Each transfusion carries a risk of transmitting blood-borne pathogens, including mainly human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV) and syphilis [1]. With every unit of blood there is a 1% chance of transfusion associated problems including transfusion transmitted diseases [2]. Host genetic and environmental factors may be important in the genesis of diseases [3]. Mourant et al., concluded that the differences in frequencies of blood Groups A and B are the result of random genetic drift and founder effects as well as of natural selection, arising from differences in fitness between the various blood groups [4]. The ABO blood group has been previously found to be associated with the risk of several malignancies, including gastric cancer, pancreatic cancer, epithelial ovarian and skin cancer [5]. Interaction of micro–organisms and RBC membrane is probably because of antigenic similarity, adherence through specific receptors or modulation of antibody response [6].
This study was done to know the seroprevalence of TTIs in different blood group in the national capital region (NCR) and to find out if there is any predisposition of infections to the blood groups.
Material and Methods
Study setting and design: This retrospective study was conducted at the blood bank of School of medical sciences and research, Sharda University, Greater Noida, NCR, for four years from January 2008 to January 2012. Sera of 6000 apparently healthy donors from different age groups and from different localities were screened.
Ethical clearance is done.
Data collection: The outcome variable was the serological report of the individual whether positive or negative or any TTIs.
Sample Collection and Lab Testing: The required sample was collected after informed consent from the donor and tested for Anti–HIV -1 & 2,HBsAg & anti – HCV using the appropriate Enzyme linked immunosorbent assay (ELISA) technique supplied by J.Mitra & Co.Ltd. The seropositive samples were again tested on ELISA kits of RFCL &/or BIORAD for further confirmation & ruling out any false positive or false negative results. The rapid plasma regain (RPR) test was used for estimation of syphilis infection.
Data Management and Statistical Analysis: Data entry was carried out by using Microsoft office excel worksheet and analysed by percentage and comparison.
Results and Observations
The seroprevalence rates of TTIs according to the various blood groups and Rh factor is given in [Table/Fig-1].
Distribution of seropositive blood donors based on blood groups
| Blood group | Total donors | Anti–HIV | Anti–HCV | HBsAg | VDRL |
|---|
| A positive | 1349 | 03 (0.222%) | 19 (1.408%) | 25 (1.853%) | 09 (0.667%) |
| A negative | 93 | 01 (1.075%) | – | 02 (2.1505%) | 01 (1.075%) |
| B positive | 1964 | 05 (0.2545%) | 24 (1.221%) | 25 (1.2729%) | 04 (0.2036%) |
| B negative | 159 | – | 03 (1.886%) | 02 (1.2578%) | – |
| O positive | 1856 | 02 (0.1077%) | 26 (1.4008%) | 30 (1.616%) | 08 (0.4310%) |
| O negative | 125 | – | 01 (0.800%) | 02 (1.6%) | – |
| AB positive | 429 | – | 04 (0.9324%) | 09 (2.097%) | 04 (0.932%) |
| AB Negative | 25 | – | – | – | – |
| Total | 6000 | 11 (0.1833%) | 77 (1.2833%) | 95 (1.5833%) | 26 (0.4333%) |
Discussion
Association between blood groups and diseases is not something new. Diseases like peptic ulcer, gastric carcinoma, erythroblastosis foetalis, coronary artery diseases and venous thromboembolism, neuroendocrine tumors in MEN type 1, have shown their association with various blood groups. Evidence collected by David J. Anstee showed that selection by infectious diseases at the level of the ABO and secretor genes is persuasive but for other blood group antigens, founder effects appear more likely to account for the distribution of blood group polymorphisms [7].
The study was done on the samples of 6000 apparently healthy human blood donors and it was found that “yes”, there does seem to be a preference of a particular infection to a particular blood group.
The NEGATIVE blood groups were found to be more prone to TTIs.
More patients with blood Group A negative were found to be affected with HIV, HBsAg and VDRL while blood Group B negative was more common in patients affected by HCV
In a study conducted in Karnataka, India. A. Banu reported that “O Rhesus positive” was the most prevalent blood group in both adult (40.13%) and paediatric (43.33%) HIV seropositives [8].
Omar and co-workers reported that seroprevalence of HBs Ag and HCVAb were found to be higher in donors who has blood group O and lowest in blood group AB donors, while the distribution of Rh in hepatitis infections was higher between Rh positive donors [9]. Kumar and associates reported that the highest prevalence of HIV and HBVinfection were found in individuals with blood group O and Rh positive [10].
In an analysis for sero-prevalence of antibodies to HIV, HBV and syphilis and its relationship to blood group in healthy Nepalese males, Joshi and Ghimire showed a tendency of high affinity of those diseases in the subjects with O “positive” blood group. However, no real association of those infections was found with the blood group (HIV: X2=0.902, p=0.99; HBsAg: X2=1.212, p=0.99; RPR: X2=3.975, p=0.789 [11].
Not much studies have been reported establishing relation between ABO and Rh blood group system. Sathe et al conducted a study in Aurangabad but reported that “There is no evidence of any association between sero-positivity for syphilis and ABO blood groups” [12].
The results of given study is not in agreement with other studies reported on association of Transfusion transmitted infection with ABO and Rh-system blood group. Most of similar studies have reported that blood group “O” and “Rhesus positive” is more prone to TTI. The probable reason may be that the sample size in given study is large as compared to other similar studies reported in the text.
Conclusion
This study clearly shows that there is preference for negative blood groups by the TTIs and even the specificity of a particular infection to a particular blood group is noted.
Other similar large scale studies are required to find out how can this association help us to improve our screening programmes?
Can particular blood groups be categorized as high risk donors?
Should they be given some extra attention while screening?
Should such people be otherwise also advised in good faith to get their blood tested for TTIs even if they do not intend to donate?
What about the list of second choice blood groups which are transfused considering them safer.
How safe is to routinely transfuse them in other emergency conditions?
What about the so called universally safe O – negative, the exchange transfusions done in newborns in the window period.
Food for thought and follow up….