PMC9483807_01
High resolution computed tomography demonstrated emphysema, reticulation, and honeycombing without nodular shadows and mosaic pattern suggesting fibrotic hypersensitivity pneumonitis. (A) Before admission. (B) At admission, the density of lung field increased slightly and diffusely. (C) Two years after addition of oral glucocorticoid, the density of lung field improved.
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The IPF had been diagnosed based on the presence of the interstitial pneumonia (UIP) pattern on high-resolution computed tomography (HRCT) (Fig. 1A), and the absence of collagen vascular disease. The density of both lung fields appeared diffusely increased when compared with that of 2 years previous (Fig. 1B). Subsequently, the dose of oral prednisolone was gradually reduced to 6.5 mg daily, and the patient's condition remained stable for over 2 years (Figs. 1C and 5).
Environmental assessment. (A) A roll of hay in the patient's farm. (B) The compost area.
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Eight years before admission, he started to make compost from hay in an area approximately 100 m away from his house (Fig. 2).
Transbronchial lung biopsy shows mild alveolitis and fibrosis without granuloma. (A) Hematoxylin and Eosin staining, x200. (B) Elastica van Gieson staining, x200.
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B3, B4, and B8) revealed alveolitis without granulomas (Fig. 3). Because of BALF lymphocytosis and fluctuation of symptoms, we suspected fibrotic HP due to hay and observed the patient without therapy at our hospital as an antigen avoidance test.
Time course of SpO2 during the 6-min walk test. Walking distance was 375 m (both on admission and 2 weeks later). SpO2: oxygen saturation.
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After 2 weeks, LDH, CRP, PaO2, alveolar-arterial oxygen difference (A-aDO2), and oxygen desaturation on the 6-min walk test had improved (Table 1, Fig. 4).
Clinical course. Addition of prednisolone to Nintedanib decreases serum KL-6 and SP-D levels, and increases %DLCO. IPF: idiopathic pulmonary fibrosis, HP: hypersensitivity pneumonitis, KL-6: Krebs von den Lungen-6, SP-D: pulmonary surfactant protein-D, DLCO: diffusing capacity of the lung for carbon monoxide, FVC: forced vital capacity.
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Subsequently, the dose of oral prednisolone was gradually reduced to 6.5 mg daily, and the patient's condition remained stable for over 2 years (Figs. 1C and 5).