Effect of CTLA4 gene polymorphism on relapse probability among patients with acute leukemias after allogenic hematopoietic stem cells transplantation

Background. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is being widely applied as a therapy for hematological malignancies. The long-term outcome of allo-HSCT depends directly on the ability of cytotoxic T-lymphocytes to recognize and eliminate the residual tumor. CTLA-4 is one of the regulatory proteins that provide control over the development of the immune response. Polymorphisms in the CTLA4 gene can affect its function and the efficiency of the antitumor response.
The objective: to study the effect of non-synonymous single nucleotide polymorphism (nsSNP) c.49A>G in the donor CTLA4 gene on tumor control in the recipient of allogeneic hematopoietic stem cells (HSC).
Materials and methods. Donors of HSC were genotyped for nsSNP c.49A>G in the CTLA4 gene by the real-time polymerase chain reaction using the allele-specific primers. Genotyping data was validated by Sanger’s sequencing of 22 randomly selected samples. The overall survival, the event-free survival and relapse probability were calculated using the Kaplan–Mayer method. A log-rank test was used to assess the statistical significance of group disparities. A p-value of 0.05 was considered as significant.
Results. The frequencies of the CTLA4 gene c.49A>G polymorphism alleles in the observed population (102 healthy donors of HSC) correspond to the frequencies obtained by the “1000 genomes” project for the European population. The effect of the donor CTLA4 polymorphism on the tumor control was evaluated on the cohort of patients with acute leukemia after human leukocyte antigen (HLA) matched HSCT from an unrelated donor. It was shown, the three-year relapse-free survival was significantly lower for those patients who received grafts from a donor with the homozygous A/A state of nsSNP c.49A>G (p = 0.01), it was 12.7 % versus 62,8 % in group with c.49A>G G/G and A/G donor genotypes. The incidence of relapse was also significantly different for the group with A/A genotype and for the group with G/G or A/G genotypes of the nsSNP and equaled to 83.7 and 29.3 % respectively (p = 0.03).
Conclusion. Patients with acute leukemia, who underwent allo-HSCT from unrelated completely HLA-matched donors with c.49A>G G/G or A/G genotypes have the significantly lower risk of relapse than patients whose donors had the A/A genotype. These results suggest practicability of the nsSNP genotyping for the optimal donor selection.

1. Kolb H.J. Graft-versus-leukemia effects of transplantation and donor lymphocytes. Blood 2008;112(12):4371–83. DOI: 10.1182/blood-2008-03-077974. PMID: 19029455.

2. Shlomchik W.D. Graft-versus-host disease. Nat Rev Immunol 2007;7(5): 340–52. DOI: 10.1038/nri2000. PMID: 17438575.

3. Karandikar N.J., Vanderlugt C.L., Walunas T.L. et al. CTLA-4: a negative regulator of autoimmune disease. J Exp Med 1996;184(2):783–8. DOI: 10.1084/jem.184.2.783. PMID: 8760834.

4. van der Merwe P.A., Bodian D.L., Daenke S. et al. CD80(B7-1) binds both CD28 and CTLA-4 with a low affinity and very fast kinetics. J Exp Med 1997;185(3):393–403. DOI: 10.1084/jem.185.3.393. PMID: 9053440.

5. Krummel M.F., Allison J.P. CTLA-4 engagement inhibits IL-2 accumulation and cell cycle progression upon activation of resting T cells. J Exp Med 1996;183(6):2533–40. DOI: 10.1084/jem.183.6.2533. PMID: 8676074.

6. Kouki T., Sawai Y., Gardine C.A. et al. CTLA-4 gene polymorphism at position 49 in exon 1 reduces the inhibitory function of CTLA-4 and contributes to the pathogenesis of Graves’ disease. J Immunol 2000;165(11):6606–11. DOI: 10.4049/jimmunol.165.11.6606. PMID: 11086105.

7. Ligers A., Teleshova N., Masterman T. et al. CTLA-4 gene expression is influenced by promoter and exon 1 polymorphisms. Genes Immun 2001;2(3):145–52. DOI: 10.1038/sj.gene.6363752. PMID: 11426323.

8. Anjos S., Nguyen A., Ounissi-Benkalha H. et al. A common autoimmunity predisposing signal peptide variant of the cytotoxic T-lymphocyte antigen 4 results in inefficient glycosylation of the susceptibility allele. J Biol Chem 2002;277(48):46478–86. DOI: 10.1074/jbc.M206894200. PMID: 12244107.

9. Chistiakov D.A., Savost’anov K. V., Turakulov R.I. et al. Genetic analysis and functional evaluation of the C/T(-318) and A/G(-1661) polymorphisms of the CTLA-4 gene in patients affected with Graves’ disease. Clin Immunol 2006;118(2–3):233–42. DOI: 10.1016/j.clim.2005.09.017. PMID: 16297665.

