Biomarkers in chronic graft-versus-host disease: quo vadis?

Biomarkers are increasingly used for diagnosis and treatment of transplant-related complications including the first biomarker-driven interventional trials of acute graft-versus-host disease (GvHD). In contrast, the development of biomarkers of chronic GvHD (cGvHD) has lagged behind due to a broader variety of manifestations, overlap with acute GvHD, a greater variation in time to onset and maximum severity, and lack of sufficient patient numbers within prospective trials. An international workshop organized by a North-American and European consortium was held in Marseille in March 2017 with the goal to discuss strategies for future biomarker development to guide cGvHD therapy. As a result of this meeting, two areas were prioritized: the development of prognostic biomarkers for subsequent onset of moderate/severe cGvHD, and in parallel, the development of qualified clinical-grade assays for biomarker quantification. The most promising prognostic serum biomarkers are CXCL9, ST2, matrix metalloproteinase-3, osteopontin, CXCL10, CXCL11, and CD163. Urine-proteomics and cellular subsets (CD4+ T-cell subsets, NK cell subsets, and CD19+CD21low B cells) represent additional potential prognostic biomarkers of cGvHD. A joint effort is required to verify the results of numerous exploratory trials before any of the potential candidates is ready for validation and subsequent clinical application.

Novel targets in the treatment of chronic graft-versus-host disease.

Despite advances that have improved survival after allogeneic hematopoietic stem cell transplantation (HCT), chronic graft-versus-host disease (GVHD) remains a leading cause of late morbidity and mortality after transplant. Current treatment options show limited efficacy in steroid-refractory disease, and there exists a paucity of robust data to guide management decisions. Lack of United States Food and Drug Administration (FDA)- or European Medicines Agency (EMA)-approved agents in GVHD underscore the importance of developing novel therapies. Better understanding of the biology of chronic GVHD has provided novel targets for treatment, and structured guidelines in diagnosis and in clinical trial design have provided a common language and pathways for research in this area. These, combined with the surge of drug development in Oncology and Immunology, are factors that have contributed to the accelerating field of drug development and clinical research in chronic GVHD. In these exciting times, it is possible to foresee long awaited advances in the treatment of this devastating complication of HCT. This review will summarize the ongoing clinical development for novel therapies in chronic GVHD.

Development, preliminary usability and accuracy testing of the EBMT 'eGVHD App' to support GvHD assessment according to NIH criteria-a proof of concept.

The EBMT Complications and Quality of Life Working Party has developed a computer-based algorithm, the 'eGVHD App', using a user-centered design process. Accuracy was tested using a quasi-experimental crossover design with four expert-reviewed case vignettes in a convenience sample of 28 clinical professionals. Perceived usefulness was evaluated by the technology acceptance model (TAM) and User satisfaction by the Post-Study System Usability Questionnaire (PSSUQ). User experience was positive, with a median of 6 TAM points (interquartile range: 1) and beneficial median total, and subscale PSSUQ scores. The initial standard practice assessment of the vignettes yielded 65% correct results for diagnosis and 45% for scoring. The 'eGVHD App' significantly increased diagnostic and scoring accuracy to 93% (+28%) and 88% (+43%), respectively (both P<0.05). The same trend was observed in the repeated analysis of case 2: accuracy improved by using the App (+31% for diagnosis and +39% for scoring), whereas performance tended to decrease once the App was taken away. The 'eGVHD App' could dramatically improve the quality of care and research as it increased the performance of the whole user group by about 30% at the first assessment and showed a trend for improvement of individual performance on repeated case evaluation.

Prevalence and determinants of fatigue in patients with moderate to severe chronic GvHD.

