Leveraging electronic health records to study pleiotropic effects on bipolar disorder and medical comorbidities.

Patients with bipolar disorder (BD) have a high prevalence of comorbid medical illness. However, the mechanisms underlying these comorbidities with BD are not well known. Certain genetic variants may have pleiotropic effects, increasing the risk of BD and other medical illnesses simultaneously. In this study, we evaluated the association of BD-susceptibility genetic variants with various medical conditions that tend to co-exist with BD, using electronic health records (EHR) data linked to genome-wide single-nucleotide polymorphism (SNP) data. Data from 7316 Caucasian subjects were used to test the association of 19 EHR-derived phenotypes with 34 SNPs that were previously reported to be associated with BD. After Bonferroni multiple testing correction, P<7.7 × 10(-5) was considered statistically significant. The top association findings suggested that the BD risk alleles at SNP rs4765913 in CACNA1C gene and rs7042161 in SVEP1 may be associated with increased risk of 'cardiac dysrhythmias' (odds ratio (OR)=1.1, P=3.4 × 10(-3)) and 'essential hypertension' (OR=1.1, P=3.5 × 10(-3)), respectively. Although these associations are not statistically significant after multiple testing correction, both genes have been previously implicated with cardiovascular phenotypes. Moreover, we present additional evidence supporting these associations, particularly the association of the SVEP1 SNP with hypertension. This study shows the potential for EHR-based analyses of large cohorts to discover pleiotropic effects contributing to complex psychiatric traits and commonly co-occurring medical conditions.

TSPAN5, ERICH3 and selective serotonin reuptake inhibitors in major depressive disorder: pharmacometabolomics-informed pharmacogenomics.

Millions of patients suffer from major depressive disorder (MDD), but many do not respond to selective serotonin reuptake inhibitor (SSRI) therapy. We used a pharmacometabolomics-informed pharmacogenomics research strategy to identify genes associated with metabolites that were related to SSRI response. Specifically, 306 MDD patients were treated with citalopram or escitalopram and blood was drawn at baseline, 4 and 8 weeks for blood drug levels, genome-wide single nucleotide polymorphism (SNP) genotyping and metabolomic analyses. SSRI treatment decreased plasma serotonin concentrations (P<0.0001). Baseline and plasma serotonin concentration changes were associated with clinical outcomes (P<0.05). Therefore, baseline and serotonin concentration changes were used as phenotypes for genome-wide association studies (GWAS). GWAS for baseline plasma serotonin concentrations revealed a genome-wide significant (P=7.84E-09) SNP cluster on chromosome four 5' of TSPAN5 and a cluster across ERICH3 on chromosome one (P=9.28E-08) that were also observed during GWAS for change in serotonin at 4 (P=5.6E-08 and P=7.54E-07, respectively) and 8 weeks (P=1.25E-06 and P=3.99E-07, respectively). The SNPs on chromosome four were expression quantitative trait loci for TSPAN5. Knockdown (KD) and overexpression (OE) of TSPAN5 in a neuroblastoma cell line significantly altered the expression of serotonin pathway genes (TPH1, TPH2, DDC and MAOA). Chromosome one SNPs included two ERICH3 nonsynonymous SNPs that resulted in accelerated proteasome-mediated degradation. In addition, ERICH3 and TSPAN5 KD and OE altered media serotonin concentrations. Application of a pharmacometabolomics-informed pharmacogenomic research strategy, followed by functional validation, indicated that TSPAN5 and ERICH3 are associated with plasma serotonin concentrations and may have a role in SSRI treatment outcomes.

Feasibility of investigating differential proteomic expression in depression: implications for biomarker development in mood disorders.

