Biomarkers of graft-vs-host disease: Understanding and applications for the future

Diagnostic and prognostic role of elafin in skin acute graft versus host disease: a systematic review

BACKGROUND AND OBJECTIVE

Graft versus host disease (GVHD) is the common complication seen after allogeneic hematopoietic stem cell transplantation (HSCT) and a pleomorphic syndrome that resembles autoimmune and other immunologic disorders, leading to profound immune dysregulation and organ dysfunction. The most common targets of GVHD are skin, gastrointestinal tract and liver. GVHD is classified as acute graft versus host disease (aGvHD) if it occurs within the first 100 days after HSCT and chronic graft versus host disease(cGVHD) if it occurs after day 100. The skin is most frequently and earliest affected by aGvHD, followed by the gastrointestinal tract and liver. An ideal biomarker would predict the onset and severity of clinical acute GVHD and help to direct management, and this is an area of active research regarding the use of biomarkers for diagnosis and prognosis of acute GVHD. Recently, elafin has been identified as a potential plasma biomarker for aGVHD.

METHOD

We searched the databases PubMed, Cochrane library, and medRxiv for all studies investigating the Diagnostic or prognostic role of elafin in GVHD. We set the search strategy incorporating the search terms, 'elafin', 'graft versus host', and 'GVHD', and operated using the Boolean operators 'AND', and 'OR'. Thus, retrieved articles were then exported on an Excel® sheet, and duplicates were removed. The systematic review was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. After selecting the study based on inclusion criteria, data on study characteristics and biomarker description was extracted on a pre-determined data extraction table on the Microsoft Excel version. The quality assessment of the included studies was determined using the QUIPS tool.

RESULT

The search revealed 547 studies and 6 studies that met the eligibility criteria of this review have been included. The major finding of our study is the significant elevation of elafin in skin aGVHD.

CONCLUSION

Elafin is a significant biomarker for diagnosis and prognosis of skin aGVHD and should be assessed within 2 weeks of the onset of the disease.

Verification of the Prediction Accuracy of a Biomarker-Based Prognostic for Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome (VOD/SOS) After Hematopoietic Cell Transplantation (HCT)

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation (HCT), especially in severe cases. Patient outcomes are improved with prompt treatment; however, diagnosing this disease is challenging as many clinical symptoms of VOD/SOS overlap with other post-HCT complications. A biomarker-based prognostic test for the assessment of VOD/SOS risk, termed "VODCheck" was developed in a previous study but has not yet been validated. This study aimed to validate the accuracy of VODCheck as a prognostic test for VOD/SOS in an independent cohort of patients. VODCheck incorporates hyaluronan (HA), angiopoietin-2 (ANG-2), and thrombomodulin (TM) based on their association with VOD/SOS, their analytical characteristics, and their ability to complement each other in a multivariate prognostic model. To validate VODCheck we measured plasma biomarker levels from a subset of patients enrolled in the control arm of a phase 3 study that tested VOD/SOS prophylaxis. We used a hierarchical design with prespecified primary (day 7), secondary A (day 15), and secondary B (day 1) hypotheses to verify the prognostic accuracy of VODCheck post-HCT. The cases of VOD/SOS (n = 22) were age-matched ∼1:3 with controls (n = 65). VODCheck was prognostic of VOD/SOS risk at all 3 time points with an area under the curve (AUC) of .815 (P < .001) for day 7, .836 (P < .001) for day 15, and .706 (P = .002) for day 1 post-HCT. A multivariate analysis confirmed the prognostic accuracy of VODCheck after adjustment for confounders such as age, VOD/SOS risk status, primary disease, and ozogamicin treatment. VODCheck was validated as an independent predictor of risk for VOD/SOS within 15 days post-HCT and appears to provide clinicians with actionable information to improve patient care.

Pathophysiology of acute graft-versus-host disease from the perspective of hemodynamics determined by dielectric analysis

BACKGROUND

Numerous reports have demonstrated that the pathophysiology of graft-versus-host disease (GVHD) during hematopoietic stem cell transplantation (HSCT) is closely related to vascular endothelial disorders and coagulation abnormalities. We previously presented the discovery of a principle and the development of a novel instrument for measuring whole blood coagulation. This was achieved by assessing the variations in the dielectric properties of whole blood.

AIM

To investigate how GVHD affects the changes of dielectric properties of whole blood in patients with HSCT.

