The Anti-Cardiolipin IgA (aCL IgA) Test is a specialized blood assay used to detect Immunoglobulin A (IgA) antibodies that target cardiolipin, a key phospholipid found in cell membranes. While the IgG and IgM classes of Anti-Cardiolipin antibodies are the standard primary markers for Antiphospholipid Syndrome (APS), the IgA test is used in specific clinical situations.