Autoimmune Polyendocrine Syndrome Type Research Articles

Single cell characterization of blood and expanded regulatory T cells in autoimmune polyendocrine syndrome type 1

Immune tolerance fails in autoimmune polyendocrine syndrome type 1 (APS-1) because of AIRE mutations. We have used single cell transcriptomics to characterize regulatory Tcells (Tregs) sorted directly from blood and from invitro expanded Tregs in APS-1 patients compared to healthy controls. We revealed only CD52 and LTB (down) and TXNIP (up) as consistently differentially expressed genes in the datasets. There were furthermore no large differences of the TCR-repertoire of expanded Tregs between the cohorts, but unique patients showed a more restricted use of specific clonotypes. We also found that invitro expanded Tregs from APS-1 patients had similar suppressive capacity as controls in co-culture assays, despite expanding faster and having more exhausted cells. Our results suggest that APS-1 patients do not have intrinsic defects in their Treg functionality, and that their Tregs can be expanded exvivo for potential therapeutic applications.

Autoimmune polyendocrine syndrome type 1 in an 11-year- old boy

Autoimmune polyendocrine syndrome type 1 is a rare autosomal recessive hereditary pathology — a defect in the autoimmune regulator gene (AIRE), which develops with endocrine and non-endocrine manifestations in childhood. The disease is characterized by clinical polymorphism, which makes timely diagnosis difficult. The article describes a clinical case of an 11-year-old patient with autoimmune polyendocrine syndrome type 1, in whom the course of the disease was erased for a long period. The high quality of life of such patients is possible with timely, individually selected substitution therapy, followed by dispensary observation.

Early recognition of the APECED rash can accelerate the diagnosis of APECED

Autoimmune-Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED) is a monogenic autoimmune disease most often resulting from biallelic loss-of-function variants in the autoimmune regulator (AIRE) gene. Although typically characterized by the classic triad of chronic mucocutaneous candidiasis, hypoparathyroidism, and adrenal insufficiency, we have recently reported that the clinical spectrum of the syndrome is far broader that previously described and that incorporation of an adjunct triad of APECED rash, autoimmune enteritis-associated intestinal dysfunction, and enamel hypoplasia in the classic triad manifestations could lead to earlier diagnosis. Among the adjunct triad manifestations, APECED rash occurs in 66 % of American APECED patients by age 3, most often developing in the first year of life. Here, we describe the clinical and histological features of protracted APECED rash manifesting together with recurrent mucocutaneous candidiasis as the first two disease components of APECED in a 10-month-old girl.

Challenges and pitfalls in the management of endocrine toxicities from immune checkpoint inhibitors: a case presentation of synchronous thyrotoxicosis and primary adrenal insufficiency in a melanoma patient.

Immune checkpoint inhibitors have revolutionized the therapeutic approach to several solid tumors, becoming the standard of care for cancer treatment in different disease settings. Despite the fact that these agents are better tolerated than conventional chemotherapy, their use is associated with a specific toxicity profile, so-called immune-related adverse events (irAEs), that can involve several organs. Endocrine irAEs are among the most frequent toxicities (around 10 to 16%) and include hypophysitis, thyroid disorders, adrenalitis, and diabetes mellitus. Some of them may be life-threatening if not promptly recognized (such as diabetic ketoacidosis and acute adrenal crisis). A 55-year-old woman with a personal history of euthyroid Hashimoto's thyroiditis was diagnosed with a metastatic melanoma, BRAF wild type. Under treatment with anti-PD-1 pembrolizumab, she developed thyrotoxicosis followed by hypothyroidism due to destructive thyroiditis and concurrent primary adrenal insufficiency due to adrenalitis. The simultaneous occurrence of adrenal and thyroid autoimmune diseases, resembling autoimmune polyendocrine syndrome type 2, may occur as a rare but serious side effect of ICI treatment. It often presents with abrupt onset and rapid evolution towards polyglandular insufficiency. Physicians should be aware of the potential association of two or more endocrine disorders and careful monitoring of endocrine function is needed during ICI therapy.

