Genetic Contribution in Low Back Pain: A Prospective Genetic Association Study.

OBJECTIVES: Chronic pain is one of the most common reasons individuals seek medical attention. It is a major issue because of the wide interindividual variability in the analgesic response. This might be partly explained by the presence of variants in genes encoding molecules involved in pharmacodynamics and pharmacokinetics. The aim was to analyze opioid effectiveness in chronic low back pain (CLBP) relief after opioid titration, unveiling the impact of pharmacogenetics. METHODS: The study included 231 opioid-naïve patients from the Spine Unit; age 63 ± 14 years, 64% female, body mass index 29 ± 6 kg/m2 , visual analog scale pain intensity score 73 ± 16 mm. Clinical data were collected at baseline, 3 months after opioid titration, and after 2 to 4 years of follow-up concerning pain (intensity and relief), quality of life, disability, comorbidities, and drug prescription (opioid dose, rotations, and adverse events). The genotype influence of OPRM1, COMT, UGT2B7, ABCB1, KCNJ6, and CYP3A5*3A in analgesic response was analyzed by reverse-transcription polymerase chain reaction genotyping. RESULTS: Patients with the COMT G472A-AA genotype (rs4680) and KCNJ6 A1032G-A allele (rs2070995) CLBP responded differently to opioid titration, with higher pain intensity requiring higher dosing. Furthermore, GG- genotypes of A118G (OPRM1, rs1799971) and A854G (UGT2B7, rs776746) influenced the neuropathic component. After opioid titration, CLBP intensity, neuropathic component, low back pain disability, anxiety, and depression significantly decreased, while quality of life improved. CONCLUSION: Single-nucleotide polymorphisms in genes involved in pain transmission and opioid metabolism might predispose to exaggerated sensitivity and differences in the opioid analgesic effect in patients with CLBP. We encourage clinical trials for their clinical application in chronic pain management.

Norfloxacin modulates the inflammatory response and directly affects neutrophils in patients with decompensated cirrhosis.

BACKGROUND & AIMS: Patients with cirrhosis undergoing selective intestinal decontamination with norfloxacin show a reduction in serum cytokine levels, probably because of a combined effect of norfloxacin on bowel flora and neutrophils. METHODS: Thirty-one patients with cirrhosis receiving norfloxacin (400 mg/day) were included. Blood samples were collected at 0.5-4 hours (peak samples group, n = 47) and at 22-24 hours (trough samples group, n = 84) after dose. Fifty-nine ascitic fluid samples were obtained. Single doses of norfloxacin and trimethoprim/sulfamethoxazole were administered to 13 and 5 patients, respectively, (temporal profile group) and samples were collected at 0, 0.5, 1, 1.5, 2, 4, and 24 hours. Norfloxacin, trimethoprim/sulfamethoxazole, cytokines, nitric oxide, expression levels of nuclear factor (NF)-kappaB and inhibitor of NF-kappaB (IkB-alpha), neutrophil oxidative burst, and rate of apoptotic events were determined. RESULTS: All samples were bacterial DNA negative and had no significant levels of lipopolysaccharide. Serum and ascitic levels of tumor necrosis factor-alpha, interferon-gamma, interleukin-12, and nitric oxide were significantly lower in peak than in trough samples. A correlation was present between serum norfloxacins concentrations and tumor necrosis factor-alpha (r = -0.68; P < .001), interferon-gamma (r = -0.66; P < .001), interleukin-12 (r = -0.66; P < .001), and nitric oxide (r = -0.68; P < .001). Serum norfloxacin's highest concentrations (1 +/- 0.5 microg/mL) were achieved at 1-2 hours and concurred in time with the lower levels of cytokines and nitric oxide. Intracellular norfloxacin's highest levels (2 +/- 1 microg/mL/10(7) cells) were observed at 2 hours and concurred with a lower NF-kappaB expression, a reduced anion superoxide generation, and apoptotic rate in response to phorbol myristate acetate. Trimethoprim/sulfamethoxazole did not significantly modulate cytokine expression. CONCLUSIONS: Norfloxacin but not trimethoprim/sulfamethoxazole modulates inflammatory response and directly affects neutrophils in patients with cirrhosis.

Bacterial DNA in patients with cirrhosis and noninfected ascites mimics the soluble immune response established in patients with spontaneous bacterial peritonitis.

UNLABELLED: Bacterial infections and severity of associated inflammatory reaction influence prognosis in patients with advanced cirrhosis. We compared the innate immune response to bacterial DNA (bactDNA) translocation with that caused by viable bacteria translocation in patients with spontaneous bacterial peritonitis and the relationship between the cytokine response and serum levels of bactDNA. The bactDNA translocation was investigated in 226 patients with cirrhosis and noninfected ascites, 22 patients with spontaneous bacterial peritonitis, and 10 patients with ascites receiving continuous norfloxacin. Serum and ascitic fluid tumor necrosis factor alpha, interferon-gamma, interleukin-12, and nitric oxide metabolites were measured via enzyme-linked immunosorbent assay. Bacterial genomic identifications were made via amplification and sequencing of the 16S ribosomal RNA gene and digital quantization with DNA Lab-on-chips. The bactDNA was present in 77 noninfected patients (34%) and in all cases of spontaneous bacterial peritonitis, even in those with culture-negative ascitic fluid. No patient receiving norfloxacin showed bactDNA translocation. Levels of all cytokines were similar in patients with bactDNA translocation or spontaneous bacterial peritonitis and significantly higher than in patients without bactDNA or in those receiving norfloxacin. Serum bactDNA concentration paralleled levels of all cytokines and nitric oxide in a series of patients with bactDNA translocation or spontaneous bacterial peritonitis followed during 72 hours. Antibiotic treatment in the series of patients with spontaneous bacterial peritonitis did not abrogate bactDNA translocation in the short term. CONCLUSION: bactDNA translocation-associated cytokine response is indistinguishable from that in patients with spontaneous bacterial peritonitis and is dependent on bactDNA concentration. Norfloxacin abrogates bactDNA translocation and cytokine response.

