TTP - Laboratory Evaluation for Thrombotic Thrombocytopenic Purpura



Activity of von Willebrand factor-cleaving protease activity - A low value for this enzyme activity is the diagnostic hallmark for the disease, but the assay may not be available for rapid diagnosis ofTTP. If the value is low, tests to detect an inhibitor to the protease can be performed	

PT, PTT, and fibrinogen levels - Usually normal	

Fibrin degradation products or D-dimer - Normal or slightly elevated	

Hemoglobin/hematocrit - Mild-to-moderate decrease in most cases; hemorrhage and hemolysis can result in severe anemia in some patients	

Haptoglobin - Low as a reflection of intravascular hemolysis	

Platelet count - Decreased, often in the range of	

Peripheral blood smear - Shows schistocytes, nucleated RBCs, and decreased platelet number	

Direct and indirect antiglobulin tests - Negative, ruling out an immune hemolytic anemia	

Indirect bilirubin - Mild-to-moderate elevation	

Serum lactate dehydrogenase (LDH) - Elevated, correlating with the severity of hemolysis and possibly tissue damage from ischemia	

WBC count and differential - Shows a mild leukocytosis with a left shift	

Urinalysis - Characterized by mild-to-moderate proteinuria and hematuria (without casts)	

BUN and creatinine - May or may not be elevated, depending on the presence of renal impairment	



#TTP #ThromboticThrombocytopenicPurpura #Diagnosis #Workup #Hematology