Proactive therapeutic monitoring of dalbavancin concentrations in the long-term management of chronic osteoarticular/periprosthetic joint infections

Here, we describe the use of proactive therapeutic drug monitoring (TDM) to individualize the optimal timing of drug injections in 16 adult patients with chronic osteoarticular infections receiving a median of 7 injections of dalbavancin (up to 12 injections in 15 months). Dalbavancin injections were repeated at medians of 39-47 days, with infusion intervals ranging from 26 to 69 days. TDM can facilitates a precise, targeted use of dalbavancin for infections requiring prolonged treatments.

Clinical and atopic features of patients with primary eosinophilic colitis: an Italian multicentre study

Eosinophilic colitis (EC) is the rarest among primary eosinophilic gastrointestinal disorders (EGID). EC is underdiagnosed due to its blurred and proteiform clinical manifestations. To explore the clinical and atopic characteristic of EC adult patients, the diagnostic delay, and relapse-associated factors, by comparison with patients with eosinophilic esophagitis (EoE) and irritable bowel syndrome (IBS). EC patients followed-up at four clinics were included, and clinical, histopathological, and laboratory data were retrieved. As control groups, age-matched patients with EoE and IBS were recruited. Allergy tests included skin prick test and serum specific IgE. Diagnostic delay was assessed. Overall, data from 73 patients were retrieved, including 40 with EC (median age 39 years IQR 22.5-59, F:M 2.1:1), 12 with EoE (F:M ratio: 1:5), and 21 with IBS (F:M ratio: 1:0.9). The most common features in EC patients were female sex (67.5%), atopy (77.5%), abdominal pain/distention (70%), diarrhoea (77.5%), and faecal calprotectin elevation (22.5%). Blood eosinophils were elevated in EoE, but not in EC (p < 0.001), while ECP did not differ across the three groups (p = 0.4). The frequency of allergen sensitization reached 25% of patients. Several frequent pan-allergens for this region were present. The overall diagnostic delay was 10 months (IQR 4-15). Factors contributing to a greater diagnostic delay were atopy, weight loss, and a previous misdiagnosis. EC is mostly a diagnosis of exclusion, burdened by a substantial diagnostic delay. In female patients the presence of allergen sensitization, abdominal symptoms and faecal calprotectin elevation should raise the suspicion of EC.

Haematological sequelae in the post-acute phase of symptomatic SARS-CoV-2 infection

Many patients surviving SARS-CoV-2 infection suffer from long-term symptoms (long COVID or post COVID) such as shortness of breath, fatigue, loss of taste or smell and cognitive deterioration. However, few data are available concerning blood cell counts and haematological parameters during the post-COVID period. We analysed haematological data from 83 patients previously admitted to the internal medicine unit of our institution because of symptomatic SARS-CoV-2 infection; all data were obtained within 1-12 months from disease onset. A control group of 70 apparently healthy, age- and sex-matched COVID-19 negative individuals was assessed for comparison. Blood cell counts improved in the post-COVID period, but 81% of patients had persistent abnormalities, compared with 50% in the control group, p < 0.001. Most common haematological findings included anaemia (40%), reduced lymphocyte (43%) or eosinophil counts (38%) and low IgM memory B cells and correlated with advanced age, number of chronic comorbidities, female gender, altered renal function, reduced baseline Hb and procalcitonin concentrations and increased RDW. Data on lymphocytes and IgM memory B cells show that impaired immune responses may persist for up to one year in the post-COVID period, possibly contributing to long-term symptoms, especially in female patients.

Therapeutic Drug Monitoring of Dalbavancin in Real Life: A Two-Year Experience

Dalbavancin is a long-acting lipoglycopeptide that is registered for the treatment of acute bacterial skin and skin structure infections, and it is also increasingly used for infections that require prolonged antibiotic treatment. Here, we present the results from the first 2 years of a service set up in December 2021 for the therapeutic drug monitoring (TDM) of dalbavancin in clinical settings. In particular, we compared the trough concentration (Cmin) to maximum concentration (Cmax) in patients with osteoarticular infections receiving prolonged treatment with dalbavancin. Log-linear regression models were used to estimate the timing of dalbavancin administration with the goal of maintaining Cmin concentrations of >8 mg/L in the two TDM-based strategies. From December 2021 to November 2023, 366 TDMs of dalbavancin from 81 patients were performed. The Cmin and Cmax concentrations of dalbavancin ranged from 4.1 to 70.5 mg/L and from 74.9 to 995.6 mg/L, respectively. With log-linear regression models, we estimated that each injection should be administered every 42-48 days to maintain the Cmin concentrations. Out of the 81 patients, 37 received at least three doses of dalbavancin for the treatment of osteoarticular infections. Despite there being no significant differences in the days of dalbavancin treatment (130 ± 97 versus 106 ± 102 days), the patients in the Cmax-based TDM group received a significantly lower number of dalbavancin injections (5.2 ± 1.8 versus 7.3 ± 2.6 injections, p = 0.005), and they were administered over a longer period of time (40 ± 10 versus 29 ± 14 days, p = 0.013) than in the Cmin-based TDM group. In conclusion, Cmax-based TDM was associated with a significant reduction in the inter-individual variability of dalbavancin concentrations and lower drug dosing frequency than those of Cmin-based TDM. This approach could, therefore, favor a more rational and targeted use of dalbavancin in patients requiring prolonged treatment.

Immunotherapy with Pru p 3 for food allergy to peach and non-specific lipid transfer protein: a systematic review

BACKGROUND

Non-specific lipid-transfer protein (nsLTP) is a pan-allergen in the plant world, and a cause of significant concern as food allergen in the Mediterranean area, due to its general heat- and acid-resistance and hence the risk of severe allergic reactions. Pru p 3, the peach nsLTP, is considered the primary sensitizer to this allergen family and this allergy is usually persistent. Allergen-free diet and acute treatment of manifestations are the main recognized management goals in food allergy.

MAIN TEXT

The role of immunotherapy for treating food allergy in adult patients is controversial, but immunotherapy for Pru p 3 could potentially represent a relevant therapeutic strategy. We systematically searched databases for studies assessing the role of immunotherapy Pru p 3 in food allergy. Overall, nine studies were included. Immunotherapy with Pru p 3 appears to be effective and with a good safety profile in both peach and LTP allergy for some foods, such as peanut, in both RCT and real-life studies.

CONCLUSIONS

Immunotherapy with Pru p 3 is a possible treatment option for food allergy to the peach LTP in the Mediterranean area, although at present have not reached routinary clinical practice. Larger studies are needed to confirm these findings and identify predictive biomarkers.

