Fine-mapping the MHC locus in juvenile idiopathic arthritis (JIA) reveals genetic heterogeneity corresponding to distinct adult inflammatory arthritic diseases.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases, comprising seven categories. Genetic data could potentially be used to help redefine JIA categories and improve the current classification system. The human leucocyte antigen (HLA) region is strongly associated with JIA. Fine-mapping of the region was performed to look for similarities and differences in HLA associations between the JIA categories and define correspondences with adult inflammatory arthritides. METHODS: Dense genotype data from the HLA region, from the Immunochip array for 5043 JIA cases and 14 390 controls, were used to impute single-nucleotide polymorphisms, HLA classical alleles and amino acids. Bivariate analysis was performed to investigate genetic correlation between the JIA categories. Conditional analysis was used to identify additional effects within the region. Comparison of the findings with those in adult inflammatory arthritic diseases was performed. RESULTS: We identified category-specific associations and have demonstrated for the first time that rheumatoid factor (RF)-negative polyarticular JIA and oligoarticular JIA are genetically similar in their HLA associations. We also observe that each JIA category potentially has an adult counterpart. The RF-positive polyarthritis association at HLA-DRB1 amino acid at position 13 mirrors the association in adult seropositive rheumatoid arthritis (RA). Interestingly, the combined oligoarthritis and RF-negative polyarthritis dataset shares the same association with adult seronegative RA. CONCLUSIONS: The findings suggest the value of using genetic data in helping to classify the categories of this heterogeneous disease. Mapping JIA categories to adult counterparts could enable shared knowledge of disease pathogenesis and aetiology and facilitate transition from paediatric to adult services.

The association of PTPN22 rs2476601 with juvenile idiopathic arthritis is specific to females.

A preponderance of females develop autoimmune disease, including juvenile idiopathic arthritis (JIA), yet the reason for this bias remains elusive. Evidence suggests that genetic risk of disease may be influenced by sex. PTPN22 rs2476601 is associated with JIA and numerous other autoimmune diseases, and has been reported to show female-specific association with type 1 diabetes. We performed main effect and sex-stratified association analyses to determine whether a sex-specific association exists in JIA. As expected, rs2476601 was associated with JIA in our discovery (413 cases and 690 controls) and replication (1008 cases and 9284 controls) samples. Discovery sample sex-stratified analyses demonstrated an association specifically in females (odds ratio (OR)=2.35, 95% confidence interval (CI)=1.52-3.63, P=0.00011) but not males (OR=0.91, 95% CI=0.52-1.60, P=0.75). This was similarly observed in the replication sample. There was evidence for genotype-by-sex interaction (Pinteraction=0.009). The association between rs2476601 and JIA appears restricted to females, partly accounting for the predominance of females with this disease.

Possible drug-drug interaction between high-dose esomeprazole and phenprocoumon.

PURPOSE: It is established that omeprazole increases (R)+ warfarin levels with around 10 %. Whether (es)omeprazole also increase the plasma levels of acenocoumarol or phenprocoumon is still uncertain. We analyzed whether addition of (es)omeprazole to acenocoumarol or phenprocoumon increases the international normalized ratio (INR) levels and the risk of overanticoagulation. METHODS: We analyzed all hospital admissions in four teaching hospitals. Patients who used coumarins and pantoprazole or (es)omeprazole simultaneously for at least four consecutive days were included in the study. We analyzed the highest INR level and whether patients had an INR level above six. We compared patients using omeprazole or esomeprazole with patients using pantoprazole, because for pantoprazole, no interaction has been reported. RESULTS: We analyzed 5747 admissions with 4540 patients using one of the drug combinations. For acenocoumarol (4578 admissions), no significant differences were found between users of esomeprazole, omeprazole, and pantoprazole. For phenprocoumon (1169 admissions), the highest INR measured was significantly higher in users of esomeprazole than in users of pantoprazole (4.7 versus 4.3; p = 0.035). No significant difference was found with omeprazole versus pantoprazole (4.3 versus 4.3; p = 0.66). A non-significant association was found between the esomeprazole dose and the highest INR level (p = 0.055). The risk of an INR above six did not differ significantly between esomeprazole and pantoprazole (27.7 % versus 22.9 %; p = 0.34). CONCLUSIONS: The use of esomeprazole simultaneously with phenprocoumon during hospital admissions might increase the anticoagulant effect. The clinical relevance seems to be limited, because no statistically significant increased risk of overanticoagulation was found.

