Diagnostic value of serum precipitins to mould antigens in active hypersensitivity pneumonitis.

Serum precipitins have a controversial diagnostic value in hypersensitivity pneumonitis (HP). The present authors' objective was to assess their diagnostic value by developing scores from a panel of specific antigens tested by two techniques (electrosyneresis and double diffusion) to discriminate active HP from other interstitial lung diseases. Consecutive patients presenting with a condition for which HP was considered in the differential diagnosis were included in the study. All patients underwent the same standardised diagnostic procedure, including precipitin tests performed in routine conditions. Clinical manifestations, bronchoalveolar lavage and high-resolution computed tomography defined the presence or absence of HP. Receiver-operating characteristic curves and logistic regression were used to develop the serological scores. A total of 122 patients (including 31 cases of HP) were included in the study. Five antigens from the panel were selected for the serological scores (Absidia corymbifera, Eurotium amstelodami, Wallemia sebi, Saccharopolyspora rectivirgula and mesophilic Streptomyces sp.). Electrosyneresis was more discriminative than the double-diffusion technique. Predictive negative values varied 81-88% and predictive positive values varied 71-75% for prevalence of HP 20-35%. In conclusion, serological scores using a panel of relevant antigens may guide both biological and clinical practice in areas of high prevalence of hypersensitivity pneumonitis.