Mucin 1 promotes salivary gland cancer cell proliferation and metastasis by regulating the epidermal growth factor receptor signaling pathway.

Background/purpose: Salivary gland cancer (SGC) is the common malignant tumor of the head and neck region with poor prognosis. Mucin 1 (MUC1) has been reported to be associated with the development of cancer. However, whether MUC1 contributed to the progression of SGC remains to be explored. Materials and methods: Immunohistochemical analysis was used to explore the expression levels of MUC1 in SGC tissues. Cell proliferation, colony formation, wound healing, transwell, and xenograft assays were performed to examine the effects of MUC1 on SGC in vitro and in vivo. Results: We found that the expression level of MUC1 was significantly upregulated in SGC tissues, and the expression level of MUC1 was significantly correlated with lymph node metastasis and TNM stage of SGC. Further exploration demonstrated that MUC1 knockdown drastically inhibited, while its overexpression promoted, cell growth, colony formation, migration, and invasion abilities of SGC cells in vitro. MUC1 knockdown significantly inhibited tumor growth in vivo, and vice versa. More importantly, we found that MUC1 promotes malignant phenotypes of SGC cells by regulating the epidermal growth factor receptor (EGFR) signaling pathway. Conclusion: Our results revealed that MUC1 promotes the development of SGC by mediating the EGFR signaling pathway, which highlights the potential therapeutic target of MUC1/ EGFR in SGC.

Risk of skin cancer in kidney, liver and heart recipients: A nationwide population-based study in Taiwan.

Background Previous population-based studies in western countries had revealed increased skin cancer risk among transplant recipients compared to the general population. However, population-based studies in Asia on skin cancer among recipients of different transplanted organs were lacking in the literature. Aims This study aims to estimate skin cancer risk among recipients in Taiwan, examine the association between each specific type of skin cancer and each type of transplanted organ, and compare skin cancer risk between different immunosuppressive regimens. Methods This population-based retrospective cohort study identified 7550 patients with heart, lung, kidney or liver transplantation and 30,200 controls matched for gender, age and comorbidity index from the National Health Insurance Research Database in Taiwan between 2000 and 2015. Using multivariable Cox proportional hazard models, we estimated the hazard ratios and 95% confidence intervals for the correlation of skin cancer with organ transplantation as well as immunosuppressive regimen. Results Organ transplant recipients in Taiwan had an increased risk of skin cancer with adjusted hazard ratios of 4.327 (95% confidence intervals 2.740-6.837, P < 0.001), with the greatest risk, observed among heart recipients (adjusted hazard ratios 6.348, 95% confidence intervals 3.080-13.088, P < 0.001). The risk of non-melanoma skin cancer and melanoma was 4.473 (95% confidence intervals 2.568-7.783, P < 0.001) and 3.324 (95% confidence intervals 1.300-8.172, P < 0.001), respectively. When comparing immunosuppressants, those with calcineurin inhibitors carried the highest risk of skin cancer (adjusted hazard ratios 4.789, 95% confidence intervals 3.033-7.569, P < 0.001), followed by those with antimetabolites (adjusted hazard ratios 4.771, 95% confidence intervals 3.025-7.541, P < 0.001). Limitations We could not evaluate confounding behavioural risk factors of skin cancers that were not documented in the database, nor could we recognize patients' compliance with immunosuppressants. Conclusion Organ recipients have a greater risk of skin cancer. Clinicians should inform recipients of the importance of photoprotection and regular dermatologic follow-up.

Stevens-Johnson syndrome and toxic epidermal necrolysis associated with increased risk of developing psychiatric disorders: A retrospective population-based cohort study in Taiwan.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening adverse reactions to drugs and psychological sequelae are also observed to follow the trauma of widespread epidermal necrolysis. To delineate the association between SJS and TEN, and psychiatric disorders, we conducted a retrospective population-based cohort study by including 212 patients diagnosed with first-time SJS or TEN in Taiwan between 2000 and 2013 and 669 population controls. Adjusted hazard ratios were calculated after adjusting for sex, age, comorbidity in the form of Charlson comorbidity index, and facility level of care. Overall, SJS or TEN was associated with an increased risk of developing psychiatric disorders including schizophrenia, major depressive disorder, mania, anxiety, and bipolar with an adjusted hazard ratio of 1.392 (95% CI, 1.192-1.625; p < 0.001). Particularly, the adjusted hazard ratios of psychiatric disorders were 1.290 (95% CI, 1.105-1.506; p < 0.001) for SJS and 1.855 (95% CI, 1.587-2.167; p < 0.001) for TEN.

