Adoptive transfer of vitiligo after allogeneic bone marrow transplantation for non-Hodgkin's lymphoma

Risk of Subsequent Vitiligo in Transplant Recipients With Comorbid Graft-vs-Host Disease

Importance

Vitiligo is a multifactorial, depigmenting skin disorder characterized by selective loss of melanocytes. Large-scale studies are lacking to determine the risk of vitiligo in transplant recipients with graft-vs-host disease (GVHD).

Objective

To investigate the incidence rates and risk of vitiligo in patients who had received solid organ transplant (SOT) or hematopoietic stem cell transplant (HSCT) overall and by HSCT graft type and concomitant GVHD.

Design, Setting, and Participants

This population-based cohort study included data from the National Health Insurance Service database of Korea for patients aged 20 years or older who had received a transplant (SOT or HSCT) between January 2010 and December 2017, with follow-up until December 2019. A cohort of age- and sex-matched (1:5) control individuals who did not receive a transplant was included for comparison. Data were analyzed from July 2021 to December 2021.

Exposure

Transplant (SOT or HSCT) and GVHD.

Main Outcomes and Measures

The main outcome was risk of vitiligo, assessed using multivariable Cox proportional hazards regression analyses adjusting for potential confounding factors.

Results

The study included 23 829 patients who had undergone SOT or HSCT (62.78% male; mean [SD] age, 49.58 [11.59] years) and 119 145 age- and sex-matched controls. Patients who had undergone transplant had a significantly higher risk of vitiligo compared with controls (adjusted hazard ratio [AHR], 1.73; 95% CI, 1.35-2.22). Risk of vitiligo was also slightly higher in kidney transplant recipients and liver transplant recipients compared with the controls but was highest in HSCT recipients (AHR, 12.69; 95% CI, 5.11-31.50). Patients who had received allogeneic grafts (AHR, 14.43; 95% CI, 5.61-37.15), those who had received autologous grafts (AHR, 5.71; 95% CI, 1.20-3.18), those with comorbid GVHD (AHR, 24.09; 95% CI, 9.16-63.35), and those without GVHD (AHR, 8.21; 95% CI, 3.08-21.87) had a higher risk of vitiligo compared with controls.

Conclusion and Relevance

In this study, risk of vitiligo was significantly higher in transplant recipients, especially in HSCT recipients and those with allogeneic grafts or comorbid GVHD. These findings provide new insights into the association between the risk of vitiligo and transplant and GVHD. Clinicians should be aware of these risks, implementing a multidisciplinary approach for monitoring.

Autoimmune diseases after allogeneic stem cell transplantation: a clinician's guide and future outlook

INTRODUCTION

Autoimmune disease (AD) may occur after allogeneic hematopoietic stem cell transplantation (HSCT). The autoimmune mechanism seems to be related to an imbalance of the immune regulation effect of T-regulatory lymphocytes on autoreactive T-lymphocytes.

AREAS COVERED

ADs include hematological ADs (HADs) and nonhematologic ADs (NHADs) involving organs such as thyroid, peripheral and central nervous system, skin, liver, connective tissue, gastrointestinal tract, and kidney. To identify the risk factors for ADs, to report their clinical characteristics, and to discuss new approaches represent the areas covered in this review.

EXPERT OPINION

Some risk factors for HAD and NHAD are common and include nonmalignant diseases, young age, cord blood as a stem cell source, conditioning regimens without total body irradiation, alemtuzumab, antithymocyte globulin, T-cell-depleted transplant, some viral infection, mixed chimerism, and chronic Graft versus Host Disease. In NHADs, the detection of autoantibodies is more frequent and the transfer of autoimmunity from the donor to the recipient represents the pathogenetic mechanism responsible for these complications. New therapeutic approaches such as bortezomib, daratumumab, sirolimus, eculizumab, and eltrombopag appear to be promising in terms of better efficacy and reduced toxicity compared to traditional therapies. New horizons based on personalized therapies will allow us to improve the prognosis of AD.