Although fatigue is common after allogeneic hematopoietic cell transplantation, little is known about fatigue in patients with chronic GvHD (cGvHD). The aim of this study was to explore factors associated with fatigue in cGvHD. Data were drawn from a sequentially recruited, cross-sectional study of adults with moderate or severe cGvHD (n=263). Respondents were classified as fatigued or not fatigued based on their response to a single item regarding loss of energy from the Lee cGvHD Symptom Scale. In univariate analysis, factors significantly associated with fatigue included performance status, number of prior cGvHD therapies, cGvHD symptom bother, self-assessed physical and mental health, nutritional status, walk velocity and self-reported physical activity. There were no significant associations between fatigue and disease-related cGvHD variables. Multivariable logistic regression demonstrated that being less active and having pulmonary and/or muscle/joint symptoms were independently associated with fatigue. In conclusion, clinically significant fatigue was prevalent in more than one-third of subjects with cGvHD, and was disabling. Absence of association with measures of cGvHD severity underscores the need to elucidate the pathogenesis of fatigue and its relationship with inflammatory activity. Pulmonary and muscle/joint symptoms and physical inactivity represent potential targets for intervention in clinical studies.

Oral disease profiles in chronic graft versus host disease.

At least half of patients with chronic graft-versus-host-disease (cGVHD), the leading cause of morbidity and non-relapse mortality after allogeneic stem cell transplantation, have oral manifestations: mucosal lesions, salivary dysfunction, and limited mouth-opening. cGVHD may manifest in a single organ or affect multiple organ systems, including the mouth, eyes, and the skin. The interrelationship of the 3 oral manifestations of cGVHD with each other and with the specific manifestations of extraoral cGVHD has not been studied. In this analysis, we explored, in a large group of patients with cGVHD, the potential associations between: (1) oral mucosal disease and erythematous skin disease, (2) salivary gland dysfunction and lacrimal gland dysfunction, and (3) limited mouth-opening and sclerotic skin cGVHD. Study participants, enrolled in a cGVHD Natural History Protocol (NCT00331968, n = 212), underwent an oral examination evaluating: (1) mucosal cGVHD [NIH Oral Mucosal Score (OMS)], (2) salivary dysfunction (saliva flow and xerostomia), and (3) maximum mouth-opening measurement. Parameters for dysfunction (OMS > 2, saliva flow ≤ 1 mL/5 min, mouth-opening ≤ 35 mm) were analyzed for association with skin cGVHD involvement (erythema and sclerosis, skin symptoms), lacrimal dysfunction (Schirmer's tear test, xerophthalmia), Lee cGVHD Symptom Scores, and NIH organ scores. Oral mucosal disease (31% prevalence) was associated with skin erythema (P < 0.001); salivary dysfunction (11% prevalence) was associated with lacrimal dysfunction (P = 0.010) and xerostomia with xerophthalmia (r = 0.32, P = 0.001); and limited mouth-opening (17% prevalence) was associated with skin sclerosis (P = 0.008) and skin symptoms (P = 0.001). There was no association found among these 3 oral cGVHD manifestations. This analysis supports the understanding of oral cGVHD as 3 distinct diseases: mucosal lesions, salivary gland dysfunction, and mouth sclerosis. Clear classification of oral cGVHD as 3 separate manifestations will improve clinical diagnosis, observational research data collection, and the definitions of outcome measures in clinical trials.

NIH response criteria measures are associated with important parameters of disease severity in patients with chronic GVHD.

Lack of standardized criteria measuring therapeutic response remains an obstacle to the development of better treatments for chronic GVHD (cGVHD). This cross-sectional prospective study examined the concurrent and predictive validity of 18 clinician-reported ('Form A') and 8 patient-reported ('Form B') response measures proposed by NIH criteria. Concurrent parameters of interest were NIH global score, cGVHD activity, Lee symptom score and SF36 PCS. Patient cohort included 193 adults with moderate-to-severe cGVHD. Measures associated with the highest number of outcomes were lung function score (LFS), 2-min walk, grip strength, 4-point health-care provider (HCP) and patient global scores, 11-point clinician- and patient-reported global symptom severity scores, and Karnofsky performance score (KPS). Measures associated with survival in univariate analyses led to a Cox model containing skin erythema, LFS, KPS, eosinophil count and interval from cGVHD diagnosis to enrollment as jointly associated with survival. In conclusion, 4-point HCP and patient global scores and 11-point clinician- and patient-reported global symptom severity scores are associated with the majority of concurrent outcomes. Skin erythema is a potentially reversible sign of cGVHD that is associated with survival. These results define a subset of measures that should be prioritized for evaluation in future studies.

