Translating instruments into multiple Mayan languages for a hypertension T4 study in Guatemala

Issue

Guatemala is a culturally and linguistically diverse country. Mayan languages are primarily spoken languages; few people know their written form. Health features and outcomes are difficult to assess due to the lack of validated instruments in these languages.

Description of the Problem

A cluster randomized trial to improve hypertension control is being conducted in 36 municipalities where Mayan languages are spoken in addition to Spanish. Instruments for measuring study outcomes were developed in Spanish and cross-culturally adapted into five Mayan languages following WHO's methodology. First, data were gathered on the proportion of people only fluent in a Mayan language in each district. We prioritized those Mayan languages spoken by more than 20% of the non-Spanish speaking population: Achí, K'iche', Kaqchikel, Tz'utujil and Mam. Second, forward translation to the Mayan languages was conducted by a local healthcare professional, who verbally recorded each instrument. The study team identified key words and concepts to guarantee content equivalence. Third, back-translation was conducted by two independent healthcare providers, who were blinded to the original instruments. The research team formally compared the original questionnaires with the back-translated versions to ensure they were conceptually equivalent and culturally adapted. Discrepancies were corrected as needed. Finally, local interviewers were trained on how to accurately use the written Spanish questionnaires and the Mayan language verbal recordings.

Results

By following this methodology, we achieved cross-culturally adapted instruments to improve the information-gathering process in communities where only Mayan languages are spoken.

Lessons

Having culturally adapted tools will allow researchers to reach a broader range of the target population, obtain more accurate information, and take into account participants' culture and cosmovision.

Key messages

Translating questionnaires to people’s native language allows researchers to obtain more accurate information in a standardized way and better understand participants’ culture and cosmovision. The described methodology is beneficial for conducting research in linguistically diverse countries. It promotes effective and inclusive communication among researchers and participants.

Cytokine release assays: current practices and future directions

As a result of the CD28 superagonist biotherapeutic monoclonal antibody (TGN 1412) "cytokine storm" incident, cytokine release assays (CRA) have become hazard identification and prospective risk assessment tools for screening novel biotherapeutics directed against targets having a potential risk for eliciting adverse pro-inflammatory clinical infusion reactions. Different laboratories may have different strategies, assay formats, and approaches to the reporting, interpretation, and use of data for either decision making or risk assessment. Additionally, many independent contract research organizations (CROs), academic and government laboratories are involved in some aspect of CRA work. As a result, while some pharmaceutical companies are providing CRA data as part of the regulatory submissions when necessary, technical and regulatory practices are still evolving to provide data predictive of cytokine release in humans and that are relevant to safety. This manuscript provides an overview of different approaches employed by the pharmaceutical industry and CROs, for the use and application of CRA based upon a survey and post survey follow up conducted by ILSI-Health and Environmental Sciences Institute (HESI) Immunotoxicology Committee CRA Working Group. Also discussed is ongoing research in the academic sector, the regulatory environment, current limitations of the assays, and future directions and recommendations for cytokine release assays.

[Domino transplantation of a living-donor kidney graft affected by thrombotic microangiopathy: surgical aspects]

We report surgical aspects of the first case of retransplantation of a kidney initially retrieved from a cadaveric donor, then on a first recipient which developed a recurrent severe and intractable thrombotic microangiopathy on the allograft.

One dose of a porcine circovirus 2 (PCV2) sub-unit vaccine administered to 3-week-old conventional piglets elicits cell-mediated immunity and significantly reduces PCV2 viremia in an experimental model

The immunogenicity and efficacy generated by one dose of a PCV2 sub-unit vaccine (Porcilis PCV) were evaluated in 3-week-old conventional piglets. Vaccination induced both humoral and cell-mediated responses against PCV2, which were increased after the challenge with a PCV2 genotype "b" isolate. High levels of maternally derived antibodies (IPMA >or= 10 log(2)) at the time of vaccination were found to interfere with the active seroconversion, whereas titres below 8 log(2) allowed the development of a proper antibody response. Nevertheless, the immunity induced by one dose of the product was partly protective against PCV2 infection, since viremia, shedding and viral load in tissues were significantly reduced in vaccinated pigs compared to controls.

