Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

BACKGROUND: Mild hemolysis occurs physiologically in neonates, but more severe forms can lead to life-threatening anemia. Newborns in developing regions are particularly at-risk due to the higher incidence of triggers (protozoan infections, sepsis, certain genetic traits). In advanced healthcare facilities, hemolysis is monitored indirectly using resource-intensive methods that probe downstream ramifications. These approaches could potentially delay critical decisions in early-life care, and are not suitable for point-of-care testing. Rapid and cost-effective testing could be based on detecting red blood cell (RBC)-specific proteins, such as carbonic anhydrase I (CAI), in accessible fluids (e.g., urine). METHODS: Urine was collected from 26 full-term male neonates and analyzed for CAI using immunoassays (ELISA, western blot) and proteomics (mass spectrometry). The cohort included a range of hemolytic states, including admissions with infection, ABO incompatibility, and receiving phototherapy. Data were paired with hemoglobin, serum bilirubin (SBR), and C-reactive protein (CRP) measurements. RESULTS: Urine from a control cohort (CRP < 20 mg/L, SBR < 125µmol/L) had no detectable CAI, in line with results from healthy adults. CAI excretion was elevated in neonates with raised SBR (>125 µmol/L), including those qualifying for phototherapy. Newborns with low SBR (<125 µmol/L) but elevated CRP (>20 mg/L) produced urine with strong CAI immunoreactivity. Proteomics showed that CAI was the most abundant RBC-specific protein in CAI-immunopositive samples, and did not associate with other RBC-derived peptides, indicating an intravascular hemolytic source followed by CAI-selective excretion. CONCLUSIONS: CAI is a direct biomarker of intravascular hemolysis that can be measured routinely in urine using non-invasive methods under minimal-laboratory conditions.

Original publication




Journal article


J Appl Lab Med

Publication Date





921 - 934