Flare Response Research Articles

Clinical significance of early kinetics of C‑reactive protein in patients with advanced urothelial carcinoma treated with pembrolizumab: Flare response and baseline levels predict oncological outcomes.

Data on the C-reactive protein (CRP) flare response in patients with metastatic and unresectable urothelial carcinoma (mUC) are limited. The present study aimed to clarify the clinical significance of the CRP flare response in patients with mUC who received pembrolizumab. Between March 2018 and December 2022, patients with mUC who received pembrolizumab following chemotherapy were retrospectively reviewed. Patients were categorized into three groups based on the early kinetics of CRP: i) Flare-responders, in which CRP levels increased >2-fold from baseline (BL) within 1 month after pembrolizumab administration (CRP flare) and decreased to below-BL levels within 3 months; ii) responders, in which CRP levels decreased ≥30% from baseline within 3 months without CRP flare; and iii) non-responders, which included the remaining patients. Tumor response, survival and incidence of immune-related adverse events (AEs) were compared between the groups. Of the 108 eligible patients, 17 (16%), 27 (25%) and 64 (59%) were classified as CRP flare-responders, CRP responders and CRP non-responders, respectively. Objective response rate was higher in CRP flare-responders and CRP responders than in CRP non-responders. Progression-free survival and overall survival were longer in CRP flare-responders and CRP responders than in CRP non-responders. Among CRP flare-responders, patients with low BL CRP levels had a better tumor response and survival than patients with high BL CRP levels. Notably, there was no difference in the incidence of immune-related AEs. In patients with mUC who received pembrolizumab, CRP flare-responders showed favorable oncological outcomes; therefore, BL CRP levels could predict oncological outcomes in CRP flare-responders.

Comparative inhibition by oral bilastine, parenteral dexchlorpheniramine, and a new bilastine parenteral (i.v. and i.m.) formulation of histamine-induced wheal and flare response: A randomised phase I trial

BackgroundBilastine is a well-known non-sedating second-generation antihistamine authorised worldwide for the symptomatic treatment of allergic rhinoconjunctivitis (seasonal and perennial) and urticaria with proven efficacy and good safety and tolerability profile. When the oral route is not suitable or a rapid onset of action is preferred, parenteral formulations represent an effective treatment option. However, the parenteral formulations currently available are sedating antihistamines. The objective of this research was to compare the peripheral anti-H1 activity of different bilastine formulations (i.v., i.m. and oral) and dexchlorpheniramine among them also versus placebo. MethodsThis was a single-dose, randomized, crossover, double-blind, placebo-controlled, phase I clinical study performed on 25 adult healthy volunteers that compared the peripheral antihistaminic activity of a single dose of bilastine 12 mg i.v., bilastine 12 mg i.m., bilastine 20 mg oral tablets and dexchlorpheniramine 5 mg i.m. among them and versus placebo by inhibiting the histamine-induced wheal and flare (W&F) response. Pharmacokinetics, safety, and tolerability were also evaluated. ResultsAll bilastine formulations showed a rapid onset of action (15 min for parenteral and 30 min for the oral formulation), and the maximum effect in both wheal (i.v. 74.44 %; i.m.:74.29 %; oral 70,27 %) and flare area reduction (i.v. and i.m. 80.63 %; oral 77.67 %), was significantly larger compared to dexchlorpheniramine i.m. (25.85 % for wheal and 28.65 % for flare) and placebo (1.35 % for wheal and 4.02 % for flare). A more pronounced reduction in itching score was reached for bilastine oral, followed by i.m. and i.v. formulations. No serious adverse events (SAEs) were reported during the study, and 8 treatment-emergent adverse events (TEAEs) were reported by 5 subjects, all resolved without sequelae. For psychomotor assessments, dexchlorpheniramine i.m. showed a fast onset of drowsiness, as well as decreased attention and coordination when compared to all bilastine formulations and placebo. ConclusionsAll bilastine formulations showed a peripheral H1-blocking effect inducing a significantly greater inhibition of the wheal and flare response as compared to dexchlorpheniramine i.m. or placebo and provided a greater reduction of the itching sensation score. This study reconfirmed that bilastine has no sedative effect, even in a parenteral formulation. These results suggest that new bilastine parenteral formulation (i.v. or i.m.) may represent a suitable alternative for patients requiring immediate treatment of histamine-mediated type I hypersensitivity reactions, such as acute urticaria, or in those cases where oral administration is not possible.

