The Clinical Significance of Minimal Residual Disease Detected By Multiparametric Flow Cytometry in Acute Leukemia

Purpose

Minimal residual disease (MRD) detected by multiparametric flow cytometry is an important method for predicting relapse. According to the dynamic changes of MRD, through the first clinical treatment to prevent relapse in patients with elevated MRD levels.

Method

We retrospectively analyze dynamic level of MRD of 75 patients with acute leukemia in our department of hematology from January 2011 to June 2013. According to the retrospective data, to analyze the expression of LAIP and discuss the relationship between changes of MRD and prognosis.

Result

In this study there were 75 patients, including 20 patients with acute lymphocytic leukemia (ALL) and 55 patients with acute myeloid leukemia (AML). The specific LAIP were detected in 49 patients with AML, and the cross lineage and non-synchronous expression were majority. In cross lineage expression, detected frequency of CD45/CD34/CD33/CD13/CD56 was highest, accounted for 67.3% (33/49). In non-synchronous expression, CD45/CD34/CD117/CD33/CD64 accounted for 57.1% (28/49). In 20 patients with ALL, there were 16 patients with B-ALL and 4 patients with T-ALL. The specific LAIP were detected in all of the patients. In patients with B-ALL, detected frequency of CD45/CD19/CD22/CD10/CD13 was highest, accounting for 43.8% (7/16). In abnormal quantity of antigens, CD45/CD19/CD22/CD10/CD38 was the most common type, accounting for 50%. The abnormal expression of CD7/TDT was detected in four patients with T-ALL. In monitoring period 7 patients relapsed. We analyzed the relationship between the clinical data and replase. The results showed that level of peripheral hemoglobin at diagnosis and the times of remission induction were significantly associated with replase (P=0.021 and P=0.017, respectively). To analyze the relationship between change of MRD and prognosis, the results showed that 0.05% as the threshold was significantly related with recurrence. 20 patients of persistent MRD≥0.05% had significant differences with 28 patients of persistent MRD<0.05% in replase free survival (P=0.005).

Conclusion

It has important significance to predict relapse in patients with acute leukemia by detecting minimal residual disease. Patients of MRD ≥ 0.05% should receive early intensive therapy or hematopoietic stem cell transplantation. Even patients without relapse, it should be closely monitor dynamic levels of MRD and highly vigilant extramedullary relapse.