Association of Valproic Acid and Its Main Metabolites' Plasma Concentrations with Clinical Outcomes among Epilepsy Patients: A 10-Year Retrospective Study Based on Therapeutic Drug Monitoring.

Valproic acid (VPA) is a first-line antiepileptic drug with broad efficacy. Due to significant individual differences in its metabolism, therapeutic drug monitoring is commonly used. However, the recommended therapeutic range (50-100 µg/mL) is inadequate for predicting clinical outcomes. Additionally, the relationship between VPA metabolites and clinical outcomes remains unclear. In this retrospective study, 485 Chinese Southern Han epilepsy patients receiving VPA monotherapy were analyzed after reaching steady-state levels. Plasma concentrations of VPA and its five main metabolites were determined by liquid chromatography-mass spectrometry (LC-MS). We assessed the relevance of the recommended therapeutic VPA range for clinical outcomes and explored the association between VPA/metabolites levels and treatment efficacy/adverse effects. Vitro experiments were conducted to assess 4-ene-VPA hepatotoxicity. The therapeutic range of VPA exhibited no significant correlation with clinical outcomes, and plasma concentrations of VPA failed to serve as predictive indicators for treatment response/adverse effects. Treatment responders had higher 2-PGA concentrations (median, 26.39 ng/mL versus 13.68 ng/mL), with a threshold of 36.5 ng/mL for optimal epilepsy treatment. Patients with abnormal liver function had a higher 4-ene-VPA median concentration (6.41 µg/mL versus 4.83 µg/mL), and the ratio of 4-ene-VPA to VPA better predicted VPA-induced hepatotoxicity (area under the curve, 0.718) than 4-ene-VPA concentration. Vitro experiments revealed that 4-ene-VPA was more hepatotoxic than VPA in HepaRG and L02 cell lines. Total plasma VPA concentration does not serve as a predictor of clinical outcomes. 2-PGA concentrations may be associated with efficacy, whereas the ratio of 4-ene-VPA to VPA may be considered a better biomarker (threshold 10.03%) for VPA-induced hepatotoxicity. SIGNIFICANCE STATEMENT: This was the first and largest observational cohort in China to explore the relationship between patients' parent and metabolites concentrations of VPA and clinical outcomes during the maintenance of VPA monotherapy in epileptic patients. This study provided feasible references of VPA for epilepsy clinical treatment with a larger sample of patients compared with previous studies for a more definitive conclusion based on real-world situations. We found two potential biomarkers in predicting efficacy and liver injury, respectively. This breakthrough has the potential to assist in the rational use of VPA.

HLA Risk Alleles in Aromatic Antiepileptic Drug-Induced Maculopapular Exanthema.

To characterize human leukocyte antigen (HLA) loci as risk factors in aromatic antiepileptic drug-induced maculopapular exanthema (AED-MPE). A case-control study was performed to investigate HLA loci involved in AED-MPE in a southern Han Chinese population. Between January 2007 and June 2019, 267 patients with carbamazepine (CBZ), oxcarbazepine (OXC), or lamotrigine (LTG) associated MPE and 387 matched drug-tolerant controls from six centers were enrolled. HLA-A/B/C/DRB1 genotypes were determined using sequence-based typing. Potential risk alleles were validated by meta-analysis using data from different populations and in silico analysis of protein-drug interactions. HLA-DRB1*04:06 was significantly associated with OXC-MPE (p = 0.002, p c = 0.04). HLA-B*38:02 was associated with CBZ-MPE (p = 0.03). When pooled, HLA-A*24:02, HLA-A*30:01, and HLA-B*35:01 additionally revealed significant association with AED-MPE. Logistic regression analysis showed a multiplicative interaction between HLA-A*24:02 and HLA-B*38:02 in CBZ-MPE. Meta-analysis of data from different populations revealed that HLA-24*:02 and HLA-A*30:01 were associated with AED-MPE (p = 0.02 and p = 0.04, respectively). In silico analysis of protein-drug interaction demonstrated that HLA-A*24:02 and HLA-A*30:01 had higher affinities with the three aromatic AEDs than the risk-free HLA-A allele. HLA-DRB1*04:06 showed relatively specific high affinity with S-monohydroxy derivative of OXC. HLA-DRB1*04:06 is a specific risk allele for OXC-induced MPE in the Southern Han Chinese. HLA-A*24:02, possibly HLA-A*30:01, are common risk factors for AED-MPE. The multiplicative risk potential between HLA-A*24:02 and HLA-B*38:02 suggests that patients with two risk alleles are at greater risk than those with one risk allele. Inclusion of these HLA alleles in pre-treatment screening would help estimating the risk of AED-MPE.