Genetic variation in the ABCC2 gene is associated with dose decreases or switches to other cholesterol-lowering drugs during simvastatin and atorvastatin therapy.

Several statins are substrates for the multidrug resistance-associated protein 2 transporter, encoded by the ABCC2 gene. We analyzed in the Rotterdam Study whether the common polymorphisms -24C>T, 1249G>A and 3972C>T in the ABCC2 gene were associated with a dose decrease or switch to another cholesterol-lowering drug in simvastatin and atorvastatin users. These events could indicate an adverse effect or a too strong reduction in cholesterol level. We identified 1014 simvastatin and atorvastatin users during the period 1 January 1991 to 1 January 2010. Associations between genetic variation and the risk of these events were analyzed using Cox proportional hazards modelling. The ABCC2 -24C>T genotype (HR 1.32 95% CI 1.04-1.69) and the H12 haplotype versus the H2 haplotype (HR 1.49; 95% CI 1.06-2.09) were associated with these events in simvastatin users. A similar but not significant association was found in atorvastatin users. To conclude, genetic variation in the ABCC2 gene is associated with these events in simvastatin users.

A gene variant near ATM is significantly associated with metformin treatment response in type 2 diabetes: a replication and meta-analysis of five cohorts.

AIMS/HYPOTHESIS: In this study we aimed to replicate the previously reported association between the glycaemic response to metformin and the SNP rs11212617 at a locus that includes the ataxia telangiectasia mutated (ATM) gene in multiple additional populations. METHODS: Incident users of metformin selected from the Diabetes Care System West-Friesland (DCS, n = 929) and the Rotterdam Study (n = 182) from the Netherlands, and the CARDS Trial (n = 254) from the UK were genotyped for rs11212617 and tested for an association with both HbA(1c) reduction and treatment success, defined as the ability to reach the treatment target of an HbA(1c) ≤ 7 % (53 mmol/mol). Finally, a meta-analysis including data from literature was performed. RESULTS: In the DCS cohort, we observed an association between rs11212617 genotype and treatment success on metformin (OR 1.27, 95% CI 1.03, 1.58, p = 0.028); in the smaller Rotterdam Study cohort, a numerically similar but non-significant trend was observed (OR 1.45, 95% CI 0.87, 2.39, p = 0.15); while in the CARDS cohort there was no significant association. In meta-analyses of these three cohorts separately or combined with the previously published cohorts, rs11212617 genotype is associated with metformin treatment success (OR 1.24, 95% CI 1.04, 1.49, p = 0.016 and OR 1.25, 95% CI 1.33, 1.38, p = 7.8 × 10(-6), respectively). CONCLUSIONS/INTERPRETATION: A gene variant near ATM is significantly associated with metformin treatment response in type 2 diabetic patients from the Netherlands and the UK. This is the first robustly replicated common susceptibility locus found to be associated with metformin treatment response.

Genetic variation in the organic cation transporter 1 is associated with metformin response in patients with diabetes mellitus.

The organic cation transporter 1, encoded by the SLC22A1 gene, is responsible for the uptake of the anti-hyperglycaemic drug, metformin, in the hepatocyte. We assessed whether a genetic variation in the SLC22A1 gene is associated with the glucose-lowering effect of metformin. Incident metformin users in the Rotterdam Study, whose HbA1c measurements were available, were identified. Associations between 11 tagging single nucleotide polymorphisms in the SLC22A1 gene and change in the HbA1c level were analyzed. A total of 102 incident metformin users were included in this study sample. Except for the rs622342 A>C polymorphism, no significant differences in metformin response were observed. For each minor C allele at rs622342, the reduction in HbA1c levels was 0.28% less (95% CI 0.09-0.47, P=0.005). After Bonferroni correction, the P-value was 0.050. To conclude, genetic variation at rs622342 in the SLC22A1 gene was associated with the glucose-lowering effect of metformin in patients with diabetes mellitus.

