1. TO STUDY THE PREVALENCE OF EIGHTEEN CLINICALLY SIGNIFICANT BLOOD GROUP ANTIGENS IN BLOOD DONORS

2. INTRODUCTION
The International Society of Blood Transfusion (ISBT) recognizes more than 300 Red Blood Cell (RBC) antigens that belong to 35 different recognized blood group systems
More than 50 RBC alloantibodies are known to cause hemolytic disease of fetus and new born (HDFN) and hemolytic transfusion reactions (HTR), especially in multiply transfused patients
For patients with multiple alloantibodies or with an alloantibody against a high frequency antigen, finding compatible units without knowledge of prevalence of the antigens in question is an extremely difficult task

3. INTRODUCTION
Availability of such units pose a challenge for all transfusion services because they cause delay in blood transfusion. Therefore, such donors with rare antigenic profiles need to be recognized beforehand
Studying the prevalence of clinically significant antigens in a relatively large local donor population will ultimately help transfusion services to provide safe blood easily without unnecessary delay
At present, being such a populous country, it is ironical that neither does India possess a national rare donor registry nor has it registered any rare donor with international registries like International Rare Donor Panel (IRDP)

4. REVIEW OF LITERATURE STUDY CONDUCTED AT ANTIGENS TYPED
NUMBER OF SAMPLES TYPED
AIIMS, New Delhi
ABO, D
9,280 continuous voluntary and replacement donors
C,E,c,e,K,k,Fya,Fyb,Jka,Jkb,M,N,S,s,Lea,Leb,Lua,Lub,P1
508 donors
Indraprastha Apollo Hospitals, Delhi
D,C,E,c,e,K,k,Fya,Fyb,Jka,Jkb,M,N,S,s
3073
GMC, Surat
D,C,E,c,e,K,k,Fya,Fyb,Jka,Jkb,M,N,S,s,Lea,Leb, Lua,Lub,P1
115 ‘O’ group donors
SVIMS, Tirupati
D,C,E,c,e
1000 healthy blood donors
PGI, Chandigarh
D,C,E,c,e,K
1240 regular repeat voluntary donors of ‘O’ blood group
k,Fya,Fyb,Jka,Jkb,M,N,S,s,Lea,Leb, Lua,Lub,P1,Xga
317 random donors amongst 1240
GMC, Chandigarh
C,E,c,e,k,Fya, Fyb,M,N,S,s
1000 healthy regular, repeat voluntary donors

5. AIMS AND OBJECTIVES Primary Objective
To study the prevalence of 18 clinically significant blood group antigens in blood donors
Secondary Objective
To motivate and create a database of accessible volunteer O blood group donors who have rare antigenic profile to provide blood in emergencies to rare blood group patients
To register rare donors with international bodies like AATM (Asian Association of Transfusion medicine), India and IRDP (International Rare Donor Panel) run by IBGRL (International Blood Group Reference Laboratory), Bristol, UK

6. STUDY DESIGN
A cross-sectional, analytical study was conducted from October 2016 to May 2018 in the Department of Transfusion Medicine at at a large tertiary care hospital

7. INCLUSION CRITERIA
Using the sampling method given below, those donors were included who gave consent to participate in the study
SAMPLING METHOD
It was planned to include a minimum sample size of For this a random systematic sampling method was adopted. In this, varying sampling intervals were used on different days of the week
These intervals were decided using computer generated random numbers. On each day, the first sample was selected randomly and thereafter the sampling continued with above mentioned intervals subject to a maximum of 80 per week
Day of the week
Sampling interval
Monday 8
Tuesday 3
Wednesday 4
Thursday 2
Friday
Saturday 5
Sunday

8. EXCLUSION CRITERIA
All Direct Antiglobulin Test (DAT) positive samples were excluded
All samples screened positive by the antibody screening panel were excluded
All samples screened positive for HBsAg, Anti - HCV, Anti – HIV I & II, Malaria and Syphilis were excluded

9. MATERIALS AND METHODS
C, c, E, e, Jka, Jkb, Lea, Leb, P1 phenotyping was performed in Reverse Diluent cards (Ortho Clinical Diagnostics, UK) by CAT using anti C, anti c, anti E, anti e, anti Jka, anti Jkb, anti Lea, anti Leb, anti P1 respectively (BioClone, Ortho Clinical Diagnostics, UK)
K, k, Fya, Fyb, S, s phenotyping was performed in AHG Polyspecific cards (Ortho Clinical Diagnostics, UK) by CAT using anti K, anti k, anti Fya, anti Fyb, anti S and anti s respectively (BioClone, Ortho Clinical Diagnostics, UK)
M and N phenotyping was performed by CTT using anti M and anti N respectively (BioClone, Ortho Clinical Diagnostics, UK)
Quality control:
Each antisera was tested with the corresponding antigen positive (heterozygous and homozygous) and negative red cells at the beginning of each month and also when the lot was changed except anti-K which was tested only with K+k+ and K-k+ cells

10. SELECTION OF DONORS FOR STUDY USING INCLUSION CRITERIA
CONSENT FOR PARTICIPATION IN STUDY
TESTS FOR INFECTIOUS DISEASE MARKERS AND BLOOD GROUPING, ANTIBODY SCREENING AND
DIRECT ANTIHUMAN GLOBULIN TEST
APPLICATION OF EXCLUSION CRITERIA
ANTIGEN TYPING
DATA COLLECTION
DATA COMPILATION
DATA ANALYSIS AND COMPARISON
CONCLUSION

11. STATISTICAL ANALYSIS
Antigen and phenotype frequencies were calculated and expressed as percentage
Gene frequency was calculated by Hardy Weinberg principle of population genetics

12. OBSERVATIONS AND RESULTS

13. OBSERVATIONS AND RESULTS

14. RESULTS
Antigen
Percentage (%)
Makroo et al
Thakral et al
Blacks
Caucasian D
93.80
93.6 -
92.0
85.0 C
83.50
87.0
84.76
27.0
68.0 E
19.77
20.0
17.9
22.0
29.0 c
54.90
58.0
52.82
96.0
80.0 e
98.38
98.0
98.3 M
75.89
88.8
75.39
74.0
78.0 N
62.04
65.4
61.51
75.0
72.0 S
59.66
54.8
56.47
31.0
55.0 s
82.84
88.7
87.38
93.0
89.0
Antigen
Percentage (%)
Makroo et al
Thakral et al
Blacks
Caucasian
Jka
84.22
81.4
82.65
92.0
77.0
Jkb
62.91
67.6
66.56
49.0
74.0
Fya
85.23
87.4
86.75
10.0
66.0
Fyb
59.15
57.7
56.15
23.0
83.0
Lea
15.18 -
20.82
Leb
67.91
60.57 P1
71.23
71.92 K
5.14
3.5
5.56
2.0
9.0 k
99.98
99.97
100
99.8

15. RESULTS

16. SECONDARY OBJECTIVES
All donors who were selected using the inclusion criteria, were encouraged to participate in the study and motivated for regular blood donations. All the donors gave consent for participating in the study and also for their recruitment in the voluntary donor database
A rare donor with D--/D-- type was identified serologically and confirmed by genotyping

18. CONCLUSION
This study might help enhance the confidence of blood banks and Transfusion Medicine specialists and reduce the turnaround time for finding appropriate units for patients with unexpected antibodies or with rare phenotypes
It paves a way for further research and building up of local donor registry that might collectively lead to development of a centralized national database of rare donors
This study has also helped turn zero to a whole number on the number of rare donors registered in the IRDP

19. THANK YOU!