Immunohistochemical analysis of lichenoid reactions in patients treated with anti-PD-L1 and anti-PD-1 therapy

Checkpoint inhibitor-induced lichen planus differs from spontaneous lichen planus on the clinical, histological, and gene expression level

Background

Although highly efficacious, immune checkpoint inhibitors induce a multitude of immune-related adverse events including lichenoid skin reactions (irLP) that are often therapy-resistant.

Objectives

To compare the clinical, histological, and transcriptional features of irLP with spontaneous lichen planus (LP).

Methods

Clinical and histological presentations of irLP and LP, as well as the gene expression profiles of irLP and LP lesional and healthy skin were assessed.

Results

irLP differed considerably from LP with regard to the distribution pattern of skin lesions with irLP appearing mostly in an exanthematous form, whereas lesions were more localized in the LP group. Histologically, dermal lymphocyte infiltration was significantly lower in irLP compared with LP, whereas lymphocyte exocytosis and apoptotic keratinocytes were significantly higher in irLP. Gene expression analysis revealed irLP to have a more inflammatory profile with elevated IFNG levels and a possible role of phagosome signaling compared with LP.

Limitations

The study is descriptive and necessitates further investigation with larger cohorts and broader analyses.

Conclusion

irLP differs from spontaneous LP on the clinical, histopathological, and gene expression level. The inflammatory gene signature in irLP suggests that topical JAK inhibitors could be an effective treatment, targeting local skin inflammation without systemic immunosuppression.

Cutaneous Hypersensitivity Reactions to Immune Checkpoint Inhibitors

The introduction of immune checkpoint inhibitors (ICIs) has transformed the management of various malignancies. Alongside their therapeutic success, the widespread application of ICIs has unveiled a spectrum of immune-related adverse events (irAEs), most often affecting the skin. Cutaneous irAEs (cirAEs) encompass a range from common morbilliform and lichenoid rashes to more severe conditions such as bullous dermatoses and psoriasiform eruptions, each presenting distinct clinical challenges. Moreover, less common but clinically severe cutaneous reactions like toxic epidermal necrolysis have also been observed. cirAEs are frequently observed, with an incidence ranging from 37% to 70% for anti-cytotoxic T lymphocyte-associated antigen-4 antibodies and 17% to 40% for anti- programmed death-1/anti-programmed death ligand-1 antibodies. Recognizing the critical need for effective therapeutic strategies, this review carefully examines current approaches and guidelines for managing cirAEs.

Cardiovascular events after cancer immunotherapy as oncologic emergencies: Analyses of 610 head and neck cancer patients treated with immune checkpoint inhibitors

BACKGROUND

Cardio-oncology and emergency medicine are closely collaborative, as many cardiac events in cancer patients require evaluation and treatment in the emergency department (ED). Immune checkpoint inhibitors (ICIs) have become a common treatment for patients with head and neck cancer (HNC). However, the immune-related adverse events (irAEs) from ICIs can be clinically significant.

METHODS

We reviewed and analyzed cardiovascular diagnoses among HNC patients who received ICI during the period April 1, 2016-December 31, 2020 in a large tertiary cancer center. Demographics, clinical and cancer-related data were abstracted, and billing databases were queried for cardiovascular disease (CVD)-related diagnosis using International Classification of Disease-version10 (ICD-10) codes. We recorded receipt of care at the ED as one of the outcome variables.

RESULTS

A total of 610 HNC patients with a median follow-up time of 12.3 months (median, interquartile range = 5-30 months) comprised our study cohort. Overall, 25.7% of patients had pre-existing CVD prior to ICI treatment. Of the remaining 453 patients without pre-existing CVD, 31.5% (n = 143) had at least one CVD-related diagnosis after ICI initiation. Tachyarrhythmias (91 new events) was the most frequent CVD-related diagnosis after ICI. The time to diagnosis of myocarditis from initiation of ICI occurred the earliest (median 2.5 months, 1.5-6.8 months), followed by myocardial infarction (3.7, 0.5-9), cardiomyopathy (4.5, 1.6-7.3), and tachyarrhythmias (4.9, 1.2-11.4). Patients with myocarditis and tachyarrhythmias mainly presented to the ED for care.

CONCLUSION

The use of ICI in HNC is still expanding and the spectrum of delayed manifestation of ICI-induced cardiovascular toxicities is yet to be fully defined in HNC survivors.

Immune checkpoint inhibitor-induced lichenoid drug eruption-sparing scar burns

The authors present a striking case of a patient experiencing a lichenoid drug eruption secondary to immunotherapy, curiously sparing scarred skin from past burns. We observed vastly higher amounts of inflammatory lymphoid cells staining for PD-1; 70% in skin with a lichenoid drug reaction and 50% in scarred skin. The lack of a lichenoid reaction at sites of scarred skin may indicate that a basement membrane component may be causative for a lichenoid drug eruption.

Oral Baricitinib in the Treatment of Cutaneous Lichen Planus

Background

Cutaneous lichen planus (LP) is a recalcitrant, difficult-to-treat, inflammatory skin disease characterized by pruritic, flat-topped, violaceous papules on the skin. Baricitinib is an oral Janus kinase (JAK) 1/2 inhibitor that interrupts the signaling pathway of interferon (IFN)-γ, a cytokine implicated in the pathogenesis of LP.

Methods

In this phase II trial, twelve patients with cutaneous LP received baricitinib 2 mg daily for 16 weeks, accompanied by in-depth spatial, single-cell, and bulk transcriptomic profiling of pre-and post-treatment samples.

Results

An early and sustained clinical response was seen with 83.3% of patients responsive at week 16. Our molecular data identified a unique, oligoclonal IFN-γ, CD8+, CXCL13+ cytotoxic T-cell population in LP skin and demonstrate a rapid decrease in interferon signature within 2 weeks of treatment, most prominent in the basal layer of the epidermis.

Conclusion

This study demonstrates the efficacy and molecular mechanisms of JAK inhibition in LP. Trial Registration Number : NCT05188521.