Schmidt's Syndrome: An Uncommon Cause of Spontaneous Hypoglycemia

AbstractSchmidt's syndrome, or autoimmune polyendocrine syndrome type 2 (APS-2), is an uncommon disorder characterized by the co-occurrence of autoimmune thyroiditis and adrenalitis. APS-2 is defined as a combination of Addison's disease, autoimmune thyroid disease, and/or type 1 diabetes mellitus. It is an autosomal dominantly inherited polygenic disorder with incomplete penetrance; the candidate genes include but are not limited to HLA-DR3, HLA-DR4, CTLA-4, PTPN22, and CD25-IL-2. Autoimmune thyroiditis, often Hashimoto's disease, results in hypothyroidism. Primary adrenal failure results in enhanced secretion of adrenocorticotrophic hormone melanocyte and co-secretion of melanocyte-stimulating hormone, contributing to hyperpigmentation. Mineralocorticoid deficiency results in salt wasting, fatigue and cramps, postural hypotension, and hyperkalemia. Cortisol, an insulin counter-regulatory hormone, plays a pivotal role in maintaining euglycemia; deficiency predisposes to the development of hypoglycemia. We here report a rare presentation of Schmidt's syndrome as hypoinsulinemic hypoglycemia in a middle-aged male patient. Management includes treatment of acute hypoglycemic episodes with glucose or glucagon, long-term glucocorticoids and mineralocorticoids for adrenal insufficiency, and thyroid hormone supplements for hypothyroidism. This case report and brief overview aim to contribute to the scientific understanding of Schmidt's syndrome/APS-2. Additionally, here we briefly outline the diagnostic challenges in hypoglycemia evaluation, including the utilization of Whipple's triad and the gold standard supervised 72-hour fast and evaluation for primary adrenal and thyroid insufficiencies.

Increased type 1 inflammation in gynecologic cervicovaginal samples in patients with APS-1

Inborn errors of immunity offer important insights into mucosal immunity. In autoimmune polyendocrine syndrome type-1 (APS-1), chronic mucocutaneous candidiasis has been ascribed to neutralizing IL-17 autoantibodies. Recent evidence implicates excessive T-cell IFN-γ secretion and ensuing epithelial barrier disruption in predisposition to candidiasis, but these results remain to be replicated. Whether IL-17 paucity, increased type I inflammation, or their combination underlies susceptibility to chronic mucocutaneus candidiasis in APS-1 is debated. Our aim was to characterize the immunologic features in the cervicovaginal mucosa of females with APS-1. Vaginal fluid was collected with a flocked swab from 17 females with APS-1 and 18 controls, and cytokine composition was analyzed using Luminex (Luminex Corporation, Austin, Tex). Cervical cell samples were obtained with a cervix brush from 6 patients and 6 healthy controls and subjected to transcriptome analysis. The vaginal fluid samples from patients with APS-1 had IFN-γ concentrations comparable to those of the controls (2.6 vs 2.4 pg/mL) but high concentrations of the TH1 chemokines CXCL9 and CXCL10 (1094 vs 110 pg/mL [P< .001] and 4033 vs 273 pg/mL [P= .001], respectively), whereas the IL-17 levels in the samples from the 2 groups were comparable (28 vs 8.8 pg/mL). RNA sequencing of the cervical cells revealed upregulation of pathways related to mucosal inflammation and cell death in the patients with APS-1. Excessive TH1 cell response appears to underlie disruption of the mucosal immune responses in the genital tract of patients with APS-1 and may contribute to susceptibility to candidiasis in the genital tract as well.

Cutaneous Manifestations in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED): A Comprehensive Review.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), or polyglandular autoimmune syndrome type 1 (PAS-1/APS-1), is a rare autosomal recessive disorder linked to mutations in the autoimmune regulator (AIRE) gene. This review provides a detailed analysis of cutaneous manifestations in APECED, focusing on chronic mucocutaneous candidiasis (CMC), alopecia areata (AA), and vitiligo. The classic triad of hypoparathyroidism, adrenal insufficiency, and CMC serves as a diagnostic cornerstone. However, the varied clinical spectrum of APECED, particularly its cutaneous presentations, poses a diagnostic challenge. CMC, often an early sign, varies in prevalence across populations, including Finnish (100%), Irish (100%), Saudi Arabian (80%), Italian (60-74.7%), North American (51-86%), and Croatian (57.1%) populations. Similarly, AA prevalence varies in different populations. Vitiligo also exhibits variable prevalence across regions. The review synthesizes the current knowledge arising from a narrative analysis of 14 significant human studies published in English up to October 2023. Moreover, this paper underscores the importance of early detection and monitoring, emphasizing cutaneous manifestations as key diagnostic indicators. Ongoing research and clinical vigilance are crucial for unraveling the complexities of this rare autoimmune syndrome and enhancing patient care.

