Serum levels of interleukin-6 in contacts of active pulmonary tuberculosis

• Main Authors: Fernando Henrique Azevedo Lopes (Author), Lívia Coelho de Assis (Author), Roberto da Justa Pires Neto (Author), Karine Paschoal Botelho (Author), Kélvia Miranda Sá (Author), Cristiane Cunha Frota (Author), José Walter Correia (Author), Max Victor Carioca Freitas (Author)
• Format: Book
• Published: Sociedade Brasileira de Patologia Clínica, 2013-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

INTRODUCTION: It is estimated that over two billion individuals are infected by Mycobacterium tuberculosis worldwide. Interleukin-6 (IL-6) is an important cytokine whose serum levels are commonly high in active pulmonary tuberculosis (TB). IL-6 screening in contacts of patients with TB may be useful to monitor the progress of the infectious process and to infer the risk of progression to active disease. OBJECTIVE: To evaluate the serum levels of interleukin-6 in contacts of patients with active pulmonary tuberculosis and to compare them with two other groups: a) patients affected by active pulmonary tuberculosis; b) non-contacts of tuberculosis. METHODS: Cross-sectional study with 15 contacts of patients with active pulmonary tuberculosis, selected according to the protocol recommended by the Ministry of Health. The serum levels of interleukin-6 were measured by Enzyme-linked immunosorbent assay (ELISA). The same test was also applied in the two comparison groups: 38 patients with active pulmonary tuberculosis (confirmed by clinical examination, X-rays of the chest and baciloscopy) and 63 non-contacts (healthy blood donors). RESULTS: In the contact group, the median IL-6 concentration was 1.7 pg/ml (0.96-4.8 pg/ml). For those affected by active pulmonary tuberculosis and non-contact individuals, these values corresponded to 4.3 pg/ml (0.5-24 pg/ml) and 0.5 pg/ml (0-2.8 pg/ml), respectively (p < 0.0001). CONCLUSION: Contacts of patients with active pulmonary tuberculosis had significantly higher IL-6 serum levels (3.4 times higher) in relation to non-contact individuals, but on a lower level (2.5 times lower) when compared to those affected by active disease.

Item Description

1678-4774
10.1590/S1676-24442013000600005