Dietary Strategies in Adult Patients with Eosinophilic Esophagitis: A State-of-the-Art Review

Allergen-free diets are a specific and effective anti-inflammatory therapy for eosinophilic esophagitis. They should be carried out by a multidisciplinary team to reduce side effects and improve adherence. According to recent guidelines and expert opinions, empirical diets with a reduced number of eliminated food categories and a step-up approach are the most encouraged strategy to reduce the number of endoscopies to identify food trigger(s) and maximize clinical results and adherence. Despite the fact that allergy testing-based diets are not recommended at a population level, geographical sensitization patterns may play a role in some patients in specific areas, such as in Southern and Central Europe.

Role of IgM Memory B Cells and Spleen Function in COVID-19

IgM memory B cells, are a peculiar subset of memory B cells, which probably originates in the spleen and outside germinal centers and provide a rapid line of defence against mucosal infections. Their role in counteracting COVID-19 is still elusive but, recent evidence, mainly boosted by studies on spleen function/involvement in COVID-19, seems to support the notion that this subset of memory B cells could exert a protective role against this virus, along with other coronaviruses, particularly in the acute setting of the infection, as outlined by worst clinical outcomes observed in unvaccinated patients with impaired IgM B memory response and spleen function. Herein we critically summarise the current landscape of studies on IgM memory B cells, focusing on the clinical impact of their depletion, by comparing the COVID-19-related splenic dysfunction with other hypo- and asplenic conditions and by adding recent data on follow-up studies and postulate a mechanistic explanation for their reduced numbers. The early detection of an impaired IgM memory B cell response in patients with COVID-19 may contribute to their improved care through different strategies, such as through tailored vaccine strategies, prompt hospital admission and/or administration of anti-infective treatments, thus resulting in an better prognosis, although at present management algorithms are still unavailable. Moreover, further studies with longer follow-up are needed to assess the evolution of COVID-19-associated/exacerbated immune deficit.

Primary eosinophilic gastrointestinal disorders and allergy: Clinical and therapeutic implications

Primary eosinophilic gastrointestinal disorders (EGID) are increasingly prevalent, immune‐mediated, chronic conditions which primarily affect pediatric and young adult patients, leading to substantial disease burden, and poor quality of life. EGID may either involve single portions of the gastrointestinal tract (i.e., esophagus, stomach, small bowel, and colon) or a combination. Their strong association with allergic disorders has been recently recognized, and although their shared pathophysiological basis remains partly elusive, this feature greatly impacts the diagnostic and treatment work‐up. We herein critically discuss the current knowledge on the association of EGID and allergic disorders, including atopic dermatitis, allergic rhinitis, allergic asthma, and food or drug allergy. In particular, we reviewed the literature focusing on their epidemiology, pathophysiological basis and mechanisms, and diagnostic strategies. Finally, we discuss the currently ongoing clinical trials targeting EGID and allergic diseases, including, among others the monoclonal antibodies dupilumab, mepolizumab, benralizumab, and lirentelimab.

Diagnostic delay and misdiagnosis in eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EoE) may lead to severe complications if not promptly recognised.

AIMS

To assess the diagnostic delay in patients with EoE and to explore its risk factors.

METHODS

EoE patients followed-up at eight clinics were included via retrospective chart review. Diagnostic delay was estimated as the time lapse occurring between the appearance of the first likely symptoms indicative of EoE and the final diagnosis. Patient-dependent and physician-dependent diagnostic delays were assessed. Multivariable regression models were computed.

RESULTS

261 patients with EoE (mean age 34±14 years; M:F ratio=3:1) were included. The median overall diagnostic delay was 36 months (IQR 12-88), while patient- and physician-dependent diagnostic delays were 18 months (IQR 5-49) and 6 months (IQR 1-24). Patient-dependent delay was greater compared to physician-dependent delay (95% CI 5.1-19.3, p<0.001). A previous misdiagnosis was formulated in 109 cases (41.8%; gastro-oesophageal reflux disease in 67 patients, 25.7%). The variables significantly associated with greater overall diagnostic delay were being a non-smoker, >1 episode of food impaction, previous endoscopy with no biopsies, regurgitation, and ≥2 assessing physicians. Being single was significantly associated with lower overall and patient-dependent diagnostic delay.

CONCLUSION

EoE is burdened by substantial diagnostic delay, depending on both patient-related and physician-related factors.

Allergic manifestations in autoimmune gastrointestinal disorders

Allergic disorders target a young population, are increasing in both incidence and prevalence and are associated with significant disease burden. They result from the complex interplay between (epi)genetic and environmental factors, resulting in a Th2 inflammatory process targeting the epithelium of the respiratory tract (allergic rhinitis and asthma), skin (atopic dermatitis), and gastrointestinal tract (food allergy). Although the exact pathogenic mechanisms remain elusive, an altered immune system response in the gut is increasingly recognized as a relevant step. Allergic and gastrointestinal autoimmune disorders share several epidemiological, pathogenic and risk factors and several treatment modalities. Here we revise the current literature and show that allergic disorders are highly prevalent in gastrointestinal autoimmune diseases, including celiac disease, inflammatory bowel disease, autoimmune pancreatitis, and autoimmune cholangiopathies. No data are available for some autoimmune diseases, such as autoimmune gastritis and autoimmune enteropathy. To ensure the comprehensive care of patients with autoimmune gastrointestinal disorders, along with disease-specific factors, the presence of allergic disorders should be evaluated and treated when present, possibly targeting shared molecular pathways. Future studies are needed to define the exact pathogenic mechanisms underpinning the association between allergic and autoimmune diseases of the gastrointestinal tract.

Anemia in patients with Covid-19: pathogenesis and clinical significance

COVID-19 patients typically present with lower airway disease, although involvement of other organ systems is usually the rule. Hematological manifestations such as thrombocytopenia and reduced lymphocyte and eosinophil numbers are highly prevalent in COVID-19 and have prognostic significance. Few data, however, are available about the prevalence and significance of anemia in COVID-19. In an observational study, we investigated the prevalence, pathogenesis and clinical significance of anemia among 206 patients with COVID-19 at the time of their hospitalization in an Internal Medicine unit. The prevalence of anemia was 61% in COVID-19, compared with 45% in a control group of 71 patients with clinical and laboratory findings suggestive of COVID-19, but nasopharyngeal swab tests negative for SARS-CoV-2 RNA (p = 0.022). Mortality was higher in SARS-CoV-2 positive patients. In COVID-19, females had lower hemoglobin concentration than males and a higher prevalence of moderate/severe anemia (25% versus 13%, p = 0.032). In most cases, anemia was mild and due to inflammation, sometimes associated with iron and/or vitamin deficiencies. Determinants of hemoglobin concentration included: erythrocyte sedimentation rate, serum cholinesterase, ferritin and protein concentrations and number of chronic diseases affecting each patient. Hemoglobin concentration was not related to overall survival that was, on the contrary, influenced by red blood cell distribution width, age, lactate dehydrogenase and the ratio of arterial partial oxygen pressure to inspired oxygen fraction. In conclusion, our results highlight anemia as a common manifestation in COVID-19. Although anemia does not directly influence mortality, it usually affects elderly, frail patients and can negatively influence their quality of life.

