Kinetics of serum cytokines reflect changes in the severity of chronic hepatitis C presenting minimal fibrosis

Our aims were to measure the kinetics of serum tumour necrosis alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) levels as markers of progression of disease in nontreated chronic hepatitis C virus (HCV)-infected patients with minimal or no fibrosis and minimal histology activity index (HAI) scores. Our study group consisted of 56 patients diagnosed with minimal (1) or no fibrosis (0) and minimal HAI (0-1) on their first biopsy as defined by Knodell and METAVIR scores. We compared their initial (entry of study) cytokine levels with a group of 103 HCV controls with minimal (0-1) to mild fibrosis (0-3) and mild HAI (5.5). Serum TNF-alpha and TGF-beta levels were measured by enzyme-linked-immunosorbent-assay. A significant difference was seen in TNF-alpha levels at baseline in the study group vs. controls. Regardless of their HAI, there was a correlation between TGF-beta and degree of fibrosis. As shown by their biopsies, during the 3 years (from entry to follow up), many of the patients that initially had minimal fibrosis progressed to higher degree of fibrosis. This progression is paralleled by an increase in TGF-beta levels when comparing initial and follow-up levels. In conclusion, serum TNF-alpha reflects the progression of inflammation as seen in liver biopsies and TGF-beta reflects the degree of fibrosis in HCV patients.

Kinetics of serum cytokines reflect changes in the severity of chronic hepatitis C presenting minimal fibrosis

Our aims were to measure the kinetics of serum tumour necrosis alpha (TNF-alpha) and transforming growth factor beta (TGF-beta) levels as markers of progression of disease in nontreated chronic hepatitis C virus (HCV)-infected patients with minimal or no fibrosis and minimal histology activity index (HAI) scores. Our study group consisted of 56 patients diagnosed with minimal (1) or no fibrosis (0) and minimal HAI (0-1) on their first biopsy as defined by Knodell and METAVIR scores. We compared their initial (entry of study) cytokine levels with a group of 103 HCV controls with minimal (0-1) to mild fibrosis (0-3) and mild HAI (5.5). Serum TNF-alpha and TGF-beta levels were measured by enzyme-linked-immunosorbent-assay. A significant difference was seen in TNF-alpha levels at baseline in the study group vs. controls. Regardless of their HAI, there was a correlation between TGF-beta and degree of fibrosis. As shown by their biopsies, during the 3 years (from entry to follow up), many of the patients that initially had minimal fibrosis progressed to higher degree of fibrosis. This progression is paralleled by an increase in TGF-beta levels when comparing initial and follow-up levels. In conclusion, serum TNF-alpha reflects the progression of inflammation as seen in liver biopsies and TGF-beta reflects the degree of fibrosis in HCV patients.

The science of health technology assessment: the safety perspective

Efforts to enhance the reporting and analysis of drug reactions have increased over recent years. Research into the pathogenesis, diagnosis and epidemiology has yielded important insights, yet major gaps in our management of drug safety still exist. Drug-induced diseases are an important cause of morbidity and mortality. Current ad hoc reporting systems fail to collect more than 10% of even the most serious of reactions. Drug reaction syndromes lack universally accepted definitions and names. Effective therapies for drug-induced diseases are few and poorly studied. Information about how to diagnose and treat drug-induced diseases is not reaching practitioners. Stakeholders, including regulatory agencies, funding agencies, the pharmaceutical industry, physicians, pharmacists and patient advocacy groups, need to work together to improve the systematic approach to drug safety and to make all stakeholders aware of advances in the technology surrounding drug-induced disease. The technology is available to make major strides in improving the overall management of drug-induced disease. The major barrier to progress is the lack of leadership from any of the powerful sectors involved in drug use.

