title: Platelet factor 4/heparin-particle gel immunoassay (PaGIA) is a weak method for heparin-induced thrombocytopenia (HIT) evaluation of post cardio-pulmonary bypass surgery patients.
abstract: Diagnosis of heparin induced thrombocytopenia (HIT) is not always easy, especially when a confirmatory functional test is not available. In most cases the diagnosis relies on the combination of pretest probability and an immunologic test. Among patients post cardiopulmonary bypass (CPB) surgery, anti-platelet factor 4/heparin antibodies tend to be high but with low clinical implication. The current retrospective study examined the behavior of patients with positive PF4/heparin-PaGIA results, divided into two groups according to whether or not they have undergone CPB surgery. The main focus of the study was on the reliability of the PF4/heparin-PaGIA test in these two settings. The files of 104 single center patients, who had a positive PF4/heparin-PaGIA test, were reviewed. 62% were post CPB and 38% were not. An association between the intensity of positivity of PF4/heparin-PaGIA test and both the 4Ts pretest probability method (p = 0.003) and the incidence of thrombosis (p = 0.02) was found only in the patients who have not undergone CPB surgery, but not in the CPB patients. This study suggests that PF4/heparin-PaGIA is not a reliable method in patients post CPB surgery who are investigated for a possible diagnosis of HIT.
authors.affiliation: Department of Hematology, Shaare Zedek Medical Center, P.O.B. 3235, 91031, Jerusalem, Israel, ganzelc@szmc.org.il.
authors.forename: Chezi
authors.initials: C
authors.lastname: Ganzel
authors.forename: Jacob
authors.initials: J
authors.lastname: Rowe
authors.forename: David
authors.initials: D
authors.lastname: Raveh
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry; D002315:Cardiopulmonary Bypass; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects / Q000737:chemistry; D006801:Humans; D007118:Immunoassay; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010978:Platelet Factor 4 / Q000097:blood*; D011183:Postoperative Complications / Q000097:blood / Q000139:chemically induced / Q000453:epidemiology; D012189:Retrospective Studies; D013921:Thrombocytopenia / Q000097:blood / Q000139:chemically induced / Q000453:epidemiology
chemical_list: D000925:Anticoagulants; D010978:Platelet Factor 4; D006493:Heparin