Successful Anti-TNF-Alpha Therapy for Crohn's Disease After Allogeneic Stem Cell Transplantation: A Case Report

Graft-versus-host disease (GVHD) is a potentially life-threatening complication of allogeneic stem cell transplantation (Allo-SCT). Chronic GVHD, which typically presents more than 100 days after Allo-SCT, can resemble manifestations of autoimmune disease; however, there are only a few reports on the development of Crohn's disease (CD) after Allo-SCT. Here, we report a case of steroid-refractory CD after umbilical cord blood transplantation (CBT), which was dramatically improved with administration of anti-tumor necrosis factor-alpha (anti-TNF-alpha) antibodies. A 21-year-old woman with refractory Hodgkin lymphoma underwent CBT and achieved complete remission. About 1 year after CBT, she complained of intermittent abdominal pain and bloody diarrhea, and colonoscopy revealed multiple longitudinal colonic ulcers with a cobblestone appearance; thus, based on the colonoscopy findings, she was diagnosed with CD. We considered a CD-like manifestation of gastrointestinal GVHD and initially administered steroids, but the therapeutic effect was poor. Then, we administered anti-TNF-alpha antibodies, infliximab, and then adalimumab, which resulted in rapid improvement of abdominal symptoms, with no recurrence despite discontinuation of this therapy. Anti-TNF-alpha antibodies are effective for CD after Allo-SCT, which can be considered as a subsequent complication of GVHD.

Vitiligo following stem-cell transplant

Vitiligo is an acquired skin disorder characterised by depigmentation of skin due to the selective destruction of melanocytes. The pathogenesis of vitiligo is still relatively unknown, but associations between vitiligo and other systemic autoimmune diseases have been made, such as with patients who have undergone haematopoietic stem cell transplantation (HSCT) in the treatment of haematological conditions. This article aims to review published literature that have reported the incidence of vitiligo following HSCT in order to understand their relationship, and any potential connections between vitiligo and graft-versus-host disease (GVHD). On the 21st of May 2017, the databases Pubmed, EMBASE and SCOPUS were searched using the search terms Stem cell or transplant or GVHD AND vitiligo or leucoderma or leucoderma. There was a total of 38 cases (from 28 case report articles) along with 9 cohort studies that were included in the review. The studies reviewed showed that the incidence of vitiligo in patients who have received HSCT is higher than that of the normal population. Current studies are largely limited to single-case reports, which have certain inconsistencies with regard to patient/donor profiling, and future studies should look to address these issues.

Cellular and Molecular Mechanisms of Autoimmune Hepatitis

Autoimmune hepatitis is an uncommon idiopathic syndrome of immune-mediated destruction of hepatocytes, typically associated with autoantibodies. The disease etiology is incompletely understood but includes a clear association with human leukocyte antigen (HLA) variants and other non-HLA gene variants, female sex, and the environment. Pathologically, there is a CD4+ T cell-rich lymphocytic inflammatory infiltrate with variable hepatocyte necrosis and subsequent hepatic fibrosis. Attempts to understand pathogenesis are informed by several monogenetic syndromes that may include autoimmune liver injury, by several drug and environmental agents that have been identified as triggers in a minority of cases, by human studies that point toward a central role for CD4+ effector and regulatory T cells, and by animal models of the disease. Nonspecific immunosuppression is the current standard therapy. Further understanding of the disease's cellular and molecular mechanisms may assist in the design of better-targeted therapies, aid the limitation of adverse effects from therapy, and inform individualized risk assessment and prognostication.

High frequency of cutaneous manifestations including vitiligo and alopecia areata in a prospective cohort of patients with chronic graft-vs-host disease

Aim

To determine the frequency and the characteristics of cutaneous manifestations, especially vitiligo and alopecia areata, in patients with chronic graft-vs-host disease (cGVHD).

Methods

50 patients with cGVHD were prospectively enrolled in the observational study protocol and evaluated by an experienced dermatologist. The evaluation was focused on the clinical spectrum of skin and adnexal involvement, and the cutaneous GVHD score was determined according to National Institutes of Health (NIH) Consensus criteria. The presence of vitiligo, alopecia, xerosis, nail changes, and dyspigmentation was also assessed.