Lack of transmission of porcine circovirus type 2 to weanling pigs by feeding them spray-dried porcine plasma

An experiment was conducted to determine whether spray-dried porcine plasma containing 2.47 x 10(5) dna copies of porcine circovirus type 2 (pcv-2) could infect weanling pigs when fed to them. Five specific pathogen-free (spf) weanling pigs were fed ad libitum for 45 days a control diet and six pigs were fed a test diet containing 8 kg sdpp per 100 kg feed. The two groups were housed in separate biosecurity level-3 rooms. None of the pigs in either group developed any clinical signs or became pcv-2 viraemic or seroconverted.

Porcine circovirus type 2 (PCV2) vaccination of conventional pigs prevents viremia against PCV2 isolates of different genotypes and geographic origins

The efficacy of recently developed porcine circovirus type 2 (PCV2) vaccines has not been tested yet against PCV2 isolates of the two proposed genotypes. In the present work, the efficacy of a subunit vaccine containing PCV2 capsid protein was evaluated by using a challenge model with four different PCV2 isolates of different genotype and geographic origin. The vaccine prevented the development of viremia in all cases as well as significantly decreased nasal and faecal shedding of the virus. Also, the vaccine elicited PCV2-specific neutralizing antibodies to PCV2 even in the presence of maternally derived immunity.

A Third Renal Transplantation: Is It Relevant and Is It Worth It?

INTRODUCTION

The aim of this retrospective study was to determine the outcome of third cadaveric renal transplantations performed between 1989 and 2004 among a cohort of 35 patients whose immunosuppression included induction therapy and calcineurin inhibitors. Most patients were highly sensitized with 1 (0-4) HLA (classes I + II) incompatibility between donor and recipient.

RESULTS

The median follow-up time was 57 months (range, 1-190). Fourteen patients experienced delayed graft function that required posttransplantation hemodialysis. The current patient and graft survival rates were 91.4% and 82.8%, respectively. At last follow-up, 6 grafts had been lost: 1 due to primary nonfunction; 1 due to an urinary leak (day 45); 2 deaths with functioning grafts; and 2 chronic allograft nephropathies (CAN) at 85 and 60 months posttransplantation, respectively. Among the 10 patients who experienced acute rejection episodes, half were steroid-sensitive, whereas the others required OKT3 therapy. Overall, when excluding the 2 patients who presented with early loss of their grafts, 13 of 33 patients (39.4%) developed CAN, which led to the graft loss in only 2 cases. The mean creatinine clearance was 57 +/- 23 mL/min at year 5. Of the 35 recipients, 12 (34.3%) developed graft/perigraft complications, among whom 10 (83.3%) required treatment. The most frequent complication was lymphocele (M = 4; 11.4%) or infections that led to rehospitalization (n = 17).

CONCLUSION

Results from third transplantations were encouraging. Thus, despite the organ shortage, a third graft was worth it!

Evaluation of the microbial safety of a new 1.5 l enteral feeding diet reservoir system

BACKGROUND & AIMS

Microbial safety is essential during enteral nutrition (EN) as it can be the origin of gastrointestinal symptoms, but can also lead to systemic infections. The use of large-volume diet reservoirs could limit the risk of contamination and reduce nursing time, due to fewer repeated manipulations. The aim of the study was to evaluate in vivo the microbial safety of a new 1.5l enteral feeding diet reservoir system.

METHODS

After validation of the study settings under standard laboratory conditions, 86 EN lines with sealed fittings were connected to 1.5l diet reservoirs under hospital/patient conditions. Microbial identification and quantification at different sampling times and points were performed.

RESULTS AND CONCLUSIONS

No microbial contamination was observed in the diet reservoirs and in the nutrition lines above the drip chamber, demonstrating the microbial safety of this system. Retrograde contamination of the distal nutrition line end at completion of EN was observed and may be affected by the cumulative time of use of the tube. The contaminating microbial species were essentially bacteria of normal oral and digestive flora.

[Association between the A2 allele of the HLA system and age at onset of Alzheimer's disease]

OBJECTIVE

Alzheimer is a multifactor disease occurring in a sensitive genetic territory. The e4 allele of the apolipoprotein E (APO E) is a recognised factor of risk. Some studies have suggested an association between the A2 allele of the HLA system and an earlier onset of the disease notably when it appears before the age of 64 or after the age of 75. The aim of our study was to explore this hypothesis in an independent sample of patients.

