Investigations
| Platelet immunology | |
| Genotyping: | |
| Maternal platelet genotype: | HPA-1b1b; HPA-2a2a; HPA-3a3b; HPA-4a4a; HPA-5a5b |
| Paternal platelet genotype: | HPA-1a1b; HPA-2a2a; HPA-3a3a; HPA-4a4a; HPA-5a5a |
| Twin 1 platelet genotype: | HPA-1b1b; HPA-2a2a; HPA-3a3b; HPA-4a4a; HPA-5a5a |
| Twin 2 platelet genotype: | HPA-1a1b; HPA-2a2a; HPA-3a3a; HPA-4a4a; HPA-5a5b |
| Indirect platelet immunofluorescence (PIFT): | |
| IgG platelet antibodies detected in mother's serum | |
| Positive reactions with 6/6 HPA/HLA typed panel cells | |
| Monoclonal antibody specific immobilisation of platelet antigen assay (MAIPA): | |
| Anti-HPA 1a antibody detected, titre >1/16 | |
| Solid phase ELISA (PAK): | |
| Anti-HPA 1a antibody detected, HLA antibodies also detected | |
| Crossmatch of maternal serum versus paternal platelets: | |
| Positive reactions between mother's serum and father's platelets | |
| Strongly positive for anti-GPIIb/IIIa | |
| HLA typing and antibody screen | |
| Class I typing: | |
| Mother: | A1; B8 |
| Father: | A2; B27 B60 |
| Twin 1: | A1 A2; B8 B60 |
| Twin 2: | A1 A2; B8 B27 |
| Lymphocyte cytotoxicity test (LCT): | |
| Maternal serum: | Multispecific HLA antibodies detected, titre >1/16 |
| Infectious screen: | |
| Blood cultures: | Negative |
| Urine cultures: | Negative |
| TORCH: | Negative |