[Loss of kidney function caused by implanted gentamicin sponges]. / Nierfunctieverlies door gentamicine-implantatiesponzen.

BACKGROUND: Infected joint replacements can be treated with gentamicin-containing materials for implantation. This may lead to side effects, especially in patients with impaired renal function. CASE DESCRIPTION: A 74-year-old woman underwent two surgeries for an acutely infected hip replacement. Gentamicin sponges (Garacol) were implanted during both interventions. The day after the second operation, her serum gentamicin levels had risen to toxic values. This confirmed the suspicion that she had a kidney impairment which was probably caused by the implanted gentamicin-containing sponges. In order to limit kidney damage, the patient received continuous venovenous haemodiafiltration (CVVHD). Outpatient check-up 3 months later found that the creatinine levels in the serum of the patient had normalised. CONCLUSION: Locally administered gentamicin sponges for implantation can cause therapeutic serum levels leading to systemic side effects. It is advisable to check kidney function before using the sponges. If this is reduced, it is recommended to be cautious when using these sponges for implantation. In case of toxic elevated values, CVVHD can limit kidney damage - which is reversible, given time - by accelerating gentamicin excretion.

Molecular species of plasminogen activators secreted by normal and neoplastic human cells.

A survey of 56 normal and neoplastic tissues has shown that plasminogen activators were released by cultured human cells in several molecular weights and their susceptibility to inhibition by antibodies to the normal urinary enzyme, urokinase. Melanoma cells characteristically secreted plasminogen activators which were immunochemically distinct from urokinase and which migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a prominent, closely spaced doublet with an apparent molecular weight of approximately 70,000 and a minor molecular weight component of approximately 60,000. Enzymes with similar characteristics have been observed in serum-free harvest fluids collected from other neoplastic tissue (a breast carcinoma, a glioblastoma, a malignant teratoma, a uterine sarcoma, and a carcinoma of the renal pelvis) and from normal tissue (8-week embryo fibroblasts, normal esophageal fibroblasts, and one culture of normal adult bladder epithelium). Plasminogen activators released by cells derived from most normal adult tissues, or from a 26-week-old embryo, and from other tumors of ectodermal or mesenchymal origin were inhibited by anti-urokinase antibody and showed a closely spaced doublet with a molecular weight of 60,000 as the most abundant molecular species with no evidence of the enzyme with a molecular weight of 70,000.

Nicotinamide Phosphoribosyltransferase Attenuates Methotrexate Response in Juvenile Idiopathic Arthritis and In Vitro.

Variability in response to methotrexate (MTX) in the treatment of juvenile idiopathic arthritis (JIA) remains unpredictable and poorly understood. Based on previous studies implicating an interaction between nicotinamide phosphoribosyltransferase (NAMPT) expression and MTX therapy in inflammatory arthritis, we hypothesized that increased NAMPT expression would be associated with reduced therapeutic response to MTX in patients with JIA. A significant association was found between increased plasma concentrations of NAMPT and reduced therapeutic response in patients with JIA treated with MTX. Inhibition of NAMPT in cell culture by either siRNA-based gene silencing or pharmacological inhibition with FK-866 was found to result in a fourfold increase in the pharmacological activity of MTX. Collectively, these findings provide evidence that NAMPT inhibits the pharmacological activity of MTX and may represent a predictive biomarker of response, as well as a therapeutic target, in the treatment of JIA with MTX.

Multidrug and toxin extrusion 1 and human organic cation transporter 1 polymorphisms in patients with castration-resistant prostate cancer receiving metformin (SAKK 08/09).

