RESUMO
BACKGROUND: We searched for any relationship between Chlamydophila pneumoniae, Mycoplasma pneumoniae, matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1) in aneurysmatic atherosclerotic lesions, and whether this relationship differed from that in atherosclerotic nonaneurysmatic lesions. METHODS: Twenty-eight tissue samples paired by age and sex were grouped as follows: group 1 included 14 nonaneurysmal atherosclerotic fragments obtained from abdominal aortas collected from necropsies; group 2 included 14 aneurysmatic atherosclerotic aortic fragments obtained from patients during corrective surgery. Immunohistochemistry reactions were evaluated for C pneumoniae, M pneumoniae, MMP-9, and TIMP-1 antigens. Both groups were compared using the Mann-Whitney test, and the correlations among variables were obtained using the Spearman correlation test. P ≤ 0.05 was considered statistically significant. RESULTS: C pneumoniae and M pneumoniae antigens were detected in 100% of cases. A higher amount of C pneumoniae (P = 0.005), M pneumoniae (P = 0.002), and MMP-9 (P = 0.021) was found in adventitia of group 2 with aneurysm. A positive correlation was found in the aneurysm group, as follows: intima C pneumoniae versus adventitia thickness (r = 0.70; P = 0.01), media C pneumoniae versus adventitia C pneumoniae (r = 0.75; P = 0.002), intima C pneumoniae versus media C pneumoniae (r = 0.8; P = 0.00), and adventitia C pneumoniae versus intima M pneumoniae (r = 0.54; P = 0.05); negative correlations were as follows: adventitia thickness and adventitia M pneumoniae (r = -0.65; P = 0.01), media MMP-9 and media thickness (r = -0.55; P = 0.04), TIMP-1 media versus adventitia C pneumoniae (r = -0.86; P = 0.00), and TIMP-1 media versus M pneumoniae intima (r = -0.67; P = 0.03). Nonaneurysmal atherosclerotic group 1 results are as follows: adventitia C pneumoniae versus TIMP-1 media (r = 0.75; P = 0.01) and media C pneumoniae and adventitia C pneumoniae (r = 0.59; P = 0.03). CONCLUSIONS: The present work favors a role for coinfection of both M pneumoniae and C pneumoniae in the development of aortic atherosclerotic aneurysm, with increased adventitial inflammation, inhibition of TIMP-1 activity, and increased collagen degradation.
Assuntos
Aneurisma Infectado/enzimologia , Aorta/enzimologia , Aneurisma Aórtico/enzimologia , Aterosclerose/enzimologia , Infecções por Chlamydophila/enzimologia , Coinfecção , Metaloproteinase 9 da Matriz/análise , Pneumonia por Mycoplasma/enzimologia , Inibidor Tecidual de Metaloproteinase-1/análise , Túnica Adventícia/enzimologia , Túnica Adventícia/microbiologia , Idoso , Aneurisma Infectado/diagnóstico , Aneurisma Infectado/microbiologia , Aneurisma Infectado/cirurgia , Aorta/microbiologia , Aorta/patologia , Aneurisma Aórtico/diagnóstico , Aneurisma Aórtico/microbiologia , Aneurisma Aórtico/cirurgia , Aterosclerose/diagnóstico , Infecções por Chlamydophila/diagnóstico , Infecções por Chlamydophila/microbiologia , Infecções por Chlamydophila/cirurgia , Chlamydophila pneumoniae/isolamento & purificação , Dilatação Patológica , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mycoplasma pneumoniae/isolamento & purificação , Pneumonia por Mycoplasma/diagnóstico , Pneumonia por Mycoplasma/microbiologia , Pneumonia por Mycoplasma/cirurgiaRESUMO
Mycoplasma pneumoniae is an important causative agent of respiratory infection in childhood. Although the infection caused by M. pneumoniae is classically described as benign, severe and life-threatening pulmonary and extrapulmonary complications can occur. This study describes the first case of septic shock related to M. pneumoniae in a child with necrotizing pneumonitis, severe encephalitis, and multiple organs involvement, with a favorable outcome after lobectomy and systemic corticosteroids.