Anita Conforti

Susceptibility to Amoxicillin-Clavulanate-Induced Liver Injury is Influenced by Multiple HLA Class I and II Alleles

BACKGROUND & AIMS Drug-induced liver injury (DILI), especially from antimicrobial agents, is an important cause of serious liver disease. Amoxicillin-clavulanate (AC) is a leading cause of idiosyncratic DILI, but little is understood about genetic susceptibility to this adverse reaction. METHODS We performed a genome-wide association study using 822,927 single nucleotide polymorphism (SNP) markers from 201 White European and US cases of DILI following AC administration (AC-DILI) and 532 population controls, matched for genetic background. RESULTS AC-DILI was associated with many loci in the major histocompatibility complex. The strongest effect was with an HLA class II SNP (rs9274407, P=4.8×10(-14)), which correlated with rs3135388, a tag SNP of HLA-DRB1*1501-DQB1*0602 that was previously associated with AC-DILI. Conditioned on rs3135388, rs9274407 is still significant (P=1.1×10(-4)). An independent association was observed in the class I region (rs2523822, P=1.8×10(-10)), related to HLA-A*0201. The most significant class I and II SNPs showed statistical interaction (P=.0015). High-resolution HLA genotyping (177 cases and 219 controls) confirmed associations of HLA-A*0201 (P=2×10(-6)) and HLA-DQB1*0602 (P=5×10(-10)) and their interaction (P=.005). Additional, population-dependent effects were observed in HLA alleles with nominal significance. In an analysis of autoimmune-related genes, rs2476601 in the gene PTPN22 was associated (P=1.3×10(-4)). CONCLUSIONS Class I and II HLA genotypes affect susceptibility to AC-DILI, indicating the importance of the adaptive immune response in pathogenesis. The HLA genotypes identified will be useful in studies of the pathogenesis of AC-DILI but have limited utility as predictive or diagnostic biomarkers because of the low positive predictive values.

Adverse drug reactions related to the use of fluoroquinolone antimicrobials: an analysis of spontaneous reports and fluoroquinolone consumption data from three italian regions.

AbstractObjective: To analyse and compare with one another and with other antibacterial drugs the adverse drug reactions (ADRs) of the different fluoroquinolones currently used in Italy, spontaneously reported from doctors in three northern Italian regions. Methods: The data on fluoroquinolones and other antibacterials were obtained from the spontaneous reporting system database of Emilia Romagna, Lombardy and the Veneto, which are the principal contributors to the Italian spontaneous surveillance system. The fluoroquinolone ADRs with a causality assessment of certain, probable or possible (according to WHO criteria), reported between January 1999 and December 2001, were selected and toxicity profiles of individual drugs were described and compared with one another. The reports were also correlated with sex and age of patients and with regional prescription data to estimate individual fluoroquinolone reporting rate of adverse events. Results: During the study period, 10 011 reports were received by the system (a mean annual reporting rate of approximately 185 per million inhabitants): 1920 referred to systemic antimicrobials, of which 432 (22.5%) involved fluoroquinolones.Pefloxacin was associated with the highest reporting rate (982 reports/daily defined dose/1000 inhabitants/day), followed by moxifloxacin (356), rufloxacin (221) and lomefloxacin (196). The most frequently reported reactions to fluoroquinolones involved the skin, but their percentage (25%) was significantly lower (p < 0.01) than those of other systemic antimicrobials (58.5%), whereas the percentages of reactions involving the central nervous (12.2 vs 3.6%), musculoskeletal (14.7 vs 0.3%) and psychiatric systems (9.3 vs 1.8%) were significantly higher (p < 0.01). We found some significant differences in the safety profiles of individual fluoroquinolones: ciprofloxacin was more frequently associated with skin reactions (p < 0.01), levofloxacin and pefloxacin with musculoskeletal (p < 0.01), and rufloxacin with psychiatric disorders (p < 0.05). Levofloxacin was the fluoroquinolone associated with the highest rate of serious tendon disorders; phototoxic reactions were more frequent with lomefloxacin, and toxic epidermal necrolysis and Stevens-Johnson syndrome were seen only with ciprofloxacin. Conclusions: The differences in the safety profiles should be taken into account when prescribing a fluoroquinolone to individual patients.

Immunology and Homeopathy. 2. Cells of the Immune System and Inflammation

Here we describe the results of some experimental laboratory studies aimed at verifying the efficacy of high dilutions of substances and of homeopathic medicines in models of inflammation and immunity. Studies carried out on basophils, lymphocytes, granulocytes and fibroblasts are reviewed. This approach may help to test under controlled conditions the main principles of homeopathy such as ‘similarity’ of drug action at the cellular level and the effects of dilution/dynamization on the drug activity. The current situation is that few and rather small groups are working on laboratory models for homeopathy. Regarding the interpretation of data in view of the simile principle, we observe that there are different levels of similarity and that the laboratory data give support to this principle, but have not yet yielded the ultimate answer to the action mechanism of homeopathy. Evidence of the biological activity in vitro of highly diluted-dynamized solutions is slowly accumulating, with some conflicting reports. It is our hope that this review of literature unknown to most people will give an original and useful insight into the ‘state-of-the-art’ of homeopathy, without final conclusions ‘for’ or ‘against’ this modality. This kind of uncertainty may be difficult to accept, but is conceivably the most open-minded position now.

