Tirosin kinase inhibitors in chronic graft versus host disease: from bench to bedside

Clinical Progression and Manifestations of H Syndrome: A Case Report of Failed Treatment Option

BACKGROUND H syndrome is an autosomal recessive disorder of histiocytic proliferation with clinical spectrum of unique cutaneous and systemic manifestations. There is no consistent treatment for the disease, and all available options are based on case reports. Here, we present the chronological progression of a case of H syndrome with typical cutaneous manifestations that was misdiagnosed early as meningitis-induced sensorineural hearing loss and later as a non-defined autoimmune connective tissue disease. A new tried, although failed, treatment option is described as well. CASE REPORT A 31-year-old Saudi woman born of a consanguineous marriage presented to our dermatology clinic with symmetrical indurated hyperpigmented to violaceous plaques over the medial thighs, upper legs, lower back, volar wrists, and upper arms, associated with hypertrichosis. Hallux valgus of the big toes was clinically detected as well. She had a history of sensorineural deafness, diabetes mellitus, chronic anemia, and hypothyroidism. Genetic analysis of the patient showed a homozygous frameshift pathogenic variant of the SLC29A3 gene, c.243del p.(Lys81Asnfs*20). Systemic treatments in the form of methotrexate and imatinib had been tried; however, both failed to control her sclerotic cutaneous changes. CONCLUSIONS Knowing the early life presentation and the variable clinical symptoms of H syndrome is crucial in early intervention and further prevention of the non-reversible changes. Moreover, avoiding unnecessary immunosuppressive medication use is warranted in certain circumstances.

HCV Reactivation in a Patient with Hepatocellular Carcinoma Due to Sorafenib: A Case Report

The global prevalence of hepatitis C virus (HCV) infection is approximately 3%, with a post-infection chronicity rate of up to 50%-85%. HCV reactivation can occur when anti-HCV positive individuals receive antineoplastic therapy. In this study, we report a case of an anti-HCV positive patient with negative HCV RNA after 12 weeks of direct antiviral therapy. Two months later, sorafenib was used to treat hepatocellular carcinoma, and HCV reactivation occurred after 8 months of the treatment. HCV RNA was negative after 12 weeks of antiviral treatment with Sofosbuvir-velpatasvir. We also discussed the mechanism of HCV reactivation caused by sorafenib and the antiviral treatment regimen after HCV reactivation with the relevant literature.

Ras family signaling pathway in immunopathogenesis of inflammatory rheumatic diseases

The Ras (rat sarcoma virus) is a GTP-binding protein that is considered one of the important members of the Ras-GTPase superfamily. The Ras involves several pathways in the cell that include proliferation, migration, survival, differentiation, and fibrosis. Abnormalities in the expression level and activation of the Ras family signaling pathway and its downstream kinases such as Raf/MEK/ERK1-2 contribute to the pathogenic mechanisms of rheumatic diseases including immune system dysregulation, inflammation, and fibrosis in systemic sclerosis (SSc); destruction and inflammation of synovial tissue in rheumatoid arthritis (RA); and autoantibody production and immune complexes formation in systemic lupus erythematosus (SLE); and enhance osteoblast differentiation and ossification during skeletal formation in ankylosing spondylitis (AS). In this review, the basic biology, signaling of Ras, and abnormalities in this pathway in rheumatic diseases including SSc, RA, AS, and SLE will be discussed.

Harnessing and honing mesenchymal stem/stromal cells for the amelioration of graft-versus-host disease

Allogeneic hematopoietic stem cell transplantation is a deterministic curative procedure for various hematologic disorders and congenital immunodeficiency. Despite its increased use, the mortality rate for patients undergoing this procedure remains high, mainly due to the perceived risk of exacerbating graft-versus-host disease (GVHD). However, even with immunosuppressive agents, some patients still develop GVHD. Advanced mesenchymal stem/stromal cell (MSC) strategies have been proposed to achieve better therapeutic outcomes, given their immunosuppressive potential. However, the efficacy and trial designs have varied among the studies, and some research findings appear contradictory due to the challenges in characterizing the in vivo effects of MSCs. This review aims to provide real insights into this clinical entity, emphasizing diagnostic, and therapeutic considerations and generating pathophysiology hypotheses to identify research avenues. The indications and timing for the clinical application of MSCs are still subject to debate.