The objective of this study was to determine whether proteomic profiling in serum samples can be utilized in identifying and differentiating mood disorders. A consecutive sample of patients with a confirmed diagnosis of unipolar (UP n=52) or bipolar depression (BP-I n=46, BP-II n=49) and controls (n=141) were recruited. A 7.5-ml blood sample was drawn for proteomic multiplex profiling of 320 proteins utilizing the Myriad RBM Discovery Multi-Analyte Profiling platform. After correcting for multiple testing and adjusting for covariates, growth differentiation factor 15 (GDF-15), hemopexin (HPX), hepsin (HPN), matrix metalloproteinase-7 (MMP-7), retinol-binding protein 4 (RBP-4) and transthyretin (TTR) all showed statistically significant differences among groups. In a series of three post hoc analyses correcting for multiple testing, MMP-7 was significantly different in mood disorder (BP-I+BP-II+UP) vs controls, MMP-7, GDF-15, HPN were significantly different in bipolar cases (BP-I+BP-II) vs controls, and GDF-15, HPX, HPN, RBP-4 and TTR proteins were all significantly different in BP-I vs controls. Good diagnostic accuracy (ROC-AUC⩾0.8) was obtained most notably for GDF-15, RBP-4 and TTR when comparing BP-I vs controls. While based on a small sample not adjusted for medication state, this discovery sample with a conservative method of correction suggests feasibility in using proteomic panels to assist in identifying and distinguishing mood disorders, in particular bipolar I disorder. Replication studies for confirmation, consideration of state vs trait serial assays to delineate proteomic expression of bipolar depression vs previous mania, and utility studies to assess proteomic expression profiling as an advanced decision making tool or companion diagnostic are encouraged.

Genetic markers associated with abstinence length in alcohol-dependent subjects treated with acamprosate.

Acamprosate supports abstinence in some alcohol-dependent subjects, yet predictors of response are unknown. To identify response biomarkers, we investigated associations of abstinence length with polymorphisms in candidate genes in glycine and glutamate neurotransmission pathways and genes previously implicated in acamprosate response. Association analyses were conducted in the discovery sample of 225 alcohol-dependent subjects treated with acamprosate for 3 months in community-based treatment programs in the United States. Data from 110 alcohol-dependent males treated with acamprosate in the study PREDICT were used for replication of the top association findings. Statistical models were adjusted for relevant covariates, including recruitment site and baseline clinical variables associated with response. In the discovery sample, shorter abstinence was associated with increased intensity of alcohol craving and lower number of days between the last drink and initiation of acamprosate treatment. After adjustment for covariates, length of abstinence was associated with the GRIN2B rs2058878 (P=4.6 × 10(-5)). In the replication sample, shorter abstinence was associated with increased craving, increased depressive mood score and higher alcohol consumption. Association of abstinence length with GRIN2B rs2058878 was marginally significant (P=0.0675); as in the discovery sample, the minor A allele was associated with longer abstinence. Furthermore, rs2300272, which is in strong linkage disequilibrium with rs2058878, was also associated with abstinence length (P=0.049). This is the first report of a replicated association of genetic markers with the length of abstinence in acamprosate-treated alcoholics. Investigation of the underlying mechanisms of this association and its usefulness for individualized treatment selection should follow.

Inflammation-related genetic variants predict toxicity following definitive radiotherapy for lung cancer.

Definitive radiotherapy improves locoregional control and survival in inoperable non-small cell lung cancer patients. However, radiation-induced toxicities (pneumonitis/esophagitis) are common dose-limiting inflammatory conditions. We therefore conducted a pathway-based analysis to identify inflammation-related single-nucleotide polymorphisms associated with radiation-induced pneumonitis or esophagitis. A total of 11,930 single-nucleotide polymorphisms were genotyped in 201 stage I-III non-small cell lung cancer patients treated with definitive radiotherapy. Validation was performed in an additional 220 non-small cell lung cancer cases. After validation, 19 single-nucleotide polymorphisms remained significant. A polygenic risk score was generated to summarize the effect from validated single-nucleotide polymorphisms. Significant improvements in discriminative ability were observed when the polygenic risk score was added into the clinical/epidemiological variable-based model. We then used 277 lymphoblastoid cell lines to assess radiation sensitivity and expression quantitative trait loci (eQTL) relationships of the identified single-nucleotide polymorphisms. Three genes (PRKCE, DDX58, and TNFSF7) were associated with radiation sensitivity. We concluded that inflammation-related genetic variants could contribute to the development of radiation-induced toxicities.