Novel Insights into the Autoimmunity from the Genetic Approach of the Human Disease.

Autoimmune-polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a monogenic inborn error of autoimmunity that is caused by damaging germline variants in the AIRE gene and clinically manifests with multiple autoimmune diseases in patients. Studies on the function of the AIRE gene, discovered in 1997, have contributed to fundamental aspects of human immunology as they have been important in understanding the basic mechanism of immune balance between self and non-self. This chapter looks back to the discovery of the AIRE gene, reviews its main properties, and discusses the key findings of its function in the thymus. However, more recent autoantibody profilings in APECED patients have highlighted a gap in our knowledge of the disease pathology and point to the need to revisit the current paradigm of AIRE function. The chapter reviews these new findings in APECED patients, which potentially trigger new thoughts on the mechanism of immune tolerance.

Identification of unstable regulatory and autoreactive effector T cells that are expanded in patients with FOXP3 mutations.

Studies of the monogenic autoimmune disease immunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX) have elucidated the essential function of the transcription factor FOXP3 and thymic-derived regulatory T cells (Tregs) in controlling peripheral tolerance. However, the presence and the source of autoreactive T cells in IPEX remain undetermined. Here, we investigated how FOXP3 deficiency affects the T cell receptor (TCR) repertoire and Treg stability in vivo and compared T cell abnormalities in patients with IPEX with those in patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy syndrome (APECED). To study Tregs independently of their phenotype and to analyze T cell autoreactivity, we combined Treg-specific demethylation region analyses, single-cell multiomic profiling, and bulk TCR sequencing. We found that patients with IPEX, unlike patients with APECED, have expanded autoreactive T cells originating from both autoreactive effector T cells (Teffs) and Tregs. In addition, a fraction of the expanded Tregs from patients with IPEX lost their phenotypic and functional markers, including CD25 and FOXP3. Functional experiments with CRISPR-Cas9-mediated FOXP3 knockout Tregs and Tregs from patients with IPEX indicated that the patients' Tregs gain a TH2-skewed Teff-like function, which is consistent with immune dysregulation observed in these patients. Analyses of FOXP3 mutation-carrier mothers and a patient with IPEX after hematopoietic stem cell transplantation indicated that Tregs expressing nonmutated FOXP3 prevent the accumulation of autoreactive Teffs and unstable Tregs. These findings could be directly used for diagnostic and prognostic purposes and for monitoring the effects of immunomodulatory treatments.

Ruxolitinib Rescues Multiorgan Clinical Autoimmunity in Patients with APS-1

Autoimmune polyendocrine syndrome type-1 (APS-1) is caused by mono- or biallelic loss-of-function variants of the autoimmune regulator gene AIRE underlying early-onset multiorgan autoimmunity and the production of neutralizing autoantibodies against cytokines, accounting for mucosal candidiasis and viral diseases. Medical intervention is essential to prevent or attenuate autoimmune manifestations. Ruxolitinib is a JAK inhibitor approved for use in several autoimmune conditions. It is also used off-label to treat autoimmune manifestations of a growing range of inborn errors of immunity. We treated three APS-1 patients with ruxolitinib and followed them for at least 30 months. Tolerance was excellent, with no medical or biological adverse events. All three patients had remarkably positive responses to ruxolitinib for alopecia, nail dystrophy, keratitis, mucosal candidiasis, steroid-dependent autoimmune hepatitis, exocrine pancreatic insufficiency, renal potassium wasting, hypoparathyroidism, and diabetes insipidus. JAK inhibitors were therefore considered an effective treatment in three patients with APS-1. Our observations suggest that JAK/STAT pathways are involved in the pathogenesis of APS-1 autoimmune manifestations. They also suggest that JAK inhibitors should be tested in a broader range of APS-1 patients.

