​Pathology - Autoimmune Hemolytic Anemias

​Pathology - Autoimmune Hemolytic Anemias
Warm antibody autoimmune hemolytic anemia (WAIHA) is characterized by the presence of IgG antibodies that target the red blood cell (RBC) membrane. The development of these IgG antibodies can occur without a known cause (idiopathic) or as a result of an underlying condition such as stem cell disorders or lymphomas.
Cold agglutinin illness is a condition where large IgM antibodies target and bind to the I antigen on red blood cells, causing them to be engulfed by phagocytes. The development of these IgM antibodies is often of unknown cause (idiopathic) or can be associated with Waldenstrom macroglobulinemia. Infectious mononucleosis. or infection caused by Mycoplasma pneumoniae
In addition to WAIHA and cold agglutinin illness, autoimmune hemolytic anemia (AIHA) can also be caused by some pharmacological agents such as sulfa medications, quinidine, and rifampin.

Study of the nature and causes of diseases. 
WAIHA: The examination of the blood sample shows the presence of microspherocytes, which are erythrocytes that are spherical in shape and lack a central pale area. Additionally, there is an increased number of reticulocytes.
CAD: The examination of a sample of peripheral blood reveals the presence of microspherocytes, which are erythrocytes that are spherical in shape and lack a core area of pallor. Additionally, there is an increased number of reticulocytes.

Symptoms and signs 
WAIHA: Severe destruction of red blood cells, resulting in jaundice and enlargement of the spleen. Laboratory results include a positive direct Coombs test, reduced hematocrit, raised lactate dehydrogenase (LDH), and elevated indirect bilirubin.
CAD: Cold-induced hemolytic anemia resulting in jaundice. Laboratory results include a positive cold agglutinin test, reduced hemoglobin, raised lactate dehydrogenase (LDH), and elevated indirect bilirubin.

Therapy 
WAIHA: Administer appropriate treatment for the root cause of the condition, such as steroids, intravenous immune globulin, and/or splenectomy in severe instances.
CAD: Severe instances should be protected from cold environments and measures should be taken to avoid immunosuppression.
The direct Coombs test examines the existence of antibodies on the surface of red blood cells (RBCs). The indirect Coombs test evaluates the existence of unbound antibodies in the patient's serum.