Depolarization of mouse DRG neurons by GABA does not translate into acute pain or hyperalgesia in healthy human volunteers.

The majority of somatosensory DRG neurons express GABAA receptors (GABAAR) and depolarise in response to its activation based on the high intracellular chloride concentration maintained by the Na-K-Cl cotransporter type 1 (NKCC1). The translation of this response to peripheral nerve terminals in people is so far unclear. We show here that GABA (EC50 = 16.67μM) acting via GABAAR produces an influx of extracellular calcium in approximately 20% (336/1720) of isolated mouse DRG neurons. In contrast, upon injection into forearm skin of healthy volunteers GABA (1mM, 100μl) did not induce any overt sensations nor a specific flare response and did not sensitize C-nociceptors to slow depolarizing electrical sinusoidal stimuli. Block of the inward chloride transporter NKCC1 by furosemide (1mg/100μl) did not reduce electrically evoked pain ratings nor did repetitive GABA stimulation in combination with an inhibited NKCC1 driven chloride replenishment by furosemide. Finally, we generated a sustained period of C-fiber firing by iontophoretically delivering codeine or histamine to induce tonic itch. Neither the intensity nor the duration of histamine or codeine itch was affected by prior injection of furosemide. We conclude that although GABA can evoke calcium transients in a proportion of isolated mouse DRG neurons, it does not induce or modify pain or itch ratings in healthy human skin even when chloride gradients are altered by inhibition of the sodium coupled NKCC1 transporter.

C-reactive protein flare predicts response to checkpoint inhibitor treatment in melanoma.

The treatment of melanoma has been revolutionized by the use of immune checkpoint inhibition (ICI), but many patients do not benefit. Furthermore, immune-related adverse events may occur during therapy. A predictive biomarker is needed to reliably identify patients benefitting. In lung, renal cell and bladder cancer early C-reactive protein (CRP) kinetics were shown to be a predictive biomarker for ICI. Here, we investigate early CRP kinetics as predictive biomarker for ICI in melanoma patients. Two independent prospectively collected cohorts were analysed: Cohort 1 (n = 87) with advanced and Cohort 2 (n = 99) with completely resected melanoma. Patients were stratified by in the dynamics of CRP after ICI initiation: A doubling of baseline CRP within 30 days followed by at least a 30% drop within 3 months was classified as a CRP flare. If no doubling of CRP was reported, but a 30% drop within 3 months, patients were classified as CRP responders and all others as CRP non-responders. Analysed factors included clinical characteristics like S100B and LDH. Median follow-up was 1.5 and 1.7 years for Cohorts 1 and 2. In Cohort 1 CRP flare (n = 12), CRP responders (n = 43) and CRP non-responders (n = 32) with a progression-free survival (PFS) of 0.7, 0.6 and 0.2 years (p = 0.017) and an overall survival (OS) of 2.2, 1.5 and 1.0 years (p = 0.014), respectively. Multivariable Cox analysis showed an independent risk reduction of progression for CRP responders by 62% compared to CRP non-responders (p = 0.001). In Cohort 2 CRP flare (n = 13), CRP responders (n = 70) and CRP non-responders (n = 16) the log-rank analysis showed a significant difference between OS and recurrence-free survival (RFS) curves (p = 0.046 and p = 0.049). Early CRP kinetics could indicate a response to ICI with improved OS and RFS/PFS. CRP flare and CRP response indicating significantly improved outcomes compared to CRP non-responders.

