Rh genotype

[gagpinks]

Hi 

We Received URGENT request for 1 unit of blood transfusion for 1 year old child who had previous transfusion at abroad due Thalassemia Major. 

This was patient 1st visit in the UK therefore Rh and K phenotype was not known .  As per guidelines Rh and K phenotype performed. 

Rh phenotype results obtained as below

C mf E 4+ c+4 e4+ K mf. (Probably R2r)

Because patients was previously transfused at other country sample was sent for genotype which will take 2 weeks to get results back. 

Due to clinical condition, patient, required urgent transfusion therfore with Haematology consultation 1 unit of blood C-K- blood issued by IAT xmatch.  Meanwhile sample was  sent for Rh genotype and results received  as C+E-c-e+ (R1R1). 

Totally different phenotype result

Why? 

I know patient had multiple  transfusion at abroad.  

But never seen. 

Thankfully we had consultant approval to issue C-K- blood. 

Lesson learned always involve clinical team to decide. 

Any further comments 

 

 

 

Edited November 7 by gagpinks

[SbbPerson ☆]

On 11/7/2024 at 2:01 PM, gagpinks said:

Hi 

We Received URGENT request for 1 unit of blood transfusion for 1 year old child who had previous transfusion at abroad due Thalassemia Major. 

This was patient 1st visit in the UK therefore Rh and K phenotype was not known .  As per guidelines Rh and K phenotype performed. 

Rh phenotype results obtained as below

C mf E 4+ c+4 e4+ K mf. (Probably R2r)

Because patients was previously transfused at other country sample was sent for genotype which will take 2 weeks to get results back. 

Due to clinical condition, patient, required urgent transfusion therfore with Haematology consultation 1 unit of blood C-K- blood issued by IAT xmatch.  Meanwhile sample was  sent for Rh genotype and results received  as C+E-c-e+ (R1R1). 

Totally different phenotype result

Why? 

I know patient had multiple  transfusion at abroad.  

But never seen. 

Thankfully we had consultant approval to issue C-K- blood. 

Lesson learned always involve clinical team to decide. 

Any further comments 

 

 

 

 

May I ask what was the patient's type and screen result prior to any transfusion? 

 

[Townsend]

We would honor the molecular typing and provide E-, c-, and K- red cells for this patient moving forward.  Your serologic typing results are not valid due to recent transfusion, and this isn't an uncommon genotype for a thalassemia patient.  Unfortunately this means that the patient received c pos units (when you gave C-, K- red cells), but that was the best you could do without knowing that information before the first transfusion was ordered at your facility.  We come across this frequently with new/relocated sickle and thalassemia patients.

[Yanxia]

I just can't understand why the phenotype gives 4+ of c antigen when the genotype is c neg.

[gagpinks]

On 11/14/2024 at 7:13 AM, SbbPerson said:

 

May I ask what was the patient's type and screen result prior to any transfusion? 

 

Patient blood group is A Rh D positive and antibody screen negative 

[gagpinks]

On 11/15/2024 at 2:26 PM, Townsend said:

We would honor the molecular typing and provide E-, c-, and K- red cells for this patient moving forward.  Your serologic typing results are not valid due to recent transfusion, and this isn't an uncommon genotype for a thalassemia patient.  Unfortunately this means that the patient received c pos units (when you gave C-, K- red cells), but that was the best you could do without knowing that information before the first transfusion was ordered at your facility.  We come across this frequently with new/relocated sickle and thalassemia patients.

How do you deal with this situation at your end?

[gagpinks]

On 11/16/2024 at 6:43 AM, Yanxia said:

I just can't understand why the phenotype gives 4+ of c antigen when the genotype is c neg.

I guess patient might have multiple transfusion c+ in home country where they don't perform Rh phenotype.  

[SbbPerson ☆]

1 hour ago, gagpinks said:

Patient blood group is A Rh D positive and antibody screen negative 

Aah okay, I guess you answered your own question. The mixed field C result is perhaps due to the dual population of blood transfused. Some may have been C+ and some C-. c+ is a common antigen, almost 80% of Caucasians have it.  That could explain the strong c 4+.  Most place don't do phenotyping after multiple transfusions because of possible dual rbc population , so yes, Townsend is right, "honor the genotyping and provide E-, c-, and K- red cells for this patient moving forward"(Townsend). 

Edited November 21 by SbbPerson