|Year : 2017 | Volume
| Issue : 1 | Page : 34-37
Making type and screen policy an essential component of pretransfusion testing: Need of the hour in India
Rasika Setia1, Prerna Sachdeva1, Satyam Arora1, Anil Handoo2, Meenu Kapoor1
1 Department of Transfusion Medicine, BLK Super Speciality Hospital, New Delhi, India
2 Department of Hematology, BLK Super Speciality Hospital, New Delhi, India
|Date of Web Publication||22-Mar-2017|
Department of Transfusion Medicine, BLK Super Speciality Hospital, New Delhi
Source of Support: None, Conflict of Interest: None
Introduction: “Type and screen” policy involves the prior determination of patient blood group and antibody screening at the time of admission irrespective of the need of the blood transfusion to the patient. Materials and Methods: As a part of our retrospective analysis, we have evaluated our data from January 2014 to June 2016. Blood grouping was done by column agglutination technology (CAT) using DiaClon ABO/D+ Reverse Grouping cards (BIO-RAD, Switzerland). Antibody screening and identification were done using three cell panels (ID-DiaCell I-II-III Asia panel by BIO-RAD, Switzerland) and 11 cell panels (ID-DiaPanel-P by BIO-RAD, Switzerland) on CAT with LISS/Coombs cards. Results: A total of 17,896 patients requests for “type and screen” were received by the department during the study. Out of which 201 (1.12%; 1 in 89 patients) patients were found to have positive antibody screen. Out of 201 patients (132 females; 69 males); mean age group of 45.6 years (range: 1 day–85 years). Out of 201, 145 patients developed single antibody, 15 patients had double antibody, and in 41 positive antibody screens the specificity of alloantibodies were not identified either due to an interfering autoantibody (n = 10) or the specificity was not resolved on extended panels (n = 31) even with enzymes. Conclusion: “Type and screen” policy helps in timely blood group typing of the patients and providing enough time for the blood bank to arrange for blood. Our analysis shows the presence of an alloantibody in every 89 requests received for “type and screen.”
Keywords: Alloantibody, antibody screening, autoantibody, computer cross-matching, type and screen policy
|How to cite this article:|
Setia R, Sachdeva P, Arora S, Handoo A, Kapoor M. Making type and screen policy an essential component of pretransfusion testing: Need of the hour in India. Glob J Transfus Med 2017;2:34-7
|How to cite this URL:|
Setia R, Sachdeva P, Arora S, Handoo A, Kapoor M. Making type and screen policy an essential component of pretransfusion testing: Need of the hour in India. Glob J Transfus Med [serial online] 2017 [cited 2020 Aug 6];2:34-7. Available from: http://www.gjtmonline.com/text.asp?2017/2/1/34/202712
| Introduction|| |
Pretransfusion compatibility testing involves cross matching the donor red cells with patient plasma to rule out the possibility of incompatible transfusion. Besides ABO compatibility pretransfusion testing (PTT) includes detection of clinically significant red blood cell alloantibodies in patients as well. “Type and screen” policy includes ABO and Rh typing of patient's red cells and screening patient's plasma for the presence of any unexpected alloantibody at the time of admission irrespective of his/her blood requirements. One of the initial studies which evaluated this policy showed that 99.99% of ABO compatible red cells would be compatible in an anti-human globulin cross match if prior antibody screen is negative and patient does not have any history of unexpected antibodies. As many hospitals across India have implemented this policy, we have also looked back and analyzed our outcomes since the “type and screen” policy implementation. The aim of this retrospective analysis is to evaluate the implementation of this policy as well as to calculate the frequency of positive antibody screen as an outcome.
| Materials and Methods|| |
This was a retrospective analysis to evaluate positive antibody screen incidence encountered since the implementation of “type and screen” policy at our hospital. The period of study was from January 2014 to June 2016. Results of type and screen tests ordered and positive antibody screens were evaluated based on the department from which these were ordered. “Type and screen” policy involved prior determination of patient blood group and antibody screening at the time of admission irrespective of the need of the blood transfusion to the patient. This policy was applicable to all the patients admitted to the hospital irrespective of the diagnosis or indication for admission.