Up-regulated microRNA-199b-3p represses the apoptosis of cerebral microvascular endothelial cells in ischemic stroke through down-regulation of MAPK/ERK/EGR1 axis.

MicroRNAs (miRNAs) have emerged as key mediators of posttranscriptional gene silencing in both pathogenic and pathological aspects of ischemic stroke biology. Therefore, the purpose of present study was to explore the effect of microRNA-199b-3p (miR-199b-3p) on the cerebral microvascular endothelial cells (CMECs) in middle cerebral artery occlusion-reperfusion (MCAO-R) mice by regulating MAPK/ERK/EGR1 axis. Mice were used to establish MCAO-R models and to measure the expression of miR-199b-3p and the MAPK/ERK/EGR1 axis-related genes. CMECs were extracted from the MCAO-R mice. A series of mimic or inhibitor for miR-199b-3p, or U0126 (an inhibitor for the MAPK/ERK/EGR1 axis) were introduced to treat these CMECs. The levels of miR-199b-3p and MAPK/ERK/EGR1 axis-related genes in tissues and cells were detected. The effects miR-199b-3p on the process of CMECs, including cell viability, cell cycle and cell apoptosis were evaluated. miR-199b-3p expressed poorly in the brain tissues after MCAO-R, along with activated MAPK/ERK/EGR1 axis and increased CMECs apoptosis. CMECs transfected with miR-199b-3p mimics and U0126 manifested with increased cell viability, more cells arrested at the S stage, and inhibited apoptosis of CMECs. In conclusion, these key results demonstrated up-regulated miR-199b-3p could protect mice against ischemic stroke by inhibiting the apoptosis of CMECs through blockade of MAPK/ERK/EGR1 axis.

ABCC2 rs2273697 is associated with valproic acid concentrations in patients with epilepsy on valproic acid monotherapy.

Valproic acid (VPA), a widely used antiepileptic drug, is characterized by intensive inter-individual variability in concentration. Both efflux and influx transporters are reported to play important roles in the disposition of VPA, however, no comprehensive investigation into the association of the single nucleotide polymorphism (SNP) in ABC/SLC families with VPA concentration are reported. In the present study, we investigated the association of 12 SNPs in ABCC2, ABCC4, ABCG2, MCT1, MCT2, and OATP2B1 in 187 Chinese patients with epilepsy on VPA monotherapy with the trough concentrations of VPA. The data showed that VPA concentration in patients with ABCC2 rs2273697 AA genotype was significantly higher than that in those with GA+GG genotypes (p=0.000). The findings of the present study suggest that ABCC2 polymorphisms influence VPA concentrations in patients with epilepsy on VPA monotherapy, which may affect the treatment outcomes.

HLA-A*24:02 as a common risk factor for antiepileptic drug-induced cutaneous adverse reactions.