The Development of New Agents for Post-Hematopoietic Stem Cell Transplantation Non-Infectious Complications in Children

Hematopoietic stem cell transplantation (HSCT) is often the only curative treatment option for patients suffering from various types of malignant diseases and some non-cancerous conditions. Nevertheless, it is associated with a high risk of complications leading to transplant-related mortality and long-term morbidity. An increasing number of therapeutic and prevention strategies have been developed over the last few years to tackle the complications arising in patients receiving an HSCT. These strategies have been mainly carried out in adults and some are now being translated into children. In this manuscript, we review the recent advancements in the development and implementation of treatment options for post-HSCT non-infectious complications in pediatric patients with leukemia and other non-malignant conditions, with a special attention on the new agents available within clinical trials. We focused on the following conditions: graft failure, prevention of relapse and early interventions after detection of minimal residual disease positivity following HSCT in acute lymphoblastic and myeloid leukemia, chronic graft versus host disease, non-infectious pulmonary complications, and complications of endothelial origin.

Treatment of steroid-refractory chronic graft-versus-host disease with imatinib: Real-life experience of the Spanish group of hematopoietic transplantation (GETH)

Treatment of steroid-refractory chronic graft-versus-host disease (cGVHD) is a challenge. Here, we describe a retrospective analysis of 66 patients with steroid-refractory cGVHD treated with imatinib (starting dose of 100 mg in 70% of patients; maximum dose of 100-200 mg in 74%). Most patients had multi-organ involvement (≥2 organs, 83%), with the most affected being skin (85%), oral mucosa (55%), eyes (42%), and lungs (33%). The overall response rate was 41% (21 partial and three complete responses). The organ with the best response rate was the skin (46%), followed by gastrointestinal tract (43%), liver (41%), the oral mucosa (36%), eyes (29%), and lungs (18%). Imatinib led to steroid tapering in 17/38 patients. Twenty-five (38%) patients experienced imatinib-related adverse events, comprising extra-hematologic toxicity (n = 24, 36%) and hematologic toxicity (n = 6, 9%). No cases of grade 4-5 toxicity were reported. The main causes of imatinib discontinuation were treatment failure (52%) and toxicity (9%). After a median follow-up of 41 months, the 3-year overall survival was 81%, with no difference between imatinib responders and non-responders. These real-life results show that imatinib is safe and has moderate efficacy in patients with heavily pre-treated cutaneous sclerotic cGVHD; however, activity against lung cGVHD is very limited.

Nilotinib Treatment of Patients Affected by Chronic Graft-versus-Host Disease Reduces Collagen Production and Skin Fibrosis by Downmodulating the TGF-β and p-SMAD Pathway

The present study was conducted to investigate cellular and molecular features of chronic graft-versus-host disease fibroblasts (GVHD-Fbs) and to assess the effectiveness of nilotinib as a fibrosis modulator. Growth kinetics, phenotype, and differentiation of cultured skin biopsy-derived GVHD-Fbs were compared with normal fibroblasts from both a dermal cell line (n-Fbs) and healthy individuals undergoing cosmetic surgery (n-skin-Fbs). Collagen genes (COL1α1/COL1α2) and p-SMAD2 expression were assessed by real-time PCR and immunofluorescence. The in vivo effects of nilotinib on chronic GVHD (cGVHD)-affected skin were investigated by immunohistochemistry; the relationship to TGF-β plasma levels was assessed. Although the morphology, phenotype, and differentiation of cultured GVHD-Fbs were comparable to normal fibroblasts, growth was slower and senescence was reached earlier. The expression of COL1α1 and COL1α2 mRNAs was respectively 4 and 1.6 times higher in cGVHD-Fbs (P = .02); the addition of TGF-β increased n-Fbs, but not GVHD-Fbs, collagen gene expression. Compared with the baseline, the addition of 1 μM nilotinib induced 86.5% and 49% reduction in COL1α1 and COL1α2 expression in cultured GVHD-Fbs, respectively (P< .01). In vivo immunohistochemistry analysis of skin biopsy specimens from patients with cGVHD showed strong baseline staining for COL1α1 and COL1α2, which decreased sharply after 180 days of nilotinib; immunofluorescence revealed TGF-β inhibition and p-Smad2 reduction at the intracellular level. Of note, nilotinib treatment was associated with normalization of TGF-β levels both in culture supernatants and in plasma. In general, the data show that cGVHD fibroblasts promote fibrosis through abnormal collagen production induced by hyperactive TGF-β signaling. TGF-β inhibition at the intracellular and systemic level represents an essential antifibrotic mechanism of nilotinib in a clinical setting.