Malnutrition in patients with chronic GVHD.

Malnutrition is a known complication of chronic GVHD (cGVHD), but has not been well described in the context of organ-specific manifestations and the recent National Institutes of Health (NIH) criteria. Here, 210 cGVHD patients were analyzed, in a cross-sectional study design, for demographics, transplant-related history, clinical assessments, symptoms, function, quality-of-life, laboratory values and survival in order to determine their associations with nutritional status. Most patients had long-standing, moderate or severe cGVHD and had failed many lines of therapy. Twenty-nine percent (60/210) of subjects were malnourished, using the subjective Patient-Generated Subjective Global Assessment (PG-SGA) questionnaire and evaluation. No demographic or transplant characteristics were associated with malnutrition; cGVHD of the lungs, gastrointestinal (GI) tract and mouth, NIH global score, cGVHD symptoms, worse functioning, low albumin, poorer survival and low BMI were associated with malnutrition. A predictive model was developed from all variables of significance: cGVHD of the lungs, GI tract, mouth and BMI accurately predicted 84.2% of malnourished patients as well as 87.2% of well-nourished patients. The PG-SGA questionnaire may be a useful tool in diagnosing nutritional deficits in cGVHD patients undergoing one-time evaluations. Longitudinal prospective studies should assess the utility of nutritional support interventions in cGVHD.

Health-related quality of life in pediatric patients after allogeneic SCT: development of the PedsQL Stem Cell Transplant module and results of a pilot study.

With increased survival after pediatric allogeneic hematopoietic SCT health-related quality of life (HRQL) has emerged as an essential health outcome. The impact of transplant and chronic GVHD (cGVHD)-associated morbidity remains a major obstacle. In 2005, the National Institutes of Health (NIH) Consensus Conference on Criteria for Clinical Trials in cGVHD recommended HRQL tools as an independent measure of the impact of disease burden. The NIH recommendations did not provide a cGVHD-specific tool for HRQOL measures in children. This report focuses on the development of an SCT-specific instrument to assess HRQL in children and adolescents. For the assessment of generic HRQL we chose the PedsQL (Pediatric Quality of Life Inventory) Generic Cores Scales, which have been used in a large number of healthy, acutely ill and chronically ill children and adolescents. To capture SCT- and, specifically, cGVHD-related problems, we developed the PedsQL Stem Cell Transplant module by reviewing the literature, taking over some items/scales of other PedsQL modules, interviewing patients, parents and members of the health-care team, and applying the PedsQL measurement methods. The final PedsQL Stem Cell Transplant module consists of the HRQL domains: pain and hurt, fatigue/sleeping problems/weakness, nausea, worry/anxiety about disease/treatment, nutritional problems, neurocognitive problems, communication about disease/treatment, loneliness, physical functioning and additional somatic complaints (pruritus, skin inflammation, oral problems, eyes or breathing) including patients' and parents' assessment. It was tested in 35 pediatric patients, who were referred to our SCT Outpatient Clinic about 100 days post SCT. Both the generic PedsQL and the SCT-specific scales showed high internal consistency, with Cronbach alpha levels of ⩾0.70 in almost all scales. Most problems were detected within the HRQL domains of physical functioning and pain. The summary scores of the generic PedsQL and the PedsQL Stem Cell Transplant module showed high correlations (r=0.89 in patients' and r=0.81 in parents' assessments). Moreover, both tools discriminated between patients with and without cGVHD. The PedsQL Stem Cell Transplant module is practical for use and suitable across a broad age range (2-18 years) both in patients with and without cGVHD. However, it is still a pilot instrument and needs further development and testing in a larger patient population.