BACKGROUND: This study was initiated to explore the impact of organic cation transporter 1 (OCT1) and multidrug and toxin extrusion transporter 1 (MATE1) genetic polymorphisms on toxicity, and clinical activity of metformin in patients with castration-resistant prostate cancer (CRPC). METHODS: The SAKK 08/09 trial included 44 patients with CRPC to receive single-agent metformin 1000 mg two times a day until disease progression or unwanted toxicity. Drug pathway-associated gene polymorphisms of OCT1 (rs622342) and MATE1 (rs2289669) were assessed. The primary objective of this study was to define the relationship between mutations in OCT1, MATE1 and progression-free survival (PFS) at 12 weeks absolute PFS and PSA response in consenting patients of SAKK 08/09. The secondary objective of this study was to analyze the association between mutations in OCT1, MATE1, metformin-related toxicity, PSA response at 12 weeks and overall survival. RESULTS: Thirty-six patients were evaluable for pharmacogenetic analysis. Homozygous carriers of the polymorphic OCT1 C-allele had no metformin-related toxicity as compared with 41.9% for any metformin-related toxicity in carriers of at least one wild-type A-allele (P=0.07). Disease progression according to RECIST (Response Evaluation Criteria In Solid Tumors) was significantly more frequent in homozygous carriers of the polymorphic OCT1 C-allele (80%) as compared with carriers of at least one wild-type A-allele (28.6%) (P=0.002). Disease progression according to RECIST was also more frequent in carriers of at least one polymorphic MATE1 A-allele (44%) as compared with homozygous carriers of the wild-type G-allele (12.5%) (P=0.07). OCT1 and MATE1 were not associated with PFS. CONCLUSIONS: The polymorphic OCT1 C-allele has been shown to be associated with less metformin-related toxicity and a higher risk of tumor progression in patients with CRPC receiving metformin as an anticancer treatment. Polymorphisms in metformin drug transporters are attractive molecular markers to serve as potential predictors of efficacy in future clinical studies.

HIV-1 strains from India are highly divergent from prototypic African and US/European strains, but are linked to a South African isolate.

OBJECTIVE: To gain molecular insights into different HIV-1 strains present in two different states of India, nucleotide sequences derived from the env region of four HIV-1 strains were analysed. DESIGN: HIV-1 was isolated from high-risk patients from the states of Maharashtra (city of Bombay) and Goa. The molecular analysis of the env region encompassed all variable domains of the external glycoprotein, gp120. METHODS: Genomic DNA from cultured cells infected with each of the four Indian HIV-1 strains independently was amplified by polymerase chain reaction (PCR). PCR fragments were cloned and sequenced and a phylogenetic tree constructed. RESULTS: All four Indian HIV-1 sequences were closely related to each other. The closest related sequence to them was from a South African isolate, HIV-1NOF, with a homology of 85-87%. In the phylogenetic tree, the Indian and the South African HIV-1 sequences cluster together and constitute a subtype different from the North American/European, Central African, Uganda/Rwanda and Northern Thailand subtypes. Interestingly, the viruses of this subtype are characterized by an additional potential N-glycosylation site C-terminal to the CD4-binding domain. CONCLUSION: The low variation between the HIV-1 sequences from randomly chosen individuals from high-risk cohorts in two Indian states suggests a rapid and recent spread of HIV and, possibly, introduction of the virus by the same route, most probably heterosexual transmission. The rapid spread of HIV-1 variants in India, which form a subgroup of their own together with a South African strain, necessitate consideration of these strains in vaccine development.

The utility of the non-human primate; model for studying gene by environment interactions in behavioral research.

Variation in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) has been associated with anxiety and harm avoidance and is weakly associated with a number of neuropsychiatric disorders, including Type II alcoholism, which has a high rate of comorbidity with antisocial personality disorder. Studies have also demonstrated interactions between 5-HTLPR variation and environmental stress on the incidence of depression. As in humans, there is a serotonin transporter gene promoter length polymorphism in rhesus macaques that produces similar decreases in transcriptional efficiency. Macaques with histories of early-life stress have been shown to exhibit impulsive aggression, incompetent social behavior and increased behavioral and endocrine responsivity to stress. In this paper, we review studies performed previously in our lab and present preliminary data examining interactions between early rearing and serotonin transporter gene promoter variation on the incidences of play behavior and aggression in infant rhesus macaques. The data presented here highlight the importance of considering gene-environment interactions when studying childhood risk factors for aggression, anxiety and related neuropsychiatric disorders and support the use of the nonhuman primate for studing gene by environment interactions in behavioral research.

