We prospectively followed 68 patients diagnosed as idiopathic interstitial pneumonia (IIP) over a period of 1-11 years. Thirteen patients (19%) subsequently developed systemic manifestations of collagen vascular diseases (CVD) and were diagnosed as having had interstitial pneumonia as the sole presentation of CVD (CVD-IP). Compared with the 55 IIP patients, the 13 CVD-IP patients were relatively younger, predominantly female, and had a lower incidence of dust inhalation in their history. They also had a higher erythrocyte sedimentation rate, higher incidence of the x-ray finding of discoid atelectasis in the lower lung fields, and a better prognosis than the IIP patients. However, these features did not clearly distinguish the two groups. We conclude that the patients clinically and/or histologically defined as suffering from IIP cannot be distinguished from CVD-IP patients before systemic signs of CVD appear in the latter group.

Although the prevalence of serum precipitating antibodies for farmer's lung disease (FLD) is lower in smokers than in nonsmokersand FLDpredominates in nonsmokers, the affects of smoking on the clinical course of the disease is not known.Wecomparedthe clinical findings and the prognosis between 12 smokers (SM-FLD)and 31 non-smokers with FLD(NS-FLD). There was no difference in age, sex, working years on farm, clinical symptoms, laboratory findings, radiographic findings, between the two groups. However, for the type of onset on the first visit for FLD, "acute single episode" type was less common,and "recurrent" and "insidious onset" types were more common in SM-FLD than in NS-FLD (8.3 vs 58.1, 91.7 vs 41.9%, respectively, p<0.05). Although working status and mask wearing status were not significantly different between the two groups after the diagnosis of FLD, patients with symptoms and/or radiographic abnormalities of FLD of more than 6 months were found more frequently in SM-FLD than in NS-FLD (66.7 vs 19.4%, p<0.005). And also SM-FLDhad more recurrences of FLD than NS-FLD after the initial diagnosis ofFLD (1.58±1.56 vs 0.47±1.07, p<0.05). SM-FLDtended to have lower %VCthan NS-FLD (73.6±7.4 vs 88.5±3.9%, respectively, p=0.06). Regarding the prognosis, the 10-year survival rates were 70.7% in SM-FLD, and 91.5% in NS-FLD(p<0.05). These results suggest that smoking may make FLDinsidious and chronic, and deteriorates the clinical outcome. (Internal Medicine 34: 966-971, 1995)

To examine factors that influence changes in Micropolyspora faeni (MF) antibody titer in farmer's lung disease (FLD), we followed for 5 yr the prevalence of serum MF antibody and the epidemiologic factors (years on farm, hours in barn, and hay-handling time) among 92 dairy farmers in Hokkaido, Japan. The prevalence of MF antibody among nonsmokers was significantly higher than that among smokers: 27.1% versus 7.7% in 1979, 31.3% versus 2.9% in 1984. There was no remarkable change in overall prevalences of MF antibody between 1979 and 1984 (18.5 and 19.6%, respectively). However, out of 17 seropositive farmers, six (35%) became seronegative, and out of 75 seronegative farmers, seven (9.3%) became seropositive after 5 yr. The nonsmoking farmers who remained seronegative throughout the follow-up period were older and had worked longer on farms than the farmers with seroconversion. These results suggest that in addition to smoking habits, age and exposure time to MF influence the immune response to MF in dairy farmers. Out of 11 farmers who remained seropositive throughout the 5-yr period, two (18.2%) developed FLD. Therefore, continuously positive MF antibody is one of the risk factors in the development of FLD.

No abstract

Lung crackles may be produced by the opening of small airways or by the sudden expansion of alveoli. We studied the generation of crackles in excised canine lobes ventilated in an airtight box. Total airflow, transairway pressure (Pta), transpulmonary pressure (Ptp), and crackles were recorded simultaneously. Crackles were produced only during inflation and had high-peak frequencies (738 +/- 194 Hz, mean +/- SD). During inflation, crackles were produced from 111 +/- 83 ms (mean +/- SD) prior to the negative peak of Pta, presumably when small airways began to open. When end-expiratory Ptp was set constant between 15 and 20 cmH2O and end-expiratory Ptp was gradually reduced from 5 cmH2O to -15 or -20 cmH2O in a breath-by-breath manner, crackles were produced in the cycles in which end-expiratory Ptp fell below -1 to 1 cmH2O. This pressure was consistent with previously known airway closing pressures. When end-expiratory Ptp was set constant at -10 cmH2O and end inspiratory Ptp was gradually increased from -5 to 15 or 20 cmH2O, crackles were produced in inspiratory phase in which end-inspiratory Ptp exceeded 4-6 cmH2O. This pressure was consistent with previously known airway opening pressures. These results indicate that crackles in excised normal dog lungs are produced by opening of peripheral airways and are not generated by the sudden inflation of groups of alveoli.