[A patient with idiopathic bronchiolitis obliterans with organizing pneumonia and idiopathic CD4+ T-lymphocytopenia].

Idiopathic bronchiolitis obliterans organizing pneumonia (idiopathic BOOP) and idiopathic CD4+ T lymphocytopenia are syndromes of unknown origins which have been characterized in recent years. An important feature of both syndromes is the good prognosis. The clinical and histological features of idiopathic BOOP are unspecific but characteristic, whereas the clinical features of idiopathic CD4+ T lymphocytopenia are not homogeneous. We present a report on the first patient in whom both syndromes were found simultaneously. Initially the chest x-ray showed bilateral patchy opacities and the peripheral blood showed a severe CD4+ T cell depletion. The diagnosis of BOOP was verified by open lung biopsy, which demonstrated the histological features of BOOP. No evidence was found of congenital or acquired reasons associated with CD4+ T cell depletion or with the histological features of BOOP, which implies the diagnosis of idiopathic CD4+ T lymphocytopenia and idiopathic BOOP. Within a follow-up period of 14 months the pulmonary opacities disappeared completely and the CD4+ T cells increased, but did not reach normal values.