The role of serological and molecular testing in the diagnostics and transfusion treatment of autoimmune haemolytic anaemia

Abstract

Autoimmune haemolytic anaemia (AIHA) is a rare autoimmune disease characterised by haemolysis associated with the presence of immunoglobulins and/or components of the complement system on red blood cells (RBCs). It is classified into warm or cold antibody-mediated AIHA according to the temperature at which autoantibodies bind optimally to RBCs. Clinicians should be familiar with the procedural tests used for a complete laboratory investigation of AIHA. Good collaboration between clinicians and laboratory specialists with correct sample handling and an exact diagnostic work-up is extremely important for the correct classification and proper therapeutic management of AIHA. Specialised serological test procedures are very complex. Problems with serological testing may be excluded with the molecular testing, which has now become a gold standard to predict a patient's phenotype in order to secure the right antigen-matched blood for AIHA patients. More recently, genotyping has been used instead of serological typing and complex adsorption tests. This paper offers a description of various tests for differentiating between types of AIHA. A diagnostic algorithm and the problems of laboratory investigation are also presented, and an application of molecular methods for the blood group typing in AIHA is elaborated.

Figure 1

Diagnostic algorithm for the investigation of autoimmune haemolytic anaemia AA: autoantibodies; AIHA: autoimmune haemolitic anaemia; BH: biphasic haemolysins; CA: cold autoantibodies; CAD: cold agglutinin disease; DAggT: direct agglutinin test; DAT: direct antiglobulin test; DL: Donath-Landsteimer test; IAT: indirect antiglobulin test; PCH: paroxysmal cold haemoglobinuria.