Hemispheric comparison of solar flare associated cosmic noise absorption (SCNA) from high latitude stations: Maitri (70.75°S, 11.75°E) and Abisko (68.4°N, 18.9°E)

The effects of solar flares in the D-region ionosphere at two high-latitude stations: Maitri (70.75°S, 11.75°E) and Abisko (68.4°N, 18.9°E), located in different hemispheres are studied. We analyzed 37 M-class flares and 6 X-class flares of the year 2014, which occurred when either or both stations were in the sun-lit side of the Earth. Cosmic Noise Absorption (CNA) curves are obtained using the datasets of riometers located at the two stations and are analyzed for all the 43 events under study. This paper discusses: 1) relationship between CNA and flare magnitude, 2) relationship between CNA and solar zenith angle (SZA), 3) hemispheric asymmetry in the observed solar flare associate CNA (or SCNA), and 4) the effect of background ionospheric condition in the SCNA magnitude at the two high latitude stations. It is observed that the solar flare effect in SCNA strongly depends on the SZA and flare intensity. Our analysis reveals that the flare response in SCNA for the year 2014 was stronger at Abisko than at Maitri. There is an observed hemispheric asymmetry in the solar flare ionization at D-region ionosphere for the given latitude. This asymmetry can be attributed to the previously enhanced background ionospheric ionization during particle precipitation processes. This study shows the need to establish an empirical relationship between the observed CNA vs. flare intensity, SZA and latitudinal position; especially when we go higher in latitudes.

Clinical impact of C-reactive protein flare response in patients with advanced urothelial carcinoma who received pembrolizumab.

Clinical impact of C-reactive protein flare response in patients with advanced urothelial carcinoma who received pembrolizumab.

A comparative study of two X2.2 and X9.3 solar flares observed with HARPS-N

Context. Stellar flares cannot be spatially resolved, which complicates ascertaining the physical processes behind particular spectral signatures. Due to their proximity to Earth, solar flares can serve as a stepping stone for understanding their stellar counterparts, especially when using a Sun-as-a-star instrument and in combination with spatially resolved observations. Aims. We aim to understand the disk-integrated spectral behaviors of a confined X2.2 flare and its eruptive X9.3 successor, which had energies of 2.2 × 1031 erg and 9.3 × 1031 erg, respectively, as measured by Sun-as-a-star observations with the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N). Methods. The behavior of multiple photospheric (Na D1 & D2, Mg I at 5173 Å, Fe I at 6173 Å, and Mn I at 4031 Å) and chromospheric (Ca II H & K, Hα, Hβ, and He ID3) spectral lines were investigated by means of activity indices and contrast profiles. A number of different photospheric lines were also investigated by means of equivalent widths, and radial velocity measures, which were then related to physical processes directly observed in high-resolution observations made with the Swedish 1-m Solar Telescope (SST) and the Atmospheric Imaging Assembly (AIA) on board of the Solar Dynamics Observatory (SDO). Results. Our findings suggest a relationship between the evolving shapes of contrast profile time and the flare locations, which assists in constraining flare locations in disk-integrated observations. In addition, an upward bias was found in flare statistics based on activity indices derived from the Ca II H & K lines. In this case, much smaller flares cause a similar increase in the activity index as that produced by larger flares. Hα-based activity indices do not show this bias and are therefore less susceptible to activity jitter. Sodium line profiles show a strongly asymmetric response during flare activity, which is best captured with a newly defined asymmetrical sodium activity index. A strong flare response was detected in Mn I line profiles, which is unexpected and calls for further exploration. Intensity increases in Hα, Hβ, and certain spectral windows of AIA before the flare onset suggest their potential use as short-term flare predictors.