METHODS

We compared the influence of the A2 allele of the HLA system on the age at onset of the disease in two groups of Caucasian patients presenting with Alzheimer's disease: early onset if the disease appeared before the age of 60 (n= 31) and late onset if it had appeared after the age of 75 (n= 44). The influence of the e4 allele of APO E was also taken into account.

RESULTS

The comparison of the patients depending on the presence or not of at least one HLA-A2 allele revealed no significant difference, whatever the group of patients studied, in the age at onset of the disease.

CONCLUSION

The age at onset of Alzheimer's disease was not influenced in our study by the presence of the HLA-A2 allele.

IL-4 exacerbates disease in a Th1 cell transfer model of colitis

IL-4 is associated with Th2-type immune responses and can either inhibit or, in some cases, promote Th1-type responses. We tested the effect of IL-4 treatment on the development of inflammation in the CD4(+)CD45RB(high) T cell transfer model of colitis, which has been characterized as a Th1-dependent disease. IL-4 treatment significantly accelerated the development of colitis in immunodeficient recipients (recombinase-activating gene-2 (Rag2)(-/-)) of CD4(+)CD45RB(high) T cells. Quantitative analysis of mRNA expression in the colons of IL-4-treated mice showed an up-regulation of both Th1- and Th2-associated molecules, including IFN-gamma, IP-10, MIG, CXCR3, chemokine receptor-8, and IL-4. However, cotreatment with either IL-10 or anti-IL-12 mAb effectively blocked the development of colitis in the presence of exogenous IL-4. These data indicate that IL-4 treatment exacerbates a Th1-mediated disease rather than induces Th2-mediated inflammation. As other cell types besides T cells express the receptor for IL-4, the proinflammatory effects of IL-4 on host cells in Rag2(-/-) recipients were assessed. IL-4 treatment was able to moderately exacerbate colitis in Rag2(-/-) mice that were reconstituted with IL-4Ralpha-deficient (IL-4Ralpha(-/-)) CD4(+)CD45RB(high) T cells, suggesting that the IL-4 has proinflammatory effects on both non-T and T cells in this model. IL-4 did not cause colitis in Rag2(-/-) mice in the absence of T cells, but did induce an increase in MHC class II expression in the lamina propria of the colon, which was blocked by cotreatment with IL-10. Together these results indicate that IL-4 can indirectly promote Th1-type inflammation in the CD4(+)CD45RB(high) T cell transfer model of colitis.

Identification of six novel polymorphisms in the human corneodesmosin gene

Psoriatic epidermis is characterised by a defective differentiation program leading to an abnormal permeability barrier and impaired desquamation. The corneodesmosin gene (CDSN) or "S" gene is a strong candidate in psoriasis susceptibility, due first to its genomic position ("S" gene, 160 kb telomeric to HLA-C) and second to its expression and function in the epidermis. Moreover, an association between CDSN and psoriasis vulgaris was recently shown in Caucasian populations. In order to pursue the CDSN polymorphism analysis, we determined the sequence of its alleles in 14 HLA-Cw6-positive individuals. A 4.6 kb genomic fragment encompassing the first exon, the unique intron and the coding sequence of the second exon was amplified from 8 psoriatic patients and 6 controls. Allelic discrimination was performed by restriction fragment length polymorphism analysis. The entire coding sequence and the intron boundaries of 27 alleles were sequenced. A total of 26 dimorphic sites were found, 23 consisting in single nucleotide polymorphisms (SNPs) and 3 in triplet modifications. Five out of the 23 SNPs have not been previously reported, and among them, one causes amino-acid exchange leading to the suppression of a potential chymotrypsin site. Among the triplet modifications, one leads to deletion of one out of five consecutive valines in the protein. The high polymorphism of the gene allowed the identification of 13 different alleles. These haplotypes will permit additional family-based studies that could provide new genetic support for the involvement of CDSN in psoriasis susceptibility. Moreover, the establishment of an extensive catalogue of CDSN alleles will allow functional analyses of the different protein isoforms.

