may lead to false negativity of the test. We proposed that testing patient serological responses to antigens from respectively environments might be useful in showing the relevance of these exposures. Ten patients diagnosed with EAA were included in the case-control study. Samples from potentially harmful environments were collected, and antigenic extracts were prepared and used for enzyme-linked immunosorbent assays (ELISA) to investigate serological responses to suspected antigens. Plasma samples of unexposed volunteers were used as controls. The results were interpreted in the context of other clinical findings when known (e.g., radiologic patterns, bronchoalveolar lavage fluid findings, histology results) and patient history. We suggest that environmental sampling may provide more information than previous history assessment and commercially available specific IgGs tests and helps to either reveal hidden exposures or find relevant exposure in cases with multiple potential sources. The results of these tests must be interpreted carefully in the context of other clinical data.

Keywords

• extrinsic allergic alveolitis
• exposure
• antigen
• immunoglobulin g
• humoral response