Depletion of circulating IgM memory B cells predicts unfavourable outcome in COVID-19

Impaired immune responses have been hypothesised to be a possible trigger of unfavourable outcomes in coronavirus disease 2019 (COVID-19). We aimed to characterise IgM memory B cells in patients with COVID-19 admitted to an internal medicine ward in Northern Italy. Overall, 66 COVID-19 patients (mean age 74 ± 16.6 years; 29 females) were enrolled. Three patients (4.5%; 1 female) had been splenectomised and were excluded from further analyses. Fifty-five patients (87.3%) had IgM memory B cell depletion, and 18 (28.6%) died during hospitalisation (cumulative incidence rate 9.26/100 person-week; 5.8-14.7 95% CI). All patients who died had IgM memory B cell depletion. A superimposed infection was found in 6 patients (9.5%), all of them having IgM memory B cell depletion (cumulative incidence rate 3.08/100 person-week; 1.3-6.8 95% CI). At bivariable analyses, older age, sex, number of comorbidities, and peripheral blood lymphocyte count < 1500/µl were not correlated with IgM memory B cell depletion. A discrete-to-marked reduction of the B-cell compartment was also noticed in autoptic spleen specimens of two COVID-19 patients. We conclude that IgM memory B cells are commonly depleted in COVID-19 patients and this correlates with increased mortality and superimposed infections.

A case of extremely prolonged viral shedding: Could cell cultures be a diagnostic tool to drive COVID-19 patient discharge?

This study addressed the case of a patient with prolonged COVID-19 viral shedding, reported by Real-Time PCR, until 71 days from symptom onset. However, viral culture received negative results after 30 days from symptom onset. Therefore, viral culture may be a worthwhile test for patients requiring discharge, in particular for those presenting prolonged viral shedding.

A proposal of a "ready to use" COVID-19 control strategy in an Oncology ward: Utopia or reality?

•

During COVID-19 pandemic cancer patients are a vulnerable category.

•

Few data about control infection strategy to ensure a COVID-19 free Oncology ward.

•

The essence of our protocol: triage, risk zones, traffic control and surveillance.

•

This strategy could be a practical contribution to control nosocomial COVID-19.

The Coronavirus Disease-2019 (COVID-19) pandemic is spreading in Italy and Lombardy is one of the most affected region. Cancer patients are higher risk of complication from COVID-19 complications; therefore they should be protected from contagion while still ensuring access to cancer care.

The aim of this article is to suggest a strategy to reorganize hospital spaces and Healthcare Professionals (HCPs) staff in order to avoid COVID-19 nosocomial infection in an Oncology ward. SARS-CoV-2 is primarily transmitted through respiratory droplets and by contact. We speculated that precautions against droplet and contact transmission should be the proper way to preserve ward from COVID-19.

The essence of our protocol involves: triage outside of the ward, identification of risk zones, traffic control, surveillance of all the involved subjects. Whoever attends the ward must follow the general risk prevention and mitigation measures. The application of this practical strategy can contribute to breaking the cycle of community-hospital-community transmission.

Impact of COVID-19 on liver function: results from an internal medicine unit in Northern Italy

Little is known regarding coronavirus disease 2019 (COVID-19) clinical spectrum in non-Asian populations. We herein describe the impact of COVID-19 on liver function in 100 COVID-19 consecutive patients (median age 70 years, range 25-97; 79 males) who were admitted to our internal medicine unit in March 2020. We retrospectively assessed liver function tests, taking into account demographic characteristics and clinical outcome. A patient was considered as having liver injury when alanine aminotransferase (ALT) was > 50 mU/ml, gamma-glutamyl transpeptidase (GGT) > 50 mU/ml, or total bilirubin > 1.1 mg/dl. Spearman correlation coefficient for laboratory data and bivariable analysis for mortality and/or need for intensive care were assessed. A minority of patients (18.6%) were obese, and most patients were non- or moderate-drinkers (88.5%). Liver function tests were altered in 62.4% of patients, and improved during follow-up. None of the seven patients with known chronic liver disease had liver decompensation. Only one patient developed acute liver failure. In patients with altered liver function tests, PaO2/FiO2 < 200 was associated with greater mortality and need for intensive care (HR 2.34, 95% CI 1.07-5.11, p = 0.033). To conclude, a high prevalence of altered liver function tests was noticed in Italian patients with COVID-19, and this was associated with worse outcomes when developing severe acute respiratory distress syndrome.

Off-label use of tocilizumab for the treatment of SARS-CoV-2 pneumonia in Milan, Italy

BACKGROUND

Tocilizumab, a humanized monoclonal antibody, targets IL-6 receptors blocking downstream pro-inflammatory effects of IL-6. In preliminary reports it was suggested to be beneficial in patients with severe COVID-19.

METHODS

In this open-label prospective study we describe clinical characteristics and outcome of 51 patients hospitalized with confirmed and severe COVID-19 pneumonia treated with tocilizumab intravenously. All patients had elevated IL-6 plasma level (>40 pg/mL) and oxygen saturation <93% in ambient air. Clinical outcomes, oxygen support, laboratory data and adverse events were collected over a follow-up of 30 days.

RESULTS

Forty-five patients (88%) were on high-flow oxygen supplementation, six of whom with invasive ventilation. From baseline to day 7 after tocilizumab we observed a dramatic drop of body temperature and CRP value with a significant increase in lymphocyte count (p<0.001). Over a median follow-up time of 34 days from tocilizumab, 34 patients (67%) showed an improvement in their clinical severity class; 31 were discharged; 17 (33%) showed a worsening of their clinical status, of these 14 died (27%). The mortality rate was significantly associated with mechanical ventilation at baseline (83.3% vs 20% of patients on non-invasive oxygen support; p=0.0001). The most frequent side effects were an increase of hepatic enzymes (29%), thrombocytopenia (14%), and serious bacterial and fungal infections (27%).

CONCLUSION

Tocilizumab exerts a rapidly beneficial effect on fever and inflammatory markers, although no significant impact on the clinical outcome can be inferred by our results. Critically ill patients seem to have a high risk of serious infections with this drug.