The concurrent administration of imatinib with extracorporeal photopheresis leads to complete and durable responses in patients with refractory sclerotic type chronic graft-versus-host disease

Therapeutic options are limited for patients developing refractory sclerotic-type chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic cell transplantation. We previously showed that imatinib mesylate (IM) could be efficacious in this situation, although complete responses were uncommon (Magro L Blood 2009). We hypothesized that the combination of extracorporeal photopheresis (ECP) and IM could have synergistic effects to treat SR steroid-refractory cGVHD. While IM and ECP are separately used for the treatment of refractory cGVHD, the combination of both has never been investigated. We describe here the efficacy of the concurrent administration of IM with ECP in seven patients with refractory sclerotic-type cGVHD who had showed insufficient response to either IM or ECP. Seven consecutive patients (3 males and 4 females) with a median age of 46 years old, who received imatinib with concurrent ECP for refractory sclerotic-type cGVHD, were included. Patients were considered refractory if they were steroid-refractory or steroid-dependent. Four patients had previously showed insufficient partial response (PR) to IM, while three patients showed insufficient PR while receiving ECP. IM was started at 200 mg/day and increased to 400 mg/day if well-tolerated. ECP was initiated twice weekly then less frequently according to the patient's individual treatment response. With a median follow-up of 56 months, the concurrent administration of IM with ECP deepened responses in all patients and induced durable complete responses (CR) in 4 (57%). Median time to best response was 4 months. Median duration of combination treatment was 42 months (range: 4-60). As of February 2018, 5 patients were still alive. Two patients died of myocardial infarction and one from relapse of a preexisting prostate cancer. The concurrent administration of IM with ECP led to complete and sustained responses in patients with refractory sclerotic-type cGVHD.

The Role of Co-stimulatory/Co-inhibitory Signals in Graft-vs.-Host Disease

Allogeneic hematopoietic cell transplantation (allo-HCT) is an effective immunotherapeutic approach for various hematologic and immunologic ailments. Despite the beneficial impact of allo-HCT, its adverse effects cause severe health concerns. After transplantation, recognition of host cells as foreign entities by donor T cells induces graft-vs.-host disease (GVHD). Activation, proliferation and trafficking of donor T cells to target organs and tissues are critical steps in the pathogenesis of GVHD. T cell activation is a synergistic process of T cell receptor (TCR) recognition of major histocompatibility complex (MHC)-anchored antigen and co-stimulatory/co-inhibitory signaling in the presence of cytokines. Most of the currently used therapeutic regimens for GVHD are based on inhibiting the allogeneic T cell response or T-cell depletion (TCD). However, the immunosuppressive drugs and TCD hamper the therapeutic potential of allo-HCT, resulting in attenuated graft-vs.-leukemia (GVL) effect as well as increased vulnerability to infection. In view of the drawback of overbroad immunosuppression, co-stimulatory, and co-inhibitory molecules are plausible targets for selective modulation of T cell activation and function that can improve the effectiveness of allo-HCT. Therefore, this review collates existing knowledge of T cell co-stimulation and co-inhibition with current research that may have the potential to provide novel approaches to cure GVHD without sacrificing the beneficial effects of allo-HCT.

