The value of circulating microRNAs for early diagnosis of B-cell lymphoma: A case-control study on historical samples

Abstract

MicroRNAs are small regulatory RNAs that are deregulated in a wide variety of human cancers, including different types of B-cell lymphoma. Nevertheless, the feasibility of circulating microRNA for early diagnosis of B-cell lymphoma has not been established. To address the possibility of detecting specific circulating microRNAs years before a B-cell lymphoma is diagnosed, we studied the plasma expression of microRNA first in pre-treatment samples from patients with diffuse large B-cell lymphoma and subsequently in repository samples from blood donors who later developed B-cell lymphomas. In addition, we studied the microRNA expression in the diagnostic lymphoma biopsy. The most strongly induced (miR-326) and suppressed (miR-375) plasma microRNA at diagnosis, when compared with healthy blood donors, were also substantially up- or down-regulated in plasma repository samples taken from several months to up to two years before the blood donors were diagnosed with B-cell lymphoma. Importantly, at these time points the donors had no signs of disease and felt healthy enough to donate blood. In conclusion, this first study of plasma microRNA profiles from apparently healthy individuals, taken several years before B-cell lymphoma diagnosis, suggests that plasma microRNA profiles may be predictive of lymphoma development.

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1

Flow diagram detailing sample collection and study design. We identified candidate plasma microRNAs in treatment naive patients newly diagnosed with DLBCL. The samples were collected as previously described. The deregulated microRNAs were subsequently used for screening of individuals later diagnosed with DLBCL, FL or HL from the DBDS cohort. *The 16 cases were picked because they had previously been examined using expression array on tumor. **The controls could not be matched completely because the DBDS cohort was limited to age 18–67 years. Consequently we selected random controls.

Figure 2

Screening cohort tumor microRNA expression a) and b). Expression levels in tumor of relevant microRNAs are plotted as intensity (median, 25% and 75% percentiles). Array data were normalized using robust multi-array average. Up-regulated c) and Down-regulated d) plasma microRNAs plotted as fold change (2−ΔΔCt) difference between cases and controls (median, 25% and 75% percentiles). RT-PCR data were normalized using miR-23a. Statistically significant difference (<0.0003) between cases and controls adjusted for age and sex in quantile regressions is marked with a *.

Figure 3

Conformational cohort plasma microRNA expression at diagnosis relative to  plasma microRNA expression in blood donor controls. Up-regulated a) and Down-regulated b) plasma microRNA plotted as fold change (2-ΔΔCt) difference between cases and controls (median, 25% and 75% percentiles). RT-PCR data were normalized using miR-23a. Statistically significant difference (<0.003) between cases and controls adjusted for age and sex in quantile regressions is marked with a *.

Figure 4

Diagnostic value of plasma microRNA levels. (a) ROC of miR-326, miR-199a-5p, miR-375, miR-21-5p, miR-155-5p and the predictive algorithm for DLBCL screening and confirmation cohorts. (b) ROC illustrating the sensitivity and 1-specificity of miR-326, miR-199a-5p, and miR-375 in addition to the predictive algorithm for B cell lymphoma compared to healthy controls in last DBDS sample before diagnosis.

Figure 5

Plasma microRNA expression values (fold change) for miR-326 in repository samples from blood donors diagnosed with B-cell lymphoma. Zero is the time of diagnosis at hospital. The blue dotted lines illustrate the range (variation in expression) in control samples.

Figure 6

Plasma miR-375 levels before diagnosis. Plasma microRNA expression values (fold change) for miR-375 in repository samples from blood donors diagnosed with B-cell lymphoma. Zero is the time of diagnosis at hospital. The blue dotted lines illustrate the range (variation in expression) in control samples.