Predictive value of serum gelsolin and Gc globulin in sepsis - a pilot study

BACKGROUND

Simultaneous determination of the two main actin scavenger proteins in sepsis has not been investigated until now. In our pilot study, we elucidated the predictive values of Gc globulin and gelsolin (GSN) in sepsis by comparing them to classic laboratory and clinical parameters.

METHODS

A 5-day follow-up was performed, including 46 septic patients, 28 non-septic patients and 35 outpatients as controls. Serum Gc globulin and GSN levels were determined by automated immune turbidimetric assay on a Cobas 8000/c502 analyzer. Patients were retrospectively categorized according to the sepsis-3 definitions, and 14-day mortality was also investigated.

RESULTS

First-day GSN also differentiated sepsis from non-sepsis (AUC: 0.88) similarly to C-reactive protein (AUC: 0.80) but was slightly inferior to procalcitonin (PCT) (AUC: 0.98) with a cutoff value of GSN at 22.29 mg/L (sensitivity: 83.3%; specificity: 86.2%). Only first-day SOFA scores (0.88) and GSN (0.71) distinguished septic survivors from non-survivors, whereas lactate (0.99), Gc globulin (0.76) and mean arterial pressure (MAP) (0.74) discriminated septic shock from sepsis. Logistic regression analyses revealed SOFA scores and GSN being significant factors regarding 14-day mortality. First-day GSN levels were higher (p<0.05) in septic survivors than in non-survivors. Gc globulin levels remained higher (p<0.01) in sepsis when compared with septic shock during the follow-up period.

CONCLUSIONS

Both serum GSN and Gc globulin may have predictive values in sepsis. Considering the small sample size of our study, further measurements are needed to evaluate our results. Measurement of Gc globulin and GSN maybe useful in assessment of sepsis severity and in therapeutic decision-making.

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

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.