Immunosuppressive therapy and oral anticoagulation in kidney transplant recipients: Direct oral anticoagulants versus vitamin-k antagonists

BACKGROUND

direct oral anticoagulants (DOACs) are an alternative to conventional antagonist of vitamin-K (AVK). However, immune suppressive drugs (ISDs) may interfere with DOACs pharmacokinetic.

AIM OF THIS STUDY

evaluate safety and efficacy profile of DOACs compared to AVK in kidney transplant recipients (KTRs) treated with ISDs.

METHODS

a multi-center study from 4 Italian University hospitals enrolling consecutive KTRs on DOACs or AVK was carried out. Sixty-six patients on DOACs were compared with fifty patients on AVK with similar clinical features. Serial evaluation of renal function and serum levels of ISDs during 18 months follow-up (FU) was performed.

RESULTS

Mean age of DOACs patients was 67±9 and mean eGFR was 58,3± 30,4mL/min/1.73m2. ISDs included tacrolimus (n=47, 71%), cyclosporin (n=13, 20%), everolimus (n=10, 7%) and sirolimus (n=4, 6%). After 14 days of DOACs therapy initiation there was a slight increase of serum levels of tacrolimus (+0.19±0.67 p=0.80) and cyclosporine (+0.12±0.25 p=0.94) not statistically significant. Levels of Tacrolimus and cyclosporin were stable at serial evaluation during 18-months follow-up. There were no thromboembolic events among patients treated with DOACs or AVK and no differences in term of major bleeding (6% vs 4% p=0.69), at long-term follow-up. There was no difference in term of eGFR decline from start therapy to 18 months FU between DOACs vs AVK therapy (-3.9±1 vs -3.8±2 p=0.82).

CONCLUSION

DOACs have similar safety and efficacy than AVK among KTRs treated with ISDs. However, careful evaluation of potential drug interaction and ISDs serum levels is needed.

Kinetics of humoral immune response and severity of infection after three doses of SARS-CoV-2 mRNA vaccine in a large cohort of kidney transplant recipients

BACKGROUND

COVID-19 in kidney transplant recipients is associated with high morbidity and mortality. In this study we aimed to evaluate: (i) the seroconversion rate after BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 vaccine, (ii) factors associated with humoral response, (iii) clinical outcome of COVID-19 in kidney transplanted patients.

METHODS

We enrolled a cohort of 743 kidney transplant recipients followed up from March 2020 until April 2022. A subset of 336 patients, who received three-doses of SARS-CoV-2 vaccine, was analyzed in terms of kinetics of humoral immune response and compared to a control group of 94 healthcare workers. Antibody response was tested before vaccination (T₀), 15 and 90 days after the second dose (T₁ and T₂), on the day of the third dose (T₃) and one month after the third dose (T₄).

RESULTS

We observed that 66 out of 743 subjects had COVID-19 infection pre-vaccination: 65.2% had severe symptoms, 27.3% were hospitalized (9 deaths), none were asymptomatic. After three doses, 51 patients had COVID-19 infection, 60.8% were asymptomatic, 27.5% reported mild symptoms, 3.9% showed severe symptoms, 7.8% were hospitalized (2 deaths). In the subset of 336 vaccinated patients, an antibody level > 0.8 U/ml was detected at T₁, that increased at T₂ and T_3, peaking at T₄. Independent factors associated with a negative antibody titer at T₄ were decreasing estimated glomerular filtration rate, time from transplantation, and antimetabolites (all p < 0.001) and age (p = 0.007).

CONCLUSIONS

The kinetics of humoral response after three doses of vaccine in kidney transplant patients is characterized by a late but effective immune response against SARS-CoV-2, reducing morbidity and mortality.

