Microangiopathic hemolytic anemia laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Mydah Sajid, MD [2]

Overview

Laboratory findings consistent with the diagnosis of microangiopathic hemolytic anemia include blood complete picture indicating hemolytic anemia, low platelet count and renal derangements. Specific tests like bacterial antigen detection, enzyme and antibody assays are done to diagnose underlying cause like hemolytic uremic syndrome and thrombotic thrombocytopenic purpura.

Laboratory findings consistent with the diagnosis of microangiopathic hemolytic anemia include^[1]:

Normochromic normocytic anemia
Thrombocytopenia usually significant with platelet count less than 20,000/μL.
High reticulocyte count
Raised red ce distribution width
Raised mean platelet volume
Decreased haptoglobin levels
Elevated unconjugated bilirubin level
Elevated lactate dehydrogenase
Red cell polychromasia, anisocytosis, and normochromic appearance with a lack of central pallor.
As red blood cells travel through these damaged vessels, they are shredded. The result is red cell fragmentation and intravascular hemolysis. Under the microscope, damaged red cells have the appearance of schistocytes. It includes helmet cells, irregular projections, and crescent-shape^[2]^[3].
Automated analysers (the machines that perform routine full blood counts in most hospitals) are generally programmed to flag blood films that display red blood cell fragments or schistocytes.
Raised urine urobilinogen level
Elevated plasma creatinine level
Proteinuria
Hematuria