PMID- 12190890
OWN - NLM
STAT- MEDLINE
DCOM- 20020916
LR  - 20190906
IS  - 0954-6820 (Print)
IS  - 0954-6820 (Linking)
VI  - 252
IP  - 2
DP  - 2002 Aug
TI  - Risk factors for thrombosis in patients with immune mediated heparin-induced 
      thrombocytopenia.
PG  - 149-54
AB  - BACKGROUND: As reported by major clinical series in the literature, about 2% of 
      patients receiving unfractionated heparin (UFH) develop immune-mediated (type II) 
      heparin-induced thrombocytopenia (HIT) that may be complicated in 30-75% of cases 
      by a paradoxical thrombotic syndrome (HITTS), either arterial or venous. HITTS 
      carries relevant rates of mortality and morbidity, amongst which cerebral and/or 
      myocardial infarction and limb amputations. It is unclear as yet why some 
      patients suffer from isolated thrombocytopenia (HIT), whilst others have HITTS. 
      The aim of the present study was to look for clinical and laboratory features 
      related to the occurrence of HITTS. PATIENTS AND METHODS: We retrospectively 
      analysed the clinical records of 56 patients with proven HIT, as diagnosed on 
      clinical grounds and by in vitro demonstration of immunoglobulin (IgG)/IgM 
      against the PF4/heparin complex. Thirty-four patients (61%) had HITTS (19 venous 
      thrombosis, seven arterial thrombosis, five arterial and venous thrombosis, two 
      skin necrosis, one diffuse intravascular coagulation), whereas 22 had 
      uncomplicated HIT. Amongst HITTS patients, two had limb amputation, five had 
      recurrent thrombosis and seven died. Amongst HIT patients three died from causes 
      unrelated to HIT. RESULTS: No significant difference in sex, age, previous 
      exposure to heparin, UFH route of administration or dose, duration of therapy, 
      time of onset of thrombocytopenia and platelet count recovery, nor 
      antiheparin/PF4 antibodies subtype (IgG or IgM) was detected when comparing HIT 
      and HITTS. In contrast, in the HITTS group a higher prevalence of orthopaedic 
      surgery (15 of 34 vs. 2/22; P=0.01), a significantly lower platelet count nadir 
      (43 +/- 32 vs. 75 +/- 63 x 109/L; P=0.01) and a significantly higher titre of 
      antiheparin/PF4 antibodies, expressed as optical density of enzyme-linked 
      immunosorbent assay (ELISA); (1989 +/- 1024 vs. 1277 +/- 858; P=0.009), were 
      observed in comparison with the HIT group. Amongst HITTS patients, the prevalence 
      of venous thrombosis was significantly higher in orthopaedic patients and in 
      those being treated for venous thromboembolism (18/24 vs. 1/9 patients, chi2 8.4, 
      P=0.004), whilst arterial thrombosis (ART) occurred more often in heparin 
      treatment for arterial disease (3/4 vs. 4/29 patients, chi2 4.6, P=0.03). 
      CONCLUSIONS: Orthopaedic surgery, the severity of thrombocytopenia and high 
      antiheparin/PF4 antibodies titre are adverse prognostic or concurrent factors in 
      the development of HITTS.
FAU - Fabris, F
AU  - Fabris F
AD  - Clinica Medica II, Department of Medical and Surgical Sciences, University of 
      Padua Medical School, Padova, Italy. fabrizio.fabris@unipd.it
FAU - Luzzatto, G
AU  - Luzzatto G
FAU - Soini, B
AU  - Soini B
FAU - Ramon, R
AU  - Ramon R
FAU - Scandellari, R
AU  - Scandellari R
FAU - Randi, M L
AU  - Randi ML
FAU - Girolami, A
AU  - Girolami A
LA  - eng
PT  - Journal Article
PL  - England
TA  - J Intern Med
JT  - Journal of internal medicine
JID - 8904841
RN  - 0 (Antibodies)
RN  - 0 (Anticoagulants)
RN  - 9005-49-6 (Heparin)
SB  - IM
MH  - Adult
MH  - Aged
MH  - Aged, 80 and over
MH  - Antibodies/blood
MH  - Anticoagulants/adverse effects/*immunology
MH  - Female
MH  - Heparin/adverse effects/*immunology
MH  - Humans
MH  - Male
MH  - Medical Records
MH  - Middle Aged
MH  - Orthopedic Procedures/adverse effects
MH  - Retrospective Studies
MH  - Risk Factors
MH  - Severity of Illness Index
MH  - Thrombocytopenia/chemically induced/*complications/immunology
MH  - Thrombosis/*etiology
EDAT- 2002/08/23 10:00
MHDA- 2002/09/17 10:01
CRDT- 2002/08/23 10:00
PHST- 2002/08/23 10:00 [pubmed]
PHST- 2002/09/17 10:01 [medline]
PHST- 2002/08/23 10:00 [entrez]
AID - 1021 [pii]
AID - 10.1046/j.1365-2796.2002.01021.x [doi]
PST - ppublish
SO  - J Intern Med. 2002 Aug;252(2):149-54. doi: 10.1046/j.1365-2796.2002.01021.x.