Comparison of outcomes for percutaneous coronary intervention in men and women with unprotected left main disease.

BACKGROUND: Percutaneous coronary intervention (PCI) in patients with unprotected left main coronary artery disease (ULMCAD) is increasing strategy in coronary artery patients. However, there is a lack of knowledge on the impact of sex on outcomes of patients undergoing ULMCAD PCI. METHODS: From January 2004 to December 2015, there were 3,960 patients undergoing ULMCAD PCI at our institution, including 3,121 (78.8%) men and 839 (21.2%) women. The clinical outcome included the incidence of major adverse cardiac events (MACE) (the composite of all-cause death, myocardial infarction (MI), and revascularization), all-cause death, MI, revascularization at three years follow-up. RESULTS: Compared with men, women had not significantly different MACE (14.7% vs. 14.6%, P = 0.89, all-cause death (3.5% vs. 3.7%, P = 0.76), MI (5.0% vs. 4.3%, P = 0.38), revascularization (9.1% vs. 8.9%, P = 0.86), respectively. After adjustment, rates of MACE (HR = 1.49; 95% CI: 1.24-1.81;P < 0.0001) and all-cause death (HR = 1.65; 95% CI: 1.09-2.48; P = 0.017) occurred more frequently in male patients, as well as revascularization (HR = 1.46; 95% CI: 1.16-1.85;P = 0.001). CONCLUSION: In this analysis, compared to men, women undergoing ULMCAD PCI have better outcomes of MACE, all-cause death, and revascularization.

Interferon regulatory factor transcript levels correlate with clinical outcomes in human glioma.

Members of the interferon regulatory factor (IRF) gene family are crucial regulators of type I interferon signaling, which may play a role in the resistance of glioma to immune checkpoint blockade. However, the expression profiles, potential functions, and clinical significance of IRF family members remain largely unknown. Here, we examined IRF transcript levels and clinicopathological data from glioma patients using several bioinformatic databases, including ONCOMINE, GEPIA, TCGA, and cBioPortal. We found that IRF1, IRF2, IRF5, IRF8 and IRF9 were significantly upregulated in glioma compared to normal brain tissue. Higher IRF1, IRF2, IRF3, IRF4, IRF5, IRF7, IRF8 and IRF9 mRNA levels correlated with more advanced tumor grades and poorer outcomes. Moreover, although IRFs mutation rates were low (ranging from 0.5% to 2.3%) in glioma patients, genetic alterations in IRFs were associated with more favorable patient survival. Functional analysis showed that IRFs participated in glioma pathology mainly through multiple inflammation- and immunity-related pathways. Additionally, correlations were identified between IRFs and infiltration of immune cells within glioma tissues. Collectively, these results indicate that IRF family members, including IRF1, IRF2, IRF5, IRF8 and IRF9, may serve as prognostic biomarkers and indicators of immune status in glioma patients.

Impacts of smoking status on the clinical outcomes of coronary non-target lesions in patients with coronary heart disease: a single-center angiographic study.

BACKGROUND: Coronary atherosclerotic plaque could go through rapid progression and induce adverse cardiac events. This study aimed to evaluate the impacts of smoking status on clinical outcomes of coronary non-target lesions. METHODS: Consecutive patients with coronary heart disease who underwent two serial coronary angiographies were included. All coronary non-target lesions were recorded at first coronary angiography and analyzed using quantitative coronary angiography at both procedures. Patients were grouped into non-smokers, quitters, and smokers according to their smoking status. Clinical outcomes including rapid lesion progression, lesion re-vascularization, and myocardial infarction were recorded at second coronary angiography. Multivariable Cox regression analysis was used to investigate the association between smoking status and clinical outcomes. RESULTS: A total of 1255 patients and 1670 lesions were included. Smokers were younger and more likely to be male compared with non-smokers. Increase in percent diameter stenosis was significantly lower (2.7 [0.6, 7.1] % vs. 3.5 [0.9, 8.9]%) and 3.4 [1.1, 7.7]%, P = 0.020) in quitters than those in smokers and non-smokers. Quitters tended to have a decreased incidence of rapid lesions progression (15.8% [76/482] vs. 21.6% [74/342] and 20.6% [89/431], P = 0.062), lesion re-vascularization (13.1% [63/482] vs. 15.5% [53/432] and 15.5% [67/431], P = 0.448), lesion-related myocardial infarction (0.8% [4/482] vs. 2.6% [9/342] and 1.4% [6/431], P = 0.110) and all-cause myocardial infarction (1.9% [9/482] vs. 4.1% [14/342] and 2.3% [10/431], P = 0.128) compared with smokers and non-smokers. In multivariable analysis, smoking status was not an independent predictor for rapid lesion progression, lesion re-vascularization, and lesion-related myocardial infarction except that a higher risk of all-cause myocardial infarction was observed in smokers than non-smokers (hazards ratio: 3.00, 95% confidence interval: 1.04-8.62, P = 0.042). CONCLUSION: Smoking cessation mitigates the increase in percent diameter stenosis of coronary non-target lesions, meanwhile, smokers are associated with increased risk for all-cause myocardial infarction compared with non-smokers.

