Parkin Deficiency Suppresses Antigen Presentation to Promote Tumor Immune Evasion and Immunotherapy Resistance

Parkin is an E3 ubiquitin ligase, which plays a key role in the development of Parkinson disease. Parkin defects also occur in numerous cancers, and a growing body of evidence indicates that Parkin functions as a tumor suppressor that impedes a number of cellular processes involved in tumorigenesis. Here, we generated murine and human models that closely mimic the advanced-stage tumors where Parkin deficiencies are found to provide deeper insights into the tumor suppressive functions of Parkin. Loss of Parkin expression led to aggressive tumor growth, which was associated with poor tumor antigen presentation and limited antitumor CD8+ T-cell infiltration and activation. The effect of Parkin deficiency on tumor growth was lost following depletion of CD8+ T cells. In line with previous findings, Parkin deficiency was linked with mitochondria-associated metabolic stress, PTEN degradation, and enhanced Akt activation. Increased Akt signaling led to dysregulation of antigen presentation, and treatment with the Akt inhibitor MK2206-2HCl restored antigen presentation in Parkin-deficient tumors. Analysis of data from patients with clear cell renal cell carcinoma indicated that Parkin expression was downregulated in tumors and that low expression correlated with reduced overall survival. Furthermore, low Parkin expression correlated with reduced patient response to immunotherapy. Overall, these results identify a role for Parkin deficiency in promoting tumor immune evasion that may explain the poor prognosis associated with loss of Parkin across multiple types of cancer.

SIGNIFICANCE

Parkin prevents immune evasion by regulating tumor antigen processing and presentation through the PTEN/Akt network, which has important implications for immunotherapy treatments in patients with Parkin-deficient tumors.

Hybrid Polyelectrolyte Nanocomplexes for Non-Viral Gene Delivery with Favorable Efficacy and Safety Profile

The development of nanovectors for precise gene therapy is increasingly focusing on avoiding uncontrolled inflammation while still being able to effectively act on the target sites. Herein, we explore the use of non-viral hybrid polyelectrolyte nanocomplexes (hPECs) for gene delivery, which display good transfection efficacy coupled with non-inflammatory properties. Monodisperse hPECs were produced through a layer-by-layer self-assembling of biocompatible and biodegradable polymers. The resulting nanocomplexes had an inner core characterized by an EGFP-encoding plasmid DNA (pDNA) complexed with linear polyethyleneimine or protamine (PEI or PRM) stabilized with lecithin and poly(vinyl alcohol) (PVA) and an outer layer consisting of medium-molecular-weight chitosan (CH) combined with tripolyphosphate (TPP). PEI- and PRM-hPECs were able to efficiently protect the genetic cargo from nucleases and to perform a stimuli-responsive release of pDNA overtime, thus guaranteeing optimal transfection efficiency. Importantly, hPECs revealed a highly cytocompatible and a non-inflammatory profile in vitro. These results were further supported by evidence of the weak and unspecific interactions of serum proteins with both hPECs, thus confirming the antifouling properties of their outer shell. Therefore, these hPECs represent promising candidates for the development of effective, safe nanotools for gene delivery.

Combination of vasculature targeting, hypofractionated radiotherapy, and immune checkpoint inhibitor elicits potent antitumor immune response and blocks tumor progression

Background

Tumor endothelial marker 1 (TEM1) is a protein expressed in the tumor-associated endothelium and/or stroma of various types of cancer. We previously demonstrated that immunization with a plasmid-DNA vaccine targeting TEM1 reduced tumor progression in three murine cancer models. Radiation therapy (RT) is an established cancer modality used in more than 50% of patients with solid tumors. RT can induce tumor-associated vasculature injury, triggering immunogenic cell death and inhibition of the irradiated tumor and distant non-irradiated tumor growth (abscopal effect). Combination treatment of RT with TEM1 immunotherapy may complement and augment established immune checkpoint blockade.

Methods

Mice bearing bilateral subcutaneous CT26 colorectal or TC1 lung tumors were treated with a novel heterologous TEM1-based vaccine, in combination with RT, and anti-programmed death-ligand 1 (PD-L1) antibody or combinations of these therapies, tumor growth of irradiated and abscopal tumors was subsequently assessed. Analysis of tumor blood perfusion was evaluated by CD31 staining and Doppler ultrasound imaging. Immunophenotyping of peripheral and tumor-infiltrating immune cells as well as functional analysis was analyzed by flow cytometry, ELISpot assay and adoptive cell transfer (ACT) experiments.