Atopic Dermatitis-like Graft-versus-host Disease and Lichen Planus-like Graft-versus-host Disease: Alterations in Skin Barrier Function and Related Molecules

Background:

Graft-versus-host disease (GVHD) is a common complication of hematopoietic stem cell transplantation. Skin barrier disruption could induce thymic stromal lymphopoietin (TSLP) expression, and the expression of TSLP was increased in lesions of atopic dermatitis (AD)-like GVHD and lichen planus (LP)-like GVHD. This study attempted to investigate the skin barrier function of AD-like GVHD and LP-like GVHD and possible mechanisms.

Methods:

Eighteen AD-like GVHD patients, 12 LP-like GVHD patients, and 14 healthy volunteers were enrolled in this study. Skin biopsy was done in five AD-like GVHD patients, eight LP-like GVHD patients, and eight healthy volunteers. The intensity of pruritus was assessed by visual analog scale itch score and detailed pruritus score. Transepidermal water loss (TEWL) was measured using Tewameter^® TM 300. Immunohistochemistry was used to observe the expression of loricrin, involucrin, LL37, and human β-defensins 2 (hBD2) in skin lesions. Western blot analysis was used for analyzing the protein levels of loricrin and involucrin in skin lesions. Real-time polymerase chain reaction was performed to assess the mRNA levels of LL37 and hBD2 in skin lesions.

Results:

Pruritus score was higher in patients with AD-like GVHD (11.33 ± 5.35) than that of patients with LP-like GVHD (2.58 ± 3.09, P < 0.001). Compared with healthy controls (HCs, 4.52 ± 1.24 g·m⁻²·h⁻¹), TEWL was increased in AD-like GVHD (26.72 ± 9.02 g·m⁻²·h⁻¹, P < 0.001) and LP-like GVHD patients (18.78 ± 4.57 g·m⁻²·h⁻¹, P < 0.001), and expressions of loricrin and involucrin were also increased in skin lesions of AD-like GVHD and LP-like GVHD patients (all P < 0.05). LL37 mRNA expression was decreased in lesions of AD-like GVHD and LP-like GVHD patients (P = 0.005 and P = 0.008, vs. HCs, respectively). hBD2 mRNA expression was increased in skin lesions of AD-like GVHD and LP-like GVHD patients (P = 0.002 and P < 0.001, vs. HCs, respectively).

Conclusions:

Skin barrier dysfunction is present in AD-like GVHD and LP-like GVHD. The immunoreactions, but not the congenital defect, are considered to be the primary cause of skin barrier impairment in AD-like GVHD and LP-like GVHD.

Immunomodulatory Effects of Tyrosine Kinase Inhibitor In Vitro and In Vivo Study

Pathogenesis of chronic graft-versus-host disease (cGVHD) is incompletely defined, involving donor-derived CD4 and CD8-positive T lymphocytes as well as B cells. Standard treatment is lacking for steroid-dependent/refractory cases; therefore, the potential usefulness of tyrosine kinase inhibitors (TKIs) has been suggested, based on their potent antifibrotic effect. However, TKIs seem to have pleiotropic activity. We sought to evaluate the in vitro and in vivo impact of different TKIs on lymphocyte phenotype and function. Peripheral blood mononuclear cells (PBMCs) from healthy donors were cultured in the presence of increasing concentrations of nilotinib, imatinib, dasatinib, and ponatinib; in parallel, 44 PBMC samples from 15 patients with steroid-dependent/refractory cGVHD treated with nilotinib in the setting of a phase I/II trial were analyzed at baseline, after 90, and after 180 days of therapy. Flow cytometry was performed after labeling lymphocytes with a panel of monoclonal antibodies (CD3, CD4, CD16, CD56, CD25, CD19, CD45RA, FoxP3, CD127, and 7-amino actinomycin D). Cytokine production was assessed in supernatants of purified CD3⁺ T cells and in plasma samples from nilotinib-treated patients. Main T lymphocyte subpopulations were not significantly affected by therapeutic concentrations of TKIs in vitro, whereas proinflammatory cytokine (in particular, IL-2, IFN-γ, tumor necrosis factor-α, and IL-10) and IL-17 production showed a sharp decline. Frequency of T regulatory, B, and natural killer (NK) cells decreased progressively in presence of therapeutic concentrations of all TKIs tested in vitro, except for nilotinib, which showed little effect on these subsets. Of note, naive T regulatory cell (Treg) subset accumulated after exposure to TKIs. Results obtained in vivo on nilotinib-treated patients were largely comparable, both on lymphocyte subset kinetics and on cytokine production by CD3-positive cells. This study underlines the anti-inflammatory and immunomodulatory effects of TKIs and supports their potential usefulness as treatment for patients with steroid-dependent/refractory cGVHD. In addition, both in vitro and in vivo data point out that compared with other TKIs, nilotinib could better preserve the integrity of some important regulatory subsets, such as Treg and NK cells.