Study of host- and virus-related factors associated with spontaneous hepatitis C virus clearance

Epidemiologic parameters, virologic characteristics and frequency of HLA class II DR and DQ antigens were compared between 63 subjects with spontaneous hepatitis C virus clearance (group 1) and 282 patients with chronic active hepatitis C virus infection (group 2). DRB1*1101 and moreover DQB1*0301 alleles were more frequent in group 1 than in group 2 (33.8% vs. 14.7% and 64.4% vs. 28.6%; P=0.012 and P=0.003, respectively). The frequency of DQB1*02 was lower in group 1 than in group 2 (25.4% vs. 49%; P=0.04). No difference was observed in viral genotype distribution between group 1 and group 2. Univariate analysis showed that female sex and contamination by intravenous drug use were associated with self limited infection. However, by multivariate analysis, the only independent factor associated with hepatitis C virus RNA clearance was female sex (P=0.004). In conclusion, spontaneous hepatitis C virus RNA clearance is determined by class II antigens (mainly DQB1*0301) and female sex, while viral genotype plays no role.

Use of Brucella abortus vaccine strain RB51 in pregnant cows after calfhood vaccination with strain 19 in Argentina

One hundred and seven pregnant cows, which had been calfhood vaccinated with Brucella abortus strain 19 (S-19) were revaccinated with either S-19 or strain RB51 (S-RB51). All S-19-revaccinated animals seroconverted, while none of the RB51-revaccinated animals seroconverted. Two out of 25 (8%) S-19-revaccinated animals aborted, while none of the 57 RB51-revaccinated group aborted. Four of the S-19-revaccinated animals shed S-19 in the milk for at least 7 days, while only 1 cow shed S-RB51 for at least 3 days (but <7 days) post-parturition. Revaccination of strain 19 calfhood-vaccinated, pregnant cattle with S-RB51 appears to be a safe procedure with no diagnostically negative consequences.

IL-10 is required for prevention of necrosis in the small intestine and mortality in both genetically resistant BALB/c and susceptible C57BL/6 mice following peroral infection with Toxoplasma gondii

The role for IL-10 in the immunopathogenesis of acute toxoplasmosis following peroral infection was examined in both genetically susceptible C57BL/6 and resistant BALB/c mice. C57BL/6-background IL-10-targeted mutant (IL-10-/-) mice all died in 2 wk after infection with 20 cysts of the ME49 strain, whereas only 20% of control mice succumbed. Histological studies revealed necrosis in the small and large intestines and livers of infected IL-10-/- mice. The necrosis in the small intestine was the most severe pathologic response and was not observed in control mice. Treatment of infected IL-10-/- mice with either anti-CD4 or anti-IFN-gamma mAb prevented intestinal pathology and significantly prolonged time to death. Treatment of these animals with anti-IL-12 mAb also prevented the pathology. Significantly greater amounts of IFN-gamma mRNA were detected in the lamina propria lymphocytes obtained from the small intestine of infected IL-10-/- mice than those from infected control mice. In common with C57BL/6-background IL-10-/- mice, BALB/c-background IL-10-/- mice all died developing intestinal pathology after infection. Control BALB/c mice all survived even after infection with 100 cysts and did not develop the intestinal lesions. Treatment with anti-IFN-gamma mAb prevented the pathology and prolonged time to death of the infected IL-10-/- mice. These results strongly suggest that IL-10 plays a critical role in down-regulating IFN-gamma production in the small intestine following sublethal peroral infection with Toxoplasma gondii and that this down-regulatory effect of IL-10 is required for prevention of development of IFN-gamma-mediated intestinal pathology and mortality in both genetically resistant BALB/c and susceptible C57BL/6 mice.

