CD4+ T cells are essential for the development of destructive thyroiditis induced by anti-PD-1 antibody in thyroglobulin-immunized mice

PD-L1 expression in keratinocyte and infiltration of CD4 + T lymphocyte can predict a severe type of erythema multiforme major induced by the anti-PD-1 antibody, pembrolizumab

Skin toxicity is the most common adverse event of treatment with immune check point inhibitors. Among them, erythema multiforme is a rare occurrence with a frequency of 4%, with most of the cases developing grade 1/2 disease. We experienced high grade erythema multiforme major developing with pembrolizumab treatment for anal canal cancer with extensive skin metastases. Steroid ointment was ineffective, and the skin lesions with blisters expanded to > 45% of the body surface area. The patient was at risk for symptom aggravation, and a pulse therapy with methylprednisolone and increasing the dose of oral prednisolone (1 mg/kg) were started. The skin lesions improved in 1.8 months. Unless urgent and appropriate treatments such as high dose steroid administration were conducted, the skin toxicities could not be controlled. The presence of CD4+ T cells and PD-L1+ keratinocytes in the skin biopsy might be a predictive marker of erythema multiforme major resistant to standard steroid treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13691-024-00676-4.

Autoantibody-positivity before and seroconversion during treatment with anti-PD-1 is associated with immune-related adverse events in patients with melanoma

INTRODUCTION

Treatment with the immune checkpoint inhibitor anti-programmed cell death protein-1 (PD-1) often causes immune-related adverse events (irAEs). Since irAEs resemble autoimmune diseases, autoantibodies might play a role and could potentially be used to identify patients at risk. Therefore, we investigated the association between autoantibody-positivity and toxicity as well as clinical response in patients with melanoma treated with anti-PD-1.

MATERIALS AND METHODS

This two-center, retrospective study included 143 patients with melanoma treated with anti-PD-1. Toxicities grade ≥2 and recurrences/responses were captured until 6 months after treatment initiation. Autoantibody measurements were performed at baseline and 3 months after treatment initiation, including IgM-rheumatoid factor (RF), antinuclear antibodies (ANA), extractable nuclear antigen, anti-cyclic citrullinated peptide antibodies (anti-CCP2) and anti-thyroid antibodies.

RESULTS

169 irAEs were experienced by 86/143 patients (137 grades 1-2, 32 grades 3-4), the most common being thyroiditis (n=25), dermatitis (n=24), and sicca problems (n=19). Patients with autoantibodies at baseline experienced more irAEs (p=0.001), predominantly associated with anti-thyroid antibodies and thyroid dysfunction. No association was observed between any irAE and anti-CCP2, RF or ANA. In women, baseline and on-treatment anti-thyroid antibody-positivity as well as seroconversion during treatment was associated with thyroid dysfunction. In men, this association was only observed on-treatment. The presence of autoantibodies was not associated with melanoma recurrence (p=0.776) or response (p=0.597).

CONCLUSION

The presence of autoantibodies prior to anti-PD-1 therapy is associated with irAEs in patients with melanoma. Both baseline positivity and seroconversion of anti-thyroid antibodies were strongly associated with thyroid dysfunction. This association was stronger in women, with all women who were baseline positive developing thyroid dysfunction.

Targeting the aryl hydrocarbon receptor with FICZ regulates IL-2 and immune infiltration to alleviate Hashimoto's thyroiditis in mice

Hashimoto's thyroiditis (HT) is the most frequent autoimmune disorder. Growing work points to the involvement of aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor, in the regulation of immune homeostasis. However, the roles of AhR and its ligands in HT remains unclear. In this study, we leveraged public human database analyses to postulate that the AhR expression was predominantly in thyroid follicular cells, correlating significantly with the thyroid infiltration levels of multiple immune cells in HT patients. Using a thyroglobulin-induced HT mouse model and in vitro thyroid follicular epithelial cell cultures, we found a significant downregulation of AhR expression in thyrocytes both in vivo and in vitro. Conversely, activating AhR by FICZ, a natural AhR ligand, mitigated inflammation and apoptosis in thyrocytes in vitro and conferred protection against HT in mice. RNA sequencing (RNA-seq) of thyroid tissues indicated that AhR activation moderated HT-associated immune or inflammatory signatures. Further, immunoinfiltration analysis indicated that AhR activation regulated immune cell infiltration in the thyroid of HT mice, such as suppressing cytotoxic CD8+ T cell infiltration and promoting anti-inflammatory M2 macrophage polarization. Concomitantly, the expression levels of interleukin-2 (IL-2), a lymphokine that downregulates immune responses, were typically decreased in HT but restored upon AhR activation. In silico validation substantiated the binding interaction between AhR and IL-2. In conclusion, targeting the AhR with FICZ regulates IL-2 and immune infiltration to alleviate experimental HT, shedding new light on the therapeutic intervention of this prevalent disease.

Combined use of tyrosine kinase inhibitors with PD-(L)1 blockade increased the risk of thyroid dysfunction in PD-(L)1 blockade: a prospective study

BACKGROUND

Anti-programmed cell death-1 (ligand-1) antibody [PD-(L)1-Ab] can cause destructive thyroiditis and/or hypothyroidism. In addition, tyrosine kinase inhibitors (TKIs) frequently induce hypothyroidism. The aim of this prospective study is to examine the incidence and clinical characteristics of thyroid dysfunction induced by combination therapy of a PD-(L)1-Ab and TKI [PD-(L)1-Ab/TKI].

METHODS

A total of 757 patients treated with PD-(L)1-Ab or PD-(L)1-Ab/TKI were evaluated for anti-thyroid antibodies (ATAs) at baseline and for thyroid function for 48 weeks after treatment initiation and then observed until the last visit.

RESULTS

The cumulative incidences of destructive thyroiditis [4/23 (17.4%) vs. 45/734 (6.1%) patients, p < 0.001], isolated hypothyroidism [10/23 (43.5%) vs. 29/734 (4.0%) patients, p < 0.001], and all thyroid dysfunction [14/23 (60.9%) vs. 74/734 (10.1%) patients, p < 0.001] were significantly higher in the PD-(L)1-Ab/TKI group than PD-(L)1-Ab group, respectively. All patients positive for ATAs at baseline developed thyroid dysfunction after PD-(L)1-Ab/TKI treatment, a significantly higher incidence than that in those negative for ATAs at baseline [4/4 (100%) vs. 10/19 (52.6%) patients, p = 0.026].

CONCLUSIONS

The addition of TKIs increased the risk of thyroid dysfunction induced by PD-(L)1-Ab, with the risk being higher in patients positive for baseline ATAs.

