ERYTHROCYTES OF INDIVIDUALS WITH HEMOGLOBIN C TRAIT ARE DENSER AND SMALLER THAN ERYTHROCYTES OF OF INDIVIDUALS WITH HEMOGLOBIN S TRAIT
(Abstract release date: 05/19/16)
EHA Library. Velasco-Rodríguez D. 06/09/16; 135021; PB2121
Mr. Diego Velasco-Rodríguez
Contributions
Contributions
Abstract
Abstract: PB2121
Type: Publication Only
Background
Since HbS and HbC are by far the two most prevalent structural hemoglobinopathies in our geographical area, it seems reasonable to develop efficient and rapid tools to discriminate between them in daily practice. Carriers are asymptomatic, and clinicians need to accurately identify them and provide adequate genetic counselling to them in order to prevent the occurrence of homozygous or compound heterozygous offspring.
Aims
The aim of our study was to identify red blood cell (RBC) laboratory parameters of the complete blood count (CBC) that discriminate between HbAS and HbAC individuals.
Methods
The CBC of 355 HbAS and 104 HbAC subjects were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). All of these Hb variants were detected by HPLC in the HA-8160 analyzer (Menarini Diagnostics, Florence, Italy) and further characterised according to their alkaline and acid electrophoretic pattern using cellulose acetate electrophoresis. Classic hematological parameters and RBC populations of the complete blood count (CBC) were assessed in all subjects. Independent sample t-test was used to compare laboratory parameters between HbAS and HbAC, and receiver operating characteristic (ROC) curves were plotted.
Results
The following parameters were significantly higher in HbAC than in HbAS: RBCs (5.09×1012/L vs 4.91×1012/L, p=0.004), Hb (13.97 g/dL vs 13.47 g/dL, p=0.017), MCHC (35.35 g/dL vs 33.29 g/dL, p<0.001), RDW (15.16% vs 14.51%, p=0.002), HDW (2.68% vs 2.48%, p=0.001), %MICRO (7.35% vs 4.58%, p=0.006), %HYPER (3.04% vs 0.82%, p<0.001) and M/H (22.37 vs 4.59, p<0.001). The following parameters were significantly higher in HbAS than in HbAC: MCV (82.92 fL vs 79.15 fL, p<0.001), %MACRO (0.45% vs 0.27%, p=0.033) and %HYPO (4.51% vs 1.27%, p<0.001). When only HbAS and HbAC without iron deficiency and α-TT were evaluated, differences remained significant only in MCV, MCHC, %MICRO, %HYPER and M/H (Table 1). %HYPER (AUC=0.842), M/H (AUC=0.839) and MCHC (AUC=0.833) were the most efficient parameters to discriminate between HbAS and HbAC. A cut-off point of 1.15% for %HYPER provided a sensitivity of 79.9% and a specificity of 74.4%. A cut-off point of 34.55 g/dL for MCHC provided a sensitivity of 80.6% and a specificity of 72.1%. A cut-off point of 7.3 for M/H provided a sensitivity of 81.6% and a specificity of 76.7%.
Conclusion
RBCs of HbAC subjects are denser than HbAS erythrocytes, possibly because the K+:Cl− cotransporter may be more active in HbAC subjects, since lysine (HbC) is more positively charged than valine (HbS), and thus its binding to band 3 may be even further increased. If a patient with a variant Hb not yet identified shows hyperchromia (% HYPER >1.15% and/or MCHC >34.55 g/dL and/or M/H >7.3), the diagnosis is more likely to be HbAC.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Sickle cell
Type: Publication Only
Background
Since HbS and HbC are by far the two most prevalent structural hemoglobinopathies in our geographical area, it seems reasonable to develop efficient and rapid tools to discriminate between them in daily practice. Carriers are asymptomatic, and clinicians need to accurately identify them and provide adequate genetic counselling to them in order to prevent the occurrence of homozygous or compound heterozygous offspring.
Aims
The aim of our study was to identify red blood cell (RBC) laboratory parameters of the complete blood count (CBC) that discriminate between HbAS and HbAC individuals.