10. Monne M., Piras G., Palmas A. et al. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) gene polymorphism and susceptibility to non-Hodgkin’s lymphoma. Am J Hematol 2004;76(1):14–8. DOI: 10.1002/ajh.20045. PMID: 15114591.

11. Ueda H., Howson J.M. M., Esposito L. et al. Association of the T-cell regulatory gene CTLA4 with susceptibility to autoimmune disease. Nature 2003;423(6939): 506–11. DOI: 10.1038/nature01621. PMID: 12724780.

12. Donner H., Rau H., Walfish P.G. et al. CTLA4 alanine-17 confers genetic susceptibility to Graves’ disease and to type 1 diabetes mellitus. J Clin Endocrinol Metab 1997;82(1):143–6. DOI: 10.1210/jcem.82.1.3699. PMID: 8989248.

13. Gonzalez-Escribano M.F., Rodriguez R., Valenzuela A. et al. CTLA4 polymorphisms in Spanish patients with rheumatoid arthritis. Tissue Antigens 1999;53(3):296–300. DOI: 10.1034/j.1399-0039.1999.530311.x. PMID: 10203024.

14. Hudson L.L., Rocca K., Song Y.W. et al. CTLA-4 gene polymorphisms in systemic lupus erythematosus: a highly significant association with a determinant in the promoter region. Hum Genet 2002;111(4–5): 452–5. DOI: 10.1007/s00439-002-0807-2. PMID: 12384790.

15. Gallardo D., Bosch-Vizcaya A., Rodríguez-Romanos R. et al. Donor CTLA-4 genotype modulates the immune response to minor histocompatibility antigen mismatches. Biol Blood Marrow Transplant 2017;23(12):2042–7. DOI: 10.1016/j.bbmt.2017.08.003. PMID: 28827064.

16. Azarian M., Busson M., Lepage V. et al. Donor CTLA-4 +49 A/G*GG genotype is associated with chronic GVHD after HLA-identical haematopoietic stem-cell transplantations. Blood 2007;110(13):4623–4. DOI: 10.1182/blood-2007-08-106385. PMID: 18056853.

17. Pérez-García A., la Cámara R.D., Román-Gómez J. et al. CTLA-4 polymorphisms and clinical outcome after allogeneic stem cell transplantation from HLA-identical sibling donors. Blood 2007;110(1):461–7. DOI: 10.1182/blood-2007-01-069781. PMID: 17384200.

18. Mohty M., Bay J.O., Faucher C. et al. Graft-versus-host disease following allogeneic transplantation from HLA-identical sibling with antithymocyte globulin-based reduced-intensity preparative regimen. Blood 2003;102(2):470–6. DOI: 10.1182/blood-2002-12-3629. PMID: 12649133.

19. Pascal L., Tucunduva L., Ruggeri A. et al. Impact of ATG-containing reduced-intensity conditioning after single- or doubleunit allogeneic cord blood transplantation. Blood 2015;126(8):1027–32. DOI: 10.1182/blood-2014-09-599241. PMID: 26160301.

20. Russell J.A., Turner A.R., Larratt L. et al. Adult recipients of matched related donor blood cell transplants given myeloablative regimens including pretransplant antithymocyte globulin have lower mortality related to graft-versus-host disease: a matched pair analysis. Biol Blood Marrow Transplant 2007;13(3):299–306. DOI: 10.1016/j.bbmt.2006.10.017. PMID: 17317583.

21. Warren E.H., Zhang X.C., Li S. et al. Effect of MHC and non-MHC donor/ recipient genetic disparity on the outcome of allogeneic HCT. Blood 2012;120(14): 2796–806. DOI: 10.1182/blood-2012-04-347286. PMID: 22859606.

22. Боголюбова А.В., Ефимов Г.А., Друцкая М.С., Недоспасов С.А. Иммунотерапия опухолей, основанная на блокировке иммунологических контрольных «точек» («чекпойнтов»). Медицинская иммунология 2015;17(5):395–406. DOI: 10.15789/1563-0625-2015-5-395-406. [Bogolyubova A.V., Efimov G.A., Drutskaya M.S., Nedospasov S.A. Cancer immunotherapy based on the blockade of immune checkpoints. Meditsinskaya immunologiya = Medical Immunology 2015;17(5):395–406. (In Russ.)].

23. Ijaz A., Khan A.Y., Malik S.U. et al. Significant risk of graft-versus-host disease with exposure to checkpoint inhibitors before and after allogeneic transplantation. Biol Blood Marrow Transplant 2019;25(1):94–9. DOI: 10.1016/j.bbmt.2018.08.028. PMID: 30195074.