Changes in TgAb and TPOAb titers are greater in thyrotoxicosis than isolated hypothyroidism induced by PD-1 blockade

Anti-thyroglobulin antibodies (TgAb) and/or anti-thyroid peroxidase antibodies (TPOAb) positivity at baseline is a risk marker for thyroid immune-related adverse events (thyroid-irAEs) in anti-programmed cell death-1 antibody (PD-1-Ab) treatment; however, it is unknown if TgAb and TPOAb titers are associated with clinical characteristics of thyroid-irAEs. Among 586 patients treated with PD-1-Ab at Nagoya University Hospital between 2 November 2015 and 30 September 2021, 57 patients developed thyroid-irAEs (thyrotoxicosis [n = 38]; hypothyroidism without prior thyrotoxicosis {isolated hypothyroidism} [n = 19]) in whom thyroid function, and TgAb and TPOAb titers were determined at baseline and at the onset. The changes in TgAb (median, 54.8 vs. 0.2 IU/mL; p = 0.002) and TPOAb titers (31.6 vs. 0 IU/mL; p = 0.032) from baseline to onset of developing thyroid-irAEs were greater in patients with thyrotoxicosis than patients with isolated hypothyroidism. Higher TgAb and TPOAb titers, and the TgAb titer at baseline were associated with an earlier onset of thyrotoxicosis and higher peak free thyroxine levels, respectively. Twenty-eight patients who developed hypothyroidism after thyrotoxicosis had higher TgAb (54.5 vs. 10.7 IU/mL; p = 0.011) and TPOAb titers at baseline (46.1 vs. 9.0 IU/mL; p < 0.001) and greater changes in TgAb (61.7 vs. 7.8 IU/mL; p = 0.025) and TPOAb titers (52.8 vs. -0.8 IU/mL; p < 0.001) than patients who did not develop hypothyroidism. The TgAb titer at baseline and changes in the TgAb and TPOAb titers were greater in patients with thyrotoxicosis than patients with isolated hypothyroidism, suggesting that the magnitude of the thyroid autoimmune response reflects the clinical types of thyroid-irAEs.

Single-cell profiling identifies IL1Bhi macrophages associated with inflammation in PD-1 inhibitor-induced inflammatory arthritis

Inflammatory arthritis (IA) is a common rheumatic adverse event following immune checkpoint inhibitors treatment. The clinical disparities between IA and rheumatoid arthritis (RA) imply disease heterogeneity and distinct mechanisms, which remain elusive. Here, we profile CD45+ cells from the peripheral blood or synovial fluid (SF) of patients with PD-1-induced IA (PD-1-IA) or RA using single-cell RNA sequencing. We report the predominant expansion of IL1Bhi myeloid cells with enhanced NLRP3 inflammasome activity, in both the SF and peripheral blood of PD-1-IA, but not RA. IL1Bhi macrophages in the SF of PD-1-IA shared similar inflammatory signatures and might originate from peripheral IL1Bhi monocytes. Exhausted CD8+ T cells (Texs) significantly accumulated in the SF of patients with PD-1-IA. IL1Bhi myeloid cells communicated with CD8+ Texs possibly via the CCR1-CCL5/CCL3 and CXCL10-CXCR3 axes. Collectively, these results demonstrate different cellular and molecular pathways in PD-1-IA and RA and highlight IL1Bhi macrophages as a possible therapeutic target in PD-1-IA.

Significance of the autoantibody assay in predicting the development of immune-related adverse events in patients receiving atezolizumab plus bevacizumab combination therapy for unresectable hepatocellular carcinoma

AIM

Atezolizumab plus bevacizumab (AB) combination therapy is the first-line treatment for unresectable hepatocellular carcinoma (u-HCC). The management of immune-related adverse events (irAEs) is an important issue associated with achieving a good therapeutic response in patients receiving AB therapy. However, few studies have reported irAE development in patients receiving AB therapy. This study focused on the association between irAE development and autoantibodies at baseline in patients receiving AB therapy.

METHODS

Sixty-one patients receiving AB therapy were enrolled. For autoantibodies, the following antibodies were tested before the start of AB therapy: antinuclear antibodies, rheumatoid factor (RF), anti-thyroglobulin antibodies, thyroid peroxidase antibodies, anti-thyroid stimulating hormone receptor antibodies, and acetylcholine receptor antibodies. A patient was considered to have pre-existing antibodies if any of the listed antibodies were present at baseline.

RESULTS

Ten patients (16%) developed irAEs during the observation period. The irAEs included liver injury, hypothyroidism, adrenal insufficiency, adrenocorticotropic hormone deficiency, and rhabdomyolysis. Patients with irAE (n = 10) were more likely to be positive for any autoantibody (hazard ratio [HR] 3.7, p = 0.047) and RF at baseline (HR 5.4, p = 0.035) and to achieve complete response (HR 5.8, p = 0.027) than those without. The presence of autoantibodies at baseline was an independent factor associated with irAE development.

CONCLUSION

In the real world, 16% of patients receiving AB therapy for u-HCC developed irAEs. Patients with autoantibodies at baseline are at high risk of developing irAEs and require cautious follow-up.

Establishment of immune suppression by cancer cells in the tumor microenvironment

With the clinical success of immune checkpoint inhibitors (ICIs), cancer immunotherapy has become an important pillar of cancer treatment in various types of cancer. However, more than half of patients fail to respond to ICIs, even in combination, uncovering a limited window of clinical responses. Therefore, it is essential to develop more effective cancer immunotherapies and to define biomarkers for stratifying responders and nonresponders by exploring the immunological landscape in the tumor microenvironment (TME). It has become clear that differences in immune responses in the TME determine the clinical efficacy of cancer immunotherapies. Additionally, gene alterations in cancer cells contribute to the development of the immunological landscape, particularly immune suppression in the TME. Therefore, integrated analyses of immunological and genomic assays are key for understanding diverse immune suppressive mechanisms in the TME. Developing novel strategies to control immune suppression in the TME from the perspective of immunology and the cancer genome is crucial for effective cancer immunotherapy (immune-genome precision medicine).

Thyroid dysfunction induced by anti-PD-1 therapy is associated with a better progression-free survival in patients with advanced carcinoma

PURPOSE

Thyroid dysfunction is the most common immune-related adverse event during anti-programmed cell death 1 (anti-PD-1) therapy. In this study, we monitored patients with advanced malignant tumors who received anti-PD-1 therapy to observe the characteristic of anti-PD-1 therapy-induced thyroid dysfunction and its correlation with prognosis.

METHODS

Patients with advanced carcinoma treated with anti-PD-1 therapy were evaluated for thyroid function at baseline and after treatment initiation from August 2020 to March 2022. Seventy-three patients were finally included in the study.

RESULTS

Among these patients, 19 (26.03%) developed thyroid dysfunction after receiving anti-PD-1 therapy. Primary hypothyroidism and thyrotoxicosis were the most common clinical manifestation. Anti-PD-1-induced thyroid dysfunction occurred 63 (26-131) days after administration; thyrotoxicosis appeared earlier than primary hypothyroidism. In Kaplan-Meier survival analysis, the progression-free survival (PFS) of the thyroid dysfunction group was better than that of the no thyroid dysfunction group (227 (95% confidence interval (CI) 50.85-403.15) days vs 164 (95% CI 77.76-250.24) days, p = 0.026). Male patients had better PFS than female patients (213 (95% CI 157.74-268.26) days vs 74 (95% CI 41.23-106.77) days, p = 0.031). In cox proportional hazards regression model, anti-PD-1-induced thyroid dysfunction remained an independent predictor of better PFS (hazard ratio (HR) = 0.339(0.136-0.848), p = 0.021).