Blood grouping was done by column agglutination technology (CAT) using DiaClon ABO/D+ Reverse Grouping cards (BIO-RAD, Switzerland). Antibody screening and identification were done using three cell panels (ID-DiaCell I-II-III Asia panel by BIO-RAD, Switzerland) and 11 cell panels (ID-DiaPanel-P by BIO-RAD, Switzerland) on CAT with LISS/Coombs cards (ID-Cards by BIO-RAD, Switzerland). In cases where an antibody screen was positive with a positive auto-control, the underlying alloantibody was ruled out using autoadsorption. Cases with an unresolved specificity of an alloantibody were advised transfusion with Rh- and Kell-matched coombs compatible units.
| Results|| |
A total of 17,896 patients requests for “type and screen” were received by the Department of Transfusion Medicine (Blood Bank) during the study. Out of which, 201 (1.12%; 1 in 89 patients) patients were found to have positive antibody screen shown in [Table 1]. Of 201 patients, 132 were females and 69 were male. The mean age group of the patients was 45.6 years (range: 1 day–85 years). Out of 201 patients with positive antibody screen, 145 developed single antibody, 15 patients had double antibody, and in 41 positive antibody screens the specificity of alloantibodies were not identified either due to an interfering autoantibody (n = 10) or the specificity was not resolved on extended panels (n = 31) even with enzymes [Table 2].
|Table 1: Details of number of requests for antibody screen received from the respective departments with their resolution and frequencies|
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|Table 2: Details of number of antibody identified and according to the respective departments|
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The frequency of positive antibody screen was maximum (1 in 15 requests) from hemato-oncology department followed by medical oncology (1 in 35 requests), obstetrics and gynecology (1 in 63 requests). Neonatology and pediatrics department had a 1 in 31 requests positive for an antibody though all positive antibodies were found in samples from neonates admitted for exchange transfusion for hemolytic disease of the newborn due to Rh incompatibility with the mother.
Out of 160 alloantibodies identified, most common specificity (51.8%) of the antibody was against the Rh blood group system which included 14 alloantibodies in pairs and 69 single alloantibodies. Alloantibody against Rh system was followed by alloantibody against MNS, Kell, Mi(a), and Lewis blood group systems as shown in [Table 2]. Fifteen patients in total who developed dual alloantibodies (14 against Rh and one against S + K); eight were from obstetrics and gynecology whereas five and two from hemato-oncology and orthopedics departments, respectively.
Most of the antibody identified were IgG type (123 out of 145 single antibodies) whereas there were 22 patients (10 anti-M, 11 anti-Lea, and 1 anti-P) with the antibody of IgM in nature (confirmed with Dithiothreitol [DTT] method) and which also interfered with reverse grouping. Out of 201 patients, 162 patients (80.5%) had a history of previous transfusion or pregnancies, rest 39 patients had naturally occurring alloantibody. Naturally occurring antibodies were against M, Mi(a), P and Le(a) antigens.
| Discussion|| |
This retrospective analysis shows our experience with implementation of “type and screen” policy at a tertiary care hospital in India. Antibody screen along with blood group typing has been an essential part of PTT guidelines for long. Very limited data are available on the implementation of this policy from India with only few studies have been published.,,,, Chaudhary and Agarwal  studied 2026 requests for antibody screening and 26 cases (1.28%) were positive whereas study published by Pathak et al. showed only 68 patients (0.15%) with antibody screen positive out of 45,373 patients tested. In another recent study, out of 354 patients screened only four samples (1.1%) were positive for an alloantibody. Tiwari et al. reported antibody screening of 32,560 patients with antibody screen positive in 40 (0.12%).