Dysregulated germinal center reaction with expanded T follicular helper cells in autoimmune polyendocrinopathy–candidiasis–ectodermal dystrophy lymph nodes

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, also called APS-1) is an inborn error of immunity with clear signs of B-cell autoimmunity such as neutralizing anti-IFN antibodies. In APECED, mutations in the AIRE gene impair thymic negative selection of T cells. The resulting T-cell alterations may then cause dysregulation of B-cell responses. However, no analysis of interactions of T and B cells in the germinal centers (GCs) in patients' secondary lymphatic tissues has been reported. This study examined the relationship between B cells and follicular T helper cells (TfH) in peripheral blood and lymph node (LN) GCs in patients with APECED. Immunophenotyping of peripheral blood B cells and TfH was performed for 24 patients with APECED. Highly multiplexed fluorescent immunohistochemical staining was performed on 7 LN biopsy samples from the patients to study spatial interactions of lymphocytes in the GCs at the single-cell level. The patients' peripheral B-cell phenotype revealed skewing toward a mature B-cell phenotype with marked loss of transitional and naive B cells. The frequency of circulating TfH cells was diminished in the patients, while in the LNs the TfH population was expanded. In LNs the overall frequency of Treg cells and interactions of Treg cells with nonfollicular T cells were reduced, suggesting that aberrant Treg cell function might fail to restrain TfH differentiation. GC reactions are disrupted in APECED as a result of defective T-cell control.

Genetic Susceptibility to Fungal Infections.

Reports of fungal infections have increased over the past decades, making them a major threat to human health. In this study, we review the effects of genetic defects on susceptibility to fungal diseases. To identify all relevant literature, we searched Google Scholar, PubMed, and Scopus and profiled studies published between 2008 and 2021. The results of several studies conducted on this subject have shown the significant effects of genetic variations such as hyper-IgE syndrome, Autoimmune polyendocrinopathy candidiasis ectodermal dystrophy syndrome, dectin-1 deficiency, CARD9 mutations, STAT1 mutations, and IL17 mutationson the host immune system's response, which has an important impact on susceptibility to fungal infections. The underlying immune system-related genetic profile affects the susceptibility of individuals to different fungal infections; therefore, this subject should be further studied for better treatment of fungal diseases.

A partial form of AIRE deficiency underlies a mild form of autoimmune polyendocrine syndrome type 1.

Autoimmune polyendocrine syndrome type 1 (APS-1) is caused by mutations in the autoimmune regulator (AIRE) gene. Most patients present with severe chronic mucocutaneous candidiasis and organ-specific autoimmunity from early childhood, but the clinical picture is highly variable. AIRE is crucial for negative selection of T cells, and scrutiny of different patient mutations has previously highlighted many of its molecular mechanisms. In patients with a milder adult-onset phenotype sharing a mutation in the canonical donor splice site of intron 7 (c.879+1G>A), both the predicted altered splicing pattern with loss of exon 7 (AireEx7-/-) and normal full-length AIRE mRNA were found, indicating leaky rather than abolished mRNA splicing. Analysis of a corresponding mouse model demonstrated that the AireEx7-/- mutant had dramatically impaired transcriptional capacity of tissue-specific antigens in medullary thymic epithelial cells but still retained some ability to induce gene expression compared with the complete loss-of-function AireC313X-/- mutant. Our data illustrate an association between AIRE activity and the severity of autoimmune disease, with implications for more common autoimmune diseases associated with AIRE variants, such as primary adrenal insufficiency, pernicious anemia, type 1 diabetes, and rheumatoid arthritis.

Alopecia areata and occurrence of vitiligo and hypothyroidism in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy patients.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is an inherited disorder of immunity which leads to increased risk for mucocutaneous candidiasis and multiorgan autoimmune disease. While alopecia areata (AA) has been described in some patients with APECED, the extent and timing of AA is not well established and extent and timing of concomitant vitiligo and hypothyroidism has not been described. We evaluated an APECED cohort followed at the National Institutes of Health for the timing of development of associated diseases. We found AA occurred earlier in those with APECED than in the general population, was rarely the first sign of APECED, and the timing of AA onset did correlate with the timing of onset of vitiligo or hypothyroidism which also occurred at high rates and early age.