CONCLUSION

Thyroid dysfunction is a common immune-related adverse events in advanced cancer patients treated with anti-PD-1 therapy and predicts a better prognosis.

TRIAL REGISTRATION

This study was retrospectively registered with Trial ClinicalTrials.gov (NCT05593744) on October 25, 2022.

Toxicity-specific peripheral blood T and B cell dynamics in anti-PD-1 and combined immune checkpoint inhibition

Immune checkpoint inhibitors (ICI) have revolutionized the treatment landscape of advanced malignancies, but come with a diverse spectrum of immune-related adverse events (irAEs). Mechanistic studies can aid the transition from expert-opinion to evidence-based irAE treatment strategies. We aimed to longitudinally characterize peripheral blood T and B cell dynamics in ICI-treated patients by multicolor flow cytometry and serum multiplex immunoassay at baseline, ± 3 weeks and ± 6 weeks or upon clinically relevant irAEs. We analyzed samples from 44 ICI-treated patients (24 anti-PD-1 monotherapy, 20 combined anti-PD-1/anti-CTLA-4; cICI), of whom 21 developed irAEs, and 10 healthy donors. IrAEs after cICI were characterized by significantly enhanced proliferation of Th1-associated, mainly (CD4+) CD27- effector memory T cells, as well as Th17-associated immune responses and germinal center activation (reflected by CXCL13 and IL-21 increases). We observed no changes in CD21lo, memory, class-switched or newly activated B cell subsets. Particularly double-positive PD-1+LAG-3+ CD8+ T cells showed enhanced cytotoxic capacity in patients with irAEs after cICI. Within anti-PD-1 monotherapy, irAEs were associated with modestly enhanced Th1-associated responses reflected by increased serum CXCL9 and CXCL10. In conclusion, ICI-induced toxicity is dominated by enhanced Th1-associated responses, but in cICI we also found evidence for Th17-associated responses and germinal center activation. Together, our data add to the growing body of evidence that irAEs may be driven by newly activated CD4+ helper T cells, specifically after cICI. This study also supports tailored irAE treatment, based on ICI regimen, and to deploy specific strategies such as Th17 inhibition especially in cICI-associated irAEs.

Predictors of thyroid adverse events during cancer immunotherapy: a real-life experience at a single center

BACKGROUND

Thyroid dysfunction is among the most common immune-related adverse events (irAEs) of immune checkpoint inhibitors (ICIs) therapy. Data regarding potential predictors of the development of thyroid irAEs are still limited and sometimes conflicting.

PATIENTS AND METHODS

We assessed potential risk factors and clinical outcomes associated with the onset of thyroid irAEs in a cohort of patients with different types of cancer treated with ICIs at a single center. Clinical and biochemical data, including thyroid function tests and autoantibodies at baseline and during treatment, were collected, and the onset of thyroid irAEs was recorded. Patients with thyroid dysfunction and/or under levothyroxine therapy before starting ICI were excluded.

RESULTS

110 patients (80 M, 30 F, aged 32-85 years; 56.4% non-small-cell lung cancer, 87% treated with anti-PD-1) with complete information were included in the study. Among them, 32 (29%) developed thyroid irAEs during ICIs therapy. Primary hypothyroidism was the most common irAEs, occurring in 31 patients (28.18% of the whole cohort), including 14 patients who experienced a transient thyrotoxicosis. About 60% of irAEs occurred within the first 8 weeks of therapy. At multivariate analysis, anti-thyroid autoantibodies positivity at baseline (OR 18.471, p = 0.022), a pre-existing (autoimmune and non-autoimmune) thyroid disorder (OR 16.307, p < 0.001), and a family history of thyroid diseases (OR = 9.287, p = 0.002) were independent predictors of the development of thyroid irAEs.

CONCLUSION

Our data confirm the high frequency of thyroid dysfunctions (mostly hypothyroidism) during ICIs, and provide data on valuable predictors of thyroid toxicities that may help clinicians in identifying patients at risk for developing irAEs.

Risk of Thyroid Dysfunction in PD-1 Blockade Is Stratified by the Pattern of TgAb and TPOAb Positivity at Baseline

CONTEXT

Positive antithyroglobulin (TgAb) and/or antithyroid peroxidase antibodies (TPOAb) at baseline indicate a high risk of thyroid immune-related adverse events (irAEs) induced by antiprogrammed cell death-1 antibodies (anti-PD-1-Ab). However, whether the positivity patterns of both antibodies are associated with the risk of thyroid irAEs is unknown.

OBJECTIVE

The aim of the present study was to clarify the association of the pattern of TgAb and TPOAb positivity at baseline with the risk of thyroid irAEs induced by anti-PD-1-Ab.

METHODS

Patients (n = 516) were evaluated for TgAb and TPOAb at baseline and prospectively for thyroid function every 6 weeks for 24 weeks after initiating anti-PD-1-Ab.

RESULTS

Fifty-one (9.9%) patients developed thyroid irAEs (thyrotoxicosis in 34, hypothyroidism without prior thyrotoxicosis in 17). Twenty-five patients subsequently developed hypothyroidism following thyrotoxicosis. The cumulative incidence of thyroid irAEs differed among 4 groups classified by the presence of TgAb/TPOAb at baseline (group 1: TgAb-(-)/TPOAb-(-), 4.6% [19/415]; group 2: TgAb-(-)/TPOAb-(+), 15.8% [9/57]; group 3: TgAb-(+)/TPOAb-(-), 42.1% [8/19]; group 4: TgAb-(+)/TPOAb-(+), 60.0% [15/25]) as follows: groups 1 vs 2-4 (P ≤ .001) and groups 2 vs 3 (P = .008) and 4 (P < .001). There were different incidences of thyrotoxicosis (groups 1-4, 3.1%, 5.3%, 31.6%, 48.0%, respectively; P < .001) in groups 1 vs 3 and 4, and groups 2 vs 3 and 4, and of hypothyroidism (groups 1-4: 2.9%, 15.8%, 31.6%, 60.0%, respectively; P < .001) in groups 1 vs 2 to 4, and groups 2 vs 4.

CONCLUSION

The risk of thyroid irAEs was affected by the pattern of TgAb and TPOAb positivity at baseline; there were high risks of thyrotoxicosis in patients with TgAb-(+) and of hypothyroidism in patients with TgAb-(+) and those with TPOAb-(+).