Lithium toxicity with prolonged neurologic sequelae following sleeve gastrectomy: A case report and review of literature.

RATIONALE: Lithium is the first-line medication for bipolar disorder, given a narrow therapeutic window of 0.8 to 1.2 mEq/L. Change of lithium pharmacokinetics following bariatric surgery may lead to lithium toxicity, which is particularly concerned. PATIENT CONCERNS: We presented a 39-year-old man with morbid obesity and bipolar affective disorder for 20 years, who was treated with lithium. He developed serious lithium toxicity following sleeve gastrectomy and prolonged neurologic sequelae. DIAGNOSES: He suffered from persistent watery diarrhea, general weakness, and then drowsy consciousness. Lithium level was checked immediately to be 3.42 mEq/L and lithium toxicity was diagnosed. INTERVENTIONS: After 3 courses of hemodialysis, his serum lithium level subsequently declined to 0.63 mEq/L, while his consciousness returned normal. Lithium was replaced by lamotrigine. OUTCOMES: The patient was discharged thirty-five days after admission, while his serum lithium declined to 0.06 mEq/L. Neurologic sequelae were noted by muscle weakness and pain sensation in both feet. The nerve conduction test revealed sensorimotor polyneuropathy with conduction block. He was advised to keep a passive range of motion exercise. LESSONS: Although the consensus guideline remains lacking, our report reviewed cases of relevance in the literature and highlighted the awareness of the potential risk of lithium toxicity following bariatric surgery. We suggest close monitoring of the lithium levels and perhaps a dosage adjustment for the postoperative period.

Pharmacogenomics study on cadherin 2 network with regard to HIV infection and methadone treatment outcome.

Heroin dependent patients have a high incidence of HIV infection. In contrast to the gene expression method, we developed a systemic correlation analysis method built upon the results of pharmacogenomics study in a methadone maintenance treatment (MMT) cohort consisting of 344 Taiwanese heroin dependent patients. We identified genetic variants and their encoding proteins that may be involved with HIV infection and MMT treatment outcome. Cadherin 2 (CDH2) genetic determinants were identified through the genome-wide pharmacogenomic study. We found significant correlations among HIV infection status, plasma levels of CDH2, cytokine IL-7, ADAM10, and the treatment responses to methadone. Two single nucleotide polymorphisms located within CDH2 gene showed associations with blood pressure and plasma CDH2 concentration. Plasma concentration of CDH2 showed correlations with the level of cytokine IL-7, status of HIV infection, and urine morphine test result. Plasma level of IL-7 was correlated with corrected QT interval (QTc) and gooseflesh skin withdrawal symptom score, while level of ADAM10 was correlated with plasma concentrations of vitamin D metabolite, nicotine metabolite, and R-methadone. The results suggest a novel network involving HIV infection and methadone treatment outcome.

In Situ Release of VEGF Enhances Osteogenesis in 3D Porous Scaffolds Engineered with Osterix-Modified Adipose-Derived Stem Cells.

