Summary of Previously Published Studies on the Impact of FcγRIIa-R-H131 Polymorphism in HIT Patients
| Study . | Patient Inclusion Criteria . | n . | FcγRIIa Genotype* . | Control Group . | n . | FcγRIIa Genotype* . | P . | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| R/R131 . | R/H131 . | H/H131 . | R/R131 . | R/H131 . | H/H131 . | ||||||
| Burgess et al21 | Clinical criteria of HIT† | 19 | 0 | 15 | 4 | Normal healthy individuals | 22 | 7 | 13 | 2 | <.05 |
| Brandt et al22 | Thrombocytopenia or thrombosis‡ | 96 | 22 (23) | 41 (43) | 33 (34) | Hospital controls | 100 | 32 (32) | 49 (49) | 19 (19) | <.05 |
| Arepally et al23 | Clinical criteria of HIT2-153 | 36 | 9 (25) | 19 (53) | 8 (22) | Outpatient controls | 102 | 26 (25) | 56 (55) | 20 (20) | .95 |
| Denomme et al24 | Clinical criteria of HIT2-155 | 84 | (23)¶ | (41)¶ | (36)¶ | Inpatient controls | 95 | (27)¶ | (52)¶ | (21)¶ | <.001 |
| Study . | Patient Inclusion Criteria . | n . | FcγRIIa Genotype* . | Control Group . | n . | FcγRIIa Genotype* . | P . | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| R/R131 . | R/H131 . | H/H131 . | R/R131 . | R/H131 . | H/H131 . | ||||||
| Burgess et al21 | Clinical criteria of HIT† | 19 | 0 | 15 | 4 | Normal healthy individuals | 22 | 7 | 13 | 2 | <.05 |
| Brandt et al22 | Thrombocytopenia or thrombosis‡ | 96 | 22 (23) | 41 (43) | 33 (34) | Hospital controls | 100 | 32 (32) | 49 (49) | 19 (19) | <.05 |
| Arepally et al23 | Clinical criteria of HIT2-153 | 36 | 9 (25) | 19 (53) | 8 (22) | Outpatient controls | 102 | 26 (25) | 56 (55) | 20 (20) | .95 |
| Denomme et al24 | Clinical criteria of HIT2-155 | 84 | (23)¶ | (41)¶ | (36)¶ | Inpatient controls | 95 | (27)¶ | (52)¶ | (21)¶ | <.001 |
*Values are the number of patients with the percentage in parentheses.
Thrombocytopenia occurring during heparin administration (resolving after heparin withdrawal), heparin-dependent antibodies detected in patient sera/plasma (platelet aggregometry or 14C-serotonin release assay), and exclusion of other recognized causes of thrombocytopenia.
Occurrence of thrombocytopenia or thrombosis during heparin administration and a positive platelet aggregation assay.
Published clinical criteria32a and diagnosis confirmed by detection of heparin-dependent antibodies (14C-serotonin release assay).
Thrombocytopenia occurring 5 or more days after start of heparin (resolving after discontinuation of heparin) and presence of HIT IgG (14C-serotonin release assay).
¶Only percentages are given in the publication.