Table 1. Binding of heparin-induced... | American Society of Hematology

Table 1.

Binding of heparin-induced thrombocytopenia (HIT) sera to PF4 variants

Patients with HIT	WT	P37N	T38Q	A39V	L41V	N47D	NAP2
Sensitive (n = 5)	3.10 ± 0.56	0.60 ± 0.31	1.56 ± 1.08^†	2.51 ± 0.99	1.67 ± 1.22	1.52 ± 1.10^*	0.34 ± 0.31
A₄₀₅ <1.0
Intermediate (n = 9)	3.41 ± 0.40	1.98 ± 0.34	2.42 ± 1.06	3.12 ± 0.70	1.94 ± 1.10	3.12 ± 1.18	0.61 ± 0.42
A₄₀₅ ≥1.0 to <2.5
Insensitive (n = 9)	3.66 ± 0.10	2.99 ± 0.40	3.45 ± 0.29^†	3.27 ± 1.12	1.91 ± 1.44	2.88 ± 1.10^*	0.45 ± 0.38
A₄₀₅ ≥2.5
Total (n = 23)	3.44 ± 0.41	2.06 ± 0.98	2.64 ± 1.10	3.04 ± 0.97	1.87 ± 1.22	2.64 ± 1.27	0.48 ± 0.38

Patients with HIT	WT	P37N	T38Q	A39V	L41V	N47D	NAP2
Sensitive (n = 5)	3.10 ± 0.56	0.60 ± 0.31	1.56 ± 1.08^†	2.51 ± 0.99	1.67 ± 1.22	1.52 ± 1.10^*	0.34 ± 0.31
A₄₀₅ <1.0
Intermediate (n = 9)	3.41 ± 0.40	1.98 ± 0.34	2.42 ± 1.06	3.12 ± 0.70	1.94 ± 1.10	3.12 ± 1.18	0.61 ± 0.42
A₄₀₅ ≥1.0 to <2.5
Insensitive (n = 9)	3.66 ± 0.10	2.99 ± 0.40	3.45 ± 0.29^†	3.27 ± 1.12	1.91 ± 1.44	2.88 ± 1.10^*	0.45 ± 0.38
A₄₀₅ ≥2.5
Total (n = 23)	3.44 ± 0.41	2.06 ± 0.98	2.64 ± 1.10	3.04 ± 0.97	1.87 ± 1.22	2.64 ± 1.27	0.48 ± 0.38

Binding studies of 23 HIT sera to PF4 variants complexed to heparin, each with an A₄₀₅ to wild-type PF4/heparin of >2.5. Subgroups of patients were classified by reactivity to mutations involving the third domain of PF4. Sera losing reactivity to third-domain mutations with A₄₀₅ <1.0 were defined as sensitive, those retaining activity with A₄₀₅ >2.5 as insensitive, and those with A₄₀₅ ≥1.0 to ≤2.5 as intermediate in reactivity. The mean ± 1 SD is shown.

P < .05;

†

P < .01.

View Large

This Feature Is Available To Subscribers Only