Successful treatment of immune-related lichenoid dermatitis by Weiling decoction in a patient with non-small cell lung cancer: A case report and review of literature

BACKGROUND

Immune checkpoint inhibitors (ICIs) have emerged as a revolutionary therapy in advanced squamous non-small cell lung cancer (sqNSCLC) and ushered a new era of immunotherapy. Despite of remarkable outcomes, a wide spectrum of immune-related adverse events (irAEs) was reported, among which cutaneous reactions were the most common. Cutaneous irAEs were mainly managed by glucocorticoids, whereas prolonged use of glucocorticoids may cuase kinds of side effects, especially in elderly paitients, and diminish the anti-tumor efficacy of ICIs, thus finding a safe and effective alternative approach to managing cutaneous irAEs is imperative.

CASE SUMMARY

A 71-year-old man who was diagnosed with advanced sqNSCLC suffered from sporadic maculopapulars one week later after the fifth cycle of sintilimab treatment, and the skin lesions had been deteriorating rapidly. Skin biopsy revealed epidermal parakeratosis with a dense band-like lymphocytic infiltrate and acanthosis, indicating a diagnosis of immune-induced lichenoid dermatitis. Oral administration of traditional Chinese herbal formula modified Weiling decoction significantly alleviated the symptoms of the patient. The dosage of Weiling decoction were maintained for about three months without recurrence of cutaneous adverse reactions and any other side effects. The patient refused to receive further anti-tumor medication and stayed alive without disease progression at follow up.

CONCLUSION

We present modified Weiling decoction successfully ameliorates immune-induced lichenoid dermatitis in a patient with sqNSCLC for the first time. This report indicates that Weiling decoction may be an effective and safe complementary or alternative approach for the treatment of cutaneous irAEs. Further investigation of the underling mechanism is required in the future.

Molecular Mechanisms of Cutaneous Immune-Related Adverse Events (irAEs) Induced by Immune Checkpoint Inhibitors

Over the past few decades, immune checkpoint inhibitors (ICIs) have emerged as promising therapeutic options for the treatment of various cancers. These novel treatments effectively target key mediators of immune checkpoint pathways. Currently, ICIs primarily consist of monoclonal antibodies that specifically block cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1), programmed cell death-ligand 1 (PD-L1), and lymphocyte activation gene 3 protein (LAG-3). Despite the notable efficacy of ICIs in cancer treatment, they can also trigger immune-related adverse events (irAEs), which present as autoimmune-like or inflammatory conditions. IrAEs have the potential to affect multiple organ systems, with cutaneous toxicities being the most commonly observed. Although cutaneous irAEs are typically of low-grade severity and can usually be managed effectively, there are cases where severe irAEs can become life-threatening. Therefore, early recognition and a comprehensive understanding of the mechanisms underlying cutaneous irAEs are crucial for improving clinical outcomes in cancer patients. However, the precise pathogenesis of cutaneous irAEs remains unclear. This review focuses on the skin manifestations induced by ICIs, the prognosis related to cutaneous irAEs, and the exploration of potential mechanisms involved in cutaneous irAEs.

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.

Cutaneous Side Effects of Modern Targeted Therapy and Immunotherapy in Patients with Dermatological Malignancies

The advent of immunotherapy and targeted therapies in treating dermatological malignancies has dramatically changed the landscape of dermato-oncology in recent years. Their superior efficacy compared to previous therapeutic options, such as chemotherapy, has resulted in their use in treating devastating malignancies, such as melanoma or unresectable/metastatic basal cell and squamous cell carcinoma. Skin toxicity is a critical safety consideration, among other adverse reactions, that can occur under treatment with these agents. This article aims to summarize the cutaneous side effects of immune checkpoint inhibitors and targeted dermato-oncological therapies. Although the skin side effects of these agents are primarily mild, they can occasionally affect the decision for treatment continuation and the quality of life of the affected patients. Therefore, physicians must be acquainted with the specific cutaneous toxicity profile of such treatments to mitigate their impact on the patients and optimize the overall outcome of dermato-oncological therapy.

Immune-related adverse events in checkpoint blockade: Observations from human tissue and therapeutic considerations

Checkpoint inhibitors (CPIs) are monoclonal antibodies which, by disrupting interactions of immune checkpoint molecules with their ligands, block regulatory immune signals otherwise exploited by cancers. Despite revolutionary clinical benefits, CPI use is associated with an array of immune-related adverse events (irAEs) that mirror spontaneous autoreactivity. Severe irAEs necessitate pausing or stopping of CPI therapy and use of corticosteroids and/or other immunomodulatory interventions. Despite increasingly widespread CPI use, irAE pathobiology remains poorly understood; its elucidation may point to targeted mitigation strategies and uncover predictive biomarkers for irAE onset in patients, whilst casting new light on mechanisms of spontaneous immune-mediated disease. This review focuses on common CPI-induced irAEs of the gut, skin and synovial joints, and how these compare to immune-mediated diseases such as ulcerative colitis, vitiligo and inflammatory arthritis. We review current understanding of the immunological changes reported following CPI therapy at the level of peripheral blood and tissue. Many studies highlight dysregulation of cytokines in irAE-affected tissue, particularly IFNγ and TNF. IrAE-affected tissues are also predominantly infiltrated by T-cells, with low B-cell infiltration. Whilst there is variability between studies, patients treated with anti-programmed cell death-1 (PD-1)/PDL-1 therapies seem to exhibit CD8+ T-cell dominance, with CD4+ T-cells dominating in those treated with anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) monotherapy. Interestingly, CD8+CXCR3+ T-cells have been reported to be elevated in gastrointestinal, dermatological and musculoskeletal -irAE affected tissues. These findings may highlight potential opportunities for therapeutic development or re-deployment of existing therapies to prevent and/or improve the outcome of irAEs.