Results

We demonstrate that addition of RT to heterologous TEM1 vaccination reduces progression of CT26 and TC1 irradiated and abscopal distant tumors as compared with either single treatment. Mechanistically, RT increased major histocompatibility complex class I molecule (MHCI) expression on endothelial cells and improved immune recognition of the endothelium by anti-TEM1 T cells with subsequent severe vascular damage as measured by reduced microvascular density and tumor blood perfusion. Heterologous TEM1 vaccine and RT combination therapy boosted tumor-associated antigen (TAA) cross-priming (ie, anti-gp70) and augmented programmed cell death protein 1 (PD-1)/PD-L1 signaling within CT26 tumor. Blocking the PD-1/PD-L1 axis in combination with dual therapy further increased the antitumor effect and gp70-specific immune responses. ACT experiments show that anti-gp70 T cells are required for the antitumor effects of the combination therapy.

Conclusion

Our findings describe novel cooperative mechanisms between heterologous TEM1 vaccination and RT, highlighting the pivotal role that TAA cross-priming plays for an effective antitumor strategy. Furthermore, we provide rationale for using heterologous TEM1 vaccination and RT as an add-on to immune checkpoint blockade as triple combination therapy into early-phase clinical trials.

Economic evaluation of sunitinib versus pazopanib and best supportive care for the treatment of metastatic renal cell carcinoma in Chile: cost-effectiveness analysis and a mixed treatment comparison

Background: Sunitinib and Pazopanib are two metastatic renal cell carcinoma (MRCC) treatment alternatives, however the health system in Chile does not consider coverage for any. The cost-effectiveness versus relevant comparator was assessed to support evidence-based decision making. Methods: A four health states Markov model was built: first, second line treatments, BSC and death. Benefits were measured in QALYs, and efficacy estimates were obtained from an indirect treatment comparison. A 10-year time horizon and a 3% undifferentiated discount rate were considered. Deterministic and probabilistic sensitivity analyses were performed. Results: The costs of treating MRCC with Sunitinib were higher than Pazopanib and BSC. When comparing Sunitinib versus Pazopanib, the incremental benefit is small favoring Sunitinib (0.03 QALYs). The base case scenario shows an average ICER of PA versus BSC of US$62,327.11/QALY and of US$85,885/QALY for Sunitinib versus Pazopanib. The ICER was most sensitive to the OS relative to BSC, where evidence was associated to important bias. Conclusions: Sunitinib or Pazopanib can be considered cost-effective if a 3 GDP per-capita threshold is assumed. The decision between SU or PA is highly sensitive to the price of the drugs, rather than the outcomes. Therefore, the decision might be made based on cost-minimization exercise.

Estudio de impacto presupuestal de Daclatasvir asociado a Asunaprevir desde la perspectiva del sistema de salud público chileno

OBJECTIVES

To assess the impact on the 2015 national health budget of incorporating Daclatasvir/Asunaprevir (DCV / ASV) for the treatment of Hepatitis C genotype 1b (HC1b) in Chile.

METHODS

A Chilean HC1b patients cohort was modelled using local prevalence and incidence data. Two scenarios were built and compared, one were all patients receive Peginterferon/Ribavirin (PR) and another were all patients are treated with DCV/ASV. The analysis was conducted from the perspective of public health system of Chile assuming 100% reimbursement and a time horizon of 5 years. Costs associated with drug treatment, adverse events, other relevant resources and costs associated with disease complications were used.

RESULTS

At a total DCV/ASV treatment price of USD $55,039, an additional of USD $65,6MM are required during the first year (prevalent cases) equivalent to 0.71% of the 2015 national health budget. From year 2 (incident cases), an additional of USD $12,3MM are needed (0.13% of the 2015 health budget). A price reduction of 33% (USD $36,693), requires an additional of USD $38,2MM the first year and USD $7,16MM from the second year (0.11% and 0.6% of the health budget). If the treatment price is reduced further (USD $18,347), an additional USD $10,9MM are required for the first year and USD $2,03MM from the second year (0.3% and 0.057% of the 2015 heath budget).

CONCLUSION

The impact on the health budget ranges between 0.3% and 0.71% the first year and decreases to less than 0.15% from the second year considering the price assessed price range.

Activation of the kynurenine pathway predicts poor outcome in patients with clear cell renal cell carcinoma

OBJECTIVE

To investigate the expression of the kynurenine (KYN) pathway components and the prognostic role of the KYN-to-tryptophan ratio (KTR) in a cohort of patients with clear cell renal cell carcinoma (ccRCC).