The treatment of moderate to severe psoriasis with a new anti-CD11a monoclonal antibody

BACKGROUND

Anti-CD11a (hu1124) is a humanized monoclonal antibody directed against the CD11a subunit of LFA-1. This study investigated whether treatment with anti-CD11a antibody provides clinical benefit to patients with moderate to severe plaque psoriasis.

METHODS

This was a double-blind, placebo-controlled, phase II, multicenter study. In total, 145 patients with minimum Psoriasis Area and Severity Index scores of 12 and affected body surface area of 10% or more were sequentially enrolled into low-dose (0.1 mg/kg, n = 22) or high-dose (0.3 mg/kg, n = 75) groups. Within groups, patients were randomized to treatment or placebo (n = 48) in a 2:1 ratio. Drug was administered intravenously at weekly intervals for 8 weeks.

RESULTS

The percentage of subjects achieving more than 50% improvement in physician's global assessment at day 56 (1 week after final dose) was 15% and 48% for placebo and 0.3 mg/kg of drug, respectively (P =.002). A physician's global assessment of excellent (>75% improvement) was greater in the 0.3 mg/kg group versus placebo (25% vs 2%, P =.0003). Average Psoriasis Area and Severity Index scores at day 56 were 13.9 +/- 7.5 (placebo) and 10.9 +/- 8.4 (0.3 mg/kg) (P <.0001). Epidermal thickness was reduced in the 0.3 mg/kg group compared with the placebo group (37% vs 19%, P =.004). Treatment was well tolerated; mild to moderate flu-like complaints were the most common adverse events. White blood cell counts and lymphocyte counts transiently increased. Depletion of circulating lymphocytes did not occur.

CONCLUSIONS

Anti-CD11a antibody administered intravenously in 8 weekly doses of 0.3 mg/kg was well tolerated and induced clinical and histologic improvements in psoriasis.

Should celecoxib be contraindicated in patients who are allergic to sulfonamides? Revisiting the meaning of 'sulfa' allergy

Celecoxib, a selective cyclo-oxygenase-2 inhibitor, is a diaryl-substituted pyrazole derivative containing a sulfonamide substituent. Because of this structural component, celecoxib is contraindicated for use in patients who have demonstrated allergic reactions to sulfonamides. However, there is a lack of data demonstrating cross-reactivity among sulfonamide medications. A sulfonamide is any compound with an SO2NH2 moiety. The major difference between sulfonamide antimicrobials and other sulfonamide-containing medications such as furosemide, thiazide diuretics and celecoxib, is that sulfonamide antimicrobials contain an aromatic amine group at the N4 position. This allows for division of the sulfonamides into 2 groups: aromatic amines (i.e., sulfonamide antimicrobials) and nonaromatic amines. In addition, sulfonamide antimicrobials contain a substituted ring at the N1-position; this group is not found with nonaromatic amine-containing sulfonamides. Adverse reactions to sulfonamide antimicrobials include type I, or immunoglobulin (Ig) E-mediated reactions, hypersensitivity syndrome reactions, and severe skin reactions such as toxic epidermal necrolysis. The aromatic amine portion of the sulfonamide antimicrobial is considered to be critical in the development of latter 2 reactions. In susceptible individuals, the hydroxylamine metabolite is unable to be detoxified leading to a cascade of cytotoxic and immunological events that eventually results in the adverse reaction. Since celecoxib does not contain the aromatic amine, adverse reactions such as hypersensitivity syndrome reactions and toxic epidermal necrolysis would not be expected to occur at the same frequency as they do with sulfonamide antimicrobials. Similarly, for IgE-mediated reactions, the N1-substituent and not the sulphonamide moiety is important in determining specificity to antibodies. Celecoxib and other nonaromatic amine-containing sulfonamide medications do not contain the N1-substituent. Cross-reactivity among the various sulfonamide-containing medications has also not been substantiated by published case reports. In fact, conflicting information exists in the literature. Reports showing lack of cross-reactivity balance the few case reports suggesting cross-reactivity. Cross-reactivity between sulfonamide medications should be based on scientific data, including chemistry, metabolism, immune responses and clinical data. Based on the current information, there is no documentation for cross-reactivity between sulfonamide antimicrobials and other sulfonamide medications, such as celecoxib.