OBJECTIVE: To investigate the involvement of human leukocyte antigen (HLA) loci in aromatic antiepileptic drug-induced cutaneous adverse reactions. METHODS: A case-control study was performed to detect HLA loci involved in aromatic antiepileptic drug-induced Stevens-Johnson syndrome in a southern Han Chinese population. Between January 1, 2006, and December 31, 2015, 91 cases of Stevens-Johnson syndrome induced by aromatic antiepileptic drugs and 322 matched drug-tolerant controls were enrolled from 8 centers. Important genotypes were replicated in cases with maculopapular eruption and in the meta-analyses of data from other populations. Sequence-based typing determined the HLA-A, HLA-B, HLA-C, and HLA-DRB1 genotypes. RESULTS: HLA-B*15:02 was confirmed as strongly associated with carbamazepine-induced Stevens-Johnson syndrome (p = 5.63 × 10-15). In addition, HLA-A*24:02 was associated significantly with Stevens-Johnson syndrome induced by the aromatic antiepileptic drugs as a group (p = 1.02 × 10-5) and by individual drugs (carbamazepine p = 0.015, lamotrigine p = 0.005, phenytoin p = 0.027). Logistic regression analysis revealed a multiplicative interaction between HLA-B*15:02 and HLA-A*24:02. Positivity for HLA-A*24:02 and/or HLA-B*15:02 showed a sensitivity of 72.5% and a specificity of 69.0%. The presence of HLA-A*24:02 in cases with maculopapular exanthema was also significantly higher than in controls (p = 0.023). Meta-analysis of data from Japan, Korea, Malaysia, Mexico, Norway, and China revealed a similar association. CONCLUSIONS: HLA-A*24:02 is a common genetic risk factor for cutaneous adverse reactions induced by aromatic antiepileptic drugs in the southern Han Chinese and possibly other ethnic populations. Pretreatment screening is recommended for people in southern China.

[Effects of carbamazepine on plasma concentrations of valproic acid and its toxic metabolite in epileptic patients].

To investigate the effects of carbamazepine (CBZ) on the plasma concentrations of valproic acid (VPA) and its toxic metabolite 2-propyl-4-pentenoic acid (4-ene VPA) in epileptic patients, the plasma concentrations of VPA and 4-ene VPA were determined, and the effect of CBZ on pharmacokinetics of VPA was evaluated. All patients had been divided into two groups (VPA group, n = 87; and VPA+CBZ group, n = 19). As compared to VPA group, the combination of CBZ significantly (P < 0.01) decreased the trough concentration of VPA [VPA group, (69.5 +/- 28.8) microg x mL(-1); VPA+CBZ group, (46.3 +/- 25.6) microg x mL(-1)] and does-adjusted VPA trough concentration [VPA group, (4.89 +/- 2.21) microg x mL(-1) x mg(-1) x kg(-1); VPA+CBZ group, (3.14 +/- 1.74) microg x mL(-1) x mg(-1) x kg(-1)]. However, the addition of CBZ did not influence the concentration of 4-ene VPA. The present study revealed that coadministration of CBZ can reduce VPA plasma concentration and may impact VPA clinical effect, therefore therapeutic drug mornitoring of VPA should be used when combined use of CBZ and VPA.

Polycystic ovary syndrome in patients with epilepsy: a study in 102 Chinese women.

PURPOSE: The incidence of polycystic ovary syndrome (PCOS) increases in women with epilepsy (WWE), which appears to vary with ethnicity. This study was conducted to determine the incidence and risk factors of PCOS in Chinese WWE. METHODS: The study was carried out in 102 of 139 Chinese WWE at reproductive ages, with 32 receiving valproic acid (VPA), 40 receiving other antiepileptic drugs (AEDs), and 30 without AEDs therapy. PCOS was defined as having 2 or more of the following components: polycystic ovaries, hyperandrogenism, and amenorrhoea or oligomenorrhoea (a/oligomenorrhoea). RESULTS: One or more isolated components of PCOS were found in 56 (54.9%) patients, with 29 (28.4%) having polycystic ovaries, 20 (19.6%) with a/oligomenorrhea, 7 (6.9%) with hyperandrogenism, and 13 (12.7%) with defined PCOS. Their average age at the start of seizure was 13.8±6.5 years, younger than that of patients without these disorders (16.9±8.6 years, p<0.05). VPA therapy increased the incidence of PCOS (11/32, 34.4%), in addition to increased blood levels of testosterone and luteinizing hormone (LH) as well as LH to FSH (follicle-stimulating hormone) ratio. No significant relationship was found between the incidence of PCOS and the type, duration, or frequency of seizures in these WWE. CONCLUSION: There is an increased incidence of PCOS in Chinese WWE at reproductive ages, by more than 2 times of that in the general population. Risk factors include seizures starting at a young age and VPA therapy.

