Autoimmune disease after autologous hematopoietic stem cell transplantation

Severe autoimmune pancytopenia after autologous hematopoietic stem cell transplantation for Hodgkin lymphoma

Autoimmune pancytopenia is rarely seen with Hodgkin lymphoma, and only one pediatric case of pancytopenia after autologous hematopoietic stem cell transplantation (HSCT) has been reported. We herein report a case of autoimmune pancytopenia that developed after autologous HSCT for nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). A 56-year-old Japanese woman underwent autologous HSCT for NLPHL. She developed autoimmune pancytopenia seven months after autologous HSCT. In this case, PSL was effective, and the blood cell counts normalized completely. However, the patient suffered from a fatal infection, probably because of immunosuppression caused by prolonged administration of PSL, as well as a history of several chemotherapies and autologous HSCT. To our knowledge, this is the first adult case of autoimmune pancytopenia after autologous HSCT for Hodgkin lymphoma. To further validate the optimal treatment strategy for autoimmune cytopenia after autologous HSCT, more cases are necessary.

A review on the effect of prolyl isomerization on immune response aberration and hypersensitivity reactions: A unifying hypothesis

Little is known about the causes and mechanisms of ectopic immune responses, including different types of hypersensitivity, superantigens, and cytokine storms. Two of the most questionable phenomena observed in immunology are why the intensity and extent of immune responses to different antigens are different, and why some self-antigens are attacked as foreign. The secondary structure of the peptides involved in the immune system, such as the epitope-paratope interfaces plays a pivotal role in the resulting immune responses. Prolyl cis/trans isomerization plays a fundamental role in the form of the secondary structure and the folding of proteins. This review covers some of the emerging evidence indicating the impact of prolyl isomerization on protein conformation, aberration of immune responses, and the development of hypersensitivity reactions.

SARS-CoV-2 plays a pivotal role in inducing hyperthyroidism of Graves' disease

Coronavirus disease 2019 (COVID-19) advances to affect every part of the globe and remains a challenge to the human race. Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) was shown to affect many organs and organ systems including the thyroid gland as these parts highly express angiotensin-converting enzyme 2 (ACE2) protein, which functions as a receptor for initially entering the virus into the cells. Furthermore, some categories of the population including older people and persons with comorbidities are prone to be more vulnerable to COVID-19 and its complications. Recent reports showed that SARS-CoV-2 infection could cause Graves' disease (autoimmune hyperthyroidism) in post-COVID-19 patients. Factors that may boost the mortality risk of COVID-19 patients are not completely known yet and a clear perception of the group of vulnerable people is also essential. This review briefly summarizes the features of Graves' disease such as symptoms, risk factors, including environmental, genetic, immunological, and other factors, associated disorders, and therapeutic options. It comprehensively describes the recent advances in SARS-CoV-2-induced Graves' disease and the pivotal role of autoimmune factors in inducing the disease. The review also discusses the possible risks of SARS-CoV-2 infection and associated COVID-19 in people with hyperthyroidism. Furthermore, it explains thyroid disease and its association with the severity of COVID-19.

Secondary failure of platelet recovery in patients treated with high-dose thiotepa and busulfan followed by autologous stem cell transplantation

Autologous stem cell transplantation (ASCT) with high-dose thiotepa and busulfan is a treatment option for patients with central nervous system (CNS) lymphoma. We report here the occurrence of secondary failure of platelet recovery (SFPR) in three out of 24 patients who received high-dose thiotepa and busulfan followed by ASCT. Although there was no obvious abnormality in the primary platelet engraftment as well as the recovery of other blood cells, they developed SFPR with a median time to onset of day 38, and the platelets gradually recovered over several months with steroid therapy. During the same period, there was no development of SFPR among 50 patients who received ASCT with a conditioning regimen of MEAM (ranimustine, etoposide, cytarabine, and melphalan) or high-dose melphalan. However, one of the two patients who received a conditioning regimen of busulfan and melphalan developed SFPR, suggesting that the use of a busulfan-based conditioning regimen may be one of the risk factors for SFPR. It is important to be aware of this possible adverse effect of ASCT with high-dose thiotepa and busulfan to ensure timely diagnosis and prevention of subsequent serious complications.

