Desempenho da quantificação de adenosina desaminase e determinação da relação lactato desidrogenase/adenosina desaminase para o diagnóstico de tuberculose pleural em crianças e adolescentes

Objective: To evaluate the accuracy of determining the adenosine deaminase (ADA) level, the 2’-deoxyadenosine/ADA ratio, and the LDH/ADA ratio in pleural fluid for the diagnosis of pleural tuberculosis (PT) in children and adolescents. Methods: This was a retrospective cross-sectional study conducted at a tertiary hospital in a high-tuberculosisincidence area, between 2001 and 2018. All patients with ADA in pleural fluid and a confirmed diagnosis of PT (cPT) or parapneumonic effusion (PPE) were included. Results: The cPT and PPE groups comprised 25 and 68 individuals, respectively. At a cutoff of 40 U/L, ADA measurement showed the following: sensitivity, 88%; specificity, 31%; positive predictive value (PPV), 32%; negative predictive value (NPV), 88%; and overall accuracy, 46%. The best cutoffs were an ADA level of 125 U/L, a 2’-deoxyadenosine/ ADA ratio of 0.5, and an LDH/ADA ratio of 8.3, with AUC of 0.67, 0.75, and 0.82, respectively. The sensitivity, specificity, PPV, NPV, and overall accuracy of the 125 U/L ADA cutoff were 84%, 65%, 47%, 92%, and 70%, respectively, compared with 79%, 79%, 59%, 91%, and 79%, respectively, for the 8.3 LDH/ADA ratio cutoff. Changing the LDH/ADA ratio cutoff to 3.0 increased the specificity to 98%. Conclusions: The ADA level and the 2’-deoxyadenosine/ADA ratio are not good biomarkers for the diagnosis of PT in pediatric patients. Determination of the LDH/ADA ratio provides the best overall accuracy for the diagnosis of PT in such patients.Objetivo: Avaliar a acurácia da determinação do nível de adenosina desaminase (ADA), da relação 2’-desoxiadenosina/ADA e da relação LDH/ADA no líquido pleural para o diagnóstico de tuberculose pleural (TP) em crianças e adolescentes. Métodos: Estudo transversal retrospectivo realizado em um hospital terciário em uma área de alta incidência de tuberculose entre 2001 e 2018. Todos os pacientes com determinação de ADA no líquido pleural e com diagnóstico confirmado de TP (TPc) ou de derrame parapneumônico (DPP) foram incluídos. Resultados: Os grupos TPc e DPP foram compostos por 25 e 68 indivíduos, respectivamente. Num ponto de corte de 40 U/L, a medida de ADA mostrou o seguinte: sensibilidade, 88%; especificidade, 31%; valor preditivo positivo (VPP), 32%; valor preditivo negativo (VPN), 88%; e acurácia geral, 46%. Os melhores pontos de corte foram ADA de 125 U/L, relação 2’-desoxiadenosina/ADA de 0,5 e relação LDH/ADA de 8,3, com ASC de 0,67, 0,75 e 0,82, respectivamente. A sensibilidade, especificidade, VPP, VPN e acurácia geral do ponto de corte de 125 U/L para ADA foram de 84%, 65%, 47%, 92% e 70%, respectivamente, em comparação com 79%, 79%, 59%, 91% e 79%, respectivamente, para o ponto de corte de 8,3 para a relação LDH/ADA. Ao alterar o ponto de corte da relação LDH/ADA para 3,0 a especificidade aumentou para 98%. Conclusões: O nível de ADA e a relação 2’-desoxiadenosina/ADA não são bons biomarcadores para o diagnóstico de PT em pacientes pediátricos. A determinação da relação LDH/ADA fornece a melhor acurácia geral para o diagnóstico de PT nesses pacientes

Evidence of methylphenidate effect on mitochondria, redox homeostasis, and inflammatory aspects : insights from animal studies

Methylphenidate (MPH) is a central nervous system (CNS) stimulant known for its effectiveness in the treatment of Attention Deficit Hyperactivity Disorder (ADHD), a neuropsychiatric condition that has a high incidence in childhood and affects behavior and cognition. However, the increase in its use among individuals who do not present all the diagnostic criteria for ADHD has become a serious public health problem since the neurological and psychiatric consequences of this unrestricted use are not widely known. In addition, since childhood is a critical period for the maturation of the CNS, the high prescription of MPH for preschool children also raises several concerns. This review brings new perspectives on how MPH (in different doses, routes of administration and ages) affects the CNS, focusing on animal studies that evaluated changes in mitochondrial (bioenergetics), redox balance and apoptosis, as well as inflammatory parameters. MPH alters brain energy homeostasis, increasing glucose consumption and impairing the activity of enzymes in the Krebs cycle and electron transport chain, as well as ATP levels and Na+,K+-ATPase activity. MPH induces oxidative stress, increasing the levels of reactive oxygen and nitrogen species and altering enzymatic and non-enzymatic antioxidant defenses, which, consequently, is related to damage to proteins, lipids, and DNA. Among the harmful effects of MPH, studies also demonstrate its ability to induce inflammation as well as alter the apoptosis pathway. It is important to highlight that age, treatment time, administration route, and dose are factors that can influence MPH effects. However, young animals seem to be more susceptible to damage caused by MPH. It is possible that changes in mitochondrial function and markers of status oxidative, apoptosis and inflammation may be exerting important mechanisms associated with MPH toxicity and, therefore, the unrestricted use of this drug can cause brain damage