ATP-binding cassette subfamily B member 1 1236C/T polymorphism significantly affects the therapeutic outcome of tacrolimus in patients with refractory ulcerative colitis

A Review on the Immunomodulatory Mechanism of Acupuncture in the Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with a high prevalence and canceration rate. The immune disorder is one of the recognized mechanisms. Acupuncture is widely used to treat patients with IBD. In recent years, an increasing number of studies have proven the effectiveness of acupuncture in the treatment of IBD, and some progress has been made in the mechanism. In this paper, we reviewed the studies related to acupuncture for IBD and focused on the immunomodulatory mechanism. We found that acupuncture could regulate the innate and adaptive immunity of IBD patients in many ways. Acupuncture exerts innate immunomodulatory effects by regulating intestinal epithelial barrier, toll-like receptors, NLRP3 inflammasomes, oxidative stress, and endoplasmic reticulum stress and exerts adaptive immunomodulation by regulating the balance of Th17/Treg and Th1/Th2 cells. In addition, acupuncture can also regulate intestinal flora.

Research advances in the role and pharmaceuticals of ATP-binding cassette transporters in autoimmune diseases

Autoimmune diseases are caused by the immune response of the body to its antigens, resulting in tissue damage. The pathogenesis of these diseases has not yet been elucidated. Most autoimmune diseases cannot be cured by effective drugs. The treatment strategy is to relieve the symptoms of the disease and balance the body's autoimmune function. The abnormal expression of ATP-binding cassette (ABC) transporters is directly related to the pathogenesis of autoimmune diseases and drug therapy resistance, which poses a great challenge for the drug therapy of autoimmune diseases. Therefore, this paper reviews the interplay between ABC transporters and the pathogenesis of autoimmune diseases to provide research progress and new ideas for the development of drugs in autoimmune diseases.

The impact of cytochrome P450 3A genetic polymorphisms on tacrolimus pharmacokinetics in ulcerative colitis patients

Tacrolimus (Tac) is an effective remission inducer of refractory ulcerative colitis (UC). Gene polymorphisms result in interindividual variability in Tac pharmacokinetics. In this study, we aimed to examine the relationships between gene polymorphisms and the metabolism, pharmacokinetics, and therapeutic effects of Tac in patients with UC. Forty-five patients with moderate-to-severe refractory UC treated with Tac were retrospectively enrolled. Genotyping for cytochrome P450 (CYP) 3A4*1G, CYP3A5*3, CYP2C19*2, CYP2C19*3, nuclear receptor subfamily 1 group I member 2 (NR1I2)–25385C>T, ATP-binding cassette subfamily C member 2 (ABCC2)–24C>T, ABCC2 1249G>A, and ABCC2 3972C>T was performed. Concentration/dose (C/D) ratio, clinical therapeutic effects, and adverse events were evaluated. The C/D ratio of Tac in UC patients with the CYP3A4*1G allele was statistically lower than in those with the CYP3A4*1/*1 allele (P = 0.005) and significantly lower in patients with CYP3A5*3/*3 than in those with CYP3A5*1 (P < 0.001). Among patients with the CYP3A4*1G allele, the C/D ratio was significantly lower in patients with CYP3A5*1 than in those with CYP3A5*3/*3 (P = 0.001). Patients with the NR1I2–25385C/C genotype presented significantly more overall adverse events than those with the C/T or T/T genotype (P = 0.03). Although CYP3A4*1G and CYP3A5*3 polymorphisms were related to Tac pharmacokinetics, CYP3A5 presented a stronger effect than CYP3A4. The NR1I2–25385C/C genotype was related to the overall adverse events. The evaluation of these polymorphisms could be useful in the treatment of UC with Tac.

Advances in research of tacrolimus for treatment of inflammatory bowel disease

Traditional drugs for inflammatory bowel disease (IBD) include aminosalicylic acid preparations, glucocorticoids, and immunosuppressive agents such as thiopurine and cyclosporine. In recent ten years, the application of anti-tumor necrosis factor (anti-TNF) drugs has greatly improved the clinical remission of patients with IBD, but there are still some problems, such as no response, intolerance, and recurrence after withdrawal. In recent years, tacrolimus, as a new powerful immunosuppressive agent, has been used as a second-line therapeutic drug for IBD. At present, the tacrolimus induced short-term remission effect in IBD is relatively obvious, and it has been gradually used for treatment of IBD refractory to traditional drugs or anti-TNF drugs. A few studies have found that tacrolimus can be used safely for a long time under proper monitoring. However, there is little evidence of long-term efficacy and safety. In this paper, we review the latest advances in the treatment of IBD with tacrolimus and make a comparison with anti-TNF drugs.