Lyme borreliosis incidence in Lombardy, Italy (2000-2015): Spatiotemporal analysis and environmental risk factors

Lyme borreliosis cases have been reported from Lombardy in northern Italy, where Ixodes ricinus is the main vector of Borrelia burgdorferi sensu lato. However, spatial and temporal variation in the incidence of Lyme borreliosis is not well understood. In the present study, based on new notified cases of Lyme borreliosis from 2000 to 2015, an average of 1.24 new cases per million residents per year was documented. New cases, georeferenced at the municipal level, were analyzed by retrospective space-time analysis (using SaTScan v. 9.3.1); and land cover, extrapolated from a Corine Land Cover dataset (using QGIS 2.8.1), was used to implement an environmental risk factor analysis. Firstly, a temporal high-risk cluster was detected in Lombardy: the relative risk of Lyme borreliosis was 3.73 times higher during 2008-2015 compared with the entire study period. Moreover, in a spatiotemporal high-risk cluster with a circular base, land cover consisting of wildland-urban interface, meadow, forest and meadow-forest transition were significantly higher compared to low-risk areas. Results of the present study demonstrate that the incidence of Lyme borreliosis is increasing in Lombardy and that environmental conditions are suitable for I. ricinus ticks infected with B. burgdorferi s.l.: citizens and health systems should be aware of Lyme borreliosis to reduce tick bites with personal protective behaviors and to avoid misdiagnosis, particularly within the area including the observed high-risk cluster. Economic resources should be invested to inform about methods to prevent tick bites, how to check people and pets after frequenting risk areas, and ways of removing the biting ticks when they are found.

Occurrence of Lyme disease infection in a non-endemic area in Northern Italy

BACKGROUND

In Italy, the incidence of human tick-borne disease has increased over the last decades. Since 2015 a multidisciplinary group has been established in Sacco Hospital for the management of the patients affected by Lyme disease (LD). A retrospective evaluation (2015-2017) was performed for LD in non-endemic areas.

METHODS

Retrospective analysis of all 1000 samples for 800 patients screened for LD antibodies at the Sacco Hospital in 3 years (2015-2017). Clinical and epidemiological data were collected and compared with the serological results.

RESULTS

Among the 800 patients screened, 134 of them were diagnosed with borreliosis during 2015 (37 cases), 2016 (31 cases) and 2017 (66 cases). Localized LD was diagnosed 100 out of 134 cases (69%): in most of them (N.=63) erythema migrans has been documented; in 37 out of 100 it was not possible to detect it. In only three cases, patients complained of different clinical symptoms such as headache, arm and facial pain respectively. 23 out of 134 cases (16%) showed a persistence of serological positivity and symptoms with osteomuscular involvement and fatigue, despite the therapy (late LD). In that same study 11 out of 134 patients (7%) received a diagnosis of neuroborreliosis.

CONCLUSIONS

Our data reported a high percentage of LD infection (19%) in a non-endemic area. The definition of a Multidisciplinary Working Group and a clinical care pathway allowed a better clinical management of LD cases treated in Sacco Hospital, Milan.

Linezolid plasma concentrations and occurrence of drug-related haematological toxicity in patients with gram-positive infections

Retrospective studies have documented a significant association between linezolid (LNZ) plasma concentrations and drug-related haematological toxicity. However, the safe upper threshold level for LNZ plasma trough concentrations (Cmin values) has not been defined with certainty. A prospective observational study was performed aimed at comparing LNZ Cmin values in patients developing drug-related side effects with those measured in patients not experiencing LNZ toxicity. LNZ Cmin values were measured from the first week after starting therapy and were repeated periodically up to the end of treatment. Fifty patients, for a total of 210 LNZ Cmin evaluations, were considered. All patients (n=9) who developed drug-related haematological toxicity also had significantly higher plasma LNZ Cmin values during the first week of therapy (9.0±6.4 mg/L vs. 4.9±3.7 mg/L; P<0.01) and thereafter (9.3±5.4 mg/L vs. 4.4±3.4 mg/L; P<0.01). The significant association between LNZ plasma concentrations and haematological toxicity was also confirmed by multivariate logistic regression analysis including age, serum creatinine and concomitant medications as independent variables. A causal relationship between LNZ concentrations and the risk of developing drug-related haematological toxicity was observed. Accordingly, application of therapeutic drug monitoring may improve the safety outcome of patients receiving LNZ therapy.

Isolation of endophytic streptomyces strains from surface-sterilized roots

When the roots of 28 plant species were surface sterilized and incubated on agar medium, endophytic actinomycetes in the root cortex were observed by direct microscopic observation and pure culture techniques.

Interferon-gamma releasing assay versus tuberculin skin testing for latent tuberculosis infection in targeted screening programs for high risk immigrants

BACKGROUND

Recent immigrants from developing countries (<2 years since immigration) are at very high risk of active TB disease due to reactivation of latent infections acquired in the country of origin. In industrialized low-incidence TB countries targeted testing programs for high risk groups could allow the detection of latently infected persons who would likely benefit from a course of preventive treatment. In this study we evaluated the tuberculin skin test (TST) and interferon-gamma enzyme-linked immunosorbent assay (QuantiFERON TB-gold in tube, QFT-IT) strategies for TB infection screening programs in recent immigrants from highly endemic countries.

PATIENTS AND METHODS

This is a prospective cross-sectional study. Paired tests performed in 1,130 immigrants attending an outpatient ward, between 2005 and 2007 for any health problem were evaluated by intention-to-treat (ITT) and per-protocol (PP) analysis for efficiency and efficacy of screening program.

RESULTS

Positive TST and QFT-IT were observed in 36.04 versus 29.82% (ITT) and in 45.27 versus 30.22% (PP) respectively. A higher drop-out rate was observed for TST (20.35 vs. 1.33%) (p < 0.0001). Second level assessment was accepted by half of the TST positive patients. Overall agreement rate between 887 paired tests was fair (k = 0.38). Higher k values were observed for higher TB prevalence rate in the country of origin (k = 0.43), for TST induration diameters >20 mM (k = 0.47), in subjects aged 40-50 years (k = 0.41) and in unvaccinated persons (k = 0.40). In a multiple logistic regression model continent of origin, class of TB prevalence in the country of origin and contacts with TB patients were found to be significantly associated with the probability of TST and QFT-IT positive result. Low education levels were associated only to an increased risk of TST positive results.

CONCLUSIONS

The drawback of the TST screening strategy in recent immigrants from highly endemic countries is due to low sensitivity/specificity of the test and to high drop-out rate with an overall significant lowering in strategy efficacy/efficiency. The higher QFT-IT specificity prevents unnecessary overload of the health care system and, although more expensive, might represent a cost-effective alternative to TST in targeted screening programs directed to high risk populations.

Antiviral Efficacy and Genotypic Resistance Patterns of Combination Therapy with Stavudine/Tenofovir in Highly Active Antiretroviral Therapy Experienced Patients

Objectives

To evaluate antiviral efficacy of stavudine/tenofovir (d4T/TDF) backbone combination in late-line antiretroviral therapy, and to assess clinical and virological determinants of treatment success.

