Acute graft-vs-host disease: pathobiology and management

Case report: Toxic epidermal necrolysis as a unique presentation of acute graft versus host disease in a pediatric patient

Introduction

Acute graft versus host disease (aGVHD) is a common complication of stem cell transplant (SCT), with skin involvement being most common. Severe presentations of skin aGVHD involving rapid progression of rash to bullae formation and mucosal involvement are rare. There are reports of patients with skin aGVHD that present with clinical characteristics mimicking toxic epidermal necrolysis (TEN), suggesting a possible overlap between the two. Management and outcomes of pediatric patients with this overlapping, severe presentation have rarely been described.

Case presentation

This report describes an 11-year-old boy with refractory T-cell acute lymphoblastic leukemia who received peripheral blood SCT from a matched unrelated donor. Day 26 post-SCT, he developed a maculopapular facial rash, which progressed to the development of vesicles coalescing into bullae involving his conjunctiva, face, oral mucosa, and genital mucosa. Initially, systemic steroid monotherapy was initiated, but with rapid rash progression and mucosal involvement, intravenous immunoglobulin (IVIg) 2 g/kg divided over 5 days was added as management for suspected TEN-like aGVHD based on clinical findings. Ruxolitinib was subsequently started as adjunctive management for aGVHD. His skin findings continued to improve with near total resolution by day 49 post-SCT.

Conclusion

We report a unique case of TEN-like aGVHD with rapid progression to >30% body surface area involvement including bullae formation and detachment of epidermis. There have been few case reports of similar presentations, most with poor outcomes. We aim to supplement the literature available by reporting our successful management with steroids, IVIg, and ruxolitinib, which resulted in early resolution of symptoms in a pediatric patient.

Evaluation of the Clinical Outcomes of Cyclosporine Short Infusion Versus Continuous Infusion Postallogenic Stem Cell Transplantation

BACKGROUND AND OBJECTIVE

Cyclosporin A (CsA) exhibits a narrow therapeutic index and large inter-individual variation in pharmacokinetics. Two intermittent and 24-h continuous infusions (CI) are both commonly used regimens in hematopoietic stem cell transplantation (HSCT), with no universal consensus. The objective of this study was to assess whether CsA as a 2-h, twice-daily intravenous infusion (2 h/12 h) is non-inferior to 22 h CI every 24 h (22 h-CI/24 h) in terms of acute graft-versus-host disease (aGVHD) incidence and adverse events in allogeneic HSCT adult patients.

METHODS

An open-label randomized trial recruited 31 allogeneic HSCT patients to receive the 2 h/12 h or 22 h-CI/24 h regimen. The primary outcomes were the incidence of aGVHD and CsA-related adverse events. The secondary outcomes included the correlation between the time concentration and area under the concentration-time curve (AUC) of 2 h/12 h versus 22 h-CI/24 h regimens.

RESULTS

Six (19.4%) patients developed aGVHD. There was no statistically significant difference between the two groups concerning the incidence of aGVHD (13.3% in 2 h/12 h vs. 25% in 22 h-CI/24 h; p = 0.359). The distribution of different aGVHD types (p = 0.20) and mortality (p = 0.9) were not significantly different between the two groups. The two groups did not differ at any time with respect to AUCs, nephrotoxicity, hepatotoxicity, or electrolyte disturbance.

CONCLUSION

The study suggested that the 2 h/12 h regimen is non-inferior to the conventional regimen (22 h CI/24 h) in terms of aGVHD incidence and adverse events. Further research is necessary to validate these findings and to guide practice, considering the small sample size of this study.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT04575779 with initial release on 19 September 2020-Retrospectively registered, https://clinicaltrials.gov/study/NCT04575779 .

Vaginal complications of graft-versus-host disease after hematopoietic stem cell transplantation: a cross-sectional study

Background

Stem cell transplantation is a clinical approach used to treat certain types of cancers, such as hematologic malignancies. Graft-versus-host disease (GVHD) occurs in 30-70% of cases and often diminishes the quality of life of transplant patients. This study aimed to determine the prevalence of vaginal complications of GVHD following hematopoietic stem cell transplantation.

Methods

This study employed an analytical cross-sectional design. All patients referred to Shariati Hospital in Tehran between 2019 and 2020 who underwent hematopoietic stem cell transplantation were considered for inclusion in this study if they met the inclusion criteria. Inclusion criteria encompassed nonnot sexually active women aged 18-70 who received stem cell transplantation more than 100 days prior. Exclusion criteria comprised patients who experienced GVHD during the first 100 days posttransplantation. Additionally, individuals over 75 and patients with metastatic cancer were excluded.

Results

A total of 55 patients were recruited, with ages averaging 40±9.9 years for recipients and 38.5±12.8 years for donors. Notably, 63.3 and 58.2% of patients exhibited oral and ocular symptoms, respectively. Regarding genital involvement, 49.1% experienced vaginal symptoms, while 25.5% had vulvar involvement. Among the 27 patients with vaginal involvement, two (7.4%) were categorized as mild, 17 (63%) as moderate, and eight (29.6%) as severe. Univariate analysis identified reduced vaginal discharge [odds ratio (OR=6.56)], vaginal tightness (OR=6.23), pelvic pain (OR=5.50), and vaginal involvement (OR=3.81) as significant predictors of other organ symptoms. Moreover, vaginal involvement (OR=3.68) emerged as the sole significant predictor of the cooccurrence of oral, ocular, and other organ symptoms. In the multivariate analysis, reduced vaginal discharge (OR=8.24) and vaginal tightness (OR=3.92) significantly predicted other organ symptoms (P=0.009).

Conclusion

Reduced vaginal discharge and vaginal tightness remained significant predictors of other organ symptoms.

Imaging findings of breast leukaemia: a case series

Aims/Background Breast leukaemia (BL) is a rare breast malignancy that is treated differently from other malignant conditions. However, it is easily confused with other conditions; therefore, how to accurately diagnose is crucial. We retrospectively analysed the imaging findings of 13 patients to provide a diagnostic reference. Methods From January 2015 to April 2023, 13 patients with BL confirmed by biopsy who underwent imaging in Peking University People's hospital were retrospectively analysed. The imaging findings obtained via ultrasound (US), mammography (MMG), magnetic resonance imaging (MRI), and positron emission tomography/computed tomography (PET/CT) were analysed, and the detection rates of these methods for diagnosing BL were compared. Results Twenty-nine lesions were detected in the 13 patients. These patients presented with palpable masses or breast swelling several months after treatment for leukaemia, mainly involving the bilateral breasts. Ultrasonography was performed for 13 patients, and all lesions were detected. Most of the identified masses were hypoechoic and had indistinct boundaries, irregular shapes, no enhancement of the posterior echo, and no abundant blood flow. MMG was performed for five patients, revealing breast masses, architectural distortion, and no abnormalities. MRI was performed for four patients, and all lesions were detected; most of the lesions were hypointense on T1-weighted imaging and hyperintense on T2-weighted imaging and diffusion-weighted imaging, with a decreased apparent diffusion coefficient and inhomogeneous enhancement. The enhancement curves were mostly inflow patterns. PET/CT was performed for four patients; two patients had hypermetabolism, and the other two had no obvious radioactive uptake. Conclusion Compared to MMG and PET/CT, US and MRI have higher detection rates. Furthermore, compared to MRI, US is inexpensive, convenient and efficient; therefore, it should be the first choice for diagnosing BL.