Results

Out of 50 cGVHD patients, 28 (56%) had skin involvement, and 27 of them (96%) had hypo and/or hyperpigmentations. 11 patients (39%) had a mild cutaneous NIH cGVHD score, 22% moderate, and 39% severe. 15 (30%) patients had nail changes and 10 (20%) had vitiligo or alopecia areata. Univariate analysis showed that patients with vitiligo/alopecia areata received more lines of prior systemic immunosuppressive therapy (P = 0.043), had lower Karnofsky performance status (P = 0.028), and had a higher B-cell number (P = 0.005), platelet count (P = 0.022), and total protein (P = 0.024). Vitiligo and alopecia areata were associated with higher NIH skin score (P = 0.001), higher intensity of immunosuppressive treatment (P = 0.020), and total body irradiation conditioning (P = 0.040). Multivariate regression model showed that patients with higher NIH skin scoring were 3.67 times more likely to have alopecia and/or vitiligo (odds ratio 3.67; 95% confidence interval 1.26-10.73), controlled for all other factors in the model (age at study entry, number of B-cells, platelet count, and global NIH score).

Conclusion

These data indicate that vitiligo and alopecia areata occur more frequently in cGVHD than previously reported.

Subsequent vitiligo after hematopoietic stem cell transplantation: A nationwide population-based cohort study from Korea

BACKGROUND

Subsequent vitiligo after hematopoietic stem cell transplantation (HSCT) has been described sporadically in case series.

OBJECTIVE

To investigate the incidence and risk factors of subsequent vitiligo after HSCT.

METHODS

A nationwide, population-based cohort study was performed using the Korean National Health Insurance Claims Database from 2009 to 2013. All HSCT recipients who had undergone HSCT between 2010 and 2011 and not treatment for vitiligo in 2009 (to exclude preexisting active vitiligo) were included in the HSCT recipient group, and an age- and sex-matched control group without HSCT was also established.

RESULTS

A total of 2747 HSCT recipients and 8241 controls were enrolled. Newly acquired vitiligo occurred in 1.06% of HSCT recipients between 2010 and 2013, and there was a significant increase (OR 3.130, 95% CI 1.859-5.271) in cases of vitiligo in HSCT recipients compared with controls (0.34%). Allogeneic HSCT (OR 5.593, 95% CI 1.628-19.213) and bone marrow-sourced stem cells (as compared with peripheral blood-sourced stem cells; OR 2.492, 95% CI 1.114-5.576) were independently associated with the development of vitiligo after HSCT.

LIMITATIONS

Medical record review was not available.

CONCLUSION

Vitiligo developed at a significantly increased rate after HSCT compared with controls. Allogeneic HSCT and bone marrow-sourced stem cells were independent risk factors.

Cellular stress and innate inflammation in organ-specific autoimmunity: lessons learned from vitiligo

For decades, research in autoimmunity has focused primarily on immune contributions to disease. Yet recent studies report elevated levels of reactive oxygen species and abnormal activation of the unfolded protein response in cells targeted by autoimmunity, implicating cellular stress originating from the target tissue as a contributing factor. A better understanding of this contribution may help to answer important lingering questions in organ-specific autoimmunity, as to what factors initiate disease and what directs its tissue specificity. Vitiligo, an autoimmune disease of the skin, has been the focus of translational research for over 30 years, and both melanocyte stress and immune mechanisms have been thought to be mutually exclusive explanations for pathogenesis. Chemical-induced vitiligo is a unique clinical presentation that reflects the importance of environmental influences on autoimmunity, provides insight into a new paradigm linking cell stress to the immune response, and serves as a template for other autoimmune diseases. In this review, I will discuss the evidence for cell stress contributions to a number of autoimmune diseases, the questions that remain, and how vitiligo, an underappreciated example of organ-specific autoimmunity, helps to answer them.

Risk factors and characterization of vitiligo and alopecia areata in patients with chronic graft-vs-host disease

IMPORTANCE

Cutaneous manifestations of chronic graft-vs-host disease (GvHD) are highly variable and may recapitulate well-characterized autoimmune diseases, including systemic sclerosis and Sjögren syndrome. However, vitiligo and alopecia areata (AA) have not been well characterized in the chronic GvHD setting.

OBJECTIVE

To determine laboratory markers, transplant-related factors, and other systemic manifestations associated with vitiligo and/or AA in patients with chronic GvHD.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional, retrospective study conducted by the National Institutes of Health (NIH) of 282 adult and pediatric patients with chronic GvHD seen under the NIH natural history protocol between 2004 and 2013.

