PO-86 | CGRP, VIP and PACAP plasmatic levels in migraine patients before and after anti-CGRP(R) monoclonal antibodies prophylaxis

BackgroundAn increasing number of studies have suggested that the important role of vasoactive peptides, such as pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38) and calcitonin gene-related peptide (CGRP), in the pathophysiology of migraine seems undeniable in adults, but studies in pediatric migraine patients remain scarce. We prospectively investigated CGRP and PACAP-38 plasma levels in children with migraine during ictal and interictal periods and compared the results between migraine patients with aura and without aura. We were the first to explore the diagnostic value of a combination of CGRP and PACAP-38.MethodsSeventy-six migraine patients aged 4–18 years and seventy-seven age-matched healthy children were included in the study. Plasma vasoactive peptides were measured using the enzyme-linked immunosorbent assay (ELISA). Differences and correlations of groups were analyzed using the independent samples t-test, analysis of variance (ANOVA), Mann-Whitney U test, and multiple linear regression. We also performed logistic regression and receiver operating characteristic curve (ROC) analyses to evaluate the diagnostic value of CGRP and PACAP-38 in pediatric migraine.ResultsPACAP-38 and CGRP levels in migraine patients during the ictal and interictal periods were higher than those in controls (p < 0.001). PACAP-38 and CGRP levels in migraine patients with aura and without aura were higher than those in controls (p < 0.001). PACAP-38 and CGRP were independent risk factors in diagnosing pediatric migraine (adjusted OR (PACAP-38) =1.331, 95% CI: 1.177–1.506, p < 0.001; adjusted OR (CGRP) = 1.113, 95% CI: 1.064–1.165, p < 0.001). Area Under Curve (AUC) comparison: Combination (0.926) > CGRP (0.869) > PACAP-38 (0.867).ConclusionsOur study found almost the same changes in CGRP and PACAP levels in pediatric migraine, suggesting that CGRP and PACAP-38 may work together to play an integral role in pediatric migraine. Higher CGRP levels were found in the ictal phase than in the interictal phase and with aura group than without aura group, indicating that CGRP may take part in the formation of pain and aura. Moreover, ROC and logistic regression analyses suggested that CGRP and PACAP-38 are good indicators to diagnose pediatric migraine, and the combination of CGRP and PACAP-38 was valuable in diagnosing pediatric migraine and differentiating pediatric migraine from non-migraine headaches.Trial registrationThe study has been registered at the Chinese Clinical Trial Registry (ChiCTR2100043157).

Background: Monoclonal antibodies (mAbs) targeting the calcitonin gene-related peptide (CGRP) pathway have revolutionized migraine prophylaxis. However, a subset of patients does not respond to these therapies, highlighting an urgent need for predictive biomarkers. This study investigates whether baseline plasma levels of CGRP or pituitary adenylate cyclase activating peptide (PACAP)-38 may predict the clinical response to anti-CGRP mAbs in patients with high-frequency episodic migraine (HFEM) or chronic migraine (CM). Methods: A prospective, longitudinal study was conducted on migraine patients treated with erenumab, fremanezumab, or galcanezumab. Clinical outcomes, including monthly migraine days (MMD), Migraine Disability Assessment (MIDAS), and monthly medication intake (MMI), were assessed at baseline (T0), 3 months (T1), and 6 months (T2). A group of healthy subjects was used as controls. Plasma CGRP and PACAP-38 levels were measured using an enzyme-linked immunosorbent assay (ELISA). Treatment responses were tested using bivariate and multivariate analyses. Results: 30 females, 7 males (17 HFEM, 20 CM), and 16 healthy controls were included in the study. Baseline plasma CGRP and PACAP-38 concentrations were higher in migraine patients than in controls (p&lt;0.01 and p&lt;0.001, respectively). Baseline CGRP levels significantly correlated with worse clinical outcomes at 6 months: higher CGRP was associated with greater MMD (r=0.470, p=0.003), MIDAS scores (r=0.601, p&lt;0.001), and MMI (r=0.410, p=0.010) at T2. Additionally, higher baseline CGRP levels were associated with a lower likelihood of achieving a ≥50% reduction in MIDAS scores. Multivariate regression confirmed that elevated CGRP independently predicted poorer response, particularly in CM patients. Conversely, PACAP-38 levels did not emerge as significant predictors of any clinical outcome measures. Conclusions: Our study shows that higher baseline plasma CGRP levels predict a reduced clinical response to anti-CGRP mAbs in patients with HFEM and CM after 6 months, supporting CGRP as a potential biomarker for treatment stratification. PACAP-38 levels did not influence treatment outcomes, indicating a distinct role in migraine pathophysiology. These results encourage further research into personalized treatment approaches based on neuropeptide profiling.

