Specificity and sensitivity of hemosiderin-laden macrophages in routine bronchoalveolar lavage in children

Abstract

Context: The presence of iron or hemosiderin in macrophages obtained in routine bronchoalveolar lavage is considered crucial in the diagnosis of the clinical syndrome of hemosiderosis. However, there do not appear to be any data on the sensitivity and specificity of the finding of hemosiderin-laden macrophages (HLMs) in bronchoalveolar lavage in children.

Objective: To review data from bronchoalveolar lavage studies done in children to correlate the presence of HLMs with pneumonia and hemosiderosis and to determine what proportion of HLMs has the optimal sensitivity and specificity for the diagnosis of hemosiderosis.

Design: One hundred ten bronchoalveolar lavage specimens obtained via flexible bronchoscopy were reviewed retrospectively. The data collected for demographics, indication for the bronchoscopy, diagnosis of pneumonia, anemia, and bronchoscopy and bronchoalveolar lavage findings were compared between patients diagnosed with hemosiderosis and those diagnosed with other diseases.

Results: Six patients were diagnosed with hemosiderosis by clinical findings, lung biopsy, or autopsy. There were no statistical differences in pneumonia (P > .99), anemia (P > .99), or coughing (P = .08) between patients with hemosiderosis and other patients. Hemoptysis was the only symptom that was significantly different between the 2 groups (P = .04). The mean HLM index for patients with hemosiderosis was 56% +/- 16.17% and for other patients, 7.5% +/- 10.74% (P < .001). A HLM index of 35% gave a sensitivity of 1% and a specificity of .96%.

Conclusions: These results confirm a strong association between HLM index and diagnosis of hemosiderosis in a pediatric population. Availability of this HLM index will result in accurate and timely diagnosis of pulmonary hemosiderosis, which may influence treatment and long-term prognosis.