What will be the role of pharmacogenetics in evaluating drug safety and minimising adverse effects?

In the US, adverse drug reactions (ADRs) rank between the fourth to sixth leading cause of death, ahead of pneumonia and diabetes mellitus. An important reason for the high incidence of serious and fatal ADRs is that the existing drug development paradigms do not generate adequate information on the mechanistic sources of marked variability in pharmacokinetics and pharmacodynamics of new therapeutic candidates, precluding treatments from being tailored for individual patients. Pharmacogenetics is the study of the hereditary basis of person-to-person variations in drug response. The focus of pharmacogenetic investigations has traditionally been unusual and extreme drug responses resulting from a single gene effect. The Human Genome Project and recent advancements in molecular genetics now present an unprecedented opportunity to study all genes in the human genome, including genes for drug metabolism, drug targets and postreceptor second messenger machinery, in relation to variability in drug safety and efficacy. In addition to sequence variations in the genome, high throughput and genome-wide transcript profiling for differentially regulated mRNA species before and during drug treatment will serve as important tools to uncover novel mechanisms of drug action. Pharmacogenetic-guided drug discovery and development represent a departure from the conventional approach which markets drugs for broad patient populations, rather than smaller groups of patients in whom drugs may work more optimally. Pharmacogenetics provides a rational framework to minimise the uncertainty in outcome of drug therapy and clinical trials and thereby should significantly reduce the risk of drug toxicity.

The health status of obese individuals in Canada

OBJECTIVE

To determine whether there is a clinically relevant difference in the health state utilities of obese and non-obese individuals as measured by the Health Utility Index Mark III.

METHODS

Secondary analysis of the population-based, cross-sectional, interviewer-administered National Population Health Survey (NPHS), 1996-1997. A probability sample of house-dwelling Canadians, excluding populations on First Nations Reserves, Canadian Armed Forces Bases, the Yukon and Northwest Territories, and long-term residents of hospitals or residential care facilities. The sub-sample used in this analysis consisted of 38 151 respondents (52.4% male) between the ages of 20 and 64 y, excluding pregnant women. Health Utilities Index-Mark III (HUI3) scores were used to define normal weight (body mass index (BMI) 19-24.9 kg/m(2)), overweight (BMI 25-29.9 kg/m(2)), obese (BMI 30-34.9 kg/m(2)), and morbidly obese (BMI> or =35 kg/m(2)) individuals. HUI3 scores were age- and gender-standardized.

RESULTS

The overall prevalence of obesity (BMI> or =30 kg/m(2)) in this Canadian population was 13.3%. The average difference in HUI3 scores between normal weight and morbidly obese respondents was 0.04 (P<0.001). Statistically significant (P<0.05) differences across BMI categories were found in each of the eight component attributes of the HUI3. The attributes with the most substantial difference between normal and obese patients were cognition, mobility and pain. All demonstrated a > or =2-fold increase in the proportion of individuals in poorer classifications of health when normal weight respondents were compared with the morbidly obese. The magnitude of the decrement in utility ratings associated with obesity was comparable with other chronic non-cardiovascular conditions such as migraine or colitis.

CONCLUSION

The results indicate that changes in self-rated health status appear to be due to significant changes across several relevant domain attributes. Obesity has a significant impact on both quality of life and health.

Signaling for ethanol-induced apoptosis and repair in vitro

OBJECTIVES

To evaluate whether caspases are involved in ethanol (EtOH)-induced apoptosis and if polyenylphosphatidylcholine (PPC) affects apoptosis, in vitro in Hep G2 cells.