Adipose-derived stem cells (ADSCs) can differentiate into various cell types and thus have great potential for regenerative medicine. Herein, rat ADSCs were isolated; transduced with lentiviruses expressing Osterix (Osx), a transcriptional factor essential for osteogenesis. Osx overexpression upregulated key osteogenesis-related genes, such as special AT-rich binding protein 2, alkaline phosphatase, osteocalcin, and osteopontin, at both mRNA and protein levels. In addition, mineral nodule formation and alkaline phosphatase activity were enhanced in Osx-overexpressing ADSCs. The expression of dickkopf-related protein 1, a potent Wnt signaling pathway inhibitor, was also increased, whereas that of ß-catenin, an intracellular signal transducer in the Wnt pathway, was decreased. ß-catenin expression was partially recovered by treatment with lithium chloride, a canonical Wnt pathway activator. The Osx-expressing ADSCs were then combined with 3D gelatin-coated porous poly(ɛ-caprolactone) scaffolds with a unique release prolife of entrapped recombinant human vascular endothelial growth factor (VEGF). The controlled release of VEGF promoted osteogenic differentiation capacity in vitro. When the scaffold-ADSC complexes were transplanted into rat calvarial critical-sized defects, more bone formed on the gelatin/VEGF-coated scaffolds than on other scaffold types. Taken together, the results indicate that, Osx-overexpression promotes ADSCs' osteogenesis both in vitro and in vivo, which could be enhanced by release of VEGF.

Genome-Wide Pharmacogenomic Study on Methadone Maintenance Treatment Identifies SNP rs17180299 and Multiple Haplotypes on CYP2B6, SPON1, and GSG1L Associated with Plasma Concentrations of Methadone R- and S-enantiomers in Heroin-Dependent Patients.

Methadone maintenance treatment (MMT) is commonly used for controlling opioid dependence, preventing withdrawal symptoms, and improving the quality of life of heroin-dependent patients. A steady-state plasma concentration of methadone enantiomers, a measure of methadone metabolism, is an index of treatment response and efficacy of MMT. Although the methadone metabolism pathway has been partially revealed, no genome-wide pharmacogenomic study has been performed to identify genetic determinants and characterize genetic mechanisms for the plasma concentrations of methadone R- and S-enantiomers. This study was the first genome-wide pharmacogenomic study to identify genes associated with the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites in a methadone maintenance cohort. After data quality control was ensured, a dataset of 344 heroin-dependent patients in the Han Chinese population of Taiwan who underwent MMT was analyzed. Genome-wide single-locus and haplotype-based association tests were performed to analyze four quantitative traits: the plasma concentrations of methadone R- and S-enantiomers and their respective metabolites. A significant single nucleotide polymorphism (SNP), rs17180299 (raw p = 2.24 × 10(-8)), was identified, accounting for 9.541% of the variation in the plasma concentration of the methadone R-enantiomer. In addition, 17 haplotypes were identified on SPON1, GSG1L, and CYP450 genes associated with the plasma concentration of methadone S-enantiomer. These haplotypes accounted for approximately one-fourth of the variation of the overall S-methadone plasma concentration. The association between the S-methadone plasma concentration and CYP2B6, SPON1, and GSG1L were replicated in another independent study. A gene expression experiment revealed that CYP2B6, SPON1, and GSG1L can be activated concomitantly through a constitutive androstane receptor (CAR) activation pathway. In conclusion, this study revealed new genes associated with the plasma concentration of methadone, providing insight into the genetic foundation of methadone metabolism. The results can be applied to predict treatment responses and methadone-related deaths for individualized MMTs.

Metabolic labelling of cholesteryl glucosides in Helicobacter pylori reveals how the uptake of human lipids enhances bacterial virulence.

Helicobacter pylori infects approximately half of the human population and is the main cause of various gastric diseases. This pathogen is auxotrophic for cholesterol, which it converts upon uptake to various cholesteryl α-glucoside derivatives, including cholesteryl 6'-acyl and 6'-phosphatidyl α-glucosides (CAGs and CPGs). Owing to a lack of sensitive analytical methods, it is not known if CAGs and CPGs play distinct physiological roles or how the acyl chain component affects function. Herein we established a metabolite-labelling method for characterising these derivatives qualitatively and quantitatively with a femtomolar detection limit. The development generated an MS/MS database of CGds, allowing for profiling of all the cholesterol-derived metabolites. The subsequent analysis led to the unprecedented information that these bacteria acquire phospholipids from the membrane of epithelial cells for CAG biosynthesis. The resulting increase in longer or/and unsaturated CAG acyl chains helps to promote lipid raft formation and thus delivery of the virulence factor CagA into the host cell, supporting the idea that the host/pathogen interplay enhances bacterial virulence. These findings demonstrate an important connection between the chain length of CAGs and the bacterial pathogenicity.

