Usefulness of biomarkers on infection management: with or without them?

Infectious diseases are disorders caused by many different microorganisms that produce clinical conditions with a wide variation in patient-rated symptoms and severity. Therefore, different diagnostic and prognostic tools are needed to help make the most accurate decisions at each moment of patient´s care with suspected infection. This mini review will analyse how some biomarkers reduce the level of uncertainty in the making decision process at some phases of sepsis, including prompt identification of septic patients, early initiation of empiric broad-spectrum antimicrobials, regimen and duration.

Cistatina C como marcador precoz de lesión renal aguda en el shock séptico / Cystatin C as an early marker of acute kidney injury in septic shock

Objetivo: Describir la utilidad de la determinación de la concentración plasmática de cistatinaC en el diagnóstico precoz de la lesión renal aguda en el shock séptico. Pacientes y métodos: Serie prospectiva de 50 pacientes ingresados en una unidad de cuidados intensivos con shock séptico y creatinina plasmática <2mg/dl. Seguimiento clínico y analítico con determinaciones de cistatinaC, urea y creatinina plasmáticas desde el diagnóstico del shock séptico hasta 5días más tarde. Su gravedad se valoró con la escala RIFLE. Resultados: Veinte pacientes (40%) desarrollaron lesión renal aguda: 8 (16%) RIFLE «R», 5 (10%) RIFLE «I» y 7 (14%) RIFLE «F». Todos los RIFLE «F» precisaron depuración renal extracorpórea. Fallecieron 18 pacientes (36%); de ellos 8 (20%) habían desarrollado lesión renal aguda en su evolución. Hubo una correlación pobre entre creatinina y cistatinaC plasmáticas (r=0,501; p=0,001), que desaparecía cuando se alcanzaba cualquier grado de deterioro renal en la escala RIFLE. La cistatinaC se elevaba antes e identificaba mejor que la creatinina y la urea a aquellos pacientes que iban a desarrollar un deterioro severo de su función renal (RIFLE «F») y sus valores iniciales se relacionaban con la mortalidad a los 30días (OR=1,16; IC95%: 0,03-0,85). Conclusiones: En los pacientes que desarrollan lesión renal aguda séptica la cistatinaC plasmática se incrementa antes que los marcadores clásicos de función renal. Además constituye un biomarcador de severidad que se correlaciona con la evolución a RIFLE «F», la necesidad depuración extrarrenal y la mortalidad. Esta precocidad puede ser útil para instaurar medidas que eviten la progresión de la disfunción renal (AU)

Objective: To describe the utility of determining plasma cystatinC concentrations in the diagnosis of acute incident kidney injury in septic shock. Patients and methods: Prospective series of 50 patients with septic shock and plasma creatinine levels <2mg/dL hospitalized in an intensive care unit. Clinical and laboratory follow-ups were conducted, with measurements of cystatinC, urea and plasma creatinine levels from the diagnosis of septic shock to 5days later. The severity of the septic shock was assessed with the RIFLE scale. Results: Twenty patients (40%) developed acute kidney injury: 8 (16%) were categorized as RIFLE-R, 5 (10%) as RIFLE-I and 7 (14%) as RIFLE-F. All patients categorized as RIFLE-F required extracorporeal renal clearance. Eighteen (36%) patients died, 8 (20%) of whom had developed acute kidney injury in their evolution. There was poor correlation between plasma creatinine and cystatin C levels (r=.501; P=.001), which disappeared upon reaching any degree of renal impairment on the RIFLE scale. CystatinC levels increased earlier and were better able to identify patients who would develop serious renal function impairment (RIFLE-F) than creatinine and urea levels. The initial cystatinC levels were related to mortality at 30days (OR=1.16; 95%CI: 03-.85). Conclusions: For patients who developed acute septic kidney injury, the plasma cystatinC levels increased before the classical markers of renal function. CystatinC also constitutes a severity biomarker that correlates with progression to RIFLE-F, the need for extrarenal clearance and, ultimately, mortality. This precocity could be useful for starting measures that prevent the progression of renal dysfunction (AU)

Cystatin C as an early marker of acute kidney injury in septic shock. / Cistatina C como marcador precoz de lesión renal aguda en el shock séptico.

OBJECTIVE: To describe the utility of determining plasma cystatinC concentrations in the diagnosis of acute incident kidney injury in septic shock. PATIENTS AND METHODS: Prospective series of 50 patients with septic shock and plasma creatinine levels <2mg/dL hospitalized in an intensive care unit. Clinical and laboratory follow-ups were conducted, with measurements of cystatinC, urea and plasma creatinine levels from the diagnosis of septic shock to 5days later. The severity of the septic shock was assessed with the RIFLE scale. RESULTS: Twenty patients (40%) developed acute kidney injury: 8 (16%) were categorized as RIFLE-R, 5 (10%) as RIFLE-I and 7 (14%) as RIFLE-F. All patients categorized as RIFLE-F required extracorporeal renal clearance. Eighteen (36%) patients died, 8 (20%) of whom had developed acute kidney injury in their evolution. There was poor correlation between plasma creatinine and cystatin C levels (r=.501; P=.001), which disappeared upon reaching any degree of renal impairment on the RIFLE scale. CystatinC levels increased earlier and were better able to identify patients who would develop serious renal function impairment (RIFLE-F) than creatinine and urea levels. The initial cystatinC levels were related to mortality at 30days (OR=1.16; 95%CI: 03-.85). CONCLUSIONS: For patients who developed acute septic kidney injury, the plasma cystatinC levels increased before the classical markers of renal function. CystatinC also constitutes a severity biomarker that correlates with progression to RIFLE-F, the need for extrarenal clearance and, ultimately, mortality. This precocity could be useful for starting measures that prevent the progression of renal dysfunction.