Comparative analysis of FoxP3(+) regulatory T cells in the target tissues and blood in chronic graft versus host disease.

Activation and migration of regulatory T cells (Treg) into tissue is critical in control of inflammation, but has not been examined extensively in chronic graft versus host disease (cGVHD). In parallel studies of tissues and blood, we determined that FoxP3(+) T cells increased in proportion to T effectors (Teff) in tissue infiltrates in oral and cutaneous lichenoid cGVHD. These FoxP3(+) cells expressed distinguishing phenotypic and functional markers of Treg (CD3(+), CD4(+), CD27(+), ICOS(+) and CD39(+)), not found on FoxP3(-) Teff. Both Teff and FoxP3(+) Treg expressed T-bet and the chemokine receptor CXCR3, however, consistent with a common mechanism of chemokine-mediated migration into tissue. Furthermore, functional markers (ICOS and CD39) and chemokine receptors (CXCR3) were both present in a higher proportion of FoxP3(+) cells in tissues than in peripheral blood, consistent with recruitment and activation of Treg in cGVHD target tissues. Finally, the 'activated' CD45RA(-)FoxP3(hi) subset of Treg cells, which highly express functional markers, were found in comparable frequencies in cGVHD patients and normal controls, despite a significant deficit in naive 'resting' Treg. These findings are consistent with Treg capacity to upregulate functional markers and traffick into tissue in cGVHD.

Investigator feedback about the 2005 NIH diagnostic and scoring criteria for chronic GVHD.

The 2005 National Institutes of Health (NIH) consensus criteria for chronic GVHD have set standards for reporting. Many questions, however, have arisen regarding their implementation and utilization. To identify perceived areas of controversy, we conducted an international survey on diagnosis and scoring of chronic GVHD. Agreement was observed for 50-83% of the 72 questions in 7 topic areas. There was agreement on the need for modifying criteria in six situations: two or more distinctive manifestations should be enough to diagnose chronic GVHD; symptoms that are not due to chronic GVHD should be scored differently; active disease and fixed deficits should be distinguished; a minimum threshold body surface area of hidebound skin involvement should be required for a skin score of 3; asymptomatic oral lichenoid changes should be considered a score 1; and lung biopsy should be unnecessary to diagnose chronic GVHD in a patient with bronchiolitis obliterans as the only manifestation. The survey also identified 26 points of controversy. Whenever possible, studies should be conducted to confirm the appropriateness of any revisions. In cases where data are not available, clarification of the NIH recommendations by consensus is necessary. This survey should inform future research in the field and revisions of the current consensus criteria.

NHANES III equations enhance early detection and mortality prediction of bronchiolitis obliterans syndrome after hematopoietic SCT.

Bronchiolitis obliterans syndrome (BOS) is a serious complication of chronic GVHD (cGVHD) following HSCT (hematopoietic SCT). The clinical diagnosis of BOS is based on pulmonary function test (PFT) abnormalities including: FEV1<75% predicted and obstructive FEV1/VC ratio, calculated using reference equations. We sought to determine if the frequency of clinical diagnoses and severity of BOS would be altered by using the recommended NHANES III vs older equations (Morris/Goldman/Bates, MGB) in 166 cGVHD patients, median age 48 (range: 12-67). We found that NHANES III equations significantly increased the prevalence of BOS, with an additional 11% (18/166) meeting diagnostic criteria by revealing low FEV1 (<75%) (P<0.0001), and six additional patients by obstructive ratio (vs MBG). Collectively, this led to an increase of BOS incidence from 17 (29/166) to 29% (41/166). For patients with severe BOS, (FEV1<35%), NHANES III equations correctly predicted death 71.4% vs 50% using MGB. In conclusion, the use of NHANES III equations markedly increases the proportion of cases meeting diagnostic criteria for BOS and improves prediction of survival.

Validation of the National Institutes of Health chronic GVHD Oral Mucosal Score using component-specific measures.