MAIN OUTCOMES AND MEASURES

Demographic, clinical, and laboratory data, including measures of 11 antibodies, were included in the analysis. Patients with vitiligo and/or AA were identified from dermatologist documentation and photographic evidence. Univariate and multivariable logistic regression analyses were used to determine risk factors for vitiligo and AA development.

RESULTS

Fifteen (5.3%) of 282 patients demonstrated vitiligo (14 of 282; 4.9%) and/or AA (2 of 282; 0.7%) (1 patient had both vitiligo and AA). Univariate analysis identified female donor to male recipient sex mismatch (P = .003), positive test results for anticardiolipin (ACA) IgG (P = .03) or antiparietal antibody (P = .049), elevated CD19 level (P = .045), and normal or elevated IgG level (P = .02) as risk factors for vitiligo or AA. Female donor to male recipient sex mismatch (P = .003) and positive findings for ACA-IgG (P = .01) retained significance in the multivariable analysis.

CONCLUSIONS AND RELEVANCE

Female donor and female donor to male recipient sex mismatch, in particular, are significantly associated with the development of vitiligo and/or AA. Further studies are needed to explore transplant-related risk factors that may lead to better understanding of the pathomechanisms of chronic GvHD.

Halo naevi and café au lait macule regression in a renal transplant patient on immunosuppression

A case of halo naevi and café au lait macule regression in a renal transplant patient receiving long-term immunosuppressive therapy is described. We propose the direct transfer of an auto-reactive antibody, CD8 T-cells or tumour necrosis factor α from the transplant donor to the recipient as a possible cause. We have also considered insufficient immunosuppressive therapy as a possible mechanism.

Autoimmune polyglandular syndrome type II after bone marrow transplant: real transfer or acceleration of a programmed disease?

We report a case of autoimmune polyglandular syndrome type II that developed in an 11-year-old boy with homozygous sickle cell disease after allogeneic bone marrow transplant; the donor was his father, who was human leukocyte antigen identical and had vitiligo. On day 24 after transplant, the patient developed grade 1 acute graft-versus-host disease, which was controlled over a period of 3 months with corticosteroid-induced immunosuppression. Full donor engraftment was documented on day 31 after transplant, and this was further confirmed on days 59, 231, 321, 472, 549, and 720. Three months after transplant, the recipient developed adrenal insufficiency, and at 13 months, he developed vitiligo. Seventeen months after transplant, autoimmune thyroid disease, positive for thyroid peroxidase and thyroglobulin autoantibodies, was diagnosed. At the same time, we identified adrenal insufficiency in the donor. We analyzed a serum sample from the recipient for autoantibody markers for type 1 autoimmune diabetes mellitus. The sample was positive for antiglutamic acid decarboxylase. Antibody against 21-hydroxylase enzyme was also found (261 U/mL; normal value, < 1 U/mL). We conclude that the recipient developed autoimmune polyglandular syndrome type II after bone marrow transplant from his father, who was probably affected by the same syndrome.

[Vitiligo. What is new?]

Vitiligo occurs in Northern Europe in one of 200 people. The disease can cause significant psychological stress for the affected individual. These patients generate and accumulate massive amounts of H(2)O(2)- and peroxynitrite in the epidermal compartment. Consequently many proteins are oxidized or nitrated, leading in turn to partial or complete loss of functionality. Moreover, presence of DNA damage in the skin as well as in plasma has been shown, while apoptosis is not enhanced. Induction of DNA repair is associated with up-regulated functioning p53 protein. Considering possible genetic predisposition and /or spontaneous mutations, autoimmune reactions in the disease are put forward in the context of oxidative stress. In addition a review of recent and novel treatment modalities including the role of oxidative stress reduction and combined climatotherapy at the Dead Sea in a group are discussed.