Intraoperative neuromonitoring for removal of large vestibular schwannoma: Facial nerve outcome and predictive factors.

BACKGROUND: Preservation of facial nerve (FN) function is one of the major goals for resection of large vestibular schwannoma (VS) (≥ 30 mm). Little is known about the FN outcome and its predictive factors due to limited data. OBJECTIVE: To explore the predictive factors affecting FN outcome following resection of large VS. METHODS: 106 Large VS patients underwent surgical resection from 2010 to 2012 via intraoperative neuromonitoring for FN preservation approach. Postoperative FN function evaluation was conducted at the time points of 3-7th day, 3rd month and at the end of the 2nd year. Correlation between tumor size, intraoperative parameters and FN function were examined. RESULTS: The ratios of total and subtotal resection were 82.1% and 14.2%, respectively. Acceptable FN function was achieved in 78% patients. Patients with good FN function showed much smaller (P < 0.01) VS size than those of poor-FN function patients at 3-7th day, 3rd month and 2nd year. There was a significant correlation between facial motor evoked potential (FMEP) ratios and postoperative FN function at 3-7th day (r = -0.709, P < 0.001) 3rd month (r = -0.709, P< 0.001) and 2nd year (r = -0.750, P < 0.001). Maximal response amplitude (MRA) ratio was a supplementary indicator for train time in predicting both immediate and long-term FN function in patients with large VS. CONCLUSION: Indicative factors of both immediate and long-term postoperative FN function in large VSs include tumor size, intraoperative train time, start to final FMEP ratios and proximal to distal MRA ratios.

Assessment of CYP450 genetic variability effect on methadone dose and tolerance.

AIM: Methadone dose is related to treatment success in individuals under methadone maintenance treatment (MMT). We constructed a gene matrix using previously identified genetic polymorphisms in CYP450 and determined their genetic influence on methadone dose or tolerance. MATERIALS & METHODS: The allelic combinations of CYP450 genetic variants (two from CYP2C19, four from CYP2B6 and five from CYP3A4) were analyzed in 366 MMT heroin dependent patients as possible determinants of methadone dose and tolerance using analysis of covariance. RESULTS: Methadone dose (p = 0.007) and tolerance (p = 0.06) were mainly influenced by CYP2C19 gene dose. Moreover, dominant influence of the CYP2C19 gene dose on methadone dose and tolerance was only found among MMT patients with negative urine morphine test results, but not among those with positive results. CONCLUSION: The findings suggest that CYP2C19 gene dose may serve as a potential indicator for assessing methadone dose and tolerance in MMT patients.

Gene expression profiling of craniofacial fibrous dysplasia reveals ADAMTS2 overexpression as a potential marker.

Fibrous dysplasia (FD) as an abnormal bone growth is one of the common fibro-osseous leasions (FOL) in oral and maxillofacial region, however, its etiology still remains unclear. Here, we performed gene expression profiling of FD using microarray analysis to explore the key molecule events in FD development, and develop potential diagnostic markers or therapeutic targets for FD. We found that 1,881 genes exhibited differential expression with more than two-fold changes in FD compared to normal bone tissues, including 1,200 upregulated genes and 681 downregulated genes. Pathway analysis indicated that obviously activated pathways are Ribosome and ECM-receptor interaction pathways; downregulated pathways are "Hepatitis C" and "cancer" signaling pathways. We further validated the expression of ADAMTS2, one of most differentiated expressed genes, by Immunohistochemistry (IHC) in 40 of FD cases. Results showed that ADAMTS2 was significantly overexpressed in FD tissues, but rarely expressed in normal bone tissues, suggesting that ADAMTS2 could be a potential biomarker for FD. Thus, this study uncovered differentially expressed candidate genes in FD, which provides pilot data for understanding FD pathogenesis, and developing novel biomarkers for diagnosis and targeting of FD.

Functional genetic polymorphisms in CYP2C19 gene in relation to cardiac side effects and treatment dose in a methadone maintenance cohort.

