Evidence of lymphocyte alveolitis by bronchoalveolar lavage in thalassemic patients with pulmonary dysfunction

Pulmonary dysfunction represents one of the least studied complications in thalassemic patients. Probably, it is due to the absence of pulmonary symptoms. There are few works in the literature, and contradictory results have been published. The aim of this study was to define the spirometric pattern and the possible causes of lung impairment by testing bronchoalveolar lavage (BAL) with pathological pulmonary function tests (PFTs). Furthermore, diffusion capacity tests for carbon monoxide corrected for hemoglobin value (Dco*) were performed. We studied 48 thalassemic patients (27 F and 21 M), with an age range from 8 to 23 years, divided into two groups on the basis of PFTs results. Thus, group A was formed by 16 patients with restrictive spirometric patterns of whom 14 had also reduced Dco* values and group B consisted of 32 patients with normal PFTs and Dco* values. Patients of group A underwent chest high-resolution computing tomography (CHRCT) and BAL whose fluid was analyzed by microbiologic and cytological assays. A pathological CHRCT picture was present in 8 patients. Nine out of 16 patients who accepted to undergo BAL had a chronological age greater than 17 years with a mean bone age of 13.9 years. BAL results showed lymphocyte alveolitis in 6 patients and a normal cytogram in 3, while alveolar iron-laden macrophages were present in 4 out of 6 patients with alveolitis and 2 out of 3 patients with normal cytogram. Moreover, all examined BAL fluids showed a normal CD4/CD8 ratio, while only 2 patients showed an altered serum CD4/CD8 ratio. We demonstrated the presence of (1) lung-restrictive syndrome in 16 of the oldest thalassemic patients; (2) lymphocyte alveolitis in 6 patients, and (3) a picture of interstitial fibrosis by CHRCT in 8 of them. All these data are suggestive of a diagnosis of interstitial lung disease secondary to thalassemia. BAL helped to identify the presence of alveolar iron-laden macrophages that represented a local defense mechanism against free iron. This latter finding therefore might be the primary cause of the lung impairment promoting an oxidative damage. Further studies are needed to investigate this hypothesis and therapeutical potentials.