Pharmacogenetics of OATP Transporters Reveals That SLCO1B1 c.388A>G Variant Is Determinant of Increased Atorvastatin Response

Aims: The relationship between variants in SLCO1B1 and SLCO2B1 genes and lipid-lowering response to atorvastatin was investigated. Material and Methods: One-hundred-thirty-six unrelated individuals with hypercholesterolemia were selected and treated with atorvastatin (10 mg/day/4 weeks). They were genotyped with a panel of ancestry informative markers for individual African component of ancestry (ACA) estimation by SNaPshot® and SLCO1B1 (c.388A>G, c.463C>A and c.521T>C) and SLCO2B1 (−71T>C) gene polymorphisms were identified by TaqMan® Real-time PCR. Results: Subjects carrying SLCO1B1 c.388GG genotype exhibited significantly high low-density lipoprotein (LDL) cholesterol reduction relative to c.388AA+c.388AG carriers (41 vs. 37%, p = 0.034). Haplotype analysis revealed that homozygous of SLCO1B1*15 (c.521C and c.388G) variant had similar response to statin relative to heterozygous and non-carriers. A multivariate logistic regression analysis confirmed that c.388GG genotype was associated with higher LDL cholesterol reduction in the study population (OR: 3.2, CI95%:1.3–8.0, p < 0.05). Conclusion: SLCO1B1 c.388A>G polymorphism causes significant increase in atorvastatin response and may be an important marker for predicting efficacy of lipid-lowering therapy

Infliximab Trough Levels Are Not Predictive of Relapse in Patients with IBD in Endoscopic Remission: A Multicenter Cohort Study

Background: Therapeutic drug monitoring (TDM) is important in optimizing use of biologics in inflammatory bowel diseases (IBD). However, the role of proactive TDM during remission remains uncertain. Methods: This retrospective study included patients receiving infliximab (IFX) therapy at Massachusetts General Hospital or Erasmus University Medical Center. All eligible patients had completed induction phase of IFX and were in clinical and endoscopic remission. Our primary outcome was clinical relapse within 2 years after baseline. Multivariable regression models examined the association between infliximab trough levels during remission and relapse, need for IBD-related surgery or hospitalization. Results: Our study cohort included 110 patients with IBD (72 CD, 38 UC) on IFX maintenance therapy. In total, 12 patients (10.9%) experienced relapse of disease over 2 years. The mean IFX trough level at baseline was 8.0 µg/mL (± 8.6) and did not differ between the institutions. 49.1% of patients had levels < 5 µg/mL and 2.7% had antibodies to infliximab at baseline. There was no difference in the mean IFX trough levels between patients who relapsed (7.5 µg/mL ± 3.7 µg/mL) over 24 months compared to those who did not (8.1 µg/mL ± 7.9 µg/mL, p = 0.815). On multivariable logistic regression analysis, IFX trough levels at baseline were not associated with relapse of disease over 24 months (OR 1.01, 95% CI 0.93–1.09, p = 0.856). Conclusion: This retrospective multicenter study provides evidence that IFX trough levels during quiescent disease do not predict relapse over 2 years, suggestive that proactive TDM in this setting is not warranted

Cerebrospinal fluid kappa free light chains for the diagnosis of multiple sclerosis: A consensus statement

Cerebrospinal fluid (CSF) analysis is of utmost importance for diagnosis and differential diagnosis of patients with suspected multiple sclerosis (MS). Evidence of intrathecal immunoglobulin G (IgG) synthesis proves the inflammatory nature of the disease, increases diagnostic certainty and substitutes for dissemination in time according to current diagnostic criteria. The gold standard to determine intrathecal IgG synthesis is the detection of CSF-restricted oligoclonal bands (OCBs). However, advances in laboratory methods brought up κ-free light chains (FLCs) as a new biomarker, which are produced in excess over intact immunoglobulins and accumulate in CSF in the case of central nervous system-derived inflammation. Overwhelming evidence showed a high diagnostic accuracy of intrathecal κ-FLC synthesis in MS with sensitivity and specificity of approximately 90% similar to OCB. κ-FLCs have advantages as its detection is fast, easy, cost-effective, reliable, rater-independent and returning quantitative results which might also improve the value of predicting MS disease activity. An international panel of experts in MS and CSF diagnostics developed a consensus of all participants. Six recommendations are given for establishing standard CSF evaluation in patients suspected of having MS. The panel recommended to include intrathecal κ-FLC synthesis in the next revision of MS diagnostic criteria as an additional tool to measure intrathecal immunoglobulin synthesis

CYP3A5*3A allele is associated with reduced lowering-lipid response to atorvastatin in individuals with hypercholesterolemia

Background: The cytochrome P450 isoenzyme 3A5 (CYP3A5) has an important role on biotransformation of xenobiotics. CYP3A5 SNPs have been associated with variations on enzyme activity that can modify the metabolism of several drugs. Methods: In order to evaluate the influence of CYP3A5 variants on response to lowering-cholesterol drugs, 139 individuals with hypercholesterolemia were selected. After a wash-out period of 4 weeks, individuals were treated with atorvastatin (10 mg/day/4 weeks). Genomic DNA was extracted by a salting-out procedure. CYP3A5*3C, CYP3A5*6 and CYP3A5*1D were analyzed by PCR-RFLP and DNA sequencing. Results: >Frequencies of the CYP3A5*3C and CYP3A5*1D alleles were lower in individuals of African descent (*3C: 47.8% and *1D: 55.2%) than in non-Africans (*3C: 84.9% and *1D 84.8%, p<0.01). Non-Africans carrying *3A allele (*3C and *1D combined alleles) had lower total and LDL-cholesterol response to atorvastatin than non-*3A allele carriers (p<0.05). Conclusion: CYP3A5*3A allele is associated with reduced cholesterol-lowering response to atorvastatin in non-African individuals. (C) 2008 Elsevier B.V. All rights reserved.FAPESP[2000/12224-0]FAPESP[2003/02086-8]CNPq, Brasilia, DF, Brazi