Abstract Methadone maintenance therapy is an established treatment for heroin dependence. This study tested the influence of functional genetic polymorphisms in CYP2C19 gene encoding a CYP450 enzyme that contributes to methadone metabolism on treatment dose, plasma concentration, and side effects of methadone. Two single nucleotide polymorphisms (SNPs), rs4986893 (exon 4) and rs4244285 (exon 5), were selected and genotyped in 366 patients receiving methadone maintenance therapy in Taiwan. The steady-state plasma concentrations of both methadone and its EDDP metabolite enantiomers were measured. SNP rs4244285 allele was significantly associated with the corrected QT interval (QTc) change in the electrocardiogram (p=0.021), and the Treatment Emergent Symptom Scale (TESS) total score (p=0.021) in patients who continued using heroin, as demonstrated with a positive urine opiate test. Using the gene dose (GD) models where the CYP2C19 SNPs were clustered into poor (0 GD) versus intermediate (1 GD) and extensive (2 GD) metabolizers, we found that the extensive metabolizers required a higher dose of methadone (p=0.035), and showed a lower plasma R-methadone/methadone dose ratio (p=0.007) in urine opiate test negative patients, as well as a greater QTc change (p=0.008) and higher total scores of TESS (p=0.018) in urine opiate test positive patients, than poor metabolizers. These results in a large study sample from Taiwan suggest that the gene dose of CYP2C19 may potentially serve as an indicator for the plasma R-methadone/methadone dose ratio and cardiac side effect in patients receiving methadone maintenance therapy. Further studies of pharmacogenetic variation in methadone pharmacokinetics and pharmacodynamics are warranted in different world populations.

Hepatitis C virus infection influences the S-methadone metabolite plasma concentration.

BACKGROUND AND OBJECTIVES: Heroin-dependent patients typically contract hepatitis C virus (HCV) at a disproportionately high level due to needle exchange. The liver is the primary target organ of HCV infection and also the main organ responsible for drug metabolism. Methadone maintenance treatment (MMT) is a major treatment regimen for opioid dependence. HCV infection may affect methadone metabolism but this has rarely been studied. In our current study, we aimed to test the hypothesis that HCV may influence the methadone dosage and its plasma metabolite concentrations in a MMT cohort from Taiwan. METHODS: A total of 366 MMT patients were recruited. The levels of plasma hepatitis B virus (HBV), HCV, human immunodeficiency virus (HIV) antibodies (Ab), liver aspartate aminotransferase (AST) and alanine aminotransferase (ALT), as well as methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) were measured along with the urine morphine concentration and amphetamine screening. RESULTS: Of the 352 subjects in our cohort with HCV test records, 95% were found to be positive for plasma anti-HCV antibody. The liver functional parameters of AST (Wilcoxon Rank-Sum test, P = 0.02) and ALT (Wilcoxon Rank-Sum test, P = 0.04), the plasma methadone concentrations (Wilcoxon Rank-Sum test, P = 0.043) and the R-enantiomer of methadone concentrations (Wilcoxon Rank-Sum test, P = 0.032) were significantly higher in the HCV antibody-positive subjects than in the HCV antibody-negative patients, but not the S-EDDP/methadone dose ratio. The HCV levels correlated with the methadone dose (ß= 14.65 and 14.13; P = 0.029 and 0.03) and the S-EDDP/methadone dose ratio (ß= -0.41 and -0.40; P = 0.00084 and 0.002) in both univariate and multivariate regression analyses. CONCLUSIONS: We conclude that HCV may influence the methadone dose and plasma S-EDDP/methadone dose ratio in MMT patients in this preliminary study.

CYP1A2 genetic polymorphisms are associated with early antidepressant escitalopram metabolism and adverse reactions.

AIM: The liver CYP1A2 enzyme may metabolize antidepressant escitalopram (S-CIT) to S-desmethylcitalopram (S-DCIT) and S-didesmethylcitalopram (S-DDCIT). This study tested whether genetic polymorphisms in the CYP1A2 gene are associated with the treatment responses to S-CIT. MATERIALS & METHODS: Ten SNPs in CYP1A2 were selected and genotyped in 158 patients under S-CIT treatment. The serum levels of S-CIT and its metabolites were measured by HPLC. RESULTS: CYP1A2 SNPs rs2069521, rs2069526, rs4646425 and rs4646427 are significantly associated with the metabolic ratios of S-DDCIT/S-DCIT (p = 0.002, 0.018, 0.008 and 0.004, respectively) at week 2 of treatment. Carriers of the allele types associated with higher S-DDCIT/S-DCIT ratios had more severe side effects. CONCLUSION: These results suggest that genetic variants in CYP1A2 may be indicators for S-CIT metabolism and that the fast metabolizers may experience more severe adverse reactions in the early stages of S-CIT treatment. Original submitted 27 December 2012; Revision submitted 15 May 2013.