CD64 expression on neutrophils as a potential biomarker for bacterial infection in ascitic fluid of cirrhotic patients

Autores de IDIVAL

• Elena González López

  Autor

• Aitor Odriozola Herran

  Autor

• Mónica Renuncio García

  Autor

• Adriel Antonio Roa Bautista

  Autor

• Angela Anton Rodriguez

  Autor

• Alejandra Comins Boo

  Autor

• Juan Irure Ventura

  Autor

• 

  Ángela María Puente Sánchez

  Autor

• 

  Marcos López Hoyos

  Autor

• 

  José Ignacio Fortea Ormaechea

  Autor

• 

  David San Segundo Arribas

  Autor

Unidades

• INMUNOPATOLOGÍA

  

  Investigador Corresponsable

  Ricardo Blanco Alonso

• INVESTIGACIÓN CLÍNICA Y TRASLACIONAL EN ENFERMEDADES DIGESTIVAS

  

  Investigador Responsable

  José Ignacio Fortea Ormaechea

Abstract

BackgroundCD64 expression on neutrophils surface (CD64N) by flow cytometry has been validated as a rapid biomarker for bacterial infections in both peripheral blood and other biological fluids. Ascites is a common complication in cirrhotic patients that a variety of factors can cause, including bacterial infections. Manual counting of polymorphonuclear (PMN) cells in ascitic fluid and microbiologic culture are essential for its diagnosis. We aimed to validate the determination of CD64N by flow cytometry in ascitic fluid and assess its potential usefulness in the rapid identification of bacterial infections.Materials and methodsA prospective unicentre study was conducted. Flow cytometry was used to analyse the expression of CD64N in 77 ascitic fluid samples from the initial paracentesis of 60 cirrhotic patients in different admission episodes from November 2021 to December 2022.ResultsSeventeen samples were diagnosed with bacterial infection based on a positive microbiologic culture or by PMN count (>250 PMN/mm(3) in ascitic fluid). The median of CD64N MFI was significantly increased in the bacterial infection group (3690.5 MFI [1635.23-6521.18] vs. 1105.9 MFI [737.3-2048.2], p < 0.001). The CD64 MFI ratio of granulocytes to lymphocytes was elevated in the bacterial infection group (13.06 [6.38-24.58] vs. 5.01 [3.38-7.36], p < 0.001). A CD64N ratio higher than 9.9 identified those patients with bacterial infection with 70.6 and 86.7% sensitivity and specificity, with an area under the curve (AUC) of 79.4%.ConclusionThe CD64N determined by flow cytometry on ascitic fluid could help quickly identify bacterial infections in ascites patients, allowing early antibiotic treatment.

Keywords

• Bacterial infection; CD64 expression; ascitic fluid; flow cytometry