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Inicio Neurología (English Edition) Utility of biomarkers to predict bacterial meningitis in elderly patients
Journal Information
Vol. 32. Issue 3.
Pages 192-193 (April 2017)
Vol. 32. Issue 3.
Pages 192-193 (April 2017)
Letter to the Editor
DOI: 10.1016/j.nrleng.2015.05.012
Open Access
Utility of biomarkers to predict bacterial meningitis in elderly patients
Utilidad de los biomarcadores para predecir meningitis bacterianas en los pacientes ancianos
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T. Martínez-Marotoa, M. Santana-Moralesb, E. Valente-Rodrígueza, R. Parejo-Migueza,
Corresponding author
rapami.pajupa@wanadoo.es

Corresponding author.
a Servicio de Geriatría, Complejo Hospitalario de Toledo, Toledo, Spain
b Servicio de Análisis Clínicos y Bioquímica, Complejo Hospitalario de Toledo, Toledo, Spain
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Dear Editor:

It was with great interest that we read the study by Morales Casado et al.1 recently published in Neurología and addressing the utility of biomarkers of infection and inflammation (BII; procalcitonin [PCT] and C-reactive protein [CRP]) for predicting bacterial meningitis in the emergency department. Although we agree that both BII have a good predictive ability for detecting bacterial meningitis and differentiating bacterial from viral meningitis,2 we would like to add further comments regarding the subgroup of patients older than 75. The utility of BII, particularly CRP, in elderly patients is still controversial due to immunosenescence, a process that alters immune response and especially inflammatory response. Elderly patients show higher levels of proinflammatory cytokines (for example, IL-6 and IL-8) against bacterial infection. Likewise, CRP determinations in this population yield a higher rate of false-positive results and have lower sensitivity and specificity for differentiating bacterial from viral infections.2,3

As the authors pointed out, although acute meningitis is not ranked among the most frequent infections in the emergency department,4 it is one of the most severe, as well as one of the types of infection most frequently leading to severe sepsis and septic shock.5 In the past few years, the incidence of infections in emergency departments has increased significantly (P<.001) among the elderly (31.7% vs 24.8%).4 Clinical severity and mortality in this subgroup have also increased.6 In this population, suspecting and confirming bacterial meningitis is especially important given the severity of this process and the largely non-specific, highly variable symptoms associated with infectious processes.3 This results in delayed diagnosis in these patients and leads to administering unnecessary antimicrobial drugs in more than 50% of the cases.7 In the study by Morales Casado et al.,1 PCT achieved an excellent diagnostic power for detecting bacterial meningitis, with an area under the ROC curve (AUC) of 0.99, 94% sensitivity, and 100% specificity for a cut-off point of 0.74ng/mL. CRP was also found to have a good diagnostic power, with an AUC of 0.91; however the cut-off point was higher (90mg/L) and both sensitivity (67%) and specificity (86%) were lower. We hypothesise that CRP results may be overestimated in this study and reflect the mean age in their sample (44 years). Published evidence shows that: (1) 50-65% of all patients older than 75 have high CRP levels in the absence of underlying infections (false positives)2,8 upon arriving at the emergency department, and (2) the diagnostic power of CRP decreases in older populations, whereas that of PCT remains the same, as in cases of bacteraemia (including cases of associated bacterial meningitis).9 We therefore feel that CRP determinations must be interpreted with caution in elderly patients, especially in severe cases such as suspected bacterial meningitis. Over 50% of the patients with fever in emergency departments undergo CRP tests (but not PCT tests)10 to differentiate between viral and bacterial meningitis, and more than 40% of all infectious processes in emergency departments affect elderly patients. The above suggests that isolated CRP measurements have a very limited diagnostic power in the emergency department for confirming or ruling out a bacterial aetiology of acute meningitis (unlike PCT). We need specific studies analysing the diagnostic power of BII by age group to confirm that the diagnostic ability of CRP is similar to that of PCT in children, decreases in adults, and is limited in elderly patients.2

Conflicts of interest

The authors have no conflicts of interest to declare.

References
[1]
M.I. Morales Casado, F. Moreno Alonso, A.L. Juárez Belaunde, E. Heredero Gálvez, O. Talavera Encinas, A. Julián-Jiménez.
Capacidad de la procalcitonina para predecir meningitis bacterianas en el servicio de urgencias.
[2]
A. Julián-Jiménez, F.J. Candel-González, J. González del Castillo.
Utilidad de los biomarcadores de inflamación e infección en los servicios de urgencias.
Enferm Infecc Microbiol Clin, 32 (2014), pp. 177-190
[3]
S.M. Opal, T.D. Girard, E.W. Ely.
The immunopathogenesis of sepsis in elderly.
Clin Infect Dis, 41 (2005), pp. 5504-5512
[4]
M. Martínez Ortiz de Zárate, J. González del Castillo, A. Julián-Jiménez, P. Piñera Salmerón, F. Llopis Roca, J.M. Guardiola Tey, en representación del grupo INFURG-SEMES.
Estudio INFURG-SEMES: Epidemiología de las Infecciones en los Servicios de Urgencias Hospitalarios y evolución en la última década.
Emergencias, 25 (2013), pp. 368-378
[5]
F. González Martínez, A. Huete Hurtado, L. Mercedes Kerlin, R.E. Zamora Peña.
Estudio prospectivo y multicéntrico de la epidemiología de las infecciones del sistema nervioso central (meningitis y encefalitis) en los servicios de urgencias hospitalarios.
[6]
M. Ruiz-Ramos, F.J. García-León, J.L. López-Campos.
Características demográficas de la mortalidad en los servicios de urgencias hospitalarios de Andalucía.
Emergencias, 26 (2014), pp. 109-113
[7]
D. Nicolás, E. Monclús, A. de Andrés, M. Sánchez, M. Ortega.
Características de la prescripción de antibióticos en un servicio de urgencias de un hospital de tercer nivel.
Emergencias, 26 (2014), pp. 367-370
[8]
A. Julián-Jiménez, F. Moreno-Alonso, M.I. Morales-Casado, D. Muñoz-López.
Utilidad de procalcitonina y proteína C reactiva para predecir bacteriemia en el paciente anciano o con inmunodepresión.
Enferm Infecc Microbiol Clin, 33 (2015), pp. 366-367
[9]
C.C. Lai, S.Y. Chen, C.Y. Wang, J.Y. Wang, C.P. Su, C.H. Liao, et al.
Diagnostic value of procalcitonin for bacterial infection in elderly patients in the emergency department.
J Am Geriatr Soc, 58 (2010), pp. 518-522
[10]
M. Salinas, M. López-Garrido, J. Uris, C. Leiva-Salinas.
Variabilidad en la oferta y en la solicitud de determinaciones de laboratorio en pacientes de servicios de urgencias hospitalarios.
Emergencias, 26 (2014), pp. 450-458

Please cite this article as: Martínez-Maroto T, Santana-Morales M, Valente-Rodríguez E, Parejo-Miguez R. Utilidad de los biomarcadores para predecir meningitis bacterianas en los pacientes ancianos. Neurología. 2017;32:192–193.

Copyright © 2015. Sociedad Española de Neurología
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