Exosomes as Prognostic Markers in DLBCL
Evaluation of exosomal nucleic acids can also provide additional prognostic information. Feng et al. found that circulating exosomal expression of miR-99a-5p and miR-125b-5p were significantly higher in chemoresistant vs. chemosensitive DLBCL patients (p<0.001) (97). Determination of predictive value of these miRNA using ROC curve analysis showed that the area under the curve (AUC) values of miR-99a-5p, miR-125b-5p, and IPI scores were 0.744 (p < 0.001), 0.7802 (p < 0.001), and 0.6308 (p < 0.05), respectively. The combined predictive value of miR-99a-5p and IPI score, had AUC of 0.8326 (p < 0.001) while that of miR-125b-5p combined with IPI score, had an AUC of 0.8143 (p < 0.001). This suggests that determination of exosomal expression of miR-99a or miR-125b-5p, when combined with IPI may be a robust way to predict response to therapy. Zare et al. observed a significant increase in exosomal miR-155 levels in refractory/relapsed DLBCL patients compared to responding patients or patients still on R-CHOP therapy (98). They also observed a higher concentration in refractory/relapsed patients.