Migraine pathophysiology involves the release of vasoactive neuropeptides following trigeminovascular system activation. While calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38) have been individually studied in migraine, their combined role in differentiating migraine subtypes remains unclear. The aim of this study was to evaluate serum levels of CGRP, VIP and PACAP-38 in patients with migraine with aura (MA) and without aura (MO) compared to healthy controls (HC), and assess their potential as diagnostic biomarkers. This case-control study included 296 participants (266 females, 30 males) divided into three groups: MA (n = 101), MO (n = 98) and HC (n = 97). Serum neuropeptide levels were measured using enzyme-linked immunosorbent assay (ELISA) under standardised conditions. Clinical characteristics were assessed using attack frequency and Headache Impact Test-6 (HIT-6) scores. All three neuropeptides were significantly elevated in migraine patients compared to controls (p < .001). CGRP levels were highest in MA (45.6 ± 8.2 pg/mL), followed by MO (38.4 ± 7.8 pg/mL) and HC (28.3 ± 6.4 pg/mL). Similar patterns were observed for VIP (MA: 186.4 ± 24.6, MO: 165.8 ± 22.4, HC: 142.3 ± 20.8 pg/mL) and PACAP-38 (MA: 248.6 ± 32.4, MO: 228.5 ± 30.6, HC: 195.4 ± 28.2 pg/mL). MA patients showed marginally higher attack frequency (4.8 ± 2.3 vs. 4.2 ± 2.1 per month, p = .06) and HIT-6 scores (64.8 ± 6.2 vs 62.4 ± 5.8, p = .08) compared to MO patients. The significant elevation of all three neuropeptides, particularly in MA patients, suggests their potential utility as biomarkers for migraine diagnosis and subtype differentiation. These findings support the neurogenic inflammation hypothesis in migraine pathophysiology and may have implications for targeted therapeutic approaches.

Onabotulinumtoxin type A (onabotA) has shown efficacy in chronic migraine (CM). Its precise mechanism of action, however, is unknown. To analyze a potential relationship between calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP) levels and response to onabotA in CM. Adult patients with CM were recruited. Matched healthy subjects with no headache history served as controls. CGRP and VIP levels were determined in samples obtained from the right antecubital vein by ELISA outside of a migraine attack and having taken no symptomatic medication prior to treatment with onabotA. OnabotA was administered according to the PREEMPT protocol every 12 weeks for at least two treatment cycles. A patient was considered as a moderate responder when both: (1) moderate-severe headache episodes were reduced by between 33 and 66%; (2) subjective benefit in a visual scale of 0-100 was recorded by the patient of between 33-66%. Patients were considered as excellent responders when both items improved >66%. Those without improvement of at least one-third in the two items were considered as nonresponders. We assessed plasma samples from 81 patients with CM and 33 healthy controls. CGRP and VIP levels were significantly increased in CM population vs controls. CGRP and, to a lesser degree, VIP levels were significantly increased in responders vs nonresponders. For CGRP, a threshold of 72 pg/mL positively correlated with 95% of nonresponders. The probability of being a responder to onabotA was 28 times higher in patients with a CGRP level above the threshold of 72 pg/mL. Even though the sensitivity for the calculated threshold for VIP was poor, the probability that CM patients with low CGRP levels will respond to onabotA was significantly higher in those patients with high VIP levels. Interictal CGRP and, to a lesser degree, VIP levels measured in peripheral blood are of great help in predicting response to onabotA.

Granulocyte colony-stimulating factor provides protection against cardiovascular autonomic neuropathy in streptozotocin-induced diabetes in rats