MO186: Third COVID-19 Vaccine Dose Maximizes Antibody Titer in Kidney Transplant Recipients

BACKGROUND AND AIMS

COVID-19 infection in solid organ transplant recipients (SOT) is associated with increased morbidity and mortality due to comorbidities and immunosuppression state (Chaudhry ZS et al, 2020). Although vaccines represent the greatest hope to control COVID-19 pandemic, several studies showed the low immunogenicity of a two-dose mRNA COVID-19 vaccine regimen in SOT as compared with general population (Boyarsky BJ et al, 2021). Based on this evidence, on September 2021, the Italian Medicine Agency (AIFA) authorized a third vaccine administration as additional primary dose to immunocompromised patients.

The aim of this study is to evaluate the seroconversion rate after the third dose of BNT162b2 (Pfizer-BioNTech) SARS-CoV-2 mRNA vaccine in kidney transplant recipients (KTRs) and to investigate the baseline factors associated with the absence of the antibody response.

METHOD

we performed a prospective and observational study on a monocentric cohort of 329 consecutive Caucasian KTRs given three doses of the BNT162b2 COVID-19 vaccine. Key exclusion criteria were a previous history of COVID-19 infection and transplantation or having underwent chemotherapy treatment within the last year. Antibody response against the spike protein was tested on blood sample collected before the administration of vaccine (T₀), at 15 and 90 days after the second dose (T₂ and T_3, respectively) and one month after the third dose (T₅). The level of antibodies was assessed using the Roche Elecsys anti–SARS-CoV-2 S enzyme immunoassay (positive cut-off ≥ 0.8 U/mL). A total of 22 patients were excluded from the analysis because categorized as SARS-CoV-2-pre-immunized according to the antibodies’ baseline status (T₀) above the positivity cut-off.

The Local Ethics Committees approved the study protocol and written informed consent was obtained before enrolment.

RESULTS

The study population of 307 KTRs was 57.10 ± 13.10 years, with a predominance of male sex (64.2%). Median time from transplantation to vaccine was 10 [IQR 5–17] years. Blood analysis at baseline revealed mean eGFR assessed by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to be 56.95 ± 23.04 mL/min/1.73 m².

The standard immunosuppressive regimen consisted of glucocorticoids in all patients, calcineurin inhibitors (88.6% of patients), antimetabolites (73.3% of patients) and mTOR inhibitors (in 15.6% of patients). The first two doses were administered 21 days apart, and the third dose was administrated 172 ± 4 days after the second dose.

In our cohort, 43.3% patients (133/307) responded to the vaccine at T₂. The proportion of responders increased to 68.4% (186/272) at T₃ (median antibody level: 5.2 [0.40–74.07]). One month after the third dose, a positive antibody titer was detected in 251 of 307 patients (81.8%) (median antibody titre: 1137.50 [9.32–4189.75]). The response curve starting at T₂ and increasing at T₃ makes apparent that there is a distinctive kinetic of humoral response in immunocompromised patients compared to immunocompetent individuals (Walsh EE et al., 2020). A multivariate analysis showed that the negative response to the third primary dose was associated with antimetabolite immunosuppressants (P = .001), lower estimated glomerular filtration rate (P < .001) and female sex (P = .04) (Figure 1). No serious adverse events were reported. Neither denovo DSAs nor change in proteinuria were reported after vaccination.

The limitation of this study is the absence of assays for cellular immune response.

CONCLUSION

Although the exact threshold of antibody titer for protection against SARS-CoV-2 infection remains unclear, the ability of the additional mRNA COVID-19 vaccine dose to increase both immune response (Figure 2A) and the prevalence of seroconversion rate (Figure 2B) associated with the acceptable safety profile supports its use after an initial 2-dose mRNA COVID-19 primary vaccine series in immunocompromised patients.