The Role of B Cell Targeting in Chronic Graft-Versus-Host Disease

Chronic graft-versus-host disease (cGVHD) is a leading cause of late morbidity and mortality following allogeneic stem cell transplantation. Current therapies, including corticosteroids and calcineurin inhibitors, are only effective in roughly 50% of cases; therefore, new treatment strategies are under investigation. What was previously felt to be a T cell disease has more recently been shown to involve activation of both T and B cells, as well as a number of cytokines. With a better understanding of its pathophysiology have come more expansive preclinical and clinical trials, many focused on B cell signaling. This report briefly reviews our current understanding of cGVHD pathophysiology and reviews clinical and preclinical trials with B cell-targeted agents.

Chronic graft-versus-host disease presenting as eosinophilic fasciitis: therapeutic challenges and an additional case

Chronic graft-versus-host disease (cGVHD) is one of the main late complications of allogeneic hematopoietic stem cell transplant and a major contributor to the mortality and morbidity in surviving recipients. Skin is the most common involved organ in cGVHD and may mimic a wide spectrum of dermatological conditions in its clinical and histopathologic manifestations. Some of the commonly simulated diseases are scleroderma, morphea, and lichen sclerosus. Chronic GVHD simulating eosinophilic fasciitis (EF) is relatively rare, frequently presenting with skin induration, a typical "peau d'orange" appearance, peripheral blood eosinophilia, myalgia, arthralgia, and arthritis leading to joint contractures in severe cases.Diagnosis is based on clinical manifestations and histopathology. Treatment is challenging because most cases are refractory to first-line therapy of glucocorticoids and calcineurin inhibitors (CNIs), and there is no standard second-line therapy.We report a comprehensive review of literature on all reported cases of CGVHD presenting as EF. We also describe an additional interesting case of cGVHD presenting as EF that was resistant to traditional therapy of high-dose glucocorticoids and cyclosporin A, but showed complete resolution of skin manifestations after addition of imatinib.Chronic GVHD presenting as EF is a rare variant of sclerodermatous cGVHD. Diagnosis is difficult, and treatment of cGVHD mimicking EF remains a therapeutic challenge because of obscure pathogenesis and poor response to traditional immunosuppressive medications. Emerging insights into the pathogenesis of cGVHD have resulted in the development of novel targeted therapies, which may improve outcomes and should be attempted in this subset of the disease. Larger studies are warranted to substantiate these preliminary findings.

Therapeutic benefits targeting B-cells in chronic graft-versus-host disease

Allogeneic hematopoietic cell transplantation (allo-HCT) can be a curative strategy for hematological diseases, and the indications for allo-HCT have broadened widely due to recent progress in supportive strategies. However, patients must overcome various complications and chronic graft-versus-host disease (cGVHD) remains the most common allo-HCT cause of long-term morbidity and mortality. cGVHD is difficult to biologically assess due to the heterogeneity of cGVHD symptoms, and the pathogenesis of cGVHD has yet to be established. Recent experimental model progress has suggested that B-cells play a critical role in cGVHD development. Consistent with these experimental results, some clinical studies investigating B-cell depletion and modulation of B-cell signaling pathways have decreased cGVHD incidence and provided some therapeutic benefit. However, randomized control studies are necessary to confirm the efficacy of B-cell targeting drugs for cGVHD. Here, we review the pathophysiology of cGVHD, especially focusing on the role of B-cell immunity, and discuss the efficacy of both B-cell depletion and modulation of B-cell signaling pathways in human cGVHD prevention, initial treatment, and salvage treatment.