Migraine is one of the most disabling diseases that continues to pose a significant societal burden. Although there are now treatment options for people with migraine, it remains challenging to identify them as clinical features are diverse and complex, and there are no validated diagnostic or treatment prediction biomarkers. Identification is based on either diagnostic coding or the use of certain acute headache abortive treatments. However, socioeconomic disparities can contribute to under-diagnosis and under-treatment of migraine. Thus, efforts to find biomarkers to identify individuals with migraine and which variables could explain migraine-related chronification and disability are warranted. We aimed to investigate the levels of migraine inducing neuropeptides; calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating polypeptide (PACAP) in peripheral blood samples as potential biomarkers of migraine. We developed highly sensitive assays for CGRP and PACAP on the MSD S-PLEX assay platform and used them for bioanalysis of preclinical and clinical samples. Wildtype and neuropeptide challenged mice and rats were profiled using the developed assay. To follow-up, commercially obtained plasma samples from healthy controls and migraineurs were initially profiled. Subsequently, we profiled plasma samples from people with migraine (during and after a headache attack and healthy controls. Both MSD S-PLEX assays were transferred to Celerion where they were validated for analysis of clinical samples. Using the highly sensitive PACAP assay, we were able to reliably measure circulating levels of endogenous and administrated PACAP38in mouse and rat plasma. Additionally, using the highly sensitive CGRP assay, we were able to reliably measure circulating levels of endogenous and administrated CGRP in mouse and rat plasma. Furthermore, in the initial human samples, circulating CGRP and PACAP levels were not significantly different in healthy controls compared to people with migraine patients. However, ≥50% people with migraine showed increased circulating CGRP and PACAP levels during their attack period compared to post attack. Overall, people with migraine showed a 3 - 396% increase in one or both neuropeptides during their attack period compared to post attack. Circulating plasma CGRP and PACAP levels in healthy control subjects were consistent with previously measured levels. Our highly sensitive PACAP and CGRP assays were successful in measuring circulating levels of endogenous PACAP38 and CGRP in mouse and rat plasma. Our highly sensitive PACAP and CGRP assays were qualified for measurement of human CGRP and PACAP in healthy control and migraine samples. Plasma CGRP and PACAP levels are elevated in migraineurs during an attack period, and the increased plasma neuropeptide levels during an attack may help the differentiation of migraineurs from non-Migraineurs, or amongst people with migraines to help identify the best treatment for each patient.

Traumatic brain injury in children can lead to lifelong sequelae and disabilities. Identifying the mediators of the neuroinflammatory process resulting from head trauma is of great importance. We therefore explored the plasma levels of neurogenic inflammatory and vasodilator peptides in children with head trauma and their relationship with the clinical characteristics of the patients. Forty head-traumatized and 26 healthy children aged 2 months-7 years old were prospectively enrolled in the study. Demographic characteristics of patients and controls were recorded. Glasgow coma score (GCS), cause of trauma, computed tomography (CT) results, blood pressure, and pulse rate were recorded. Plasma calcitonin gene-related peptide (CGRP), pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38), vasoactive intestinal peptide (VIP), and substance P (SP) levels of patients and controls were measured by ELISA. Correlation and ROC analyses were carried out. The mean GCS of the patients was 14.8 ± 0.4, which was in the mild traumatic brain injury (mTBI) category. Plasma levels of CGRP, PACAP-38, VIP, and SP in patients with head trauma were significantly higher than controls. All peptide levels were significantly higher in CT-positive patients than in CT-negative patients who had only head trauma. Only CGRP was higher in female patients than in the males. A positive correlation was found between CGRP, PACAP-38, and SP levels, as well as between PACAP-38 and VIP. ROC analysis detected that these peptides had a diagnostic value in mTBI. Evaluation of pediatric patients with head trauma together with these neuropeptides may provide great benefits in deciding whether to perform radiography such as CT. However, due to the relatively low sensitivities in ROC analysis and small sample size, further studies are warranted before they may be used as a screening test to distinguish CT-positive from CT-negative patients.

Calcitonin Gene-related Peptide (CGRP), Vasoactive Intestinal Peptide (VIP) and Substance P (SP) are sensory neuropeptides which may alter cancer growth through modulation of chronic inflammation. We recently reported that SP suppresses breast cancer growth and metastasis through neuroimmune modulation. These neuropeptides are hydrolyzed by Neprilysin (NEP) to bioactive fragments. Decreased activity of NEP was reported in clear cell and chromophobe type renal cell carcinoma (RCC). It is however not known how the levels of neuropeptides hydrolyzed with NEP changes in RCC. Decrease activity of SP and CGRP containing sensory nerve endings was previously reported to increase cancer metastasis in animal models. It is however not known how peptidergic nerve endings are altered in RCC. Hence we here evaluated the levels of neuronal and non-neuronal neuropeptides and NEP activity in RCC including papillary type as well as neighboring uninvolved kidney. A cross-sectional study was conducted in 57 patients undergoing radical nephrectomy and diagnosed with RCC. NEP activity, levels and expression were determined using flourogenic substrate, western blot and qPCR respectively in freshly-frozen tissues. Immunohistochemical analyses were also performed. Neuronal and non-neuronal levels of CGRP, SP and VIP levels were determined using two-step acetic acid extraction. Levels and activity of NEP were markedly decreased in RCC regardless of subtype. Similar levels of VIP were detected in first and second extractions. VIP levels were higher in clear cell and papillary RCC compared to nearby kidney tissue. VIP levels of neighboring kidney tissue of papillary type RCC was significantly lower compared to kidney samples from clear cell RCC. CGRP levels were higher in second extraction. Similar to VIP levels, CGRP levels of neighboring kidney tissue from clear cell and chromophobe type RCC was significantly lower compared to corresponding tumor samples, an effect observed in the second extraction. VIP and CGRP levels of nearby kidney tissue varied subtype dependently demonstrating that different subtypes of RCC alter their local environment differently. Furthermore NEP-induce hydrolysis of VIP creates selective VPAC-1 receptor agonist which has anti-proliferative and anti-inflammatory effects. Hence loss of NEP activity may prevent anti-tumoral effects of VIP on RCC.