Nanowire based bioprobes for electrical monitoring of electrogenic cells

The continuous miniaturization of electronic components and the emergence of nano-biotechnology has opened new perspectives to monitor electrical activities at the single cell level. Here, we describe the creation of very high surface-to-volume ratio passive devices (vertical nanowire probes) using large-scale fabrication process, allowing to follow the electrical activity of mammalian neurons. Based on conventional silicon processing, the silicon nanowires were silicided in platinum in order to improve their electrochemical performances and to guarantee their biocompatibility. Very high signal to noise ratio was achieved (up to 2000) when measuring spontaneous action potentials. Moreover, this bio-platform was used to record the impact of various bio-chemical and electrical stimulations on neuronal activity. To conclude, this study proposes a thorough comparison of the characteristics and performances of these new nanowire-based nanoprobes with the main alternative systems published up to now.

Quantification of the overall measurement uncertainty associated with the passive moss biomonitoring technique: Sample collection and processing

In this study we examined 6080 data gathered by our research group during more than 20 years of research on the moss biomonitoring technique, in order to quantify the variability generated by different aspects of the protocol and to calculate the overall measurement uncertainty associated with the technique. The median variance of the concentrations of different pollutants measured in moss tissues attributed to the different methodological aspects was high, reaching values of 2851 (ng·g^-1)² for Cd (sample treatment), 35.1 (μg·g^-1)² for Cu (sample treatment), 861.7 (ng·g^-1)² and for Hg (material selection). These variances correspond to standard deviations that constitute 67, 126 and 59% the regional background levels of these elements in the study region. The overall measurement uncertainty associated with the worst experimental protocol (5 subsamples, refrigerated, washed, 5 × 5 m size of the sampling area and once a year sampling) was between 2 and 6 times higher than that associated with the optimal protocol (30 subsamples, dried, unwashed, 20 × 20 m size of the sampling area and once a week sampling), and between 1.5 and 7 times higher than that associated with the standardized protocol (30 subsamples and once a year sampling). The overall measurement uncertainty associated with the standardized protocol could generate variations of between 14 and 47% in the regional background levels of Cd, Cu, Hg, Pb and Zn in the study area and much higher levels of variation in polluted sampling sites. We demonstrated that although the overall measurement uncertainty of the technique is still high, it can be reduced by using already well defined aspects of the protocol. Further standardization of the protocol together with application of the information on the overall measurement uncertainty would improve the reliability and comparability of the results of different biomonitoring studies, thus extending use of the technique beyond the context of scientific research.

Poor achievement of guidelines-recommended targets in type 2 diabetes: findings from a contemporary prospective cohort study

AIMS

To prospectively evaluate diabetes management in the primary care setting and explore factors related to guideline-recommended triple target achievement [blood pressure (BP) ≤ 130/80 mmHg, A1C ≤ 7% and low-density lipoprotein (LDL)-cholesterol < 2.5 mmol/l].

METHODS

Baseline, 6 and 12 month data on clinical and laboratory parameters were measured in 3002 patients with type 2 diabetes enrolled as part of a prospective quality enhancement research initiative in Canada. A generalised estimating equation model was fitted to assess variables associated with triple target achievement.

RESULTS

At baseline, 54%, 53% and 64% of patients, respectively, had BP, A1C and LDL-cholesterol at target; all three goals were met by 19% of patients. The percentage of individuals achieving these targets significantly increased during the study [60%, 57%, 76% and 26%, respectively, at the final visit, p < 0.0001 except for A1C, p = 0.27]. A much smaller proportion of patients had adequate control during the entire study period [30%, 39%, 53% and 7%, respectively]. In multivariable analysis, women, patients younger than 65 years and patients of Afro-Canadian origin were less likely to achieve the triple target.

DISCUSSION

As part of a quality enhancement research initiative, we observed important improvements in the attainment of guidelines-recommended targets in patients with type 2 diabetes followed for a 12-month period in the primary care setting; however, many individuals still failed to achieve and especially maintain optimal goals for therapy, particularly the triple target. Results of the multivariable analysis reinforce the need to address barriers to improve diabetes care, particularly in more susceptible groups.

A haplotype of cyclooxygenase-2 gene is associated with idiopathic pulmonary fibrosis

BACKGROUND

Cyclooxygenase-2, a key regulatory enzyme in the synthesis of the antifibrotic agent prostaglandin E2, is downregulated in lung tissue from patients with idiopathic pulmonary fibrosis.

