Detection of lipoprotein lipase mRNA by real-time quantitative reverse transcriptase polymerase chain reaction in chronic lymphocytic leukemia / 中华检验医学杂志

ABSTRACT

Objective To investigate the expression level of lipoprotein lipase (LPL) mRNA in chronic lymphocytic leukemia (CLL) patients and evaluate the prognostic value of LPL in CLL Methods Quantitative real-time RT-PCR (qRT-PCR) was performed in 62 CLL patients, 10 normal controls using Taqman probe system. Association between LPL and other known prognostic factors, such as IgVH mutation status, ZAP-70 and CD38 expression, was determined using the Spearman correlation analysis. ROC curve was used to determine the cut-off value of LPL expression level, the positive and negative predictive value of IgVH mutation status. Results The correlation coefficients of the standard curves in qRT-PCR were not less than 0.990. The coefficients of variation (CV) of interrun assay and intramn assay were < 5%, and the sensitivity can reached 102 copies/μg RNA. The median LPL mRNA expression level was 0.006 0 (0-0.737 0) in 62 CLL patients, whereas in 10 normal controls LPL mRNA expression level was extremely low with the median level of 0 (0-0.000 4). The expression levels of LPL in three CLL samples after miniMACS-sorted CD19 positive B cells were 0.036 0, 0.075 0 and 0.197 0, which were similar to the levels before miniMACS-sorted (0.024 0, 0.074 0 and 0.225 0). LFL expression was significantly associated with IgVH mutation status (r=0.45, P<0.05) . LPL expression level in IgVH unmutated patients [0.006 0 (0.000 7-0.110 0)] was significantly higher than the level in IgVH mutated patients [0.002 0(0.000 2-0.027 0)] (U=96.5, P<0.05). LPL expression was also significantly associated with ZAP-70 (r=0.38, P<0.05), CD38 expressions (r=0.43, P<0.05). According to ROC curve, the cut-off of LPL mRNA expression level was 0.036, with a 66.7% specificity, a 72.4% sensitivity, a 51.8% positive predictive value (IgVH unmutated), and a 83.3% negative predictive value (IgVH mutated) for IgVH mutation status. Conclusions The qRT-PCR assay is reliable and sensitive. LPL mRNA expression significantly correlates with IgVH mutation status, ZAP-70 and CD38 expression, and could be a predictive marker of IgVH mutation status. Our data confirms a role for LPL as a novel prognostic indicator in CLL.