Screening of Strawberry Allergy in Egyptian Atopic Children

Background Strawberries are included in the list of allergenic foods. However, definite figures in many countries including Egypt are lacking. Children with food allergy are 2 to 4 times more likely to have asthma, eczema, and allergic rhinitis than their non-allergic peers. We therefore sought to investigate IgE-mediated strawberry sensitization among a group of atopic children and correlate it to their clinical and laboratory parameters. Patients and Methods This study comprised 256 children, 1 to 18 years old, with physician-diagnosed bronchial asthma (98 patients), allergic rhinitis (28 patients), atopic dermatitis (53 patients), food allergy (10 patients) and combined allergies (67 patients). They were enrolled consecutively from the Pediatric Allergy, Immunology and Rheumatology Unit, Children's Hospital, Ain Shams University, Cairo. Sensitization to strawberry was assessed using prick-prick test (PPT). Results Strawberry sensitization was observed in 7.8% of the studied children. Confirmed strawberry allergy was elicited in 2% of them. Strawberry sensitization was more prevalent in patients with food allergy followed by those with atopic dermatitis. Severity of allergic disease, frequency of flare ups and response to treatment did not influence the rate of strawberry sensitization in our series. Conclusion Strawberry allergy is not as common as claimed to be among Egyptian children with allergic disorders. Sensitization to strawberry did not impact the severity of allergy or response to treatment. The findings are limited by the sample size.

Intradermal substance P as a challenge agent in healthy individuals.

Pharmacological challenge models are deployed to evaluate drug effects during clinical development. Intradermal injection of Substance P (SP) neuropeptide, a potential challenge agent for investigating local mediators, is associated with wheal and flare response mediated by the MRGPRX2 receptor. Although dose-dependent data on SP effects exist, full characterization and information on potential carryover effect after repeated challenge are lacking. This open-label, two-part, prospective enabling study of SP intradermal challenge in healthy participants aimed to understand and distinguish between wheal and flare responses following various SP doses. Part 1 included one challenge visit to determine optimum SP dose range for evaluation in part 2, which determined variability in 20 participants and used intradermal microdialysis (IDM) for SP-challenged skin sampling. At 5, 15, 50, and 150 pmol doses, respectively, posterior median area under the curve (AUC; AUC0-2h ) was 4090.4, 5881.2, 8846.8, and 9212.8 mm2 /min, for wheal response, and 12020.9, 38154.3, 65470.6, and 67404.4 mm2 /min for flare response (SP-challenge visit 2). When the challenge was repeated ~2 weeks later, no carryover effect was observed. IDM histamine levels were relatively low, resulting in low confidence in the data to define temporal characteristics for histamine release following SP challenge. No safety concerns were identified using SP. Wheal and flare responses following intradermal SP challenge were dose-dependent and different. The results indicate that this challenge model is fit-for-purpose in future first-in-human studies and further assessment of novel drugs targeting dermal inflammatory disease responses, such as chronic spontaneous urticaria, chronic inducible urticaria, and pseudo-allergic reactions.

Optimizing examination time and diagnostic performance of the histamine-induced axon-reflex flare response in diabetes.

The axon-reflex flare response is a reliable method for functional assessment of small fibers in diabetic peripheral neuropathy (DPN), but broad adoption is limited by the time requirement. The aims of this study were to (1) assess diagnostic performance and optimize time required for assessing the histamine-induced flare response and (2) associate with established parameters. A total of 60 participants with type 1 diabetes with (n = 33) or without (n = 27) DPN participated. The participants underwent quantitative sensory testing (QST), corneal confocal microscopy (CCM), and flare intensity and area size assessments by laser-Doppler imaging (FLPI) following an epidermal skin-prick application of histamine. The flare parameters were evaluated each minute for 15 min, and the diagnostic performance compared to QST and CCM were assessed using area under the curve (AUC). Minimum time-requirements until differentiation and to achieve results comparable with a full examination were assessed. Flare area size had better diagnostic performance compared with CCM (AUC 0.88 vs. 0.77, p < 0.01) and QST (AUC 0.91 vs. 0.81, p = 0.02) than mean flare intensity, and could distinguish people with and without DPN after 4 min compared to after 6 min (both p < 0.01). Flare area size achieved a diagnostic performance comparable to a full examination after 6 and 7 min (CCM and QST respectively, p > 0.05), while mean flare intensity achieved it after 5 and 8 min (CCM and QST respectively, p > 0.05). The flare area size can be evaluated 6-7 min after histamine-application, which increases diagnostic performance compared to mean flare intensity.

