STRUCTURAL HAEMOGLOBINOPATHY CARRIERS CAN BE IDENTIFIED BY LABORATORY PARAMETERS PROVIDED BY ADVIA 2120 ANALYSER
(Abstract release date: 05/19/16)
EHA Library. Velasco-Rodríguez D. 06/09/16; 133021; E1472
Mr. Diego Velasco-Rodríguez
Contributions
Contributions
Abstract
Abstract: E1472
Type: Eposter Presentation
Background
Hemoglobinopathies have spread owing to human migrations, and the number of people needing diagnosis and management of these conditions is increasing. More than 1500 variant Hb have been described to date. In more than 95% of variant Hb, the structural alteration is a point mutation that produces a single amino acid substitution in a globin chain. 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 that discriminate between structural hemoglobinopathy carriers and healthy subjects
Methods
Samples of 500 variant Hb carriers (355 HbAS, 104 HbAC, 19 HbAD, 7 HbAE, 7 HbAO-Arab, 4 alpha-chain variants and 4 Hb Lepore) and 251 normal controls were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). 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. A multivariable binary logistic regression model was created to predict the probability of a subject carrying any structural hemoglobinopathy.
Results
Variant Hb carriers presented significantly higher RBC count (4.96×1012/L vs 4.84×1012/L, p=0.031), lower MCV (85.39 fL vs 92.81 fL, p<0.001), lower MCH (28.97 pg vs 30.18 pg, p<0.001), higher MCHC (34.29 g/dL vs 32.71 g/dL, p<0.001), higher RDW (14.10% vs 12.94%, p<0.001), lower %MACRO (0.67% vs 1.63%, p<0.001), higher %MICRO (2.31% vs 0.42%, p<0.001), higher %HYPER (1.99% vs 0.45%, p<0.001), lower %HYPO (1.51% vs 2.47%, p<0.001) and higher M/H (9.31% vs 0.67%, p<0.001). A clinical prediction rule was developed by assigning one point to each of the most efficient variables: mean corpuscular volume (MCV) <88.4 fL, RBC distribution width >13.4%, percentage of microcytic RBCs (%MICRO) >0.7% and the ratio of microcytic RBCs to hypochromic RBCs >0.8. A score of 0, 1, 2, 3 or 4, resulted in a probability of 9.6%, 36.3%, 66.7%, 85.2% or 98.3%, respectively.
Conclusion
Although molecular analysis (gold standard) or another laboratory technique such as electrophoresis and/or HPLC is mandatory for the diagnosis of structural hemoglobinopathies, a CBC is a quick, cheap and handy test that provides useful information for a presumptive diagnosis of these entities. RBCs of variant Hb carriers are smaller, denser and show a higher degree of anisocytosis in comparison to RBcs of normal controls. Structural hemoglobinopathy investigation should be performed if a score of 3 or 4 is seen in subjects belonging to ethnic groups with a high prevalence of variant Hb. Our model is not structured as a complex mathematical formula, and in our opinion, this facilitates its clinical use. Although differences in haematological parameters have been reported by many authors, none evaluated the value of the CBC as a screening tool to identify variant Hb carriers.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Screening
Type: Eposter Presentation
Background
Hemoglobinopathies have spread owing to human migrations, and the number of people needing diagnosis and management of these conditions is increasing. More than 1500 variant Hb have been described to date. In more than 95% of variant Hb, the structural alteration is a point mutation that produces a single amino acid substitution in a globin chain. 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 that discriminate between structural hemoglobinopathy carriers and healthy subjects
Methods
Samples of 500 variant Hb carriers (355 HbAS, 104 HbAC, 19 HbAD, 7 HbAE, 7 HbAO-Arab, 4 alpha-chain variants and 4 Hb Lepore) and 251 normal controls were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). 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. A multivariable binary logistic regression model was created to predict the probability of a subject carrying any structural hemoglobinopathy.
Results
Variant Hb carriers presented significantly higher RBC count (4.96×1012/L vs 4.84×1012/L, p=0.031), lower MCV (85.39 fL vs 92.81 fL, p<0.001), lower MCH (28.97 pg vs 30.18 pg, p<0.001), higher MCHC (34.29 g/dL vs 32.71 g/dL, p<0.001), higher RDW (14.10% vs 12.94%, p<0.001), lower %MACRO (0.67% vs 1.63%, p<0.001), higher %MICRO (2.31% vs 0.42%, p<0.001), higher %HYPER (1.99% vs 0.45%, p<0.001), lower %HYPO (1.51% vs 2.47%, p<0.001) and higher M/H (9.31% vs 0.67%, p<0.001). A clinical prediction rule was developed by assigning one point to each of the most efficient variables: mean corpuscular volume (MCV) <88.4 fL, RBC distribution width >13.4%, percentage of microcytic RBCs (%MICRO) >0.7% and the ratio of microcytic RBCs to hypochromic RBCs >0.8. A score of 0, 1, 2, 3 or 4, resulted in a probability of 9.6%, 36.3%, 66.7%, 85.2% or 98.3%, respectively.
