Page 2229 - Hematology_ Basic Principles and Practice ( PDFDrive )

1976 Part XII Hemostasis and Thrombosis

First day of antibody detection

Beginning of HIT-related platelet count fall
Summary
of 12 HIT
patient
profiles Platelet count fall ≥50%

3.0 Thrombotic event

Start of heparin
2.5 Non-HIT (mean day 1.21) ** ** **
EIA-GAM OD (mean +/– SEM) 1.5 GAM (n = 12) (n = 36) * ** **
HIT (mean day 1.38)
2.0

Non-HIT
HIT

1.0
HIT vs. Non-HIT

0.5 **p < .005, *p < .05 *
EIA OD cut-off

0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
A Days after surgery

1.6

1.4
HIT Non-HIT
(n = 12) (n = 36)
1.2 IgG ** ** ** * *
EIA-Ig OD (mean +/– SEM) 0.8 IgM **
IgA
1.0
HIT vs. Non-HIT
**p < .005, *p < .05

0.6

0.4 **
*
EIA OD
0.2 cut-off

0
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
B Days after surgery
Fig. 133.2 CHARACTERISTIC TIMELINE OF HEPARIN-INDUCED THROMBOCYTOPENIA. Antiplatelet 4 (PF4)/heparin antibodies (by enzyme
immunoassay [EIA]) per postoperative day in 12 patients with heparin-induced thrombocytopenia (HIT) and 36 seropositive non-HIT control patients. (A)
Mean (± standard error of the mean [SEM]) optical density (OD) of anti-PF4/heparin antibodies detected using commercial immunoassay (EIA-GAM) that
detects antibodies of all three immunoglobulin classes (IgG, IgA, IgM). HIT patients are indicated by blue squares, and seropositive non-HIT controls by green
squares. On each day beginning on postoperative day 6, there is a significant difference in the mean of the OD levels between the patients with HIT and the
seropositive non-HIT controls (p < .05 by nonpaired t-test). At the top of the figure, summary data for 12 HIT patient profiles are shown for four key events
(first day of antibody detection, beginning of HIT-related platelet count fall, platelet count fall ≥50%, and thrombotic event), summarized as median (small
purple squares within rectangles), interquartile range (rectangles), and range (ends of thin black lines). (B) Mean (±SEM) OD values of anti-PF4/heparin antibodies
detected using an in-house immunoassay (EIA-Ig) that detects antibodies of the individual immunoglobulin classes, IgG (red circles), IgA (green triangles), and
IgM (blue inverted triangles) for HIT (solid symbols) and non-HIT (open symbols). On each postoperative day beginning on day 5, there is a significant difference
in the mean of the OD units for the IgG immunoassay between the patients with HIT and the seropositive non-HIT controls (**p < .005 for days 6–10; *p <
.05 for days 5, 11, and 12). (From Warkentin TE, Sheppard JI, Moore JC, et al: Studies of the immune response in heparin-induced thrombocytopenia. Blood 113:4693, 2009.)