Simultaneous determination of valproic acid and 2-propyl-4-pentenoic acid for the prediction of clinical adverse effects in Chinese patients with epilepsy.

Valproic acid (VPA) is a well-established anticonvulsant drug that has been increasingly used in the treatment of many forms of generalized epilepsy. Although there are many reports of adverse effects of VPA, studies focusing on the concentration-response relationships of VPA and its metabolites in patients with epilepsy are extremely limited. In this study, a rapid and specific high performance liquid chromatography-ultraviolet (HPLC-UV) method to simultaneously detect the concentrations of VPA and its major hepatotoxic metabolite 2-propyl-4-pentenoic acid (4-ene VPA) in human plasma has been established, using 2,4'-dibromoacetophenone and octanoic acid as the derivatization reagent and internal standard, respectively. This method was used to analyze plasma samples (n=64) of Chinese patients with epilepsy. The results revealed that 4-ene VPA concentrations in Chinese patients were much higher than those in patients in other countries such as United States and Iran. Significant correlations between aspartate aminotransferase (AST), alanine aminotransferase (ALT) and 4-ene VPA concentration suggest that the simultaneous determination of VPA and 4-ene VPA is an effective tool for the prediction of clinical hepatotoxicity in epileptic patients. Furthermore, the present study describes a less costly and complex technique for the clinical monitoring of VPA plasma levels and the risk of hepatotoxicity which may be of particular interest in developing countries like China.

Association between HLA-B*1502 allele and carbamazepine-induced severe cutaneous adverse reactions in Han people of southern China mainland.

Previous studies have found a strong association between HLA-B*1502 and carbamazepine-induced Stevens-Johnson syndrome in Asian areas including Taiwan, Hongkong and Thailand. This study explores the association between HLA-B*1502 allele and carbamazepine-induced cutaneous adverse reactions in Han Chinese of southern China mainland, and find the genetic marker that can predict carbamazepine-induced cutaneous adverse reactions. HLA-B*1502 allele genotyping was performed by a polymerase chain reaction-sequence specific primers (PCR-SSP) method in 48 Han Chinese subjects who had carbamazepine-induced cutaneous adverse reactions, including 9 severe cutaneous adverse reaction patients with Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN) and 39 cutaneous adverse reaction patients with maculopapular eruption (MPE). Meanwhile 80 carbamazepine-tolerant controls and 62 healthy individuals were also tested. The frequency of HLA-B*1502 allele among SJS/TEN patients (100%) is significantly higher than carbamazepine-tolerant controls (13.75%, P<0.001) and healthy individuals (17.74%, P<0.001). But the frequency between MPE patients and carbamazepine-tolerant controls (25.64% vs.13.75%, P=0.110) did not have any significant difference. The data showed that HLA-B*1502 allele is strongly associated with carbamazepine-induced SJS/TEN but not MPE in Han Chinese of southern China mainland.

Analyzing clinical and electrophysiological characteristics of Paroxysmal Dyskinesia.

The classification, clinical and electrophysiological characteristics, treatment outcome and pathogenesis of paroxysmal dyskinesia were summarized and analyzed. Paroxysmal dyskinesia was classified into three types. Different types had different incentives in clinical practice. Patients were mostly male adolescents, and the attacks, which were in various forms, manifested as dysmyotonia of choreoathetosis, body torsion and facemaking; no disturbance of consciousness during attacks. Electroencephalogram and other examinations showed no specific abnormalities during both the attacks and interictal period. Paroxysmal dyskinesia was an independent disease and different from epilepsy.