Cutaneous lichenoid drug eruptions: A narrative review evaluating demographics, clinical features and culprit medications

Cutaneous lichenoid drug eruptions (LDE) are adverse drug reactions (ADR) characterized by symmetric, erythematous, violaceous papules reminiscent but rarely fully characteristic of lichen planus (LP). We aimed to analyse the literature describing cases of LDE within the last 20 years to provide additional insight into culprit drugs, typical latency to onset of the eruption, the spectrum of clinical presentations, severity and management. A literature search was conducted in MEDLINE between January 2000 and 27 January 2021. The keywords 'lichenoid drug rash' and 'lichenoid drug eruption' were used. Cases were included if LDE diagnosis was made, and culprit drugs were identified. A total of 323 cases with LDE were identified from 163 published case reports and studies. The mean patient age was 58.5 years (1 month to 92 years), and 135 patients (41.8%) were female. Checkpoint inhibitors (CKI) were the most frequently reported culprit drugs (136 cases; 42.1%), followed by tyrosine kinase inhibitors (TKI) (39 cases; 12.0%) and anti-TNF-α-monoclonal antibodies (13 cases; 4.0%). The latency between initiation of the drug and manifestation was 15.7 weeks (range: 0.1-208 weeks). After discontinuing the culprit drug, the median time to resolution was 14.2 weeks (range: 0.71-416 weeks). One hundred thirty-six patients (42.1%) were treated with topical, and 54 patients (16.7%) with systemic glucocorticoids. Overall, we conclude that, albeit rare, LDE is challenging to diagnose ADR induced by mostly CKI, TKI, and biologics. Treatment modalities resemble that of lichen planus, and the culprit drugs had to be discontinued in only 26%, which is low compared with other types of adverse drug reactions. This is probably due to the low risk of aggravation (e.g. toxic epidermal necrolysis) if the drug is continued and the benefit/risk ratio favouring the drug, as is often the case in cancer therapy.

Cutaneous manifestations associated with immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that block key mediators of tumor-mediated immune evasion. The frequency of its use has increased rapidly and has extended to numerous cancers. ICIs target immune checkpoint molecules, such as programmed cell death protein 1 (PD-1), PD ligand 1 (PD-L1), and T cell activation, including cytotoxic T-lymphocyte-associated protein-4 (CTLA-4). However, ICI-driven alterations in the immune system can induce various immune-related adverse events (irAEs) that affect multiple organs. Among these, cutaneous irAEs are the most common and often the first to develop. Skin manifestations are characterized by a wide range of phenotypes, including maculopapular rash, psoriasiform eruption, lichen planus-like eruption, pruritus, vitiligo-like depigmentation, bullous diseases, alopecia, and Stevens-Johnson syndrome/toxic epidermal necrolysis. In terms of pathogenesis, the mechanism of cutaneous irAEs remains unclear. Still, several hypotheses have been proposed, including activation of T cells against common antigens in normal tissues and tumor cells, increased release of proinflammatory cytokines associated with immune-related effects in specific tissues/organs, association with specific human leukocyte antigen variants and organ-specific irAEs, and acceleration of concurrent medication-induced drug eruptions. Based on recent literature, this review provides an overview of each ICI-induced skin manifestation and epidemiology and focuses on the mechanisms underlying cutaneous irAEs.

A case of severe nivolumab-induced lichen planus pemphigoides in a child with metastatic spitzoid melanoma

Dermatologic reactions are among the most common adverse events of antiprogrammed cell death-1 (anti-PD-1) monoclonal antibodies agents and include maculopapular rash, psoriasiform rash, lichenoid eruptions, autoimmune bullous disorders, and vitiligo. Here, we present a case of a 12-year-old African American male with metastatic spitzoid melanoma treated with nivolumab who developed a mild lichenoid eruption that progressed to a severe case of lichen planus pemphigoides (LPP). Management was complex given the patient's age and history and included hospitalization for intravenous steroids, an intensive topical steroid regimen, methotrexate, and discontinuation of nivolumab. This case illustrates a rare but dramatic progression from a mild LP-like eruption to severe bullous lichenoid eruption, most consistent with LPP, as well as the diagnostic and treatment challenges in the setting of a pediatric patient on nivolumab.

Risk of Lichen Sclerosus and Lichen Planus in Patients Receiving Immune Checkpoint Inhibitors

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are recommended for various types of cancer. On the other hand, these ICIs may cause immune-related adverse events (irAEs). Lichen sclerosus (LS) and lichen planus (LP) are two distinct phenotypes of irAEs that occur in a subset of patients treated with ICIs. These adverse effects have a detrimental effect on the patient's quality of life and treatment phases; however, the clinical evaluation and assessment of LS and LP remain uncertain. This study aims to assess and evaluate the risk of LS and LP associated with the use of ICIs via a systematic review of the literature and the USA FDA Adverse Events FAERS database.

METHOD

The study searched electronic databases such as PubMed, Medline, Cochrane, and Google Scholar for case reports on immune-checkpoint-inhibitor-associated lichen sclerosus and lichen planus published in English between inception and 31 December 2021. The FDA's adverse event reporting system (FAERS) database was also analyzed.

RESULTS

Thirty-eight case reports and two retrospective studies with a total of 101 patients, in addition to the FAERS data, were evaluated. More cases involved lichen planus (78.9%) than lichen sclerosis (21%). Nivolumab and pembrolizumab were most frequently reported with LS and LP, among other ICIs. Thirty-six out of thirty-eight patients with LS or LP experienced complete remission, while two patients experienced partial remission. Most of the cases had an excellent response to corticosteroids (92.1%), while the remainder had moderate (5.2%) and poor (2.6%) responses. Additionally, the reporting odds ratio (ROR) of the FAERS database indicated a favorable association for ICIs, the risk of LP, and LS. A stronger association was uniquely found between nivolumab and pembrolizumab.

CONCLUSION

There have been published case reports for these adverse events. Healthcare providers should be aware of the possibility of lichen sclerosis and lichen planus developing in patients receiving ICIs which could necessitate hospitalization or discontinuation. Regulatory agencies are advised to monitor the risks as a potential safety signal.