Exopolysaccharide-Treated Dendritic Cells Effectively Ameliorate Acute Graft-versus-Host Disease

Graft-versus-host disease (GVHD) is a primary and often lethal complication of allogenic hematopoietic stem cell transplantation (HSCT). Prophylactic regimens for GVHD are given as standard pretransplantation therapy; however, up to 50% of these patients develop acute GVHD (aGVHD) and require additional immunosuppressive intervention. Using a mouse GVHD model, we previously showed that injecting mice with exopolysaccharide (EPS) from Bacillus subtilis prior to GVHD induction significantly increased 80-day survival after transplantation of complete allogeneic major histocompatibility complex-mismatched cells. To ask whether EPS might also inhibit GVHD in humans, we used humanized NSG-HLA-A2 mice and induced GVHD by i.v. injection of A2neg human peripheral blood mononuclear cells (PBMCs). Because we could not inject human donors with EPS, we transferred EPS-pretreated dendritic cells (DCs) to inhibit aGVHD. We derived these DCs from CD34+ human cord blood cells, treated them with EPS, and then injected them together with PBMCs into the NSG-HLA-A2 mice. We found that all mice that received untreated DCs were dead by day 35, whereas 25% of mice receiving EPS-treated DCs (EPS-DCs) survived. This DC cell therapy could be readily translatable to humans, because we can generate large numbers of human EPS-DCs and use them as an "off the shelf" treatment for patients undergoing HSCT.

Basiliximab Treatment for Patients With Steroid-Refractory Acute Graft-Versus-Host Disease Following Matched Sibling Donor Hematopoietic Stem Cell Transplantation

Basiliximab is an important treatment for steroid-refractory acute graft-versus-host disease (SR-aGVHD). We performed this retrospective study to evaluate the efficacy and safety of basiliximab treatment in SR-aGVHD patients following matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) (n = 63). Overall response rate (ORR) was 63.5% and 54% at any time and at day 28 after basiliximab treatment. Grade III-IV aGVHD before basiliximab treatment predicted a poor ORR after basiliximab treatment. The rates of virus, bacteria, and fungi infections were 54%, 23.8%, and 3.1%, respectively. With a median follow-up of 730 (range, 67-3,042) days, the 1-year probability of overall survival and disease-free survival after basiliximab treatment were 58.6% (95% confidence interval [CI] = 47.6%-72.2%) and 55.4% (95% CI = 44.3%-69.2%), respectively. The 3-year cumulative incidence of relapse and non-relapse mortality after basiliximab treatment were 18.9% (95% CI = 8.3%-29.5%) and 33.8% (95% CI = 21.8%-45.7%), respectively. Comorbidities burden before allo-HSCT, severity of aGVHD and liver aGVHD before basiliximab treatment showed negative influences on survival. Thus, basiliximab was safe and effective treatment for SR-aGVHD following MSD-HSCT.

Defining a TCF1-expressing progenitor allogeneic CD8+ T cell subset in acute graft-versus-host disease

Graft-versus-host disease (GvHD) is a severe complication of hematopoietic stem cell transplantation driven by activated allogeneic T cells. Here, we identify a distinct subset of T cell factor-1 (TCF1)+ CD8+ T cells in mouse allogeneic and xenogeneic transplant models of acute GvHD. These TCF1+ cells exhibit distinct characteristics compared to TCF1- cells, including lower expression of inhibitory receptors and higher expression of costimulatory molecules. Notably, the TCF1+ subset displays exclusive proliferative potential and could differentiate into TCF1- effector cells upon antigenic stimulation. Pathway analyses support the role of TCF1+ and TCF1- subsets as resource cells and effector cells, respectively. Furthermore, the TCF1+ CD8+ T cell subset is primarily present in the spleen and exhibits a resident phenotype. These findings provide insight into the differentiation of allogeneic and xenogeneic CD8+ T cells and have implications for the development of immunotherapeutic strategies targeting acute GvHD.

Inflammatory cytokines and depression symptoms following hematopoietic cell transplantation

Increased synthesis and release of inflammatory signalling proteins is common among individuals with hematologic malignancies undergoing hematopoietic cell transplantation (HCT) due to intensive conditioning regimens and complications such as graft-versus-host-disease and infections. Prior research indicates that inflammatory responses can activate central nervous system pathways that evoke changes in mood. This study examined relationships between markers of inflammatory activity and depression symptoms following HCT. Individuals undergoing allogeneic (n = 84) and autologous (n = 155) HCT completed measures of depression symptoms pre-HCT and 1, 3, and 6 months post-HCT. Proinflammatory (IL-6, TNF-α) and regulatory (IL-10) cytokines were assessed by ELISA in peripheral blood plasma. Mixed-effects linear regression models indicated that patients with elevated IL-6 and IL-10 reported more severe depression symptoms at the post-HCT assessments. These findings were replicated when examining both allogeneic and autologous samples. Follow-up analyses clarified that relationships were strongest for neurovegetative, rather than cognitive or affective, symptoms of depression. These findings suggest that anti-inflammatory therapeutics targeting an inflammatory mediator of depression could improve quality of life of HCT recipients.

miR-155 and miR-92 levels in ALL, post-transplant aGVHD, and CMV: possible new treatment options

BACKGROUND

Acute lymphoblastic leukemia (ALL) is a malignancy that leads to altered blast cell proliferation, survival, and maturation and eventually to the lethal accumulation of leukemic cells. Recently, dysregulated expression of various micro-RNAs (miRNAs) has been reported in hematologic malignancies, especially ALL. Cytomegalovirus infection can induce ALL in otherwise healthy individuals, so a more detailed evaluation of its role in ALL-endemic areas like Iran is required.

METHODS

In this cross-sectional study, 70 newly diagnosed adults with ALL were recruited. The expression level of microRNA-155(miR-155) and microRNA-92(miR-92) was evaluated by real-time SYBR Green PCR. The correlations between the miRNAs mentioned above and the severity of disease, CMV infection, and acute graft vs. host disease after hematopoietic stem cell transplantation (HSCT) were assessed. B cell and T cell ALL distinction in the level of miRNAs was provided.

RESULTS

After the statistical analysis, our results indicated a marked increase in the expression of miR-155 and miR-92 in ALL patients vs. healthy controls (*P = 0.002-*P = 0.03, respectively). Also, it was shown that the expression of miR-155 and miR-92 was higher in T cell ALL compared to B cell ALL (P = 0.01-P = 0.004, respectively), CMV seropositivity, and aGVHD.

CONCLUSION

Our study suggests that the plasma signature of microRNA expression may act as a powerful marker for diagnosis and prognosis, providing knowledge outside cytogenetics. Elevation of miR-155 in plasma can be a beneficial therapeutic target for ALL patients, with consideration of higher plasma levels of miR-92 and miR-155 in CMV + and post-HSCT aGVHD patients.

Role of Multiparametric Ultrasound in Evaluating Hepatic Acute Graft-versus-Host Disease: An Animal Study

OBJECTIVE

Hepatic acute graft-versus-host disease (aGVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT) and is one of the leading causes of early non-recurrent death. The current diagnosis is based mainly based on clinical diagnosis, and there is a lack of non-invasive quantitative diagnosis methods. We propose a multiparametric ultrasound (MPUS) imaging method and explore its effectiveness in evaluating hepatic aGVHD.