METHODS

Cells were treated with 100 mmol/L EtOH for 24 h and with 2 doses of 100 mmol/L EtOH (1/24 h) in the presence of absence of 20 mmol/L of PPC or 50 micromol/L caspase 3 inhibitor (IDN). Cells were analyzed for apoptosis by transmission electron microscopy (TEM) 6000 cells/treatment, DNA fragmentation by ELISA and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (T dt-mediated d-UTP) nick-end-labeling, TUNEL.

RESULTS

100 mmol/L dose of EtOH resulted in 22 +/- 2.5% (p < 0.001) apoptosis (vs. control). Two consecutive doses of 100 mmol/L EtOH for 24 h each caused 36 +/- 3.0% (p < 0.001 vs. control and p < 0.05 vs. one dose). PPC significantly reduced apoptosis (vs. non exposed to PPC): 100 mmol/L -12 +/- 1.5% (p < 0.05) and 2 x 10(-)(0) mmol/L -20 +/- 2.0% (p < 0.001). Pretreatment with 50 micromol caspase inhibitor reduced EtOH-induced apoptosis in a similar proportion.

CONCLUSIONS

PPC downregulates EtOH-apoptosis by a mechanism similar to caspase inhibition.

The toxicity of Callilepis laureola, a South African traditional herbal medicine

OBJECTIVES

To review the literature on the toxicity of Callilepis laureola, and to assess the cytotoxicity of C. laureola in human hepatoblastoma Hep G2 cells in vitro.

DESIGN AND METHODS

Cells were incubated for up to 48 h in the presence of increasing concentrations of an aqueous extract of C. laureola (0.3-13.3 mg/mL). Cytotoxicity was quantitated spectrophotometrically by the metabolism of the tetrazolium dye MTT. Cytoviability of the control cells was considered to be 100%.

RESULTS

C. laureola produced cytotoxicity in a concentration-dependent manner. Cytotoxicity was significant at all concentrations tested (0.3-2.5 mg/mL, p < 0.05 vs. controls and 3.3-13.3 mg/mL, p < 0.0001 vs. controls). After 6 h, 100% toxicity was observed at a concentration of 6.7 mg/mL.

CONCLUSION

C. laureola causes significant cytotoxicity in Hep G2 cells in vitro. These findings are in accordance with the observed hepatotoxicity in clinical cases of C. laureola poisoning.

Cytokine network in nonresponding chronic hepatitis C patients with genotype 1: role of triple therapy with interferon alpha, ribavirin, and ursodeoxycholate

OBJECTIVE

(i) to characterize the profile of tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), IL 10, Fas-ligand and transforming growth factor beta (TGF beta), chronic hepatitis C (HCV) patients with genotype 1; (ii) to determine the influence of triple therapy (TT) with interferon alpha (IFN alpha) + ribavirin + ursodeoxycholic acid on these cytokines and (iii) to establish the relationship between the pro-inflammatory cytokines and the outcome of treatment.

DESIGN AND METHODS

22 patients infected with HCV-genotype 1 a/b and non responsive to IFN-alpha monotherapy were enrolled in the TT. The controls were 49 HCV naïve patients with genotype 1 a/b. Cytokine levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The baseline TNF alpha values (pg/mL) in the sustained responders (SRs) (63+/-3) were significantly lower than non-responders (NRs) (140+/-16) (p < 0.001). Baseline Fas (ng/mL) levels were also lower in SRs (4.3+/-0.2) than NRs (5.4+/-0.4) (p < 0.05).

CONCLUSIONS

Fas and TNF alpha may be used as serological markers of inflammation and effectiveness of therapy.

Cytokines as predictors for sustained response and as markers for immunomodulation in patients with chronic hepatitis C

OBJECTIVES

(i) To characterize serum cytokine levels of tumor necrosis factor alpha (TNF alpha), interleukin 6 (IL 6), IL 8 and IL 12 in non-cirrhotic patients with chronic hepatitis C, (ii) to correlate the levels of these cytokines with the degree of the disease at the basal level, (iii) to correlate these levels with the response to therapy, (iv) to compare profiles of cytokines in monotherapy (MT) versus combination therapy (CT), and (v) to compare the immunomodulatory effects of MT versus CT.