The transfer of adaptive immunity to CMV during hematopoietic stem cell transplantation is dependent on the specificity and phenotype of CMV-specific T cells in the donor

The successful reconstitution of adaptive immunity to human cytomegalovirus (CMV) in hematopoietic stem cell transplantation (HSCT) recipients is central to the reduction of viral reactivation-related morbidity and mortality. Here, we characterized the magnitude, specificity, phenotype, function, and clonotypic composition of CMV-specific T-cell responses in 18 donor-recipient pairs both before and after HSCT. The principal findings were: (1) the specificity of CMV-specific T-cell responses in the recipient after HSCT mirrors that in the donor; (2) the maintenance of these targeting patterns reflects the transfer of epitope-specific T-cell clonotypes from donor to recipient; (3) less differentiated CD27(+)CD57(-) CMV-specific memory T cells are more likely to persist in the recipient after HSCT compared with more terminally differentiated CD27(-) CD57(+) CMV-specific memory T cells; (4) the presence of greater numbers of less differentiated CD8(+) CMV-specific T cells in the donor appears to confer protection against viral reactivation in the recipient after HSCT; and (5) CMV-specific T cells acquire a more differentiated phenotype and a restricted functional profile after HSCT. Overall, these findings define the immunologic factors that influence the successful adoptive transfer of antigen-specific T-cell immunity during HSCT, which enables the identification of recipients at particular risk of CMV reactivation after HSCT.

Possible transfer of vitiligo by allogeneic bone marrow transplantation: a case report

Among the cases yet published of development of vitiligo after BMT, only two can claim as possible adoptive transfer of such disease. We report a case of a patient with sickle cell disease in whom vitiligo developed after allogeneic BMT from his HLA identical father affected by vitiligo. We reviewed and searched for some particularities in the reported cases of post-BMT vitiligo.

Frontiers and controversies in the pathobiology of vitiligo: separating the wheat from the chaff

The pathogenesis of vitiligo is complex and not well understood. Genes play a role in all aspects of vitiligo pathogenesis, and studies are ongoing to identify these genes and understand their biology. There is a body of interlocking, compelling evidence supporting an autoimmune basis for most or all cases of generalized vitiligo. The development of an autoimmune disease generally involves three components; the immune system, environmental triggers and other exogenous precipitating factors, and the target tissue. In vitiligo, precipitating factors could induce melanocyte damage in genetically susceptible individuals and consequent cell death, loss of tolerance, and induction of melanocyte-directed autoimmunity. Future research will more precisely define the multiple biological events that regulate development of vitiligo.

Vitiligo following a combined liver-kidney transplant

We report an Afro-Caribbean male who developed vitiligo 10 days following a combined liver-kidney transplant from a Caucasian donor. Neither the donor nor the recipient had any previous history of vitiligo, nor of autoimmunity. The depigmentation gradually resolved by 8 weeks post-transplant with topical corticosteroids and standard maintenance immunosuppression. We propose that the skin depigmentation occurred due to the destruction of melanocytes by donor-derived alloreactive cytotoxic T-lymphocytes or antibody transferred during transplantation. Although vitiligo has been described in patients receiving allogeneic bone marrow transplantation for haematological malignancy, there are no previous reports of vitiligo post-solid organ transplantation.

Genetic differences in bone marrow-derived lymphoid lineages control susceptibility to experimental autoimmune myocarditis

Bone marrow (BM) transplantation has been used to study the cellular basis of genetic control of autoimmune diseases, but conclusions remain elusive due to the contradictory findings in different animal models. In the current study, we found that BM cells from myocarditis-susceptible A.SW mice can render irradiated, myocarditis-resistant B10.S recipient mice susceptible to myosin-induced myocarditis, indicating that hematopoietic cells express the genetic differences controlling susceptibility to autoimmune myocarditis. We then sought to differentiate the role of lymphoid vs nonlymphoid components of BM in the pathogenesis of myocarditis by comparing mixed chimeras receiving BM from A.SW wild-type or RAG(-/-) mice mixed with BM from B10.S wild-type mice. This experiment clearly demonstrated that T and B lymphocytes were indispensable for transferring the susceptible phenotype to disease-resistant recipients. Our findings significantly narrow the cellular expression of genetic polymorphisms controlling the EAM phenotype.

Vitiligo after hematopoietic cell transplantation: six cases and review of the literature

AIM

To investigate the prevalence and clinical characteristics of vitiligo after allogeneic hematopoietic cell transplantation (AHCT).