Pharmacogenomics of selective serotonin reuptake inhibitor treatment for major depressive disorder: genome-wide associations and functional genomics.

A genome-wide association (GWA) study of treatment outcomes (response and remission) of selective serotonin reuptake inhibitors (SSRIs) was conducted using 529 subjects with major depressive disorder. While no SNP associations reached the genome-wide level of significance, 14 SNPs of interest were identified for functional analysis. The rs11144870 SNP in the riboflavin kinase (RFK) gene on chromosome 9 was associated with 8-week treatment response (odds ratio (OR)=0.42, P=1.04 × 10⁻6). The rs915120 SNP in the G protein-coupled receptor kinase 5 (GRK5) gene on chromosome 10 was associated with 8-week remission (OR=0.50, P=1.15 × 10⁻5). Both SNPs were shown to influence transcription by a reporter gene assay and to alter nuclear protein binding using an electrophoretic mobility shift assay. This report represents an example of joining functional genomics with traditional GWA study results derived from a GWA analysis of SSRI treatment outcomes. The goal of this analytical strategy is to provide insights into the potential relevance of biologically plausible observed associations.

Multivariate models to detect genomic signatures for a class of drugs: application to thiopurines pharmacogenomics.

Often, analysis for pharmacogenomic studies involving multiple drugs from the same class is completed by analyzing each drug individually for association with genomic variation. However, by completing the analysis of each drug individually, we may be losing valuable information. When studying multiple drugs from the same drug class, one may wish to determine genomic variation that explains the difference in response between individuals for the drug class, as opposed to each individual drug. Therefore, we have developed a multivariate model to assess whether genomic variation impacts a class of drugs. In addition to determine genomic effects that are similar for the drugs, we will also be able to determine genomic effects that differ between the drugs (that is, interaction). We will illustrate the utility of this multivariate model for cytotoxicity and genomic data collected on the Coriell Human Variation Panel for the class of anti-purine metabolites (6-mercaptopurine and 6-thioguanine).

Glycine and a glycine dehydrogenase (GLDC) SNP as citalopram/escitalopram response biomarkers in depression: pharmacometabolomics-informed pharmacogenomics.

Major depressive disorder (MDD) is a common psychiatric disease. Selective serotonin reuptake inhibitors (SSRIs) are an important class of drugs used in the treatment of MDD. However, many patients do not respond adequately to SSRI therapy. We used a pharmacometabolomics-informed pharmacogenomic research strategy to identify citalopram/escitalopram treatment outcome biomarkers. Metabolomic assay of plasma samples from 20 escitalopram remitters and 20 nonremitters showed that glycine was negatively associated with treatment outcome (P = 0.0054). This observation was pursued by genotyping tag single-nucleotide polymorphisms (SNPs) for genes encoding glycine synthesis and degradation enzymes, using 529 DNA samples from SSRI-treated MDD patients. The rs10975641 SNP in the glycine dehydrogenase (GLDC) gene was associated with treatment outcome phenotypes. Genotyping for rs10975641 was carried out in 1,245 MDD patients in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, and its presence was significant (P = 0.02) in DNA taken from these patients. These results highlight a possible role for glycine in SSRI response and illustrate the use of pharmacometabolomics to "inform" pharmacogenomics.

Empyema and bronchopleural fistula after pneumonectomy: factors affecting incidence.

