Original scientific paper

https://doi.org/10.11613/BM.2020.020701

Long-term stability of clinically relevant chemistry analytes in pleural and peritoneal fluid

Lara Milevoj Kopcinovic orcid.org/0000-0003-0360-9148 ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Marija Brcic ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Alen Vrtaric ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Adriana Unic ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Marija Bozovic ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Nora Nikolac Gabaj ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Marijana Miler ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia
Jelena Culej ; Department of Clinical Chemistry, Sestre milosrdnice University Hospital Centre, Zagreb, Croatia

Abstract

Introduction: Our aim was to investigate the stability of clinically relevant analytes in pleural and peritoneal fluids stored in variable time periods and variable storage temperatures prior to analysis.
Materials and methods: Baseline total proteins (TP), albumin (ALB), lactate dehydrogenase (LD), cholesterol (CHOL), triglycerides (TRIG), creatinine (CREA), urea, glucose and amylase (AMY) were measured using standard methods in residual samples from 29 pleural and 12 peritoneal fluids referred to our laboratory. Aliquots were stored for 6 hours at room temperature (RT); 3, 7, 14 and 30 days at - 20°C. At the end of each storage period, all analytes were re-measured. Deviations were calculated and compared to stability limits (SL).
Results: Pleural fluid TP and CHOL did not differ in the observed storage periods (P = 0.265 and P = 0.170, respectively). Statistically significant
differences were found for ALB, LD, TRIG, CREA, urea, glucose and AMY. Peritoneal fluid TP, ALB, TRIG, urea and AMY were not statistically different after storage, contrary to LD, CHOL, CREA and glucose. Deviations for TP, ALB, CHOL, TRIG, CREA, urea and AMY in all storage periods tested for both serous fluids were within the SL. Deviations exceeding SL were observed for LD and glucose when stored for 3 and 7 days at - 20°C, respectively.
Conclusions: TP, ALB, CHOL, TRIG, CREA, urea and AMY are stable in serous samples stored up to 6 hours at RT and/or 30 days at - 20°C. Glucose is stable up to 6 hours at RT and 3 days at - 20°C. The stability of LD in is limited to 6 hours at RT.

Keywords

stability, pleural effusion; peritoneal effusion; preanalytical phase

Hrčak ID:

238904

URI

https://hrcak.srce.hr/238904

Publication date:

15.6.2020.

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