Immunology and homeopathy. 3. Experimental studies on animal models.

A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti-inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.

Review: Copper and inflammation — a possible rationale for the pharmalogical manipulation of inflammatory discorders

Acute and chronic inflammations are characterized, among other features, by changes in the metabolism of copper and by a widespread responsiveness to the therapy with copper-containing molecules.The exact map of inflammation-induced copper movements as well as the role played by the metal in the pathogenesis of inflammatory disorders are, however, far from being clear, and this is especially true in the case of chronic processes.Nevertheless the present knowledge suggests that the ‘copper approach’ may provide a new way for coping with the problem of anti-inflammatory/anti-arthritic therapies. The administration of exogenous copper, and thein vivo manipulation of the endogenous metal levels are proposed as two possible therapeutic strategies, not necessarily mutually exclusive.For a better understanding of the value of such an approach, further research work is needed, especially to attain a more detailed know-how on the involved chemical forms, distribution and functions of copper in both normal as well as inflamed organisms.

Immunology and homeopathy. 1. Historical background.

Homeopathy was born as an experimental discipline, as can be seen from the enormous amount of homeopathic data collected over more than two centuries. However, the medical tradition of homeopathy has been separated from that of conventional science for a long time. Conventional scientific wisdom dictates that homeopathy should have no effect above placebo but experiments on ultra-high dilutions of solutes together with some clinical data suggest the intriguing possibility that it might do in some circumstances. Today, an osmotic process between disciplines, previously seen as in conflict, is facilitated because over the last few decades homeopathy has initiated the methods of current medical science and a substantial number of experimental studies—at molecular, cellular and clinical levels—are available. One area of dialogue and of common progress is that of inflammation and immunity, probably because these are closely related to the traditional ‘vital force’ of the bodys self-healing power. In a series of papers we review the historical origins of homeopathy, the laboratory and animal models related to the field of immunopharmacology, the clinical evidence in favor and against the use of homeopathy in the inflammatory diseases and the hypotheses regarding its action mechanism(s). Finally, we will enlighten the specific characteristics of the homeopathic approach, which places great emphasis on identifying a cure for the whole organism.

Immunology and Homeopathy. 5. The Rationale of the ‘Simile’

The foundation of homeopathic medicine is the ‘Similia Principle’, also known as the ‘Principle of Similarity’ or also as the ‘Simile’, which reflects the inversion of pharmacological effects in healthy subjects as compared with sick ones. This article describes the inversion of effects, a widespread medical phenomenon, through three possible mechanisms: non-linearity of dose–response relationship, different initial pathophysiological states of the organism, and pharmacodynamics of body response to the medicine. Based on the systemic networks which play an important role in response to stress, a unitary and general model is designed: homeopathic medicines could interact with sensitive (primed) regulation systems through complex information, which simulate the disorders of natural disease. Reorganization of regulation systems, through a coherent response to the medicine, could pave the way to the healing of the cellular, tissue and neuro-immuno-endocrine homeodynamics. Preliminary evidence is suggesting that even ultra-low doses and high-dilutions of drugs may incorporate structural or frequency information and interact with chaotic dynamics and physical-electromagnetic levels of regulation. From the clinical standpoint, the ‘simile’ can be regarded as a heuristic principle, according to which the detailed knowledge of pathogenic effects of drugs, associated with careful analysis of signs and symptoms of the ill subject, could assist in identifying homeopathic remedies with high grade of specificity for the individual case.

Anti-inflammatory potency and gastrointestinal toxicity of a new compound, nitronaproxen

Naproxen and its derivative nitronaproxen at the doses of 5 and 10 mg kg-1 were compared for their acute anti-inflammatory efficacy in a carrageenan oedema model and gastrointestinal toxicity in rats. Moreover, the effects of the two drugs were evaluated in the adjuvant arthritis, after chronic doses of 4 and 8 mg kg-1 administered orally for 18 days. The oedema reduction was maintained much longer (until 5 h) with nitronaproxen; the inhibition of arthritis was 50% or more with both doses of the examined drugs. From the histological examination of the stomachs, an extensive mucosal vasocongestion and haemorrhagic lesions have been observed in some rats treated with naproxen. The percentages of animals with ulcers were 50, 100 and 10 with naproxen 6 and 18 mg kg-1 and nitronaproxen 54 mg kg-1 respectively. A better gastrointestinal tolerability has been observed in arthritic and oedemic rats treated with nitronaproxen compared to naproxen: this could be due to the presence of nitric oxide that acts in maintaining the tissue perfusion and integrity.