Cutaneous adverse events in patients treated with PD-1/PD-L1 checkpoint inhibitors and their association with survival: a systematic review and meta-analysis

Immune-related cutaneous adverse events (irCAEs) in patients treated with programmed cell death-1/programmed death-ligand 1 (PD-1/PD-L1) checkpoint inhibitors may be associated with better clinical outcomes. However, the extent to which these results can be extrapolated to all tumour types remains unclear. Herein, we conducted a meta-analysis of patients with cancer receiving anti-PD-1/PD-L1 immunotherapy, to determine the cumulative incidence of irCAEs and their association with survival. We systematically searched six databases (PubMed, Embase, Cochrane, CNKI, CSPD, and CQVIP database) for all cohort studies reporting the relationship between irCAEs and patient survival from the time of database construction to 1 November, 2020. The primary outcomes were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS), with complete remission (CR), partial remission (PR), stable disease (SD), and progressive disease (PD) as secondary outcomes. Patients with irCAEs exhibited higher ORR, and were more likely to report CR and PR and less likely to develop PD than those who did not experience irCAEs. Moreover, the occurrence of irCAEs was significantly associated with both favourable PFS and OS. Therefore, patients with irCAEs have better survival benefit and a significantly lower risk of tumour progression or death. Hence, the occurrence of irCAEs may be a useful marker for predicting the clinical efficacy of anti-PD-1/PD-L1 immunotherapy.

Immunohistochemical Study of the PD-1/PD-L1 Pathway in Cutaneous Lupus Erythematosus

The pathomechanism of various autoimmune diseases is known to be associated with the altered function of programmed cell death 1/programmed cell death ligand 1 (PD-1/PD-L1) axis. We aimed to investigate the role of this pathway and inflammatory cell markers in subtypes of cutaneous lupus erythematosus (CLE): discoid lupus erythematosus (DLE), subacute CLE (SCLE) and toxic epidermal necrolysis (TEN)-like lupus, a hyperacute form of acute CLE (ACLE). Ten skin biopsy samples from 9 patients were analyzed with immunohistochemistry regarding the following markers: CD3, CD4, CD8, Granzyme B, CD123, CD163, PD-1, PD-L1. Our group consisted of 4 SCLE (2 idiopathic (I-SCLE) and 2 PD-1 inhibitor-induced (DI-SCLE)), 4 DLE and 1 TEN-like lupus cases. From the latter patient two consecutive biopsies were obtained 1 week apart. Marker expression patterns were compared through descriptive analysis. Higher median keratinocyte (KC) PD-L1 expression was observed in the SCLE group compared to the DLE group (65% and 5%, respectively). Medians of dermal CD4, Granzyme B (GB), PD-1 positive cell numbers and GB+/CD8⁺ ratio were higher in the DLE group than in the SCLE group. The I-SCLE and DI-SCLE cases showed many similarities, however KC PD-L1 expression and dermal GB positive cell number was higher in the former. The consecutive samples of the TEN-like lupus patient showed an increase by time within the number of infiltrating GB+ cytotoxic T-cells and KC PD-L1 expression (from 22 to 43 and 30%–70%, respectively). Alterations of the PD-1/PD-L1 axis seems to play a role in the pathogenesis of CLE.

Immune cell subsets in interface cutaneous immune-related adverse events (cirAEs) associated with anti-PD-1 therapy resemble acute graft vs host disease more than lichen planus

Background

Checkpoint immunotherapy is frequently associated with cutaneous immune‐related adverse events (cirAEs), and among those, the most common subtype shows interface reaction patterns that have been likened to lichen planus (LP); however, cutaneous acute graft versus host disease (aGVHD) may be a closer histopathologic comparator. We used quantitative pathology to compare the immunologic composition of anti‐PD‐1‐associated interface reactions to LP and aGVHD to assess for similarities and differences between these cutaneous eruptions.

Methods

Immunohistochemistry for CD4, CD8, CD68, PD‐1, and PD‐L1 was performed on formalin‐fixed paraffin‐embedded tissue from patients with anti‐PD‐1 interface cirAEs (n = 4), LP (n = 9), or aGVHD (n = 5). Densities of immune cell subsets expressing each marker were quantified using the HALO image analysis immune cell module. Plasma cell and eosinophil density were quantified on routine H&E slides.

Results

Specimens from patients with anti‐PD‐1 interface cirAEs showed equivalent total cell densities and immune cell composition to those with aGVHD. Patients with LP showed higher total immune cell infiltration, higher absolute T‐cell densities, increased CD8 proportion, and reduced histiocytic component. The cases with the highest plasma cell counts were all anti‐PD‐1 interface cirAEs and aGVHD.

Conclusion

The composition of immune cell subsets in anti‐PD‐1 interface cirAEs more closely resembles the immune response seen in aGVHD than LP within our cohort. This warrants a closer look via advanced analytics and may have implications for shared pathogenesis and potential treatment options.

Cutaneous Adverse Events Associated with Immune Checkpoint Inhibitors: A Review Article

Immune checkpoint inhibitors (ICIs) have emerged as novel options that are effective in treating various cancers. They are monoclonal antibodies that target cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1), and programmed cell death-ligand 1 (PD-L1). However, activation of the immune systems through ICIs may concomitantly trigger a constellation of immunologic symptoms and signs, termed immune-related adverse events (irAEs), with the skin being the most commonly involved organ. The dermatologic toxicities are observed in nearly half of the patients treated with ICIs, mainly in the form of maculopapular rash and pruritus. In the majority of cases, these cutaneous irAEs are self-limiting and manageable, and continuation of the ICIs is possible. This review provides an overview of variable ICI-mediated dermatologic reactions and describes the clinical and histopathologic presentation. Early and accurate diagnosis, recognition of severe toxicities, and appropriate management are key goals to achieve the most favorable outcomes and quality of life in cancer patients.

Nivolumab‑induced lichenoid granulomatous stomatitis in a patient with advanced melanoma: A case report

Lichenoid granulomatous reactions (LGR) are granulomatous inflammations of the skin and oral mucosa, also sharing features of lichenoid lesions. Thus, the present study refers to lichenoid granulomatous dermatitis (LGD) and lichenoid granulomatous stomatitis (LGS). LGR is a condition that can be triggered by drugs, diseases or environmental causes. In the present case study, anti-PD1 (nivolumab) medication had a detrimental effect on the oral mucosa, which clinicaly and histologicaly proved to be LGS. Checkpoint inhibitors consitute a cornerstone in the current treatment of several types of cancer, of which cutaneous melanoma is the best example. Oral lichenoid responses following anti-PD-1 therapy have been recorded in few case reports and small case series. To the best of our knowledhe, this is the first case of LGS being reported as a side effect of immune checkpoint inhibitor treatment.