Role of cytochrome P450 polymorphisms and functions in development of ulcerative colitis

Cytochromes P450s (CYPs) are terminal enzymes in CYP dependent monooxygenases, which constitute a superfamily of enzymes catalysing the metabolism of both endogenous and exogenous substances. One of their main tasks is to facilitate the excretion of these substances and eliminate their toxicities in most phase 1 reactions. Endogenous substrates of CYPs include steroids, bile acids, eicosanoids, cholesterol, vitamin D and neurotransmitters. About 80% of currently used drugs and environmental chemicals comprise exogenous substrates for CYPs. Genetic polymorphisms of CYPs may affect the enzyme functions and have been reported to be associated with various diseases and adverse drug reactions among different populations. In this review, we discuss the role of some critical CYP isoforms (CYP1A1, CYP2D6, CYP2J2, CYP2R1, CYP3A5, CYP3A7, CYP4F3, CYP24A1, CYP26B1 and CYP27B1) in the pathogenesis or aetiology of ulcerative colitis concerning gene polymorphisms. In addition, their significance in metabolism concerning ulcerative colitis in patients is also discussed showing a clear underestimation in genetic studies performed so far.

Individualized treatment based on CYP3A5 single-nucleotide polymorphisms with tacrolimus in ulcerative colitis

Background/Aims

The pharmacokinetics of tacrolimus (TAC) is known to be largely influenced by single-nucleotide polymorphisms (SNPs) in CYP3A5. Patients starting TAC require careful dose adjustment, owing to the wide range of optimal dosages, depending on their CYP3A5 expression status. Here, we evaluated whether individualization of TAC dosages based on CYP3A5 SNPs would improve its therapeutic efficacy in ulcerative colitis.

Methods

Twenty-one patients were prospectively treated, with their initial dosage adjusted according to their CYP3A5 status (0.1, 0.15, and 0.2 mg/kg/day for CYP3A5*3/*3, CYP3A5*1/*3, and CYP3A5*1/*1, respectively). Their clinical outcomes were compared with those of patients treated with a fixed dose (0.1 mg/kg/day).

Results

The first blood trough level of CYP3A5 expressors, CYP3A5*1/*3 or CYP3A5*1/*1, and the overall rate in achieving the target blood trough level within a week in the individualized-dose group were significantly higher than those in the fixed-dose group (5.15±2.33 ng/mL vs. 9.63±0.79 ng/mL, P=0.035 and 12.5% vs. 66.7%, P=0.01). The remission rate at 2 weeks in the expressors was as high as that in the nonexpressors, CYP3A5*3/*3, in the individualized-dose group.

Conclusions

Individualized TAC treatment is effective against ulcerative colitis regardless of the CYP3A5 genotype.

Tacrolimus Dose Optimization Strategy for Refractory Ulcerative Colitis Based on the Cytochrome P450 3A5 Polymorphism Prediction Using Trough Concentration after 24 Hours

BACKGROUND

In the tacrolimus treatment for refractory ulcerative colitis (UC), dose adjustment is necessary because the required doses to keep appropriate drug concentrations are significantly different among individuals. Cytochrome P450 (CYP) 3A5 polymorphism affects tacrolimus blood concentrations. However, it is difficult to obtain genetic information in real clinical practice. In the present study, we investigated possible factors that may predict CYP3A5 polymorphism and proposed a dose optimization strategy based on the obtained predicting factors.

