Trypanosoma cruzi defined antigens in the serological evaluation of an outbreak of acute Chagas disease in Brazil (Catolé do Rocha, Paraíba)

Immunoglobulin G and M humoral response to recombinant protein B13 and glycoconjugate LPPG Trypanosoma cruzi defined antigens was evaluated by ELISA in 18 patients in the acute phase of Chagas disease, who were contaminated on the same occasion. LPPG showed 100% positivity detecting both IgM and IgG antibodies, while positivity of 55-65% was observed for B13. An epimastigote alkaline extract (EPI) also showed high sensitivity for acute IgM (100%) and IgG (90%) antibodies. However LPPG had better discriminatory reactivity since with EPI two patients showed negative IgG and several other sera presented OD values for IgG and IgM antibodies very close to the cutoff. Thus, it is suggested that detection of IgM antibodies by LPPG may be used for diagnosis of the acute phase of Chagas disease. An intense decline of IgG and IgM antibodies to the three antigens was observed in response to anti-T. cruzi chemotherapy in all acute phase patients. After treatment, six (30%) individuals maintained IgG positivity to EPI, LPPG, and B13 with lower reactivity than that measured at the acute phase. For comparison, serology of a group of 22 patients in the chronic phase of Chagas disease and also submitted to chemotherapy was determined. Positive IgM antibodies to EPI, LPPG and B13 were detected in only 5-9% cases. In all chronic-phase patients IgG antibodies highly reactive to the three antigens were present and no significant decrease resulted after benznidazole administration. These observations reinforce previous reports that treatment in the acute phase may reduce or eliminate the parasite.

Vedolizumab as induction and maintenance therapy for Crohn's disease.

BACKGROUND: The efficacy of vedolizumab, an α4β7 integrin antibody, in Crohn's disease is unknown. METHODS: In an integrated study with separate induction and maintenance trials, we assessed intravenous vedolizumab therapy (300 mg) in adults with active Crohn's disease. In the induction trial, 368 patients were randomly assigned to receive vedolizumab or placebo at weeks 0 and 2 (cohort 1), and 747 patients received open-label vedolizumab at weeks 0 and 2 (cohort 2); disease status was assessed at week 6. In the maintenance trial, 461 patients who had had a response to vedolizumab were randomly assigned to receive placebo or vedolizumab every 8 or 4 weeks until week 52. RESULTS: At week 6, a total of 14.5% of the patients in cohort 1 who received vedolizumab and 6.8% who received placebo were in clinical remission (i.e., had a score on the Crohn's Disease Activity Index [CDAI] of ≤150, with scores ranging from 0 to approximately 600 and higher scores indicating greater disease activity) (P=0.02); a total of 31.4% and 25.7% of the patients, respectively, had a CDAI-100 response (≥100-point decrease in the CDAI score) (P=0.23). Among patients in cohorts 1 and 2 who had a response to induction therapy, 39.0% and 36.4% of those assigned to vedolizumab every 8 weeks and every 4 weeks, respectively, were in clinical remission at week 52, as compared with 21.6% assigned to placebo (P<0.001 and P=0.004 for the two vedolizumab groups, respectively, vs. placebo). Antibodies against vedolizumab developed in 4.0% of the patients. Nasopharyngitis occurred more frequently, and headache and abdominal pain less frequently, in patients receiving vedolizumab than in patients receiving placebo. Vedolizumab, as compared with placebo, was associated with a higher rate of serious adverse events (24.4% vs. 15.3%), infections (44.1% vs. 40.2%), and serious infections (5.5% vs. 3.0%). CONCLUSIONS: Vedolizumab-treated patients with active Crohn's disease were more likely than patients receiving placebo to have a remission, but not a CDAI-100 response, at week 6; patients with a response to induction therapy who continued to receive vedolizumab (rather than switching to placebo) were more likely to be in remission at week 52. Adverse events were more common with vedolizumab. (Funded by Millennium Pharmaceuticals; GEMINI 2 ClinicalTrials.gov number, NCT00783692.).