METHODS

We examined the changes of dielectric properties of whole blood and erythrocyte proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis sequentially in patients with HSCT and compared it with clinical symptoms and inflammatory parameters of GVHD.

RESULTS

During severe GVHD, the dielectric relaxation strength markedly increased and expression of band3 decreased. The dielectric relaxation strength normalized with the improvement of GVHD. In vitro analysis confirmed that the increase of relaxation strength was associated with severe erythrocyte aggregates, but not with decreased expression of band3.

CONCLUSION

Severe erythrocyte aggregates observed in GVHD may cause coagulation abnor malities and circulatory failure, which, together with the irreversible erythrocyte dysfunction we recently reported, could lead to organ failure.

Machine learning applications and challenges in graft-versus-host disease: a scoping review

PURPOSE OF REVIEW

This review delves into the potential of artificial intelligence (AI), particularly machine learning (ML), in enhancing graft-versus-host disease (GVHD) risk assessment, diagnosis, and personalized treatment.

RECENT FINDINGS

Recent studies have demonstrated the superiority of ML algorithms over traditional multivariate statistical models in donor selection for allogeneic hematopoietic stem cell transplantation. ML has recently enabled dynamic risk assessment by modeling time-series data, an upgrade from the static, "snapshot" assessment of patients that conventional statistical models and older ML algorithms offer. Regarding diagnosis, a deep learning model, a subset of ML, can accurately identify skin segments affected with chronic GVHD with satisfactory results. ML methods such as Q-learning and deep reinforcement learning have been utilized to develop adaptive treatment strategies (ATS) for the personalized prevention and treatment of acute and chronic GVHD.

SUMMARY

To capitalize on these promising advancements, there is a need for large-scale, multicenter collaborations to develop generalizable ML models. Furthermore, addressing pertinent issues such as the implementation of stringent ethical guidelines is crucial before the widespread introduction of AI into GVHD care.

Novel therapies for graft versus host disease with a focus on cell therapies

Graft versus host disease (GVHD) can occur at any period post allogeneic hematopoietic stem cell transplantation as a common clinical complication contributing to significant morbidity and mortality. Acute GVHD develops in approximately 30-50% of patients receiving transplants from matched related donors. High doses of steroids are used as first-line treatment, but are unsuccessful in around 40% of patients, resulting in the diagnosis of steroid-refractory acute GVHD. Consensus has yet to develop for the management of steroid-refractory acute GVHD, and prognosis at six months has been estimated at around 50%. Thus, it is critical to find effective treatments that increase survival of steroid-refractory acute GVHD. This article describes the currently known characteristics, pathophysiology, and treatments for GVHD, with a special focus on recent advances in cell therapies. In particular, a novel cell therapy using decidua stromal cells (DSCs) was recently shown to have promising results for acute GVHD, with improved effectiveness over previous treatments including mesenchymal stromal cells. At the Karolinska Institute, severe acute GVHD patients treated with placenta-derived DSCs supplemented with either 5% albumin or 10% AB plasma displayed a one-year survival rate of 76% and 47% respectively. Furthermore, patients with steroid-refractory acute GVHD, displayed survival rates of 73% with albumin and 31% with AB plasma-supplemented DSCs, compared to the 20% survival rate in the mesenchymal stromal cell control group. Adverse events and deaths were found to be attributed only to complications of hematopoietic stem cell transplant and GVHD, not to the study intervention. ASC Therapeutics, Inc, in collaboration with the Karolinska Institute, will soon initiate a phase 2 multicenter, open-label study to further assess the efficacy and safety of intravenous DSC treatment in sixty patients with Grade II-IV steroid-refractory acute GVHD. This novel cell therapy represents a promising treatment to combat the poor prognosis that steroid-refractory acute GVHD patients currently face.

Prognostic Biomarkers for Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome in Myeloablative Allogeneic Hematopoietic Cell Transplantation: Results from the Blood and Marrow Transplant Clinical Trials Network 1202 Study

Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation (HCT). This study aimed to determine a blood biomarker signature early post-HCT that identifies patients at high risk for VOD/SOS. A set of 23 plasma biomarkers, selected from the VOD/SOS literature, was measured on days 0, 7, and 14 after myeloablative HCT using blood samples from patients enrolled in the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Protocol 1202. Eligible cases were diagnosed with VOD/SOS in BMT CTN 1202 using the Baltimore criteria. Controls (without VOD/SOS) were matched to cases for conditioning regimen and age. Significant biomarkers were identified using the Bonferroni-adjusted Wilcoxon rank-sum test (P ≤ .002). Thirty-three patients with mild or severe VOD/SOS were identified (cases) and matched to 107 controls. Two, 8, and 5 biomarkers measured from the plasma of these patients were significantly associated with the development of VOD/SOS at days 0, 7, and 14, respectively, with the strongest associations on days 7 and 14. Biomarker associations were stronger for severe VOD/SOS risk and were stronger prognostic markers for VOD/SOS cases occurring within 28 days of HCT. Hyaluronan was most strongly associated with VOD/SOS risk, with an area under the receiver operating characteristic curve (AUC) of .81 on day 7 and .79 on day 14. Multivariate models of up to 5 biomarkers generated AUCs ranging from .82 to .85. All associations with VOD/SOS risk were independent of clinical risk factors. This study confirms previously identified biomarkers of VOD/SOS risk and identified novel prognostic biomarker signatures that identify patients at risk for VOD/SOS shortly after HCT. Multivariate analysis suggests that a combination of up to 5 of these protein biomarkers may provide a prognostic tool for identifying patients at risk for VOD/SOS.

Minor histocompatibility antigens HA-8 and PANE1 in the TUNISIAN population

BACKGROUND

Minor histocompatibility antigens (mHAgs) are endogenous immunogenic peptides initially identified due to complications detected in several contexts of HLA geno-identical hematopoietic stem cell transplantation (HSCT). In this study, we chose to examine the molecular polymorphism of the mHAgs HA-8 and PANE1 in the Tunisian population.

MATERIAL AND METHODS

This study was conducted on 150 healthy and unrelated individuals. The DNA extraction and Sequence-Specific Primers PCR (PCR-SSP) methods were used for the molecular genotyping of the selected SNPs: PUM3 (rs2173904) and CENPM (rs5758511).

RESULTS

Our results show that, 94% of Tunisians are carriers of the PANE1R allele (immunogenic variant of the PANE1 mHAg) and 68% of Tunisians are carriers of the HA-8R allele (immunogenic variant of the HA-8 mHAg). Furthermore, this study shows that about 5% of the Tunisians are carrier of the PANE1R antigen and its HLA molecule of presentation (the PANE1R/HLA-A*0301 combination). However, only 2% of Tunisians are carrier of the HA-8R/HLA-A*0201 combination, that is, the HA8 immunogenic variant and its specific HLA molecule of presentation.

CONCLUSION

Our results are close to those reported in Caucasian, Asiatic, and African populations, this may be explained by the historical events experienced by Tunisia for millennia. These results could be used for further clinical and anthropological studies.

Herpesvirus Screening in Childhood Hematopoietic Transplant Reveals High Systemic Inflammation in Episodes of Multiple Viral Detection and an EBV Association with Elevated IL-1β, IL-8 and Graft-Versus-Host Disease

Infections remain a major cause of morbidity and mortality among hematopoietic stem cell transplant (HSCT) recipients. Unlike Epstein–Barr Virus (EBV) and Human Cytomegalovirus (HCMV), Human Herpesvirus (HHV) 6, HHV7 and HHV8 are not routinely monitored in many centers, especially in the pediatric population of low–medium income countries. We screened EBV, HCMV, HHV6, HHV7 and HHV8 in 412 leukocytes-plasma paired samples from 40 pediatric patients assisted in a tertiary hospital in Mexico. Thirty-two underwent allo-HSCT, whereas eight received auto-HSCT. Overall viral detection frequencies in allo- and auto-HSCT were: EBV = 43.7% and 30.0%, HCMV = 5.0% and 6.7%, HHV6 = 7.9% and 20.0% and HHV7 = 9.7% and 23.3%. HHV8 was not detected in any sample. Interestingly, HHV6 and HHV7 were more frequent in auto-HSCT, and HHV6 was observed in all episodes of multiple detection in auto-HSCT patients. We found EBV DNA in plasma samples, whereas HCMV, HHV6 and HHV7 DNA were predominantly observed in leukocytes, indicative of their expansion in cellular compartments. We also found that IL-1β, IL-2, IL-6 and IL-8 were significantly increased in episodes in which multiple viruses were simultaneously detected, and samples positive for EBV DNA and graft-versus-host disease had a further increase of IL-1β and IL-8. In conclusion, the EBV, HCMV, HHV6 and HHV7 burdens were frequently detected in allo- and auto-HSCT, and their presence associated with systemic inflammation.