Diagnostic Accuracy of Transbronchial Biopsy in Acute Farmer’s Lung Disease: Gold Standards for the Diagnosis of FL and Control Samples

11 Mar
2014

Diagnostic Accuracy of Transbronchial Biopsy in Acute Farmer’s Lung Disease: Gold Standards for the Diagnosis of FL and Control SamplesThe analysis of the biopsy specimens for each criterion was performed according to the following scales. First, granulomas were graded on a 0- to 2-point scale (0/2: no granuloma found; 1/2: presence of isolated multinucleated giant cells or of loose (poorly circumscribed) clusters of epithelioid cells; 2/2: well-organized granulomas). Second, diffuse lymphocytic infiltration was graded on a 0- to 3-point scale (0/3: absence of infiltration; 3/3: severe lymphocytic infiltration). Third, focal lymphocytic infiltration was also graded on a 0- to 3-point scale. canada viagra

Overall Assessment: The pathologists were then asked to perform an overall assessment of the TBB specimen as they would have done in any clinical situation, and to classify each of them into one of four categories: probable FL, indicating that FL stood on top of the differential diagnosis; possible FL, indicating that FL was considered among other diagnoses; nonspecific; and alternative diagnosis. Normal biopsy specimens were classified under “alternative diagnosis.”
Gold Standards for the Diagnosis of FL and Control Samples
Although gold standards are usually based on definitive pathologic anatomy, they are evolving to include either typical findings or important features of the subsequent clinical course and prognosis of patients with differing diagnostic test results. Thus, diagnosis of acute FL was based on the association of clinical criteria. The five following criteria were considered as required for the diagnosis: definite exposure to moldy hay; typical history of late afternoon or early evening fever, chills, or dyspnea; inspiratory crackles; lymphocytic alveolitis on BAL (defined as >22% on lymphocytes of BAL cell analysis); and resolution of clinical symptoms following treatment consisting of oral corticosteroids and/or withdrawal from exposure to offending antigens. Most patients were seen within 1 month of the appearance of the symptoms. Abnormal results of pulmonary function tests, basal infiltrates on chest radiographs, and presence of serum precipitins to Saccharopolijspora rectivirgula were not regarded as necessary for the diagnosis, but were helpful to further support it. The final diagnoses of the control cases were obtained from open lung biopsy specimens or, most often, from clinical findings associated with long-term follow-up.

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