Design

Multicentric retrospective analysis on patients starting d4T/TDF after highly active antiretroviral therapy (HAART) failure.

Methods

The primary endpoint was the change in plasma HIV-1 RNA from the baseline (time of d4T/TDF initiation) to 6 months of therapy; secondary endpoint was the risk of virological failure.

Results

Among 172 patients included, a mean change in HIV-1 RNA of -1.69 (+1.23) and -1.53 (+1.43) log10 cp/ml was observed respectively at weeks 24 and 48 after starting d4T/TDF combination. Any single type-1 thymidine analogue mutation (TAM; M41L, L210W, T215Y) had a negative effort on the change in HIV RNA at 6 months, whereas among type-2 TAMs (D67N, K70R, K219Q), only D67N showed a trend for a negative effect. Presence of M184V mutation was related with a greater reduction in HIV RNA during d4T/TDF exposure. The risk of virological failure at 6 months after d4T/TDF starting was 22%. Type-1 TAMs were associated with a greater risk of failure (adjusted hazard ratio [HR]=1.65; 95% confidence interval [CI] 1.19–2.29). Conversely, M184V showed a protective effect. In 17 genotypic tests available at failure, no K65R mutation was detected, whereas a trend for an increasing prevalence of d4T-associated mutations was found.

Conclusions

Combining TDF with a thymidine analogue as d4T may be effective as component of antiretroviral rescue regimens in HIV-infected patients with previous exposure to nucleoside analogue reverse transcriptase inhibitor. Previous selection of type-1 TAMs induces a detrimental effect over virological response.

Antiviral efficacy and genotypic resistance patterns of combination therapy with stavudine/tenofovir in highly active antiretroviral therapy experienced patients

OBJECTIVES

To evaluate antiviral efficacy of stavudine/tenofovir (d4T/TDF) backbone combination in late-line antiretroviral therapy, and to assess clinical and virological determinants of treatment success.

DESIGN

Multicentric retrospective analysis on patients starting d4T/TDF after highly active antiretroviral therapy (HAART) failure.

METHODS

The primary endpoint was the change in plasma HIV-1 RNA from the baseline (time of d4T/TDF initiation) to 6 months of therapy; secondary endpoint was the risk of virological failure.

RESULTS

Among 172 patients included, a mean change in HIV-1 RNA of -1.69 (+1.23) and -1.53 (+1.43) log10 cp/ml was observed respectively at weeks 24 and 48 after starting d4T/TDF combination. Any single type-1 thymidine analogue mutation (TAM; M41L, L210W, T215Y) had a negative effort on the change in HIV RNA at 6 months, whereas among type-2 TAMs (D67N, K70R, K219Q), only D67N showed a trend for a negative effect. Presence of M184V mutation was related with a greater reduction in HIV RNA during d4T/TDF exposure. The risk of virological failure at 6 months after d4T/TDF starting was 22%. Type-1 TAMs were associated with a greater risk of failure (adjusted hazard ratio [HR]=1.65; 95% confidence interval [CI] 1.19-2.29). Conversely, M184V showed a protective effect. In 17 genotypic tests available at failure, no K65R mutation was detected, whereas a trend for an increasing prevalence of d4T-associated mutations was found.

CONCLUSIONS

Combining TDF with a thymidine analogue as d4T may be effective as component of antiretroviral rescue regimens in HIV-infected patients with previous exposure to nucleoside analogue reverse transcriptase inhibitor. Previous selection of type-1 TAMs induces a detrimental effect over virological response.

Evolution of HVR-1 Quasispecies after 1-Year Treatment in HIV/HCV-Coinfected Patients According to the Pattern of Response to Highly Active Antiretroviral Therapy

Hepatitis C virus (HCV) variability is mainly attributed to the ability of the virus to respond to host immune pressure, acting as a driving force for the evolution of quasispecies. This study was aimed at studying the changes in HVR-1 heterogeneity and the evolution of HCV quasispecies in HIV/HCV-coinfected patients according to the pattern of response to highly active antiretroviral therapy (HAART).

Sixteen HIV/HCV-coinfected patients harbouring HCV genotype 1 and who had been on HAART for at least 1 year, 8 showing increasing CD4+T-cell counts (immunological responders) and 8 showing a stable or decreasing CD4+ T-cell counts (immunological non-responders), were selected from a prospective cohort study.

After 1 year of HAART, 11 patients showed HIV viral load <2.6 log10 cp/ml (virological responders), and 5 showed HIV viral load above this value (virological non-responders). Plasma samples, collected before starting therapy and after 1 year of HAART, underwent clonal sequence analysis for HVR-1 region of HCV. Non-synonymous/synonymous substitutions ratio (Ka/Ks), aminoacidic complexity (normalized Shannon entropy) and diversity (p-distance), were considered as parameters of quasispecies heterogeneity. After 1 year of HAART, heterogeneity of HVR-1 quasispecies significantly decreased in virological non-responders, whereas the heterogeneity tended to increase in virological responders. The differences in the evolution were less stringent, when considering immunological response. On the other hand, profound qualitative modifications of HVR-1 quasispecies were observed only in patients with both immunological and virological HAART response.

On the whole, these findings suggest that, in patients undergoing HAART, the extent of HCV variability and the evolution of HVR-1 quasispecies is influenced by the pattern of response to antiretroviral therapy.

Response to Haart and Gb Virus Type C Coinfection in a Cohort of Antiretroviral-Naive HIV-Infected Individuals

The prognostic role of GB virus type C (GBV-C) viraemia in HIV-infected subjects treated with highly active antiretroviral therapy (HAART) is still undefined, The aim of this analysis is to assess the relationship between GBV-C infection and response to antiretroviral therapy among HIV-infected subjects initiating HAART when antiretroviral-naive.

A prospective, observational study of 400 HIV-infected patients with measurements of GBV-C RNA, hepatitis C virus (HCV) antibodies and HCV RNA determined from plasma stored prior to HAART initiation, Time to virological (achieving HIV RNA ≤500 copies/ml) and immunological success (a CD4+ count increase of ≥200cells/μl), and the time to virological relapse (confirmed HIV RNA >500 copies/ml) were assessed by Kaplan-Meier methods and Cox proportional hazard regression model.

Of the subjects, 117 (29.3%) were GBV-C positive and, overall, 351 (87.8%) patients achieved virological success, After controlling for a number of confounders including HCV RNA, GBV-C viraemic patients experienced a significantly lower risk of HIV rebound than those who were GBV-C negative [relative hazard (RH)=0.56, 95% CI: 0.34–0.93, P=0.03], Conversely, the probability of achieving initial virological success or CD4+ count response after HAART did not differ between GBV-C-negative and -positive subjects, These results suggest that GBV-C coinfection may play a role in determining the rate of HIV rebound possibly by competing with HIV replication after HIV load has been successfully suppressed by HAART.