Secretion of calcitonin gene-related peptide (CGRP) from trigeminal nerves and vasoactive intestinal peptide (VIP) from parasympathetic nerves is involved in the pathophysiology of migraine and rhinosinusitis. Analysis of these neuropeptides in human saliva samples can be used as markers of trigeminal and parasympathetic nerve activity in patients between and during attacks as well as in response to specific treatments. To compare the amount of trigeminal sensory and parasympathetic nerve activation by measuring CGRP and VIP levels in the saliva of subjects experiencing noninfectious allergic rhinosinusitis, migraine with sinus symptoms, and no symptoms. Subjects were enrolled in three groups. Group A: subjects without a history of migraine, "sinus" headache, or allergic rhinosinusitis within the previous 6 months. Group B: subjects with chronic recurrent noninfectious rhinosinusitis and no history of migraine or "sinus" headache. Group C: subjects with self-described "sinus" headaches whose symptoms met International Headache Society diagnostic criteria (1.1 or 1.2) for migraine. The total amount of CGRP and VIP present in saliva collected under normal, pathological, and therapeutic conditions was determined by radioimmunoassay. Neuropeptide levels were normalized to total volume and amount of protein, and levels were correlated to onset and change in clinical symptoms. Total volume, total protein, and CGRP and VIP levels did not significantly change in saliva collected on consecutive days in the clinic and at the subject's home, respectively. No appreciable change in baseline salivary levels of CGRP and VIP was detected in control subjects. However, baseline salivary levels of CGRP and VIP were significantly elevated between attacks in allergic rhinosinusitis and migraine subjects compared to control values. For rhinosinusitis subjects, the amount of CGRP and VIP during attacks returned to baseline values following treatment with pseudoephedrine and relief of symptoms. Similarly, CGRP and VIP levels during a migraine headache were significantly reduced within 2 hours after sumatriptan treatment and reported symptom relief. Correlation of CGRP and VIP saliva levels observed in our study supports physiologically coordinated regulation of trigeminal and parasympathetic nerve activation in allergic rhinosinusitis and migraine patients between and during attacks as well as following treatment. Furthermore, our findings demonstrate that analysis of human saliva neuropeptides may provide a semiquantitative index of pathological and therapeutic states and, therefore, function as a clinical model for studying neuronal mechanisms involved in migraine and rhinosinusitis.

Pituitary adenylate cyclase-activating polypeptide-38 (PACAP38) and vasoactive intestinal polypeptide can provoke cluster headache attacks in up to half of cluster headache patients in their active phase. At present, it is unknown whether provoked attacks are mediated via calcitonin gene-related peptide or mast cell activation. All enrolled patients with cluster headache were randomly allocated to receive a continuous infusion of either PACAP38 (10 pmol/kg/min) or vasoactive intestinal polypeptide (8 pmol/kg/min) over 20 min. We collected clinical data and measured plasma levels of calcitonin gene-related peptide and markers of mast cell activation (tryptase and histamine) at fixed time points: at baseline (T0), at the end of the infusion (T20), 10 min after the infusion (T30), and 70 min after the infusion (T90). Blood was collected from episodic cluster headache patients in active phase (n = 14), episodic cluster headache patients in remission (n = 15), and chronic cluster headache patients (n = 15). At baseline, plasma levels of calcitonin gene-related peptide, tryptase, and histamine were not different among the three study groups. Plasma levels of calcitonin gene-related peptide (p = 0.7074), tryptase (p = 0.6673), or histamine (p = 0.4792) remained unchanged during provoked attacks compared to attack-free patients. Cluster headache attacks provoked by either PACAP38 or vasoactive intestinal polypeptide were not accompanied by alterations of plasma calcitonin gene-related peptide, tryptase or histamine. The provoked attacks may not be mediated by calcitonin gene-related peptide or mast cell activation.Trial Registration: The study is registered at ClinicalTrials.gov (NCT03814226).