METHODS

The development of vitiligo was analyzed among 421 patients who underwent AHCT in Ibni Sina Hospital (University of Ankara) between 1988 and 2004.

RESULTS

Among 421 patients, we describe 6 with generalized vitiligo occurring after AHCT for chronic myelogenous leukemia. Five of them had severe chronic graft-versus-host disease (GVHD). Vitiligo was accompanied by alopecia areata and acquired ichthyosis in 2 patients with GVHD.

CONCLUSION

Melanocyte destruction caused by the autoimmune reactions triggered by chronic GVHD as well as a genetic predisposition might have played a role in the development of vitiligo in our patients. These data support the hypothesis that vitiligo is an autoimmune entity.

Vitiligo as a post-bone marrow transplantation complication

Vitiligo is an autoimmune condition in which T cells recognize and destroy melanocytes. We present a case of a 20-year-old male who developed generalized vitiligo 4 years after allogeneic bone marrow transplantation (BMT) for Fanconi anemia. Although other autoimmune conditions have been well characterized as post-BMT complications, vitiligo is very rare. We review the 9 previously reported cases of post-BMT vitiligo.

Cicatricial pemphigoid of the oropharynx after allogeneic stem cell transplantation for relapsed follicular lymphoma

A 44-year-old woman with refractory follicular lymphoma underwent allogeneic stem cell transplantation (SCT) and achieved complete remission. Grade III acute graft-versus-host disease (GVHD) developed on day 23, but no chronic GVHD occurred. The patient developed severe erosion with bullous lesions in the oral cavity 18 months after SCT. At that time, the lymphoma remained in complete remission, and she had no clinical or laboratory findings suggesting chronic GVHD. A biopsy of the oral mucosa showed moderate lymphoplasmacytic infiltration and subepidermal bullae, and direct immunofluorescence staining demonstrated linear deposition of C3 at the dermo-epidermal junction. An immunoblotting assay using human epidermal extracts confirmed the presence in her serum of an antibody against the 230-kd bullous pemphigoid antigen 1 (BPAG1). A diagnosis of cicatricial pemphigoid (CP) was made, and complete resolution of the CP was achieved with prednisolone therapy. The occurrence of autoimmune blistering diseases is rare after allogeneic SCT.

Physiopathology and genetics of vitiligo

Generalized vitiligo is an acquired disorder in which white patches of skin and overlying hair result from autoimmune loss of melanocytes from involved areas. The autoimmune pathogenesis of vitiligo has become a rapidly evolving field of research. A humoral immune reaction has been implicated through the detection of circulating antibodies. However, recent research focuses on a melanocyte-specific cytotoxic-T-cell immune reaction in the melanocyte destruction. Several candidate genes have been proposed for vitiligo susceptibility. They include genes important for melanin biosynthesis, response to oxidative stress and/or regulation of autoimmunity. A recent genome-wide scan performed on families with numerous members presenting vitiligo has clearly revealed linkage of susceptibility loci.

[Auto-immune-like disease post-bone marrow transplantation]

INTRODUCTION

Bone marrow transplantation (BMT) is based on destruction of the patient's bone marrow with rescue of haematopoietic stem cells from a donor. Chronic graft-vs-host disease (GVH) is the major complication post-BMT and mimics some autoimmune diseases, such as scleroderma, sicca syndrome, primary biliary cirrhosis and an increased prevalence of various autoantibodies. Other autoimmune-like manifestations have been reported as case reports or short series. The most common are myasthenia gravis, polymyositis, autoimmune cytopenias and Graves' disease or autoimmune hypothyroidism.

CURRENT KNOWLEDGE AND KEY POINTS

These diseases occur mainly in association with chronic GVH. The pathophysiology of chronic GVH and other autoimmune-like diseases post-BMT remains poorly understood. Different mechanisms have been postulated. Most of the autoimmune events (either chronic GVH or more specific diseases) seem to be related to a poor or inadequate immunologic recovery post-BMT with an imbalance between autoregulatory and autoreactive lymphocytes. Microchimerism and molecular mimicry have been recently evocated. A minority of cases (autoimmune thyroid disorders) is attributed to the direct transfer of autoreactive cells from donor to patient (adoptive immunity).

FUTURE PERSPECTIVES

Despite physiopathologic uncertainty, these autoimmune-like disorders post-BMT are an interesting model for primary autoimmune diseases.

