Sir,
Normally, an individual has anti-A and anti-B antibodies present. Pregnancy, transfusion, transplantation, or injections of immunogenic material may cause immunization to red cell antigens. Sometimes, no specific immunizing event can be identified for the production of an antibody against a red cell antigen. Such antibodies are called naturally occurring antibodies.[1,2]
This study was a descriptive study done prospectively; it was carried out at the red cell serology laboratory of the department of immunohematology and blood transfusion over a period of 6 months from June to December 2014. This study was approved by the institutional ethics committee.
Blood samples collected in pilot tubes (ethylenediaminetetraacetic acid and plain) from 6372 voluntary blood donors (n = 6372) from outdoor blood donation camps who had no history of previous blood transfusion, pregnancy, organ or stem cell transplantation, or transfusion of immunogenic material were subjected to blood grouping and antibody screening in the fully automated immunohematology system “Qwalys-3 (Erythrocytes Magnetized Technology)” [Figure 1].
Figure 1.
Flowchart showing protocol followed in this study
The samples giving a positive result were subjected to manual antibody screening by column agglutination technology in commercially available three-cell antibody screening panel (Bio-Rad) with an autocontrol followed by antibody identification by extended eleven-cell panel if positive reaction on three-cell panel [Figures 2 and 3].
Figure 2.
Three-cell antibody screening panel
Figure 3.
Eleven-cell antibody identification panel
A total of 19 antibodies were detected with 7 cases of anti-M (male: 6, female: 1), 4 cases of anti-N (male: 4, female: 0), 2 cases of anti-K (male: 2, female: 0), 4 cases of anti-LFA (antibodies against low-frequency antigens) (male: 3, female: 1), 1 case of anti-P1 antibody (male: 1, female: 0), and 1 case of anti-Lea (male: 1, female: 0). Similar findings of naturally occurring such antibodies have been found in several other studies and mentioned in textbooks.[3,4,5,6,7,8]
The study had few limitations. Automated immunohematology system detected mainly IgG antibodies, so it was possible that many IgM antibodies might have missed. Antibodies against many low-frequency antigens which were not included in antigram of the automated system might have missed.
To conclude, people without any history of prior red cell immunization can develop alloantibodies which may or may not be clinically significant and can also cause blood grouping discrepancies or incompatible crossmatches. These may also be clinically significant so even in individuals with no prior history of blood transfusion or pregnancy antibody screening, and crossmatching by IAT method is a must. Computer or electronic crossmatches for the samples with a negative antibody screen should be avoided unless an emergency.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
References
- 1.Hamilton JR, Bailey DJ. Identification of antibodies to red cell antigens. In: Fung MK, Eder AF, editors. AABB Technical Manual. 19th ed. Bethesda: AABB Press; 2017. pp. 349–84. [Google Scholar]
- 2.LacCE. Naturally Occurring Antibodies vs. Immune Antibodies. [Last accessed on 2019 Nov 08]. Available from: https://www.labce.com/spg1867622_naturally_occurring_antibodies_vs_immu ne_antibodie.aspx .
- 3.Storry JR. Other protein blood groups. In: Simon TL, McCullough J, editors. Rossi's Principle of Transfusion Medicine. 11th ed. Oxford: Wiley-Blackwell; 2016. pp. 185–92. [Google Scholar]
- 4.Tondon R, Kataria R, Chaudhry R. Anti-M: Report of two cases and review of literature. Asian J Transfus Sci. 2008;2:81–3. doi: 10.4103/0973-6247.42695. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Coghlan G. Antibodies to Low incidence antigens. Transfus Apheresis Sci. 2009;40:199–202. doi: 10.1016/j.transci.2009.03.013. [DOI] [PubMed] [Google Scholar]
- 6.Ito K, Mastuo M. A further example of a probably-naturally-occurring anti kell (Kl) found in Japanese female donor. J Japan Soc Blood Transfus. 1980;26:299–300. [Google Scholar]
- 7.Garg N, Sharma T, Singh B. Prevalence of irregular red blood cell antibodies among healthy blood donors in Delhi population. Transfus Apher Sci. 2014;50:415–7. doi: 10.1016/j.transci.2014.03.004. [DOI] [PubMed] [Google Scholar]
- 8.Klein HG, Anstee D. Mollison's blood Transfusion in Clinical Medicine. 11th ed. Oxford: Blackwell; 2005. Other red cell antigen; pp. 209–52. [Google Scholar]