Variability in the Interpretation of Transmitted Genotypic HIV-1 Drug Resistance and Prediction of Virological Outcomes of the Initial Haart by Distinct Systems

High level HIV-1 drug resistance in recently infected treatment-naive individuals correlates with sub-optimal virological responses to highly active antiretroviral therapy (HAART). To determine whether genotypic HIV-1 drug resistance in chronic naive patients, as interpreted by various systems, could predict the virological outcomes of HAART, isolates from patients enrolled in a prospective observational cohort (ICoNA) prior to treatment start were genotyped. Genotypic susceptibility scores (GSS) assigned to the initial HAART regimens using the interpretations of pre-therapy resistance mutations by 13 systems were related to virological outcomes. Of 415 patients, 42 (10%) had at least one major resistance mutation. According to the different interpretations, 1.9–20.5% of patients had some level of resistance to at least one drug in the initial regimen. In multivariable analysis, GSS from two systems significantly predicted the time to virological success: Rega 5.5, for each unit increase in GSS adjusted relative hazard (RH) 1.86 [95% confidence intervals (95% CI): 1.15–3.02] and hivresistanceWeb v3, RH 1.87 (95% CI: 1.00–3.48). With three other systems, GSS showed a trend towards a significant prediction of success: Retrogram 1.6, RH 2.33 (95% CI: 0.98–5.53), Menéndez 2002, RH 2.36 (95% CI: 0.97–5.72) and Stanford hivdb, RH 2.06 (95% CI: 0.94–4.49). Genotypic resistance testing coupled with adequate interpretation in chronic naive patients can usefully identify those at risk of sub-optimal virological response to HAART.

The Management of Hepatitis B Virus/HIV-1 Co-Infected Patients Starting Their First Haart Regimen. Treating Two Infections for the Price of One Drug?

We examined the impact of a lamivudine-containing highly active antiretroviral therapy (HAART) regimen on 164 hepatitis B virus/HIV co-infected individuals starting their first HAART. Lamivudine-treated patients (accounting for 73% of the study population) showed a significantly lower level of alanine aminotransferase over follow-up [–81.1 mU/ml mean difference; 95% confidence intervals (95% CI): –30.3; –131.7, P=0.003] and a significantly reduced risk of liver-related morbidity/mortality [Relative hazard (RH)=0.07; 95% CI: 0.01–0.38, P=0.002] than those starting a lamivudine sparing-regimen.

High prevalence of human T-lymphotropic virus type 1 (HTLV-1) in immigrant male-to-female transsexual sex workers with HIV-1 infection

Human T-lymphotropic virus type 1 and 2 (HTLV-1 and HTLV-2) infections in Europe are limited to intravenous drug users and migrants coming from areas in which they are endemic. A survey was undertaken of HTLV-1 and HTLV-2 infections in 393 recent immigrants: 167 HIV-1 positive subjects (including 52 male-to-female transsexual sex workers) and 226 pregnant HIV-1 negative women. The prevalence of HTLV-1 was 3.6% in the HIV-1 positive group and 0.9% in the HIV-1 negative group. The highest HTLV-1 prevalence in both groups was found in persons from Latin America, particularly those born in Peru (up to 26% in the HIV-1 positive group). All of the HIV-1/HTLV-1 co-infected individuals were male-to-female transsexual sex workers in whom the overall prevalence of HTLV-1 infection was 11.5%. HTLV-2 was only found in the HIV-1 positive group (prevalence 1.2%); all of the infected subjects were transsexual sex workers from Brazil (overall prevalence 6.4%). Phylogenetic analysis showed that all of the HTLV-1 isolates were of the cosmopolitan type, clustering with other strains circulating in the patients' birthplaces; the HTLV-2 isolates were of subtype 2a, and clustered significantly with other Brazilian strains. These results suggest the independent origin of each infection in the patient's birthplace. The data raise concerns about the further spread of HTLV infections mainly through the sexual route.

Combined surgery and cidofovir is an effective treatment for genital warts in HIV-infected patients

OBJECTIVE

To evaluate the efficacy of surgical-cidofovir (SCT), surgical (ST) and cidofovir (CT) treatment of genital warts in HIV-infected patients.

DESIGN

Open randomized prospective pilot study.

SETTING

Outpatients attending the sexually transmitted disease service of the II Dept of Infectious Diseases, L Sacco Hospital, Milan-Italy.

PATIENTS

Consenting HIV-positive patients with anal-genital warts recruited from January 2000 to March 2001.

INTERVENTIONS

Three treatment arms: surgical excision by electrocautery, topical 1% cidofovir-gel (5 days per week, maximum 6 weeks) and electrocautery-cidofovir treatment with 1% cidofovir-gel applied within 1 month of surgical treatment (5 days per week for 2 weeks).

MAIN OUTCOME MEASURES

Rate of wart clearance and time and rate of relapses within a 6-month follow-up period.

RESULTS

Complete response was achieved in 93.1% of 29 patients treated by ST, 76.2% of 26 treated by CT and in 100% of 19 patients treated by SCT (P = 0.0033). The relapse rate in 49 patients followed-up was 73.68% in ST, 35.29% in CT and 27.27% in SCT patients (P = 0.018). Median time to relapses in ST patients was 66 days (Kaplan-Meyer, P = 0.0012). Human papillomavirus DNA was cleared in 52.63% of 19 patients evaluated. The rate of clearance of high risk and low risk genotypes was 0% and 57.14% 25% and 50% 100% and 71.42% in ST, CT and SCT patients, respectively.

CONCLUSIONS

A combination of surgical and medical treatment was most effective in clearing lesions completely and in reducing the relapse rate. Human papillomavirus DNA clearance can be attributed to the antiviral effect of cidofovir and could explain the low relapse rate observed. Larger studies are required to determine the most appropriate medical treatment for viral eradication after surgery.

[Proposal for an informed consent form for hormonal replacement therapy in ambulatory care]

Hormonal Replacement Therapy (HRT) represents a valid therapeutic approach for menopausal symptoms and for the prevention of cardiovascular disease and osteoporosis. Nevertheless, an informed consent, after a complete information, must be obtained from the patient. This procedure is generally adopted in any medical activity, but the modality of the consent in the HRT administration is not well established (verbal or written?, timing of administration?). The authors propose an informed written consent model to be utilized in menopausal centers; this model synthetically informs about HRT benefits and risks and must be red and signed by the patient. The written consent should be explained through a verbal detailed discussion about it, during which the patient's comprehension must be assured. The informed consent procedure should be renewed every year in long term-users. The influence of the HRT informed consent in menopausal centers must be analyzed in particular as far as women compliance is concerned.

