Role of Molds in Farmer's Lung Disease in Eastern France

Abstract

Farmer's lung disease (FLD) is common in the east of France. In the absence of the primary recognized FLD agent, Saccharopolyspora rectivirgula, its etiology remains unknown. A prospective case-control study was performed to find the etiology of FLD in this area. Eleven patients were matched with 11 healthy control farmers. Twenty-two urban subjects constituted the nonexposed control group. Microorganisms from cowshed air and fodder were identified and counted. The antigens of the microorganisms most frequently isolated at the 22 farms were used for serological tests. Farms of patients with FLD contained more Absidia corymbifera than those of healthy farmers (p < 0.05 in air, p < 0.01 in fodder). Electrosyneresis, performed with A. corymbifera somatic antigen, differentiated 9 of 11 patients with FLD from control subjects (p < 0.01). Other significant results were obtained with Eurotium amstelodami (p < 0.01) and Wallemia sebi (p < 0.05). In contrast, no significant results were obtained with the other seven antigens tested, including S. rectivirgula. Absidia corymbifera and, to a lesser degree, W. sebi or E. amstelodami are likely to be the main causes of FLD in this area. Modifications in working conditions over time could explain the emergence of these new contributing etiologies.

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

“…Among these criteria, serology has long been considered to be either a minor criterion or a simple marker of exposure [23][24][25][26]. However, with typical FL patients, the use of antigens isolated from patients' environments has lead to convincing results [11,27]. In addition, a recent study by LACASSE et al [4] identified serum precipitins as a significant predictive factor of HP, regardless of exposure.…”

“…and hay extract. Antigen extracts were produced and tested as described in a previous article [11]. The immunological methods used were agar gel double diffusion and electrosyneresis on cellulose acetate, which, as shown by a recent study, are more relevant than ELISA and immunoblots in discriminating FL from healthy exposed dairy farmers in the present study's region [12].…”

“…The choice of antigenic panel was based on the recognised causes of FL and HP due to moulds at an international [15,16] and local level [11]. The antigenic panel tested included Absidia corymbifera, Eurotium amstelodami, Wallemia sebi, Aspergillus fumigatus, Saccharopolyspora rectivirgula, mesophilic Streptomyces sp.…”

“…Subjects were tested by two serological techniques (electrosyneresis and double diffusion) for a panel of seven antigens. The choice of both immunological methods and the antigenic panel was based on previous studies aimed at identifying the best immunological set for diagnosing HP in the present study's region [11,12].…”

Hypersensitivity pneumonitis

“…The selection of antigens to be tested often needs to be determined locally according to the prevalent antigens (4,51). In eastern France, by using a panel of antigens really responsible for farmerÕs lung and not a classical standardized panel, serological tests showed a high rate for sensitivity and specificity (52).…”