MATERIALS AND METHODS

The expression of KYN pathway components was investigated by tissue microarray-based immunohistochemistry, indirect immunofluorescence, and confocal microscopy analysis in 100 ccRCC cases and 30 normal renal samples. The role of this pathway in sustaining cancer cell proliferation, migration, and chemoresistance was evaluated. In addition, tryptophan and KYN concentrations and their ratio were measured in serum of 195 patients with ccRCC using a sandwich enzyme-linked immunosorbent assay. The role of KTR as a prognostic factor for ccRCC cancer-specific survival (CSS) and progression-free survival (PFS) was assessed.

RESULTS

Tissue microarray-based immunohistochemistry and indirect immunofluorescence staining showed an increased signal for KYN pathway components in ccRCC. Kaplan-Meier curves showed significant differences in CSS and PFS among groups of patients with high vs. low KTR. In particular, patients with high KTR values had a 5-year survival rate of 76.9% as compared with 92.3% for subjects with low levels (P  < 0.0001). Similar findings were observed for PFS (72.8% vs. 96.8% at 5y). At multivariate analysis, KTR was an independent adverse prognostic factor for CSS (hazard ratio  = 1.24, P  =  0.001), and PFS (hazard ratio  =  1.14, P  =  0.001).

CONCLUSIONS

The involvement of the KYN pathway enzymes and catabolites in ccRCC occurs via both immune and nonimmune mechanisms. Our data suggest that KTR could serve as a marker of ccRCC aggressiveness and as a prognostic factor for CSS and PFS.

Metabolomic profile of glycolysis and the pentose phosphate pathway identifies the central role of glucose-6-phosphate dehydrogenase in clear cell-renal cell carcinoma

The analysis of cancer metabolome has shown that proliferating tumor cells require a large quantities of different nutrients in order to support their high rate of proliferation. In this study we analyzed the metabolic profile of glycolysis and the pentose phosphate pathway (PPP) in human clear cell-renal cell carcinoma (ccRCC) and evaluate the role of these pathways in sustaining cell proliferation, maintenance of NADPH levels, and production of reactive oxygen species (ROS). Metabolomic analysis showed a clear signature of increased glucose uptake and utilization in ccRCC tumor samples. Elevated levels of glucose-6-phosphate dehydrogenase (G6PDH) in association with higher levels of PPP-derived metabolites, suggested a prominent role of this pathway in RCC-associated metabolic alterations. G6PDH inhibition, caused a significant decrease in cancer cell survival, a decrease in NADPH levels, and an increased production of ROS, suggesting that the PPP plays an important role in the regulation of ccRCC redox homeostasis. Patients with high levels of glycolytic enzymes had reduced progression-free and cancer-specific survivals as compared to subjects with low levels. Our data suggest that oncogenic signaling pathways may promote ccRCC through rerouting the sugar metabolism. Blocking the flux through this pathway may serve as a novel therapeutic target.

Increased Expression of the Autocrine Motility Factor is Associated With Poor Prognosis in Patients With Clear Cell-Renal Cell Carcinoma

Glucose-6-phosphate isomerase (GPI), also known as phosphoglucose isomerase, was initially identified as the second glycolytic enzyme that catalyzes the interconversion of glucose-6-phosphate to fructose-6-phosphate. Later studies demonstrated that GPI was the same as the autocrine motility factor (AMF), and that it mediates its biological effects through the interaction with its surface receptor (AMFR/gp78). In this study, we assessed the role of GPI/AMF as a prognostic factor for clear cell renal cell carcinoma (ccRCC) cancer-specific (CSS) and progression-free survival (PFS). In addition, we evaluated the expression and localization of GPI/AMF and AMFR, using tissue microarray-based immunohistochemistry (TMA-IHC), indirect immunofluorescence (IF), and confocal microscopy analysis.Primary renal tumor and nonneoplastic tissues were collected from 180 patients who underwent nephrectomy for ccRCC. TMA-IHC and IF staining showed an increased signal for both GPI and AMFR in cancer cells, and their colocalization on plasma membrane. Kaplan-Meier curves showed significant differences in CSS and PFS among groups of patients with high versus low GPI expression. In particular, patients with high tissue levels of GPI had a 5-year survival rate of 58.8%, as compared to 92.1% for subjects with low levels (P < 0.0001). Similar findings were observed for PFS (56.8% vs 93.3% at 5 years). At multivariate analysis, GPI was an independent adverse prognostic factor for CSS (HR = 1.26; P = 0.001), and PFS (HR = 1.16; P = 0.01).In conclusion, our data suggest that GPI could serve as a marker of ccRCC aggressiveness and a prognostic factor for CSS and PFS.