METHODS

In this study, 48 female Wistar rats were used as receptors and 12 male Fischer 344 rats were used as donors for allo-HSCT to establish aGVHD models. After transplantation, 8 rats were randomly selected for ultrasonic examination weekly, including color Doppler ultrasound, contrast-enhanced ultrasound (CEUS) and shear wave dispersion (SWD) imaging. The values of nine ultrasonic parameters were obtained. Hepatic aGVHD was subsequently diagnosed by histopathological analysis. A classification model for predicting hepatic aGVHD was established using principal component analysis and support vector machines.

RESULTS

According to the pathological results, the transplanted rats were categorized into the hepatic aGVHD and non-GVHD (nGVHD) groups. All parameters obtained by MPUS differed statistically between the two groups. The first three contributing percentages of principal component analysis results were resistivity index, peak intensity and shear wave dispersion slope, respectively. The accuracy of classifying aGVHD and nGVHD using support vector machines reached 100%. The accuracy of the multiparameter classifier was significantly higher than that of the single parameter.

CONCLUSION

The MPUS imaging method has proven to be useful in detecting hepatic aGVHD.

Efficacy of shear wave dispersion imaging for viscoelastic assessment of the liver in acute graft-versus-host disease rats

BACKGROUND

To investigate the feasibility of using shear wave dispersion (SWD) imaging to evaluate hepatic acute graft-versus-host disease (aGVHD) in a rat model.

METHODS

To establish an aGVHD model, 30 Wistar rats were subjected to bone marrow transplantation, 10 Fischer 344 rats were used as donors, and 6 Wistar rats were used as the control group. Each week, 6 rats were randomly chosen and divided into groups of 1 week (1 w) to 5 weeks (5 w). For each subgroup, the rats received a clinical index assessment and shear wave dispersion (SWD) examination with 2 quantitative values, shear wave (SW) speed and SWD slope. The histological characteristics were then used as the reference standard to divide the rats into the aGVHD group and the no aGVHD (nGVHD) group.

RESULTS

In the 2 weeks (2 w) group, only SWD slope [median: 7.26, interquartile range (IQR): 7.04 to 7.31] showed a significant increase in the measured value (P<0.05). The value of the 3 weeks (3 w) group (median: 7.88, IQR: 7.84 to 8.49) significantly increased compared with the 2 w value (P<0.05). Although the value increased gradually from week 3 to week 5, it had no statistical significance (P>0.05). The SW speed [mean ± standard deviation (SD): 1.54±0.11, 95% confidence interval (CI): 1.48 to 1.59] and SWD slope (mean ± SD: 8.29±0.56, 95% CI: 7.99 to 8.59) of the aGVHD group were higher than those of the control group and the nGVHD group (P<0.001). The correlation of SWD slope with pathological grade was the highest (r=0.798, P<0.01), followed by SW speed (r=0.785, P<0.01), and the correlation of clinical index with pathological grade was the lowest (r=0.751, P<0.01). In addition, the area under the receiver operating characteristic (ROC) curve (AUC) value of aGVHD using the SWD slope was 0.844 (95% CI: 0.67 to 0.95, sensitivity: 93.75%, specificity: 78.57%), which was higher than the AUC of both SW speed and clinical index, and the difference was statistically significant compared to the AUC of the clinical index.

CONCLUSIONS

The SWD slope could show significant abnormalities earlier than SW speed and clinical index and is also more consistent with the change in aGVHD severity level. The SWD slope may help in detecting hepatic aGVHD during ultrasound SWD examination.

Resolution of Inflammation in Acute Graft-Versus-Host-Disease: Advances and Perspectives

Inflammation is an essential reaction of the immune system to infections and sterile tissue injury. However, uncontrolled or unresolved inflammation can cause tissue damage and contribute to the pathogenesis of various inflammatory diseases. Resolution of inflammation is driven by endogenous molecules, known as pro-resolving mediators, that contribute to dampening inflammatory responses, promoting the resolution of inflammation and the recovery of tissue homeostasis. These mediators have been shown to be useful to decrease inflammatory responses and tissue damage in various models of inflammatory diseases. Graft-versus-host disease (GVHD) is a major unwanted reaction following allogeneic hematopoietic stem cell transplantation (allo-HSCT) and is characterized by an exacerbated inflammatory response provoked by antigen disparities between transplant recipient and donor. There is no fully effective treatment or prophylaxis for GVHD. This review explores the effects of several pro-resolving mediators and discusses their potential use as novel therapies in the context of GVHD.

Activated CD4 + T lymphocyte is a potential biomarker for acute graft-vs.-host disease after hematopoietic stem cell transplantation in children with transfusion-dependent β-thalassemia

BACKGROUND

Acute graft-vs.-host disease (aGVHD) is still one of the most common and life-threatening complications of allogeneic hematopoietic stem cell transplantation (HSCT). Whether or not the level of activated T lymphocytes rises before the onset of aGVHD is unknown. We explored the possibility of T lymphocytes as biomarkers for early prediction of aGVHD in children with transfusion-dependent β-thalassemia (TDTβ).

METHODS

We retrospectively analyzed the characteristics of T lymphocyte subsets before and 14 days after HSCT in children with TDTβ who developed aGVHD. Data from 95 children (Age ≤ 14 years) who underwent allogeneic HSCT from January 2020 to December 2021 were collected. Patients were divided into non-aGVHD group (n = 55) and aGVHD group (n = 40), and aGVHD group was divided into two subgroups: grade I aGVHD (n = 16) and grade II-IV aGVHD (n = 24). Receiver operating characteristic curve (ROC) analysis was performed to predict aGVHD.

RESULTS

Before preconditioning in non-aGVHD and aGVHD groups, there was no significant difference in all lymphocyte subsets and ratio of CD4 + /CD8 + T cells. On day 14 post-transplantation in non-aGVHD and aGVHD groups, the absolute concentrations per μl blood of T cells, CD4 + T cells, CD8 + T cells, activated CD4 + T cell and NK cells, were 69.73 (14.70, 137.77) and 140.36 (65.06, 293.42), 10.00 (2.35, 23.59) and 35.91 (12.41, 68.71), 37.25 (5.82, 84.36) and 89.99 (35.83, 180.81), 0.52 (0.17, 2.20) and 4.08 (0.91, 11.12), 43.86 (15.00, 91.31) and 26.35 (15.19, 49.39), respectively. On day + 14 (14 days post-transplantation), the differences in all cell subsets and the ratio of CD4 + /CD8 + T cells were not statistically significant between grade I aGVHD and grade II-IV aGVHD subgroups. The absolute concentrations of CD8 + T cells in grade I aGVHD were significantly higher than in grade II-IV aGVHD [128.21 (61.11, 258.91) vs. 60.81 (21.59, 176.38), P = 0.057]. AUC of NK cells, CD8 + T cells, T cells, CD4 + T cells, and CD4 + CD25 + T cells were 0.6275, 0.6839, 0.7068, 0.7241, and 0.7589, and cut-off values were 73.75 (97.50, 34.55), 146.90 (37.50, 94.55), 187.30 (45.00, 90.91), 18.95 (70.00, 72.73), and 3.24 (52.50, 87.27), respectively. The AUC of the combined CD4 + CD25 + T cells and CD8 + T cells, CD4 + CD25 + T cells and T cells, CD4 + CD25 + T cells and CD4 + T cells, CD4 + CD25 + T cells and NK cells, respectively, were 0.7500, 0.7598, 0.7750, and 0.8050.