BACKGROUND: Factors affecting the incidence of empyema and bronchopleural fistula (BPF) after pneumonectomy were analyzed. METHODS: All patients who underwent pneumonectomy at the Mayo Clinic in Rochester, Minnesota, from January 1985 to September 1998 were reviewed. There were 713 patients (514 males and 199 females). Ages ranged from 12 to 86 years (median 64 years). Indication for resection was primary malignancy in 607 patients (85.1%), metastatic disease in 32 (4.5%), and benign disease in 74 (10.4%). One hundred fifteen patients (16.1%) underwent completion pneumonectomy. Factors affecting the incidence of postoperative empyema and BPF were analyzed using univariate and multivariate analysis. RESULTS: Empyema was documented in 53 patients (7.5%; 95% confidence interval [CI], 5.7% to 9.7%) and a BPF in 32 (4.5%; 95% CI, 3.1% to 6.3%). Univariate analysis demonstrated that the development of empyema was adversely affected by benign disease (p = 0.0001), lower preoperative forced expiratory volume in 1 second (FEV1; p < 0.01) and diffusion capacity of lung to carbon monoxide (DLCO; p = 0.0001), lower preoperative serum hemoglobin (p = 0.05), right pneumonectomy (p = 0.0109), bronchial stump reinforcement (p = 0.007), completion pneumonectomy (p < 0.01), timing of chest tube removal (p = 0.01), and the amount of blood transfusions (p < 0.01). Similarly, the development of BPF was significantly associated with benign disease (p = 0.03), lower preoperative FEV1 (p = 0.03) and DLCO (p = 0.01), right pneumonectomy (p < 0.0001), bronchial stump reinforcement (p = 0.03), timing of chest tube removal (p = 0.004), increased intravenous fluid in the first 12 hours (p = 0.04), and blood transfusions (p = 0.04). Bronchial stump closure with staples had a protective effect against BPF compared with suture closure (p = 0.009). No risk factors were identified as being jointly significant in multivariate analysis. CONCLUSIONS: Multiple perioperative factors were associated with an increased incidence of empyema and BPF after pneumonectomy. Prophylactic reinforcement of the bronchial stump with viable tissue may be indicated in those patients suspected at higher risk for either empyema or BPF.

Ruptured abdominal aortic aneurysms: the excessive mortality rate of conventional repair.

OBJECTIVE: Rupture of abdominal aortic aneurysms (AAAs) remains lethal. In a report of patients treated in the 1980s, we recommended aggressive management. Our continued experience prompted us to reevaluate this policy. METHODS: We reviewed clinical variables affecting outcome, morbidity, mortality, and trends in mortality of all patients managed at our institution with ruptured AAAs between January 2, 1980, and November 30, 1998. RESULTS: The study group included 413 consecutive patients, 339 men and 74 women. The mean age was 74.3 years (range, 49-96); 116 (28%) patients were older than 80 years. AAA was diagnosed before rupture in 119 (29%) patients. Eighty (19%) patients had preoperative cardiac arrest. Twenty-nine (7%) patients died before operation; 65 (17%) died during the operation. The surgical mortality rate (30-day) was 37%; the overall mortality rate was 45% and was higher in women (68%) than in men (40%) (P <.001). Advanced age, APACHE (Acute Physiology and Chronic Health Evaluation) II score, initial hematocrit, and preoperative cardiac arrest were associated multivariately with 30-day mortality rates by means of stepwise logistic regression (P <.05). Twelve (23%) of 53 patients with cardiac arrest survived the operation. Logistic regression, adjusted for age, sex, and APACHE II score, demonstrated a decrease in overall and 30-day mortality rates (P <.001) over 18 years. The mean overall mortality rate was 51% from 1980 to 1984 and 42% from 1994 to 1998. CONCLUSIONS: The mortality rate of ruptured AAAs remains excessive, despite improvement over 18 years. Patients older than 80 years with shock or cardiac arrest have the highest mortality rate and should be evaluated for possible endovascular treatment. Because the diagnosis of AAA was unknown in more than 70% of patients, screening of the high-risk population and elective repair are recommended.

Pneumonectomy for malignant disease: factors affecting early morbidity and mortality.

