Anemia hemolítica autoimune: uma análise literária das alterações laboratoriais e morfológicas como ferramentas diagnósticas

Abstract

Autoimmune hemolytic anemia (AIHA) is characterized by the presence of autoantibodies or complement fractions that bind to the surface of erythrocytes, causing their destruction and is an uncommon clinical condition. Therefore, this literature review addressed general aspects and classification of AHAIs and, with more emphasis, the main tests useful for diagnosis and how laboratory changes and erythrocyte morphology can help in the diagnostic elucidation of this disease. From September 2023 to October 2024, scientific articles were selected from databases such as PubMed and CAPES Periodicals, using specific keywords, such as autoimmune hemolytic anemia, laboratory changes, pathophysiology, among others, with the aim of compiling information on the topic, making it possible to expose a current panorama that is little explored and has great potential in helping to diagnose this disease. AIHAs can be hot, cold or mixed, depending on the class of antibody involved, and, as in other hemolytic anemias, they present a low level of hemoglobin and high serum levels of lactate dehydrogenase, unconjugated bilirubin and low levels of haptoglobin, In addition, the reticulocyte count frequently indicates reticulocytosis. The main examination of AIHA diagnosis is the direct antiglobulin test, which will reveal antibodies or complement in the patient's erythrocytes. Blood distension analysis can highlight changes common to all types of AIHA, such as polychromasia, and in more severe cases, erythroblasts and schistocytes can be observed. Specifically, microspherocytes can be seen in hot AIHA while red blood cell agglutination is present in cold AIHA and become useful tools in diagnostic elucidation, especially in situations where the gold standard is not capable of concluding the patient's real clinical condition. Among the laboratory and morphological findings observed throughout the work, it is concluded that these can assist in the diagnosis of this pathology, and it is up to the biomedical professional to be attentive to the results, with their presence in the laboratory environment being extremely important in these circumstances.