Pharmacology of cizolirtine: a new analgesic agent

Cizolirtine citrate (E-4018) is a new analgesic agent with antinociceptive activity against phenylquinone (ED50 33.7 mg/kg) and acetic acid (ED50 24.4 mg/kg) in mice, against acetic acid in rats (ED50 21.3 mg/kg) and in the plantar test (ED50 26.8 mg/kg). It demonstrated antinociceptive activity in the tail-pinch and tail-flick tests (ED50s of 68.0 and 46.0 mg/kg, respectively), in both phases of the formalin test (ED50 13.8 and 2.31 mg/kg), and in the capsaicin test (ED50 7.14 mg/kg). Cizolirtine does not inhibit prostaglandin biosynthesis, it is not a ligand for opioid receptors, it does not have antiinflammatory or ulcerogenic activity, it has some antipyretic activity and shows no affinity for alpha 2-adrenergic receptors, but its analgesic effect was modified by idazoxan and by desipramine. Recent studies have shown that the analgesic effect of cizolirtine could be related, at least partially, to an inhibition of spinal substance P release.

Study of the association between major histocompatibility complex class II genes and the response to interferon alpha in patients with chronic hepatitis C infection

OBJECTIVE

The aim of the study was to determine the influence of HLA class II genes on the response to interferon-alpha (IFN-alpha) in patients with chronic hepatitis C.

METHODS

The distribution of HLA DRB1 and DQB1 alleles was assessed in 170 caucasoïd patients treated with IFN-alpha for chronic hepatitis C. 50 patients had a long term sustained response to treatment whereas 120 patients were nonresponders.

RESULTS

Female sex, non-1 HCV genotype particularly genotype 2 and pretreatment low serum HCV RNA level were associated with long-term sustained response to IFN-alpha. A trend towards a higher prevalence of DRB1*07 allele in non responders than in patients with sustained response (45% vs. 28%, odds ratio 2.1; P < 0.05) on the one hand and of DQB1*06 allele in HCV genotype 1 patients with sustained response than in HCV genotype 1 nonresponders (75% vs 27.3%, odds ration 7.9; P < 0.02) on the other hand, were observed. However, none of these two differences remained significant after Bonferroni's correction.

CONCLUSION

Accordingly, we conclude that the response to IFN-alpha therapy is more tightly related to virus factors than to host's HLA class II genes.

MHC class II gene associations with autoantibodies to U1A and SmD1 proteins

Autoantibodies against U small nuclear ribonucleoproteins (snRNP) are frequently present in the serum of patients with systemic rheumatic diseases, and have been reported to be associated with HLA-DR and -DQ genes. To better define the role of HLA genes in the production of such antibodies, we studied immunogenetic associations with autoantibodies reacting with U1 RNP, U1A and SmD1 proteins, and synthetic peptides containing immunodominant linear epitopes of these proteins. Only two out of the 15 overlapping peptides of U1A (i.e. peptides 35-58 and 257-282) and three of 11 peptides of SmD1 (i.e. peptides 1-20, 44-67 and 97-119) were significantly recognized by patients' sera selected on the basis of their antibody positivity with RNP in immunodiffusion. The distribution of DRB1, DQB1 and DPB1 alleles among the anti-RNP antibody-positive patients (n = 28) and healthy control subjects was similar. Antibodies against U1A (tested in Western immunoblotting with HeLa cell extracts) were positively associated to DRB1*06 allele; antibodies reacting with SmD1 peptide 44-67 were negatively associated to DRB1*02 and DQB1*0602 alleles. No association was found between DPB1 alleles and antibodies reacting with U1A and SmD1 antigens. This first study reporting an association between autoantibodies reacting with U1A and SmD1 proteins (and peptides of these proteins), and immunogenetic markers suggest that the production of antibody subsets directed against different components (or regions of these proteins) bound to the same snRNP particle is associated with distinct MHC class II alleles.

IL-7 deficiency prevents development of a non-T cell non-B cell-mediated colitis

IL-7 is a stromal cell-derived cytokine with a well-established physiologic role in lymphocyte biology. This report describes an unexpected role for IL-7 in the development of colitis in a T and B cell-deficient environment. Recombination-activating gene-2 (RAG-2)-deficient mice (RAG-2(-/-)) were exposed to and subsequently maintained a horizontally transmitted microbial flora that included Helicobacter hepaticus. These animals mounted a strong myeloid cell response and developed both systemic and local signs of a severe colitis. A striking infiltration of F4/80 and MHC class II-positive cells was seen in the colon and cecum of animals undergoing the disease. Mice mutant for both IL-7 and RAG-2 (IL-7/RAG-2(-/-)) that were colonized by the same flora showed no signs of myeloid responses or colitis, indicating that IL-7 plays a critical role in exacerbating a non-T cell/non-B cell-mediated chronic inflammatory response. Recombinant IL-10 protein therapy was able to prevent the occurrence of colitis in susceptible mice, suggesting a pivotal role for macrophages. The implications of a role for IL-7 in this disease model with respect to human inflammatory bowel disease are discussed.