Imatinib: a breakthrough of targeted therapy in cancer

Deregulated protein tyrosine kinase activity is central to the pathogenesis of human cancers. Targeted therapy in the form of selective tyrosine kinase inhibitors (TKIs) has transformed the approach to management of various cancers and represents a therapeutic breakthrough. Imatinib was one of the first cancer therapies to show the potential for such targeted action. Imatinib, an oral targeted therapy, inhibits tyrosine kinases specifically BCR-ABL, c-KIT, and PDGFRA. Apart from its remarkable success in CML and GIST, Imatinib benefits various other tumors caused by Imatinib-specific abnormalities of PDGFR and c-KIT. Imatinib has also been proven to be effective in steroid-refractory chronic graft-versus-host disease because of its anti-PDGFR action. This paper is a comprehensive review of the role of Imatinib in oncology.

Long-term outcome and prospective validation of NIH response criteria in 39 patients receiving imatinib for steroid-refractory chronic GVHD

Efficacy of imatinib in steroid-refractory chronic GVHD was prospectively compared across 3 different response systems, with high agreement. Validity of quantitative-based assessment of response with NIH criteria was confirmed by its prognostic impact on long-term survival.

Is Imatinib Maintenance Required for Patients with Relapse Chronic Myeloid Leukemia Post-Transplantation Obtaining CMR? A Pilot Retrospective Investigation

Imatinib can induce complete molecular remission (CMR) in relapse chronic myelogenous leukemia (CML) after allogeneic hematopoietic stem cell transplantation, but it is indefinite whether imatinib is required to maintain CMR. We retrospectively reviewed 37 relapse CML post-transplants treated with imatinib (n = 20) or donor lymphocyte infusion (DLI) (n = 17). The rate of CMR was 85% and 76.47% (P = 0.509) and treatment-related mortality was 0% and 29.4% (P = 0.019), respectively, in imatinib and DLI groups. Fifteen patients obtaining CMR voluntarily ceased imatinib, and did not experience relapse. The 8-year overall survival (OS) after relapse was 85%±8% and 40.3±12.1% (P = 0.017), and disease-free survival (DFS) after relapse was 85%±8% and 40.3±12.1% (P = 0.011), respectively, in imatinib and DLI groups. Imatinib resulted in higher OS and DFS than that of DLI in relapse CML. Imatinib maintenance might not be required for patients with relapse CML post-transplants after they achieved full donor chimerism and CMR.

Pharmacology and rationale for imatinib in the treatment of scleroderma

Systemic sclerosis (scleroderma) is a chronic, multisystem, fibrotic disease. Although the pathogenesis is not completely understood, early vascular damage leads to an inflammatory reaction and a severe fibrotic response. Therapy of systemic sclerosis is still not convincing and is mainly restricted to the management of organ complications. A wide choice of immunosuppressive and antifibrotic drugs has been used to try to modify the course of the disease, but significant breakthroughs are still lacking. Imatinib is a tyrosine kinase inhibitor known to regulate growth, proliferation, and differentiation as well as apoptosis of cells and is already widely used for several malignancies, eg, chronic myeloid leukemia and gastrointestinal stromal tumors. It has been used in preclinical as well as clinical studies to modulate the fibrotic process in patients with systemic sclerosis. This is based on its activity to interfere selectively with both the transforming growth factor-β and platelet-derived growth factor signaling pathway. Preclinical studies in mouse models of scleroderma showed significant anti-inflammatory and antifibrotic effects; however, several clinical, proof-of-concept trials have not yet confirmed these initially promising results.