Familial acquired thrombotic thrombocytopenic purpura: ADAMTS13 inhibitory autoantibodies in identical twins.
Thrombotic thrombocytopenic purpura (TTP) either occurs in a congenital form caused by ADAMTS13 gene mutations or it is acquired and most often due to ADAMTS13 inhibitory autoantibodies. In congenital TTP siblings are often affected, while acquired TTP occurs sporadically and familial clustering has not been described so far. We report identical twin sisters suffering from acquired TTP due to immunoglobulin G (IgG) autoantibodies inactivating ADAMTS13, suggesting an important role of hitherto unidentified genetic determinants of ADAMTS13 inhibitor formation. These cases also demonstrate that familial clustering is not sufficient for unambiguously diagnosing hereditary ADAMTS13 deficiency and congenital TTP.
Central Hematology Laboratory, Inselspital, University Hospital, CH-3010 Bern, Switzerland.
Jan-Dirk
JD
Studt
Johanna A
JA
Kremer Hovinga
Radovan
R
Radonic
Vladimir
V
Gasparovic
Dragutin
D
Ivanovic
Marijan
M
Merkler
Urs
U
Wirthmueller
Clemens
C
Dahinden
Miha
M
Furlan
Bernhard
B
Lämmle
D051722:ADAM Proteins; D000071120:ADAMTS13 Protein; D000328:Adult; D001323:Autoantibodies / Q000097:blood; D005260:Female; D006650:Histocompatibility Testing; D006801:Humans; D008666:Metalloendopeptidases / Q000172:deficiency / Q000235:genetics* / Q000276:immunology*; D011697:Purpura, Thrombotic Thrombocytopenic / Q000235:genetics* / Q000276:immunology*; D014430:Twins, Monozygotic / Q000235:genetics
D001323:Autoantibodies; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000071120:ADAMTS13 Protein; C099604:ADAMTS13 protein, human