Autoimmunity Following Allogeneic Hematopoietic Stem Cell Transplantation

Autoimmune manifestations after allogeneic hematopoietic stem cell transplantation (AHSCT) are rare and poorly understood due to the complex interplay between the reconstituting immune system and transplant-associated factors. While autoimmune manifestations following AHSCT have been observed in children with graft-versus-host disease (GvHD), an alloimmune process, they are distinct from the latter in that they are generally restricted to the hematopoietic compartment, i.e., autoimmune hemolytic anemia, thrombocytopenia, and/or neutropenia. Autoimmune cytopenias in the setting of ASHCT represent a donor against donor immune reaction. Non-hematologic autoimmune conditions in the post-AHSCT setting have been described and do not currently fall under the GvHD diagnostic criteria, but could represent alloimmunity since they arise from the donor immune attack on the antigens that are shared by the donor and host in the thyroid, peripheral and central nervous systems, integument, liver, and kidney. As in the non-transplant setting, autoimmune conditions are primarily antibody mediated. In this article we review the incidence, risk factors, potential pathophysiology, treatment, and prognosis of hematologic and non-hematologic autoimmune manifestations in children after AHSCT.

Adrenal crisis in a 14-year-old boy 12 years after hematopoietic stem cell transplantation

We report on a boy of Albanian descent with the history of juvenile myelomonocytic leukemia (JMML). JMML was diagnosed at the age of 17 months and treated by hematopoietic stem cell transplantation (HSCT). At the age of 14.3 years, about 12 years after HSCT, he was hospitalized with an adrenal crisis. Hormone findings were consistent with primary adrenal insufficiency. Autoimmune adrenalitis was confirmed by positive autoantibodies against 21-hydroxylase and adrenal tissue. Since autoimmune Hashimoto thyroiditis was already known from the age of 9 years, we assume that both diseases are part of the spectrum of autoimmune polyglandular syndrome (APS) type 2. APS type 2 is a rare endocrine disease characterized by Addison’s disease along with autoimmune thyroid disease and/or type 1 diabetes.

Hematopoietic stem cell transplantation in autoimmune disorders: From immune-regulatory processes to clinical implications

Autoimmune diseases are characterized by the development of autoreactive T- and B-cells targeting self-antigens, which eventually can result in chronic and persistent organ damage. The autologous hematopoietic stem cell transplantation (AHSCT) opened new avenues in the treatment of patients with severe, treatment-resistant autoimmune diseases. This paper reviews the immune-regulatory mechanisms behind AHSCT, and also summarizes the experiences of clinical practice related to the therapy in organ-specific and systemic autoimmune diseases. It seems that the intricate interplay of various immune competent cells with regulatory capacity control in a synergistic manner the repopulated immune system after AHSCT, which potentially leads to a significant clinical improvement in certain autoimmune diseases. However, the widespread use of AHSCT was intrinsically limited, due to the serious side-effects of conditioning treatment and relatively high treatment-related mortality; moreover, the development of new effective and safe therapeutic approaches and the dawn of biological agents further limited its indications in the last decade. Nevertheless, with an appropriate patient selection and increased experience of transplant centres, the risks can be minimized, and AHSCT remained still a reasonable choice in multiple sclerosis and systemic sclerosis when the conventional therapy failed and further progression of disease is inevitable.

Graft versus self (GvS) against T-cell autoantigens is a mechanism of graft-host interaction

Graft-versus-host disease (GVHD) represents the major nonrelapse complication of allogeneic hematopoietic cell transplantation. Although rare, the CNS and the eye can be affected. In this study, manifestation in the retina as part of the CNS and T-cell epitopes recognized by the allogeneic T cells were evaluated. In 2 of 6 patients with posttransplantation retina diseases and 6 of 22 patients without ocular symptoms, antigen-specific T-cell responses against retina-specific epitopes were observed. No genetic differences between donor and recipient could be identified indicating T-cell activation against self-antigens (graft versus self). Transplantation of a preexisting immunity and cross-reactivity with ubiquitous epitopes was excluded in family donors and healthy individuals. In summary, an immunological reaction against retina cells represents a mechanism of graft-versus-host interaction following hematopoietic cell transplantation.