Dermatologic immune-related adverse events: The toxicity spectrum and recommendations for management

Immune checkpoint inhibitors are a new class of oncologic drugs that act via the inhibition of checkpoints, thereby unlocking the immune system to attack cancer cells. Their emergence has radically changed the concept of therapy in oncologic patients. However, despite their overall favorable profile, their use has been associated with specific toxicities that may potentially affect treatment. The so-called immune-related adverse events (irAEs) mostly correspond to dysimmune reactions that can affect nearly every organ system, in theory, notably with the development of colitis, hepatitis, pneumonitis, or thyroiditis. Dermatologic irAEs are also among the most common, reaching a rate of approximately 40%. They are characterized by a wide phenotypic range, including mainly eczematous or lichenoid rashes, psoriasis, or autoimmune bullous disorders. Pruritus may accompany the aforementioned rashes or develop as an isolated symptom without the presence of skin changes. Depigmentation and hair/nail changes can be also observed in association with immune checkpoint inhibitor treatment. In the current article, we present an overview of the clinical spectrum of irAEs and provide tips for early recognition and management of dermatologic irAEs. We highlight the role that dermatologists can play in relieving patients and allowing for oncologic treatment to be maintained and administered more safely.

Immune-Related Oral, Otologic, and Ocular Adverse Events

Emerging immunotherapeutic agents, including immune checkpoint inhibitors targeting cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), programmed cell death protein 1 (PD-1), and programmed cell death protein ligand 1 (PD-L1), have revolutionized cancer treatment. The first immune checkpoint inhibitor (ICI) ipilimumab, an anti-CTLA-4, was approved in 2011. Since then, the US Food and Drug Administration (FDA) has approved more than half a dozen immune checkpoint inhibitors to treat various malignancies. These agents are part of a broader class of chemotherapy agents termed immunotherapy, which selectively target different steps in the immune response cascade to upregulate the body's normal response to cancer. While the effects of traditional chemotherapy are well known, the toxicity profile of emerging immune therapies is not fully elucidated. They have been associated with atypical side effects labeled collectively as immune-related adverse events (irAEs).

European recommendations for management of immune checkpoint inhibitors-derived dermatologic adverse events. The EADV task force 'Dermatology for cancer patients' position statement

The introduction of immune checkpoint inhibitors (ICIs) opened a new era in oncologic therapy. The favourable profile of ICIs in terms of efficacy and safety can be overshadowed by the development of immune-related adverse events (irAEs). Dermatologic irAEs (dirAEs) appear in about 40% of patients undergoing immunotherapy and mainly include maculopapular, psoriasiform, lichenoid and eczematous rashes, auto-immune bullous disorders, pigmentary disorders, pruritus, oral mucosal lesions, hair and nail changes, as well as a few rare and potentially life-threatening toxicities. The EADV task force Dermatology for Cancer Patients merged the clinical experience of the so-far published data, incorporated the quantitative and qualitative characteristics of each specific dirAEs, and released dermatology-derived, phenotype-specific treatment recommendations for cutaneous toxicities (including levels of evidence and grades of recommendation). The basic principle of management is that the interventions should be tailored to serve the equilibrium between patients' relief from the symptoms and signs of skin toxicity and the preservation of an unimpeded oncologic treatment.

Meet the expert: Topical management of vulvar dermatoses

Vulvar dermatoses are often debilitating chronic skin conditions associated with pain and pruritus. In oncologic patients, cancer treatments can precipitate and exacerbate vulvar dermatoses. Cytotoxic chemotherapy, hormonal therapies, and local pelvic radiation therapy can lead to vulvar symptoms, and cancer treatment-induced vulvar conditions include graft-versus-host-disease and radiation dermatitis. There have also been reports of lichen sclerosus development or exacerbation secondary to hormonal therapy and immune checkpoint inhibitors, attributed to proposed hormonal and immunologic pathogenesis of lichen sclerosus. Early recognition and treatment of these conditions can significantly improve quality of life. In this review, we summarize the clinical features and management characteristics of six types of common vulvar dermatoses that may present in the oncologic patient.

Oral mucositis: Current knowledge and future directions

Oral mucositis secondary to head and neck chemoradiation displays a complex molecular pathogenesis involving epithelial and microvascular injury, release of pro-inflammatory cytokines, and host-microbiome communications. These processes lead to oxidative stress and the release of reactive oxygen species that stifle the structural integrity of the oral mucosa, with emergence of erosions and ulcers. The consequences are malnutrition, psychological/psychiatric symptoms, poor quality of life, and occurrence of opportunistic infections. The latter pose a major challenge due to the risk of interruption of anti-neoplastic therapy, tumour recurrence and, ultimately, death. This article aims to present the clinical characteristics, molecular pathogenesis, and an overview of the predisposing factors and current management of oral mucositis. It is anticipated that the future direction of the management of oral mucositis will focus on evidence-based prehabilitation and pre- and per-chemoradiation therapy monitoring.

New Insights into the Role of PD-1 and Its Ligands in Allergic Disease

Programmed cell death 1 (PD-1) and its ligands PD-L1 and PD-L2 are receptors that act in co-stimulatory and coinhibitory immune responses. Signaling the PD-1/PD-L1 or PD-L2 pathway is essential to regulate the inflammatory responses to infections, autoimmunity, and allergies, and it has been extensively studied in cancer. Allergic diseases include asthma, rhinoconjunctivitis, atopic dermatitis, drug allergy, and anaphylaxis. These overactive immune responses involve IgE-dependent activation and increased CD4+ T helper type 2 (Th2) lymphocytes. Recent studies have shown that PD-L1 and PD-L2 act to regulate T-cell activation and function. However, the main role of PD-1 and its ligands is to balance the immune response; however, the inflammatory process of allergic diseases is poorly understood. These immune checkpoint molecules can function as a brake or a kick-start to regulate the adaptive immune response. These findings suggest that PD-1 and its ligands may be a key factor in studying the exaggerated response in hypersensitivity reactions in allergies. This review summarizes the current understanding of the role of PD-1 and PD-L1 and PD-L2 pathway regulation in allergic diseases and how this immunomodulatory pathway is currently being targeted to develop novel therapeutic immunotherapy.

