ABSTRACT
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.
INTRODUÇÃO: Estima-se em mais de dois bilhões o número de infectados pelo Mycobacterium tuberculosis no mundo. A interleucina-6 (IL-6) é uma importante citocina, cujos níveis séricos estão comumente elevados na tuberculose pulmonar ativa. A dosagem dessa citocina em contatos de pacientes com tuberculose pode ser útil para se acompanhar a evolução do processo infeccioso, bem como para inferir o risco de progressão da doença ativa. OBJETIVO: Avaliar os níveis séricos de IL-6 em contatos de pacientes com tuberculose pulmonar ativa e compará-los com os de dois outros grupos: a) pacientes acometidos por tuberculose pulmonar ativa; b) não contatos de tuberculose. MÉTODOS: Estudo transversal com 15 contatos de pacientes com tuberculose pulmonar ativa, selecionados de acordo com protocolo preconizado pelo Ministério da Saúde. Os níveis séricos de IL-6 foram mensurados por meio de ensaio imunoenzimático (ELISA). O mesmo ensaio também foi empregado nos dois grupos de comparação: 38 pacientes com tuberculose pulmonar ativa (confirmada por exame clínico, raios X de tórax e baciloscopia) e 63 não contatos, doadores saudáveis de sangue. RESULTADOS: Para o grupo de contatos, a mediana de concentração de IL-6 foi de 1,7 pg/ml (0,96-4,8 pg/ml); para os acometidos por tuberculose pulmonar ativa e indivíduos não contatos, esses valores foram 4,3 pg/ml (0-12 pg/ml) e 0,5 pg/ml (0-2,8 pg/ml), respectivamente (p < 0,0001). CONCLUSÃO: Contatos de pacientes com tuberculose pulmonar ativa apresentaram níveis séricos de IL-6 significativamente aumentados (3,4 vezes mais), em relação aos indivíduos não contatos, mas em um patamar inferior (2,5 vezes menos), quando comparados com os acometidos pela doença ativa.
ABSTRACT
OBJECTIVE: The aim of this study was to evaluate the impact of iron overload on the profile of interleukin-10 levels, biochemical parameters and oxidative stress in sickle cell anemia patients. METHODS: A cross-sectional study was performed of 30 patients with molecular diagnosis of sickle cell anemia. Patients were stratified into two groups, according to the presence of iron overload: Iron overload (n = 15) and Non-iron overload (n = 15). Biochemical analyses were performed utilizing the Wiener CM 200 automatic analyzer. The interleukin-10 level was measured by capture ELISA using the BD OptEIAT commercial kit. Oxidative stress parameters were determined by spectrophotometry. Statistical analysis was performed using GraphPad Prism software (version 5.0) and statistical significance was established for p-values < 0.05 in all analyses. RESULTS: Biochemical analysis revealed significant elevations in the levels of uric acid, triglycerides, very low-density lipoprotein (VLDL), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), urea and creatinine in the Iron overload Group compared to the Non-iron overload Group and significant decreases in the high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Ferritin levels correlated positively with uric acid concentrations (p-value < 0.05). The Iron overload Group showed lower interleukin-10 levels and catalase activity and higher nitrite and malondialdehyde levels compared with the Non-iron overload Group. CONCLUSION: The results of this study are important to develop further consistent studies that evaluate the effect of iron overload on the inflammatory profile and oxidative stress of patients with sickle cell anemia.