ABSTRACT

Background: Histopathological and Ultrastructural (HU) findings described on chronic phase of Hypersensitivity Pneumonitis (NH) are characteristic, thus they could help to differentiate itself from other Diffuse Interstitial Lung Disease (DILD) identifying those cases with difficult clinical-epidemiological diagnosis in Venezuelan patients on chronic phase of NH. The purpose of this study was to investigate for the first time the HU characteristics of open lung biopsies from Venezuelan patients on chronic phase of NH.
Material and methods: Tissue fragments from open lung biopsy were processed for optical and transmission electron microscopy; with patients consent.
Results: All cases showed patchy chronic interstitial pneumonitis, lymphocitic alveolitis, fibrous plugs in bronchioles and alveoli, interstitial fibrosis, centriacinar emphysema, and obstructive pneumonia. Ultrastructuraly, there were lymphocytes with large and convoluted nuclei, multinucleated giant cells, intraalveolar fibrous plugs, type II pneumocytes hyperplasia, capillaries with fenestrated endothelium and reduplication of the basal membrane, and interaction between alveolar lymphocytes and macrophages.
Conclusions: Morphological analysis by optical and electron microscopy allows not only to recognize late pathological stages of the disease, but also helps to differentiate it from other DILD in Venezuelan patients. No benefits were found in the use of electron microscopy for the diagnosis of NH.

KEYWORDS

Extrinsic allergic alveolitis, hypersensitivity, pneumonitis.

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