CONCLUSION

Our findings demonstrate that level of activated CD4 + T cells on day + 14 (post-HSCT) is a valuable biomarker for predicting aGVHD in children with TDTβ and CD8 + T cells could likely be a biomarker for severe aGVHD.

Cyclosporin A: A Repurposable Drug in the Treatment of COVID-19?

Coronavirus disease 2019 (COVID-19) is now at the forefront of major health challenge faced globally, creating an urgent need for safe and efficient therapeutic strategies. Given the high attrition rates, high costs, and quite slow development of drug discovery, repurposing of known FDA-approved molecules is increasingly becoming an attractive issue in order to quickly find molecules capable of preventing and/or curing COVID-19 patients. Cyclosporin A (CsA), a common anti-rejection drug widely used in transplantation, has recently been shown to exhibit substantial anti-SARS-CoV-2 antiviral activity and anti-COVID-19 effect. Here, we review the molecular mechanisms of action of CsA in order to highlight why this molecule seems to be an interesting candidate for the therapeutic management of COVID-19 patients. We conclude that CsA could have at least three major targets in COVID-19 patients: (i) an anti-inflammatory effect reducing the production of proinflammatory cytokines, (ii) an antiviral effect preventing the formation of the viral RNA synthesis complex, and (iii) an effect on tissue damage and thrombosis by acting against the deleterious action of angiotensin II. Several preliminary CsA clinical trials performed on COVID-19 patients report lower incidence of death and suggest that this strategy should be investigated further in order to assess in which context the benefit/risk ratio of repurposing CsA as first-line therapy in COVID-19 is the most favorable.

Transitioning tacrolimus to sirolimus in allogeneic hematopoietic cell transplantation

OBJECTIVES

Calcineurin inhibitor (CNI) use for acute graft-versus-host disease (aGVHD) prophylaxis in allogeneic hematopoietic cell transplantation (allo-HCT) recipients has been associated with toxicities. Toxicities may be managed by converting CNI to sirolimus as often done in solid organ transplantation. This study aimed to characterize allo-HCT patients who completely transitioned from tacrolimus to sirolimus and evaluate the incidence of aGVHD within 100 days post-transition, overall survival (OS), and incidence of relapse.

METHODS

Safety and efficacy data were collected at baseline and at day 30 and 90 post-transition from tacrolimus to sirolimus and at one-year post-HCT.

RESULTS

Most patients who transitioned had acute leukemia, received a matched unrelated donor allo-HCT, and transitioned due to nephrotoxicity or neurotoxicity. The resolution rate was 83% and 48% in the nephrotoxicity group, 78% and 61% in the neurotoxicity group, 33% and 33% in the group that developed both nephrotoxicity and transplant-associated thrombotic microangiopathy at 30 and 90 days of assessments, respectively. Patients who transitioned before day 55 post-allo-HCT were more likely to develop new or worsening aGVHD. The one-year OS and relapse rates were 37% and 20%, respectively.

CONCLUSIONS

The conversion from tacrolimus to sirolimus demonstrates promising resolution of acute toxicities; however, overall mortality remains high.

Diverting Enterostomy Improves Overall Survival of Patients with Severe Steroid-Refractory Gastrointestinal Acute Graft-versus-host Disease

OBJECTIVE

To evaluate the benefit of diverting enterostomy (DE) in patients with severe steroid-refractory (SR) gastrointestinal acute graft-versus-host-disease (GI-aGVHD) following allogeneic hematopoietic stem-cell transplantation (ASCT).

SUMMARY AND BACKGROUND DATA

Severe GI-aGVHD refractory to the first line steroid therapy is a rare but dramatic life-threatening complication. Second lines of immunosuppressors have limited effects and increase the risk of sepsis. Data suggest that limiting GI bacterial translocation by DE could restrain severe GI-aGVHD.

METHODS

From 2004 to 2018, we retrospectively reviewed all consecutive patients undergoing ASCT for hematologic malignancies who developed severe SR GI-aGVHD. We compared patients in whom a proximal DE was performed (Enterostomy group) with those not subjected to DE (Medical group). The primary endpoint was the 1-year overall survival (OS) measured from the onset of GI-aGVHD. Secondary endpoints were the 2-year OS and causes of death.

RESULTS

Of the 1295 patients who underwent ASCT, 51 patients with severe SR GI-aGVHD were analyzed (13 in Enterostomy group and 38 in Medical group). Characteristics of patients, transplantation modalities, and aGVHD severity were similar in both groups. The 1-year OS was better after DE (54% vs. 5%, P = 0.0004). The 2-year OS was also better in "Enterostomy group" (31% vs. 2.5%; P = 0.0015), with a trend to lower death by sepsis (30.8% vs. 57.9%; P = 0.091).

CONCLUSION

DE should be considered for severe GI-aGVHD as soon as resistance to the corticosteroid is identified.

Understanding the Process and Challenges for Return-to-Work Post-Hematopoietic Cell Transplantation from a Musculoskeletal Perspective: A Narrative Review

The current paper seeks to inform healthcare professionals on how adapting various components of return to work (RTW) programs that are already in use by other musculoskeletal rehabilitation settings can help optimize return to work process for patients with or without musculoskeletal manifestations, posthematopoietic cell transplantation. Since there is no universally agreed RTW structure for hematopoietic cell transplant patients, a narrative approach has been taken utilizing evidence from the existing musculoskeletal return to work assessment publications to help draw parallel for the hematopoietic cell transplant patients. Databases were searched including PUBMED, CINHAL, AMED, SCOPUS, and Cochrane using keywords RTW, functional restoration program, hematopoietic cell transplant, bone marrow transplant, stem cell transplant, and musculoskeletal functional assessment. The authors have managed to outline and propose a structured RTW assessment and monitoring program which can aid in getting patients back to employment by utilizing the functional capacity and job evaluation to help hematopoietic cell transplantation patients reintegrate socially. Patients undergoing hematopoietic cell transplant require additional support and a robust assessment system to allow safe RTW. The proposed model of RTW assessment can prove to be beneficial in helping patients return to work safely. Clinical Significance. To acknowledge the individuality in functional limitation is important in determining not only the rehab needs but also the RTW capabilities. The proposed RTW plan not only promotes an individualized approach to patients but also provides a structure for return to work assessments for hematopoietic cell transplantation patients, thus, eliminating the need for guess work by healthcare professionals. In line with the International Classification of Functioning, Disability, and Health (ICF) recommendations, a RTW assessment combined with a job evaluation helps healthcare professionals and stakeholders to understand the unique challenges and strengths of a patient and thereby design an individualized therapy approach.

Assessment of ST2 and Reg3a levels in patients with acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Background/aim

Graft-versus-host disease (GVHD) is a crucial complication leading to significant morbidity and mortality allogeneic hematopoietic stem cell transplantation which occurs in approximately half of the transplant recipients. Suppression of tumorigenicity 2 (ST2) and regenerating islet-derived 3-alpha(Reg3a) might be important biomarkers to predict acute GVHD.

Materials and methods

In the present study, blood samples were collected from 17 patients with acute GVHD and 12 control patients after allogeneic stem cell transplantation. ST2 and Reg3a were measured in plasma samples compared in patients with acute GVHD and the controls.

Results

Median age of the study population was 42 years (range 19–49). When compared to controls, the mean ST2 levels was significant higher in acute GVHD (9794 ng/dL vs. 2646 ng/dL, P = 0.008). Mean Reg3a level did not show significant difference between control and acute GVHD group (8848 ng/dL vs. 5632 ng/dL, respectively, P = 0.190).