Stocking the toolbox-Using preclinical models to understand the development and treatment of immune checkpoint inhibitor-induced immune-related adverse events

Cancer patients treated with immune checkpoint inhibitors (ICIs) are susceptible to a broad and variable array of immune-related adverse events (irAEs). With increasing clinical use of ICIs, defining the mechanism for irAE development is more critical than ever. However, it currently remains challenging to predict when these irAEs occur and which organ may be affected, and for many of the more severe irAEs, inaccessibility to the tissue site hampers mechanistic insight. This lack of understanding of irAE development in the clinical setting emphasizes the need for greater use of preclinical models that allow for improved prediction of biomarkers for ICI-initiated irAEs or that validate treatment options that inhibit irAEs without hampering the anti-tumor immune response. Here, we discuss the utility of preclinical models, ranging from exploring databases to in vivo animal models, focusing on where they are most useful and where they could be improved.

CD4 T cells and toxicity from immune checkpoint blockade

Immune-related toxicities, otherwise known as immune-related adverse events (irAEs), occur in a substantial fraction of cancer patients treated with immune checkpoint inhibitors (ICIs). Ranging from asymptomatic to life-threatening, ICI-induced irAEs can result in hospital admission, high-dose corticosteroid treatment, ICI discontinuation, and in some cases, death. A deeper understanding of the factors underpinning severe irAE development will be essential for improved irAE prediction and prevention, toward maximizing the benefits and safety profiles of ICIs. In recent work, we applied mass cytometry, single-cell RNA sequencing, single-cell V(D)J sequencing, bulk RNA sequencing, and bulk T-cell receptor (TCR) sequencing to identify pretreatment determinants of severe irAE development in patients with advanced melanoma. Across 71 patients separated into three cohorts, we found that two baseline features in circulation-elevated activated CD4 effector memory T-cell abundance and TCR diversity-are associated with severe irAE development, independent of the affected organ system within 3 months of ICI treatment initiation. Here, we provide an extended perspective on this work, synthesize and discuss related literature, and summarize practical considerations for clinical translation. Collectively, these findings lay a foundation for data-driven and mechanistic insights into irAE development, with the potential to reduce ICI morbidity and mortality in the future.

Endocrine Side Effects in Patients Treated with Immune Checkpoint Inhibitors: A Narrative Review

Checkpoint inhibitors are monoclonal antibodies that elicit an anti-tumor response by stimulating immune system. Their use has improved the treatment of different types of cancer such as melanoma, breast carcinoma, lung, stomach, colon, liver, renal cell carcinoma, and Hodgkin's lymphoma, but several adverse events have been reported. Although the etiology of these effects is not completely understood, an uncontrolled activation of the immune system has been postulated. Indeed, some studies showed a cross reactivity of T cells, which acted against tumor antigens as well as antigens in the tissues of patients who developed immune-related adverse events. Despite the known possibility of developing immune-related adverse events, early diagnosis, monitoring during therapy, and treatment are fundamental for the best supportive care and administration of immune checkpoint inhibitors. The aim of this review is to guide the clinician in early diagnosis, management, and treatment of the endocrinological adverse effects in the major endocrine glands (thyroid, pituitary, adrenal, endocrine pancreas, and parathyroid).

Clonally expanded CD38hi cytotoxic CD8 T cells define the T cell infiltrate in checkpoint inhibitor-associated arthritis

Immune checkpoint inhibitor (ICI) therapies used to treat cancer, such as anti-PD-1 antibodies, can induce autoimmune conditions in some individuals. The T cell mechanisms mediating such iatrogenic autoimmunity and their overlap with spontaneous autoimmune diseases remain unclear. Here, we compared T cells from the joints of 20 patients with an inflammatory arthritis induced by ICI therapy (ICI-arthritis) with two archetypal autoimmune arthritides, rheumatoid arthritis (RA) and psoriatic arthritis (PsA). Single-cell transcriptomic and antigen receptor repertoire analyses highlighted clonal expansion of an activated effector CD8 T cell population in the joints and blood of patients with ICI-arthritis. These cells were identified as CD38hiCD127- CD8 T cells and were uniquely enriched in ICI-arthritis joints compared with RA and PsA and also displayed an elevated interferon signature. In vitro, type I interferon induced CD8 T cells to acquire the ICI-associated CD38hi phenotype and enhanced cytotoxic function. In a cohort of patients with advanced melanoma, ICI therapy markedly expanded circulating CD38hiCD127- T cells, which were frequently bound by the therapeutic anti-PD-1 drug. In patients with ICI-arthritis, drug-bound CD8 T cells in circulation showed marked clonal overlap with drug-bound CD8 T cells from synovial fluid. These results suggest that ICI therapy directly targets CD8 T cells in patients who develop ICI-arthritis and induces an autoimmune pathology that is distinct from prototypical spontaneous autoimmune arthritides.

PD-1 maintains CD8 T cell tolerance towards cutaneous neoantigens

The peripheral T cell repertoire of healthy individuals contains self-reactive T cells1,2. Checkpoint receptors such as PD-1 are thought to enable the induction of peripheral tolerance by deletion or anergy of self-reactive CD8 T cells3-10. However, this model is challenged by the high frequency of immune-related adverse events in patients with cancer who have been treated with checkpoint inhibitors11. Here we developed a mouse model in which skin-specific expression of T cell antigens in the epidermis caused local infiltration of antigen-specific CD8 T cells with an effector gene-expression profile. In this setting, PD-1 enabled the maintenance of skin tolerance by preventing tissue-infiltrating antigen-specific effector CD8 T cells from (1) acquiring a fully functional, pathogenic differentiation state, (2) secreting significant amounts of effector molecules, and (3) gaining access to epidermal antigen-expressing cells. In the absence of PD-1, epidermal antigen-expressing cells were eliminated by antigen-specific CD8 T cells, resulting in local pathology. Transcriptomic analysis of skin biopsies from two patients with cutaneous lichenoid immune-related adverse events showed the presence of clonally expanded effector CD8 T cells in both lesional and non-lesional skin. Thus, our data support a model of peripheral T cell tolerance in which PD-1 allows antigen-specific effector CD8 T cells to co-exist with antigen-expressing cells in tissues without immunopathology.

RNA Sequencing Reveals Unique Transcriptomic Signatures of the Thyroid in a Murine Lung Cancer Model Treated with PD-1 and PD-L1 Antibodies

Immune checkpoint inhibitors (ICI) are commonly associated with thyroid immune-related adverse events, yet the mechanism has not been fully elucidated. We aimed to further explore the mechanism of ICI-induced thyroid dysfunction by assessing changes induced in the thyroid transcriptome by ICI treatment (αPD-1/αPD-L1) in a lung cancer murine model. RNA-sequencing of thyroid tissues revealed 952 differentially expressed genes (DEGs) with αPD-1 treatment (|fold-change| ≥1.8, FDR < 0.05). Only 35 DEG were identified with αPD-L1, and we therefore focused on the αPD-1 group alone. Ingenuity Pathway Analysis revealed that of 952 DEGs with αPD-1 treatment, 362 were associated with functions of cell death and survival, with predicated activation of pathways for apoptosis and necrosis (Z = 2.89 and Z = 3.21, respectively) and negative activation of pathways for cell viability and cell survival (Z = -6.22 and Z = -6.45, respectively). Compared to previously published datasets of interleukin-1β and interferon γ-treated human thyroid cells, apoptosis pathways were similarly activated. However, unique changes related to organ inflammation and upstream regulation by cytokines were observed. Our data suggest that there are unique changes in gene expression in the thyroid associated with αPD-1 therapy. ICI-induced thyroid dysfunction may be mediated by increased tissue apoptosis resulting in destructive thyroiditis.