The immunopathology of human schistosomiasis-III: immunoglobulin isotype profiles and response to praziquantel

Immunoglobulin (Ig) isotype (IgG, IgG1, IgG2, IgG3, IgG4, IgM, IgD and IgE) levels were investigated, both pre- and post-treatment with praziquantel (PZQ), in 43 adults and children chronically infected with Schistosoma mansoni , by means of a two-site, isotype-specific immunoenzymometric assay. The patients were classified as responders (R) or non-responders (NR) on the basis of their circumoval precipitin test (COPT) results 12 months after treatment. In comparison with controls, pre-treatment R children showed significantly higher levels of IgG, IgG1, IgG4 (p<0.001) and IgE (p<0.01), and diminished IgG2 (p<0.05), while NR children showed significantly elevated levels only of IgE (p<0.05). Twelve months after therapy, R children maintained significantly lower levels of IgG2, but showed significantly decreased levels of IgG, IgG1, IgG4, and IgE, while the Ig isotype profile of NR children was unaltered. Adult R and NR showed similar isotype profiles before chemotherapy, with the exception of significantly elevated IgM levels in R. Twelve months after therapy, R adults showed significantly decreased levels of IgG, IgG1, and IgG4, while NR adults showed only diminshed IgG4 levels. These results reveal different Ig isotype profiles in untreated adults and children chronically infected with S. mansoni. The results further show that the pre-treatment Ig isotype profile may be significantly modified after an effective R to chemotherapy, accounted for by down regulation of the IgG1 isotype in association with negative seroconversion of the COPT in R patients. The COPT reaction has been associated with the highly specific egg glycoprotein antigen w1, which shows a significant reduction in reactivity six months after treatment. IgG1 may thus play a main role in the response against the w1 antigen.

Voriconazole-Induced Inhibition of the Fungicidal Activity of Amphotericin B in Candida Strains with Reduced Susceptibility to Voriconazole: an Effect Not Predicted by the MIC Value Alone.

An antagonistic effect of voriconazole on the fungicidal activity of sequential doses of amphotericin B has previously been demonstrated in Candida albicans strains susceptible to voriconazole. Because treatment failure and the need to switch to other antifungals are expected to occur more often in infections that are caused by resistant strains, it was of interest to study whether the antagonistic effect was still seen in Candida strains with reduced susceptibility to voriconazole. With the hypothesis that antagonism will not occur in voriconazole-resistant strains, C. albicans strains with characterized mechanisms of resistance against voriconazole, as well as Candida glabrata and Candida krusei strains with differences in their degrees of susceptibility to voriconazole were exposed to voriconazole or amphotericin B alone, to both drugs simultaneously, or to voriconazole followed by amphotericin B in an in vitro kinetic model. Amphotericin B administered alone or simultaneously with voriconazole resulted in fungicidal activity. When amphotericin B was administered after voriconazole, its activity was reduced (median reduction, 61%; range, 9 to 94%). Levels of voriconazole-dependent inhibition of amphotericin B activity differed significantly among the strains but were not correlated with the MIC values (correlation coefficient, -0.19; P = 0.65). Inhibition was found in C. albicans strains with increases in CDR1 and CDR2 expression but not in the strain with an increase in MDR1 expression. In summary, decreased susceptibility to voriconazole does not abolish voriconazole-dependent inhibition of the fungicidal activity of amphotericin B in voriconazole-resistant Candida strains. The degree of interaction could not be predicted by the MIC value alone.

Circulating soluble CR1 (CD35). Serum levels in diseases and evidence for its release by human leukocytes.