The incidence of positive antibody screen depends on the type of patient population studied as well as the sensitivity of the methodology used. Positive antibody screen incidence in our study was 1.12%, which is close to the incidence of 1%-1.5% reported worldwide., Another study from India has also reported as high as 3.4% antibody screen positivity, but the patient population was multi-transfused in that analysis. The incidence of a positive antibody screen in our study was 6.3% in multi-transfused haemato-oncology patients and 2.8% in medical-oncology patients which is comparable to incidence of 9.1% reported in a study by Tiwari et al.
Most common specificity of alloantibody identified was from Rh blood group system in all the studies published from Indian ,,, and in our study as well. Higher incidence of antibodies against Rh blood group system is due to the absence of universal anti-D immunization in India. Rh was followed with MNS and Kell blood group systems against which the alloantibodies were identified.
Seventeen previously untransfused patients (0.09%) presented with anti-Mi(a) antibody, indicating the frequency of this naturally occurring alloantibody in our study population. Antibody against Mi antigen has been under reported from India due to the absence of antigen on the antibody screening panel available till recent past. Prathiba et al. have reported up to 0.2% anti-Mi(a) alloantibody incidence in Indian patient population  whereas a recent study from Delhi  reported 0.1% incidence of anti-Mi(a) in donor population (naturally occurring). In this study, anti-Mi(a) was identified on ID-DiaCell I-II-III Asia panel by BIO-RAD but was not confirmed on 11 cell panels (ID-DiaPanel-P) due to the absence of any positive cell for Mi(a) in 11 cell panel. Hence, a positive three cell panel (only for cell III, positive for Mi(a)) followed by negative 11 cell panel was considered anti-Mi(a). The patient identified with anti-Mi(a) antibody were transfused coombs compatible red cell units. Screening for anti-Mi(a) alloantibody is a routine practice in countries like Taiwan as it has shown to be of IgG nature and can result in transfusion reactions.
As many as 41 positive antibody screens were not resolved with respect to their specificity of the antibody on extended 11 cell panel. Ten out of forty-one had interference from an accompanying autoantibody. In rest 31 patients, the specificity of the antibody was not conclusively identified on extended 11 cell panel and with enzymes. This can be due to an antibody in an evolving phase or required a reference laboratory to confirm. All these patients were advised Rh- and Kell-matched coombs compatible units for transfusion.
Type and screen policy offers multiple advantages in managing and arranging compatible red cell units for patients in tertiary care centers. It provides enough time for the immunohematology laboratory to complete the workups to confirm the alloantibody and also to arrange compatible units for transfusion. It also allows the treating physicians and transfusion medicine specialist to discuss the best transfusion strategies in case the antibody is not identified or when compatible blood is not available. This policy also forms the base for the newer concept of computer cross-match for which this policy is mandatory. Our analysis also highlighted the need to have the indigenous screening cell panel as there can be alloantibody against numerous antigens specific to our populations which we need to identify and study.
The limitation of our study was following: complete workup of all these positive antibody screens was not done such as resolution of unresolved positive antibody screen and titration of the antibody when they were identified. As well as DTT treatment was not done on the entire positive antibody screen samples which would have helped us to detect mixture of IgG and IgM type of antibodies. Patient details such as diagnosis, number of transfusions in the past, and number previous pregnancies were also not studied. Another important part was the follow-up of these patients was not documented as it would have helped us to study the outcome posttransfusion of compatible units (antigen negative) in terms of reduction of antibody titer or development of any new alloantibody.
| Conclusion|| |
Our retrospective analysis offers an overview of outcome of implementing the “type and screen” policy. Overall frequency and incidence of a positive antibody screen (1 in 89; 1.12%) are fairly less, but in subgroups (e.g., hemato-Oncology) it is as high as 1 in 15 patients (6.3%). These analyses are important in evaluating the outcome of implementing a new policy as well as framing guidelines for the future transfusion practices across the country.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]