Validation of an automated immune turbidimetric assay for serum gelsolin and its possible clinical utility in sepsis

J Clin Lab Anal. 2018 Mar;32(3):e22321. doi: 10.1002/jcla.22321. Epub 2017 Sep 5.

Abstract

Background: Studies showing the potential predictive value of the actin-binding protein gelsolin, in critically ill patients are scarce. Moreover, even up to now a rapid automated measurement of gelsolin has still remained a challenge. Therefore, we developed and validated an automated serum gelsolin immune turbidimetric assay for possible clinical use.

Methods: Validation of serum gelsolin assay was performed on a Cobas 8000/c502 analyzer (Roche) according to the second edition of Eurachem guidelines. Furthermore, we also studied the diagnostic value of serum gelsolin in sepsis when investigating sera of septic (n = 25), systemic inflammatory response syndrome (SIRS; n = 8) and control patients (n = 14). We compared our previously published Western blot data with those of the new turbidimetric assay.

Results: The sample volume was 7 μL and the assay time was 10 minutes. The detection limit was 0.72 mg/L, intra- and inter-assay imprecision remained in most cases less than 5% expressed as CV. Recovery was found to be 84.56%-93.52% and linearity study gave an appropriate correlation coefficient by linear regression analysis (r2 = .998). Septic patients exhibited lower (P = .015) first-day serum gelsolin levels than SIRS patients, which confirmed our previous Western blot results. The determined cut-off point for serum gelsolin was 14.05 mg/L (sensitivity: 75%; specificity: 60%) when investigating its diagnostic value in sepsis.

Conclusion: Based on the results, our immune turbidimetric measurement offers a rapid and accurate quantitation of gelsolin in human serum samples. Serum gelsolin seems a promising additional diagnostic marker of sepsis which has to be further investigated.

Keywords: automation; diagnostic marker; immune turbidimetry; sepsis; serum gelsolin.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Automation, Laboratory / methods*
  • Female
  • Gelsolin / blood*
  • Humans
  • Limit of Detection
  • Linear Models
  • Male
  • Middle Aged
  • Nephelometry and Turbidimetry / methods*
  • ROC Curve
  • Reproducibility of Results
  • Sepsis / blood*
  • Sepsis / diagnosis*

Substances

  • Gelsolin