Dried blood spot measurement of pregnancy-associated plasma protein A (PAPP-A) and free β-subunit of human chorionic gonadotropin (β-hCG) from a low-resource setting

Prenat Diagn. 2015 Jun;35(6):592-7. doi: 10.1002/pd.4578. Epub 2015 Apr 1.

Abstract

Objectives: The objectives of the article is to compare pregnancy-associated plasma protein A (PAPP-A) and free β-subunit of human chorionic gonadotropin (β-hCG) concentrations in dried blood spots (DBSs) with serum of samples obtained from a public hospital in a low-resource setting and to evaluate their stability.

Methods: Serum and DBS samples were obtained by venipuncture and finger prick from 50 pregnant participants in a cohort study in a public hospital in Accra, Ghana. PAPP-A and β-hCG concentrations from serum and DBS were measured with an AutoDELFIA® (PerkinElmer, PerkinElmer, Turku, Finland) automatic immunoassay. Correlation and Passing-Bablok regression analyses were performed to compare marker levels.

Results: High correlation (>0.9) was observed for PAPP-A and β-hCG levels between various sampling techniques. The β-hCG concentration was stable between DBS and serum, PAPP-A concentration consistently lower in DBS.

Conclusion: Our findings suggest that β-hCG can be reliably collected from DBS in low-resource tropical settings. The exact conditions of the clinical workflow necessary for reliable PAPP-A measurement in these settings need to be further developed in the future. These findings could have implications for prenatal screening programs feasibility in low-income and middle-income countries, as DBS provides an alternative minimally invasive sampling method, with advantages in sampling technique, stability, logistics, and potential application in low-resource settings.

MeSH terms

  • Adult
  • Aneuploidy*
  • Chorionic Gonadotropin, beta Subunit, Human / analysis
  • Chorionic Gonadotropin, beta Subunit, Human / blood*
  • Cohort Studies
  • Cross-Sectional Studies
  • Dried Blood Spot Testing*
  • Female
  • Ghana
  • Health Resources
  • Humans
  • Pregnancy
  • Pregnancy Trimester, First
  • Pregnancy Trimester, Second
  • Pregnancy-Associated Plasma Protein-A / analysis
  • Pregnancy-Associated Plasma Protein-A / metabolism*
  • Prenatal Diagnosis
  • Young Adult

Substances

  • Chorionic Gonadotropin, beta Subunit, Human
  • Pregnancy-Associated Plasma Protein-A
  • PAPPA protein, human