C receptor type 1 (CR1, CD35) is present in a soluble form in plasma (sCR1). Soluble CR1 was measured with a specific ELISA assay in normal individuals and in patients with different diseases. The mean serum concentration of sCR1 in 31 normal donors was 31.4 +/- 7.8 ng/ml, and was identical in plasma. An increase in sCR1 was observed in 36 patients with end-stage renal failure on dialysis (54.8 +/- 11.7 ng/ml, p &lt; 0.0001), and in 22 patients with liver cirrhosis (158.3 +/- 49.9 ng/ml, p &lt; 0.0001). The mean sCR1 levels dropped from 181 +/- 62.7 to 52.1 +/- 24.0 ng/ml (p &lt; 0.001) in nine patients who underwent liver transplantation, and was 33.5 +/- 7.3 in 10 patients with functioning renal grafts, indicating that the increase in sCR1 was reversible. Soluble CR1 was elevated in some hematologic malignancies (&gt; 47 ng/ml), which included B cell lymphoma (12/19 patients), Hodgkin's lymphoma (4/4), and chronic myeloproliferative syndromes (4/5). By contrast, no increase was observed in acute myeloid or lymphoblastic leukemia (10) or myeloma (5). In two patients with chronic myeloproliferative syndromes, sCR1 decreased rapidly after chemotherapy. The mean concentration of sCR1 was not significantly modified in 181 HIV-infected patients at various stages of the disease (34.8 +/- 14.4 ng/ml), and in 13 patients with active SLE (38.3 +/- 19.6 ng/ml), although in both groups the number of CR1 was diminished on E. There was a weak but significant correlation between sCR1 and CR1 per E in HIV infection and SLE (r = 0.39, p &lt; 0.0001, and r = 0.60, p &lt; 0.03 respectively). In vitro, monocytes, lymphocytes, and neutrophils were found to release sCR1 into culture supernatants. In vivo, sCR1 was detected in the serum of SCID mice populated with human peripheral blood leukocytes. The sCR1 levels correlated with those of human IgG (r = 0.97, p &lt; 0.0001), suggesting synthesis of sCR1 by the transferred lymphocytes. The mechanisms underlining the increased levels of sCR1 and its biologic consequences remain to be defined.

Phase II study of weekly plitidepsin as second-line therapy for small cell lung cancer.

OBJECTIVE: To evaluate the antitumor activity and safety profile of plitidepsin administered as a 1h weekly intravenous (i.v.) infusion of 3.2mg/m(2) to patients with small cell lung cancer (SCLC) who relapsed or progressed after one line of chemotherapy. PATIENTS AND METHODS: This was a multicenter, open-label, single-arm, exploratory, phase II clinical trial. Treatment lasted until disease progression, unacceptable toxicity, patient refusal or treatment delay for >2 weeks. Objective response rate (primary efficacy endpoint) was evaluated according to response evaluation criteria in solid tumors (RECIST). The rate of stable disease (SD) lasting for at least 6 months and time-to-event variables were secondary endpoints of efficacy. Toxicity was assessed using National Cancer Institute Common Toxicity Criteria (NCI-CTC) version 2.0. RESULTS: Twenty pretreated SCLC patients (median age, 60 years) with extensive (n=13) or limited-stage disease (n=7) received a total of 24 treatment cycles (median, one cycle per patient; range, 1-2). Objective tumor responses were not observed and only one of the 17 evaluable patients had SD. With a median follow-up of 11.8 months, the progression-free survival and the median overall survival were 1.3 months and 4.8 months, respectively. The most troubling or common toxicities were fatigue, muscle weakness, lymphopenia, anemia (no patients showed neutropenia), and asymptomatic, non-cumulative increase of transaminases levels and alkaline phosphatase. CONCLUSION: This clinical trial shows that a cycle of 1h weekly i.v. infusion of plitidepsin (3.2mg/m(2)) was generally well tolerated other than fatigue and muscle weakness in patients with pretreated SCLC. One patient died due to multi-organ failure. The absence of antitumor activity found here precludes further studies of this plitidepsin schedule as second-line single-agent treatment of SCLC.

Sensitivity of Leishmania spp. to Glibenclamide and 4-Aminopiridine: A Tool for the Study of Drug Resistance Development

We have demonstrated that Leishmania spp. grown as promastigotes, are sensitive to the K+ channel inhibitors 4-aminopyridine and glibenclamide. Their host cells, the macrophages, are not affected by similar concentrations of the drugs. We have also initiated the molecular characterization of the mechanisms involved in the development of drug resistance to glibenclamide by the parasite. Therefore, we have selected experimentally and begun to characterize the Venezuelan Leishmania (Leishmania) strain, NR resistant to glibenclamide [NR(Gr)]. The analysis of genomic DNA evidenced the existence of a fragment which apparently is amplified in NR(Gr). The fragment recognized by the pgpA probe, related to the Leishmania P-glycoprotein family and which was originally isolated from L. tarentolae, showed a size polymorfism between the sensitive and the resistant strain. These results suggest that the development of resistance to glibenclamide in the strain NR(Gr) might be associated with the amplification of the ltpgpA or related gene(s)

VeriStrat(®) has a prognostic value for patients with advanced non-small cell lung cancer treated with erlotinib and bevacizumab in the first line: Pooled analysis of SAKK19/05 and NTR528.