Evans syndrome after autologous peripheral blood stem cell transplantation for recurrent Hodgkin lymphoma

There have been a number of recent reports on the occurrence of autoimmune conditions after autologous hematopoietic stem cell transplantation. We describe a rare case of Evans syndrome (ES) that developed in a 16-year-old patient >1 year after autologous peripheral blood stem cell transplantation for recurrent Hodgkin lymphoma. ES is a rare and frequently refractory condition. No therapy for the condition has been established, and it can often be fatal. In the present case, i.v. cyclosporine A injection was significantly effective against the ES, which has not recurred.

An update on stem cell transplantation in autoimmune rheumatologic disorders

Stem cell transplant (SCT) has long been the standard of care for several hematologic, immunodeficient, and oncologic disorders. Recently, SCT has become an increasingly utilized therapy for refractory autoimmune rheumatologic disorders (ARDs). The efficacy of SCT in ARDs has been attributed to resetting an aberrant immune system either through direct immune replacement with hematopoietic stem cells or through immunomodulation with mesenchymal stem cells. Among ARDs, refractory systemic sclerosis (SSc) and systemic lupus erythematosus (SLE) are the most common indications for SCT. SCT has also been used in refractory rheumatoid arthritis, inflammatory myopathies, antiphospholipid syndrome, granulomatosis with polyangiitis, and pediatric ARDs. Complete responses have been reported in approximately 30 % of patients in all disease categories. Transplant-related mortality, however, remains a concern. Future large multi-center prospective randomized clinical trials will help to better define the specific role of SCT in the treatment of patients with ARDs.

Delineating the autoimmune mechanisms in Graves' disease

The immunologic processes involved in autoimmune thyroid disease (AITD), particularly Graves' disease (GD), are similar to other autoimmune diseases with the emphasis on the antibodies as the most unique aspect. These characteristics include a lymphocytic infiltrate at the target organs, the presence of antigen-reactive T and B cells and antibodies, and the establishment of animal models of GD by antibody transfer or immunization with antigen. Similar to other autoimmune diseases, risk factors for GD include the presence of multiple susceptibility genes, including certain HLA alleles, and the TSHR gene itself. In addition, a variety of known risk factors and precipitators have been characterized including the influence of sex and sex hormones, pregnancy, stress, infection, iodine and other potential environmental factors. The pathogenesis of GD is likely the result of a breakdown in the tolerance mechanisms, both at central and peripheral levels. Different subsets of T and B cells together with their regulatory populations play important roles in the propagation and maintenance of the disease process. Understanding different mechanistic in the complex system biology interplay will help to identify unique factors contributing to the AITD pathogenesis.

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.

Muscle-specific kinase-antibody-positive myasthenia gravis after autologous bone marrow transplantation

A 44-year-old man presented with oculobulbar weakness approximately 5 years after autologous bone marrow transplantation (BMT). His workup led to the diagnosis of muscle-specific kinase-antibody-related myasthenia gravis (MG). There has been only one case report of muscle-specific kinase-antibody-positive MG after BMT, which was allogeneic. We report the first case of autologous BMT-associated MG with muscle-specific kinase antibody. The pathogenic mechanisms of immune dysregulation leading to MG after BMT are discussed.

Management of autoimmune diseases after haematopoietic stem cell transplantation

Autologous and allogeneic haematopoietic stem cell transplantation (HSCT) is an option for the treatment of malignant and non-malignant diseases, including the severe autoimmune diseases. Intriguingly, the 'new' autoimmunity developing after transplantation is a constantly recognized phenomenon, which has to be differentiated from original disease relapse, toxicity, infection and graft-versus-host disease. The reported autoimmune diseases occurring in this setting are mainly antibody-associated and organ-specific, with scarce evidence in support for specific treatment options. This review focuses on current concepts on the pathogenesis, the available data on incidence, risk factors, manifestations and treatment of post-HSCT autoimmune diseases.