Intravitreal versus Oral Steroids for Inflammation Control in Uveitic Patients Undergoing Cataract Surgery

ABSTRACT Background This prospective experimental study was conducted on 40 eyes of 40 patients with complicated uveitic cataracts to compare a single intraoperative intravitreal injection of triamcinolone acetonide (IVTA) with oral steroids for inflammation control after cataract extraction. Methods The IVTA group (19 eyes) received an intravitreal injection of 4 mg/0.1 ml triamcinolone acetonide intraoperatively, and the oral steroid group (19 eyes) received oral steroids peri-operatively. Two patients had to be excluded from the study because they underwent extracapsular cataract extraction (ECCE), instead of phacoemulsification. Results A statistically significant difference was observed in the anterior chamber cell and flare response between both groups initially, but by the last follow-up, this became insignificant. None of the patients in each group experienced a recurrence of uveitis nor developed cystoid macular edema. Five patients in the oral steroid group had IOP >21 mmHg post-operatively. Conclusion A single injection of 4 mg IVTA has similar efficacy to peri-operative oral steroid administration.

Characterization of trigeminal C-fiber reactivity through capsaicin-induced release of calcitonin gene-related peptide.

We hypothesized that the response of trigeminal dermal blood flow (DBF) in the trigeminal system and consecutive expansion of flare response to capsaicin would differ from the somatosensory system (arm). We also investigated whether there are differences between patients with migraine and healthy controls (HC). Functional differences between the trigeminal and extracephalic somatosensory systems may partly explain the susceptibility for headaches in patients with migraine. Capsaicin-induced activation of nociceptive C-fibers in the skin is mainly mediated by calcitonin gene-related peptide (CGRP) and induces cutaneous vessel dilatation and flare response. Female patients with migraine (n=38) and age-matched HC (n=35) underwent DBF measurement at baseline and after topical capsaicin administration using laser speckle imaging. DBF before and after capsaicin stimulation was analyzed over ophthalmic nerve/maxillary nerve/mandibular nerve (V1/V2/V3) dermatomes and the forearm as an extracephalic control. Capsaicin-induced DBF increased more in the trigeminal dermatomes than on the forearm. The V1 dermatome showed a smaller increase of DBF in patients with migraine compared to HC. Our results suggest that the trigeminovascular system reacts differently from extracephalic areas, which may explain the trigeminal susceptibility to CGRP-mediated pain attacks. By demonstrating a different reactivity of the V1 dermatome in patients with migraine, our finding suggests that the first trigeminal branch is functionally different from the second and third branches; however, only in patients with migraine.

Scoring personalized molecular portraits identify Systemic Lupus Erythematosus subtypes and predict individualized drug responses, symptomatology and disease progression.

ObjectivesSystemic Lupus Erythematosus is a complex autoimmune disease that leads to significant worsening of quality of life and mortality. Flares appear unpredictably during the disease course and therapies used are often only partially effective. These challenges are mainly due to the molecular heterogeneity of the disease, and in this context, personalized medicine-based approaches offer major promise. With this work we intended to advance in that direction by developing MyPROSLE, an omic-based analytical workflow for measuring the molecular portrait of individual patients to support clinicians in their therapeutic decisions.MethodsImmunological gene-modules were used to represent the transcriptome of the patients. A dysregulation score for each gene-module was calculated at the patient level based on averaged z-scores. Almost 6100 Lupus and 750 healthy samples were used to analyze the association among dysregulation scores, clinical manifestations, prognosis, flare and remission events and response to Tabalumab. Machine learning-based classification models were built to predict around 100 different clinical parameters based on personalized dysregulation scores.ResultsMyPROSLE allows to molecularly summarize patients in 206 gene-modules, clustered into nine main lupus signatures. The combination of these modules revealed highly differentiated pathological mechanisms. We found that the dysregulation of certain gene-modules is strongly associated with specific clinical manifestations, the occurrence of relapses or the presence of long-term remission and drug response. Therefore, MyPROSLE may be used to accurately predict these clinical outcomes.ConclusionsMyPROSLE (https://myprosle.genyo.es) allows molecular characterization of individual Lupus patients and it extracts key molecular information to support more precise therapeutic decisions.