BACKGROUND: VeriStrat(®) is a serum proteomic test used to determine whether patients with advanced non-small cell lung cancer (NSCLC) who have already received chemotherapy are likely to have good or poor outcomes from treatment with gefitinib or erlotinib. The main objective of our retrospective study was to evaluate the role of VS as a marker of overall survival (OS) in patients treated with erlotinib and bevacizumab in the first line. PATIENTS AND METHODS: Patients were pooled from two phase II trials (SAKK19/05 and NTR528). For survival analyses, a log-rank test was used to determine if there was a statistically significant difference between groups. The hazard ratio (HR) of any separation was assessed using Cox proportional hazards models. RESULTS: 117 patients were analyzed. VeriStrat classified patients into two groups which had a statistically significant difference in duration of OS (p=0.0027, HR=0.480, 95% confidence interval: 0.294-0.784). CONCLUSION: VeriStrat has a prognostic role in patients with advanced, nonsquamous NSCLC treated with erlotinib and bevacizumab in the first line. Further work is needed to study the predictive role of VeriStrat for erlotinib and bevacizumab in chemotherapy-untreated patients.

Individual versus standard quality of life assessment in a phase II clinical trial in mesothelioma patients: feasibility and responsiveness to clinical changes.

BACKGROUND: In patients with malignant pleural mesothelioma undergoing a multimodality therapy, treatment toxicity may outweigh the benefit of progression-free survival. The subjective experience across different treatment phases is an important clinical outcome. This study compares a standard with an individual quality of life (QoL) measure used in a multi-center phase II trial. PATIENTS AND METHODS: Sixty-one patients with stage I-III technically operable pleural mesothelioma were treated with preoperative chemotherapy, followed by pleuropneumonectomy and subsequent radiotherapy. QoL was assessed at baseline, at day 1 of cycle 3, and 1, 3 and 6 months post-surgery by using the Rotterdam Symptom Checklist (RSCL) and the Schedule for the Evaluation of Quality of Life-Direct Weighting (SEIQoL-DW), a measure that is based on five individually nominated and weighted QoL-domains. RESULTS: Completion rates were 98% (RSCL) and 92% (SEIQoL) at baseline and 98%/89% at cycle 3, respectively. Of the operated patients (N=45) RSCL and SEIQoL were available from 86%/72%, 93%/74%, and 94%/76% at months 1, 3, and 6 post-surgery. Average assessment time for the SEIQoL was 24min compared to 8min needed for the RSCL. Median changes from baseline indicate that both RSCL QoL overall score and SEIQoL index remained stable during chemotherapy with a clinically significant deterioration (change>or=8 points) 1 month after surgery (median change of -66 and -14 for RSCL and SEIQoL, respectively). RSCL QoL overall scores improved thereafter, but remained beneath baseline level until 6 months after surgery. SEIQoL scores improved to baseline-level at month 3 after surgery, but worsened again at month 6. RSCL QoL overall score and SEIQoL index were moderately correlated at baseline (r=.30; p<or=.05) and at 6-month follow-up (r=.42; p<or=.05) but not at the other time points. CONCLUSION: The SEIQoL assessment seems to be feasible within a phase II clinical trial, but may require more effort from staff. More distinctive QoL changes in accordance with clinical changes were measured with the RSCL. Our findings suggest that the two measures are not interchangeable: the RSCL is to favor when mainly information related to the course of disease- and treatment is of interest.

A single mutation in enzyme I of the sugar phosphotransferase system confers penicillin tolerance to Streptococcus gordonii.