Identifying Adverse Drug Reactions Associated with Drug-Drug Interactions: Data Mining of a Spontaneous Reporting Database in Italy

AbstractBackground: Drug-drug interactions (DDIs) are an important cause of adverse drug reactions (ADRs). Many studies have recently considered this issue, but most of them focus only on potential interactions and are often related to the hospital setting. A spontaneous reporting database could be a valuable resource for detection of ADRs associated with DDIs; however, data in the literature are limited. Objective: To detect those patients treated with potentially interacting drugs and the cases where reported adverse reactions are a possible consequence of DDIs, using an Italian spontaneous reporting database. Methods: The data were obtained from a database containing all reports of suspected ADRs from five Italian regions (January 1990 to December 2007) that are the main contributors to the Italian spontaneous reporting system. All reports containing at least two drugs, reported as being suspected of causing the ADR or as concomitant medication, were selected and a list of drug pairs was drawn up. We performed a search to verify which drug pairs are considered a potential DDI, using the Internet version of the DRUGDEX® system. For each report containing a potential DDI, we verified whether the description of the adverse reaction corresponded to the interaction effect. Results: The database contained 45 315 reports, of which 17 700 (39.1%) had at least two reported drugs. We identified 5345 (30.2%) reports with potential DDIs, and in 1159 (21.7%) of these reports a related ADR was reported. The percentage of reports with potential DDIs increased in relation to the number of concomitantly administered drugs, ranging from 9.8% for two drugs to 88.3% for eight or more drugs. The percentages of serious or fatal reports of ADRs associated with a DDI were significantly higher than other reports analysed. The mean age, percentage of male patients and the mean number of drugs were also significantly higher in reports with DDIs than in other reports. In 235 of 1159 reports (20.3%), both interacting drugs were recognized as suspect by the reporter. This percentage varies in relation to the drugs involved, ranging from 2% to about 65%. The most frequently reported interaction was digoxin and diuretics, but no fatal ADRs were reported with this combination. The combination of anticoagulant and antiplatelet agents was responsible for the greatest number of serious reactions and deaths. Conclusions: This study validates that spontaneous reporting, despite its limitations, can be an important resource for detecting ADRs associated with the concomitant use of interacting drugs. Moreover, our data confirm that DDIs could be a real problem in clinical practice, showing that more than one in five patients exposed to a potential DDI experienced a related ADR.

Drug-induced anaphylaxis : case/non-case study based on an italian pharmacovigilance database.

AbstractObjective: To identify the number of cases of anaphylaxis reported in association with different classes of drugs and compare it with other reports contained in the same database. Methods: The data were obtained from a database containing all of the spontaneous reports of adverse drug reactions (ADRs) coming from the Italian regions of Emilia Romagna, Lombardy and the Veneto, which are the main contributors to the Italian spontaneous surveillance system. The ADRs reported between January 1990 and December 2003 with a causality assessment of certainly, probably or possibly drug related (according to the WHO criteria) were analysed using a case/non-case design. The cases were defined as the reactions already coded by the WHO preferred terms of ‘anaphylactic shock’ or ‘anaphylactoid reaction’ (this last term also included anaphylactic reaction) and those with a time of event onset that suggested an allergic reaction and involved at least two of the skin, respiratory, gastrointestinal, CNS or cardiovascular systems; the non-cases were all of the other ADR reports. The frequency of the association between anaphylaxis and the suspected drug in comparison with the frequency of anaphylaxis associated to all of the other drugs was calculated using the ADR reporting odds ratio (ROR) as a measure of disproportionality. Results: Our database contained 744 cases (including 307 cases of anaphylactic shock with 10 deaths) and 27 512 non-cases. The percentage of anaphylaxis cases reported in inpatients was higher than that among outpatients (59.1% vs 40.9%). This distribution is significantly different from that of the other ADR reports that mainly refer to outpatients. After intravenous drug administrations, anaphylactic shock cases were more frequent than anaphylactoid reactions or other ADRs, but more than one-third of these reactions were caused by an oral drug. Blood substitutes and radiology contrast agents had the highest RORs. Among the systemic antibacterial agents, anaphylaxis was disproportionally reported more often for penicillins, quinolones, cephalosporins and glycopeptides, but diclofenac was the only NSAID with a significant ROR. As a category, vaccines had a significantly lower ROR, thus indicating that anaphylaxis is reported proportionally less than other ADRs. Conclusions: Anaphylaxis is a severe ADR that may also occur with commonly used drugs. It represents 2.7% of all of the ADRs reported in an Italian spontaneous reporting database.