Conclusion

The ST2 level might be used as a significant biomarker for predicting acute GVHD.

Profile of Hepatobiliary Dysfunction in Hematopoietic Stem Cell Transplant Recipients - An Indian Perspective

BACKGROUND/AIMS

Hematopoietic stem cell transplantation (HSCT) is an established curative modality for various hematological malignancies and other diseases. Hepatobiliary dysfunction and subsequent sequelae constitute a common cause of morbidity and mortality in post-transplant scenario. However, data among Indian HSCT recipients is lacking.

METHODS

One hundred and one HSCT recipients (37 prospective and 64 retrospective) were followed up for hepatobiliary dysfunction in the post-transplant period. The causes for hepatobiliary dysfunction were categorized as sinusoidal obstruction syndrome (SOS), formerly known as veno-occlusive disease (VOD); acute and chronic graft-versus- host disease (GVHD); drug-induced liver injury (DILI); viral infections and miscellaneous causes including bacterial, fungal and unknown causes based on clinical and laboratory evidence.

RESULTS

Among the 101 transplants, 56.44% (n = 57) were allogenic transplants, and 43.56% (n = 44) were autologous transplants. Hepatobiliary dysfunction was observed among 71 (70.30%) patients in first 30 days and overall, among 78 (77.23%) patients. Incidence of hepatobiliary dysfunction was higher among allogenic transplant patients compared to autologous transplants (91.23% vs. 59.09%, p < 0.001). The most common cause of hepatobiliary dysfunction reported was Drug-induced liver injury (DILI). In most cases, however, hepatobiliary dysfunction was multifactorial. Sinusoidal obstruction syndrome (15.79%), acute liver GVHD (31.58%), chronic liver GVHD (33.33%) and viral infection/reactivation (26.32%) were reported only in allogenic transplant patients. 15 (14.85%) patients died of which 14 patients had hepatobiliary dysfunction, commonest cause being infections.

CONCLUSION

Our study reported a higher incidence of hepatobiliary dysfunction among Indian population post HSCT and was associated with significant mortality. In majority of the cases, the cause is multifactorial and pose a diagnostic dilemma and challenges in therapy.

Phase II trial of natalizumab with corticosteroids as initial treatment of gastrointestinal acute graft-versus-host disease

The α4ß7 integrin is upregulated on naive and memory T cell subsets in patients who subsequently develop gastrointestinal (GI) acute GVHD. Natalizumab (Tysabri^®, Biogen Inc.) acts against the α4 subunit that mediates homing of lymphocytes to the GI tract. We initiated a phase II study of natalizumab with corticosteroids for initial treatment of acute GI GVHD. In total, 300 mg IV of natalizumab was given, with steroids initiated up to 3 days prior. Twenty-one subjects were treated, median age was 63 years (range 38-74), and 15 (71%) were male. Eighteen (86%) underwent RIC, 15 (71%) received MUD, and all received PBSCs. Overall GVHD at enrollment was grade II in 4 and grade III in 17. The primary endpoint, day 56 GVHD-free survival rate, was attained in 33.3%. The overall response rate at day 28 and 56 was 57% and 52%, respectively. Six of eight CRs were durable for 1 year. Five experienced toxicity possibly related to natalizumab and ten had infections before day 100. 2-year OS was 43% (95% CI 22-62%) and 2-year NRM was 52% (95% CI 29-71%). Natalizumab with corticosteroids as initial treatment of acute GI GVHD is safe, effective, and durable.

Applications of PET in Diagnosis and Prognosis of Leukemia

As a malignant hematopoietic stem cell disease, leukemia remains life-threatening due to its increasing incidence rate and mortality rate. Therefore, its early diagnosis and treatment play a very important role. In the present work, we systematically reviewed the current applications and future directions of positron emission tomography (PET) in patients with leukemia, especially ¹⁸F-FDG PET/CT. As a useful imaging approach, PET significantly contributes to the diagnosis and treatment of different types of leukemia, especially in the evaluation of extramedullary infiltration, monitoring of leukemia relapse, detection of Richter’s transformation (RT), and assessment of the inflammatory activity associated with acute graft versus host disease. Future investigations should be focused on the potential of PET/CT in the prediction of clinical outcomes in patients with leukemia and the utility of novel radiotracers.

Trametinib Attenuates Delayed Rejection and Preserves Thymic Function in Rat Lung Transplantation

Delayed immunological rejection after human lung transplantation causes chronic lung allograft dysfunction, which is associated with high mortality. Delayed rejection may be attributable to indirect alloantigen presentation by host antigen-presenting cells; however, its pathophysiology is not fully understood. The mitogen-activated protein kinase pathway is activated in T cells upon stimulation, and we previously showed that the MEK inhibitor, trametinib, suppresses graft-versus-host disease after murine bone marrow transplantation. We investigated whether trametinib suppresses graft rejection after two types of rat lung transplantation and analyzed its immunological mode of action. Major histocompatibility complex-mismatched transplantation from brown Norway rats into Lewis rats and minor histocompatibility antigen-mismatched transplantation from Fischer 344 rats into Lewis rats were performed. Cyclosporine (CsA) and/or trametinib were administered alone or consecutively. Acute and delayed rejection, lymphocyte infiltration, and pulmonary function were evaluated. Administration of trametinib after CsA suppressed delayed rejection, reduced inflammatory cell infiltration and fibrosis within the graft, and preserved pulmonary functions at Day 28. Trametinib suppressed functional differentiation of T and B cells in the periphery but preserved thymic T cell differentiation. Donor B cells within the graft disappeared by Day 14, indicating that delayed graft rejection at Day 28 was mainly due to indirect presentation by host antigen-presenting cells. Finally, trametinib administration without CsA preconditioning suppressed rejection after minor histocompatibility antigen-mismatched transplantation. Trametinib attenuates delayed rejection upon major histocompatibility complex-mismatched transplantation by suppressing indirect presentation and is a promising candidate to treat chronic lung allograft dysfunction in humans.

A Phase 3, Single-Arm, Prospective Study of Remestemcel-L, Ex Vivo Culture-Expanded Adult Human Mesenchymal Stromal Cells for the Treatment of Pediatric Patients Who Failed to Respond to Steroid Treatment for Acute Graft-versus-Host Disease

Steroid-refractory acute graft-versus-host disease (SR-aGVHD) following hematopoietic cell transplantation (HSCT) is associated with poor clinical outcomes. Currently, there are no safe and effective therapies approved for use in the pediatric population under the age of 12 years. Accordingly, there is an urgent need for new treatments that are safe, well tolerated, and effective in managing this debilitating and potentially fatal complication of HSCT. In early phase clinical trials, mesenchymal stromal cells (MSCs) have demonstrated efficacy in the treatment of acute GVHD (aGVHD) in pediatric patients. We now report the results of a phase 3, prospective, single-arm, multicenter study (NCT02336230) in 54 children with primary SR-aGVHD who were naive to other immunosuppressant therapies for aGVHD treated with MSC product (remestemcel-L) dosed at 2 × 10⁶ cells/kg twice weekly for 4 weeks. Remestemcel-L therapy significantly improved day 28 overall response rate (OR) compared with the prespecified control OR value of 45% (70.4% versus 45%, P = .0003). The statistically significant OR (70.4%) was sustained through day 100, including an increase in complete response from 29.6% at day 28 to 44.4% at day 100. Overall survival was 74.1% at day 100 and 68.5% at day 180. Overall response in all participants at day 28 was highly predictive of improved survival through 180 days, and survival was significantly greater in day 28 responders compared with nonresponders through day 100 (86.8% versus 47.1% for responders and nonresponders, respectively, P = .0001) and through day 180 (78.9% versus 43.8%, P = .003). Remestemcel-L was well tolerated with no identified infusion-related toxicities or other safety concerns. This study provides robust, prospective evidence of the safety, tolerability, and efficacy of remestemcel-L as first-line therapy after initial steroid failure in pediatric SR-aGVHD.