Analysis of partial gag and env gene sequences of HIV type 1 strains from southern Africa.

PIP: HIV-1 is spreading at an exponential rate in southern Africa, with a current doubling time of approximately one year. An estimated 2 million of South Africa's 36 million population are already infected with HIV. Information on the extent of variability of HIV-1 sequences in the region is important for the development of vaccines, the evaluation of new therapies, and for structure/function studies of the viral genome and proteins. The authors isolated and partially sequenced local strains of the virus. The first strain sequenced was determined to be a new subtype of HIV-1, designated subtype C(2). HIV-1 subtypes B and D are also circulating within southern Africa. The derived phylogenetic trees for the various strains are presented. It is possible that southern African HIV-1 strains have evolved from Central African ones during their spread southward over time and geographic distance. The data on HIV-1 env and gag gene variability presented in this paper have implications for the design of vaccines intended for use in southern Africa and India. The results also establish new limits of variability for the virus, by extending the phylogenetic tree along a new branch.^ieng

Optimization of pediatric rheumatology therapeutics.

Therapeutics used in pediatric rheumatology have evolved substantially over the past few decades; they currently target specific cytokines that are known to be involved in the pathophysiology of these complex diseases. The field is limited by a lack of full understanding of the etiology and pathophysiology of these conditions, as well as by the rarity of these diseases in the pediatric population. Advances in biomarkers, pharmacogenomics, and biologic therapies, along with a more unified effort from clinicians and investigators, have enabled continued growth in the field, fostering the hope for the most effective and appropriate therapeutics for pediatric patients.

Rates and determinants of HIV-attributable mortality among rural female sex workers in Northern Karnataka, India.

Female sex workers (FSWs) have among the highest rates of HIV infection in India. However, little is known about their HIV-specific mortality rates. In total, 1561 FSWs participated in a cohort study in Karnataka. Outcome data (mortality) were available on 1559 women after 15 months of follow-up. To gather details on deaths, verbal autopsy (VA) questionnaires were administered to key informants. Two physicians reviewed the VA reports and assigned underlying causes of death. Forty-seven deaths were reported during the follow-up (overall mortality rate was 2.44 per 100 person-years), with VA data available on 45 women. Thirty-five (75.6%) of these women were known to be HIV-positive, but only 42.5% were on antiretroviral therapy (ART). Forty deaths were assessed to be HIV-related, for an HIV-attributable mortality rate of 2.11 deaths per 100 person-years. Absence of a current regular partner (incidence rate ratio: 2.79; 95% confidence interval [CI]: 1.39-5.60) and older age (1.06; 1.01-1.11) were associated with increased HIV-attributable mortality. Reported duration in sex work was not related to HIV-attributable mortality. We found a high HIV-related mortality rate among this cohort of FSWs; nearly 10 times that of national mortality rates among women of a similar age group. Older age, but not reported duration in sex work, was associated with increased mortality, and suggests HIV acquisition prior to self-reported initiation into sex work. Despite significant efforts, there remain considerable gaps in HIV prevention near or before entry into sex work, as well as access and uptake of HIV treatment among FSWs.

Improved methods and standards for telomerase detection: quantitative histopathology using antibody staining.

Evaluation of telomerase as an early detection biomarker for cancer has been hindered by a lack of reliable methods and standards for in situ histochemical measurement. Improved histochemical methods for measuring telomerase could expedite the acceptance of telomerase as a biomarker for use in diagnostic and clinical applications. The lack of a crystal structure for telomerase coupled with high variability in the antibodies available for immunohistochemical analysis has led to confusion in the literature regarding the binding specificity of these antibodies. We have developed an automated fluorescence microscopy protocol to assess the specificity of three fluorescently labeled telomerase antibodies and to quantify telomerase in cultured human tumor cells and in human fibroblast cells as a control. Significant differences in staining intensity and distribution were observed. Fluorescence measurements in these cell lines were compared to telomerase measured by the telomerase repeat amplification protocol, reverse transcription-polymerase chain reaction, and flow cytometry. This combination of measurements ensured a more complete quantitation of telomerase levels in each of the cell lines and could also be used as a model for validation of other biomarkers for clinical use.