Research On PR1 Specific Cytotoxic T Lymphocytes Of 28 Cases HLA-A0201 Positive Chronic Myelogenous Leukemia

Objective:To evaluate the proportion of PR1 specific CTL in the peripheral blood of patients with chronic myelogenous leukemia(CML), and to investigate the correlation among the proportion of PR1 specific CTL,curative effect, and prognosis of patients with CML at different phases.Besides, to discuss whether we could use PR1 peptide as the following immune therapeutic method for patients who have achieved the standard of stop treatment.Methods:The soluble HLA-A0201-PR1 tetramer and Flow cytometry were used to determine the proportion and the frequency of PR1 specific CTL in peripheral blood from 28 HLA-A0201 positive CML patients; the proportion was compared among different phases of the disease. Results:1. There is a negative correlation between PR1 specific CTL and PCR (BCR-ABL/ABL) 1S (r=-0.658,P<0.001).2. The frequency of PR1 specific CTL at 3M、6M、9M、12M、2Y、3Y、4Y、5Y、 6Y were (0.06±0.02)%、(0.10±0.02)%、(0.14±0.02)%、(0.16±0.02)%、(0.20± 0.03)%、(0.18±0.03)%、(0.18±0.01)%、(0.17±0.05)%、(0.18±0.03)% separately.The frequency of PR1 specific CTL at 3M、6M、9M、12M was statistically different (P<0.05), and they were statistically different with those at 2Y、3Y、4Y、Y、6Y(P<0.05). The frequency of PR1 specific CTL had no statistical different among 1Y、2Y、3Y、4Y、5Y、6Y(P>0.05).3. For patients who treated with IM 400mg qd, the frequency of PR1 specific CTL of high-risk was lower than those of low-risk and intermediate-risk patients. Conclusion:PR1 specific CTL can be detected in patients who achieved better curative effect, and it’s correlated with tumor burden, indicate that PR1 specific CTL maybe relate to the action of resisting leukemia, thus provide the evidence of using PRl peptide as a potential immune therapeutic schedule for patients who have achieved stable MR4.5 and MR5.0.