Acute Graft-Versus-Host Disease: A Brief Review

Graft‐versus‐host disease (GvHD) is an important complication that can be observed after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Acute GvHD (aGvHD) is seen after allo-HSCT and the incidence of aGvHD is around 30%-50%. aGvHD prophylaxis is essential in patients undergoing allo-HSCT. Initial therapy for aGvHD is steroids. Prognosis is poor in aGvHD patients not responding to steroids. In this article, the pathobiology, clinical findings, prophylaxis, and treatment of aGvHD will be summarized.

Lipocalin-2 levels in acute and chronic graft-versus-host disease following allogeneic hematopoietic stem cell transplantation

Lipocalin-2 (LCN2) is an immunomodulatory protein holding major metabolic and immune functions. It is involved in several inflammatory processes and induced by cytokines of the interleukin-1 family known as contributors to the morbidity in graft-versus-host disease (GVHD) following hematopoietic stem cell transplantation (HSCT). The possible role of LCN2 in predicting outcome and course of illness has never been elucidated in patients undergoing HSCT for hematologic malignancies. We conducted a prospective cohort study including 40 patients following autologous or allogeneic HSCT by collecting plasma samples at seven time points with respect to GVHD, relapse, and outcome. LCN2 levels were significantly increased in acute patients with GVHD compared with autologous and healthy controls (125.7 ng/mL vs. 65.9 and 71.4 ng/mL) and correlated with its severity. Similarly, LCN2 levels were significantly elevated in chronic GHVD compared with autologous and healthy controls (295.0 ng/mL vs. 54.9 and 76.5 ng/mL). Moreover, LCN2 correlated with mortality. The suspected role of LCN2 as a predictive parameter for outcome and prognosis needs to be further investigated.

Dermatological Disorders following Liver Transplantation: An Update

Patients undergoing liver transplantation (LT) are at a high risk of dermatological complications compared to the general population as a result of long-term use of immunosuppressant. However, the risk is not as high as other solid organ transplantations (SOT), particularly for skin cancer. The liver is considered as an immune privileged organ since it has a low prevalence of humoral rejection in contrast to other SOT, and thus, LT requires a minimal amount of immunosuppressants compared to other SOT recipients. However, because of the large volume of the liver, patients with LT have higher donor lymphocytes that sometimes may trigger graft-versus-host-disease, yet it is rare. On the other hand, the vast majority of the nonspecific dermatological lesions linked with cirrhosis improve after removal of diseased liver or due to the immunosuppressant used after LT. Nevertheless, dermatological infections related to bacteria, viruses, and fungus after LT are not uncommon. Additionally, the incidence of IgE-mediated food allergies develops in 12.2% of LT patients and may present as life-threatening conditions such as urticaria and/or angioedema and hypersensitivity. Moreover, skin malignancies after LT are a matter of concern. Thus, posttransplant dermatological care should be provided to all LT patients for any suspicious dermatological lesions. Our goal is to give an outline of the dermatological manifestation associated with LT for the clinicians by collecting the published data from all archived case reports.

The oral microbiome of patients undergoing treatment for severe aplastic anemia: a pilot study

The microbiome, an intriguing component of the human body, composed of trillions of microorganisms, has prompted scientific exploration to identify and understand its function and role in health and disease. As associations between microbiome composition, disease, and symptoms accumulate, the future of medicine hinges upon a comprehensive knowledge of these microorganisms for patient care. The oral microbiome may provide valuable and efficient insight for predicting future changes in disease status, infection, or treatment course. The main aim of this pilot study was to characterize the oral microbiome in patients with severe aplastic anemia (SAA) during their therapeutic course. SAA is a hematologic disease characterized by bone marrow failure which if untreated is fatal. Treatment includes either hematopoietic stem cell transplantation (HSCT) or immunosuppressive therapy (IST). In this study, we examined the oral microbiome composition of 24 patients admitted to the National Institutes of Health (NIH) Clinical Center for experimental SAA treatment. Tongue brushings were collected to assess the effects of treatment on the oral microbiome. Twenty patients received standard IST (equine antithymocyte globulin and cyclosporine) plus eltrombopag. Four patients underwent HSCT. Oral specimens were obtained at three time points during treatment and clinical follow-up. Using a novel approach to 16S rRNA gene sequence analysis encompassing seven hypervariable regions, results demonstrated a predictable decrease in microbial diversity over time among the transplant patients. Linear discriminant analysis or LefSe reported a total of 14 statistically significant taxa (p < 0.05) across time points in the HSCT patients. One-way plots of relative abundance for two bacterial species (Haemophilus parainfluenzae and Rothia mucilaginosa) in the HSCT group, show the differences in abundance between time points. Only one bacterial species (Prevotella histicola) was noted in the IST group with a p value of 0.065. The patients receiving immunosuppressive therapy did not exhibit a clear change in diversity over time; however, patient-specific changes were noted. In addition, we compared our findings to tongue dorsum samples from healthy participants in the Human Microbiome Project (HMP) database and found among HSCT patients, approximately 35% of bacterial identifiers (N = 229) were unique to this study population and were not present in tongue dorsum specimens obtained from the HMP. Among IST-treated patients, 45% (N = 351) were unique to these patients and not identified by the HMP. Although antibiotic use may have likely influenced bacterial composition and diversity, some literature suggests a decreased impact of antimicrobials on the oral microbiome as compared to their effect on the gut microbiome. Future studies with larger sample sizes that focus on the oral microbiome and the effects of antibiotics in an immunosuppressed patient population may help establish these potential associations.

Comparison of Myeloablative Versus Reduced-Intensity Conditioning Regimens for Allogeneic Hematopoietic Stem Cell Transplantation in Acute Myeloid Leukemia: A Cohort Study

Objective

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment modality for a variety of malignant and non-malignant hematologic disorders. Myeloablative conditioning (MAC) and reduced-intensity conditioning (RIC) regimens could have different clinical outcomes. This purpose of this study was to assess the long-term outcome of MAC versus RIC regimens in patients with acute myeloid leukemia (AML) undergoing allogeneic HSCT.

Materials and Methods

We retrospectively compared long-term outcomes with MAC and RIC regimens in patients with AML who underwent allo-HSCT at our tertiary transplantation center.

Results

We analyzed survival outcomes after MAC-HSCT versus RICHSCT among 107 adult patients with AML diagnosed from 2001 through 2017. Of those, 44 patients underwent a MAC regimen, whereas 63 patients received a RIC regimen. The median follow-up time was 37 months (range: 6-210) for the entire group. The 3-year overall survival (OS) for RIC and MAC patients was 67% and 60%, respectively (p>0.05). The 3-year progression-free survival (PFS) for RIC and MAC patients was 88% and 77%. In multivariate analysis, the type of conditioning regimen (RIC vs. MAC) did not influence PFS (p=0.24). Acute graft-versus-host disease (GVHD) was seen in five of the RIC patients and 9 of the MAC patients. Chronic GVHD was seen in 16 of the RIC patients and 6 of the MAC patients. There was no significant difference between the two groups in terms of acute GVHD (p=0.089), but there was a significant difference between the two groups in terms of chronic GVHD (p=0.03).

