[Heparin induced thrombocytopenia: case report with acute thrombotic complications and literature review].
OBJECTIVE
Review of the frequency, clinical and biological features and treatment of type II heparin-induced thrombocyopenia.


METHODS
Case report and literature review.


RESULTS
A 65 years old woman received as antithrombotic prophylaxis low molecular weight heparin (LMWH) after prosthetic knee replacement. Day 8, asymptomatic deep vein thrombosis was discovered after systematic echodoppler examination. Curative anticoagulation was started with LMWH. A fall in the platelet count (17 G/L) was noted day 12. Danaparoid was immediately introduced and heparin discontinued. However, day 16 a massive pulmonary embolism occurred which required transfer to an intensive care unit. Danaparoid was changed for lepirudin the same day. It took longer than three weeks for platelet count to return to normal value after heparin discontinuation. The suspicion of heparin-induced thrombocyopenia was confirmed by specific tests.


CONCLUSIONS
HIT type II are rare but life-threatening and thrombosis events are the most frequent complications. The diagnosis is a high probability proved by both clinical and biological patterns. The treatment consists in alternative thrombin inhibitors such as danaparoid and lepirudin. The platelet count usually requires less than ten days to recover normal values after heparin withdrawal. Cases in which the delay to a normal platelet count exceeds 3 weeks have been reported specially after LMWH therapy.


CONCLUSIONS
Type II HIT are rare but life-threatening events can occur. The platelet count check-up during heparin therapy must be systematic.
Plassat
R
R
services de médecine physique et réadaptation CHU, C3RF, rue des Capucins BP 40329, 49103 cedex, Angers, France.
Cognet
F
F
Ternisien
C
C
Ménoret
N
N
Dubus-Bausière
V
V
Brunel
P
P
Bontoux
L
L
Bernat
C
C
Richard
I
I
D000368:Aged; D000925:Anticoagulants / Q000009:adverse effects* / Q000627:therapeutic use; D019645:Arthroplasty, Replacement, Knee; D002809:Chondroitin Sulfates / Q000627:therapeutic use; D003871:Dermatan Sulfate / Q000627:therapeutic use; D004338:Drug Combinations; D005260:Female; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects* / Q000627:therapeutic use; D006497:Heparan Sulfate / Q000627:therapeutic use; D006801:Humans; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000150:complications*; D013927:Thrombosis / Q000139:chemically induced*
D000925:Anticoagulants; D002809:Chondroitin Sulfates; D003871:Dermatan Sulfate; D004338:Drug Combinations; D006495:Heparin, Low-Molecular-Weight; D006497:Heparan Sulfate; C035838:danaparoid