Metabolomic profiling for the identification of novel diagnostic markers in prostate cancer

Metabolomic profiling offers a powerful methodology for understanding the perturbations of biochemical systems occurring during a disease process. During neoplastic transformation, prostate cells undergo metabolic reprogramming to satisfy the demands of growth and proliferation. An early event in prostate cell transformation is the loss of capacity to accumulate zinc. This change is associated with a higher energy efficiency and increased lipid biosynthesis for cellular proliferation, membrane formation and cell signaling. Moreover, recent studies have shown that sarcosine, an N-methyl derivative of glycine, was significantly increased during disease progression from normal to localized to metastatic prostate cancer. Mapping the metabolomic profiles to their respective biochemical pathways showed an upregulation of androgen-induced protein synthesis, an increased amino acid metabolism and a perturbation of nitrogen breakdown pathways, along with high total choline-containing compounds and phosphocholine levels. In this review, the role of emerging biomarkers is summarized, based on the current understanding of the prostate cancer metabolome.

Treatment of relapsing mild-to-moderate ulcerative colitis with the probiotic VSL#3 as adjunctive to a standard pharmaceutical treatment: a double-blind, randomized, placebo-controlled study

OBJECTIVES

VSL#3 is a high-potency probiotic mixture that has been used successfully in the treatment of pouchitis. The primary end point of the study was to assess the effects of supplementation with VSL#3 in patients affected by relapsing ulcerative colitis (UC) who are already under treatment with 5-aminosalicylic acid (ASA) and/or immunosuppressants at stable doses.

METHODS

A total of 144 consecutive patients were randomly treated for 8 weeks with VSL#3 at a dose of 3,600 billion CFU/day (71 patients) or with placebo (73 patients).

RESULTS

In all, 65 patients in the VSL#3 group and 66 patients in the placebo group completed the study. The decrease in ulcerative colitis disease activity index (UCDAI) scores of 50% or more was higher in the VSL#3 group than in the placebo group (63.1 vs. 40.8; per protocol (PP) P=0.010, confidence interval (CI)₉₅(%) 0.51-0.74; intention to treat (ITT) P=0.031, CI₉₅(%) 0.47-0.69). Significant results with VSL#3 were recorded in an improvement of three points or more in the UCDAI score (60.5% vs. 41.4%; PP P=0.017, CI₉₅(%) 0.51-0.74; ITT P=0.046, CI₉₅(%) 0.47-0.69) and in rectal bleeding (PP P=0.014, CI₉₅(%) 0.46-0.70; ITT P=0.036, CI₉₅(%) 0.41-0.65), whereas stool frequency (PP P=0.202, CI₉₅(%) 0.39-0.63; ITT P=0.229, CI₉₅(%) 0.35-0.57), physician's rate of disease activity (PP P=0.088, CI₉₅(%) 0.34-0.58; ITT P=0.168, CI₉₅(%) 0.31-0.53), and endoscopic scores (PP P=0.086, CI₉₅(%) 0.74-0.92; ITT P=0.366, CI₉₅(%) 0.66-0.86) did not show statistical differences. Remission was higher in the VSL#3 group than in the placebo group (47.7% vs. 32.4%; PP P=0.069, CI₉₅(%) 0.36-0.60; ITT P=0.132, CI₉₅(%) 0.33-0.56). Eight patients on VSL#3 (11.2%) and nine patients on placebo (12.3%) reported mild side effects.

CONCLUSIONS

VSL#3 supplementation is safe and able to reduce UCDAI scores in patients affected by relapsing mild-to-moderate UC who are under treatment with 5-ASA and/or immunosuppressants. Moreover, VSL#3 improves rectal bleeding and seems to reinduce remission in relapsing UC patients after 8 weeks of treatment, although these parameters do not reach statistical significance.

Randomized phase II study of cisplatin plus gemcitabine administered either as short infusion or at a fixed dose rate in non-small cell lung cancer (NSCLC)

17037

Background: Previous studies have indicated that, in combination with cisplatin (cis), fixed dose rate gemcitabine (gem) may be more efficacious than standard infusion gem. This open-label, randomized, multicenter Phase II study (B9E-LA-S350) was aimed to compare the efficacy and safety of these regimens as treatment for advanced NSCLC in Latin American patients (pts). Methods: Major eligibility criteria included histologic/cytologic diagnosis of stage IIIB/IV NSCLC not amenable to curative surgery; and at least one measurable lesion. Pts were randomized to receive up to 6 cycles of treatment with cis 75 mg/m2 on Day 1 plus either gem 1000 mg/m2 over 30 min on Days 1 and 8 of a 21-day cycle (standard arm) or gem 1000 mg/m2 at a fixed dose rate of 10 mg/ m2/min on Days 1 and 8 of a 21-day cycle (FDR arm). The primary endpoint was the objective response rate (ORR; assessed by RECIST criteria) and secondary endpoints included overall survival (OS), progression-free survival (PFS), duration of tumor response (TR), and toxicity. Results: The results from this interim analysis assessed all objectives. Sixty-four pts were randomized to treatment (N = 33 standard arm; N = 31 FDR arm): 22 females; mean age 60 ± 9 yrs; 20% stage IIIB, 80% stage IV. In the standard arm, 9 (27%) pts responded (CR or PR) compared to 6 (20%) pts in the FDR arm (Odds ratio: 0.67, 95% CI 0.21–2.2, p = .56). As shown in the table below, there were no statistically significant differences in median ORR, OS, PFS, TR times, and Grade (G) 3/4 toxicities. Conclusions: The standard and FDR gem and cis treatment regimens produced similar results for both efficacy and toxicity in this patient population. This trial does not support the use of a FDR administration of gem in Latin American pts with NSCLC.