Relation between HLA DRB1 alleles and corticosteroid resistance in giant cell arteritis

OBJECTIVE

To evaluate the clinical usefulness of genomic HLA typing during the first two years of established giant cell arteritis (GCA).

METHODS

HLA typing was performed by PCR-SSO in 41 selected white patients with GCA confirmed by biopsy. Patient data were compared with those of a control group of 384 bone marrow donors (relative risk, p value and chi 2 test for each allele). Clinical features at onset and response to treatment over a two year period were evaluated in relation to the genetic pattern.

RESULTS

DRB1*04 was significantly increased in the GCA group (frequency of 48.78% compared with 19.79% in controls, p < 0.001). The distribution of the DRB1*04 subtypes in the GCA group was similar to that in controls. No clinical or biological differences were found in association with HLA at the time of diagnosis. Over the two year follow up, nine patients presented resistance to corticosteroid treatment and eight of these (88.88%) had DRB1*04 (p < 0.001).

CONCLUSIONS

GCA seems to be associated with HLA DRB1*04 (regardless of the subtype) and this association appears to be accompanied by corticosteroid resistance, suggesting that genomic typing may be useful to identify patients eligible for early alternative treatment to corticosteroid drugs.

HLA class II allele and haplotype frequencies in Ethiopian Amhara and Oromo populations

HLA class II alleles were identified in 181 healthy unrelated Ethiopian children of both sexes and in 350 European controls from the South of France. The Ethiopian individuals belonged to the two major ethnic groups of the country: Oromo (N=83) and Amhara (N=98). In both panels, genetic polymorphism of HLA class II alleles was analysed for the first time by molecular typing of DRB1, DQA1 and DQB1 loci. Allelic and phenotypic frequencies were compared with those of European controls and other African populations. Construction of HLA class II three-locus haplotypes was also performed. The study revealed some differences between the two groups. Characteristic features of Central and North African populations appeared on the Ethiopian HLA genotypes. Surprisingly, DRB1*11 presented one of the lowest gene frequencies in both Ethiopian ethnic groups in contrast to Europeans and West Africans. Furthermore, this decrease was more marked than those observed using serological techniques in other geographically close East African countries. Oromo and Amhara only showed minor differences in spite of their different origins and histories. One significant difference consisted of a lower DRB1*01 gene frequency in Oromo as reported in most West African people. Some new or rare haplotypes were also observed in the Oromo group. Our results underline the distinctive features of the Ethiopian populations among the few HLA genotyping data available for East African groups and emphasise the major interest of such investigations in this region of Africa.

General pharmacological profile and effects of E-4716, a novel histamine receptor blocker, on the central nervous system

The general pharmacological profile and effects of E-4716 on the CNS have been investigated in comparison with other histamine receptor blockers. In in vitro studies with isolated organs and in binding studies on numerous receptors, E-4716 had no activity even at high concentrations, except for the selective blockade of H1 receptors. No activity was observed in pharmacological trials in vivo, such as the Irwin test or analgesia induced by phenylbenzoquinone or electroshock, suggesting a depressant activity on the CNS. In tests potentiating hypnosis induced by barbiturates, benzodiazepines and ethanol in mice, E-4716 always showed milder potentiating effects than the other reference drugs. In monkeys, no sedating effects were observed at 200 mg/kg, p.o. These results suggest that E-4716 exhibits good clinical efficacy without any secondary effects.

