Bhullar, Puneet

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 IFN-γ, a cytokine implicated in the pathogenesis of LP. METHODS In this phase II trial, 12 patients with cutaneous LP received 2 mg daily baricitinib for 16 weeks, accompanied by in-depth spatial, single-cell, and bulk transcriptomic profiling of pre- and posttreatment 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 + , and CXCL13 + cytotoxic T cell population in LP skin and demonstrated a rapid decrease in IFN signature within 2 weeks of treatment, most prominently in the basal layer of the epidermis. CONCLUSION This study demonstrates the efficacy and molecular mechanisms of JAK inhibition in LP. TRIAL REGISTRATION NCT05188521 FUNDING Eli Lilly, Appignani Benefactor Funds, 5P30AR075043, Mayo Clinic Clinical Trials Stimulus Funds.

AbstractChimeric antigen receptor (CAR) T‐cell therapy has demonstrated remarkable success in treating various B‐cell malignancies, redirecting T‐cell cytotoxicity toward cancer cells. Despite its efficacy, CAR‐T therapy is associated with potential risks, including cytokine release syndrome (CRS) and cytopenia. We present a case of a 69‐year‐old man with diffuse large B‐cell lymphoma treated with axicabtagene‐ciloleucel CAR‐T therapy, who developed a rare and severe cutaneous toxicity resembling toxic epidermal necrolysis (TEN). The patient exhibited persistent fevers, CRS, and subsequent development of a widespread erythematous macular eruption, progressing to vesiculation with bullae. Notably, allopurinol‐induced TEN was considered with the patient's recent exposure to allopurinol, although the onset and minimal mucosal involvement did not align with typical presentations of allopurinol‐induced cases. The cutaneous reaction, distinct from typical SJS/TEN, showed minimal mucosal involvement and coincided with the cytokine release storm, differing from allopurinol‐induced TEN. Despite the absence of guidelines, the patient was managed with systemic steroids, achieving significant improvement. This case expands the spectrum of CAR‐T therapy‐related cutaneous toxicities, highlighting the need for early recognition of histopathology and tailored management by dermatologists. Further understanding of these reactions is crucial for optimizing the safety profile of this groundbreaking immunotherapy.

This case report highlights a severe eczematous rash manifesting broadly across the scalp, face, and neck of a 54-year-old female following a resolved herpes zoster infection. Notably, such cutaneous reactions post-varicella zoster virus infection, which may present weeks to years after the acute phase, have been documented but remain poorly understood in their pathogenesis. This patient exhibited a blistering rash diagnosed as shingles with overlying cellulitis, initially treated with valacyclovir and cefalexin. Upon returning with a diffuse rash post-treatment, further examination and tests led to a differential diagnosis that most closely aligned with eczema exacerbation with superimposed bacterial infection, confirmed by the presence of methicillin-resistant Staphylococcus aureus. Treatment encompassed intravenous vancomycin, ciprofloxacin eye drops, topical hydrocortisone, betamethasone lotion, and gabapentin, leading to substantial improvement. This case underscores the complexity of diagnosing and managing cutaneous reactions post-varicella zoster virus infection and suggests a multimodal treatment approach may yield favorable outcomes.

AbstractBackgroundPrevious literature on cutaneous squamous cell carcinoma (cSCC) suggests that the incidence, rate of metastasis, and tumour severity of cSCC are higher in immunosuppressed patients than in immunocompetent patients. However, current literature lacks an extensive comparison of cSCC clinical characteristics and outcomes in immunosuppressed patients.ObjectivesWe compared cSCC tumour characteristics and disease‐related outcomes to help guide the clinical management of immunosuppressed patients.MethodsWe conducted a retrospective review of histopathologic and clinical data from 935 cSCC cases (19.5% immunosuppressed) from the Mayo Clinic.ResultsImmunosuppression was associated with younger age (69.3 vs. 74.8 years old, p < 0.0001), male gender (78.6% vs. 67.2%, p = 0.003), and higher grade cSCC tumour characterized by moderate or poor differentiation (25.7% vs. 15.8%, p = 0.009; 9.2% vs. 7.2%, p = 0.009, respectively). No significant differences were found in other tumour characteristics, including clinical tumour dimension, Brigham and Women's Hospital tumour staging or cumulative risk of metastasis and recurrence. Immunosuppressed patients had an increased risk of disease‐specific death on univariate analysis (hazard ratio [HR] [95% confidence interval, CI] 2.05 [1.13–3.74], p = 0.0128). Overall survival in the immunosuppressed population was worse (adjusted HR [95% CI] 1.83 [1.42–2.35], p < 0.001) and, notably, solid organ transplant recipients had the lowest overall survival when stratifying immunosuppressed patients by immunosuppression type (HR [95% CI] 1.62 [1.17–2.24], p < 0.0001).ConclusionsIn our study, immunosuppression status was predictive of poor differentiation of tumours and a reduction in overall and cSCC‐specific survival. Current staging systems for cSCC do not include immunosuppression as a risk factor and incorporating immune status may be beneficial for accurate risk stratification.

