The immunologic identification of abnormal hemoglobins

Area of Science:

• Immunology and Biochemistry
• Molecular Genetics
• Clinical Diagnostics

Background:

• Human hemoglobin variants possess multiple antigenic determinants.
• Amino acid substitutions in hemoglobin variants can lead to antigenic deficiency.
• Radioimmunoassay (RIA) systems can detect these antigenically deficient hemoglobin variants.

Purpose of the Study:

• To develop more selective antisera for differentiating human hemoglobin variants.
• To create specific antibodies for Hb A, Hb S, and Hb C beta-chains.
• To assess the utility of these antisera for clinical diagnostics, including prenatal screening.

Main Methods:

• Generation of guinea pig antisera against human hemoglobin.
• Absorption of multivalent antisera with specific hemoglobin variants to enhance selectivity.
• Radioimmunoassay (RIA) to test the discriminating ability of the developed antisera.
• Complementation tests to determine the approximate location of substitutions in novel variants.

Main Results:

• Development of three specific antisera targeting Hb A, Hb S, and Hb C beta-chains.
• Demonstrated ability to differentiate between individuals with single or combined Hb S and Hb C variants.
• Antisera maintained discriminating ability even in the presence of high concentrations of Hb F (fetal hemoglobin).
• Detection of additional Hb A variants and localization of substitutions using complementation tests.

Conclusions:

• Selective antisera can be generated by absorbing multivalent antibodies.
• These specific antisera are effective tools for differentiating common and novel hemoglobin variants.
• The antisera are suitable for early prenatal diagnosis of sickle cell disorders due to their specificity and robustness against Hb F.