DESIGN AND METHODS

47 patients were enrolled in the study. The controls were 120 volunteers (recruited from students and staff) that did not present HCV RNA positive and were not known to suffer any other metabolic disease. Thirty patients formed the other group of controls, with alcoholic liver disease (ALD). Serum cytokine levels were assessed using enzyme-linked immunosorbent assay (ELISA).

RESULTS

The sustained responders (SRs) have basal values much lower than relapsed responders (RRs) and non-responders (NRs) regardless of the therapy.

CONCLUSIONS

Cytokines can be used as non-invasive markers for sustained response and as monitors for the outcome of therapy.

CYP2E1-mediated modulation of valproic acid-induced hepatocytotoxicity

OBJECTIVES

To determine the cytotoxicity of valproic acid (VPA) and its metabolite, 4-ene-valproic acid (4-ene-VPA) in human hepatoblastoma cells (Hep G2), and to study the modulatory effect of cytochrome P450 2E1 induction in this model.

METHODS

Cells were exposed to VPA or 4-ene-VPA in the presence of either ethanol (EtOH), or EtOH combined with disulphiram (DS). Some cells were exposed to alpha-fluoro-VPA or to alpha-fluoro-4-ene-VPA in the absence of CYP2E1 inducers. Apoptosis and necrosis were measured by analyzing 6000 cells per sample using transmission electron microscopy, while cytokine release and apoptosis were quantitated by ELISA.

RESULTS

VPA + EtOH increased VPA cytotoxicity. 4-ene-VPA + EtOH significantly increased toxicity, while DS + EtOH significantly reduced this toxicity. Alpha-fluorinated analogues reduced cytotoxicity compared to the corresponding VPA compounds. Neither VPA nor alpha-fluorinated VPA increased the release of IL-6 or TNF-alpha in media. A significant increase in the release of TNF-alpha was observed in cells exposed to 4-ene-VPA that further increased with EtOH exposure.

CONCLUSIONS

Cells exposed to 4-ene-VPA experience greater cytotoxicity than those treated with VPA. Cytochrome P450 2E1 inducers enhance toxicity in VPA-exposed cells, while alpha-fluorination of VPA diminishes cytotoxicity by directly interfering with the beta-oxidation of the 4-ene-VPA metabolite.

Mechanisms of alcoholic liver disease: cytokines

This article represents the proceedings of a workshop at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Manuela G. Neuman. The presentations were (1) New aspects of hepatic fibrosis, by D. A. Brenner; (2) Cellular immune response in hepatitis C models, by B. Rehermann; (3) The role of interleukin-10 in acute alcoholic hepatitis, by J. Taieb, S. Chollet-Martin, M. Cohard, J. J. Garaud, and T. Poynard; (4) Cytokine-mediated apoptosis in vitro, by M. G. Neuman; (5) Signaling for apoptosis and repair in vitro, by G. G. Katz, R. G. Cameron, N. H. Shear, and M. G. Neuman; (6) Interferons activate the P42/44 mitogen-activated protein kinase and Janus Kinase signal transducers and activation of transcription (JAK-STAT) signaling pathways in hepatocytes: Differential regulation by acute ethanol via a protein kinase C-dependent mechanism, by B. Gao; (7) Genetic polymorphisms of interleukin-1 in association with the development of Japanese alcoholic liver disease, by M. Takamatsu, M. Yamauchi, M. Ohata, S. Saito, S. Maeyama, T. Uchikoshi, and G. Toda; and (8) Increased levels of macrophage migration inhibitory factor in sera from patients with alcoholic liver diseases, by T. Kumagi, S. M. F. Akbar, M. Abe, K. Michitaka, N. Horiike, and M. Onji.