AbstractBackgroundPrimary cutaneous B‐cell lymphoma (PCBCL) is a group of B‐cell lymphomas of the skin containing primary cutaneous follicle centre lymphoma (PCFCL) and marginal zone B‐cell lymphoma/lymphoproliferative disorder (PCMZL), which are indolent, and diffuse large B‐cell lymphoma, leg type (PCDLBCL‐LT), which is aggressive.ObjectivesTo evaluate treatment outcomes between PCBCL subtypes after treatment with rituximab and to compare the efficacy of intralesional against systemic rituximab in indolent subtypes.MethodsA search for patients diagnosed with PCBCL and treated with rituximab (systemic or intralesional) across all Mayo Clinic sites was performed, yielding 39 patients.ResultsEight patients had PCFCL (six treated intralesionally and two systemically), 11 had PCMZL (four intralesional, eight systemic with one dual‐treated) and 20 had PCDLBCL‐LT (all systemic). The average age at diagnosis was 62.1 years (SD = 15.1), with average follow‐up of 1852.6 days (SD = 1473.2). 69.2% of all patients treated with any form of rituximab experienced a complete response (100% PCFCL, 81.8% PCMZL and 50% PCDLBCL‐LT). When comparing all three subtypes, a significant difference was seen in overall treatment response (p = 0.022), and progressive disease rates (p = 0.015), but not in retreatment with rituximab (p = 0.440), time to retreatment (p = 0.757), recurrence (p = 0.907) or survival (p = 0.093). In the indolent subtypes, no difference in overall treatment response (p = 1.000), progressive disease rates (p = 1.000), recurrence (p = 0.650), rituximab retreatment (p = 0.650) or time to retreatment (p = 0.724) was observed.ConclusionsThis study suggests that rituximab, as systemic therapy and intralesional therapy, is effective in the management of PCBCL, and that intralesional therapy should be considered before more aggressive therapy in indolent disease.

AbstractBackgroundNecrobiosis lipoidica (NL) is complicated by ulceration in up to 35% of cases.MethodsRetrospective study of patients with NL seen at our institution between January 1, 1992, and May 25, 2021, was conducted. Ulcerated NL (UNL, n = 83) and non‐ulcerated NL (NUNL, n = 233) groups were compared.ResultsTwenty‐six percent (83/316) of patients with NL experienced ulceration. UNL was significantly more likely to be painful (52% vs. 36%, P = 0.01), was more likely to have a lesion‐associated cutaneous malignancy (7% vs. 0%, P < 0.001), and had a larger median size (7 vs. 5 cm, P = 0.004) compared to NUNL. Vascular studies were performed on a subset of patients and revealed transcutaneous oxygen pressure (TcPO2) < 40 mm Hg in 53% and venous insufficiency in 62% with no significant differences between UNL and NUNL groups. In patients with unilateral ulceration, mean TcPO2 values (39.7 vs. 46.6 mm Hg), regional perfusion index <0.6 (29% vs. 14%), and TcPO2 < 40 mm Hg (43% vs. 14%) were worse in the ulcerated leg compared to the non‐ulcerated leg, but these differences were not statistically significant.ConclusionsUNL was more likely to be painful, develop lesion‐associated malignancy, and be larger in size compared to NUNL. There were no statistically significant differences in venous insufficiency, arterial Doppler/ankle brachial index, or TcPO2 values between UNL and NUNL patients, however, a significant portion of the cohort demonstrated abnormal vascular studies, particularly on TcPO2 and venous insufficiency testing.