Oral chronic GVHD (cGVHD) is a common, late complication of alloSCT that is associated with significant patient morbidity. The NIH Oral Mucosal Score (NIH OMS) was developed to assess oral cGVHD therapeutic response, but has not been fully validated. This study's purpose was to conduct a rigorous construct validity and internal consistency analysis of this score and its components (erythema, lichenoid, ulcers, mucoceles) using established measures of oral pain, oral function, oral-related quality-of-life, nutrition and laboratory parameters in 198 patients with cGVHD. The construct validity of the NIH OMS was supported: a moderate correlation was observed between NIH OMS and mouth pain (rho=0.43), while a weaker correlation was observed with low albumin (rho=-0.26). Total NIH OMS, erythema and lichenoid components were associated with malnutrition, oral pain and impaired oral QOL, while ulcers were only associated with oral pain. No associations were found between mucoceles and any indicator evaluated, including salivary function or xerostomia. Kappa determined between scale components was low overall (all 0.35), supporting a conclusion that each component measures a distinct manifestation of oral cGVHD. This study supports the use of the NIH OMS and its components (erythema, lichenoid and ulcerations) to measure clinician-reported severity of oral cGVHD.

Uptake and use of recommendations for the diagnosis, severity scoring and management of chronic GVHD: an international survey of the EBMT-NCI Chronic GVHD Task Force.

In 2005, the National Institutes of Health (NIH) consensus conference published a series of papers recommending methods to improve the conduct of clinical trials in chronic GVHD. Although the NIH recommendations were primarily aimed at strengthening research, several papers addressed issues relevant for clinical practice, particularly diagnosis, severity scoring, and ancillary and supportive care practices. We conducted an international survey to assess the uptake of these recommendations, identify barriers to greater use and document the use and perceived effectiveness of available treatments. The response rate for the American survey of 1387 practitioners was 21.8%, and it was 24.6% for 407 centers surveyed in Europe, Asia, Australia and Africa. Most respondents were familiar with the NIH consensus recommendations (94-96%) and used them in practice. Multiple barriers to greater use were reported. Besides lack of time (55-62%), unfamiliarity with the recommendations, scarcity of evidence supporting the impact of recommendations on outcomes, insufficient training/experience in chronic GVHD management and inaccessibility of subspecialists were also endorsed. Systemic corticosteroids were reported to be the most effective treatment for chronic GVHD, but many others were perceived to have moderate or great success. Therapeutic management of steroid-refractory chronic GVHD was identified as the highest priority for research.

Active thrombopoiesis is associated with worse severity and activity of chronic GVHD.

Chronic GVHD (cGVHD) is a major complication of allogeneic hematopoietic SCT. Post transplant thrombocytopenia in patients with cGVHD has been associated with poor outcome and its etiology is unclear. We investigated whether thrombopoiesis, assessed via measurement of the absolute immature platelet number (AIPN) in the blood, is impaired in cGVHD, and whether the level of thrombopoiesis correlates with the severity and activity of cGVHD as assessed via the National Institutes of Health (NIH) organ scoring system. We used a cohort of 110 well-characterized cGVHD patients, including 83 (75%) with severe cGVHD per NIH global score. Higher AIPN was associated with active therapeutic intent (P=0.026), lower Karnofsky score (P=0.0013), worse joint/fascia cGVHD (P=0.0005) and worse skin cGVHD (P=0.0044). AIPN correlated with platelet counts and was not correlated with ANC, WBC, C-reactive protein (CRP), absolute lymphocyte count (ALC), albumin, total and average NIH scores, or number of prior systemic therapies. AIPN values for cGVHD patients substantially overlapped those of the normal population. Higher AIPN, as marker of active thrombopoiesisis, was associated with worse severity and activity of cGVHD, especially skin and joints/fascia manifestations. Among patients with stable moderate or severe cGVHD, there was no evidence of hypoproduction of platelets. Future studies should further investigate the role of thrombopoiesis in cGVHD.

Comorbidity burden in patients with chronic GVHD.

