26857 Hypersensitivity Pneumonitis Panel, Immunoglobulin G, Serum (BHYPS)

​​Allergic Lung Serology; Aeroallergen; Allergic bronchopulmonary aspergillosis; ABPA; Alternaria alternata; Alternaria tenuis; Alternaria tenuis/alternata; Aspergilloma; Aspergillosis; Aspergillus fumigatus; Asthma; Aureobasidium pullulans; Bagassosis; Chronic pulmonary aspergillosis; Dematiaceous fungus; Farmer's Lung Antibody; Farmer's Lung Disease; Fumigatus; Fungal sensitizer; Air conditioner lung; Hay fever; Hot tub lung; Humidifier lung; Hypersensitivity pneumonitis; Laceyella sacchari; Micropolyspora faeni; Neocamarosporium betae; non-tuberculous mycobacteria (NTM); Penicillium chrysogenum; Penicillium notatum; Phoma betae; Saccharopolyspora rectivirgula; Saprophyte; Saprophytic fungus; Trichoderma viride​

​Evaluation of patients suspected of having hypersensitivity pneumonitis induced by exposure to Alternaria tenuis/alternata, Aspergillus fumigatus, Aureobasidium pullulans, Laceyella sacchari, Micropolyspora faeni, Penicillium chrysogenum/notatum, Phoma betae, and Trichoderma viride

​IgG antibodies to Alternaria tenuis/alternata, Aspergillus fumigatus, Aureobasidium pullulans, Laceyella sacchari, Micropolyspora faeni, Penicillium chrysogenum/notatum, Phoma betae, and Trichoderma viride may be found in sera from healthy individuals; the presence of these specific antibodies is not sufficient to establish the diagnosis of hypersensitivity pneumonitis.​

Elevated concentration of antibodies to Aspergillus fumigatus may be also found in patients with invasive aspergillosis and cavitary lung disease.

The concentrations of antibodies to these antigens may decrease following treatment, although elevated concentrations may persist in treated patients.

The test method utilizes the fluorescence enzyme immunoassay (FEIA) on Phadia ImmunoCAP 250. Values obtained using the same test system or different assay methods cannot be used interchangeably. Alternative reference values established utilizing the same reagents or test system may be influenced by the characteristics of the local cohorts and environmental exposures.

​Hypersensitivity pneumonitis (HP) is a complex inflammatory lung disease triggered by repeated inhalation of various organic and inorganic antigens in susceptible individuals. The condition presents significant diagnostic challenges due to its diverse clinical presentations, variable disease progression, and overlap with other interstitial lung diseases. The 2020 American Thoracic Society and Japanese Respiratory Society, and Asociacion Latinoamericana del Torax (ATS/JRS/ALAT) Clinical Practice Guideline emphasizes that HP diagnosis requires a comprehensive multidisciplinary approach integrating clinical history, exposure assessment, radiological findings, and when necessary, histopathological examination. Currently, no single test is sufficient for definitive diagnosis of HP.

Serum IgG testing serves as one component of the diagnostic workup for HP, particularly in identifying specific antigenic exposures. However, studies demonstrate significant limitations in the diagnostic performance of serum IgG testing alone. The clinical validity of HP antibody assays is enhanced when used within a structured diagnostic framework. Multidisciplinary team meetings have shown improved diagnostic agreement in diffuse parenchymal lung diseases, highlighting the importance of integrating serological findings with other clinical data rather than relying on laboratory results in isolation. Contemporary understanding of HP recognizes an expanding spectrum of causative agents beyond traditional organic dust. Occupational causes encompass diverse antigens including microbial agents, animal proteins, and chemical compounds. The use of multi-analyte antibody panels can help identify specific antigenic exposures, particularly in occupational settings, though the absence of detectable antibodies does not exclude HP diagnosis.

Recent research has identified distinct clinical phenotypes in HP that may influence the interpretation of serological testing. The relationship between specific exposures and clinical presentations varies considerably, with some patients developing disease despite minimal apparent exposure while others with significant exposure remain asymptomatic. The pathogenesis of HP involves complex immune mechanisms beyond simple antibody-mediated responses, including T-cell activation and inflammatory cascades. This complexity underscores why serological testing alone cannot be used to establish or exclude the diagnosis of HP. In addition, reference intervals for the analytes tested do vary between laboratories, even when the same instrument and reagents are used.

The panel's clinical validity is established through its ability to identify specific antigenic exposures and immune responses associated with HP, while requiring integration with comprehensive clinical assessment for optimal diagnostic accuracy. Healthcare professionals should utilize these assays as one component of a comprehensive diagnostic evaluation, maintaining awareness of their limitations while leveraging their potential to identify relevant exposures and guide further clinical investigation.

Antibody levels greater than the reference range indicate that the patient has been immunologically sensitized to the antigen or a related antigen. The significance of an elevated antibody response is dependent on a combination of patient's clinical history, HRCT (high-resolution computed tomography) scan findings, pathological examination, and certain risk factors (eg, environmental and occupational determinants). Results must be interpreted as a component of a comprehensive diagnostic evaluation and known limitations of hypersensitivity tests.