Acute renal endothelial injury during marrow recovery in a cohort of combined kidney and bone marrow allografts

An idiopathic capillary leak syndrome ('engraftment syndrome') often occurs in recipients of hematopoietic cells, manifested clinically by transient azotemia and sometimes fever and fluid retention. Here, we report the renal pathology in 10 recipients of combined bone marrow and kidney allografts. Nine developed graft dysfunction on day 10-16 and renal biopsies showed marked acute tubular injury, with interstitial edema, hemorrhage and capillary congestion, with little or no interstitial infiltrate (≤10%) and marked glomerular and peritubular capillary (PTC) endothelial injury and loss by electron microscopy. Two had transient arterial endothelial inflammation; and 2 had C4d deposition. The cells in capillaries were primarily CD68(+) MPO(+) mononuclear cells and CD3(+) CD8(+) T cells, the latter with a high proliferative index (Ki67(+) ). B cells (CD20(+) ) and CD4(+) T cells were not detectable, and NK cells were rare. XY FISH showed that CD45(+) cells in PTCs were of recipient origin. Optimal treatment remains to be defined; two recovered without additional therapy, six were treated with anti-rejection regimens. Except for one patient, who later developed thrombotic microangiopathy and one with acute humoral rejection, all fully recovered within 2-4 weeks. Graft endothelium is the primary target of this process, attributable to as yet obscure mechanisms, arising during leukocyte recovery.

Rheumatologic manifestations of benign and malignant haematological disorders

Diseases of blood and lymphoreticular system can have multisystem manifestations. Rheumatologic involvement has been reported in association with many benign and malignant haematological disorders; these patients are equally likely to present to both clinical rheumatologists and haematologists. This review focuses on the well-described rheumatologic features, other occasionally reported rheumatologic manifestations and unusual musculoskeletal complications related to the treatment in patients with underlying haematological conditions. The aim of this review is to help increase the awareness of rheumatologic manifestations seen in the blood disorders and to highlight the potential diagnostic pitfalls.

Secondary autoimmune diseases occurring after HSCT for an autoimmune disease: a retrospective study of the EBMT Autoimmune Disease Working Party

To specify the incidence and risk factors for secondary autoimmune diseases (ADs) after HSCT for a primary AD, we retrospectively analyzed AD patients treated by HSCT reported to EBMT from 1995 to 2009 with at least 1 secondary AD (cases) and those without (controls). After autologous HSCT, 29 of 347 patients developed at least 1 secondary AD within 21.9 (0.6-49) months and after allogeneic HSCT, 3 of 16 patients. The observed secondary ADs included: autoimmune hemolytic anemia (n = 3), acquired hemophilia (n = 3), autoimmune thrombocytopenia (n = 3), antiphospholipid syndrome (n = 2), thyroiditis (n = 12), blocking thyroid-stimulating hormone receptor antibody (n = 1), Graves disease (n = 2), myasthenia gravis (n = 1), rheumatoid arthritis (n = 2), sarcoidosis (n = 2), vasculitis (n = 1), psoriasis (n = 1), and psoriatic arthritis (n = 1). After autologous HSCT for primary AD, the cumulative incidence of secondary AD was 9.8% ± 2% at 5 years. Lupus erythematosus as primary AD, and antithymocyte globulin use plus CD34(+) graft selection were important risk factors for secondary AD by multivariate analysis. With a median follow-up of 6.2 (0.54-11) years after autologous HSCT, 26 of 29 patients with secondary AD were alive, 2 died during their secondary AD (antiphospholipid syndrome, hemophilia), and 1 death was HSCT-related. This European multicenter study underlines the need for careful management and follow-up for secondary AD after HSCT.