[Table: see text]

[Table: see text]

Apert syndrome: analysis of associated brain malformations and conformational changes determined by surgical treatment

Apert Syndrome, also called acrocephalosyndactylia type 1, is characterized by craniostenosis with early fusion of sutures of the vault and/or cranial base, associated to mid-face hypoplasia, symmetric syndactylia of the hands and feet and other systemic malformations. CNS malformations and intracranial hypertension are frequently observed in these patients. Early surgical treatment aims to minimize the deleterious effects of intracranial hypertension. Fronto-orbital advancement, the usual surgical technique, increases the intracranial Volume and improves the disposition of encephalic structures previously deformed by a short skull. This study analyzes CNS alterations revealed by magnetic resonance in 18 patients presenting Apert Syndrome, and the conformational alterations in the encephalic structures after surgical treatment. The patients' age in February 2001 ranged from 14 to 322 Months (m=107). Image study included brain magnetic resonance showing ventricular enlargement in five cases (27.8%), corpus callosum hypoplasia in five cases (27.8%), septum pellucidum hypoplasia in five cases (27.8%), cavum vergae in two cases (11.1%) and, arachnoid cyst in the posterior fossa in two cases (11.1%). Absence of CNS alterations was noted in 44.4% of cases. A corpus callosum morphologic index was established by dividing its height by its length, which revealed values that ranged from 0.4409 to 1.0237. The values of this index were correlated to the occurrence or absence of surgical treatment (p=0.012; t=2.83). Data analysis allowed the conclusion that the corpus callosum morphologic measure quantified the conformational alterations of the cerebral structures determined by the surgical treatment.

Lansoprazole-based triple therapy versus ranitidine bismuth citrate-based dual therapy in the eradication of Helicobacter pylori in patients with duodenal ulcer: a multicenter, randomized, double-dummy study

BACKGROUND

The optimal treatment regimen for eradication of Helicobacter pylori in patients with duodenal ulcer has yet to be determined. Based on a search of MEDLINE, no studies have been performed comparing a proton pump inhibitor-based triple therapy regimen with a ranitidine bismuth citrate (RBC)-based dual therapy regimen, both containing clarithromycin.

OBJECTIVE

This study was undertaken to compare the efficacy of lansoprazole (LAN)-based triple therapy with that of RBC-based dual therapy in H pylori-infected patients with duodenal ulcer.

METHODS

Patients were randomized to receive either 1 week of triple therapy with LAN 30 mg BID, clarithromycin 500 mg BID, and tinidazole 500 mg BID, followed by 3 weeks of LAN 30 mg BID, or 2 weeks of dual therapy with RBC 400 mg BID plus clarithromycin 500 mg BID, followed by 2 weeks of RBC 400 mg BID. Eradication of H pylori was defined as negative results on both the urease quick test and histologic examination > or =4 weeks after the end of treatment. Duodenal healing and recurrence rates were assessed endoscopically at 8 weeks and 6 months. A per-protocol (PP) analysis was conducted for each efficacy end point. Also conducted were an intent-to-treat (ITT) analysis in which patients with missing data were considered failures, and an observed analysis (OBS), which included patients with an evaluable result after treatment, regardless of compliance.

RESULTS

One hundred eighty-five patients (126 men, 59 women; age range, 18-76 years; mean age, 43 years) were enrolled and randomized to treatment. In the LAN and RBC groups, respectively, H. pylori eradication rates were 92.6%, 93.1%, and 72.8% versus 78.6%, 77.9%, and 64.5% in the PP (P = 0.02), OBS (P = 0.01), and ITT analyses. The corresponding duodenal ulcer healing rates were 98.6%, 98.7%, and 83.7% versus 90.8%, 91.5%, and 81.7%; these differences were not statistically significant. Side effects were mild, occurring in 20.7% of LAN patients and 17.2% of RBC patients. Ulcer recurred in 2 RBC patients. No difference was observed between treatments in terms of the occurrence of gastritis or improvement of symptoms.