SUMMARY

We retrospectively analyzed 41 patients who underwent remission induction therapy with tacrolimus for UC in our hospital. First, we performed a correlation analysis of CYP3A5 polymorphism and pharmacokinetics. In the CYP3A5 non-expressers, the dose of tacrolimus (mg/kg) was lower and dose-adjusted trough levels (ng/mL per mg/kg) were higher compared with those in expressers. Next, we investigated factors that could predict CYP3A5 polymorphism. Trough concentration 24 h following tacrolimus administration was extracted as a significant factor. When the trough cutoff value at 24 h was set to 2.6 ng/mL, sensitivity and specificity for estimation of CYP3A5 polymorphism were 63 and 96% respectively. Therefore, when the trough concentration 24 h after administration is ≤2.6 ng/mL, the patient can be estimated as a CYP3A5 expresser and an increase in dose should be proposed. Key Message: The trough concentration 24 h after the first tacrolimus administration appears to be a useful predictor of -CYP3A5 polymorphism. Performing dose optimization strategy based on the prediction of CYP3A5 polymorphism can lead to earlier and safer remission induction.

Population Pharmacokinetics and Adverse Events of Erlotinib in Japanese Patients with Non-small-cell Lung Cancer: Impact of Genetic Polymorphisms in Metabolizing Enzymes and Transporters

Determinants of interindividual variability in erlotinib pharmacokinetics (PK) and adverse events remain to be elucidated. This study with 50 Japanese non-small-cell lung cancer patients treated with oral erlotinib at a standard dose of 150 mg aimed to investigate whether genetic polymorphisms affect erlotinib PK and adverse events. Single nucleotide polymorphisms (SNPs) in genes encoding metabolizing enzymes (CYP1A1, CYP1A2, CYP2D6, CYP3A4, CYP3A5, UGT1A1, UGT2B7, GSTM1, and GSTT1) or efflux transporters (ABCB1, and ABCG2) were analyzed as covariates in a population PK model. The ABCB1 1236C>T (rs1128503) polymorphism, not ABCB1*2 haplotype (1236TT-2677TT-3455TT, rs1128503 TT-rs2032582 TT-rs1045642 TT), was a significant covariate for the apparent clearance (CL/F), with the TT genotype showing a 29.4% decrease in CL/F as compared with the CC and the CT genotypes. A marginally higher incidence of adverse events (mainly skin rash) was observed in the TT genotype group; however, patients with high plasma erlotinib exposure did not always experience skin rash. None of the other SNPs affected PK or adverse events. The ABCB1 genotype is a potential predictor for erlotinib adverse events. Erlotinib might be used with careful monitoring of adverse events in patients with ABCB1 polymorphic variants.

ABCB1 gene polymorphism associated with clinical factors can predict drug-resistant tuberculosis

Polymorphism in the ABCB1 gene encoding P-glycoprotein, a transmembrane drug efflux pump, contributes to drug resistance and has been widely studied. However, their association with rifampicin and ethambutol resistance in tuberculosis (TB) patients is still unclear. Genotype/allele/haplotype frequencies in c.1236C > T (rs1128503), c.2677G > T/A (rs2032582), and c.3435C > T (rs1045642) were obtained from 218 patients. Of these, 80 patients with rifampicin and/or ethambutol resistance were selected as the case group and 138 patients were selected for the control group through the results of their culture and drug-sensitive tests. Patients aged <18 years and HIV-positive serologic tests were excluded. ABCB1 polymorphisms were determined using a PCR direct-sequencing approach, and restriction fragment length polymorphism (RFLP). A nomogram was constructed to simulate a combined prediction of the probability of anti-TB drug resistance, with factors including genotype c.1236C > T (rs1128503) (P=0.02), clinical form (P=0.03), previous treatment (P=0.01), and skin color (P=0.03), contributing up to 90% chance of developing anti-TB drug resistance. Considering genotype analyses, CT (rs1128503) demonstrated an increased chance of anti-TB drug resistance (odds ratio (OR): 2.34, P=0.02), while the analyses for ethambutol resistance revealed an association with a rare A allele (rs2032582) (OR: 12.91, P=0.01), the haplotype TTC (OR: 5.83, P=0.05), and any haplotype containing the rare A allele (OR: 7.17, P=0.04). ABCB1 gene polymorphisms in association with others risk factors contribute to anti-TB drug resistance, mainly ethambutol. The use of the nomogram described in the present study could contribute to clinical decision-making prior to starting TB treatment.