UNASSIGNED: To evaluate the risk of neutropenia during treatment with anti-IL-23 antibodies in patients with psoriasis.
UNASSIGNED: We conducted an observational study with cohort design using MID-NET® in Japan. We identified patients with psoriasis who were newly prescribed anti-IL-23 antibodies, anti-IL-17-antibodies, adalimumab, or apremilast between January 1, 2009, and March 31, 2021. We estimated the adjusted hazard ratio (aHR) of anti-IL-23 antibodies compared to that of anti-IL-17 antibodies, adalimumab, or apremilast, for the risk of grade 2 (neutrophil count < 1,500/μL) or grade 3 (neutrophil count < 1,000/μL) neutropenia.
UNASSIGNED: Overall, 287 patients on anti-IL-23 antibodies, 189 patients on anti-IL-17 antibodies, 293 patients on adalimumab, and 540 patients on apremilast were included. Compared with anti-IL-17 antibodies, the aHR (95% confidence interval (CI)) of anti-IL-23 antibodies was 0.83 (0.27-2.51) for grade 2 and 0.40 (0.02-7.60) for grade 3 neutropenia; that when compared with adalimumab was 0.76 (0.28-2.06) for grade 2 but was not calculated for grade 3 as no cases were found; and that compared with apremilast was 3.88 (0.62-24.48) for grade 2 and 0.43 (0.02-11.63) for grade 3 neutropenia.
UNASSIGNED: No clear increase in the risk of neutropenia with anti-IL-23 antibodies was observed.

B cells and T cells collaborate in multiple sclerosis (MS) pathogenesis. IgH[MOG] mice possess a B cell repertoire skewed to recognize myelin oligodendrocyte glycoprotein (MOG). Here, we show that upon immunization with the T cell-obligate autoantigen, MOG[35-55], IgH[MOG] mice develop rapid and exacerbated experimental autoimmune encephalomyelitis (EAE) relative to wildtype (WT) counterparts, characterized by aggregation of T and B cells in the IgH[MOG] meninges and by CD4+ T helper 17 (Th17) cells in the CNS. Production of the Th17 maintenance factor IL-23 is observed from IgH[MOG] CNS-infiltrating and meningeal B cells, and in vivo blockade of IL-23p19 attenuates disease severity in IgH[MOG] mice. In the CNS parenchyma and dura mater of IgH[MOG] mice, we observe an increased frequency of CD4+PD-1+CXCR5- T cells that share numerous characteristics with the recently described T peripheral helper (Tph) cell subset. Further, CNS-infiltrating B and Tph cells from IgH[MOG] mice show increased reactive oxygen species (ROS) production. Meningeal inflammation, Tph-like cell accumulation in the CNS and B/Tph cell production of ROS were all reduced upon p19 blockade. Altogether, MOG-specific B cells promote autoimmune inflammation of the CNS parenchyma and meninges in an IL-23-dependent manner.

Psoriasis is an inflammatory disease with systemic manifestations that most commonly presents as itchy, erythematous, scaly plaques on extensor surfaces. Activation of the IL-23/IL-17 pro-inflammatory signaling pathway is a hallmark of psoriasis and its inhibition is key to clinical management. Granzyme K (GzmK) is an immune cell-secreted serine protease elevated in inflammatory and proliferative skin conditions. In the present study, human psoriasis lesions exhibited elevated GzmK levels compared to non-lesional psoriasis and healthy control skin. In an established murine model of imiquimod (IMQ)-induced psoriasis, genetic loss of GzmK significantly reduced disease severity, as determined by delayed plaque formation, decreased erythema and desquamation, reduced epidermal thickness, and inflammatory infiltrate. Molecular characterization in vitro revealed that GzmK contributed to macrophage secretion of IL-23 as well as PAR-1-dependent keratinocyte proliferation. These findings demonstrate that GzmK enhances IL-23-driven inflammation as well as keratinocyte proliferation to exacerbate psoriasis severity.

Psoriasis is an immune-mediated skin disease associated with neurogenic inflammation, but the underlying molecular mechanism remains unclear. We demonstrate here that acid-sensing ion channel 3 (ASIC3) exacerbates psoriatic inflammation through a sensory neurogenic pathway. Global or nociceptor-specific Asic3 knockout (KO) in female mice alleviates imiquimod-induced psoriatic acanthosis and type 17 inflammation to the same extent as nociceptor ablation. However, ASIC3 is dispensable for IL-23-induced psoriatic inflammation that bypasses the need for nociceptors. Mechanistically, ASIC3 activation induces the activity-dependent release of calcitonin gene-related peptide (CGRP) from sensory neurons to promote neurogenic inflammation. Botulinum neurotoxin A and CGRP antagonists prevent sensory neuron-mediated exacerbation of psoriatic inflammation to similar extents as Asic3 KO. In contrast, replenishing CGRP in the skin of Asic3 KO mice restores the inflammatory response. These findings establish sensory ASIC3 as a critical constituent in psoriatic inflammation, and a promising target for neurogenic inflammation management.