An expression system for the single-step production of recombinant human amidated calcitonin

Amidating mouse pituitary cells (AtT-20) have been engineered to secrete human calcitonin (hCT) in the fully active amidated form, without the need of additional enzymatic or chemical modifications. The 141-residue human calcitonin precursor has first been cloned in the eucaryotic expression vector pRc/RSV, and the resulting plasmid pRc/RSV/hCT introduced in AtT-20 cells. After transfection, 122 independent clones resistant to G-418 were selected and screened for calcitonin production using a competitive ELISA specifically designed to detect the amidated form of calcitonin. One of these clones was amplified and showed expression of 17 ng/ml of hCT, with a 70% increase in productivity after cAMP treatment. Calcitonin was partially purified from culture medium by two sequential steps of reverse-phase chromatography and characterized in terms of immunoreactivity and molecular weight by TOF-MALDI mass spectroscopy, which confirmed the intended chemical nature and the presence of the C-terminal amidated residue.

Production of soluble tumor necrosis factor receptor type I in Escherichia coli: optimization of the refolding yields by a microtiter dilution assay

In this study optimization of the soluble tumor necrosis factor receptor type I (sTNF-RI) refolding by the use of a micro-renaturation assay in 96-well microplates is described. Microplate wells were filled with buffers varying in pH and urea and substrate concentration. Denatured and reduced sTNF-RI was then rapidly diluted and allowed to refold for a variable time at different temperatures. The extent of renaturation was measured by a sandwich enzyme-linked immunosorbent assay (ELISA), based on the use of two monoclonal antibodies obtained against urinary sTNF-RI. Among about 100 different combinations tested, a maximum refolding yield of 21.5% has been obtained in 100 mM Tris, pH 8-8.5, 1 mM EDTA, 0.1% bovine serum albumin, 2 M urea, at a denatured protein concentration of 10 micrograms/ml and at 26 degrees C. Folded sTNF-RI was purified by batchwise immunoaffinity chromatography and its activity evaluated by immunological and biological assays. A good correlation was observed between the data obtained with different assays (biological assay, ligand-directed ELISA, and double-determinant sandwich ELISA) indicating that the refolded receptor has gained biological and immunological reactivity comparable to those of the soluble TNF-receptor type I expressed in eukaryotic cells.

Quantification of headache disability: a diagnostic-based approach

The quantification of the social and economic handicaps caused by headache is a complex problem, especially given the great variability of headache patients' clinical pictures. In the present study, 400 patients, consecutively admitted to Headache Centers in Pavia and Milan, were interviewed on the relationship between headache and their work and social activities, in order to evaluate their socioeconomic handicap due to headache. The analysis of the data primarily focused on attack-type headaches (migraine, cluster headache, and episodic tension-type headache) and chronic or daily headaches (chronic tension-type headache and migraine combined with tension-type headache). These latter types were often characterized by the daily use or abuse of analgesics. The overall profile which emerged from the study reveals relatively low levels of handicap or disability in work and social activities. These low levels can be mainly attributed to timely, and at times excessive, use of analgesics.

Identification of two forms (31-33 and 48 kD) of the urinary soluble p55 tumor necrosis factor receptor that are differentially N- and O-glycosylated

The structure and the activity of urinary soluble TNF receptor type 1 (sTNF-R1), isolated from the urine of normal individuals, has been characterized and compared with that of recombinant sTNF-R1 expressed in CHO cells and with that of a nonglycosylated form expressed in Escherichia coli. Urinary sTNF-R1 was resolved in a major band of 31-33 kD and in a 48 kD band (less than 5% of total) by reducing SDS-PAGE; CHO sTNF-R1 was resolved in two bands of 29 and 31 kD. All bands were recognized by various anti-sTNF-R1 antibodies as well as by TNF-alpha in western and ligand blotting assays. No cross-reaction was observed with anti-TNF-R2 antibodies. N- and O-glycosylation studies indicated that (1) the 29-31 kD recombinant form as well as the 31-33 kD urinary form are N-glycosylated; (2) the differences between the 29-31 and 31-33 kD recombinant and natural products are mainly related to differences in the N-linked sugar content; and (3) the 48 kD sTNF-R1 isolated from urine also contains O-linked sugars. The urinary sTNF-R1 antigen mixture was able to inhibit TNF-alpha cytotoxicity with a potency comparable to that of nonglycosylated E. coli sTNF-R1. At variance, urinary sTNF-R1 was able to inhibit TNF-beta sevenfold more efficiently than E. coli sTNF-R1. In conclusion, two subtypes of sTNF-R1 have been isolated from urine: a main N-glycosylated form of 31-33 kD and a N- and O-glycosylated form of 48 kD that appears to be a minor constituent of the urinary sTNF-R1 antigen.

Identification of differentially glycosylated forms of the soluble p75 tumor necrosis factor (TNF) receptor in human urine

Human urine is known to contain a 30 kDa soluble form of the p75-TNF receptor (sTNF-R2). In this work we have purified sTNF-R2 from the urine of normal subjects and further characterized its structure and activity. sTNF-R2 was resolved by reducing SDS-PAGE in a major band of 30 kDa, similar in size to the previously described urinary sTNFR2, and in a minor band of 45 kDa. "Western" blotting analysis with anti-TNF-R1 and anti-TNF-R2 antibodies showed that both bands were immunologically related to the membrane TNF-R2. Glycosylation studies indicated that the 30 kDa is N-glycosylated while the 45 kDa form is N- and O-glycosylated, and suggested that both forms contain terminally linked sialic acid that is differentially recognized by lectins. These results indicate that human urine contains, besides the 30 kDa form, a new form of 45 kDa characterized by different glycosylation type and degree.

Tumor necrosis factor (TNF) alpha quantification by ELISA and bioassay: effects of TNF alpha-soluble TNF receptor (p55) complex dissociation during assay incubations

It has been previously reported that different quantitative results can be obtained when TNF alpha is measured in biological fluids by bioassay and immunoassay. This is thought to be related to the presence of antigenic forms of TNF alpha that cannot be detected by bioassay, such as complexes with soluble receptors (sTNF-R) or TNF alpha monomers. In this work we have observed discrepancies between antigenic and bioactive TNF alpha even when we used a sandwich-ELISA, unable to detect TNF alpha monomers, based on antibodies that bind epitopes overlapping with the soluble-receptor binding site of TNF alpha. Moreover, we found that antigenic TNF alpha levels in the presence of p55-sTNF-R (sTNF-R1) measured by different immunoassays were variable, depending on the immunoreagents and incubation time. To investigate whether TNF alpha-soluble receptor complex dissociation occurring during assay incubations contributes to the variability of results, we studied the kinetics of TNF alpha-soluble receptor interactions and examined the effect of complex dissociation using different analytical systems. TNF alpha association (k(on)) and dissociation (koff) rate constants with sTNF-R1, measured by real-time biospecific interaction analysis, were 5.01 x 10(5) s-1 M-1 and 2.8 x 10(-4) s-1, corresponding to an equilibrium constant (Kd) of 0.59 nM and to a half life for these complexes of 38 min. Complex dissociation and differential changes in the TNF alpha-sTNF-R1 bound:free ratio, in different analytical systems, markedly affects TNF alpha quantification.