Tolerance is a poorly understood phenomenon that allows bacteria exposed to a bactericidal antibiotic to stop their growth and withstand drug-induced killing. This survival ability has been implicated in antibiotic treatment failures. Here, we describe a single nucleotide mutation (tol1) in a tolerant Streptococcus gordonii strain (Tol1) that is sufficient to provide tolerance in vitro and in vivo. It induces a proline-to-arginine substitution (P483R) in the homodimerization interface of enzyme I of the sugar phosphotransferase system, resulting in diminished sugar uptake. In vitro, the susceptible wild-type (WT) and Tol1 cultures lost 4.5 and 0.6 log(10) CFU/ml, respectively, after 24 h of penicillin exposure. The introduction of tol1 into the WT (WT P483R) conferred tolerance (a loss of 0.7 log(10) CFU/ml/24 h), whereas restitution of the parent sequence in Tol1 (Tol1 R483P) restored antibiotic susceptibility. Moreover, penicillin treatment of rats in an experimental model of endocarditis showed a complete inversion in the outcome, with a failure of therapy in rats infected with WT P483R and the complete disappearance of bacteria in animals infected with Tol1 R483P.

Late biliary complications in human alveolar echinococcosis are associated with high mortality.

AIM: To evaluate the incidence of late biliary complications in non-resectable alveolar echinococcosis (AE) under long-term chemotherapy with benzimidazoles. METHODS: Retrospective analysis of AE patients with biliary complications occurring more than three years after the diagnosis of AE. We compared characteristics of patients with and without biliary complications, analyzed potential risk factor for biliary complications and performed survival analyses. RESULTS: Ninety four of 148 patients with AE in Zurich had non-resectable AE requiring long-term benzimidazole chemotherapy, of which 26 (28%) patients developed late biliary complications. These patients had a median age of 55.5 (35.5-65) years at diagnosis of AE and developed biliary complications after 15 (8.25-19) years of chemotherapy. The most common biliary complications during long-term chemotherapy were late-onset cholangitis (n = 14), sclerosing cholangitis-like lesions (n = 8), hepatolithiasis (n = 5), affection of the common bile duct (n = 7) and secondary biliary cirrhosis (n = 7). Thirteen of the 26 patients had undergone surgery (including 12 resections) before chemotherapy. Previous surgery was a risk factor for late biliary complications in linear regression analysis (P = 0.012). CONCLUSION: Late biliary complications can be observed in nearly one third of patients with non-resectable AE, with previous surgery being a potential risk factor. After the occurrence of late biliary complications, the median survival is only 3 years, suggesting that late biliary complications indicate a poor prognostic outcome.

Mitotic figure counts are significantly overestimated in resection specimens of invasive breast carcinomas.

Several authors have demonstrated an increased number of mitotic figures in breast cancer resection specimen when compared with biopsy material. This has been ascribed to a sampling artifact where biopsies are (i) either too small to allow formal mitotic figure counting or (ii) not necessarily taken form the proliferating tumor periphery. Herein, we propose a different explanation for this phenomenon. Biopsy and resection material of 52 invasive ductal carcinomas was studied. We counted mitotic figures in 10 representative high power fields and quantified MIB-1 immunohistochemistry by visual estimation, counting and image analysis. We found that mitotic figures were elevated by more than three-fold on average in resection specimen over biopsy material from the same tumors (20±6 vs 6±2 mitoses per 10 high power fields, P=0.008), and that this resulted in a relative diminution of post-metaphase figures (anaphase/telophase), which made up 7% of all mitotic figures in biopsies but only 3% in resection specimen (P<0.005). At the same time, the percentages of MIB-1 immunostained tumor cells among total tumor cells were comparable in biopsy and resection material, irrespective of the mode of MIB-1 quantification. Finally, we found no association between the size of the biopsy material and the relative increase of mitotic figures in resection specimen. We propose that the increase in mitotic figures in resection specimen and the significant shift towards metaphase figures is not due to a sampling artifact, but reflects ongoing cell cycle activity in the resected tumor tissue due to fixation delay. The dwindling energy supply will eventually arrest tumor cells in metaphase, where they are readily identified by the diagnostic pathologist. Taken together, we suggest that the rapidly fixed biopsy material better represents true tumor biology and should be privileged as predictive marker of putative response to cytotoxic chemotherapy.