Oral Immune-Related Adverse Events - Current Concepts and their Management

Recent advent of immune checkpoint inhibitors (ICIs) have made significant improvement in the treatment outcome of cancer patients. They are also known to increase the overall survival in many malignancies. They target key immune checkpoints, acting on the cytotoxic T-lymphocyte antigen-4, programmed death-1 (PD-1), and PD-1 ligand 1 pathways. ICIs are effective in cancer therapy, but also possess various adverse effects that are termed together as immune-related adverse events (irAEs). Information focusing only on the oral reactions of irAEs is scanty in the literature. Therefore, we performed a computerized database search in PubMed and Google Scholar to identify and collect data regarding the oral adverse effects of ICIs. The early recognition of oral irAEs and appropriative intervention may help in improving the quality of life in patients. This paper presents a brief review of oral irAEs and their management.

Severe oral ulcerative and lichenoid lesions associated with adrenal insufficiency in a patient treated with nivolumab: Report of a case and review of literature

Nivolumab, an antibody against anti-programmed death type 1, has been used for treatment of advanced non-small cell lung cancer with improvement of overall survival. Usually, diarrhea, cutaneous rash, and pruritus are reported as the most common immune-related adverse effects of nivolumab therapy. Oral lesions and secondary adrenal insufficiency sometimes occur but usually are rare events. We report a case of a patient treated with nivolumab who then showed persistent oral ulcerative and lichenoid lesions, which were refractory to topical corticosteroids. The oral lesions were concomitant to nivolumab-induced adrenal insufficiency. These adverse events led to nivolumab discontinuation, which favored oral lesion healing and adrenal insufficiency remission. Through a brief review of the literature concerning nivolumab toxicity in the oral cavity, we discuss the clinical aspect and management of these lesions.

Cutaneous adverse events caused by immune checkpoint inhibitors

IMPORTANCE

Immune checkpoint inhibitors (ICIs) have emerged as active therapies for a variety of cancers. Cutaneous toxicities are common immune-related adverse events and patients will often be referred to dermatologists for evaluation.

OBSERVATIONS

Cutaneous adverse events to ICIs can have a variety of clinical presentations. Among the more common are eczematous, morbilliform, and lichenoid dermatoses, as well as vitiligo and pruritus. Less common adverse events include psoriasiform dermatoses, bullous disorders, and severe cutaneous adverse reactions, including Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms. Because of the immunologic mechanism of ICIs, there are also a variety of rheumatologic adverse reactions with cutaneous manifestations, such as scleroderma, dermatomyositis, cutaneous lupus erythematosus, and various vasculitides. These cutaneous reactions often respond to topical or systemic steroids, although specific toxicities may have alternative treatments available.

CONCLUSIONS AND RELEVANCE

As they become more widely prescribed, dermatologists will see an increasing number of patients with cutaneous adverse events caused by ICI therapies. Accurately diagnosing and treating these toxicities is paramount to achieving the most favorable outcomes for patients.

Oral manifestations of immune-related adverse events in cancer patients treated with immune checkpoint inhibitors

Immunotherapy with immune checkpoint inhibitors (ICIs) has transformed cancer treatment over the past decade, improving survival rates in numerous advanced cancers. Immune-related adverse events (irAEs) are common and can affect any organ system, with many of these toxicities being well-characterized with clear grading criteria and management approaches. There has been less emphasis on oral manifestations of irAEs. This review provides an overview of oral manifestations of irAEs, including mucosal and salivary gland toxicities, and proposes a grading system and management guidelines. irAEs are common treatment-related toxicities in patients treated with ICIs. Oral irAEs can range from asymptomatic white reticulations to life-threatening mucocutaneous reactions requiring aggressive management with corticosteroids and/or permanent discontinuation of ICIs. Oral healthcare providers should be prepared to identify and manage oral irAEs in collaboration with oncologists and other specialists.

Evaluating T-cell cross-reactivity between tumors and immune-related adverse events with TCR sequencing: pitfalls in interpretations of functional relevance

T-cell receptor sequencing (TCRseq) enables tracking of T-cell clonotypes recognizing the same antigen over time and across biological compartments. TCRseq has been used to test if cross-reactive antitumor T cells are responsible for development of immune-related adverse events (irAEs) following immune checkpoint blockade. Prior studies have interpreted T-cell clones shared among the tumor and irAE as evidence supporting this, but interpretations of these findings are challenging, given the constraints of TCRseq. Here we capitalize on a rare opportunity to understand the impact of potential confounders, such as sample size, tissue compartment, and collection batch/timepoint, on the relative proportion of shared T-cell clones between an irAE and tumor specimens. TCRseq was performed on tumor-involved and -uninvolved tissues, including an irAE, that were obtained throughout disease progression and at the time of rapid autopsy from a patient with renal cell carcinoma treated with programmed death-1 (PD-1) blockade. Our analyses show significant effects of these confounders on our ability to understand T-cell receptor overlap, and we present mitigation strategies and study design recommendations to reduce these errors. Implementation of these strategies will enable more rigorous TCRseq-based studies of immune responses in human tissues, particularly as they relate to antitumor T-cell cross-reactivity in irAEs following checkpoint blockade.