OBJECTIVE

To investigate the association between COX2.3050 (G --> C), COX2.8473 (C --> T) and COX2.926 (G --> C) single nucleotide polymorphisms (SNP) and the susceptibility to idiopathic pulmonary fibrosis and the progression of the disease.

DESIGN

Genetic polymorphisms were analyzed in 121 out of 225 available control subjects and in all of 174 patients with idiopathic pulmonary fibrosis by real time polymerase chain reaction. Logistic regression analysis of covariance and chi-squares test were used for statistical analysis.

RESULTS

While analysis of disease development did not find any significant association with single SNP genotype, a haplotype analysis revealed a strong association between the disease development and one haplotype [GC] at loci COX2.3050 and COX2.8473, and suggested a recessive genetic effect of this haplotype. Further analysis concluded that subjects having two copies of [GC] haplotype, or equivalently (GG/CC) genotype at the two SNPs, had an increased risk after adjusting for age and sex. Due to the interaction, this elevated risk increased slowly with age, and the estimated odds ratio (OR) decreased with age from OR = 1.4 at age 30 to OR = 1 at age 74 and OR = 0.96 at age SO. The OR was significantly greater than 1 up to age 66, and not significant for age older than 66. Therefore, the recessive effect of [GC] haplotype increased the risk of IPF of subjects younger than 66 years, but its effect diminished for seniors older than 66. One hundred and forty-nine patients with idiopathic pulmonary fibrosis were followed up for 33.7 +/- 2.1 months. Further analysis of disease progressions, defined by the changes in pulmonary function tests, did not reveal any association with either SNP genotypes or haplotypes.

CONCLUSIONS

The carriage of double homozygote (GG/CC) at the SNP loci of COX2.3050 and COX2.8473 polymorphisms may increase the susceptibility to idiopathic pulmonary fibrosis, by approximately 1.4 folds at age 30 and by a smaller fold greater than 1 up to age 66 years, but not the progression of the disease. These findings may help to improve our understanding of idiopathic pulmonary fibrosis pathogenesis and may lead to the development of new therapeutic strategies.