Methods
The CBC of 355 HbAS and 104 HbAC subjects were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). All of these Hb variants were detected by HPLC in the HA-8160 analyzer (Menarini Diagnostics, Florence, Italy) and further characterised according to their alkaline and acid electrophoretic pattern using cellulose acetate electrophoresis. Classic hematological parameters and RBC populations of the complete blood count (CBC) were assessed in all subjects. Independent sample t-test was used to compare laboratory parameters between HbAS and HbAC, and receiver operating characteristic (ROC) curves were plotted.
Results
The following parameters were significantly higher in HbAC than in HbAS: RBCs (5.09×1012/L vs 4.91×1012/L, p=0.004), Hb (13.97 g/dL vs 13.47 g/dL, p=0.017), MCHC (35.35 g/dL vs 33.29 g/dL, p<0.001), RDW (15.16% vs 14.51%, p=0.002), HDW (2.68% vs 2.48%, p=0.001), %MICRO (7.35% vs 4.58%, p=0.006), %HYPER (3.04% vs 0.82%, p<0.001) and M/H (22.37 vs 4.59, p<0.001). The following parameters were significantly higher in HbAS than in HbAC: MCV (82.92 fL vs 79.15 fL, p<0.001), %MACRO (0.45% vs 0.27%, p=0.033) and %HYPO (4.51% vs 1.27%, p<0.001). When only HbAS and HbAC without iron deficiency and α-TT were evaluated, differences remained significant only in MCV, MCHC, %MICRO, %HYPER and M/H (Table 1). %HYPER (AUC=0.842), M/H (AUC=0.839) and MCHC (AUC=0.833) were the most efficient parameters to discriminate between HbAS and HbAC. A cut-off point of 1.15% for %HYPER provided a sensitivity of 79.9% and a specificity of 74.4%. A cut-off point of 34.55 g/dL for MCHC provided a sensitivity of 80.6% and a specificity of 72.1%. A cut-off point of 7.3 for M/H provided a sensitivity of 81.6% and a specificity of 76.7%.
Conclusion
RBCs of HbAC subjects are denser than HbAS erythrocytes, possibly because the K+:Cl− cotransporter may be more active in HbAC subjects, since lysine (HbC) is more positively charged than valine (HbS), and thus its binding to band 3 may be even further increased. If a patient with a variant Hb not yet identified shows hyperchromia (% HYPER >1.15% and/or MCHC >34.55 g/dL and/or M/H >7.3), the diagnosis is more likely to be HbAC.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Sickle cell
Abstract: PB2121
Type: Publication Only
Background
Since HbS and HbC are by far the two most prevalent structural hemoglobinopathies in our geographical area, it seems reasonable to develop efficient and rapid tools to discriminate between them in daily practice. Carriers are asymptomatic, and clinicians need to accurately identify them and provide adequate genetic counselling to them in order to prevent the occurrence of homozygous or compound heterozygous offspring.
Aims
The aim of our study was to identify red blood cell (RBC) laboratory parameters of the complete blood count (CBC) that discriminate between HbAS and HbAC individuals.
Methods
The CBC of 355 HbAS and 104 HbAC subjects were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). All of these Hb variants were detected by HPLC in the HA-8160 analyzer (Menarini Diagnostics, Florence, Italy) and further characterised according to their alkaline and acid electrophoretic pattern using cellulose acetate electrophoresis. Classic hematological parameters and RBC populations of the complete blood count (CBC) were assessed in all subjects. Independent sample t-test was used to compare laboratory parameters between HbAS and HbAC, and receiver operating characteristic (ROC) curves were plotted.
Results
The following parameters were significantly higher in HbAC than in HbAS: RBCs (5.09×1012/L vs 4.91×1012/L, p=0.004), Hb (13.97 g/dL vs 13.47 g/dL, p=0.017), MCHC (35.35 g/dL vs 33.29 g/dL, p<0.001), RDW (15.16% vs 14.51%, p=0.002), HDW (2.68% vs 2.48%, p=0.001), %MICRO (7.35% vs 4.58%, p=0.006), %HYPER (3.04% vs 0.82%, p<0.001) and M/H (22.37 vs 4.59, p<0.001). The following parameters were significantly higher in HbAS than in HbAC: MCV (82.92 fL vs 79.15 fL, p<0.001), %MACRO (0.45% vs 0.27%, p=0.033) and %HYPO (4.51% vs 1.27%, p<0.001). When only HbAS and HbAC without iron deficiency and α-TT were evaluated, differences remained significant only in MCV, MCHC, %MICRO, %HYPER and M/H (Table 1). %HYPER (AUC=0.842), M/H (AUC=0.839) and MCHC (AUC=0.833) were the most efficient parameters to discriminate between HbAS and HbAC. A cut-off point of 1.15% for %HYPER provided a sensitivity of 79.9% and a specificity of 74.4%. A cut-off point of 34.55 g/dL for MCHC provided a sensitivity of 80.6% and a specificity of 72.1%. A cut-off point of 7.3 for M/H provided a sensitivity of 81.6% and a specificity of 76.7%.