Chronic GVHD (cGVHD) is associated with mortality, disability and impaired quality of life. Understanding the role of comorbidity in patients with cGVHD is important both for prognostication and potentially for tailoring treatments based on mortality risks. In a prospective cohort study of patients with cGVHD (n=239), we examined the performance of two comorbidity scales, the Functional Comorbidity Index (FCI) and the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI). Both scales detected a higher number of comorbidities at cGVHD cohort enrollment than pre-hematopoietic cell transplant (HCT) (P<0.001). Higher HCT-CI scores at the time of cGVHD cohort enrollment were associated with higher non-relapse mortality (HR: 1.21:1.04-1.42, P=0.01). For overall mortality, we detected an interaction with platelet count. Higher HCT-CI scores at enrollment were associated with an increased risk of overall mortality when the platelet count was ≤ 100,000/µL (HR: 2.01:1.20-3.35, P=0.01), but not when it was >100,000/µL (HR: 1.05:0.90-1.22, P=0.53). Comorbidity scoring may help better to predict survival outcomes in patients with cGVHD. Further studies to understand vulnerability unrelated to cGVHD activity in this patient population are needed.

Measurement of oral chronic GVHD: results from the Chronic GVHD Consortium.

Oral chronic GVHD (cGVHD) is a serious complication of alloSCT. Scales and instruments to measure oral cGVHD activity and severity have not been prospectively validated. The objective of this study was to describe the characteristics of oral cGVHD and determine the measures most sensitive to change. Patients enrolled in the cGVHD Consortium with oral involvement were included. Clinicians scored oral changes according to the National Institutes of Health (NIH) criteria, and patients completed symptom and quality-of-life measures at each visit. Both rated change on an eight-point scale. Of the 458 participants, 72% (n=331) had objective oral involvement at enrollment. Lichenoid change was the most common feature (n=293; 89%). At visits where oral change could be assessed, 50% of clinicians and 56% of patients reported improvement, with worsening reported in 4-5% for both the groups (weighted kappa=0.41). Multivariable regression modeling suggested that the measurement changes most predictive of perceived change by clinicians and patients were erythema and lichenoid, NIH severity and symptom scores. Oral cGVHD is common and associated with a range of signs and symptoms. Measurement of erythema and lichenoid changes and symptoms may adequately capture the activity of oral cGVHD in clinical trials but require prospective validation.

Chronic GVHD: Where are we? Where do we want to be? Will immunomodulatory drugs help?

Chronic GVHD (cGVHD) is an important problem after allotransplants. Some risk factors for cGVHD are similar to those of acute GVHD (aGVHD) but others are distinct indicating sometimes overlapping but unique pathogeneses. Precise incidence and prevalence data of cGVHD are lacking because of diverse diagnostic criteria but a 50% risk is a reasonable estimate. Incidence and prevalence of cGVHD are probably growing because of increased use of unrelated donors, blood rather than bone marrow (BM) grafts, decreased early transplant-related mortality (TRM) and increasing frequency of allotransplants. Pathophysiology of cGVHD is complex and poorly understood. Notably, no reliable surrogate end point to predict mechanism(s) of cGVHD has been identified. Therapy of cGVHD is unsatisfactory. Corticosteroids are effective but other drugs are controversial and few are rigorously tested in randomized trials. Highly variable response rates are reported because of small sample sizes and inconsistencies in eligibility, diagnostic and response criteria. We focus on the possible role of immunomodulatory drugs (IMiDs), thalidomide lenalidomide and pomalidomide, in preventing and treating cGVHD. The data suggest activity of thalidomide but at doses not clinically practical in many instances. There are few data with lenalidomide. Trials of pomalidomide, which has immune activities like thalidomide but with fewer adverse effects, are beginning. Because cGVHD is not recently reviewed in Bone Marrow Transplantation, we give a brief background and discuss challenges in diagnosing, understanding and treating cGVHD including the recently proposed National Institutes of Health consensus criteria for cGVHD.