366 SEXING OF GOAT BLASTOCYSTS PRODUCED IN VITRO BY FISH USING CHROMOSOME X AND Y OVINE SPECIFIC PROBES

The aim of this study was to test a FISH approach using ovine-painted probes specific for the chromosomes X and Y, on goat interphase and metaphase nuclei of blastocyst cells. Oocytes of prepubertal goats were recovered at a slaughterhouse and selected by morphological criteria. Oocytes were matured in TCM-199 supplemented with hormones, serum and cysteine at 38.5°C for 27 h. IVM-oocytes were fertilized in vitro and the presumptive zygotes were cultured for 10 days in SOF with 10% FCS at 38.5°C, 5% CO2 and 5% O2. The blastocyst nuclei were spread using a modified Tarkowski method (1966). Briefly, individual embryos were immersed into hypotonic solution for 5 min, followed by fixative solution of methanol/acetic acid (Carnoy’s solution) until the embryos acquired a transparent appearance. Next, the embryos were transferred to a Superfrost plus Slide (Menzel Gläser, Braunschweig, Germany) in a small droplet mixture of distilled water and Carnoy The zona pellucida and the blastomere cytoplasm dissolved gradually and Carnoy solution was added dropwise to the slide before the nuclei dried out. The morphology and total number of nuclei in each embryo were analyzed under phase contrast microscope and stored at -18°C. Embryos with appropriate fixation were then subjected to hybridization with ovine-painted probes specific to chromosomes X (Fluorocrom green-FITC) and Y (Fluorocrom orange-TAMRA) (Chrombios-Molecular Cytogenetics GmbH, Raubling, Germany) according to the manufacturers protocol and adjusted for the caprine species. Briefly, slides were then incubated at 60°C for 1 h. The chromosomal DNA was then denatured by immersing slides in 70% formamide/30% 2 × SSC at 70°C for 1.5 min, and immediately dehydrated in an ethanol series (70%, 90%, and 100%), 4 min duration per solution and air dried. In parallel, X- and Y-probes were added to the hybridization solution (50% deionized formamide, 10% dextran sulfate, 2 × SSC) and denatured at 75°C for 10 min. Aliquots (0.5 to 1.5 μL) of this solution were placed on each slide and sealed with a coverslip and glue prior to incubation at 37°C (Hybrite; Vysis Inc, Dowers Grove, IL, USA). After 22 to 24 h the coverslip was removed and the slides were washed three times. The first and third washes were performed with 2 × SSC at room temperature while the second wash was in a 0.4 × SSC/0.1% Tween at 73°C for 3 min. Nuclear DNA was counterstained with diamino-phenyl-indole solution (DAPI) and examined with a fluorescence microscope (Olympus BX61, Olympus America Inc., Melville, NY, USA) equipped with appropriate filters. From a total of 69 blastocysts, 11 355 blastomeres were analyzed and 7,825 were correctly hybridized (68.9%). The results of the embryo sexing were: 24 embryos XX, 11 XY, 22 polyploid embryos (of which 13 presented more than 80% of cells XX), 3 haploid embryos (X0), 2 tetraploid embryos, and 5 no result. In summary, goat blastocysts were successfully sexed using FISH with painted ovine X- and Y-specific probes. Grant sponsor Spanish Ministery of Science and Innovation.Code: AGL2007-60227-CO2-01.

Lymphangioleiomyomatosis: a study of 72 patients from the Spanish registry

BACKGROUND

Pulmonary lymphangioleiomyomatosis (LAM) is a rare lung disease that almost exclusively affects young women of childbearing age. The true incidence and prevalence of LAM are unknown. This study was conducted to evaluate the characteristics of lymphangioleiomyomatosis in Spain.

METHODS

Over a 2-year period, a questionnaire designed for this study was collected. This questionnaire included sociodemograhic, clinical, radiological and functional data. Information about the study and this questionnaire were both sent by e-mail to all the participants of the interstitial disease registry of 2004.

RESULTS

Seventy-two patients, all of whom were women, were included in the registry, with a mean age of 44.56 +/- 11.1 yr. Sixty-three patients (87.5%) presented the sporadic LAM and 9 (12.5%) presented LAM associated with tuberous sclerosis (LAM-TS). LAM diagnosis was confirmed with an open lung biopsy in 57 patients (79.2%) and was performed with thoracic HRCT compatible with LAM diagnosis in the other 15 cases. The most frequent symptom was dyspnoea (90%) followed by cough (44.4%). Almost 40% of patients presented renal angiomyolipomas in the study and the most frequent spirometric pattern was obstructive in more than half of the patients. Most patients with LAM-TS (88.8%) had renal angiomyolipomas compared with 31.7% in the sporadic LAM group.

CONCLUSION

The characteristics of the Spanish population affected with LAM are similar to those of other countries. Most patients were symptomatic, had a history of previous pneumothorax and presented abnormal radiological findings and pulmonary function tests.

Angiotensinogen gene G-6A polymorphism influences idiopathic pulmonary fibrosis disease progression

