D-dimer Plasma D-dimer is a product of clot breakdown, released upon degradation of polymerized, crosslinked fibrin. Elevated plasma D-dimer levels indicate that coagulation has been activated, fibrin clot has formed, & clot degradation by plasmin has occurred. D-dimer has been shown to increase with age, which can cause a ↓ specificity (i.e. more false positive tests) in older patients. Specificity can range from 49-67% in 50 yrs of age, but in older patients (i.e. 80 yrs of age) the specificity is 0-18% How do you perform age adjusted d-dimer testing? - Age (yrs) x 10 u g/ L for > 50 yrs of age - Example: Patient age 88 = age adjusted d-dimer of 880 u g/ L Satyendra Dhar, MD @DharSaty #Ddimer #dimer #pathophysiology #hematology #differential #diagnosis #age #adjusted