Autologous hematopoietic stem cell transplantation in autoimmune diseases

The term 'autoimmune diseases' encompasses a spectrum of diseases whose clinical manifestations and, possibly, biological features vary widely. The results of conventional treatment are considered unsatisfactory in aggressive forms, with subsets of patients having short life expectancies. Relying on wide experimental evidence and more feeble clinical data, some research groups have used autologous hematopoietic stem cell transplantation (HSCT) in the most disabling autoimmune diseases with the aim of resetting the patient's immune system. Immunoablative conditioning regimens are preferred over their myeloablative counterparts, and some form of in vivo and/or ex vivo T-cell depletion is generally adopted. Despite 15 years' experience, published controlled clinical trials are still lacking, with the evidence so far available coming from pilot studies and registry surveys. In multiple sclerosis, clinical improvement, or at least lasting disease stabilization, can be achieved in the majority of the patients; nevertheless, the worst results are observed in patients with progressive disease, where no benefit can be expected from conventional therapy. Concerning rheumatologic diseases, wide experience has been acquired in systemic sclerosis, with long-term improvements in cutaneous disease being frequently reported, although visceral involvement remains unchanged at best. Autografting has proved to be barely effective in rheumatoid arthritis and quite toxic in juvenile idiopathic arthritis, whereas it leads to clinical remission and the reversal of visceral impairment in the majority of patients with systemic lupus erythematosus. A promising indication is Crohn's disease, in which long-term endoscopic remission is frequently observed. Growing experience with autologous HCST in autoimmune diseases has progressively reduced concerns about transplant-related mortality and secondary myelodysplasia/leukemia. Therefore, a sustained complete remission seems to be within the reach of autografting in some autoimmune diseases; in others, the indications, risks and benefits of autografting need to be better defined. Consequently, the search for new drugs should also be encouraged.

Undifferentiated spondyloarthritis following allogeneic stem cell transplantation

BACKGROUND

Stem cell transplant has been utilized in the treatment of malignancies and rheumatic disease. Rheumatic disease may be transferred from the donor with active disease or may be developed in a recipient de novo as a late complication of SCT.

CASE PRESENTATION

We here report the rare case of a 26-year old male patient, who has been diagnosed with undifferentiated spondyloarthropathy after unique circumstance. The patient suffered from intermittent inflammatory back pain and peripheral joint swelling for several years and did not find relief through multiple emergency room visits at different medical facilities. After a thorough history and physical exam, it was noted that our patient had developed signs of axial disease along with dactylitis and overall that he had been insidiously developing an undifferentiated spondyloarthopathy after allogeneic stem cell transplantation.

CONCLUSION

Our observation supports the hypothesis that de novo rheumatic disease can develop after stem cell transplant for a variety of reasons. Thus, larger studies and awareness of this association are needed to delineate the exact underlying mechanism(s).

Opportunistic autoimmune disorders: from immunotherapy to immune dysregulation

Rapid advances in our understanding of the immune network have led to treatment modalities for malignancies and autoimmune diseases based on modulation of the immune response. Yet therapeutic modulation has resulted in immune dysregulation and opportunistic autoimmune sequelae, despite prescreening efforts in clinical trials. This review focuses on recent clinical data on opportunistic autoimmune disorders arising from three immunotherapeutic modalities: (1) systemic immunomodulators, including interferon-alpha (also used to treat hepatitis C patients) and interferon-beta; (2) monoclonal antibodies to CTLA-4 and CD52, and (3) hematopoietic stem cell transplantation. Uncategorized predisposing factors in these patients include major histocompatibility complex and gender genetics, prevalence of different autoimmune diseases, prior chemotherapy, underlying disorder (e.g., hepatitis C), and preconditioning regimens as part of organ and stem cell transplants. Not unexpectedly, the prevalent autoimmune thyroid disease surfaced frequently. Our combination models to study the balance between thyroid autoimmunity and tumor immunity upon regulatory T-cell perturbation are briefly described.