Interleukin (IL-)23 is a major mediator and therapeutic target in chronic inflammatory diseases that also elicits tissue protection in the intestine at homeostasis or following acute infection1-4. However, the mechanisms that shape these beneficial versus pathological outcomes remain poorly understood. To address this gap in knowledge, we performed single-cell RNA sequencing on all IL-23 receptor-expressing cells in the intestine and their acute response to IL-23, revealing a dominance of T cells and group 3 innate lymphoid cells (ILC3s). Unexpectedly, we identified potent upregulation of the immunoregulatory checkpoint molecule cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) on ILC3s. This pathway was activated by gut microbes and IL-23 in a FOXO1- and STAT3-dependent manner. Mice lacking CTLA-4 on ILC3s exhibited reduced regulatory T cells, elevated inflammatory T cells and more-severe intestinal inflammation. IL-23 induction of CTLA-4+ ILC3s was necessary and sufficient to reduce co-stimulatory molecules and increase PD-L1 bioavailability on intestinal myeloid cells. Finally, human ILC3s upregulated CTLA-4 in response to IL-23 or gut inflammation and correlated with immunoregulation in inflammatory bowel disease. These results reveal ILC3-intrinsic CTLA-4 as an essential checkpoint that restrains the pathological outcomes of IL-23, suggesting that disruption of these lymphocytes, which occurs in inflammatory bowel disease5-7, contributes to chronic inflammation.

UNASSIGNED: Treatment options with disease-modifying antirheumatic drugs (DMARDs) for psoriatic arthritis (PsA) have evolved over recent years. In addition to Janus kinase inhibitors (JAKi), four classes of biologic DMARDs (bDMARDs; interleukin [IL]-23 inhibitors [IL-23i], IL-12/23 inhibitors [IL-12/23i], tumor necrosis factor inhibitors [TNFi], and IL-17 inhibitors [IL-17i]) are currently approved for moderate to severe PsA treatment. There is minimal evidence of the persistence of these drugs among PsA outpatients in a real-world scenario during the period following the approval of JAKi. Therefore, we aimed to analyze the drug survival rates of biologic and JAKi therapies among German PsA outpatients during routine clinical care.
UNASSIGNED: We retrospectively analyzed PsA patients with a new prescription for a biologic or JAKi in the RHADAR database between January 2015 and October 2023. Kaplan-Meier Curves and Cox regression modelling were used to compare drug survival rates.
UNASSIGNED: 1352 new prescriptions with bDMARDs (IL-12/23i [n=50], IL-23i [n=31], TNFi [n=774], IL-17i [n=360]) or JAKi (n=137) were identified. The 5-year drug survival rate was 67.8% for IL-17i, 62.3% for TNFi, 53.3% for JAKi, and 46.0% for IL-12/23i. Discontinuation probabilities for JAKi and IL-12/23i were significantly higher compared with TNFi (JAKi hazard ratio [HR] 1.66, [95% CI 1.23-2.24], p=0.001; IL-12/23i HR 1.54, [95% CI 1.02-2.33], p=0.042) and IL-17i (JAKi HR 1.77, [95% CI 1.27-2.47], p=0.001; IL-12/23i HR 1.64, [95% CI 1.06-2.55], p=0.027). JAKi-treated patients had more severe disease and more osteoarthritis (OA) compared to TNFi and more OA compared to IL-17i.
UNASSIGNED: German PsA outpatients might persist longer with TNFi and IL-17i compared with IL-12/23i or JAKi. For TNFi, differences in subgroup characteristics and comorbidities (OA) may have affected drug survival rates. For IL-17i, the longer drug survival might not only be related to less OA compared to JAKi and, therefore, might be affected by other factors.

Pityriasis rubra pilaris (PRP) is a rare and chronic inflammatory dermatologic condition characterized by hyperkeratotic salmon-colored plaques and palmoplantar keratoderma. Traditional therapeutic modalities have shown limited efficacy and often entail potential adverse effects, highlighting the need for alternative treatment options. Our review aims to summarize the current evidence on the off-label use of IL-23 inhibitors, risankizumab and guselkumab, in the treatment of PRP. These biologic agents have been approved for psoriasis, and their potential role in managing PRP has recently garnered interest. We conducted a comprehensive literature search on PubMed and Scopus databases, identifying relevant studies published in English up to June 2023 following PRISMA guidelines. A total of 10 studies were selected for data extraction and review. Results from the selected studies demonstrated encouraging outcomes with both risankizumab and guselkumab in managing PRP. Among 11 patients treated with risankizumab, 10 showed notable improvements in various disease manifestations, including pruritus, erythema, and affected body surface area. DLQI scores and BSA percentages reported a significant improvement before and after risankizumab treatment (p = 0.0322; p = 0.0216). However, two cases also reported symptom aggravation or even disease worsening. Patients treated with guselkumab exhibited ultimate improvement in all five cases, with complete clearance in three out of five cases. DLQI and BSA percentages also reported significant improvement with treatment with guselkumab (p = 0.0172; p < 0.0001). While most cases demonstrated positive outcomes, there were isolated instances of worsening symptoms, emphasizing the need for caution and further investigation. Further research with larger sample sizes and longer follow-up periods is necessary to establish the efficacy, optimal dosing, and long-term safety of risankizumab and guselkumab in treating PRP. Overall, we provide valuable insights into the potential use of IL-23 inhibitors, risankizumab, and guselkumab, as promising treatment options for PRP. These biologics have shown efficacy in improving symptoms in treatment-resistant cases, offering new avenues for clinicians to explore in the treatment of PRP.