Schistosomiasis control in Brazil

In 1975 the Special Programme for Schistosomiasis Control was introduced in Brazil with the objective of controlling this parasitic disease in six northeastern states. The methodology applied varied largely from state to state, but was based mainly on chemotherapy, This Programme was modified about ten years after it beginning with the main goals including control of morbidity and the blockage of establishment of new foci in non-endemic areas. In two states, Bahia and Minas Gerais, the schistosomiasis control programme started in 1979 and 1983, respectively. The recently made evaluation of those two programmes is the main focus of this paper. It must also be pointed out, that the great majority of the studies performed by different researchers in Brazil, at different endemic areas, consistently found significant decrease on prevalence and incidence, when control measures are repeatedly used for several years. Significant decrease of hepatosplenic forms in the studied areas is well documented in Brazil. After more than 20 years of schistosomiasis control programmes in our country, chemotherapy has shown to be a very important tool for the control of morbidity and to decrease prevalence and incidence in endemic areas. Nevertheless, in medium and long terms, sanitation, water supply, sewage draining and health education seem to be the real tools when the aim is persistent and definitive schistosomiasis control.

Combination of transient lymphodepletion with busulfan and fludarabine and peptide vaccination in a phase I clinical trial for patients with advanced melanoma.

Taking advantage of homeostatic mechanisms to boost tumor-specific cellular immunity is raising increasing interest in the development of therapeutic strategies in the treatment of melanoma. Here, we have explored the potential of combining homeostatic proliferation, after transient immunosuppression, and antigenic stimulation of Melan-A/Mart-1 specific CD8 T-cells. In an effort to develop protocols that could be readily applicable to the clinic, we have designed a phase I clinical trial, involving lymphodepleting chemotherapy with Busulfan and Fludarabine, reinfusion of Melan-A specific CD8 T-cell containing peripheral blood mononuclear cells (exempt of growth factors), and Melan-A peptide vaccination. Six patients with advanced melanoma were enrolled in this outpatient regimen that demonstrated good feasibility combined with low toxicity. Consistent depletion of lymphocytes with persistent increased CD4/CD8 ratios was induced, although the proportion of circulating CD4 regulatory T-cells remained mostly unchanged. The study of the immune reconstitution period showed a steady recovery of whole T-cell numbers overtime. However, expansion of Melan-A specific CD8 T-cells, as measured in peripheral blood, was mostly inconsistent, accompanied with marginal phenotypic changes, despite vaccination with Melan-A/Mart-1 peptide. On the clinical level, 1 patient presented a partial but objective antitumor response following the beginning of the protocol, even though a direct effect of Busulfan/Fludarabine cannot be completely ruled out. Overall, these data provide further ground for the development of immunotherapeutic approaches to be both effective against melanoma and applicable in clinic.

Different approaches to modelling the cost-effectiveness of schistosomiasis control

This paper reviews three different approaches to modelling the cost-effectiveness of schistosomiasis control. Although these approaches vary in their assessment of costs, the major focus of the paper is on the evaluation of effectiveness. The first model presented is a static economic model which assesses effectiveness in terms of the proportion of cases cured. This model is important in highlighting that the optimal choice of chemotherapy regime depends critically on the level of budget constraint, the unit costs of screening and treatment, the rates of compliance with screening and chemotherapy and the prevalence of infection. The limitations of this approach is that it models the cost-effectiveness of only one cycle of treatment, and effectiveness reflects only the immediate impact of treatment. The second model presented is a prevalence-based dynamic model which links prevalence rates from one year to the next, and assesses effectiveness as the proportion of cases prevented. This model was important as it introduced the concept of measuring the long-term impact of control by using a transmission model which can assess reduction in infection through time, but is limited to assessing the impact only on the prevalence of infection. The third approach presented is a theoretical framework which describes the dynamic relationships between infection and morbidity, and which assesses effectiveness in terms of case-years prevented of infection and morbidity. The use of this model in assessing the cost-effectiveness of age-targeted treatment in controlling Schistosoma mansoni is explored in detail, with respect to varying frequencies of treatment and the interaction between drug price and drug efficacy.