Mixed autoimmune hemolytic anemia (MAIHA) is a type of

autoimmune hemolytic anemia Autoimmune hemolytic anemia (AIHA) occurs when a person's immune system produces antibodies directed against their own red blood cells (RBCs). These antibodies attach to red cells, causing them to break down ( lyse), and reducing the number of ox ...

which combines the features of cold sensitive antibody-induced diseases and

warm autoimmune hemolytic anemia Warm antibody autoimmune hemolytic anemia (WAIHA) is the most common form of autoimmune haemolytic anemia. About half of the cases are of unknown cause, with the other half attributable to a predisposing condition or medications being taken. Contr ...

. The work-up for diagnosis is complex and the condition can be over-diagnosed. People diagnosed with warm autoimmune hemolytic anemia (WAIHA) caused by

immunoglobulin G Immunoglobulin G (IgG) is a type of antibody. Representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. Each IgG ...

(IgG) may also have a high number of

immunoglobulin M Immunoglobulin M (IgM) is the largest of several isotypes of antibodies (also known as immunoglobulin) that are produced by vertebrates. IgM is the first antibody to appear in the response to initial exposure to an antigen; causing it to also ...

(

IgM Immunoglobulin M (IgM) is the largest of several isotypes of antibodies (also known as immunoglobulin) that are produced by vertebrates. IgM is the first antibody to appear in the response to initial exposure to an antigen; causing it to also ...

) antibodies. These antibodies are active at room temperature, but are believed to be harmless since they are not the main antibodies responsible for WAIHA. However, studies revealed the existence of a few cases of WAIHA that may also carry cold agglutinin antibodies that are active at the environment where the temperatures is generally equal to or warmer than 30 °C (86 °F). Such coexistence suggests a diagnosis of the mixed (warm- and cold-antibody) autoimmune hemolytic anemia abbreviated as MAIHA. Mixed warm and cold AIHA runs a chronic course with severe intermittent exacerbations, such as serious anemia, and is treated by

blood transfusion Blood transfusion is the process of transferring blood products into a person's Circulatory system, circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used ...

. Successful therapeutic options for the treatment of hemolysis associated with mixed AIHA are limited but increasing. In the past, there were two obvious sources of error regarding the diagnosis of AIHA. First, patients with w-AIHA can produce low-

titer Titer (American English) or titre (British English) is a way of expressing concentration. Titer testing employs serial dilution to obtain approximate quantitative information from an analytical procedure that inherently only evaluates as positi ...

, low-thermal amplitude CA of no clinical significance. Second, up to 20% of patients with CAD have IgG on the RBC surface in addition to C3d.

References

{{Diseases_of_RBCs Autoimmune hemolytic anemia Hematology Antibodies Blood disorders

See also

References