title: Blood volume and red cell mass in children with moderate and severe malaria measured by chromium-53 dilution and gas chromatography/mass spectrometric analysis.
abstract: Understanding blood volume changes in children with malaria is important for managing fluid status. Traditionally, blood/red cell volume measurements have used radioactive chromium isotopes. We applied an alternative approach, using non-radioactive chromium-53 labelling and mass spectrometry to investigate red cell volume (RCV) in Gabonese children with malaria. Nineteen children with malaria participated (10 severe, 9 moderately severe; ages 15 months to 7 years). Blood labelled with (53)Cr-chromate ex vivo was re-injected, then sampled 30 min later. Pre- and post-injection (53)Cr content were measured by gas chromatography/electron ionisation mass spectrometry of the chromium-trifluoroacetylacetone (TFA) chelate, calibrated against (50)Cr standards. Blood and red cell volumes were calculated from isotopic dilution in 15 of 19 children (in four, insufficient signal mitigated analysis). In this small pilot study, there were no significant differences between moderate and severe cases. Including all subjects, the mean RCV was reduced compared with predicted values (184 vs. 269 mL; p = 0.016) but blood volume, 71 +/- 33 mL/kg (normalised for weight), was close to predicted, approximately 77 mL/kg, commensurate with reduced haematocrit. Blood lactate concentration correlated negatively with RCV/weight (r = -0.56, p = 0.028), consistent with anaemia. In one case, sequential samples over 42 days gave an estimated rate of (53)Cr disappearance of 1.4%/day (equivalent half-life: 70 days). (53)Cr-labelling of red cells may be used to estimate blood and red cell volumes and can be used as an investigative tool in situations such as childhood diseases and resource-constrained settings. Although the red cell mass is depleted in malaria, the blood volume appears relatively well preserved.
authors: Division of Cellular and Molecular Medicine, Centre for Infection, St. George's Hospital Medical School, London SW17 0RE, UK. macallan@sgul.ac.uk
authors: Derek C
authors: DC
authors: Macallan
authors: Daniel A
authors: DA
authors: Abaye
authors: Simone
authors: S
authors: Dottin
authors: Myriam
authors: M
authors: Onanga
authors: Maryvonne
authors: M
authors: Kombila
authors: Arnaud
authors: A
authors: Dzeing-Ella
authors: Peter G
authors: PG
authors: Kremsner
authors: Sanjeev
authors: S
authors: Krishna
authors: Timothy
authors: T
authors: Planche
mesh_terms: D001810:Blood Volume; D002648:Child; D002675:Child, Preschool; D002859:Chromium Isotopes / Q000032:analysis* / Q000378:metabolism; D015331:Cohort Studies; D004911:Erythrocyte Volume; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D007223:Infant; D008288:Malaria / Q000097:blood* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D008297:Male; D012720:Severity of Illness Index
chemical_list: D002859:Chromium Isotopes