Increasing rates of autoimmune and inflammatory disease present a burgeoning threat to human health1. This is compounded by the limited efficacy of available treatments1 and high failure rates during drug development2, highlighting an urgent need to better understand disease mechanisms. Here we show how functional genomics could address this challenge. By investigating an intergenic haplotype on chr21q22-which has been independently linked to inflammatory bowel disease, ankylosing spondylitis, primary sclerosing cholangitis and Takayasu\'s arteritis3-6-we identify that the causal gene, ETS2, is a central regulator of human inflammatory macrophages and delineate the shared disease mechanism that amplifies ETS2 expression. Genes regulated by ETS2 were prominently expressed in diseased tissues and more enriched for inflammatory bowel disease GWAS hits than most previously described pathways. Overexpressing ETS2 in resting macrophages reproduced the inflammatory state observed in chr21q22-associated diseases, with upregulation of multiple drug targets, including TNF and IL-23. Using a database of cellular signatures7, we identified drugs that might modulate this pathway and validated the potent anti-inflammatory activity of one class of small molecules in vitro and ex vivo. Together, this illustrates the power of functional genomics, applied directly in primary human cells, to identify immune-mediated disease mechanisms and potential therapeutic opportunities.

The hallmarks of spondyloarthritis (SpA) are type 3 immunity-driven inflammation and new bone formation (NBF). Macrophage migration inhibitory factor (MIF) was found to be a key driver of the pathogenesis of SpA by amplifying type 3 immunity, yet MIF-interacting molecules and networks remain elusive. Herein, we identified hypoxia-inducible factor-1 alpha (HIF1A) as an interacting partner molecule of MIF that drives SpA pathologies, including inflammation and NBF. HIF1A expression was increased in the joint tissues and synovial fluid of SpA patients and curdlan-injected SKG (curdlan-SKG) mice compared to the respective controls. Under hypoxic conditions in which HIF1A was stabilized, human and mouse neutrophils exhibited substantially increased expression of MIF and IL-23, an upstream type 3 immunity-related cytokine. Similar to MIF, systemic overexpression of IL-23 induced SpA pathology in SKG mice, while the injection of a HIF1A-selective inhibitor (PX-478) into curdlan-SKG mice prevented or attenuated SpA pathology, as indicated by a marked reduction in the expression of MIF and IL-23. Furthermore, genetic deletion of MIF or HIF1A inhibition with PX-478 in IL-23-overexpressing SKG mice did not induce evident arthritis or NBF, despite the presence of psoriasis-like dermatitis and blepharitis. We also found that MIF- and IL-23-expressing neutrophils infiltrated areas of the NBF in curdlan-SKG mice. These neutrophils potentially increased chondrogenesis and cell proliferation via the upregulation of STAT3 in periosteal cells and ligamental cells during endochondral ossification. Together, these results provide supporting evidence for an MIF/HIF1A regulatory network, and inhibition of HIF1A may be a novel therapeutic approach for SpA by suppressing type 3 immunity-mediated inflammation and NBF.

HLA-B27 is a major risk factor for spondyloarthritis (SpA), yet the underlying mechanisms remain unclear. HLA-B27 misfolding-induced IL-23, which is mediated by endoplasmic reticulum (ER) stress has been hypothesized to drive SpA pathogenesis. Expression of HLA-B27 and human β2m (hβ2m) in rats (HLA-B27-Tg) recapitulates key SpA features including gut inflammation. Here we determined whether deleting the transcription factor CHOP (Ddit3-/-), which mediates ER-stress induced IL-23, affects gut inflammation in HLA-B27-Tg animals. ER stress-mediated Il23a overexpression was abolished in CHOP-deficient macrophages. Although CHOP-deficiency also reduced Il23a expression in immune cells isolated from the colon of B27+ rats, Il17a levels were not affected, and gut inflammation was not reduced. Rather, transcriptome analysis revealed increased expression of pro-inflammatory genes, including Il1a, Ifng and Tnf in HLA-B27-Tg colon tissue in the absence of CHOP, which was accompanied by higher histological Z-scores. RNAScope localized Il17a mRNA to the lamina propria of the HLA-B27-Tg rats and revealed similar co-localization with Cd3e (CD3) in the presence and absence of CHOP. This demonstrates that CHOP-deficiency does not improve, but rather exacerbates gut inflammation in HLA-B27-Tg rats, indicating that HLA-B27 is not promoting gut disease through ER stress-induced IL-23. Hence, CHOP may protect rats from more severe HLA-B27-induced gut inflammation.