Conclusion

This retrospective analysis confirmed that MAC and RIC regimens had a consistently equivalent rate of OS and PFS in AML patients who underwent allo-HSCT. The choice of MAC versus RIC conditioning regimen might be decided on the basis of patient and disease characteristics.

Impact of Blood Count Recovery-based Complete Remission Before Allogeneic Hematopoietic Stem Cell Transplantation on Survival in Patients With Acute Myeloid Leukemia

BACKGROUND

Patients who achieve complete remission (CR) with incomplete blood count recovery (CRi) in acute myeloid leukemia (AML) have inferior overall survival and lower progression-free survival. The aim of this study was to define whether blood count recovery-based CR before allogeneic hematopoietic stem cell transplantation (alloHSCT) had an impact on survival in patients with AML.

MATERIALS AND METHODS

This study has been performed in a retrospective manner. One hundred one patients with AML who received an alloHSCT in our transplant center at Hacettepe University Hospital between the years 2001 and 2018 were evaluated. CRi were defined as bone marrow CR with absolute neutrophil count < 1000/mm³ and/or platelet count < 100.000/mm³. CR and CRi were confirmed just before alloHSCT in bone marrow and peripheral blood, respectively.

RESULTS

A total of 101 patients were entered into the study between 2001 and 2018. Median follow-up for all survivors was 38 months (range, 6-220 months). The 5-year overall survival for patients who were in CRi and patients who were in CR before transplantation were 58% and 67%, respectively (P = .68). The 5-year progression-free survival for patients who were in CRi and patients who were in CR before transplantation were 68% and 64%, respectively (P = .99).

CONCLUSION

In conclusion, we observed equivalent posttransplant outcomes between patients who were in CR and patients who were in CRi before alloHSCT. We assume that alloHSCT eliminated the negative effect of pre-transplant blood count levels.

Notch inhibition enhances graft-versus-leukemia while reducing graft-versus-host disease

Graft-versus host disease (GVHD) remains the most significant complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Dissociation of graft versus-leukemia (GVL) activity from GVHD has yet to be achieved. In this study, we used γ-secretase inhibitor (GSIs, DAPT) to inhibit Notch signaling in GVHD and GVL murine model. We found that CD11c⁺CD80⁺ dendritic cells (DCs) were up-regulated but did not enhance GVHD. Regulatory T cells (Tregs) and central memory T cells that express high levels of CD62L and CD44 had an expansion after Notch inhibition. Reduced Tumor Necrosis Factor-α and increased Interferon-γ production were found, which might be ascribed to the expansion of Tregs and central memory T cells, and result in increased sensitivity of tumor cells to cytotoxic T lymphocyte activity. Fas Receptor-Fas Ligand interaction plays a critical role in GVL instead of aGVHD. Fas Ligand expressions were similar in recipients with or without Notch inhibition, suggesting that GVL activity was maintained. We showed that Notch inhibition could enhances GVL while reducing GVHD via modulating host DCs and donor T cell activity, and the production of inflammatory cytokines.

18 F-FDG PET/CT in Extensive Graft-Versus-Host Disease of the Gastrointestinal Tract Following Autologous Stem Cell Transplantation

Graft-versus-host-disease (GVHD) following stem cell transplantation (SCT) is a common complication in patients that have undergone allogenic SCT but rare in recipients of autologous SCT. Gastro-intestinal tract (GIT)-GVHD can be difficult to diagnose due to non-specific symptoms such as fever, nausea, diarrhea, and vomiting; a histological confirmation is therefore required. Here, we present the findings of a whole-body ¹⁸FDG PET/CT with extensive and multifocal involvement of the GIT in a patient that developed severe acute GVHD 93 days post autologous SCT for Hodgkin’s lymphoma. PET and CT findings included characteristic patterns of bowel inflammation with bowel wall thickening, mural stratification and enhancement with high FDG-uptake of the involved regions, as well as typical extra intestinal findings such as ascites, engorgement of the vasa recti and stranding of the mesenteric fat. Although, the above-mentioned findings are not exclusive to GIT-GVHD and can be seen in other settings of inflammatory bowel disease such as enterocolitis or Mb Crohn our findings were used for targeted biopsy that confirmed acute GIT-GVHD. This case demonstrates that ¹⁸F-FDG-PET/CT can be a valuable non-invasive tool in mapping the activity and distribution of intestinal GVHD and direct for targeted biopsies of involved regions.

Update of humanized animal disease models in studying Graft-versus-host disease

Graft-versus-host disease (GVHD) is a severe adverse effect that results from bone marrow or peripheral blood cells transplantation and has a high rate of mortality. About 50% of the patients are accompanied with acute Graft-versus-Host Disease (aGVHD) after bone marrow cell transplantation and need systematic treatment. It has an important clinical significance to evaluate the prevention and treatment effects of GVHD. The stable and reliable approaches of humanized animal models are crucial for advancing on the study the biology of GVHD. Relative models transplanting the human immune cells into the mouse body can trigger immunoreaction similar to the humans. As it is a disease triggered by human immune cells, any intervention research prior to clinical treatment has more clinical interrelations compared with the general animal models. In this review, we update the current understanding on humanized animal disease models on studying Graft-versus-host disease and expect to provide more theoretical basis to further study on Graft-versus-host disease.

Female genital tract chronic graft-versus-host disease: A narrative review

Graft-versus-host disease is one of the main causes of morbidity and mortality in patients submitted to hematopoietic stem cell transplantation. This study reviewed the prevalence of lower female genital tract graft-versus-host disease following hematopoietic stem cell transplantation. A systematic search of the literature for articles published between 1982 and 2015 was performed. A growing number of young women suffering from malignant and benign hematological diseases are receiving allogeneic hematopoietic stem cell transplantation with very satisfactory results in relation to the disease itself. However, these patients face gynecological problems due to graft-versus-host disease. Correct diagnosis and early management are needed to avoid irreversible complications.

Inhibition of 5-lipoxygenase alleviates graft-versus-host disease

Rezende et al. report that the transplant of 5-lipoxygenase (5-LO)−deficient leukocytes protects mice from GVHD. Treatment with the 5-LO inhibitor zileuton or a LTB₄ antagonist at the initial phase of the transplant achieves similar protective effects. 5-LO is a crucial contributor to tissue damage in GVHD.

Leukotriene B₄ (LTB₄), a proinflammatory mediator produced by the enzyme 5-lipoxygenase (5-LO), is associated with the development of many inflammatory diseases. In this study, we evaluated the participation of the 5-LO/LTB₄ axis in graft-versus-host disease (GVHD) pathogenesis by transplanting 5-LO–deficient leukocytes and investigated the effect of pharmacologic 5-LO inhibition by zileuton and LTB₄ inhibition by CP-105,696. Mice that received allogeneic transplant showed an increase in nuclear 5-LO expression in splenocytes, indicating enzyme activation after GVHD. Mice receiving 5-LO–deficient cell transplant or zileuton treatment had prolonged survival, reduced GVHD clinical scores, reduced intestinal and liver injury, and decreased levels of serum and hepatic LTB₄. These results were associated with inhibition of leukocyte recruitment and decreased production of cytokines and chemokines. Treatment with CP-105,696 achieved similar effects. The chimerism or the beneficial graft-versus-leukemia response remained unaffected. Our data provide evidence that the 5-LO/LTB₄ axis orchestrates GVHD development and suggest it could be a target for the development of novel therapeutic strategies for GVHD treatment.