CONCLUSION

Based on the results of the PP and OBS analyses, LAN-based triple therapy was superior to RBC-based dual therapy for the eradication of H. pylori in patients with duodenal ulcer.

Heterogeneity of oral isolates of Candida albicans in HIV-positive patients: correlation between candidal carriage, karyotype and disease stage

Opportunist infections involving Candida albicans often develop in HIV-positive patients and oral lesions tend to become more frequent as the disease progresses. Previous studies have shown contrasting results concerning the variability of the pulsed-field gel electrophoresis (PFGE) subtypes of C. albicans observed in HIV-positive patients. Carriage of C. albicans was determined by an oral rinse technique; 41 strains of C. albicans (78% serotype A and 22% serotype B) were isolated. There was a direct correlation between candidal load (cfu/ml) and the blood HIV load, whereas there was an inverse correlation with the stage of disease and the CD4 cell counts. The PFGE patterns of isolates were variable with regard to the number and positions of bands. The variability of the band sizes in some run positions showed a Gaussian distribution. Generally, the most frequent size variants were associated with the strains with the highest cfu/ml and lowest CD4 counts (< or =200 cells/microl). These findings suggest a possible strain selection over time during disease progression, especially in HIV-positive subjects with low CD4 counts.

DNA heterogeneity of Staphylococcus aureus strains evaluated by SmaI and SgrAI pulsed-field gel electrophoresis in patients with impetigo

To our knowledge, no studies have previously been carried out on the heterogeneity and intrafamily colonization of impetigo Staphylococcus aureus strains obtained by powerful discriminating methods such as pulsed-field gel electrophoresis (PFGE). To explore this topic, macrorestriction patterns of S. aureus strains were analyzed after SmaI and SgrAI digestion. The two enzymes provided superimposable results. A total of ninety-seven S. aureus strains was found in the 26 families whose lesions and nasal and pharyngeal samples were examined. There were 39 strains which were different by PFGE, and of these, 24 were found in the lesions. Although 85% of impetigo patients showed nasal colonization and 58% showed pharyngeal colonization, only 54% of the patients had the same PFGE strain in the lesion and in the nose, and 35% in the lesion and the pharynx. In half of the 26 families, at least one member (mother, father, or relative) presented a S. aureus strain identical, by PFGE, to strains isolated in patients' lesions. Nineteen percent of mothers, 15% of fathers, and 19% of the other relatives presented nasal colonization with strains identical to those isolated in the children's lesions. Lesional strains showed higher antimicrobial resistance than nonlesional isolates.

S. aureus PFGE patterns of lesional or non lesional strains from patients with impetigo: association of individual bands with lesional or non lesional areas

PFGE has been extensively used to obtain a reliable intra-species differentiation, although this technique has not been completely standardized. In this study, PFGE was applied to analyze in detail the patterns of 19 lesional S. aureus strains isolated from patients with impetigo, compared with 15 non-lesional strains isolated from nasal or pharyngeal swabs of the same patients. The strain DNA was extracted and processed as previously reported, using the strictest protocol to limit the variations between different analytical sets. To obtain maximum sensitivity and comparability, the electrophoresis patterns were analyzed by an automated and computerized reader (GelDoc1000). The DNA fragments (range 12-15 bands) obtained for each individual strain were then divided into 39 zones including from 1 to 4 bands for a total of at least 91 possible different gel positions. The positivity for each zone (and/or the positivity for the individual bands contained) was associated with the lesional/non-lesional origin and with the face localization of the strains.

Association between lesional or non lesional S. aureus strains from patients with impetigo and exfoliative toxin production. No association with SmaI PFGE patterns

Contrasting data are reported in the literature on the percent positivity rates (13.5%-100%) of exfoliative toxin (ET) production by S. aureus strains isolated from impetigo patients in Japan and in France. In the present study, by means of a recently available latex-test, toxin-A (ETA) or toxin-B (ETB) production was found in 67.6% of the 34 S. aureus strains isolated from 19 lesional (63.2%) and 15 non-lesional (nose or pharynx, 73.3%) areas of patients with impetigo (with no significant difference between the lesional and non-lesional isolates). ETA + ETB were produced by 44.1% of the strains, while 32.4% were non-producers. In contrast, the percent positivity rate observed in 40 [20 lesional and 20 non-lesional (nose or pharynx)] strains isolated in patients with atopic dermatitis was 15.0% (p < 0.001 both for the lesional and non-lesional strains versus impetigo, with no significant difference between lesional and non lesional strains). Finally, 26 strains from other types of specimens (abscesses, hemocultures, urine, central venous catheters, bronchoalveolar lavages) showed an 11.5% production rate of ETA or ETB (p < 0.001 versus impetigo strains, no significance versus atopic dermatitis). These data point to a significant association between exfoliative toxin production and S. aureus strains isolated in impetigo, both in lesional areas and in nasal/pharyngeal reservoirs. An attempt to correlate SmaI pulsed-field gel electrophoresis (PFGE) restriction patterns and exfoliative toxin production showed no significant association in either group.