Clonally expanded, thyrotoxic effector CD8+ T cells driven by IL-21 contribute to checkpoint inhibitor thyroiditis

Autoimmune toxicity occurs in up to 60% of patients treated with immune checkpoint inhibitor (ICI) therapy for cancer and represents an increasing clinical challenge for expanding the use of these treatments. To date, human immunopathogenic studies of immune-related adverse events (IRAEs) have relied on sampling of circulating peripheral blood cells rather than affected tissues. Here, we directly obtained thyroid specimens from individuals with ICI-thyroiditis, one of the most common IRAEs, and compared immune infiltrates with those from individuals with spontaneous autoimmune Hashimoto's thyroiditis (HT) or no thyroid disease. Single-cell RNA sequencing revealed a dominant, clonally expanded population of thyroid-infiltrating cytotoxic CXCR6+ CD8+ T cells (effector CD8+ T cells) present in ICI-thyroiditis but not HT or healthy controls. Furthermore, we identified a crucial role for interleukin-21 (IL-21), a cytokine secreted by intrathyroidal T follicular (TFH) and T peripheral helper (TPH) cells, as a driver of these thyrotoxic effector CD8+ T cells. In the presence of IL-21, human CD8+ T cells acquired the activated effector phenotype with up-regulation of the cytotoxic molecules interferon-γ (IFN-γ) and granzyme B, increased expression of the chemokine receptor CXCR6, and thyrotoxic capacity. We validated these findings in vivo using a mouse model of IRAEs and further demonstrated that genetic deletion of IL-21 signaling protected ICI-treated mice from thyroid immune infiltration. Together, these studies reveal mechanisms and candidate therapeutic targets for individuals who develop IRAEs.

Association between CD8+ tumor-infiltrating lymphocytes and prognosis of non-small cell lung cancer patients treated with PD-1/PD-L1 inhibitors: a systematic review and meta-analysis

BACKGROUND

A meta-analysis method was used to investigate the prognostic value of CD8+ tumor-infiltrating lymphocytes (TILs) in non-small cell lung cancer (NSCLC) patients treated with PD-1/PD-L1 inhibitors.

METHODS

A database search of PubMed, Embase, Web of Science and Cochrane Library up until February 7th, 2023. A clinical study on the relationship between CD8+ TILs and PD-1/PD-L1 inhibitors in the therapeutics of NSCLC. RevMan 5.3 and StataMP 17.0 software were used for meta-analysis. The outcome indicators incorporated overall survival (OS), progression-free survival (PFS) and objective response rate (ORR).

RESULTS

Nineteen articles with 1488 patients were included. The analysis results showed that high CD8+ TILs were associated with better OS (HR=0.60, 95% CI: 0.46-0.77; P<0.0001), PFS (HR=0.68, 95% CI: 0.53-0.88; P=0.003) and ORR (OR=2.26, 95% CI: 1.52-3.36; P<0.0001) in NSCLC patients treated with PD-1/PD-L1 inhibitors. Subgroup analysis indicated that patients with high CD8+ TILs had good clinical prognostic benefits whether the location of CD8+ TILs was intratumoral or stromal, and compared with East Asian, high CD8+ TILs in Caucasians showed a better prognosis. High CD8+ TILs in peripheral blood did not improve OS (HR=0.83, 95% CI: 0.69-1.01; P=0.06) and PFS (HR=0.93, 95% CI: 0.61-1.14; P=0.76) in NSCLC patients receiving PD-1/PD-L1 inhibitors.

CONCLUSION

In spite of the location of CD8+ TILs, high densities of CD8+ TILs were predictive of treatment outcomes in NSCLC patients treated with PD-1/PD-L1 inhibitors. However, high CD8+ TILs in peripheral blood had no predictive effect.

Thyroid dysfunction after immune checkpoint inhibitor treatment in a single-center Chinese cohort: a retrospective study

BACKGROUND

Thyroid dysfunction is a common adverse event after immune checkpoint inhibitor (ICI) therapy. The clinical manifestations of thyroid immune-related adverse events (irAEs) are variable and the underlying mechanisms remain unclear.

PURPOSE

To identify the clinical and biochemical characteristics of Chinese patients with ICI-related thyroid dysfunction.

METHODS

We retrospectively reviewed patients with carcinoma who received ICI therapy and underwent evaluation of thyroid function during hospitalization at Peking Union Medical College Hospital between January 1, 2017 and December 31, 2020. Clinical and biochemical features were analyzed in patients who developed ICI-related thyroid dysfunction. Survival analyses were performed to determine the effect of thyroid autoantibodies on thyroid abnormalities and the impact of thyroid irAEs on clinical outcomes.

RESULTS

The cohort included 270 patients with a median follow-up of 17.7 months; 120 (44%) of these patients developed thyroid dysfunction on immunotherapy. The most common thyroid irAE was overt hypothyroidism (with/without transient thyrotoxicosis), which occurred in 38% of patients (n = 45), followed by subclinical thyrotoxicosis (n = 42), subclinical hypothyroidism (n = 27), and isolated overt thyrotoxicosis (n = 6). The median time to first clinical presentation was 49 days (interquartile range 23, 93) for thyrotoxicosis and 98 days (interquartile range 51, 172) for hypothyroidism. In patients treated with PD-1 inhibitors, hypothyroidism was strongly associated with younger age (odds ratio [OR] 0.44, 95% confidence interval [CI] 0.29-0.67; P < 0.001), previous thyroid disease (OR 4.30, 95% CI 1.54-11.99; P = 0.005), and a higher baseline thyroid-stimulating hormone level (OR 2.76, 95% CI 1.80-4.23; P < 0.001). Thyrotoxicosis was only associated with the baseline thyroid-stimulating hormone (TSH) level (OR 0.59, 95% CI 0.37-0.94; P = 0.025). Thyroid dysfunction after initiation of ICI therapy was associated with better progression-free survival (hazard ratio [HR] 0.61, 95% CI 0.44-0.86; P = 0.005) and overall survival (hazard ratio 0.67, 95% CI 0.45-0.99; P = 0.046). Anti-thyroglobulin antibody positivity increased the risk of thyroid irAEs.

CONCLUSIONS

The occurrence of thyroid irAEs with diverse phenotypes is common. Distinct clinical and biochemical characteristics suggest heterogeneity among different subgroups of thyroid dysfunction, which requires further research to explore the under mechanism.

