Home
HelpTest Code LAGGN Granulocyte Antibody Screen, Serum
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube: Red top (serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Additional Information: Only a specimen collected before a transfusion reaction is acceptable.
Secondary ID
621630Useful For
Work-up of individuals with autoimmune neutropenia
Work-up of individuals having febrile nonhemolytic transfusion reactions
Work-up for alloimmune neonatal neutropenia
This test is not useful for the diagnosis of neutropenia due to marrow suppression by drugs or tumors.
Method Name
Flow Cytometry/Agglutination
Reporting Name
Granulocyte Ab Screen, SSpecimen Type
Serum RedSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum Red | Refrigerated (preferred) | 30 days |
| Frozen | 365 days | |
| Ambient | 7 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Clinical Information
Granulocyte antibodies are induced by pregnancy, prior transfusion, or transplants. These antibodies can cause neutropenia in various autoimmune disorders. Febrile nonhemolytic transfusion reactions and alloimmune neonatal neutropenia may also be caused by granulocyte associated antibodies, including anti-human leukocyte antigen antibodies.
Reference Values
Not applicable
Interpretation
A positive result can be due to anti-granulocyte antibodies and anti-human leukocyte antigen antibodies.
This test cannot distinguish between allo- or autoantibodies, nor can it determine the specificity of the detected antibody. Results should be correlated to clinical history.
Cautions
Testing for patients who receive human monoclonal antibodies like daratumumab may cause false-positive results due to interfering substances. Hemolytic samples have the potential for causing false-positivity and will, therefore, be rejected.
Clinical Reference
1. Flesch BK, Reil A. Molecular genetics of the human neutrophil antigens. Transfus Med Hemother. 2018;45(5):300-309. doi:10.1159/000491031
2. Gottschall JL, Triulzi DJ, Curtis B, et al. The frequency and specificity of human neutrophil antigen antibodies in a blood donor population. Transfusion. 2011;51(4):820-827. doi:10.1111/j.1537-2995.2010.02913.x
3. Browne T, Dearman RJ, Poles A. Human neutrophil antigens: Nature, clinical significance and detection. Int J Immunogenet. 2021;48(2):145-156. doi:10.1111/iji.12514
4. Baig NA, Dukek BA, Falbo DK, et al. Daratumumab interference in flow cytometric anti-granulocyte antibody testing can be overcome using non-human blocking antibodies. Vox Sang. 2021;116(1):116-122. doi:10.1111/vox.12989
Method Description
The screening for granulocyte antibodies is conducted using two methods: the granulocyte immunofluorescence test (GIFT) and the granulocyte agglutination test (GAT). The combined interpretation of GIFT/GAT results is considered the gold standard for granulocyte antibody screening. Both methods are performed in parallel by mixing the patient's serum with freshly collected granulocytes from healthy donors.
The GIFT method detects antibodies in the patient's serum that bind to donor granulocytes through indirect immunofluorescence staining using anti-human IgG-fluorescein isothiocyanate and anti-human IgM-AF647 and analyzed by flow cytometry. The results are calculated based on the median fluorescence intensity observed in the patient's serum compared to negative control serums.
The GAT method evaluates the functional ability of donor granulocytes to agglutinate in response to antibody binding from the patient's serum. The results are manually observed using bright-field microscopy and scored based on the percentage of cell aggregates present.(Chiaretti S, Burton M, Hassel P, et al. Human neutrophil antigen 3 genotype impacts neutrophil-mediated endothelial cell cytotoxicity in a two-event model of TRALI. Blood Transfus. 2022;20(6):465-474. doi:10.2450/2022.0013-22)
Day(s) Performed
Tuesday, Thursday
Report Available
7 to 15 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
86021 x2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| LAGGN | Granulocyte Ab Screen, S | 105285-1 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| LAGG2 | GIFT/GAT Interpretation | 105288-5 |
| LAGG3 | GIFT Result | 105286-9 |
| LAGG4 | GAT Result | 105287-7 |