Heparin-induced thrombocytopenia in patients with Philadelphia-negative myeloproliferative disorders and unusual splanchnic or cerebral vein thrombosis.
BACKGROUND
Philadelphia-negative myeloproliferative disorders (Ph-MPD) are common causes of unusual splanchnic or cerebral vein thrombosis, which is treated with unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). Heparin-induced thrombocytopenia (HIT) is a dangerous potential complication of this therapy, but it has rarely been reported in Ph-MPD.


METHODS
We retrospectively reviewed clinical records of 29 patients with Ph-MPD who have been treated with UFH or LMWH for unusual splanchnic or cerebral vein thrombosis (3 cerebral sinus, 6 portal and 20 hepatic vein). The goal of the study was to determine the occurrence of new thrombotic events during heparin therapy secondary to HIT (HITT).


RESULTS
During heparin therapy, 5 out of the 29 patients (17%) developed a new thrombotic episode (pulmonary embolism) with a high clinical probability of HIT based on the 4 T's score even though not all the patients developed 'true' thrombocytopenia. A diagnosis of HIT was established in 2 patients (6.8%) through the presence of heparin-related antibodies.


CONCLUSIONS
Ph-MPD patients on heparin warrant careful monitoring and HIT has to be suspected whenever platelet counts drop or a new thrombosis is detectable.
Department of Medical and Surgical Sciences, University of Padua Medical School, Padua, Italy.
Maria L
ML
Randi
Fabiana
F
Tezza
Margherita
M
Scapin
Elena
E
Duner
Pamela
P
Scarparo
Raffaella
R
Scandellari
Fabrizio
F
Fabris
D000328:Adult; D000925:Anticoagulants / Q000009:adverse effects* / Q000276:immunology / Q000627:therapeutic use; D006502:Budd-Chiari Syndrome / Q000150:complications / Q000188:drug therapy; D016903:Drug Monitoring; D005260:Female; D006493:Heparin / Q000009:adverse effects* / Q000276:immunology / Q000627:therapeutic use; D006495:Heparin, Low-Molecular-Weight / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use; D006801:Humans; D020767:Intracranial Thrombosis / Q000150:complications / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D009196:Myeloproliferative Disorders / Q000150:complications*; D010976:Platelet Count; D011087:Polycythemia Vera / Q000150:complications; D011655:Pulmonary Embolism / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D012189:Retrospective Studies; D013920:Thrombocythemia, Essential / Q000150:complications; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000209:etiology / Q000276:immunology; D013927:Thrombosis / Q000150:complications / Q000188:drug therapy*; D013997:Time Factors; D055815:Young Adult
D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D006493:Heparin