Reduced expression of programmed cell death 1 and programmed cell death ligand 1 in infiltrating inflammatory cells of lichen planus without administration of immune checkpoint inhibitors

Keratinocytes are the main targets of infiltrating T cells in the pathogenesis of lichen planus. However, the mechanisms of dense inflammatory infiltrates beneath the epidermis remain unknown. The aim of the present study was to clarify the roles of programmed cell death 1 (PD-1) and its ligand (PD-L1) in the pathogenesis of lichen planus. Immunohistochemistry of PD-1 and PD-L1 in 12 cases each of lichen planus and dermal-type erythema multiforme was performed. The expression of PD-1 and PD-L1 on infiltrating inflammatory cells, predominantly lymphocytes in lichen planus, was significantly less compared to that in dermal-type erythema multiforme. By dual immunofluorescence, the overlap between PD-1 and leukocyte common antigen, CD4, CD8, CD68, and factor XIIIa was limited and found in only a very small portion of lichen planus cells. Our data suggest that decreased expression of PD-1 and PD-L1 could play a role in accelerating inflammatory cell infiltration targeting the epidermis in the pathogenesis of lichen planus.

Oral Manifestations in Melanoma Patients Treated with Target or Immunomodulatory Therapies

BACKGROUND

BRAF (v-raf murine sarcoma viral oncogene homolog B1) and MEK (mitogen activated protein kinase) inhibitors, as well as immunotherapy against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death 1 (PD-1) receptor and its ligand (PD-L1), have shown good results in improving the disease-free survival of patients with metastatic melanoma (MM). The aim of this review is to summarize the main oral adverse events (oAEs) occurring in patients undergoing target or immunotherapy. We proposed two separate sections: oAEs during the treatment with (1) target therapies with BRAF and MEK inhibitors and tyrosine kinase inhibitors (gingival hyperplasia, pigmentation disorders, squamo-proliferative lesions) and (2) immunotherapies with CTLA-4 or PD1 inhibitors (lichenoid reactions, immuno-bullous reactions, xerostomia and other reactions). Adverse events frequently include oAEs, although these are often misdiagnosed and under-reported. Indeed, the oral cavity is not routinely evaluated during clinical practice. The symptomatology related to oAEs is significant since it may represent the first manifestation of a severe systemic reaction, possibly leading to difficulties in nutrition with a consequent impact on patients' quality of life. A careful examination of the oral cavity is recommended during the evaluation of oncologic patients in order to promptly detect the onset of new manifestations.

Immune-related cutaneous adverse events due to checkpoint inhibitors

OBJECTIVE

To familiarize the reader with the most common cutaneous adverse events with immune checkpoint inhibitors (CPIs) and their grading and treatment.

DATA SOURCES

Recent research articles, relevant review articles, and case series/reports in English from the PubMed database mostly, from 2010 onward.

STUDY SELECTIONS

Most data are from retrospective studies and case series. Older studies regarding the mechanism were included if they were of particular importance.

RESULTS

An understanding of this review should enable the reader to identify specific skin disorders in patients receiving immune CPIs, grade the adverse event, and be able to treat or refer the patient as needed.

CONCLUSION

Allergists/immunologists need to be familiar with these immune-related cutaneous adverse events because their incidence will increase with the ever-expanding use of CPIs and, in particular, because patients will certainly continue to be referred suspecting drug allergies.

The Clinical and Histopathological Features of Cutaneous Immune-Related Adverse Events and Their Outcomes

Immune checkpoint inhibitors (ICIs) cause a variety of inflammatory eruptions. The understanding of ICI-induced inflammatory eruptions with detailed histopathological findings is not adequate, particularly in Asian populations. In this study, we retrospectively reviewed 51 patients who were histopathologically diagnosed with cutaneous immune-related adverse events (irAEs) following ICI therapy between 2014 and 2020 at the Department of Dermatology of Kyushu University Hospital. Of the 51 patients (30 men, 21 women), maculopapular rash (38/51, 74.5%), erythema multiforme (2/51, 3.9%), lichenoid reaction (3/51, 5.9%), psoriasiform reaction (3/51, 5.9%), bullous pemphigoid (3/51, 5.9%), scleroderma-like reaction (1/51, 2.0%), and Stevens–Johnson syndrome (1/51, 2.0%) were observed. The clinical and histopathological findings of these eruptions were equivalent to typical cases of common drug eruptions. The onset of maculopapular rash was relatively early (more than half of events occurred within 1 month), whereas lichenoid reactions and autoimmune diseases occurred relatively late (4–8 months). With appropriate treatment and/or interruption of ICIs, most rashes improved (50/51, 98.0%). The ICI-induced inflammatory eruptions shared similar clinical and histopathological features with classical inflammatory eruptions, but a variety of inflammatory eruptions may occur with different degrees of severity. Dermatologists play an important role in providing specialized care for cutaneous irAEs.

Radiological imaging features of the salivary glands in xerostomia induced by an immune checkpoint inhibitor

The clinical features of xerostomia induced by immune checkpoint inhibitors (ICI) are similar to those of Sjögren’s syndrome (SS), whereas the immunohistological and serological features are known to differ from those of SS. However, the radiologic imaging features of salivary glands are not yet well known. We report a case of a 56-year-old male patient diagnosed with ICI-induced xerostomia. The patient underwent various imaging examinations to investigate the condition of the salivary glands, which indicated the following: (1) less specific findings on contrast-enhanced computed tomography, (2) mixed with intermediate and low signal intensity on both T₁-weighted and fat-suppressed T₂-weighted magnetic resonance imaging and poor “salt and pepper” appearance on magnetic resonance sialography, and (3) multiple ovoid hypoechoic areas with hyperechoic bands without acute sialadenitis on ultrasound. These radiologic imaging findings suggested remarkable lymphocyte infiltration, which could be a characteristic of ICI-induced xerostomia.

Evaluation of PD-L1, PD-L2, PD-1 and cytotoxic immune response in oral lichen planus

OBJECTIVE

To investigate the expression of programmed death-ligands 1 and 2 (PD-L1, PD-L2), programmed death-1 (PD-1), CD8 and granzyme B (GrB), as well as its correlation with the severity of oral lichen planus (OLP).

MATERIALS AND METHODS

In a collaborative study, 33 cases of OLP were evaluated according to the latest criteria proposed by the American Academy of Oral and Maxillofacial Pathology (AAOMP/2016) and were submitted to immunohistochemistry. Positivity was measured semiquantitatively (PD-L1, PD-L2) and quantitatively (PD-1, CD8, GrB). The severity of OLP was assessed according to clinical subtype, symptomatology and response to corticosteroid therapy.

