Increased mean corpuscular haemoglobin concentration: artefact or pathological condition?

Abstract

Summary Introduction 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). Conclusion Based on new parameters, we propose a ‘decision tree’ that delivers time savings and supports biological interpretation in case of elevated MCHC.

Short preheating at 41°C leads to a red blood cells count comparable to that in RET channel of Sysmex analysers in samples showing cold agglutination

“…According to a previous report,20 similar differences are observed between MCV and R-MFV (P<0.005; figure 1B), between I-MCHC and O-MCHC (calculated as [HGB/RBC-O × R-MFV]) (P<0.05; figure 1C) and, finally, between basic DLT- RBC and one at 37°C/2 hours (P<0.05; figure 1D). …”

“…Haematocrit (HTC) is measured as cumulative height of electrical pulse produced by each cell passing through two electrodes, and MCV is calculated as [HTC/RBC] 20. MCH and MCHC are calculated according to Wintrobe formulas 21.…”

Eliminating or Minimizing the Effects of Cold Agglutinins on the Accuracy of Complete Blood Count Results

“…Although other methods have been proposed, such as the replacement of plasma with a warm isotonic solution [3], the Finland method is one of the most widely employed to date. More recently, in some hematological analyzers, including Sysmex XE-2100 and XN-1000, the counting in the reticulocyte (RET) channel is sufficient to provide accurate red blood cell (RBC) counts, as well as Wintrobe indices, without thermal pre-treatment of the sample [45678]. Similar observations have not been described for Unicel DxH 800 and ADIVA 2120i, in which the environmental conditions in the RET channel do not lead to the spontaneous resolution of cold agglutination.…”

Use of Sysmex XN‐10 red blood cell parameters for screening of hereditary red blood cell diseases and iron deficiency anaemia

“…Samples presenting with an increased MCHC value (>365 g/L) were reflexed in the RET (reticulocyte) channel and classified as per the CBC‐O application 4 developed by Sysmex that is embedded in the Extended Information Processing Unit ( Extended‐ IPU). The RBC score was calculated as per Berda et al recommendation and embedded reticulocytes absolute count and the percentage of fragments reported by the XN analyser when reticulocytes are measured.…”

“…Median, minimum and maximum values for analysed RBC parameters in the 5 groups RDW-SD < 38.5 fL) were observed. One patient from "OTHERS" was included for the same reason (RDW-SD 36 4. fl).…”