Spurious undetectable albumin due to hemodialysis catheter lock contamination.
Ahmet Namlı, Hasan Alp Turgut, Mehmet Şeneş
✦ AI-curated · Sources linked
Case in brief
A clinically stable 46-year-old man receiving maintenance hemodialysis had a routine albumin result below the assay’s analytical measuring range (<2 g/L), despite no clinical signs of severe hypoalbuminemia. The sample had been drawn through a tunneled catheter without first discarding the heparin lock solution. Analytical error was considered unlikely because repeat measurement was unchanged and internal quality control was acceptable. After an appropriate discard volume, a repeat sample showed albumin of 42 g/L, supporting heparin-lock contamination as the explanation for the spurious result.
What made this case unusual
The catheter lock solution produced an apparently extreme albumin result (<2 g/L) in a clinically stable patient; the BCG method is susceptible to dose-dependent negative interference from heparin.
Diagnostic / clinical pearl
When an unexpectedly low albumin is measured by the BCG method in a sample drawn through a hemodialysis catheter, consider heparin-lock contamination and check whether the appropriate discard volume was used.
Why it matters
A contaminated sample can yield an analytically uninterpretable result; the report emphasizes adherence to evidence-based discard-volume protocols in dialysis units.