High yield expression and purification of human endothelin-1

A DNA construct encoding human big endothelin (Big ET) preceded by the factor Xa protease recognition site (Ile-Glu-Gly-Arg), fused in frame to the maltose binding protein sequence, has been introduced in DH5-alpha cells. The fusion product (MBP-Big ET) was expressed at a concentration close to 100 micrograms/ml of culture broth and constituted approximately 50% of the total protein content. Crude cell extracts containing the fusion product have been directly treated with trypsin under mild denaturing conditions in order to release big endothelin (1-37) from the adduct. Cleavage yield of the MBP-Big ET adduct was close to 70%. Big ET(1-37) was separated from unrelated peptides derived from the tryptic digest of the bacterial extract by affinity chromatography. The affinity column was prepared by immobilizing a protease resistant peptide ligand able to recognize Big ET with sufficient affinity, selectivity, and specificity. From the affinity step (recovery, 90%), recombinant Big ET(1-37) was obtained with a purity close to 80%. The affinity-purified recombinant product was then digested with alpha-chymotrypsin in order to release endothelin (1-21), which was then purified by RP-HPLC. With this two-step purification protocol, 3 micrograms of endothelin was recovered from 1 ml of bacterial broth, with a purity close to 95%.

Identification of hydropathically complementary putative contact sequences within epidermal growth factor (EGF) and the EGF receptor

Hydropathic complementariness (HC) has been proposed as a novel molecular recognition code for how two proteins can recognize one other and thus form a reversible complex. If a protein contains a segment of a few amino acid residues that is surface-exposed, plus in extended conformation, plus composed of residues whose hydropathy pattern is opposite to that of a correspondingly sized segment on the respective other protein, this protein may bind to the other one through such a segment of HC (1). In order to identify in a pair of proteins sequences of HC we have developed the program PUTATIVE SITES SEARCHER (PSS-1) (2), a name that alludes to the possibility that such a segment of HC could represent a putative contact "site". Here we describe the application of PSS-1 to the study of human epidermal growth factor (EGF) and human EGF receptor (EGF-R). Six segments of HC were identified, two of which, designated a and b, fall exactly into experimentally verified contact regions on EGF as well as on EGF-R. Site a consists of residues 25.AEIYMCV.19 of EGF ("half site" aEGF) and of residues 331.NIKHFKN.337 of the EGF-R ("half site" aEGF-R); site b consists of residues 34.VCNCAY.29 of EGF and residues 365.PQELDI.370 of the EGF-R. Most interestingly, both half sites aEGF and bEGF localize in loop B of hEGF which is recognized as being essential for receptor binding. Similar is true for the half sites aEGF-R and bEGF-R that localize in subdomain III (residues 314-445) of the extracellular part of the EGF-R, also identified to be responsible for EGF binding. Thus, each of the two theoretically predicted sites is composed of half sites whose functional importance is experimentally verified. This correspondence supports the principal suitability of PSS-1 and suggests that EGF binds to EGF-R at least in part by means of HC contacts besides using, most probably, also "classical" (i.e. non-HC-type) contacts (e.g. charge interactions or hydrophobic bonds).

New biosynthetic anthracyclines related to barminomycins incorporating barbiturates in their moiety

Three new anthracyclines, FCE 21424 (2), FCE 24366 (3) and FCE 24367 (4), were isolated from culture broths of Streptomyces peucetius and its mutant strains after addition of sodium barbiturates during the fermentation. Structural assignment, achieved through spectroscopic and degradative studies, that the new anthracyclines had a common barminomycin-like structure incorporating different barbiturate moieties. The new anthracyclines were found to display outstanding cytotoxicity and remarkable potency "in vivo" against P388 ascitic leukemia.

A single amino acid interchange yields reciprocal CTL specificities for HIV-1 gp160

For the IIIB isolate of human immunodeficiency virus type-1 (HIV-1), the immunodominant determinant of the envelope protein gp160 for cytotoxic T lymphocytes (CTLs) of H-2d mice is in a region of high sequence variability among HIV-1 isolates. The general requirements for CTL recognition of peptide antigens and the relation of recognition requirements to the natural variation in sequence of the HIV were investigated. For this purpose, a CTL line specific for the homologous segment of the envelope from the MN isolate of HIV-1 and restricted by the same class I major histocompatibility (MHC) molecule (Dd) as the IIIB-specific CTLs was raised from mice immunized with MN-env-recombinant vaccinia virus. The IIIB-specific and MN-specific CTLs were completely non-cross-reactive. Reciprocal exchange of a single amino acid between the two peptide sequences, which differed in 6 of 15 residues, led to a complete reversal of the specificity of the peptides in sensitizing targets, such that the IIIB-specific CTLs lysed targets exposed to the singly substituted MN peptide and vice versa. These data indicate the importance of single residues in defining peptide epitopic specificity and have implications for both the effect of immune pressure on selection of viral mutants and the design of effective vaccines.

Group-specific, major histocompatibility complex class I-restricted cytotoxic responses to human immunodeficiency virus 1 (HIV-1) envelope proteins by cloned peripheral blood T cells from an HIV-1-infected individual

Freshly separated unfractionated peripheral blood mononuclear cells (PBMC) and cloned cell lines from a healthy human immunodeficiency virus 1 (HIV-1)-seropositive individual were examined for cytotoxic responses to HIV proteins expressed by recombinant vaccinia viruses. It was found that freshly isolated PBMC recognize variant envelope proteins of HIV-1 but not a more distantly related envelope protein derived from the simian immunodeficiency virus (SIVmac). Although the effector cells were predominantly CD8+, both MHC-matched and -unmatched target cells were lysed. Cytotoxic T lymphocyte (CTL) clones were found to lyse cells expressing HIV-1 envelope or reverse transcriptase. In contrast to the cytotoxic response detected with PBMC, the cloned CTLs were major histocompatibility complex (MHC) class I restricted. Our finding that a cloned CTL line lysed cells expressing highly divergent HIV envelopes strongly suggested that a conserved epitope was recognized. Identification of these shared epitopes may assist in designing a vaccine for HIV-1 that could stimulate MHC-restricted cytotoxic responses.