Mean Corpuscular Hemoglobin Concentration in Hemoglobin CC, SC, and AC

Point mutation in the hemoglobin beta chain generates many deviants from the normal format hemoglobin A, which contains 2 alpha chains and 2 beta chains. Among the numerous deviants, Hemoglobin C (HbC) and Hemoglobin S (HbS, sickle cell hemoglobin) are 2 of the most common variants with clinical significance. Mean corpuscular hemoglobin concentration (MCHC) is of a measurement of the concentration of hemoglobin in a given volume of packed red blood cells. It is one of the red cell indices measured daily in every blood specimen, which provides clues to the clinicians about the quality of the red cells and the associated diseases. Previous studies have suggested that patients with HbCC and HbSC, and up to 45% patients with HbAC present with high MCHC. However, in our practice we found that the MCHC values in these patients showed a broad spectrum. To clarify this discrepancy, 388 peripheral blood specimens with HbCC (homozygous C), HbSC (compound heterozygous S and C), or HbAC (heterozygous C) were pulled out from hospital’s medical records. We found about 50% of the HbCC patients and 20% of HbSC patients had elevated MCHC, and in HbAC patients, elevation of MCHC was rare. Therefore, our study sheds new light on the interpretation of MCHC in daily practice.

[1]  R. Fairhurst,et al.  Altered Membrane Structure and Surface Potential in Homozygous Hemoglobin C Erythrocytes , 2009, PloS one.

[2]  P. Vekilov,et al.  Phase separation and crystallization of hemoglobin C in transgenic mouse and human erythrocytes. , 2008, Biophysical journal.

[3]  J. Lilleyman,et al.  Discriminant function using red cell indices to distinguish between HbC and HbE traits. , 2008, Clinical and laboratory haematology.

[4]  G Bourner,et al.  Performance evaluation of the latest fully automated hematology analyzers in a large, commercial laboratory setting: a 4-way, side-by-side study. , 2005, Laboratory hematology : official publication of the International Society for Laboratory Hematology.

[5]  R. Nagel,et al.  Crystallization mechanisms of hemoglobin C in the R state. , 2004, Biophysical journal.

[6]  R. Nagel,et al.  Expression of HbC and HbS, but not HbA, results in activation of K-Cl cotransport activity in transgenic mouse red cells. , 2004, Blood.

[7]  R. Nagel,et al.  The paradox of hemoglobin SC disease. , 2003, Blood reviews.

[8]  T. Lazar,et al.  Hematology: Clinical Principles and Applications , 2002 .

[9]  R. Nagel,et al.  Intermolecular interactions, nucleation, and thermodynamics of crystallization of hemoglobin C. , 2002, Biophysical journal.

[10]  J. Friedman,et al.  A potential determinant of enhanced crystallization of HbC: spectroscopic and functional evidence of an alteration in the central cavity of oxyHbC , 1997, British journal of haematology.

[11]  J. Lilleyman,et al.  Mean cell haemoglobin concentration in subjects with haemoglobin C, D, E and S traits. , 1996, Clinical and laboratory haematology.

[12]  S. Ballas,et al.  Erythrocytes in Hb SC disease are microcytic and hyperchromic , 1988, American journal of hematology.

[13]  O. Castro,et al.  Red cell distribution width in sickle cell disease. , 1986, Annals of clinical and laboratory science.

[14]  R. Nagel,et al.  Volume‐dependent and NEM‐stimulated K+Cl−1 transport is elevated in oxygenated SS, SC and CC human red cells , 1986, FEBS letters.

[15]  M. Steinberg,et al.  The effects of alpha‐thalassaemia in HbSC disease , 1983, British journal of haematology.

[16]  R. Nagel,et al.  SC erythrocytes have an abnormally high intracellular hemoglobin concentration. Pathophysiological consequences. , 1982, The Journal of clinical investigation.

[17]  S. Charache,et al.  HEREDITARY PERSISTENCE OF FETAL HEMOGLOBIN 1 , 1969, Annals of the New York Academy of Sciences.

[18]  S. Charache,et al.  Pathogenesis of hemolytic anemia in homozygous hemoglobin C disease. , 1967, The Journal of clinical investigation.

[19]  Thomas J. Kipps,et al.  Williams manual of hematology , 2011 .

[20]  D. Rifkind,et al.  The pediatric abacus : review of clinical formulas and how to use them , 2002 .

[21]  M. J. Pollack,et al.  Differential pathways in oxy and deoxy HbC aggregation/crystallization , 2001, Proteins.

[22]  E. Rappaport,et al.  The xerocytosis of Hb SC disease. , 1987, Blood.