Reporting of fatal adverse drug reactions

OBJECTIVES

To review the reports of fatal adverse drug reactions (ADRs) submitted to the Ontario Medical Association Adverse Drug Reactions Monitoring Program between 1990 and 1994; to identify drugs associated with fatal outcomes; and to assess the causative role of the drug in these events and the completeness of the data in these reports.

METHODS

Drug(s) identified on each ADR report as being responsible for the reaction were considered. Agents were classified by the Anatomical Therapeutic and Chemical classification system. The causality of each ADR report was evaluated by using an algorithmic rating scale.

RESULTS

From the Ontario Medical Association database, 97 cases of ADRs that resulted in death were reviewed. One hundred fourteen medications were implicated as "suspect" drugs in the 97 deaths. The most commonly implicated drug classes were musculoskeletal agents, blood and blood-forming organ agents, and nervous system agents. Patients over 65 years of age comprised 60% of this series. After independent assessment as to causality, 13% of the cases were rated as probable, 86% were rated as possible and 1% were rated as doubtful. Seventy per cent of reports did not include information regarding medical history. Forty-two per cent of cases failed to provide adequate information to evaluate the feasibility of the time to onset of the ADR. The use of concomitant drugs was not reported in 12% of cases.

CONCLUSIONS

The drugs most frequently implicated in fatal ADRs were consistent with those reported in other studies. Algorithmic causality assessments were of limited value in these reports. The completeness of the reports and adequacy of the information were poor. The type of reporting forms and information provided were not homogenous. There is a need to improve quality of reporting and harmonize reporting forms between monitoring bodies. The feasibility of unique data collection forms and obligatory reporting for fatal ADRs should be considered.

Idiosyncratic drug reactions: the reactive metabolite syndromes

Idiosyncratic drug reactions are unpredictable reactions that can result in significant morbidity and mortality. Severe reactions are often characterised by fever and internal organ involvement. Despite progress in the identification of reactive metabolites believed to be the cause of idiosyncratic reactions, the basic mechanisms remain elusive. Furthermore, because of the lack of consensus regarding definition of these syndromes, reporting, and therefore epidemiological data, are often unreliable. Research is needed to explore further the pathophysiology of these reactions, so that better diagnostic tests and treatment methods can be developed.

A novel lymphocyte toxicity assay to assess drug hypersensitivity syndromes

OBJECTIVES

To validate the novel lymphocyte toxicity assay (LTA) based on the mitochondrial succinate dehydrogenase (SDH) activity vs. the LTA by using trypan blue exclusion and to determine the utility of the assay to confirm drug hypersensitivity syndrome (DHS) to sulphonamides (SMX) and aromatic anticonvulsants.

METHODS

Incubation of patient lymphocytes, with or without murine hepatic microsomes with anticonvulsants or SMX. The viability of lymphocytes was based on SDH activity that can be measured spectrophotometrically. The percentage of cells displaying cytotoxicity compared to controls (cells treated only with drug) was calculated. Seventy-two immunocompetent and 16 immunocompromised (HIV) patients with DHS to SMX were sampled. The results were validated vs. 26 controls that had not experienced DHS to SMX. Sixty-two patients who had DHS to anticonvulsants were compared with 24 controls that did not have any DHS to the same anticonvulsants.

RESULTS

The results showed a very good percentage of sensitivity 98 and specificity 96 with a kappa-score of 0.96. LTA higher than 13.5% was considered positive for the immunocompetent population and LTA higher than 22% was positive for the immunocompromised population. In two of the 26 controls, LTA was positive.

CONCLUSION

The high quantitative kappa-value 0.96 emphasizes that the novel LTA is at least as good as the trypan blue assay. The latter is labor intensive, time consuming, and prone to human error. The new assay is objective, faster, and has been reproducible in assessing cytotoxicity.