OBJECTIVE: The purpose of this report is to analyze factors affecting morbidity and mortality after pneumonectomy for malignant disease. METHODS: We retrospectively reviewed the cases of all patients who underwent pneumonectomy for malignancy at the Mayo Clinic. Between January 1, 1985, and September 30, 1998, 639 patients (469 men and 170 women) were identified. Median age was 64 years (range 20 to 86 years). Indication for pneumonectomy was primary lung cancer in 607 (95.0%) patients and metastatic disease in 32 (5.0%). Factors affecting morbidity and mortality were analyzed by univariate and multivariate analysis. RESULTS: Cardiopulmonary complications occurred in 245 patients (38.3%; 95% confidence interval 34.6%-42.2%). Factors adversely affecting morbidity with univariate analysis included age (P <.0001), male sex (P =.04), associated respiratory (P =.02) or cardiovascular disease (P <.0001), cigarette smoking (P =.02), decreased vital capacity (P =.01), forced expiratory volume in 1 second (P <.0001), forced vital capacity (P =.002), diffusion capacity of the lung to carbon monoxide (P =.005), oxygen saturation (P <.05), arterial PO (2) (P =.007), preoperative radiation (P =.02), bronchial stump reinforcement (P =.007), crystalloid infusion (P =.01), and blood transfusion (P =.02). Factors adversely affecting morbidity with multivariate analysis included age (P =.0001), associated cardiovascular disease (P =.001), and bronchial stump reinforcement (P =.0005). There were 45 deaths (7.0%; 95% confidence intervals 5.2%-9.3%). Factors adversely affecting mortality with univariate analysis included associated cardiovascular (P <.0001) or hematologic disease (P <.005), lower preoperative serum hemoglobin level (P =.004), preoperative chemotherapy (P =.01), decreased diffusion capacity of lung to carbon monoxide (P =.002), right pneumonectomy (P =.0006), extended resection (P =.04), bronchial stump reinforcement (P =.007), and crystalloid infusion (P =.01). Factors affecting mortality with multivariate analysis included hematologic disease (P =.01), lower preoperative serum hemoglobin (P =.003), and completion pneumonectomy (P =.01). CONCLUSION: Multiple factors adversely affected morbidity and mortality after pneumonectomy for malignant disease. Appropriate selection and meticulous perioperative care are paramount to minimize risks in those patients who require pneumonectomy.

Detection of herpes simplex virus DNA in genital and dermal specimens by LightCycler PCR after extraction using the IsoQuick, MagNA Pure, and BioRobot 9604 methods.

We evaluated two automated systems, MagNA Pure (Roche Molecular Biochemicals, Indianapolis, Ind.) and BioRobot 9604 (Qiagen, Inc., Chatsworth, Calif.) as effective replacements for the manual IsoQuick method (Orca Research, Inc., Bothell, Wash.) for extraction of herpes simplex virus (HSV) DNA from dermal and genital tract specimens prior to analysis by LightCycler PCR. Of 198 specimens (152 genital, 46 dermal), 92 (46.2%) were positive for HSV DNA by LightCycler PCR after automated extraction of specimens with either the MagNA Pure or BioRobot 9604 instrument. The manual IsoQuick method yielded HSV DNA (total n = 95) from three additional specimens that were negative by the automated method (P = 0.25, sign test). Although the mean numbers of LightCycler PCR cycles required to reach positivity differed statistically significantly among all three of the methods of extraction, the estimated means differed by no more than 1.5 cycles (P < 0.05). Seventy (76%) of the 92 specimens that were LightCycler PCR positive by all three extraction methods were also positive by shell vial cell culture assay. HSV DNA was detected by a lower LightCycler PCR cycle number (26.1 cycles) in specimens culture positive for the virus than in culture-negative samples (33.3 cycles) (P < 0.0001). The manual IsoQuick and automated MagNA Pure and BioRobot 9604 methods provide standardized, reproducible extraction of HSV DNA for LightCycler PCR. The decision to implement a manual versus an automated procedure depends on factors such as costs related to the number of specimens processed rather than on the minimal differences in the technical efficiency of extraction of nucleic acids among these methods.

Surgical reconstruction of iliofemoral veins and the inferior vena cava for nonmalignant occlusive disease.