Absence of imprinting of HLA class Ia genes leads to co-expression of biparental alleles on term human trophoblast cells upon IFN-gamma induction

Human trophoblast cells have developed various efficient regulatory mechanisms to prevent cell surface expression of the classical HLA-A, -B, and (but not always) -C class I molecules. This allows them to escape maternal alloimmune attack during pregnancy. However, recent results have demonstrated that such a lack of expression could be reversed in villous cytotrophoblast cells purified from term placenta by in vitro IFN-gamma treatment. In this context, we investigated whether both maternal and paternal HLA class Ia antigens were co-dominantly expressed in such trophoblast cells. Using polymerase chain reaction sequence-specific primers for HLA-A and HLA-C alleles, we detected transcripts of both paternal and maternal origins, showing that these genes were not affected by genomic imprinting, at least in term placenta. After in vitro IFN-gamma treatment, the polymorphic HLA-A and HLA-B antigens of both parental origins become detectable at the cell surface, as assessed by flow cytometry and/or complement-dependent microtoxicity test. Appearance of paternal antigens on trophoblast cells upon IFN-gamma induction raises the question of the in vivo biological consequences of this phenomena, in term of materno-fetal tolerance and in particular of a potential allogeneic cytotoxic immune response.

Genes of the major histocompatibility complex class II influence the outcome of hepatitis C virus infection

BACKGROUND & AIMS

The host's immune response may influence the course of hepatitis C virus (HCV) infection. The aim of this study was to investigate the distribution of HLA class II alleles in white subjects who spontaneously recovered from HCV infection compared with that in patients with persistent infection.

METHODS

HLA-DRB1 and -DQB1 typing were performed in 103 consecutive patients with persistent HCV infection (HCV antibody positive, HCV RNA positive) and in 25 subjects with transient HCV infection (HCV antibody positive, persistently negative HCV RNA).

RESULTS

No significant differences between subjects with transient or persistent infection were observed for age, sex, source of infection, or HCV serotype. The frequency of DQB1*0301 and DRB1*1101 alleles was higher in patients with transient infection than in those with persistent infection (84% vs. 30.8%, 40% vs. 9.8%; P < 0.01 and P < 0.02, respectively [Bonferroni correction]). DRB1 and DQB1 alleles did not influence viral load as an independent factor. Mean Knodell's scores were lower in patients with DQB1*0301 allele (6.12 +/- 0.4) than in those negative for DQB1*0301 (7.37 +/- 0.3; P < 0.05).

CONCLUSIONS

Our results suggest that host- rather than virus-related factors are probably involved in the spontaneous clearance of HCV.

Role of interleukin-10 in regulation of T-cell-dependent and T-cell-independent mechanisms of resistance to Toxoplasma gondii

Interleukin-10 (IL-10) is a cytokine which can inhibit T-cell and natural killer (NK) cell functions associated with cell-mediated immunity to intracellular infections. The production of IL-10 by mice infected with Toxoplasma gondii has been implicated in the suppression of lymphocyte proliferation observed during acute toxoplasmosis, as well as susceptibility to infection with this parasite. We have used C57BL/6 mice which lack a functional IL-10 gene (IL-10(-/-) mice) to investigate the role of IL-10 in acute toxoplasmosis. Intraperitoneal infection of IL-10(-/-) mice with T. gondii resulted in 100% mortality by day 13, whereas wild-type C57BL/6 (WT) mice survived acute infection. IL-10(-/-) mice infected with T. gondii had significantly higher serum levels of IL-12 and gamma interferon (IFN-gamma) than WT mice. Early mortality of infected IL-10(-/-) mice was prevented by treatment with IL-10 and significantly delayed by neutralizing antibodies to IL-12 and IFN-gamma. Further studies revealed that SCID/IL-10(-/-) mice infected with T. gondii had delayed time to death compared to IL-10(-/-) mice, indicating that lymphocytes contributed to death of IL-10(-/-) mice. In addition, infected SCID/IL-10(-/-) mice survived longer than infected SCID mice. These latter data indicate that in mice lacking lymphocytes, endogenous IL-10 is associated with increased susceptibility to T. gondii. However, the lack of IL-10 does not alter the infection-induced suppression of T cell and NK cell functions. Our experiments reveal that IL-10 is associated with protection or increased susceptibility to infection with T. gondii, depending on whether mice possess lymphocytes, and demonstrate the important roles of IL-12 and IFN-gamma in the early infection-induced mortality observed in the IL-10(-/-) mice.