18F]Fluorothymidine(FLT)-PET imaging of thymidine kinase 1 pharmacodynamics in non-small cell lung cancer treated with pemetrexed.

3070 Background: Imaging of tumor proliferation has been studied with FLT-PET in various tumor types including NSCLC. Pemetrexed inhibits thymidylate synthase(TS), dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). TS inhibition upregulates the thymidine salvage pathway including relocalisation of ENT1 to membrane and TK1 activation as a transient “flare” response. We hypothesise that this can be detected as an increase in FLT tumoral uptake that subsequently decreases with reduced proliferation. This study was conducted to assess FLT uptake as an early pharmacodynamics(PD) marker of pemetrexed response. Methods: This was an open-label imaging study in 21 patients with Stage 3/4 NSCLC treated with pemetrexed and platinum-based chemotherapy. Patients underwent FLT PET/CT scan at baseline and 4h after administration of pemetrexed. Platinum component of treatment was administered on the day after second FLT scan for cycle 1. Plasma for TK1 activity expression were collected before each scan time point and analysed by ELISA. Percentage change in standardized uptake value (%ΔSUV) was calculated as [SUV(PET2) – SUV(PET1)]/ SUV(PET1)*100. Treatment response calculated by RECIST 1. 1 and survival data were collected. Results: 17 patients had evaluable PET/CT scans for pemetrexed response. Median percentage difference for SUVmean and SUVmax in tumour lesions increased by 3% and 10.3% respectively. 5 patients showed homogeneous FLT flare at 4h after pemetrexed, 2 patients had decrease, 10 patients had heterogeneous FLT response (regardless of platinum doublet). There was no significant correlation between plasma TK1 activity and FLT flare. At 9 weeks, 4 patients had partial response, 9 stable disease and 4 progressive disease. Baseline and weighted average ΔSUVmax were not associated with survival. The 5 patients with FLT flare in all lesions showed a median OS of 31 months, unlike the group with heterogenous or decrease uptake(15 months). FLT uptake in bone marrow and small bowel significantly increased at 4h (t test p = 0.004, p = 0.004, respectively) indicating increased thymidine salvage activity. Early FLT uptake was not predictive for tumour RECIST response or OS. In multivariable cox regression analysis, pre-treatment TK1 activity, adjusted for performance status, smoking history and age, independently affected survival in this group (p = 0.011). Conclusions: Early FLT flare at 4h was seen in NSCLC post pemetrexed administration indicating activation of thymidine salvage pathway. Median overall survival of patients with an FLT flare response was more than twice longer than patients with mixed or no response. However, the small sample size lacked power to show statistical significance in the OS comparison. Further studies should evaluate this and the relationship to other prognostic variables in a larger cohort of patients. Clinical trial information: NCRI UK badge 9249.

Tests of a New Solar Flare Model Against D and E Region Ionosphere Data

AbstractWe present results from a suite of models designed to simulate solar flare effects on the D and E region of the ionosphere. This suite includes models of the solar spectrum, the ionosphere and of HF radiowave propagation. A central component of this system is the development of photoelectron ionization enhancement factors with higher energy resolution in the soft X‐ray spectral region that can be used to supplement existing ionization schemes currently implemented in upper atmospheric general circulation models. We tested this photoelectron model in the NCAR Thermosphere‐Ionosphere‐Mesosphere‐ Electrodynamics General Circulation Model (TIME‐GCM) and in a photochemical model of the D region. In both cases, we compared predicted flare response using two different input solar flare spectra. One is the Flare Irradiance Spectral Model (FISM) and the other is a physics based model called NRLFLARE. Our predictions for the E region were compared with incoherent scatter radar data and suggest that enhanced flux in the 1–2 nm spectral region, as indicated by NRLFLARE, is important for reproducing the observations. For the D region, we combined our theoretical results for the X1.3 flare of 7 September 2017 with ray tracing calculations that suggest 20–40 db of 6.4 MHz absorption. This agrees with previously published observations and model estimates, all of which suggest greater HF absorption than the operational D region absorption prediction model (swpc.noaa.gov/products/d‐region‐absorption‐predictions‐d‐rap). Finally, our theoretical comparison with previously published empirical models derived from very low frequency data was less clear due, in part, to large differences between the different empirical models.

