PATTERN OF ABO & RH BLOOD GROUPS IN MULTAN REGION

In this study six thousand young healthy voluntary blood donors of either sex belonging to Multan region comprising of 5476 males and 524 females, were included from “Blood Transfusion Center Nishtar Hospital Multan” and “Fatmid Blood Transfusion Center Multan”. The commonest blood group observed in this study was “B” with frequency of 36.95%. The next common was group “O” with frequency of 33.8% followed by group “A” with frequency of 21.92% and group “AB” 7.33%. The frequency distribution of Rh blood group shows that 92.17% of the subjects are Rh-positive and 7.83% are Rh-negative. There was statistically no significant difference in the frequency of ABO and Rh blood groups between the two sexes.


INTRODUCTION
The discovery of various blood group systems and the presence of blood group antigens on different cells of the body tissues have immense importance in transfusion medicine, genetics, medical jurisprudence, infertility problems, anthropology, haemolytic disease of the newborn (HDN), organ transplantation, oncology and association of different diseases with blood groups in medicine.
When blood transfusions from one person to another were first attempted, they were successful in some instances, but in many more, immediate or delayed agglutination and haemolysis of the red blood cells occurred.Soon it was discovered that the bloods of different persons usually have different antigenic and immune properties, so that antibodies in the plasma of one blood react with antigens on the surface of the red cells of another.Two particular groups of antigens are more likely than the others to cause blood transfusion reaction.These are ABO system of antigens and the Rh system.Frequencies of ABO & Rh blood groups vary throughout the world 1,4 as shown in tables 1 and 2. It has been observed that group B diminishes in frequency from East to West 5 .
ABO blood group data is well established in Karachi 6 and Lahore 78, areas, but no data is available from Southern Punjab and Multan population.The purpose of this study was to determine the pattern of ABO and Rh blood groups in Multan region.The results of this study will be of immense help in the future as we will know which blood group is in greater demand and donation for those particular groups may be requested accordingly.Similarly blood donor societies will get benefit from the results of this study as regards their priority of getting donations and storage of blood of various groups.Moreover this data will be helpful to study the prevalence of

SUBJECTS AND METHODS
In this study six thousand young healthy voluntary blood donors of either sex belonging to Multan region were included from "Blood Transfusion Center Nishtar Hospital, Multan" and "Fatmid Blood Transfusion Center, Multan."The clinical details of these subjects were recorded on a proforma.The blood samples were collected by venepuncture using sterile disposable syringes.
For ABO blood grouping the slide method 9 was used.One drop of anti-B serum (Trans clone "R" anti-B Sanofi diagnostic, Pasteur) was placed on the left side of the glass slide and one drop of anti-A serum (Trans clone "R" Anti-A Sanofi diagnostic, Pasteur) on the right side.One drop of unknown cell suspension was mixed with each of these antisera and the slide was tilted back and forth for 3 to 5 minutes.The drops were then covered with cover slips to facilitate examination under the microscope.Agglutination was observed within 2 to 5 minutes and the results were read as in the table 3.For Rh blood typing the method used was as mentioned by Dacie and Lewis 10 .As described in slide method for ABO grouping, one drop of unknown blood mixture was mixed with one drop of anti-D reagent (Trans clone R anti-D Fast M, Sanofi diagnostic Pasteur) on the slide and it was tilted back and forth for 3 to 5 minutes.The drop was covered with cover slips and seen under microscope.The results were taken as Rh positive if agglutination occurred because anti-D reagent agglutinates D antigen containing RBCs.
Fresh serum samples were tested for the presence of hepatitis B surface antigen using commercially available kit (Surase B-96 (OPD) general biologicals HbsAg EIA).The procedure was strictly followed as given in the kit.Negative and positive controls were run with each batch of samples.Anti-HCV antibodies were tested by commercially available kit (GBC Anti-HCV rapid tests, general biological corp.).Anti-HIV antibodies were tested by commercially available kit (HIVASE 1+2--96 general biologicals anti HIV 1+2 EIA).

RESULTS
A group of 6000 young healthy voluntary blood donors comprising of 5476 males and 524 females were tested for ABO and Rh blood groups.The frequency distribution of ABO blood groups is given in fig 1.It shows that Group B (36.95%) is the commonest followed by Group O (33.8%), and Group A (21.92%).Group AB (7.33%) is the least common.There was statistically no significant difference in the frequency of ABO blood groups between the two sexes as shown in the table 4. The frequency distribution of Rh-antigen shows that 92.17% of the subjects are Rh-positive and 7.83% are Rh-negative as shown in fig 2 .There was also statistically no difference in Rh-antigen expression between male and female sexes as shown in the table 5

DISCUSSION
The blood group systems are important in transfusion medicine, genetics, medical jurisprudence, infertility problems, anthropology, and haemolytic disease of the newborn (HDN), organ transplantation and oncology.In the medico-legal field blood groups are used for establishing paternity and for other identification purposes.Anthropologists have used the blood group system to study the origin of races and movement of population through the centuries.An association of given blood group with environmental diseases may tell about the genetic pressures which favour the survival of certain populations.The association of given blood groups with various diseases like peptic ulcers, malaria, HBsAg carrier state and carcinoma of stomach is also well established.
An individual blood group today, is as important as the national identity card.The obvious reason is the blood transfusion in cases of emergency.In medicine the life saving procedure of blood transfusion only becomes possible after the identification of the various blood group systems.The incompatibility of ABO and Rh blood  groups between mother and baby is responsible for jaundice, kernicterus and death in the newborn (HDN).Blood group data of a population is also important from a laboratory viewpoint, since it guides blood banks about the number and types of blood to be stored for transfusion services in cases of various catastrophes.
There is a worldwide variation in distribution of ABO and Rh blood groups.The commonest group observed in this study was "B" with frequency of 36.95%.Next common was group "O" with frequency of 33.8%, followed by group "A" with frequency of 21.92%, and group "AB" 7.33%.ABO blood group data is well established in Pakistan and neighboring countries as shown in the table 7.
The results of this study were similar to the study carried out in Lahore 8 in 1996 and in Punjab 11 in 1977.There was a slight difference from other two studies done in Karachi 6 and Lahore 7 but this was not statistically significant.The group "O" was the commonest in one study carried out in Lahore 7 .This difference of frequency in group "O" might be due to difference in sample size or geographical variation.The frequency of Rh blood group in this study was Rh +ve 92.17% and Rh -ve 7.83%.The results of this study are comparable to other studies carried out one in this region as shown in table 8.However, there was statistically no difference between the ABO and Rh blood group frequency in both sexes.

Table 1 :
Frequency of ABO phenotypes in selected populations.

Table 2 :
Frequency of Rh blood groups in selected population.

Table : 3
: Anti-sera of ABO blood group . The expression of Rh-antigen frequency in each ABO group is shown in the table 6 and fig 3. Out of 6000 healthy voluntary blood donors, 202 were HBsAg positive.

Table 4 :
Frequency of ABO blood groups in both sexes.

Table 5 :
Frequency of Rh-antigen expression between male and female.

Table 6 :
The expression of Rh-antigen frequency in each ABO group.

Table 7 :
Frequency of ABO blood group in Pakistan and neighbouring countries.

Table 8 :
Frequency of Rh blood group in different cities.