|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 2 | Page : 92-93
Evidence for an antagonistic effect of Anti-Lea on the reactivity of antibodies to M and N antigens
Sanmukh R Joshi, Ankita Sheladiya
Lok Samarpan Regional Blood Centre, Surat, Gujarat, India
|Date of Web Publication||6-Sep-2016|
Sanmukh R Joshi
Lok Samarpan Regional Blood Centre, Surat, Gujarat
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Joshi SR, Sheladiya A. Evidence for an antagonistic effect of Anti-Lea on the reactivity of antibodies to M and N antigens. Glob J Transfus Med 2016;1:92-3
|How to cite this URL:|
Joshi SR, Sheladiya A. Evidence for an antagonistic effect of Anti-Lea on the reactivity of antibodies to M and N antigens. Glob J Transfus Med [serial online] 2016 [cited 2017 Nov 20];1:92-3. Available from: http://www.gjtmonline.com/text.asp?2016/1/2/92/189875
The presence of multiple antibodies in a transfusion recipient not only poses problems in finding a compatible blood unit for transfusion but also exert difficulty in identification of specificity of the individual antibody involved. We have observed a unique problem in antibody identification in a 27-year-old recently delivered woman named HDG. She was typed as A1, Rh.D-negative, Le (a− b−), M− N+, had a positive antibody screen test with the presence of multiple antibodies including anti-Le a, anti-M, and anti-D.
In preliminary investigations, her serum reacted with most of the red cells in the panel, showing confusing reaction pattern. The variability in hemagglutination strength at different temperatures, some of the tests showing partial hemolysis and yet other red cells reacted with her serum by papain enzyme method at different phases. The results had indicated to a presence of multiple antibodies. It required an inclusion of multiple antigen-negative red cells in panel to identify the individual specificity. The inhibition pattern of anti-M was obvious due to the interference of the Lewis antibody, as there was no such interference of anti-D noticed when appropriate red cells of different D phenotypes were used in the test. [Table 1] shows that the anti-M (two examples, including the present case) and anti-N having titer values of >16 with red cell phenotype MM (M-homozygous), and NN (N-homozygous), respectively, yield a considerable fall in titer values when the patient's fresh serum was added. Anti-M and anti-N, showing a dosage effect, rendered nonreactive with the MN (heterozygous) red cell when mixed with the patient's fresh serum.
|Table 1: Inhibitory effect of the patient's serum on human anti-M and -N reagents|
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Immunoglobulin nature of anti-M and anti-Le a was found to be IgM, as their reactivity was abolished by the treatment of the serum using 2-mercaptoethanol. Anti-D was, however, typed as IgG since its reactivity had remained unaffected by 2-mercaptoethanol (the results are not tabulated).
The patients with the two different antibody specificities would react with the cells if both the corresponding antigens were simultaneously present on the cells or it would not react even if either of the antigens was present. This phenomenon was thought to be due to the synergistic effect being shown by the two antibodies. The present report describes a hitherto unknown phenomenon, wherein an antagonistic effect of an anti-Lewis on anti-M or anti-N antibodies was clearly visible.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Harmening DM. Part II. Blood grouping and serologic testing. In: Modern Blood Banking and Transfusion Practices. 6th
ed. Philadelphia: F. A. Davis Company; 2012. p. 226.