[Langerhans cell histiocytosis. Clinical longitudinal study of 21 patients]

Clinical data of patients with Langerhans cell histiocytosis are well established, although new diagnostic methods and specially long term evolution of the disease with lung involvement are not well-known.

In all cases, patients were diagnosed by means of pathologic study of the lung samples, either by transbronchial biopsy in 7 patients, or by surgical lung biopsy in 8 patients. Six patients were diagnosed by bone biopsy. Other patients were diagnosed by bronchoalveolar lavage (BAL). In 4 patients, who underwent BAL, the study of antibodies CD1 (CD1a) was positive (> 5%). Lymphocytopenia was detected in 28% of patients, whereas no decrease in delayed cutaneous hypersensitivity tests was detected in any of them. After a follow-up study of 12.8 years (range: 4-22 years), 7 patients had dead, 6 patients showed severe lung involvement and other 5 patients did not have lung affection.

The diagnosis of Langerhans cell histiocytosis has improved by detection of immunologic and histochemical markers recently introduced. The study of the delayed cutaneous hypersensitivity tests did not show anergy or hipoergy. Long term evolution of patients with lung involvement is poor.