Lack of evidence for increased risk of hepatitis A infection in homosexual men

In 1997, prevalence of and risk factors for hepatitis A virus (HAV) infection were evaluated in 146 homosexual and 286 heterosexual men attending a Sexually Transmitted Disease (STD) Clinic in Rome, Italy. Total HAV antibody (anti-HAV) was detected in 60.3% of homosexuals and 62.2% of heterosexuals. After adjustment for the confounding effects of age, years of schooling, number of sexual partners, use of condoms, and history of STD, homosexuals were not found to be at increased risk of previous HAV exposure than heterosexuals (OR 1.1; 95% CI 0.7-1.9). Independent predictors of the likelihood of anti-HAV seropositivity among homosexuals and heterosexuals were: age older than 35 years and positive syphilis serology which is likely a proxy of lifestyles that increase the risk of faecal-oral infections. These findings do not support a higher risk in homosexual men but could suggest a role for the vaccination of susceptible patients attending STD clinics.

Seroprevalence of anti-human parvovirus B19 antibodies in patients attending a centre for sexually transmitted diseases

The aim of this study was to establish the serological prevalence of anti-human Parvovirus B19 (HP-B19) antibodies in a group of 321 patients attending a Centre for Sexually Transmitted Diseases (STDs) and epidemiologically examine whether this virus may also be sexually transmitted. For this purpose, the serum prevalence of anti-HP-B19 evaluated in STD patients (39%) was compared with that of 164 healthy blood donors (10%, p < 0.001), using commercially available ELISA methods detecting the anti-VP1 reactivity of the sera. The same STD patients were also analyzed for serum reactivities against 4 STD-causing microorganisms, namely T. pallidum (TPHA), HBV (HBcAb), HCV (HCV-Ab) and HIV (HIV-Ab), to observe possible associations with the serum anti-HP-B19 reactivity. These tests were also carried out with commercially available kits. The results suggest that the serum anti-HP-B19 antibody prevalence in patients with STDs is increased, also independently of their intravenous drug addition and varies with the reactivity pattern determined. In addition, as expected for a STD, the anti-HP-B19 prevalence is increased in homobisexual patients compared with heterosexuals.

Risk of human immunodeficiency virus infection and genital ulcer disease among persons attending a sexually transmitted disease clinic in Italy

To assess the relative importance of ulcerative and non-ulcerative sexually transmitted disease in the transmission of HIV, a seroprevalence study was conducted on 2210 patients at the sexually transmitted diseases (STD) clinic of the S. Maria e S. Gallicano Hospital in Rome, between 1989 and 1994. Among male patients, by univariate analysis, strong predictors of HIV infection were homosexuality, sexual exposure to a HIV-positive partner, hepatitis B virus infection, and positive syphilis serology. An increased risk was estimated for patients with past genital herpes (odds ratio (OR) 3.86, 95% confidence intervals (CI) 0.40-18.2), and primary syphilis (OR 5.79, 95% CI 0.59-28.6). By multivariate analysis, a positive association was found with homosexuality (OR 6.9, 95% CI 2.9-16.5), and positive syphilis serology (OR 3.5, 95% CI 1.3-9.2). An adjusted OR of 2.41 was calculated for current and/or past genital herpes. These results, although not conclusive, suggest a role of ulcerative diseases as risk factors for prevalent HIV infection, and indicate that positive syphilis serology is an unbiased criterion for identifying individuals at increased risk of HIV infection.

Ranitidine bismuth citrate plus clarithromycin 7-day regimen is effective in eradicating Helicobacter pylori in patients with duodenal ulcer

BACKGROUND

No clinical study has been performed to-date to evaluate the efficacy of the dual therapy of ranitidine bismuth citrate (RBC) plus clarithromycin (C) 500 mg b.d. given for 7 days for the eradication of H. pylori.

AIM

To assess the eradication rates achieved by treatment with RBC 400 mg b.d. for 28 days combined with clarithromycin 500 mg b.d. for 7 days in H. pylori-positive duodenal ulcer patients.

