miR-146a and miR-155 Expression Levels in Acute Graft-Versus-Host Disease Incidence.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment for numerous hematological malignancies. However, acute graft-versus-host disease (aGVHD) is still the major complication causing mortality. MicroRNAs (miRNAs) play a significant role in inflammation and have potential as prognostic and diagnostic biomarkers. This study investigated the role of two immune-specific miRNAs (miR-146a and miR-155) as biomarkers for aGVHD incidence in the peripheral blood of allo-HSCT patients prior to disease onset. The study showed that miR-146a and its statistical interaction with miR-155 at day +28 were predictive of aGVHD incidence. Interestingly, the expression levels of miR-146a and miR-155 negatively correlated with the transcription factor, SPI1 (PU.1gene) mRNA expression.

Elevated level of HSPA1L mRNA correlates with graft-versus-host disease.

Graft-versus-host disease (GVHD) can be a fatal complication of allogeneic stem cell transplantation (allo-HSCT). GVHD can be classified as acute (aGVHD: up to 100 days) or chronic (cGVHD: after 100 days) based on the time-point of disease occurrence. At present there are a limited number of biomarkers available for use in the clinic. Thus, the aim of this research was to evaluate the biomarker potential of the extensively studied Heat Shock Protein 70 family members (HSPA1A/HSPA1B and HSPA1L) at the messenger RNA (mRNA) level in acute and cGVHD patient cohorts. In the skin biopsies, HSPA1L mRNA expression was lower in patients with severe aGVHD (grades II-III) when compared to those with none or low grade aGVHD (grades 0-I) and normal controls. In whole blood, HSPA1L mRNA expression level was significantly (p = 0.008) up-regulated at 28 days post-transplant in cGVHD patients with a significant area under the curve (AUC = 0.773). In addition, HSPA1B expression in whole blood was significantly higher at 3 months post-transplant in both the aGVHD grade II-III (p = 0.012) and cGVHD (p = 0.027) patients. Our initial results in this small cohort show that quantifying HSPA1L mRNA expression in the whole blood of allo-HSCT patients at day 28 post-allo-HSCT may be a useful predictive biomarker for cGVHD.