Autologous stem cell transplantation in autoimmune and rheumatic diseases: from the molecular background to clinical applications

Autoimmune diseases have a multifactorial origin. Because of disturbances of the immune system, autoreactive T and B cells target self-antigens, leading to permanent organ damage. Despite novel therapeutic protocols, the disease course is chronic and in many instances the outcome is lethal. The efficacy of stem cell therapy has been observed in autoimmune animal models and in autoimmune diseases related to haematological abnormalities. Although the therapy is more than 30 years old, its broad spread has been delayed by the serious side-effects due to the conditioning treatments based on oncological protocols. Evaluation of the data of patients who have undergone autologous stem cell therapy reinforced the view that protocols used for conditioning treatments, mostly causing lymphoablation, and procedures carried out in specialist centres significantly reduced mortality, with an almost optimal therapeutical efficacy. New, multicentre investigations have been launched to compare the efficacy of various protocols. In this review, we summarize certain aspects of the molecular background of autologous stem cell transplantation and also depict the response to therapy in various autoimmune and rheumatic diseases.

Consideration of strategies for hematopoietic cell transplantation

Bone marrow transplantation has been adoptively transferred from oncology to the treatment of autoimmune disorders. Along with extension of prevalent transplant-related concepts, the assumed mechanism that arrests autoimmunity involves elimination of pathogenic cells and resetting of immune homeostasis. Similar to graft versus tumor (GVT) reactivity, allogeneic transplants are considered to provide a better platform of immunomodulation to induce a graft versus autoimmunity reaction (GVA). It is yet unclear whether recurrence of autoimmunity in both autologous and allogeneic settings reflects relapse of the disease, transplant-associated immune dysfunction or insufficient immune modulation. Possible causes of disease recurrence include reactivation of residual host pathogenic cells and persistence of memory cells, genetic predisposition to autoimmunity and pro-inflammatory characteristics of the target tissues. Most important, there is little evidence that autoimmune disorders are indeed abrogated by current transplant procedures, despite reinstitution of both peripheral and thymic immune homeostasis. It is postulated that non-specific immunosuppressive therapy that precedes and accompanies current bone marrow transplant strategies is detrimental to the active immune process that restores self-tolerance. This proposition refocuses the need to develop strategies of immunomodulation without immunosuppression.

[Immunoablation followed by autologous stem cell transplantation in lupus: a clinical update]

Systemic lupus erythematosus (SLE) is a classic systemic autoimmune disease. Standard treatment consists of chronic therapy with antimalarials, glucocorticoids and immunosuppressive/cytotoxic drugs, which is associated with considerable side effects. In contrast, immunoablation of autoreactive immunologic memory followed by autologous stem cell transplantation (ASCT) has been the only regimen capable of inducing long-term remission of up to 10 years after cessation of immunosuppressive therapy, even in severely affected patients. Introduced in 1996, the procedure has since been performed in 147 patients with severe SLE refractory to standard treatment in clinical studies worldwide. Most of these patients achieved clinical long-term remission. However, SLE relapses and secondary autoimmune disorders have been reported. Transplant-related mortality occurred in 6% of the 147 cases, with a wide center effect (2-13%). Here we summarise the results published in the literature on immunoablation followed by ASCT in SLE and discuss future perspectives for optimising this therapeutic approach. It may be possible to improve the outcome and reduce the risks of treatment by identifying patients with a poor prognosis at an early stage, before irreversible organ damage has taken place.

Mesenchymal stromal cells engineered to express erythropoietin induce anti-erythropoietin antibodies and anemia in allorecipients

Autologous bone marrow mesenchymal stromal cells (MSCs) have been successfully used for the delivery of erythropoietin (EPO) in murine models of anemia and myocardial infarction. For clinical applications where a transient effect would be adequate, such as myocardial infarction, the use of EPO-engineered universal donor allogeneic MSCs would be a substantial convenience. We thus investigated whether MSCs from C57BL/6 mice would permit robust transient EPO delivery in normal BALB/c allorecipients. Implantation of MSCs overexpressing murine EPO led to increases in hematocrit in syngeneic and allogeneic mice, but the latter eventually developed severe anemia due to acquired neutralizing anti-EPO antibodies. As MSCs constitutively produce the CCL2 chemokine which may behave as an adjuvant to the anti-EPO immune response, experiments were performed using EPO-engineered MSCs derived from CCL2(-/-) mice and similar results were obtained. In conclusion, MHC-mismatched MSCs can break the tolerance to autoantigens and lead to the development of pathogenic autoantibodies.