Pneumonia de hipersensibilidade subaguda: ocorrência em familiares / Sub acute hypersensitivity pneumonitis: incidence among family members

OBJETIVO: Descrever um caso de pneumonia de hipersensibilidade subaguda em criança com ocorrência concomitante da mesma doença em um familiar. DESCRIÇÃO DO CASO: Paciente de 12 anos encaminhado para investigação de dispnéia progressiva, tosse seca e emagrecimento. Realizou vários tratamentos por hipótese de pneumonias bacterianas de repetição. Após diagnóstico radiológico e histopatológico de pneumonia de hipersensibilidade, apresentou melhora clínica com remoção da exposição. A mãe do paciente foi internada no mesmo período com quadro clínico-radiológico e diagnóstico semelhantes. COMENTÁRIOS: A pneumonia de hipersensibilidade representa um grupo de doenças caracterizadas por processo inflamatório, que compromete o parênquima pulmonar e as vias aéreas em resposta a uma exposição a grande variedade de antígenos inalados. Pode se apresentar sob as formas aguda, subaguda ou crônica. Sua incidência varia de acordo com aspectos ambientais e geográficos. Somente 25% dos pacientes têm histórico familiar. A existência de predisposição genética para a doença ainda é desconhecida.

OBJECTIVE: To describe a case of subacute hipersensitivity pneumonitis in a boy with simultaneous occurrence of the same clinical syndrome in a member of his family. CASE DESCRIPTION: A 12 years old child with worsening dyspnea, dry cough and weigth loss. He had no improvement despite several treatments for bacterial pneumonia. The diagnosis of hypersensitivity pneumonia was made based on radiologic and hystophatologic patterns, and the patient got better after removal of exposure. The mother of the patient had a similar clinical and radiologic disease at the same period. COMMENTS: The hypersensitivity pneumonitis represents a group of diseases characterized by inflammatory damage of lung parenchyma and airways in response to inhalation of a large variety of antigens. The clinical presentation varies with acute, subacute and chronic forms. Its incidence also varies considerably, depending on environmental and geographic conditions. Only 25% of cases have a family history of the disease. The existence of an exact genetic risk factor is still unknown.

HRCT Findings of Hypersensitivity Pneumonitis: Correlation with Pulmonary Function Test

PURPOSE: To evaluate the HRCT findings of hypersensitive pneumonitis and to correlate the findings with the results of the pulmonary function test (PFT). MATERIALS AND METHODS: Seven patients in whom hypersensitive pneumonitis was histologically confirmed (by transbronchial lung biopsy in two, thoracoscopic lung biopsy in one, open lung biopsy in two, and typical clinical and laboratory findings in two) were involved in this study. Their radiological patterns were assessed by HRCT and the extent of each finding was evaluated semi-quantitatively and correlated with the results of the pulmonary function test. RESULTS: The HRCT findings were as follows: lobular overinflation (n = 7), ground glass attenuation (n = 7), centrilobular nodule (n = 6), reticular opacity (n = 5), interlobular septal thickening (n = 3), consolidation (n = 2), and irregular subpleural line (n = 1). Five patients showed lower lung predominance and two, middle lung predominance. In all, a restrictive pattern and diminished diffusion capacity was noted. The grade score of reticular opacity showed significant correlation with forced vital capacity and forced expiratory volume. There was, however, no significant correlation between other HRCT findings and PFT results. Two patientsin whom lobular overinflation associated with parenchymal fibrosis was noted showed a decreased maximal midexpiratory flow rate of 25 -75. CONCLUSION: Lobular overinflation, ground-glass attenuation and centrilobular nodules are commonly observed in hypersensitive pneumonitis. The only significant correlation between each HRCT finding and the pulmonary function test was that between reticular opacity and both forced expiratory volume and forced vital capacity. In cases of chronic hypersensitive pneumonitis presenting as pulmonary fibrosis, associated lobular overinflation could be helpful for differential diagnosis.