Single-cell RNA sequencing reveals distinct T cell populations in immune-related adverse events of checkpoint inhibitors

PD-1 is an inhibitory receptor in T cells, and antibodies that block its interaction with ligands augment anti-tumor immune responses. The clinical potential of these agents is limited by the fact that half of all patients develop immune-related adverse events (irAEs). To generate insights into the cellular changes that occur during anti-PD-1 treatment, we performed single-cell RNA sequencing of circulating T cells collected from patients with cancer. Using the K-nearest-neighbor-based network graph-drawing layout, we show the involvement of distinctive genes and subpopulations of T cells. We identify that at baseline, patients with arthritis have fewer CD8 TCM cells, patients with pneumonitis have more CD4 TH2 cells, and patients with thyroiditis have more CD4 TH17 cells when compared with patients who do not develop irAEs. These data support the hypothesis that different populations of T cells are associated with different irAEs and that characterization of these cells' pre-treatment has the potential to serve as a toxicity-specific predictive biomarker.

Peripheral T cell cytotoxicity predicts the efficacy of anti-PD-1 therapy for advanced non-small cell lung cancer patients

Anti-programmed cell death-1 (PD-1) therapy exerts beneficial effects in a limited population of cancer patients. Therefore, more accurate diagnostics to predict the efficacy of anti-PD-1 therapy are desired. The present study investigated whether peripheral T cell cytotoxicity predicts the efficacy of anti-PD-1 therapy for advanced non-small cell lung cancer (NSCLC) patients. Advanced NSCLC patients treated with anti-PD-1 monotherapy (nivolumab or pembrolizumab) were consecutively enrolled in the present study. Peripheral blood samples were subjected to an analysis of peripheral T cell cytotoxicity and flow cytometry prior to the initiation of anti-PD-1 therapy. Peripheral T cell cytotoxicity was assessed using bispecific T-cell engager (BiTE) technology. We found that progression-free survival was significantly longer in patients with high peripheral T cell cytotoxicity (p = 0.0094). In the multivariate analysis, treatment line and peripheral T cell cytotoxicity were independent prognostic factors for progression-free survival. The analysis of T cell profiles revealed that peripheral T cell cytotoxicity correlated with the ratio of the effector memory population in CD4+ or CD8+ T cells. Furthermore, the results of flow cytometry showed that the peripheral CD45RA+CD25+/CD4+ T cell ratio was higher in patients with than in those without severe adverse events (p = 0.0076). These results indicated that the peripheral T cell cytotoxicity predicted the efficacy of anti-PD-1 therapy for advanced NSCLC patients.

Peripheral absolute eosinophil count identifies the risk of serious immune-related adverse events in non-small cell lung cancer

Background

Immune-related adverse events (irAEs) have drawn a lot of attention lately as a result of the predominance of immunotherapy in advanced non-small cell lung cancer (NSCLC). However, the clinical evidence for irAEs in real life is limited. In this paper, the occurrence of irAEs in Chinese NSCLC patients was examined, and possible risk factors for the emergence of severe irAEs were discovered.

Methods

Our retrospective investigation assessed the occurrence of adverse events (AEs) and prognosis of 213 patients who received immunotherapy for NSCLC. Using univariate and multivariate logistic regression models, the association between clinicopathological traits and the incidence of severe irAEs was investigated. To assess the prognostic impact of irAEs, survival data was analyzed.

Results

Among the 213 NSCLC patients, 122 (57.3%) had irAEs of any grade, and 38 (17.8%) had high-grade (grade 3-5) AEs. Baseline peripheral absolute eosinophil count (AEC) (HR 6.58, 95% CI: 1.5-28.8, P=0.012) was found to be an independent predictor of high-grade irAEs by multivariate analysis. The survival analysis revealed that patients with severe irAEs had worse OS (15.7 vs. 20.8 months, 95% CI: 11.6-19.8 vs. 16.0-25.5, P=0.026).

Conclusion

According to our findings, the peripheral absolute eosinophil count (AEC) is a reliable indicator of severe irAEs in NSCLC. Serious irAEs that occur in patients often reflect poor prognoses. In the future, high-grade irAEs should receive more attention.

CXCR5+CD8 T cells: Potential immunotherapy targets or drivers of immune-mediated adverse events?

CXCR5⁺CD8 T cells have attracted significant interest within multiple areas of immunology, cancer, and infection. This is in part due to their apparent dual functionality. These cells perform as cytotoxic cells in a variety of infection states including LCMV, HBV, HIV and SIV. However, CXCR5⁺CD8 T cells also associate with B cells in peripheral organs and function to stimulate B cell proliferation, antibody/B cell receptor class-switch, and antibody production. CXCR5⁺CD8 T cells are similar to CXCR5⁺CD4 T follicular helpers in their genetic make-up, B cell interactions, and functionality despite possessing elevated programmed cell death 1 and cytotoxic proteins. Within cancer CXCR5⁺CD8 T cells have risen as potential prognostic markers for overall survival and are functionally cytotoxic within tumor microenvironments. In inflammatory disease and autoimmunity, CXCR5⁺CD8 T cells are implicated in disease progression. During viral infection and cancer, CXCR5 expression on CD8 T cells generally is indicative of progenitor memory stem-like exhausted cells, which are more responsive to immune checkpoint blockade therapy. The use of immune checkpoint inhibitors to overcome immune exhaustion in cancer, and subsequent consequence of immune adverse events, highlights the dual nature of the cellular immune response. This review will detail the functionality of CXCR5⁺CD8 T cells in cancer and autoimmunity with potential repercussions during immune checkpoint blockade therapy discussed.

Inhibition of IL-17A Protects against Thyroid Immune-Related Adverse Events while Preserving Checkpoint Inhibitor Antitumor Efficacy

Immune checkpoint inhibitor (ICI) immunotherapy leverages the body's own immune system to attack cancer cells but leads to unwanted autoimmune side effects in up to 60% of patients. Such immune-related adverse events (IrAEs) may lead to treatment interruption, permanent organ dysfunction, hospitalization, and premature death. Thyroiditis is one of the most common IrAEs, but the cause of thyroid IrAEs remains unknown. In this study, we use a new, physiologically relevant mouse model of ICI-associated autoimmunity to identify a key role for type 3 immune cells in the development of thyroid IrAEs. Multiple lineages of IL-17A-producing T cells expand in thyroid tissue with ICI treatment. Intrathyroidal IL-17A-producing innate-like γδT17 cells were increased in tumor-free mice, whereas adaptive Th17 cells were also prominent in tumor-bearing mice, following ICI treatment. Furthermore, Ab-based inhibition of IL-17A, a clinically available therapy, significantly reduced thyroid IrAE development in ICI-treated mice with and without tumor challenge. Finally, combination of IL-17A neutralization with ICI treatment in multiple tumor models did not reduce ICI antitumor efficacy. These studies suggest that targeting Th17 and γδT17 cell function via the IL-17A axis may reduce IrAEs without impairing ICI antitumor efficacy and may be a generalizable strategy to address type 3 immune-mediated IrAEs.

TNF-α inhibitor ameliorates immune-related arthritis and pneumonitis in humanized mice

Objectives

This study aimed at establishing a mouse model of immune-related adverse in humanized BALB/c-hPD1/hCTLA4 mice to investigate their potential pathogenesis and explore therapeutic targets for immune-related arthritis and pneumonitis.

