Profile of Inflammation-Associated Proteins in Early Post-Transplant Samples of Patients After Allogeneic Hematopoietic Stem Cell Transplantation: a Preliminary Study

Multiplex Proteomics in the Identification of Potential Biomarkers of Very Severe Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease in Allogeneic Hematopoietic Cell Transplant Patients Treated with Defibrotide

INTRODUCTION

Despite well-established clinical criteria for diagnosis of sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) following allogeneic hematopoietic cell transplantation (HCT), there is a lack of established diagnostic protein biomarkers.

METHODS

Prospective samples were collected from patients with very severe SOS/VOD at diagnosis and days +3, +7, +14, and +30 post-initiation of defibrotide. Samples from age-matched controls with no VOD were collected at days +14, +30, +60, +90, and +180 following allogeneic HCT. Serum samples were analyzed for 2,925 protein levels by antibody-based proximity extension assay (PEA). Mean differences in the log-transformed abundance values were compared using t tests in a volcano plot.

RESULTS

Five patients with very severe SOS/VOD and 5 control patients were compared. Ten proteins were identified that showed a statistically significant and log-transformed 3-fold increase in concentration. They were CALCA, CCL20, GPR37, IGFBP4, IL1RL1, SLC39A14, SPINK4, FABP3, MYL3, and CHCHD10. Four different proteins, namely, CD83, leukocyte associated immunoglobulin-like receptor 2 (LAIR2), CD7, and HEM6 showed a significant decrease with defibrotide treatment. SOS/VOD resolved in 80% (n = 4) of patients, while 1 patient deceased due to SOS/VOD.

CONCLUSION

PEA technology identified 10 proteins that were significantly elevated in patients with very severe SOS/VOD. Prospective studies in a larger cohort using this technology may be able to conclusively identify diagnostic protein biomarkers for SOS/VOD.

Multiplex proteomics using proximity extension assay for the identification of protein biomarkers predictive of acute graft-vs.-host disease in allogeneic hematopoietic cell transplantation

OBJECTIVES

Allogeneic hematopoietic cell transplantation (HCT) is associated with acute graft-vs.-host disease (aGVHD). The presented study applied a novel multiplex antibody-based proximity extension assay (PEA) proteomic platform that can detect thousands of serum proteins simultaneously for the identification of potential biomarkers of aGVHD.

METHODS

Serum samples from 28 patients who underwent allogeneic HCT for acute myeloid leukemia (AML) were analyzed; 17 were diagnosed with grade II-IV aGVHD while 11 patients were not. Samples collected on day -6, day 0, +14, +30, +60 and +90 post-HCT were analyzed for the relative concentrations of 552 proteins. The concentration of each protein from baseline to the closest time point before onset of aGVHD, or to the latest time point in control patients, was documented.

RESULTS

Individualized analysis identified 26 proteins demonstrating ≥3-fold increase at aGVHD onset compared to baseline, eliminating proteins with a similar increase in controls. Another approach used paired t-testing and logistic regression that identified a four-marker panel, including SLAMF7, IL-1ra, BTN3A2 and DAB2, where individual log-likelihood ratios ranged from 3.99 to 8.15 (logistic regression, p=0.004-0.046). When combined, the four-marker panel demonstrated an area under the curve (AUC) of 0.90 (95% CI: 0.78-1.00; p=0.0006) with high negative predictive value of 81.8% and positive predictive value of 86.7%. All four markers play a physiological role in immune regulation. Among these, three were also present in the individualized analysis (SLAMF7, IL-1ra and BTN3A2).

CONCLUSIONS

We conclude that serum proteins identified using multiplex proteomics, particularly SLAMF7, IL-1ra, BTN3A2 and DAB2, may potentially predict aGVHD.