Diagnostic relevance of ADAMTS13 activity: evaluation of 28 patients with thrombotic thrombocytopenic purpura - hemolytic uremic syndrome clinical diagnosis.
BACKGROUND
The significance of ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin motif-13) activity for diagnosis and therapy of thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) is still a controversial issue.


OBJECTIVE
The aim of this report was to analyze the value of ADAMTS13 measurements in the diagnosis of TTP and HUS.


METHODS
At presentation, we analyzed patients with idiopathic TTP (n = 18), secondary TTP (n = 4), diarrhea positive HUS (n = 3) and diarrhea negative HUS (n = 3) treated in Belgrade, Serbia from 2004 to 2010. ADAMTS13 activity from acute phase samples was measured using the residual collagen binding activity assay at the Haemophilia and Thrombosis Centre, Milan, Italy.


RESULTS
There was a significant correlation between reduced ADAMTS13 activity and idiopathic TTP diagnosis (p = 0.000) as well as between lower ADAMTS13 activities and higher reticulocytes (p = 0.017) and lactate dehydrogenase levels (p = 0.027). Significant correlation was also found between higher protease activity and diagnosis of HUS (p = 0.000). There was a statistically significant correlation between higher ADAMTS13 activities and higher platelets count (p = 0.002), blood urea nitrogen (p = 0.000), and creatinine level (p = 0.000).


CONCLUSIONS
Severe ADAMTS13 deficiency points at the diagnosis of idiopathic TTP and it is present in the secondary TTP but not in HUS.
Clinic of Digestive Surgery, Clinical Center of Serbia, Dr Koste Todorovića 6, 11000 Belgrade, Serbia. vucelicd@beotel.net
Dragica
D
Vucelić
Danijela
D
Miković
Zoran
Z
Rajić
Nebojsa
N
Savić
Zivko
Z
Budisin
Nebojsa M
NM
Antonijević
Slobodan
S
Obradović
Dragana
D
Jevtić
Roberta
R
Palla
Carla
C
Valsecchio
Flora
F
Peyvandi
D051722:ADAM Proteins / Q000378:metabolism*; D000071120:ADAMTS13 Protein; D006463:Hemolytic-Uremic Syndrome / Q000201:enzymology / Q000453:epidemiology / Q000378:metabolism; D006801:Humans; D011697:Purpura, Thrombotic Thrombocytopenic / Q000201:enzymology / Q000453:epidemiology / Q000378:metabolism; D055771:Serbia / Q000453:epidemiology
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human