Evidence for an autoimmune pathogenesis of vitiligo

Vitiligo is a depigmenting disorder characterized by the development of white patches in various distributions, which are due to the loss of melanocytes from the epidermis. A variety of arguments from clinical observations to research findings in human and animal models support the hypothesis of autoimmunity and are reviewed in this article. The association with autoimmune diseases and organ-specific autoantibodies is well known. Various effective treatment options have an immunosuppressive effect. Today the autoimmune pathogenesis of the disease has become a rapidly evolving field of research. Detection of circulating melanocyte antibodies in human and animal models implicates a possible role of humoral immunity. Histological and immunohistochemical studies in perilesional skin suggest the involvement of cellular immunity in vitiligo. Recently, T-cell analyses in peripheral blood further support this hypothesis. Interestingly, new insights in the association of vitiligo and melanoma may help to clarify the role of autoimmunity in the development of vitiligo.

Induction of tolerance in autoimmune diseases by hematopoietic stem cell transplantation: getting closer to a cure?

Hematopoietic stem cells (HSCs) are the earliest cells of the immune system, giving rise to B and T lymphocytes, monocytes, tissue macrophages, and dendritic cells. In animal models, adoptive transfer of HSCs, depending on circumstances, may cause, prevent, or cure autoimmune diseases. Clinical trials have reported early remission of otherwise refractory autoimmune disorders after either autologous or allogeneic hematopoietic stem cell transplantation (HSCT). By percentage of transplantations performed, autoimmune diseases are the most rapidly expanding indication for stem cell transplantation. Although numerous editorials or commentaries have been previously published, no prior review has focused on the immunology of transplantation tolerance or development of phase 3 autoimmune HSCT trials. Results from current trials suggest that mobilization of HSCs, conditioning regimen, eligibility and exclusion criteria, toxicity, outcome, source of stem cells, and posttransplantation follow-up need to be disease specific. HSCT-induced remission of an autoimmune disease allows for a prospective analysis of events involved in immune tolerance not available in cross-sectional studies.

Direct evidence to support the role of antigen-specific CD8(+) T cells in melanoma-associated vitiligo

Vitiligo is a cutaneous pigmentary disorder characterized by the loss of melanocytes. An autoimmune mechanism is strongly suspected to be involved in this affection given that it is frequently associated with autoimmune hormonal disorders, and because antibodies directed against melanocytic antigens are found in the serum of patients with vitiligo. We examined the role of cellular immunity in melanoma-associated vitiligo by expanding infiltrating lymphocytes from fresh biopsy specimens of vitiligo patches in melanoma patients. The vitiligo-infiltrating lymphocytes were almost exclusively T lymphocytes, and most were CD8(+). Following in vitro expansion, vitiligo-infiltrating lymphocytes remained predominantly CD8(+) and expressed the cutaneous homing receptor CLA. Furthermore, vitiligo-infiltrating lymphocytes had a clonal or oligoclonal T cell receptor profile, possibly reflecting specific antigenic stimulation. Finally, vitiligo- infiltrating lymphocytes specifically recognized differentiation antigens shared by normal melanocytes and melanoma cells. This direct demonstration of CD8(+) T cell involvement in vitiligo suggests that, in melanoma patients, vitiligo may be a visible effect of a spontaneous antitumoral immune response.

Generalized vitiligo after lymphocyte infusion for relapsed leukaemia

Vitiligo is an autoimmune disease caused by T-lymphocyte-mediated destruction of melanocytes. We describe two patients with generalized vitiligo caused iatrogenically after donor lymphocyte infusion (DLI) for leukaemia relapse over 3 years after bone marrow transplantation (BMT). Neither the sibling donor nor the recipient had vitiligo or other autoimmune diseases, and vitiligo did not occur after the first BMT. DLI was accompanied by skin graft-versus-host disease in both cases, which was controlled with immunosuppression. However, over several months, progressive generalized and persistent skin depigmentation occurred in both patients. Peripheral blood molecular studies showed the complete disappearance of host haematolymphopoiesis. The specific destruction of melanocytes in both patients was therefore probably mediated by new alloreactive lymphocytes infused from the donors.