Abstract Background The pathogenesis of pityriasis rubra pilaris (PRP) is not completely understood, but interleukin (IL)-17 has been shown to play a critical role. There are no reliable immunomodulatory agents to treat PRP. We conducted an open-label, single-arm clinical trial of secukinumab, a monoclonal antibody that inhibits IL-17A, for the treatment of PRP. Objectives To evaluate the clinical efficacy of secukinumab and define the transcriptomic landscape of PRP and its response to IL-17A blockade. Methods Twelve patients with PRP were recruited for an open-label trial of secukinumab. Patients received a 24-week course of secukinumab. The primary endpoint was a ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) from baseline to week 28. Secondary endpoints included PASI 90, change in Physician’s Global Assessment (PGA), and change in Dermatology Life Quality Index (DLQI). RNA sequencing was performed on lesional and nonlesional skin biopsies obtained at baseline and week 2. Sample groups were compared to identify differential gene expression and pathway enrichment. This trial was registered with ClinicalTrials.gov: ‘Cosentyx (secukinumab) for the treatment of adult onset pityriasis rubra pilaris’ – NCT03342573. Results At week 28, six of 11 patients (55%) achieved PASI 75, and three patients (27%) achieved PASI 90. PGA (P = 0.008) and DLQI scores (P = 0.010) showed significant improvement with treatment. No serious treatment-related adverse events were encountered. Treatment with secukinumab normalized transcriptional differences between lesional and nonlesional skin. Transcriptomic data from nonresponsive patients suggest that overactivity of innate immune pathways may be driving resistance to secukinumab. Conclusions Secukinumab appears to be an effective treatment for PRP and warrants further investigation. PRP is a transcriptionally heterogeneous disease, reflecting its variable response to therapy. Agents targeting other IL-17 isoforms and innate immune mediators should be considered for future clinical trials. What is already known about this topic? The pathogenesis of pityriasis rubra pilaris is incompletely understood. Successful treatment has been reported with a variety of immunomodulatory agents, but disease is often refractory to therapy.Interleukin (IL)-17 is thought to drive keratinocyte proliferation and vascular dysfunction in this disease.A previous trial demonstrated efficacy of the anti-IL-17A drug ixekizumab for pityriasis rubra pilaris. What does this study add? Herein we describe the findings of a clinical trial of secukinumab, an anti-IL-17A monoclonal antibody, for the treatment of pityriasis rubra pilaris.Secukinumab was effective in treating pityriasis rubra pilaris.Our transcriptomic data give new insight into the expressional changes that occur in response to secukinumab and suggest mechanisms of treatment resistance.

AbstractBackgroundNecrobiosis lipoidica (NL) is an uncommon granulomatous dermatosis that can occur in patients with or without associated diabetes mellitus (DM). Prior studies have attempted to determine distinctive histopathologic features of NL in patients with and without DM.MethodsA retrospective review of 97 patients with NL was performed to determine the similar and distinctive histopathologic features in patients with DM and without DM.ResultsOf the 97 patients, 32% (n = 31) had DM. Epidermal acanthosis was seen more commonly in diabetics than nondiabetics (32.3% vs. 12.1%; p = 0.017). Naked (sarcoidal/tuberculoid) granulomas were more frequently observed in nondiabetics than diabetics (22.7% vs. 3.2%; p = 0.016). Eosinophils were more common in nondiabetics than diabetics (38.5% vs. 9.7%; p = 0.004), while neutrophilic infiltration was more common in diabetics than nondiabetics (45.2% vs. 17.5%; p = 0.004).ConclusionsThis study corroborates well‐documented histopathologic features of NL and shows distinctive histopathologic features of NL among patients with DM‐I, DM‐II, and without DM. These results support the hypothesis that there are different underlying drivers of NL between diabetics and nondiabetics.

Abstract The role of the human immune system as a factor in the aging process has led to extensive research in the field of infection biology and bioinformatics. Cell-based mathematical models have previously been used to simulate the immune system in response to pathogens. A variety of cells, such as activated and resting macrophages, plasma cells, antibodies, helper T cells, T-lymphocytes, and B-lymphocytes, have already been simulated by mathematical models. This work aims to incorporate cytokines in these mathematical models to create a more comprehensive simulation that can predict cytokine levels in response to a Gram-positive bacterium, S. aureus. To accomplish this, the cytokines Tumor Necrosis Factor Alpha (TNF-α), Interleukin 6 (IL-6), Interleukin 8 (IL-8), and Interleukin 10 (IL-10) were studied to quantify the relationship between cytokine release from macrophages and the concentration of the pathogen, S. aureus ex vivo. The results of the simulation were compared to ex vivo human whole blood data to test its accuracy. The future expansion of this model may provide a clearer image of the various interactions within the immune system and this improved model of the immune system may also facilitate a better understanding of the mechanisms that lead to the degradation of the immune system during the aging process.