title: Increased mean corpuscular haemoglobin concentration: artefact or pathological condition?
abstract: BACKGROUND
  In daily practice in haematology laboratories, spurious increased MCHC induces an analytical alarm and needs prompt corrective action to ensure delivery of the right results to the clinicians. The aim of this study was to establish a 'decision tree' using the new parameters red blood cells (RBC-O) and haemoglobin (HGB-O) from the Sysmex XN-10 RET obtained by flow cytometry to deliver appropriate results.
  
  
  METHODS
  From 128 unknown patients with MCHC > 365 g/L, all erythrocyte parameters including reticulocyte parameters were measured and analysed in parallel with blood smears, chemistry index and osmolarity. Differences between optical parameters (RBC-O, HGB-O) and usual parameters (RBC, HGB) obtained by impedance and photometry were reported also.
  
  
  RESULTS
  Four groups were defined from observations: -RBC agglutination (n = 22); -optical interference (n = 17); -RBC disease (n = 18); and -others (n = 71). The use of RBC-O and HGB-O permitted efficient correction of the abnormalities when RBC agglutination and/or optical interference were present in 36 of 39 patients. Reticulocyte parameters permitted to elaborate an RBC score that allowed a highly sensitive detection of RBC disease patients (17/18).
  
  
  CONCLUSIONS
  Based on new parameters, we propose a 'decision tree' that delivers time savings and supports biological interpretation in case of elevated MCHC.
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.
authors: Y
authors: Y
authors: Berda-Haddad
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.
authors: C
authors: C
authors: Faure
authors: Clinical Research Unit, Avicenne Hospital, Bobigny, France.
authors: M
authors: M
authors: Boubaya
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.
authors: M
authors: M
authors: Arpin
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.|VRCM, UMR-S1076, Aix -Marseille Université, INSERM, UFR de Pharmacie, Marseille, France.
authors: S
authors: S
authors: Cointe
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.
authors: D
authors: D
authors: Frankel
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.|VRCM, UMR-S1076, Aix -Marseille Université, INSERM, UFR de Pharmacie, Marseille, France.
authors: R
authors: R
authors: Lacroix
authors: Department of Haematology and Vascular Biology, CHU Conception, AP-HM, Marseille, France.|VRCM, UMR-S1076, Aix -Marseille Université, INSERM, UFR de Pharmacie, Marseille, France.
authors: F
authors: F
authors: Dignat-George
mesh_terms: D000328:Adult; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008297:Male; D012156:Reticulocytes / Q000378:metabolism*
chemical_list: D006454:Hemoglobins
keywords: Laboratory practice; XN-10 RET; analytical interference; decision tree; elevated MCHC; laboratory automation