C-reactive protein flare predicts response to anti-PD-(L)1 immune checkpoint blockade in metastatic urothelial carcinoma

PurposeRobust biomarkers to predict response to immune checkpoint blockade (ICB) in metastatic urothelial carcinoma (mUC) are still in demand. Recently, early C-reactive protein (CRP) kinetics and especially the novel CRP flare-response phenomenon has been associated with immunotherapy response. MethodsWe conducted a multicentre observational study comprising 154 patients with mUC treated with ICB to evaluate the predictive value of a previously described on-treatment CRP kinetics: CRP flare responders (at least doubling of baseline CRP within the first month after initiation of ICB followed by a decline below baseline within three months), CRP responders (decline in baseline CRP by ≥ 30% within three months without a prior flare) and the remaining patients as CRP non-responders. CRP kinetics groups were correlated with baseline parameters, PD-L1 status, progression-free survival (PFS) and overall survival (OS). ResultsObjective response was observed in 57.1% of CRP responders, 45.8% of CRP flare responders and 17.9% of CRP non-responders (P < 0.001). CRP flare response was associated with prolonged PFS and OS (P < 0.001). In multivariable Cox regression analysis, CRP flare responders showed a risk reduction of ∼70% for tumour progression and death compared to CRP non-responders. Subgroup analysis of CRP flare responders revealed that patients with a long-flare response (completed flare-response kinetics ≥6 weeks on-treatment) showed even more favourable outcomes following ICB (HR = 0.18, 95%-CI: 0.07–0.48, P < 0.001). ConclusionCRP (flare)response robustly predicts immunotherapy response and outcomes in mUC independent of PD-L1 status. Thus, early on-treatment CRP kinetics is a promising low-cost and easy-to-implement biomarker to optimise therapy monitoring in patients with mUC treated with ICB.

The Histamine-Induced Axon-Reflex Response in People With Type 1 Diabetes With and Without Peripheral Neuropathy and Pain: A Clinical, Observational Study

Small nerve fibres are important when studying diabetic peripheral neuropathy (DPN) as they could be first affected. However, assessing their integrity and function adequately remains a major challenge. The aim of this study was to investigate the association between different degrees of DPN, the presence of neuropathic pain, and the intensity of the axon-reflex flare response provoked by epidermal histamine. Eighty adults were included and divided into 4 groups of 20 with type 1 diabetes and: painful DPN (T1DM+PDPN), non-painful DPN (T1DM+DPN), no DPN and no pain (T1DM-DPN), and 20 persons without diabetes or pain (HC). The vasomotor responses were captured by a Full-field Laser Speckle Perfusion Imager. The response was lowest in T1DM+DPN, followed by T1DM+PDPN, T1DM-DPN and HC. The response was significantly reduced in DPN (T1DM+DPN, T1DM+PDPN) compared with people without (T1DM-DPN, HC) (P < .001). The response was also attenuated in diabetes irrespective of the degree of DPN (T1DM+PDPN, T1DM+DPN, T1DM-DPN) (P < .001). There were no differences in the response between painful neuropathy (T1DM+PDPN) and painless DPN (T1DM+DPN) (P = .189). The method can distinguish between groups with and without diabetes and with and without DPN but cannot distinguish between groups with and without painful DPN. PerspectiveThis study describes how diabetes attenuates the axon-reflex response, and how it is affected by neuropathy and pain clarifying previous findings. Furthermore, the study is the first to utilize histamine when evoking the response, thus providing a new and fast alternative for future studies into the pathophysiology of neuropathic pain.