IL-10 is required to prevent immune hyperactivity during infection with Trypanosoma cruzi

Previous studies have associated the production of IL-10 with suppression of the protective cell-mediated immune response to Trypanosoma cruzi. To further understand the role of IL-10 in the resistance to and pathogenesis of Chagas' disease, we infected C57BL/6 wild-type (IL-10 +/+) or C57BL/6 IL-10 knockout (IL-10 -/-) mice with the virulent Tulahuen strain of T. cruzi. IL-10 -/- mice had a lower parasite burden and higher levels of serum TNF-alpha, IL-12, and IFN-gamma compared with infected IL-10 +/+ mice. However, infection resulted in earlier mortality of IL-10 -/- mice compared with IL-10 +/+ controls. The earlier mortality of IL-10 -/- mice could be reversed by administering rIL-10 or a neutralizing Ab specific for IL-12. A role for T cells in the early mortality of IL-10 -/- mice was suggested by experiments in which SCID IL-10 -/- mice infected with T. cruzi had a delay in time to death and significantly lower serum levels of IFN-gamma compared with IL-10 -/- mice. Furthermore, treatment of infected IL-10 -/- mice with a mAb specific for CD4 resulted in reduced serum levels of IFN-gamma and a delay in time to death. Altogether, our results demonstrate for the first time that during infection with T. cruzi there is a critical requirement for IL-10 to prevent the development of a pathologic immune response associated with CD4+ T cells and overproduction of IL-12.

IL-10 is required to prevent immune hyperactivity during infection with Trypanosoma cruzi

Previous studies have associated the production of IL-10 with suppression of the protective cell-mediated immune response to Trypanosoma cruzi. To further understand the role of IL-10 in the resistance to and pathogenesis of Chagas' disease, we infected C57BL/6 wild-type (IL-10 +/+) or C57BL/6 IL-10 knockout (IL-10 -/-) mice with the virulent Tulahuen strain of T. cruzi. IL-10 -/- mice had a lower parasite burden and higher levels of serum TNF-alpha, IL-12, and IFN-gamma compared with infected IL-10 +/+ mice. However, infection resulted in earlier mortality of IL-10 -/- mice compared with IL-10 +/+ controls. The earlier mortality of IL-10 -/- mice could be reversed by administering rIL-10 or a neutralizing Ab specific for IL-12. A role for T cells in the early mortality of IL-10 -/- mice was suggested by experiments in which SCID IL-10 -/- mice infected with T. cruzi had a delay in time to death and significantly lower serum levels of IFN-gamma compared with IL-10 -/- mice. Furthermore, treatment of infected IL-10 -/- mice with a mAb specific for CD4 resulted in reduced serum levels of IFN-gamma and a delay in time to death. Altogether, our results demonstrate for the first time that during infection with T. cruzi there is a critical requirement for IL-10 to prevent the development of a pathologic immune response associated with CD4+ T cells and overproduction of IL-12.

Effects of E-4716, a new antihistaminic with antiallergic properties, on chemical mediators induction of immunologic reactions

The effects of E-4716 on chemical mediators were compared with those of classical antihistaminics and other second generation (nonsedating) drugs normally used in the therapy of allergic reactions, such as astemizole, terfenadine and ebastine, in a series of in vitro and in vivo tests. In vitro, antihistaminic activity was demonstrated in a test on isolated organs and a binding test on histamine receptors, with no anticholinergic activity observed. A high antihistaminic activity was also shown in in vivo tests on chemical mediators release by compound 48/80, histamine-induced bronchospasm in anesthetized guinea pigs and histamine-induced cutaneous reaction in beagle dogs. The antiallergic activity was studied in passive cutaneous anaphylaxis test using ovalbumin antibodies. Astemizole and E-4716 had similar activities with ED50 values of 0.8 and 0.5 mg/kg, respectively, whereas terfenadine (ED50 = 4.5) was less active. E-4716 also inhibited the vascular permeability response in histamine-stimulated conjunctivitis model after topical ocular administration (ED50 = 0.002, 0.0002, 0.015 and 1.2% at 30 min and 6, 12 and 24 h, respectively). E-4716 had a high and selective antihistaminic and antiallergic activity by all routes of administration (oral, i.v., i.p., topical ocular and inhalation). These results, combined with its low toxicity and lack of central effects, indicate that E-4716 has excellent potential for therapeutic use.