Methods

Humanized BALB/c-hPD1/hCTLA4 mice were injected with vehicle or collagen-specific antibodies (CA) and immune checkpoint inhibitors (ICI, ipilimumab, anti-human CTLA-4; and nivolumab, anti-human PD-1), and some mice were treated with anti-TNF-α antibody, leading to the control, collagen antibody-induced arthritis (CAIA), CAIA+ICI and treatment groups. The severity of clinical arthritis and pneumonitis in mice was monitored longitudinally and the pathological changes in the joints and lungs were histologically analyzed and the contents of lung hydroxyproline were measured. The frequency of different subsets of T cells was analyzed by flow cytometry and multiplex immunofluorescency.

Results

Compared with the control, the ICI group of mice developed the delayed onset of moderate degrees of arthritis while the CAIA+ICI group of mice exhibited the early onset of severe arthritis. Treatment with ICI caused severe pneumonitis, especially in the mice with CA. Flow cytometry analysis indicated a significantly higher frequency of splenic TNF-α+CD4+ and TNF-α+CD8+ T cells, but not other subsets of T cells tested, in the CAIA+ICI group of mice, relative to that in other groups of mice. Treatment with anti-TNF-α significantly mitigated the severity of arthritis and pneumonitis as well as deposition of collagen in lung of mice. The treatment also decreased the frequency of TNF-α+CD4+ and TNF-α+CD8+ T cells as well as effector memory T cells in the periphery lymph orangs and lungs of mice.

Conclusions

We successfully established a humanized mouse model of ICI-related severe arthritis and pneumonitis with a higher frequency of TNF-α+ T cells, which were significantly mitigated by anti-TNF-α treatment. Conceptually, ICI treatment can induce multiple autoimmune-like diseases in autoimmune-prone individuals and TNF-α+ T cells may be therapeutic targets for intervention of immune-related arthritis and pneumonitis.

Effects of high-fat diet on thyroid autoimmunity in the female rat

BACKGROUND

While contributions of dyslipidemia to autoimmune diseases have been described, its impact on thyroid autoimmunity (TA) is less clear. Programmed cell death 1(PD-1)/PD-ligand 1 (PD-L1) immune checkpoint is crucial in preventing autoimmune attack while its blockade exacerbates TA. We thus unveiled the effect of high-fat diet (HFD) on TA, focusing on the contribution of PD-1/PD-L1.

METHODS

Female Sprague Dawley (SD) rats were randomly fed with a regular diet or HFD (60% calories from fat) for 24 weeks. Then, thyroid ultrasonography was performed and samples were collected for lipid and thyroid-related parameter measure.

RESULTS

HFD rats exhibited hyperlipemia and abnormal biosynthesis of the unsaturated fatty acid in serum detected by lipidomics. These rats displayed a relatively lower echogenicity and increased inflammatory infiltration in thyroid accompanied by rising serum thyroid autoantibody levels and hypothyroidism, mimicking human Hashimoto's thyroiditis. These alterations were concurrent with decreased mRNA and immunostaining of intrathyroidal PD-1 and also serum PD-1 levels but not the PD-L1 expression, suggesting a role of a PD-1 pathway. Meanwhile, the infiltration of B and T cell, a key cellular event inhibited by the PD-1 signals, was enhanced in the thyroid of HFD rats, along with thyroid fibrosis and apoptosis.

CONCLUSIONS

Our data suggest that HFD triggers TA through a mechanism possibly involving downregulation of PD-1-related immunosuppression, providing a novel insight into the link between dyslipidemia and autoimmune toxicities.

Insights Into the Host Contribution of Endocrine Associated Immune-Related Adverse Events to Immune Checkpoint Inhibition Therapy

Blockade of immune checkpoints transformed the paradigm of systemic cancer therapy, enabling substitution of a cytotoxic chemotherapy backbone to one of immunostimulation in many settings. Invigorating host immune cells against tumor neo-antigens, however, can induce severe autoimmune toxicity which in many cases requires ongoing management. Many immune-related adverse events (irAEs) are clinically and pathologically indistinguishable from inborn errors of immunity arising from genetic polymorphisms of immune checkpoint genes, suggesting a possible shared driver for both conditions. Many endocrine irAEs, for example, have analogous primary genetic conditions with varied penetrance and severity despite consistent genetic change. This is akin to onset of irAEs in response to immune checkpoint inhibitors (ICIs), which vary in timing, severity and nature despite a consistent drug target. Host contribution to ICI response and irAEs, particularly those of endocrine origin, such as thyroiditis, hypophysitis, adrenalitis and diabetes mellitus, remains poorly defined. Improved understanding of host factors contributing to ICI outcomes is essential for tailoring care to an individual’s unique genetic predisposition to response and toxicity, and are discussed in detail in this review.

Thyroid Dysfunction from Treatments for Solid Organ Cancers

In recent years, cancer care has been transformed by immune-based and targeted treatments. Although these treatments are effective against various solid organ malignancies, multiple adverse effects can occur, including thyroid dysfunction. In this review, the authors consider treatments for solid organ cancers that affect the thyroid, focusing on immune checkpoint inhibitors, kinase inhibitors, and radioactive iodine-conjugated treatments (I-131-metaiodobenzylguanidine). They discuss the mechanisms causing thyroid dysfunction, provide a framework for their diagnosis and management, and explore the association of thyroid dysfunction from these agents with patient survival.

Immune checkpoint inhibitor-related thyroid dysfunction

Immune-related adverse events (irAEs) are caused by immune checkpoint inhibitors in several organs including the endocrine glands. Thyroid dysfunction (thyroid irAEs) is often observed among endocrine irAEs and is induced by blockade of programmed cell death 1 (PD-1), programmed death ligand 1, or PD-1 plus cytotoxic T-lymphocyte antigen 4. Endocrinologically, destructive thyroiditis or hypothyroidism is observed in most cases, whereas hyperthyroidism (Graves' disease) is rare. Most patients who develop destructive thyroiditis or hypothyroidism subsequently require thyroid hormone replacement therapy. Thyroid irAE development is associated with prolonged survival in patients with non-small cell lung carcinoma. The incidence of thyroid irAEs is higher in patients who are positive versus negative for anti-thyroid antibodies at baseline, suggesting that these antibodies can predict thyroid irAE development. Cytotoxic T cells, especially CD4 T cells, are reportedly involved in the development of destructive thyroiditis. In this review, we describe the clinical features, potential biomarkers, and mechanism of thyroid irAEs.

Sex Differences in Immunity

Strong epidemiological evidence now exists that sex is an important biologic variable in immunity. Recent studies, for example, have revealed that sex differences are associated with the severity of symptoms and mortality due to coronavirus disease 2019 (COVID-19). Despite this evidence, much remains to be learned about the mechanisms underlying associations between sex differences and immune-mediated conditions. A growing body of experimental data has made significant inroads into understanding sex-influenced immune responses. As physicians seek to provide more targeted patient care, it is critical to understand how sex-defining factors (e.g., chromosomes, gonadal hormones) alter immune responses in health and disease. In this review, we highlight recent insights into sex differences in autoimmunity; virus infection, specifically severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; and cancer immunotherapy. A deeper understanding of underlying mechanisms will allow the development of a sex-based approach to disease screening and treatment.

