Validity of plasma collection cards for ferritin assessment-A proof-of-concept study

Iron depletion is common around the world and among certain risk groups in developed countries. The overall purpose was to test the suitability of a novel plasma collection card for minimally invasive iron status assessment.

Twenty participants (10 f/10 m) participated in this cross-sectional study. Ferritin and hemoglobin were measured from blood collected from a forearm vein, serving as reference method. Blood was also collected from the fingertip using the Noviplex^TM Plasma Prep Card as well as capillary collection tubes.

There was substantial concordance between ferritin measured from samples collected via Noviplex^TM and venous ferritin (concordance correlation coefficient (CCC) = 0.96) with a mean bias of -0.8 ng/mL. Storing Noviplex^TM cards at room temperature for 2 weeks resulted in slightly lower but good concordance when compared to venous ferritin (CCC = 0.95). Capillary hemoglobin (CCC = 0.42) and hematocrit (CCC = 0.25) were in poor agreement with venous data.

Noviplex^TM cards offer a suitable alternative for a minimally invasive ferritin screening in the field when compared to capillary collection tubes. Despite overall substantial concordance with the reference method, findings indicative of iron status abnormalities should be confirmed in venous samples.