Migraine is a neurovascular disorder that can be debilitating for individuals and society. Current research focuses on finding effective analgesics and management strategies for migraines by targeting specific receptors and neuropeptides. Nonetheless, newly approved calcitonin gene-related peptide (CGRP) monoclonal antibodies (mAbs) have a 50% responder rate ranging from 27 to 71.0%, whereas CGRP receptor inhibitors have a 50% responder rate ranging from 56 to 71%. To address the need for novel therapeutic targets, researchers are exploring the potential of another secretin family peptide, pituitary adenylate cyclase-activating polypeptide (PACAP), as a ground-breaking treatment avenue for migraine. Preclinical models have revealed how PACAP affects the trigeminal system, which is implicated in headache disorders. Clinical studies have demonstrated the significance of PACAP in migraine pathophysiology; however, a few clinical trials remain inconclusive: the pituitary adenylate cyclase-activating peptide 1 receptor mAb, AMG 301 showed no benefit for migraine prevention, while the PACAP ligand mAb, Lu AG09222 significantly reduced the number of monthly migraine days over placebo in a phase 2 clinical trial. Meanwhile, another secretin family peptide vasoactive intestinal peptide (VIP) is gaining interest as a potential new target. In light of recent advances in PACAP research, we emphasize the potential of PACAP as a promising target for migraine treatment, highlighting the significance of exploring PACAP as a member of the antimigraine armamentarium, especially for patients who do not respond to or contraindicated to anti-CGRP therapies. By updating our knowledge of PACAP and its unique contribution to migraine pathophysiology, we can pave the way for reinforcing PACAP and other secretin peptides, including VIP, as a novel treatment option for migraines.

Menopausal hot flash and calciotonin gene-related peptide; effect of Keishi-bukuryo-gan, a kampo medicine, related to plasma calciotonin gene-related peptide level

High plasma calcitonin gene-related peptide and serum pituitary adenylate cyclase-activating polypeptide levels in patients with neuropathic pain

AimSerum levels of Calcitonin Gene-Related Peptide (CGRP)-like immunoreactivity (CGRP-LI) in migraine patients before and after starting treatment with erenumab were measured to evaluate the association with clinical treatment response.MethodsBlood samples were collected from the cubital fossa before (T0) and 2–4 weeks after (T1) starting treatment with erenumab. Clinical response was monitored using a daily headache e-diary. Serum levels of CGRP-LI, assessed using radioimmunoassay, were compared between T0 and T1, correcting for migraine reduction. In addition, for both T0 and T1, linear regression models were constructed using migraine reduction as outcome and serum CGRP-LI as independent variable, corrected for age, gender and monthly migraine days (MMD) at baseline.ResultsSerum CGRP-LI did not differ between T0 and T1 (p = 0.30). However, there was an interaction between time and reduction in MMD (p = 0.01). Absolute reduction in MMD in the third month after treatment with erenumab was associated with serum CGRP-LI at T1, 2–4 weeks after starting treatment with erenumab (p = 0.003), but not with serum CGRP-LI at T0 (p = 0.24).ConclusionLower serum CGRP-LI 2–4 weeks after starting treatment with erenumab was associated with a higher reduction in migraine days after three months of treatment. Although the underlying mechanisms remain to be determined, this suggests that changes in CGRP levels, shortly after starting erenumab, are important for its clinical effect.

Increasing evidence suggests that vasoactive neuropeptides such as pituitary adenylate cyclase-activating polypeptide-38 (PACAP-38), substance P, calcitonin gene-related peptide, and vasoactive intestinal peptide are involved in the pathophysiology of migraine in adults, but their role in pediatric migraineurs remains unclear. We prospectively investigated plasma levels of these vasoactive neuropeptides in pediatric migraine patients without aura and compared the results with those of age-matched healthy controls. Thirty-eight children aged 6-18 years with migraine without aura and 20 age-matched control subjects were included in the study. Neuropeptides in plasma samples from the controls, and in either the ictal or interictal periods in pediatric migraine without aura, were measured using ELISA. PACAP-38 and vasoactive intestinal peptide levels in both ictal and interictal plasma were higher in the patients with pediatric migraine without aura than in the controls (p < 0.001), although calcitonin gene-related peptide and substance P levels remained unchanged. Otherwise, no significant difference was determined between ictal and interictal periods in terms of all neuropeptide levels. This study demonstrates increased plasma PACAP-38 and vasoactive intestinal peptide levels, but not calcitonin gene-related peptide and substance P levels, in pediatric patients with migraine during both attack and attack-free periods. The study findings suggest that PACAP-38 and vasoactive intestinal peptide may be implicated in the pathophysiology of migraine, particularly in pediatric migraineurs.