Deactivation of alveolar macrophages in neutropenic acute respiratory distress syndrome (ARDS) in children with hematologic malignancy

Abstract

Objective To study the alveolar macrophages (AM) activation in neutropenic ARDS in children with hematologic malignancy. Methods Thirteen patients of ARDS were prospectively enrolled into the study and divided into two groups,neutropenic (5 cases) and nonneutropenic (8 cases). Bronchoalveolar lavage fluid (BALF) samples were analyzed for differential and total cell counts, and alveolar activation marker expression (HLA-DR) was determined. Results In neutropenic patients,the BALF total cell count and the macrophage absolute count were significantly lower compared to those in nonneutropenic group ((62. 6 ±9. 6)/μl vs ( 124. 0 ± 6. 7)/μl,P ＜ 0. 01 and (40. 8 ±4. 3)/μl vs (67. 6 ± 10. 7)/μl,P ＜ 0. 01,respectively). As compared with the nonneutropenic group, the percentage of AM in neutropenic patients was significantly higher (65.9% ±9. 0% vs 54. 6% ± 8. 7% ,P ＜0. 05) ,the mean percentage of AM HLA-DR expression was significantly lower (35. 3% ± 5.8% vs 62. 2% ± 5. 8%, P ＜ 0. 01 ). Conclusion These results suggest an alveolar hypocellularity and a deactivation of AM in neutropenic ARDS in children with hematologic malignancy. Key words: Alveolar macrophage; Acute respiratory distress syndrome; Neutropenia; Human leukocyte antigen-DR