Autoimmune regulator (Aire) deficiency results in reduced memory CD8+ T cells after Listeria monocytogenes infection in a murine model.

Homozygous mutations in the autoimmune regulator (AIRE) gene that cripple thymic negative selection of autoreactive T cells result in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED). However, how AIRE regulates the T cell response against foreign pathogens is not well understood. Here, we observed comparable primary CD8+ T cells but a markedly reduced memory T cell population and protective function in Aire-/- mice compared with wild-type after infection with a strain of recombinant Listeria monocytogenes. In adoptive transfer models, exogenous congenic CD8+ T cells transferred into Aire-/- mice also showed a reduction in the memory T cell population, indicating an important role for extrathymic Aire-expressing cells in shaping or sustaining memory T cells. Moreover, using a bone marrow chimeric model, we found that Aire expressed in radioresistant cells plays an important role in maintaining the memory phenotype. These results provide important insights into the role of extrathymic Aire in the T cell response to infection.

Analysis of a series of Italian APECED patients with autoimmune hepatitis and gastro-enteropathies.

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a rare monogenic disease determined by biallelic mutations in AIRE gene, which encodes a transcription factor essential for central immune tolerance. Classic diagnosis is determined by the presence of two of the main APECED clinical diseases: chronic mucocutaneous candidiasis, chronic hypoparathyroidism, and Addison's disease. Non-endocrine autoimmunity, involving the liver, intestine, eyes, and kidneys, is generally reported in a minority of European patients, while American APECED patients have a higher tendency of developing organ-specific non-endocrine manifestations early in life. This observation led to the revision of the diagnostic criteria to permit earlier diagnosis based on the appearance of one classic triad symptom or one non-classical manifestation at a young age in the presence of IFNωAbs or AIRE mutations (Ferre-Lionakis criteria). We analyzed the clinical, genetic, and autoantibody (Ab) profiles in a series of 14 pediatric Italian APECED patients with gastrointestinal manifestations (seven male and seven female patients). Ten patients presented hepatitis (APECED-associated hepatitis (APAH)), while seven were affected by constipation, diarrhea, and malabsorption. Four patients had developed APAH before classic triad symptoms. Based on the age of appearance of non-endocrine manifestations including APAH and gastro-enteropathy, the Ferre-Lionakis criteria would have allowed an expedited diagnosis in 11/14 patients. Abs to tryptophan hydroxylase (TPHAb) and hepatic aromatic l-amino acid decarboxylase (AADC) were significantly associated with APECED patients of the present series. Abs to cP4501A2 were detectable in the serum of 4/8 patients with APAH, and Abs to cP4502A6 were detectable in 3/8 patients. AADC Abs tested positive in 5/7 patients, which is indicative of gastrointestinal dysfunction in APECED and TPHAb in 5/7 patients with gastrointestinal dysfunction. IFNAb was significantly associated with the syndrome. Although Ferre-Lionakis expanded criteria applied to the American cohorts of APECED patients would require validation in independent large cohorts of European patients, the results of this study emphasize the importance to evaluate the presence and the age of appearance of APAH and autoimmune enteropathy even in European cohorts for an earlier APECED diagnosis. An earlier APECED diagnosis would also allow the prevention of episodes of life-threatening hypocalcemic seizures and adrenal crisis, which are the main manifestations of undiagnosed APECED.

Fahr's syndrome as a manifestation of autoimmune polyendocrine syndrome-1 and its unusual association with neuromyelitis optica spectrum disorder.