Immune-checkpoint inhibitors: long-term implications of toxicity

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, and providing new therapeutic indications in earlier-stage settings. As such, characterizing the long-term implications of receiving ICIs has grown in importance. An abundance of evidence exists describing the acute clinical toxicities of these agents, although chronic effects have not been as well catalogued. Nonetheless, emerging evidence indicates that persistent toxicities might be more common than initially suggested. While generally low-grade, these chronic sequelae can affect the endocrine, rheumatological, pulmonary, neurological and other organ systems. Fatal toxicities also comprise a diverse set of clinical manifestations and can occur in 0.4-1.2% of patients. This risk is a particularly relevant consideration in light of the possibility of long-term survival. Finally, the effects of immune-checkpoint blockade on a diverse range of immune processes, including atherosclerosis, heart failure, neuroinflammation, obesity and hypertension, have not been characterized but remain an important area of research with potential relevance to cancer survivors. In this Review, we describe the current evidence for chronic immune toxicities and the long-term implications of these effects for patients receiving ICIs.

Increased Risk of Thyroid Dysfunction by PD-1 and CTLA-4 Blockade in Patients Without Thyroid Autoantibodies at Baseline

BACKGROUND

Previous studies showed that although the risk of thyroid dysfunction [thyroid immune-related adverse events (irAEs)] induced by anti-programmed cell death-1 antibodies (PD-1-Ab) was as low as 2% to 7% in patients negative for anti-thyroid antibodies (ATAs) at baseline, it was much higher (30%-50%) in patients positive for ATAs. However, whether a similar increase occurs with combination therapy using PD-1-Ab plus anti-cytotoxic T-lymphocyte antigen-4 antibody (CTLA-4-Ab) is unknown.

METHODS

A total of 451 patients with malignancies treated with PD-1-Ab, CTLA-4-Ab, or a combination of PD-1-Ab and CTLA-4-Ab (PD-1/CTLA-4-Abs) were evaluated for ATAs at baseline and for thyroid function every 6 weeks for 24 weeks after treatment initiation and then observed until the last clinical visit.

RESULTS

Of the 451 patients, 51 developed thyroid irAEs after immunotherapy [41 of 416 (9.9%) treated with PD-1-Ab, 0 of 8 (0%) treated with CTLA-4-Ab, and 10 of 27 (37.0%) treated with PD-1/CTLA-4-Abs]. The cumulative incidence of thyroid irAEs was significantly higher in patients who were positive vs negative for ATAs at baseline after both PD-1-Ab [28/87 (32.2%) vs 13/329 (4.0%), P < 0.001] and PD-1/CTLA-4-Abs [6/10 (60.0%) vs 4/17 (23.5%), P < 0.05] treatments. The risk of thyroid irAEs induced by PD-1/CTLA-4Abs, which was significantly higher than that induced by PD-1-Ab, in patients negative for ATAs at baseline was not statistically different from that induced by PD-1-Ab in patients positive for ATAs at baseline.

CONCLUSIONS

This study showed that the incidence of thyroid irAEs was high and not negligible after PD-1/CTLA-4-Abs treatment even in patients negative for ATAs at baseline.

Inborn Errors of Immunity and Their Phenocopies: CTLA4 and PD-1

Elucidating links between genotype and phenotype in patients with rare inborn errors of immunity (IEIs) provides insights into mechanisms of immune regulation. In many autosomal dominant IEIs, however, variation in expressivity and penetrance result in complex genotype-phenotype relations, while some autosomal recessive IEIs are so rare that it is difficult to draw firm conclusions. Phenocopies arise when an environmental or non-genetic factor replicates a phenotype conferred by a specific genotype. Phenocopies can result from therapeutic antibodies or autoantibodies that target a protein to replicate aspects of the phenotype conferred by mutations in the gene encoding the same protein. Here, we consider IEIs arising from rare genetic variants in CTLA4 and PDCD1 and compare clinical and laboratory manifestations arising as drug-induced phenocopies (immune related adverse events, IRAEs) in cancer patients treated with immune checkpoint inhibitors (ICI) and identify outstanding questions regarding mechanism of disease.

T cell characteristics associated with toxicity to immune checkpoint blockade in patients with melanoma

Severe immune-related adverse events (irAEs) occur in up to 60% of patients with melanoma treated with immune checkpoint inhibitors (ICIs). However, it is unknown whether a common baseline immunological state precedes irAE development. Here we applied mass cytometry by time of flight, single-cell RNA sequencing, single-cell V(D)J sequencing, bulk RNA sequencing and bulk T cell receptor (TCR) sequencing to study peripheral blood samples from patients with melanoma treated with anti-PD-1 monotherapy or anti-PD-1 and anti-CTLA-4 combination ICIs. By analyzing 93 pre- and early on-ICI blood samples and 3 patient cohorts (n = 27, 26 and 18), we found that 2 pretreatment factors in circulation-activated CD4 memory T cell abundance and TCR diversity-are associated with severe irAE development regardless of organ system involvement. We also explored on-treatment changes in TCR clonality among patients receiving combination therapy and linked our findings to the severity and timing of irAE onset. These results demonstrate circulating T cell characteristics associated with ICI-induced toxicity, with implications for improved diagnostics and clinical management.

Survival benefit of endocrine dysfunction following immune checkpoint inhibitors for nonthyroidal cancers

PURPOSE OF REVIEW

Our goal is to review pertinent data evaluating the association between immune checkpoint inhibitor (ICI)-induced endocrine dysfunction and survival in cancer patients as well as to understand the potential molecular links between these.

RECENT FINDINGS

ICIs have revolutionized cancer therapy but have also led to multiple immune-related adverse events (irAEs). Studies have demonstrated a link between the development of irAEs and improved survival, suggesting that ICI-induced antitumor immunity and autoimmunity are coupled. Thyroid irAEs are most frequently and strongly associated with improved survival, particularly in the context of overt thyroid dysfunction. Other endocrine irAEs, such as hypophysitis and diabetes are quite rare wherein the treatment approach or the disease process itself may mitigate improvement in survival. Preclinical and translational data indicate a role for CD4+ T cells, regulatory T cells and/or cytokines mediating irAEs, including thyroiditis.

SUMMARY

The development of irAEs is associated with improved tumor responses and survival in cancer patients. Thyroid irAEs, alone or in combination with other irAEs, are most strongly associated with improved outcomes. Biomarkers of response to ICIs are lacking, despite well-characterized pathologic and genomic susceptibilities predicting ICI efficacy. Early detection of thyroid irAEs may identify patients most likely to have durable antitumor response to ICIs. Although irAEs and antitumor immunity appear 'coupled', translational studies indicate the potential for their 'uncoupling', which could enable antitumor efficacy with greater safety margins.