Angiotensin II is a growth factor that plays a key role in the physiopathology of idiopathic pulmonary fibrosis (IPF). A nucleotide substitution of an adenine instead of a guanine (G-6A) in the proximal promoter region of angiotensinogen (AGT), the precursor of angiotensin II, has been associated with an increased gene transcription rate. In order to investigate whether the G-6A polymorphism of the AGT gene is associated with IPF development, severity and progression, the present study utilised a case-control study design and genotyped G-6A in 219 patients with IPF and 224 control subjects. The distribution of G-6A genotypes and alleles did not significantly differ between cases and controls. The G-6A polymorphism of the AGT gene was not associated with disease severity at diagnosis. The presence of the A allele was strongly associated with increased alveolar arterial oxygen tension difference during follow-up, after controlling for the confounding factors. Higher alveolar arterial oxygen tension changes over time were observed in patients with the AA genotype (0.37+/-0.7 mmHg (0.049+/-0.093 kPa) per month) compared to GA genotype (0.12+/-1 mmHg (0.016+/-0.133 kPa) per month) and GG genotype (0.2+/-0.6 mmHg (0.027+/-0.080 kPa) per month). G-6A polymorphism of the angiotensinogen gene is associated with idiopathic pulmonary fibrosis progression but not with disease predisposition. This polymorphism could have a predictive significance in idiopathic pulmonary fibrosis patients.

Preliminary Results of Treatment With Pegylated Interferon Alpha 2A for Chronic Hepatitis C Virus in Kidney Transplant Candidates on Hemodialysis

INTRODUCTION

At present, there is little published information on the outcome of treatment with pegylated interferon (Peg-IF alpha 2a) in hepatitis C virus (HCV)-infected hemodialysis patients awaiting renal transplantation. The objective of this study was to assess the efficacy and tolerance of Peg-IF alpha 2a in this population.

PATIENTS AND METHODS

Twelve noncirrhotic HCV-infected patients (10 men, 50 +/- 8 years of age, genotype 1b 84%), were prescribed Peg-IF alpha 2a, at 135 microg/wk for 48 weeks. Liver biopsy was performed in 11 of 12 cases.

RESULTS

Six patients completed 48 weeks of treatment, with one end of treatment response (ETR), two sustained viral responses (SVRs), and three HCV relapses. Treatment was shorter in the six remaining patients: two cases 24 weeks (one due to medical reasons with relapse, one due to nonresponse), one patient chose to discontinue at 14 weeks (with relapse), one patient died of stroke at 10 weeks, and in two additional patients interferon was withdrawn at 18 weeks because of severe anemia (SVR) and at 26 weeks due to prolonged fever (relapse). Other secondary treatment-related events included anemia (requiring transfusion in two patients and major erythropoietin administration in six), and fever in four patients.

CONCLUSIONS

Peg-IF had limited efficacy in this group, with ETR in 83%, SVR in only 25%, and recurrence in 50%. Tolerance was moderate, with 4/12 (33%) discontinuing treatment due to adverse events, personal decision, or death. Large randomized controlled studies are needed to determine the role of Peg-IF treatment in this population.

Secondary serological response of patients with chronic hepatosplenic suppurative brucellosis

Chronic hepatosplenic suppurative brucellosis (CHSB) is a local reactivation of a previous brucellosis, coursing with an immunoglobulin G (IgG) and IgA secondary immunological response. The observation of two cases of CHSB with an apparent IgM response gave rise to a detailed serological study of three of our patients. We studied the first sample from all three patients and successive samples from two of them. In cases 1 and 2, we found samples with positive IgM lateral flow and IgM enzyme-linked immunosorbent assay results concomitantly with rheumatoid factor (RF); after absorption with anti-RF serum, these results were rendered negative. In patients 2 and 3 the diagnosis of brucellosis was delayed, because none of the test results were initially very significant. However, a clear seroconversion of IgG antibodies was observed in subsequent months; titers of the Brucellacapt and Coombs tests increased in similar ways, although Brucellacapt decreased more rapidly than Coombs, which persisted at high titers for years. In patient 3 a relapse was observed in the fourth year of follow-up, detected by Coombs and also by IgG lateral flow and counterimmunoelectrophoresis (CIEP), although not by the rose bengal, agglutination, or Brucellacapt tests. Serological changes in CHSB may sometimes be mild and are detected mainly by the Coombs test. Brucellacapt does not offer additional information, although IgG lateral flow and CIEP may be of some use. Careful surveillance of titer changes in the Coombs test is the best marker of infection activity. As the disease progresses, an intense IgG response may develop and RF sometimes appears, simulating an IgM response.