RESULTS

Most OLPs were considered to be negative for PD-L1 (66.6%), but high expression of PD-L2 (96.9%) by keratinocytes and immunoinflammatory cells was observed. PD-1⁺ cell density/mm² was reduced compared to CD8⁺ cells. A low cytotoxic immune response (CD8:GrB ratio) was also demonstrated. Interestingly, there were fewer GrB⁺ cells in the intraepithelial region in reticular OLP compared to erosive/bullous OLP.

CONCLUSIONS

PD-L1/PD-1 pathways appear to be compromised in OLP due to low PD-L1 expression in most samples. In contrast, PD-L2 overexpression associated with a possible regulation of the cytotoxic immune response suggests an immune tolerance that may contribute to the chronic profile of OLP.

Multinational Association of Supportive Care in Cancer (MASCC) 2020 clinical practice recommendations for the management of severe dermatological toxicities from checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) frequently result in cutaneous immune-related adverse events (IrAEs). Although the majority of these events are mild-to-moderate in severity, up to 5% are severe, which may lead to morbidity and dose interruption or discontinuation of ICI therapy. In addition, up to 25% of dermatologic IrAEs are corticosteroid-refractory or corticosteroid-dependent. These 2020 MASCC recommendations cover the diagnosis and management of cutaneous IrAEs with a focus on moderate-to-severe and corticosteroid-resistant events. Although the usage of immune-suppressive therapy has been advocated in this setting, there is a lack of randomized clinical trial data to provide a compelling level of evidence of its therapeutic benefit.

Cutaneous Immune-Related Adverse Events (irAEs) to Immune Checkpoint Inhibitors: A Dermatology Perspective on Management [Formula: see text]

Immune checkpoint inhibitors have proven to be efficacious for a broad spectrum of solid organ malignancies. These monoclonal antibodies lead to cytotoxic T-cell activation and subsequent elimination of cancer cells. However, they can also lead to immune intolerance and immune-related adverse event (irAEs) that are new and specific to these therapies. Cutaneous irAEs are the most common, arising in up to 34% of patients on PD-1 inhibitors and 43% to 45% on CTLA-4 inhibitors. The most common skin manifestations include maculopapular eruption, pruritus, and vitiligo-like lesions. A grading system has been proposed, which guides management of cutaneous manifestations based on the percent body surface area (BSA) involved. Cutaneous irAEs may prompt clinicians to reduce drug doses, add systemic steroids to the regiment, and/or discontinue lifesaving immunotherapy. Thus, the goal is for early identification and concurrent management to minimize treatment interruptions. We emphasize here that the severity of the reaction should not be graded based on BSA involvement alone, but rather on the nature of the primary cutaneous pathology. For instance, maculopapular eruptions rarely affect <30% BSA and can often be managed conservatively with skin-directed therapies, while Stevens-Johnson syndrome (SJS) affecting even 5% BSA should be managed aggressively and the immunotherapy should be discontinued at once. There is limited literature available on the management of the cutaneous irAEs and most studies present anecdotal evidence. We review the management strategies and provide recommendations for psoriatic, immunobullous, maculopapular, lichenoid, acantholytic eruptions, vitiligo, alopecias, vasculitides, SJS/toxic epidermal necrolysis, and other related skin toxicities.

Immune checkpoint inhibitor-related dermatologic adverse events

Immune checkpoint inhibitors have emerged as a pillar in the management of advanced malignancies. However, nonspecific immune activation may lead to immune-related adverse events, wherein the skin and its appendages are the most frequent targets. Cutaneous immune-related adverse events include a diverse group of inflammatory reactions, with maculopapular rash, pruritus, psoriasiform and lichenoid eruptions being the most prevalent subtypes. Cutaneous immune-related adverse events occur early, with maculopapular rash presenting within the first 6 weeks after the initial immune checkpoint inhibitor dose. Management involves the use of topical corticosteroids for mild to moderate (grades 1-2) rash, addition of systemic corticosteroids for severe (grade 3) rash, and discontinuation of immunotherapy with grade 4 rash. Bullous pemphigoid eruptions, vitiligo-like skin hypopigmentation/depigmentation, and psoriasiform rash are more often attributed to programmed cell death-1/programmed cell death ligand-1 inhibitors. The treatment of bullous pemphigoid eruptions is similar to the treatment of maculopapular rash and lichenoid eruptions, with the addition of rituximab in grade 3-4 rash. Skin hypopigmentation/depigmentation does not require specific dermatologic treatment aside from photoprotective measures. In addition to topical corticosteroids, psoriasiform rash may be managed with vitamin D₃ analogues, narrowband ultraviolet B light phototherapy, retinoids, or immunomodulatory biologic agents. Stevens-Johnson syndrome and other severe cutaneous immune-related adverse events, although rare, have also been associated with checkpoint blockade and require inpatient care as well as urgent dermatology consultation.

Dermatologic toxicities to immune checkpoint inhibitor therapy: A review of histopathologic features

Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal antibodies that block cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1, or programmed cell death ligand 1 show improved and sustained responses in patients with cancer. However, these agents are associated with a plethora of adverse events, many manifesting in the skin. As the clinical application of cancer immunotherapies expands, understanding the clinical and histopathologic features of associated cutaneous toxicities becomes increasingly important to dermatologists, oncologists, and pathologists to ensure timely diagnosis and appropriate care. This review discusses cutaneous reactions to immune checkpoint inhibitors, focusing on histopathologic features.

Cutaneous adverse reactions to anti-PD-1 treatment-A systematic review

The use of the humanized monoclonal anti-programmed cell death 1 antibodies pembrolizumab and nivolumab as potent anticancer therapies is rapidly increasing. However, since their approval, numerous cases of cutaneous reactions have been reported. Cutaneous adverse reactions to these agents have yet to be fully characterized and range from nonspecific eruptions to recognizable skin manifestations, which may be localized and vary from mild to life threatening. This systematic review article provides an overview of the various adverse cutaneous reactions to pembrolizumab and nivolumab therapy and offers suggestions for their management.