RESUMO
Monocyte chemotactic protein-4 [MCP-4/CCL-13] is a potent chemoattractant to eosinophils, monocytes and lymphocytes. We aimed to investigate MCP-4 and its CC chemokine receptor 3 [CCR3] expression on cells of induced sputum during acute asthma exacerbation. Immunohistochemistry was used to assess MCP-4 and CCR3 expression on induced sputum cells of 30 children during asthma exacerbation and 20 healthy matched controls. Patients were divided into three groups according to exacerbation severity; mild, moderate and severe [n = 10 for each]. Patients were followed until quiescence, when sputum was re-examined. MCP-4 and CCR3 were expressed on eosinophils and monocytes. Lymphocytes expressed only MCP-4. The percentages of sputum total cells, eosinophils and lymphocytes expressing MCP-4 and/or CCR3 were significantly higher during asthma exacerbation than in controls and negatively correlated with peak expiratory flow rate, whereas that of monocytes was not. The percentages of sputum total cells, eosinophils, monocytes and lymphocytes expressing MCP-4; and total cells and eosinophils expressing CCR3 were significantly higher in patients with severe than those with mild and moderate exacerbations. When patients were followed till remission, the percentages of sputum cells expressing MCP-4 and CCR3 decreased. Sputum eosinophil percentage correlated positively with the percentage of eosinophils expressing MCP-4 and CCR3 [r = 0.69, p < 0.0001; r = 0.62, p < 0.001, respectively]. The percentage of sputum eosinophils expressing MCP-4 correlated positively with that of cells expressing CCR3 [r = 0.95, p < 0.0001]. The expression of MCP-4 and CCR3 on sputum cells increases during acute asthma exacerbation and this increase correlates with exacerbation severity, and it decreases during remission. Modification of their expression could be a potential target for asthma therapy