Conclusion
RBCs of HbAC subjects are denser than HbAS erythrocytes, possibly because the K+:Cl− cotransporter may be more active in HbAC subjects, since lysine (HbC) is more positively charged than valine (HbS), and thus its binding to band 3 may be even further increased. If a patient with a variant Hb not yet identified shows hyperchromia (% HYPER >1.15% and/or MCHC >34.55 g/dL and/or M/H >7.3), the diagnosis is more likely to be HbAC.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Sickle cell
Type: Publication Only
Background
Since HbS and HbC are by far the two most prevalent structural hemoglobinopathies in our geographical area, it seems reasonable to develop efficient and rapid tools to discriminate between them in daily practice. Carriers are asymptomatic, and clinicians need to accurately identify them and provide adequate genetic counselling to them in order to prevent the occurrence of homozygous or compound heterozygous offspring.
Aims
The aim of our study was to identify red blood cell (RBC) laboratory parameters of the complete blood count (CBC) that discriminate between HbAS and HbAC individuals.
Methods
The CBC of 355 HbAS and 104 HbAC subjects were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). All of these Hb variants were detected by HPLC in the HA-8160 analyzer (Menarini Diagnostics, Florence, Italy) and further characterised according to their alkaline and acid electrophoretic pattern using cellulose acetate electrophoresis. Classic hematological parameters and RBC populations of the complete blood count (CBC) were assessed in all subjects. Independent sample t-test was used to compare laboratory parameters between HbAS and HbAC, and receiver operating characteristic (ROC) curves were plotted.
Results
The following parameters were significantly higher in HbAC than in HbAS: RBCs (5.09×1012/L vs 4.91×1012/L, p=0.004), Hb (13.97 g/dL vs 13.47 g/dL, p=0.017), MCHC (35.35 g/dL vs 33.29 g/dL, p<0.001), RDW (15.16% vs 14.51%, p=0.002), HDW (2.68% vs 2.48%, p=0.001), %MICRO (7.35% vs 4.58%, p=0.006), %HYPER (3.04% vs 0.82%, p<0.001) and M/H (22.37 vs 4.59, p<0.001). The following parameters were significantly higher in HbAS than in HbAC: MCV (82.92 fL vs 79.15 fL, p<0.001), %MACRO (0.45% vs 0.27%, p=0.033) and %HYPO (4.51% vs 1.27%, p<0.001). When only HbAS and HbAC without iron deficiency and α-TT were evaluated, differences remained significant only in MCV, MCHC, %MICRO, %HYPER and M/H (Table 1). %HYPER (AUC=0.842), M/H (AUC=0.839) and MCHC (AUC=0.833) were the most efficient parameters to discriminate between HbAS and HbAC. A cut-off point of 1.15% for %HYPER provided a sensitivity of 79.9% and a specificity of 74.4%. A cut-off point of 34.55 g/dL for MCHC provided a sensitivity of 80.6% and a specificity of 72.1%. A cut-off point of 7.3 for M/H provided a sensitivity of 81.6% and a specificity of 76.7%.
Conclusion
RBCs of HbAC subjects are denser than HbAS erythrocytes, possibly because the K+:Cl− cotransporter may be more active in HbAC subjects, since lysine (HbC) is more positively charged than valine (HbS), and thus its binding to band 3 may be even further increased. If a patient with a variant Hb not yet identified shows hyperchromia (% HYPER >1.15% and/or MCHC >34.55 g/dL and/or M/H >7.3), the diagnosis is more likely to be HbAC.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Sickle cell
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