Platelet Antibody Workup for Platelet Transfusion Refractory Patients
| Label Mnemonic: | Platelet Antibody Workup |
| Epic code: | LAB4388 |
| Downtime form: | A-1a Doctor-Provider Orders - Pathology Blood Center |
DeGowin Blood Center - Blood Bank
C271 GH
356-2561
C271 GH
356-2561
Specimen(s):
Blood
Collection Medium:
 | or |  |
| Pink top tube 6 mL (K2-EDTA) | Lavender top tube 3 mL (EDTA) |
Minimum:
Adult Minimum: 5 mL
Pediatric Minimum: 2 mL
Pediatric Minimum: 2 mL
Rejection Criteria:
Specimen must be labeled with patient's first and last name and medical record number. Specimens will be rejected if information is not on the label when received.
Delivery Instructions:
Deliver to laboratory immediately after collection.Testing Schedule:
0700-1400 Monday through Friday. All tests must be approved by the Clinical Pathology Resident (Pager 3404). The sample should be delivered by 10:00 a.m. for same-day testing. Result is accompanied by professional consultation and if indicated a platelet crossmatch with platelets in inventory will be performed to identify platelets for transfusion.
Reference Range:
No reactivity.
Comments:
This test is for patients known to be refractory to platelet transfusions. All tests must be approved by the Clinical Pathology Resident (Pager 3404) and we highly recommend you also order a "Consult DeGowin Blood Center Physician" (Lab7611) so DeGowin Faculty can assist with the assessment and management of these patients.
This testing is used by the Blood Bank to determine whether platelet refractoriness may be immune-mediated. Either a screening test using the Immucor Capture-P assay to detect IgG antibodies against HLA or platelet antigens or a platelet crossmatch are performed. In some cases, performing HLA typing and testing for HLA Class I specific antibodies may assist in the identification of HLA matched platelets for refractory patients. These tests require separate orders and are done by an outside reference laboratory. It generally takes take 3-5 days to receive HLA matched platelets. This test is not recommended for the diagnosis of idiopathic thrombocytopenic purpura (ITP) due to low sensitivity and specificity (Blood 1997 89:1112-4).
This testing is used by the Blood Bank to determine whether platelet refractoriness may be immune-mediated. Either a screening test using the Immucor Capture-P assay to detect IgG antibodies against HLA or platelet antigens or a platelet crossmatch are performed. In some cases, performing HLA typing and testing for HLA Class I specific antibodies may assist in the identification of HLA matched platelets for refractory patients. These tests require separate orders and are done by an outside reference laboratory. It generally takes take 3-5 days to receive HLA matched platelets. This test is not recommended for the diagnosis of idiopathic thrombocytopenic purpura (ITP) due to low sensitivity and specificity (Blood 1997 89:1112-4).
Test
Limitations:
This test does not detect non-immune causes of platelet refractoriness such as splenomegaly, DIC and bleeding. Our experience indicates this testing can identify platelets that are more likely to provide adequate increments (CCI>5) but in many cases crossmatched or HLA matched platelets fail to provide good CCIs.
Methodology:
Capture-P solid phase assay from Immucor. Platelet antigens (screen) or platelets in inventory (crossmatch) are captured on a well and incubated with patient serum. Antibody binding is detected using IgG coated indicator RBCs.
CPT Code:
86022
See Additional Information:
Specimens Requiring Immediate Delivery
Specimens Requiring Immediate Delivery