PURPOSE: Venous reconstructions are rarely performed, and factors affecting long-term results of bypass grafts implanted in the venous system are not well defined. In this report we updated our experience. METHODS: The clinical data of all patients who underwent venous reconstruction for iliofemoral or inferior vena caval (IVC) occlusion due to nonmalignant disease between January 1985 and June 1999 were retrospectively reviewed. Patients were classified, and outcomes were compared according to the guidelines of the Joint Vascular Societies. RESULTS: Forty-two patients, 23 males and 19 females (mean age, 40 years; range, 16-81), underwent 44 venous reconstructions. Thirty-six patients had limb swelling or venous claudication, 38 had pain, and 14 had healed or active ulcers. The cause of obstruction was congenital in two and acquired in 40 (deep vein thrombosis, 25; trauma, 5; retroperitoneal fibrosis, 4; IVC occlusion devices, 4; others, 2). Eighteen patients underwent saphenous vein crossover grafts (Palma procedure), 17 had expanded polytetrafluoroethylene (ePTFE) grafts implanted (femorocaval, 8; iliocaval, 5; crossfemoral, 3; cavoatrial, 1), 6 patients had spiral vein grafts (5 iliac/femoral and 1 cavoatrial), and 1 underwent femoral vein patch angioplasty. Clinical follow-up averaged 3.5 years (median, 2.5), and graft follow-up with imaging studies averaged 2.6 years (median, 1.6). Seven patients were lost to follow-up. The secondary 3-year patency rate for all reconstructions was 62%. Palma procedures had a 4-year patency rate of 83%. The secondary patency rate of iliocaval and femorocaval ePTFE bypass grafts at 2 years was 54%. The secondary patency was lower in patients with an arteriovenous fistula (P =.023). All ePTFE grafts had a 45% patency rate at 2 years, not significantly different from saphenous vein grafts (83%, P =.16). Clinical scores improved with graft patency (median, 0.0 vs 1.5; P =.044). CONCLUSIONS: Venous reconstructions for iliofemoral or IVC obstruction offer 3-year patency rates of 62%. The Palma procedure with autologous saphenous vein had the best long-term patency, whereas long-term success with ePTFE was moderate. The use of an arteriovenous fistula to improve graft patency remains controversial.

Limb salvage after successful pedal bypass grafting is associated with improved long-term survival.

OBJECTIVES: Assessments of outcome after reconstruction for critical limb ischemia frequently ignore functional result and long-term morbidity and mortality. This study was undertaken to identify factors affecting long-term clinical outcome and survival after pedal bypass grafting. METHODS: The clinical data of 256 consecutive patients who underwent pedal bypass grafting for critical limb ischemia over a 12-year period were retrospectively analyzed. RESULTS: A total of 174 men and 82 women (median age, 70 years; range, 30-91 years) underwent 280 pedal bypass graft placements with autologous vein. Seventy-five percent of the patients were diabetic, and 20% had renal insufficiency (serum creatinine level > 2 mg/dL). The in-hospital mortality rate was 1.6% (4/256). The mean follow-up was 2.7 years (range, 0.1-10.1 years). Rates of primary and secondary patency, limb salvage, and survival at 5 years were 58%, 71%, 78%, 60%, respectively. A total of 160 limbs (57%) required additional interventions. Nineteen early graft thrombectomies/revisions and nine early amputations were performed. One hundred thirty-eight late interventions included 31 graft salvage procedures, 27 wound debridements, and 34 minor and 42 major amputations. At last follow-up or death, 219 (78%) limbs were being used for ambulation. End-stage renal disease (ESRD) and composite vein grafts predicted limb loss (P <.001, P <.001, respectively). Overall survival at 5 years was 60%. Survival after amputation was 79%, 53%, and 26% at 1, 3, and 5 years. Amputation and ESRD predicted higher mortality (P =.014, P =.0001, respectively). CONCLUSIONS: Pedal bypass grafting resulted in good functional limb salvage, but at the expense of multiple interventions in more than half the cases. ESRD and composite vein graft were associated with poor long-term limb salvage. Amputation after bypass grafting was associated with significantly worse long-term survival.