CAN PLASMA OR SERUM BE USED INTERCHANGEABLY FOR DIFFERENT IMMUNOCHEMICAL ANALYTES?

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Barlak Keti D., Muhtaroğlu S.

XXXI National Congress of The Turkish Biochemical Society 2020, Antalya, Türkiye, 18 - 20 Aralık 2020, cilt.45, sa.60, ss.38

  • Yayın Türü: Bildiri / Özet Bildiri
  • Cilt numarası: 45
  • Basıldığı Şehir: Antalya
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.38
  • Erciyes Üniversitesi Adresli: Evet

Özet

OP-060

CAN PLASMA OR SERUM BE USED INTERCHANGEABLY FOR DIFFERENT IMMUNOCHEMICAL ANALYTES?

Didem Barlak Keti, Sabahattin Muhtaroglu Department of Medical Biochemistry, Erciyes University, Kayseri, Turkey

OBJECTIVES: Studies revealing the difference in plasma and serum test results for immunochemical analytes are limited and the results are also contradictory. The aim of this study was to evaluate whether there is a difference between serum and plasma for 10 immunochemical analytes. MATERIALS and METHODS: Total of 30 healthy volunteers were included in the study. Blood samples were collected in clot-activator with gel (Vacuette) and containing lithium heparin tubes with barrier (Barricor). Serum and plasma were obtained by centrifugation at 2000 g for 10 minutes. Hemolysis index was lower than 20 in serum and plasma samples. Paired t test was used for statistical analysis. Bias% results were compared with the desirable specification (B%) obtained from the Ricos database for clinically significant. Vitamin B12 (B12), ferritin, folate, free triiodothyronine (FT3), free thyroxine (FT4), insulin, ProBNP, parathyroid hormone (PTH), thyroid stimulating hormone (TSH) and vitamin D levels analysed on a Roche COBAS 8000 device.

RESULTS: There was a statistically significant difference for B12, ferritin, folate, insulin, proBNP, PTH, vitamin D between serum and plasma. Only, plasma PTH levels were clinically significant higher than serum. PTH levels were stable up to 8 hours at room temperature in plasma with lithium heparin. However, insulin levels remained stable up to 8 hours at room temperature in serum.

CONCLUSIONS: Plasma cannot be used instead of serum for PTH analysis. Therefore serum reference range is not suitable for this analyte. Unlike insulin, PTH levels are more stable in plasma with lithium heparin at room temperature.

Keywords: Plasma, Serum, Lithium Heparin, Parathyroid Hormone, Insulin