Serum and ascitic fluid bacterial DNA: a new independent prognostic factor in noninfected patients with cirrhosis.

UNLABELLED: We tested the hypothesis that the presence of bacterial DNA (bactDNA) in ascitic fluid and serum is associated with decreased survival in patients with cirrhosis. In a prospective, multicenter study, we analyzed the clinical evolution of 156 patients with cirrhosis and ascites (first or recurrence) with lower than 250 polymorphonuclear cells (PMN)/muL, negative ascites bacteriological culture, and absence of other bacterial infections being admitted for evaluation of large-volume paracentesis, according to the presence of bactDNA at admission. Survival, causes of death, and successive hospital admissions were determined during a 12-month follow-up period. BactDNA was detected in 48 patients. The most prevalent identified bactDNA corresponded to Escherichia coli (n = 32/48 patients, 66.6%). Patients were followed for 12 months after inclusion and in this period 34 patients died: 16 of 108 (15%) bactDNA negative versus 18 of 48 (38%) bactDNA positive (P = 0.003). The most frequent cause of death was acute-on-chronic liver failure in both groups (7/16 and 9/18 in patients without or with bactDNA, respectively), although more prevalent in the first month of follow-up in patients with presence of bactDNA (0 versus 4/7). When considering patients with model for end-stage liver disease (MELD) score less than 15, mortality was significantly higher in those with presence of bactDNA. Spontaneous bacterial peritonitis developed similarly in patients with or without bactDNA at admission. CONCLUSION: The presence of bactDNA in a patient with cirrhosis during an ascitic episode is an indicator of poor prognosis. This fact may be related to the development of acute-on-chronic liver failure at short term and does not predict the development of spontaneous bacterial peritonitis.

Causality assessment of liver injury after chronic oral amiodarone intake.

BACKGROUND/AIM: The number of patients receiving amiodarone will increase in future years. As clinically significant hepatotoxicity associated with oral amiodarone is infrequent and difficult to predict, a new Bayesian-developed model is proposed to help in the causality assessment of amiodarone-induced liver injury. METHODS: Incidence of abnormal liver enzymes in patients receiving amiodarone was obtained from placebo controlled clinical trials. Published case reports of amiodarone-induced hepatotoxicity were identified through a literature search. Maximum number of expected hepatotoxicity cases in amiodarone and placebo-treated patients was calculated using Poisson distribution. The calculated odds ratio was used as a Prior Odds (PrO) to subsequent quantification, using a Bayesian-approach, of individual amiodarone-induced hepatotoxicity likelihood. RESULTS: PrO of amiodarone-induced hepatotoxicity was 0.48. Thirty nine amiodarone-associated hepatotoxicity case reports were retrieved. Half of published case reports developed an irreversible damage. The amiodarone Bayesian model combining information about latency period and period of remission, together with analytical parameters properly defines the toxicity profile shown in published case reports. The analytical pattern defined by this model is different from the one expected if liver injury in published cases was caused by other etiologies. CONCLUSIONS: A method based on a Bayesian-approach, which links information from clinical trials with clinical hepatotoxicity profile from published case reports can be a useful tool for amiodarone-induced liver injury causality assessment. At present, this method is limited due to scarcity and quality of available data. Further efforts are needed to improve model ability in order to identify amiodarone-induced liver injury.

Postoperative bilateral reading performance with 4 intraocular lens models: six-month results.

PURPOSE: To compare bilateral reading performance within the first 6 months after implantation of 4 intraocular lens (IOL) models. SETTING: Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain, and University Eye Clinic, Paracelsus Medical University, Salzburg, Austria. DESIGN: Comparative case series. METHODS: Patients had bilateral phacoemulsification and implantation of Acri.Smart 48S monofocal, Acrysof Restor SN6AD3 apodized multifocal, Acri.LISA 366D diffractive multifocal, or Rezoom refractive multifocal IOLs. Bilateral reading performance with and without near correction was evaluated preoperatively and postoperatively using the Salzburg Reading Desk. RESULTS: The study comprised 304 eyes of 152 patients 51 to 90 years old. All groups had a significant improvement in uncorrected and corrected distance visual acuities postoperatively (P≤.01). The apodized multifocal and diffractive multifocal groups had significantly better uncorrected reading acuity than the monofocal and refractive multifocal groups 1 month and 6 months postoperatively (P<.01). Uncorrected reading speed was significantly worse in the refractive multifocal group than in the monofocal group at 1 month (P<.01). The monofocal group had the greatest uncorrected reading distance at 1 month and 6 months (P<.01). CONCLUSION: Multifocal IOLs with a diffractive component provided a comparable reading performance that was significantly better than the one obtained with refractive multifocal and monofocal IOLs.

The diagnosis of drug-induced liver disease.

The diagnosis of drug-induced liver injury is often one of exclusion with initial suspicion based on circumstantial evidence. The natural history, characteristics and limitations of this exclusion process are revised. Also, the numerous published attribution algorithms for evaluation of drug-related liver abnormalities are described and their characteristics and differences are illustrated with true patients from our clinical experience. Situations that complicate the diagnosis such as age, sex, concomitant use of other drugs, genetic polymorphism in metabolic pathways involved in activation or disposition of therapeutic drugs and drug-drug interactions are described. Finally, developing approach to diagnosis of drug-induced liver injury, different of attribution algorithms, are evaluated and explained using a new method based in a Bayesian approach developed and published by the authors. The authors' vision of all these potential advances and their clinical utility is provided.