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Test Code LABRHD Weak RhD Analysis Workup

Additional Codes

Test name in EPIC EPIC Test Code Mnemonic Versiti
Weak RhD Analysis Workup LABRHD WRhD 3040

 

Test Alias

RHD, Weak D, RhD

Useful For/Utility

Molecular testing intended to resolve a RhD typing discrepancy for pretransfusion and/or prenatal testing. RhD genotyping is recommended whenever a weak D phenotype is detected by routine Rh blodo typing of pregnant women, other females of childbearing potential (under the age of 50), and sickle cell patients.

Methodology

Serotyping, Multiplex Allele-Specific PCR and Gel Electrophoresis

 

Test Algorithm

Pregnant women and other females of childbearing potential whose Rh type is positive and reacts at 2+ or less in gel testing will have RhD genotyping performed if it has not already been done once. RhD genotyping may also be performed on chronically transfused patients with weak Rh testing results in gel in order to prevent allo anti-D formation.

Clinical Information

Some of the more than 500 RHD alleles lead to a reduced and variable expression of D antigenic epitopes on the red cell surface. Patients with these aberrant alleles may be mistyped by serology because many of the alleles do not react equally with all Rh D typing reagents. It is importnat to resolve RhD discrepancies to determine appropriate anti-D prophylaxis for pregnant women and the RhD status for transfusion recipients.

Specimen Requirements

Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA)

Specimen Volume: 5 mL

Specimen Minimum Volume: pediatric minimum 0.5 mL

Additional Information: Specimens will not be accepted on weekends or holidays.

Specimen Transport Temperature

Ambient/Refrigerate NO/Frozen NO

Day(s) Test Set Up

Monday through Friday

Performing Laboratory

Versiti

Test Classification and CPT Coding

D Antigen Typing: 86901; Weak RhD Analysis: 81479

 

Report Available

2 days

Reference Values

This complex test is ordered to resolve a Rh discrepancy (aka D antigen typing discrepancy). The molecular testing will identify Weak D Types 1, 2, and 3. These Weak D Types can be safely deemed Rh positive