Fahr's syndrome, also known as bilateral striopallidodendate calcinosis, is a rare inherited neurodegenerative illness characterized by abnormal calcium deposition in several areas of the brain, resulting in a wide range of neuropsychological symptoms. Fahr's syndrome, secondary to autoimmune polyendocrine syndrome type 1, which includes adrenal insufficiency and mucocutaneous candidiasis in addition to hypoparathyroidism, is exceedingly rare. No case report has been documented to date to show the co-occurrence of Fahr's syndrome and neuromyelitis optica spectrum disorder. Here, we discuss the case of a 30-year-old man with a previous history of seizures and symptoms of ectodermal dystrophy presented with seizures, left-sided hemiparesis, dysarthria, and other characteristics indicative of severe hypocalcemia. The neuroimaging findings strongly suggested Fahr's syndrome, with radiographic evidence of Neuromyelitis optica spectrum disorder as longitudinal extensive transverse myelitis in the cervical spinal cord, high titers of serum aquaporin-4 antibodies, and demyelinating neuropathy on nerve conduction studies. This distinct neuropsychological presentation and neuroimaging findings led to the diagnosis of Fahr's syndrome as a result of hypoparathyroidism caused by autoimmune polyendocrine syndrome type 1 with cooccurrence of neuromyelitis optica spectrum disorder. The patient's clinical symptoms improved considerably after he was treated based on a provisional diagnosis. The clinical importance of our case is significant for both neuropsychiatrists and endocrinologists, as autoimmune polyendocrine syndrome should be considered as the etiology of Fahr's syndrome. This case report also aims to report this unusual association of Neuromyelitis optica spectrum disorder with Fahr's syndrome to give the future prospective to know whether this association is incidental or there is a missing link between these two different disorders.

APECED and the place of AIRE in the puzzle of the immune network associated with autoimmunity.

In the last 20 years, discoveries about the autoimmune regulator (AIRE) protein and its critical role in immune tolerance have provided fundamental insights into understanding the molecular basis of autoimmunity. This review provides a comprehensive overview of the effect of AIRE on immunological tolerance and the characteristics of autoimmune diseases in Autoimmune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy (APECED), which is caused by biallelic AIRE mutations. A better understanding of the immunological mechanisms of AIRE deficiency may enlighten immune tolerance mechanisms and new diagnostic and treatment strategies for autoimmune diseases. Considering that not all clinical features of APECED are present in a given follow-up period, the diagnosis is not easy in a patient at the first visit. Longer follow-up and a multidisciplinary approach are essential for diagnosis. It is challenging to prevent endocrine and other organ damage compared with other diseases associated with multiple autoimmunities, such as FOXP3, LRBA, and CTLA4 deficiencies. Unfortunately, no curative therapy like haematopoietic stem cell transplantation or specific immunomodulation is present that is successful in the treatment.

Vaccination prevents severe COVID-19 outcome in patients with neutralizing type 1 interferon autoantibodies

A hallmark of patients with autoimmune polyendocrine syndrome type 1 (APS-1) is serological neutralizing autoantibodies against type 1 interferons (IFN-I). The presence of these antibodies has been associated with severe course of COVID-19. The aims of this study were to investigate SARS-CoV-2 vaccine tolerability and immune responses in a large cohort of patients with APS-1 (N= 33) and how these vaccinated patients coped with subsequent infections. We report that adult patients with APS-1 were able to mount adequate SARS-CoV-2 spike-specific antibody responses after vaccination and observed no signs of decreased tolerability. Compared with age- and gender-matched healthy controls, patients with APS-1 had considerably lower peak antibody responses resembling elderly persons, but antibody decline was more rapid in the elderly. We demonstrate that vaccination protected patients with APS-1 from severe illness when infected with SARS-CoV-2 virus, overriding the systemic danger of IFN-I autoantibodies observed in previous studies.

Immune checkpoint inhibitor therapy-induced autoimmune polyendocrine syndrome type II and Crohn’s disease: A case report

The development of immune checkpoint inhibitors (ICIs) has heralded a new era in cancer treatment, enabling the possibility of long-term survival in patients with metastatic disease. Unfortunately, ICIs are increasingly implicated in the development of autoimmune diseases. We present a man with squamous cell carcinoma of the oropharynx on a combination of teriprizumab, docetaxel, and cisplatin therapy who developed autoimmune polyendocrine syndrome type II (APS-2) including thyroiditis and type 1 diabetes mellitus and Crohn's disease (CD). He developed thirst, abdominal pain, and fatigue after two-week treatment with the protein 1 ligand inhibitor teriprizumab. Biochemistry confirmed APS-2 and thyrotoxicosis. He was commenced on an insulin infusion. However, his abdominal pain persisted. Follow-up surgery confirmed CD and his abdominal pain was relieved by mesalazine. He was continued on insulin and mesalazine therapy. Immunotherapy can affect all kinds of organs. When clinical symptoms cannot be explained by a single disease, clinicians should consider the possibility of multisystem damage.