METHODS

One hundred and twelve H. pylori-positive patients with endoscopically proven active duodenal ulcer were included in a multicentre, open, randomized trial. H. pylori infection was initially detected by CLO-test and histology on antral and corpus biopsies, and by 13C-urea breath test (UBT). Patients were included if at least two of the tests were positive for H. pylori infection. Patients were randomized to receive RBC 400 mg b.d. for 4 weeks combined with clarithromycin 500 mg b.d. for the first 7 days (Group A) or 14 days (Group B). A second endoscopy was performed at least 28 days after the end of therapy for the assessment of ulcer healing and H. pylori infection. Eradication was assumed if all the tests (CLO-test, histology and UBT) were negative for H. pylori.

RESULTS

Fifty patients in Group A and 55 in Group B were assessed for H. pylori eradication and ulcer healing. The eradication rates according to intention-to-treat analysis were 75% in Group A and 80% in Group B. Considering only those patients with evaluable data at least 28 days after the end of therapy, H. pylori eradication was achieved in 84% and 82% in Group A and B, respectively. No statistically significant difference in eradication was found between the two groups by Mantel-Haenszel test. Only one patient, in Group A, was withdrawn because of adverse events (epigastric pain and pruritus).

Risk factors for hepatitis B virus infection among homosexual men attending a sexually transmitted diseases clinic in Italy

Prevalence of and risk factors for hepatitis B virus (HBV) infection were determined among 252 homosexual men with no history of intravenous drug use (median age 33 years, range 18-77) treated at a sexually transmitted disease (STD) clinic in Rome. The overall prevalence of antibodies to HBV core antigen (anti-HBc) was 50.8%, a rate nearly nine times as high as the 5.8% found recently in a national sample of young male adults, aged 18-26 years, and twice as high as the 22% found in heterosexuals attending the same clinic over the same period of time. Multiple logistic regression analysis showed that the risk of anti-HBc positivity was independently associated with increasing age, five or more sexual partners in the previous year, positive HIV serology and positive syphilis serology. Lower level of schooling, lack of condom use, history of non-ulcerative STD, current or past history of genital herpes, and positive anti-HCV serology were not associated with anti-HBc positivity. These findings corroborate the importance of sexual transmission of HBV in homosexual men. Behavioural factors, such as multiple sexual partners, probably enhance the efficiency of this mode of HBV transmission.

Incidence and determinants of hepatitis C virus infection among individuals at risk of sexually transmitted diseases attending a human immunodeficiency virus type 1 testing program

BACKGROUND

The role of sexual transmission of hepatitis C virus (HCV) infection is still not completely understood, partly because of the lack of longitudinal studies among cohorts of HCV-negative individuals who engage in at-risk sexual behavior.

GOALS

To evaluate the incidence of HCV infection in a population at risk for human immunodeficiency virus type 1 (HIV-1) infection and other sexually transmitted diseases (STD) and to identify factors associated with HCV seroconversion.

STUDY DESIGN

A retrospective longitudinal study was carried out on a cohort of consecutive attendees of a voluntary HIV-1 testing and counseling program in a large STD center in Rome. All individuals undergoing at least two consecutive tests for HCV antibodies were enrolled. Clinical data and information on individual behavior were collected for all study participants.

RESULTS

Between June, 1992 and December, 1994, a total of 709 individuals (12 intravenous drug users [IDU], 244 homosexuals, and 453 heterosexual non-IDUs), initially negative for HCV antibody, were tested more than once. Among these individuals, 15 HCV seroconversions occurred. The average follow-up time was 1.25 person/years (p/y) for an incidence rate of 1.69 per 100 p/y. The incidence rates by exposure category were 39.30 per 100 p/y among IDUs, 1.37 per 100 p/y among homosexual men, and 0.97 per 100 p/y among heterosexual non-IDUs. Excluding IDUs, of the 697 STD clinic attendees engaging in at-risk sexual behavior, HIV-1-positive status tended to be associated with HCV seroconversion (relative hazard = 5.48; 95% confidence interval = 0.85-35.40). The HCV crude incidence rates among HIV-1-infected patients at enrollment was 11.5%, 4.2%, and 2.4% in those with severe, moderate, and mild levels of immunosuppression, respectively (chi-square for trend = 2.38, P = 0.1).

CONCLUSIONS

In this cohort, HCV infection was confirmed to be strongly associated with intravenous drug use. Nonetheless, the occurrence of two thirds of the total HCV seroconversions in non-IDU individuals engaging in at-risk behavior suggests a role of sexual practices in the transmission of the infection. Among non-IDU individuals, the risk for development of HCV infection tended to increase in those who were HIV-1 infected.