Analysis of Immunologic Function Changes in Lichen Planus After Clinical Treatment

PD-1 Inhibitor Induced Hypertrophic Lichen Planus: A Case Report

BACKGROUND AND OBJECTIVE

PD-1 inhibitors have revolutionized cancer therapies and are being used to treat an expanding array of cancers. To best serve patients, clinicians should be familiar with the spectrum of skin manifestations associated with PD-1 inhibitor therapy. Here, we report a unique case of hypertrophic lichen planus (HLP) in a 64-year-old man treated with pembrolizumab; the presentation initially suggested a squamous cell carcinoma (SCC) morphology, then evolved into a morphology more typical of hypertrophic lichen planus. This case underscores the need for caution in diagnosing eruptive SCCs associated with PD-1 inhibitor therapy. In such instances, maintaining a high suspicion for lichenoid reactions as sequelae of PD-1 inhibitor treatment and starting an empiric trial of therapy for lichenoid dermatitis may be warranted to ensure timely management of lesions.

METHODS

We describe a case of hypertrophic lichen planus mimicking squamous cell carcinoma in the setting of PD-1 inhibitory therapy with pembrolizumab. A PubMed literature review was conducted to identify other cases and determine the incidence of lichenoid reactions imitating squamous cell carcinoma in the setting of PD-1 inhibitor use.

RESULTS

Our case is one of the few available pieces of literature describing eruptive hypertrophic lichen planus imitating SCC in the setting of PD-1 inhibitor use. Initial skin nodule biopsy appeared histologically compatible with squamous cell carcinoma. Repeat biopsy of the skin lesions revealed histological features consistent with hypertrophic lichen planus. Over time, lower extremity lesions evolved into a more typical appearance of hypertrophic lichen planus. Treatment with topical 0.05% clobetasol ointment and oral acitretin 25 mg led to complete resolution of lesions within 2-3 months.

CONCLUSIONS

This case underscores the significance of maintaining vigilance for lichenoid reactions as potential sequelae of PD-1 inhibitor therapy. It highlights the variability in initial presentation and the potential for lesions to transform over time. Timely recognition and appropriate management, including high-potency topical corticosteroids and oral acitretin, are crucial for achieving favorable outcomes in patients experiencing such reactions. More studies are necessary to fully analyze the rate of HLP occurrence as a consequence of PD-1 inhibitor use.

Levamisole suppresses activation and proliferation of human T cells by the induction of a p53-dependent DNA damage response

Levamisole (LMS) is a small molecule used in the treatment of idiopathic nephrotic syndrome (INS). The pathogenesis of INS remains unknown, but evidence points toward an immunological basis of the disease. Recently, LMS has been shown to increase the relapse-free survival in INS patients. While LMS has been hypothesized to exert an immunomodulatory effect, its mechanism of action remains unknown. Here, we show that LMS decreased activation and proliferation of human T cells. T-cell activation-associated cytokines such as IL-2, TNF-α, and IFN-γ were reduced upon LMS treatment, whereas IL-4 and IL-13 were increased. Gene expression profiling confirmed that the suppressive effects of LMS as genes involved in cell cycle progression were downregulated. Furthermore, genes associated with p53 activation were upregulated by LMS. In agreement, LMS treatment resulted in p53 phosphorylation and increased expression of the p53 target gene FAS. Accordingly, LMS sensitized activated T cells for Fas-mediated apoptosis. LMS treatment resulted in a mid-S phase cell cycle arrest accompanied by γH2AX-foci formation and phosphorylation of CHK1. Our findings indicate that LMS acts as an immunosuppressive drug that directly affects the activation and proliferation of human T cells by induction of DNA damage and the activation of a p53-dependent DNA damage response.

The potential roles of Th17 cells in the pathogenesis of oral lichen planus

BACKGROUND

Oral lichen planus (OLP) is a T cell-mediated chronic autoimmune disease, whose pathogenesis and etiology are not entirely understood. OLP is characterized by subepithelial lymphocyte infiltration and elevated intra-epithelial lymphocytes. The majority of lamina propria lymphocytes are CD4⁺ T cells. CD4⁺ helper T (Th) cells play a crucial role in activating CD8⁺ cytotoxic T cells (CTLs) through interactions and cytokine production. Th1 and Th2 cells are well-accepted to be associated with OLP pathogenesis. However, OLP treatment is challenging yet, the more information we have about the pathology of OLP, the easier it will be treated. With the discovery of Th17 cells in recent years and the demonstration of their role in autoimmune disease, many researchers started to investigate the role of Th17 in the pathogenesis of OLP.

METHODS

To make up this review, studies covering the role of TH17 in different types of lichen planus were selected from major databases.

RESULTS

As we review in this article, Th17 cells and their signature cytokines play an important role in OLP pathogenesis. As well, utilizing some anti-IL-17 antibodies showed promising results in improving the disease; however, more studies are still needed to better understand and treat OLP.

Levamisole in Children with Idiopathic Nephrotic Syndrome: Clinical Efficacy and Pathophysiological Aspects

Steroid sensitive nephrotic syndrome is one of the most common pediatric glomerular diseases. Unfortunately, it follows a relapsing and remitting course in the majority of cases, with 50% of all cases relapsing once or even more often. Most children with idiopathic nephrotic syndrome respond initially to steroid therapy, nevertheless repeated courses for patients with relapses induce significant steroid toxicity. Patients with frequent relapses or steroid dependency thus require alternative treatment, such as cyclophosphamide, cyclosporine, tacrolimus, mycophenolate mofetil, levamisole, or rituximab. To reduce the relapse rate, several drugs have been used. Among these, levamisole has been considered the least toxic and least expensive therapy. Several randomized controlled trials (RCT) showed that levamisole is effective in reducing the relapse risk in steroid sensitive forms of nephrotic syndrome with a low frequency of side effects. Levamisole is a synthetic imidazothiazole derivative with immune-modulatory properties. In this article, we review recent data from randomized trials and observational studies to assess the efficacy of levamisole in frequently relapsing nephrotic syndrome and steroid-dependent nephrotic syndrome.