Microinjection of pruritogens in NGF-sensitized human skin

Single intradermal injections of nerve growth factor (NGF) evoke prolonged but temporally distinct sensitization patterns to somatosensory stimuli. Focal administration of the non-histaminergic pruritogen cowhage but not histamine resulted in elevated itch at day 21 after NGF administration. Here, we injected bovine adrenal medulla peptide 8–22 (BAM8–22), β-alanine (β-ALA) and endothelin-1 (ET-1) into NGF-treated skin of 11 healthy volunteers and investigated the corresponding itch/pain and flare reactions. β-ALA was the weakest pruritogen, while BAM8–22 and ET-1 were equally potent as histamine. NGF did not sensitize itch or flare reactions induced by any compound, but injection and evoked pain were increased at day 21 and 49. The involvement of histamine H1 receptors in itch was explored in eight subjects after oral cetirizine. ET-1-induced itch and flare were significantly reduced. BAM8–22 and β-ALA itch were not affected, but flare responses after BAM8–22 reduced by 50%. The results indicate that a single NGF injection does not sensitize for experimentally induced itch but increases pain upon pruritogen injection. In healthy humans, pruritic and algetic processing appear differentially regulated by NGF. However, in patients suffering chronic itch, prolonged elevation of NGF-levels under inflammatory conditions may contribute to elevated itch.

26420 Vulvar pain and pruritus secondary to dermatographism: An underrecognized etiology

Vulvar manifestations of dermatographism, which include itching, swelling, burning, and irritation, are not well-documented. Dermatographism is entirely excluded from current vulvar disease guidelines. We present a 23-patient series identified via retrospective chart review, alongside an illustrative case. From 2008-2020, 23 women presenting to a single provider for vulvovaginal complaints were dermatographic on physical examination. Presenting age averaged 42.76 years (range 17-75), with symptom duration of 32.53 months (range 10-72). Among eleven returning patients (M = 11.85 months follow-up; range 0.5-38), 91% (n = 10) reported symptomatic improvement with hydroxyzine treatment. A 35-year-old female presented with 10-month history of severe vulvar pruritus unresponsive to repeated antibiotic and topical steroid therapy. Symptoms impaired her concentration, daily activities, and sleep. Prior biopsies demonstrated mild dermal telangiectasias and attenuation of collagen possibly representing steroid atrophy but no evidence of active inflammatory process or atypia; periodic acid–Schiff stain was negative. Physical examination revealed no vulvar atrophy, erythema, or other dermatologic changes. Notably, the patient demonstrated marked dermatographism with wheal and flare response on her back. She reported improvement of vulvar symptoms within 1 week of initiating hydroxyzine treatment. Three years later, the patient maintains excellent control with hydroxyzine 10 mg nightly. Dermatologists and gynecologists alike should include dermatographism in the differential for vulvar complaints. The simple screening test (tic-tac-toe board drawn on the back) and high responsiveness to antihistamine treatment can prove gratifying to both patients and clinicians. Given the complexity of vulvar pain and itch, an etiology so easily screened and treated warrants consideration.

Neurogenic Flare Response following Image-Guided Focused Ultrasound in the Mouse Peripheral Nervous System in Vivo

Focused ultrasound (FUS) has been used to non-invasively elicit or inhibit motor neuronal activity in the mouse peripheral nervous system in vivo. However, less is known about whether FUS elicits immune system responses associated with peripheral sensory neuronal activity. In this study, we sought to determine that non-invasive ultrasound image-guided FUS can elicit the neurogenic axon reflex of peripheral nerves in the mouse sciatic nerve. The local vasodilation in the plantar view of the hind paw detected with a high-resolution laser Doppler imager indicated neurogenic flare responses after FUS stimulation. The effects of FUS were compared with control groups, where a distinct pattern of blood flow changes was observed only in FUS-elicited neurogenic flare responses. The findings indicate that image-guided FUS elicits local axon reflexes in vivo with a high degree of specificity and penetration depth.