Dynamic changes in serum cytokine levels and their clinical significance in predicting acute GVHD

To explore the clinical significance of cytokines and biochemical tests in acute graft-versus-host disease (aGVHD), we detected the concentrations of 8 cytokines and 19 conventional biochemical markers in the sera of aGVHD and non-GVHD patients throughout the process of allogeneic hematopoietic stem cell transplantation and the onset of aGVHD. Predictive models were then established using the 27 indices, and models were verified by a prospective trial. The 27 indices showed significant differences between aGVHD patients and non-GVHD control subjects (two-tailed p<0.05) prior to transplantation and before the onset of aGVHD. Our models, established by binary logistic regression on days +7 and +14, showed a significant absolute capacity of predicting grade 2∼4 aGVHD with positive and negative predictive values of at least 70%. Our data showed that the progression of aGVHD could induce dynamic changes in the levels of serum cytokines and biochemical markers. Because most of these tests were less specific for aGVHD, these changes were easily neglected in clinical work. However, by combining cytokine and biochemical tests, the established prediction model can greatly improve the ability of these biomarkers to predict the development of aGVHD one or two weeks earlier.

Humanized mouse models: Application to human diseases

Humanized mice are superior to rodents for preclinical evaluation of the efficacy and safety of drug candidates using human cells or tissues. During the past decade, humanized mouse technology has been greatly advanced by the establishment of novel platforms of genetically modified immunodeficient mice. Several human diseases can be recapitulated using humanized mice due to the improved engraftment and differentiation capacity of human cells or tissues. In this review, we discuss current advanced humanized mouse models that recapitulate human diseases including cancer, allergy, and graft-versus-host disease.

Precision monitoring of immunotherapies in solid organ and hematopoietic stem cell transplantation

Pharmacological immunotherapies are a key component of post-transplant therapy in solid-organ and hematopoietic stem cell transplantation. In current clinical practice, immunotherapies largely follow a one-size fits all approach, leaving a large portion of transplant recipients either over- or under-immunosuppressed, and consequently at risk of infections or immune-mediated complications. Our goal here is to review recent and rapid advances in precision and genomic medicine approaches to monitoring of post-transplant immunotherapies. We will discuss recent advances in precision measurements of pharmacological immunosuppression, measurements of the plasma and gut microbiome, strategies to monitor for allograft injury and post-transplant malignancies via circulating cell-free DNA, and comprehensive measurements of the B and T cell immune cell repertoire.

A Novel Xenogeneic Graft-Versus-Host Disease Model for Investigating the Pathological Role of Human CD4+ or CD8+ T Cells Using Immunodeficient NOG Mice

Graft-versus-host disease (GVHD) is a major complication of allogenic bone marrow transplantation and involves the infiltration of donor CD4⁺ and/or CD8⁺ T cells into various organs of the recipient. The pathological role of human CD4⁺ and CD8⁺ T cells in GVHD remains controversial. In this study, we established two novel xenogeneic (xeno)-GVHD models. Human CD4⁺ or CD8⁺ T cells were purified from peripheral blood and were transplanted into immunodeficient NOD/Shi-scid IL2rg^null (NOG) mice. Human CD8⁺ T cells did not induce major GVHD symptoms in conventional NOG mice. However, CD8⁺ T cells immediately proliferated and induced severe GVHD when transferred into NOG mice together with at least 0.5 × 10⁶ CD4⁺ T cells or into NOG human interleukin (IL)-2 transgenic mice. Human CD4⁺ T cell-transplanted NOG mice developed skin inflammations including alopecia, epidermal hyperplasia, and neutrophilia. Pathogenic T helper (Th)17 cells accumulated in the skin of CD4⁺ T cell-transplanted NOG mice. Further, an anti-human IL-17 antibody (secukinumab) significantly suppressed these skin pathologies. These results indicate that pathogenic human Th17 cells induce cutaneous GVHD via IL-17-dependent pathways. This study provides fundamental insights into the pathogenesis of xeno-GVHD, and these humanized mouse models may be useful as preclinical tools for the prevention of GVHD.

Genetic Association of Hematopoietic Stem Cell Transplantation Outcome beyond Histocompatibility Genes

The outcome of hematopoietic stem cell transplantation (HSCT) is controlled by genetic factors among which the leukocyte antigen human leukocyte antigen (HLA) matching is most important. In addition, minor histocompatibility antigens and non-HLA gene polymorphisms in genes controlling immune responses are known to contribute to the risks associated with HSCT. Besides single-nucleotide polymorphisms (SNPs) in protein coding genes, SNPs in regulatory elements such as microRNAs (miRNAs) contribute to these genetic risks. However, genetic risks require for their realization the expression of the respective gene or miRNA. Thus, gene and miRNA expression studies may help to identify genes and SNPs that indeed affect the outcome of HSCT. In this review, we summarize gene expression profiling studies that were performed in recent years in both patients and animal models to identify genes regulated during HSCT. We discuss SNP–mRNA–miRNA regulatory networks and their contribution to the risks associated with HSCT in specific examples, including forkheadbox protein 3 and regulatory T cells, the role of the miR-155 and miR-146a regulatory network for graft-versus-host disease, and the function of MICA and its receptor NKG2D for the outcome of HSCT. These examples demonstrate how SNPs affect expression or function of proteins that modulate the alloimmune response and influence the outcome of HSCT. Specific miRNAs targeting these genes and directly affecting expression of mRNAs are identified. It might be valuable in the future to determine SNPs and to analyze miRNA and mRNA expression in parallel in cohorts of HSCT patients to further elucidate genetic risks of HSCT.

Safety and Role of Gastrointestinal Endoscopy in the Management of Gastrointestinal Acute GVHD in Children After Hematopoietic Stem Cell Transplantation

Gastrointestinal (GI) endoscopy and biopsy is a common procedure to confirm the diagnosis of acute graft-versus-host disease (aGVHD) in children after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Its safety and benefits in aGVHD management is unclear. We aimed to review the safety and benefits of GI endoscopy and biopsy for GI-aGVHD management. From January 2000 to December 2009, 450 Children received allo-HSCT at SickKids. Seventy-nine (17.5%) patients underwent GI endoscopy and biopsy for suspicion of GI-aGVHD. GI-aGVHD grading was I (n=5), II (n=39), III (n=23), and IV (n=12). GI biopsy confirmed aGVHD in 49 (62%) patients and results were negative in 30 (38%). Thirty-two (40%) patients started treatment based on clinical criteria before procedure. Twenty-four out of 79 patients had a change in therapy because of biopsy results. Treatment change was significantly more common in patients who had a positive biopsy results compared with those with negative results (24/49 vs. 4/30, P=0.02). Comparing patients who started therapy before the biopsy results (n=32) and the remaining patients (n=47) who were not started on therapy, the biopsy results had more impact in altering/starting therapy in these patients (24/47 vs. 0/32, P<0.00001). For the 32 patients who started therapy before the procedure, the biopsy confirmed aGVHD diagnosis in 20 of them (63%). Only 1 patient (1.25%) had duodenal hematoma and needed prolong GI rest and ultimately recovered. GI endoscopy and biopsy was safe and useful in guiding therapy for GI-aGVHD.