Conclusion
Although molecular analysis (gold standard) or another laboratory technique such as electrophoresis and/or HPLC is mandatory for the diagnosis of structural hemoglobinopathies, a CBC is a quick, cheap and handy test that provides useful information for a presumptive diagnosis of these entities. RBCs of variant Hb carriers are smaller, denser and show a higher degree of anisocytosis in comparison to RBcs of normal controls. Structural hemoglobinopathy investigation should be performed if a score of 3 or 4 is seen in subjects belonging to ethnic groups with a high prevalence of variant Hb. Our model is not structured as a complex mathematical formula, and in our opinion, this facilitates its clinical use. Although differences in haematological parameters have been reported by many authors, none evaluated the value of the CBC as a screening tool to identify variant Hb carriers.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Screening
Abstract: E1472
Type: Eposter Presentation
Background
Hemoglobinopathies have spread owing to human migrations, and the number of people needing diagnosis and management of these conditions is increasing. More than 1500 variant Hb have been described to date. In more than 95% of variant Hb, the structural alteration is a point mutation that produces a single amino acid substitution in a globin chain. 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 that discriminate between structural hemoglobinopathy carriers and healthy subjects
Methods
Samples of 500 variant Hb carriers (355 HbAS, 104 HbAC, 19 HbAD, 7 HbAE, 7 HbAO-Arab, 4 alpha-chain variants and 4 Hb Lepore) and 251 normal controls were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). 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. A multivariable binary logistic regression model was created to predict the probability of a subject carrying any structural hemoglobinopathy.
Results
Variant Hb carriers presented significantly higher RBC count (4.96×1012/L vs 4.84×1012/L, p=0.031), lower MCV (85.39 fL vs 92.81 fL, p<0.001), lower MCH (28.97 pg vs 30.18 pg, p<0.001), higher MCHC (34.29 g/dL vs 32.71 g/dL, p<0.001), higher RDW (14.10% vs 12.94%, p<0.001), lower %MACRO (0.67% vs 1.63%, p<0.001), higher %MICRO (2.31% vs 0.42%, p<0.001), higher %HYPER (1.99% vs 0.45%, p<0.001), lower %HYPO (1.51% vs 2.47%, p<0.001) and higher M/H (9.31% vs 0.67%, p<0.001). A clinical prediction rule was developed by assigning one point to each of the most efficient variables: mean corpuscular volume (MCV) <88.4 fL, RBC distribution width >13.4%, percentage of microcytic RBCs (%MICRO) >0.7% and the ratio of microcytic RBCs to hypochromic RBCs >0.8. A score of 0, 1, 2, 3 or 4, resulted in a probability of 9.6%, 36.3%, 66.7%, 85.2% or 98.3%, respectively.
Conclusion
Although molecular analysis (gold standard) or another laboratory technique such as electrophoresis and/or HPLC is mandatory for the diagnosis of structural hemoglobinopathies, a CBC is a quick, cheap and handy test that provides useful information for a presumptive diagnosis of these entities. RBCs of variant Hb carriers are smaller, denser and show a higher degree of anisocytosis in comparison to RBcs of normal controls. Structural hemoglobinopathy investigation should be performed if a score of 3 or 4 is seen in subjects belonging to ethnic groups with a high prevalence of variant Hb. Our model is not structured as a complex mathematical formula, and in our opinion, this facilitates its clinical use. Although differences in haematological parameters have been reported by many authors, none evaluated the value of the CBC as a screening tool to identify variant Hb carriers.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Screening
Type: Eposter Presentation
Background
Hemoglobinopathies have spread owing to human migrations, and the number of people needing diagnosis and management of these conditions is increasing. More than 1500 variant Hb have been described to date. In more than 95% of variant Hb, the structural alteration is a point mutation that produces a single amino acid substitution in a globin chain. 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 that discriminate between structural hemoglobinopathy carriers and healthy subjects
Methods
Samples of 500 variant Hb carriers (355 HbAS, 104 HbAC, 19 HbAD, 7 HbAE, 7 HbAO-Arab, 4 alpha-chain variants and 4 Hb Lepore) and 251 normal controls were run on an Advia 2120 analyser (Siemens Medical Solutions Diagnostics, Tarrytown, New York, USA). 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. A multivariable binary logistic regression model was created to predict the probability of a subject carrying any structural hemoglobinopathy.
Results
Variant Hb carriers presented significantly higher RBC count (4.96×1012/L vs 4.84×1012/L, p=0.031), lower MCV (85.39 fL vs 92.81 fL, p<0.001), lower MCH (28.97 pg vs 30.18 pg, p<0.001), higher MCHC (34.29 g/dL vs 32.71 g/dL, p<0.001), higher RDW (14.10% vs 12.94%, p<0.001), lower %MACRO (0.67% vs 1.63%, p<0.001), higher %MICRO (2.31% vs 0.42%, p<0.001), higher %HYPER (1.99% vs 0.45%, p<0.001), lower %HYPO (1.51% vs 2.47%, p<0.001) and higher M/H (9.31% vs 0.67%, p<0.001). A clinical prediction rule was developed by assigning one point to each of the most efficient variables: mean corpuscular volume (MCV) <88.4 fL, RBC distribution width >13.4%, percentage of microcytic RBCs (%MICRO) >0.7% and the ratio of microcytic RBCs to hypochromic RBCs >0.8. A score of 0, 1, 2, 3 or 4, resulted in a probability of 9.6%, 36.3%, 66.7%, 85.2% or 98.3%, respectively.
Conclusion
Although molecular analysis (gold standard) or another laboratory technique such as electrophoresis and/or HPLC is mandatory for the diagnosis of structural hemoglobinopathies, a CBC is a quick, cheap and handy test that provides useful information for a presumptive diagnosis of these entities. RBCs of variant Hb carriers are smaller, denser and show a higher degree of anisocytosis in comparison to RBcs of normal controls. Structural hemoglobinopathy investigation should be performed if a score of 3 or 4 is seen in subjects belonging to ethnic groups with a high prevalence of variant Hb. Our model is not structured as a complex mathematical formula, and in our opinion, this facilitates its clinical use. Although differences in haematological parameters have been reported by many authors, none evaluated the value of the CBC as a screening tool to identify variant Hb carriers.
Session topic: E-poster
Keyword(s): Globin gene, Hemoglobin variants, Hemoglobinopathy, Screening
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