Polyradiculitis and Wegener's Granulomatosis

Wegener's granulomatosis is a systemic vasculitis of unknown etiology, primarily affecting the upper and lower respiratory tract and the kidneys, although there is a form restricted to the lungs. Wegener's granulomatosis occurs infrequently, with an estimated annual incidence of 8.5 cases per million. The principal symptoms at onset usually involve the upper and lower airway. The central nervous system is involved in approximately 22% of cases, but neurological signs occur infrequently among the initial clinical manifestations. Proteinase 3-specific antineutrophil cytoplasmic antibodies are useful serological markers for establishing a diagnosis, which should, however, be confirmed by a tissue biopsy of the affected organ.

Etiology, reasons for hospitalization, risk classes, and outcomes of community-acquired pneumonia in patients hospitalized on the basis of conventional admission criteria

We performed an observational analysis of prospectively collected data on 533 nonseverely immunosuppressed adult patients who were hospitalized for community-acquired pneumonia on the basis of conventional admission criteria. For this population, we correlated etiology, reasons for admission, and outcomes using the Pneumonia Severity Index (PSI), to identify major discrepancies between the PSI risk class and the conventional criteria for deciding the site of care. PSI classes and corresponding mortality rates were as follows: class I, 51 patients (0%); class II, 62 (2%); class III, 117 (3%); class IV, 198 (10%); and class V, 105 (29%). We identified significant discrepancies between both methods. Overall, 230 patients (40%) who were hospitalized according to conventional criteria were assigned to low-risk classes. Of these 230 patients, 137 (60%) needed supplementary oxygen or had pleural complications; for the remaining patients, there were no irrefutable reasons for admission. This latter group deserves prospective evaluation in randomized studies that compare ambulatory and in-hospital management.

A combination of interleukin-2 and 60 nm cationic supramolecular biovectors for the treatment of established tumours by subcutaneous or intranasal administration

The Supramolecular Biovector (SMBV) KY is a drug delivery nanocarrier which consists of a discretely sized, ionically charged, cross-linked polysaccharide core surrounded by a lipid membrane. We used the non-immunogenic spontaneous mammary adenocarcinoma TS/A tumour to test the efficacy on tumour growth of low (10(4) IU) or ultra-low (10(3) IU) doses of interleukin-2 (IL-2) adsorbed to these 60 nm cationic synthetic particles. In comparison with the progressive growth of TS/A cells in syngeneic mice, KY/IL-2 particles coinjected with TS/A cells or administered at a distance from the tumour, inhibited tumour growth while free IL-2, even at 10-100 times the dose used in the KY/IL-2 formulations, had no effect. Studies performed on implanted tumours (treatment at day 6 (D6)) showed that KY/IL-2 administered subcutaneously (s.c.) at five sites distant from the tumour (10(3) IL-2 IU per site) induced rejection of the implanted tumours. Six out of 10 mice were cured while the other four had residual tumours only. In the same experiment, free IL-2 induced only tumoral growth reduction. Protection induced by KY/IL-2 administered s.c. at five sites involved recruitment of a CD8(+) T cell response since nu/nu mice and CD8-depleted mice did not reject the tumours. Mice cured were protected significantly to completely against a rechallenge with TS/A tumour cells, and a systemic tumour-specific CTL activity was induced. Finally, we showed that repeated intranasal (i.n.) administration of KY/IL-2 (low-dose) also led to complete regression of pre-established tumours and partial protection from tumour rechallenge. We therefore suggest that, in contrast to free IL-2, a KY/IL-2 formulation could be used as a systemic immunostimulant leading to the eradication of non-immunogenic, established tumours.

Current understanding and management of chronic hepatosplenic suppurative brucellosis

To outline the characteristics and define appropriate management of chronic hepatosplenic suppurative brucellosis (CHSB), 905 patients with brucellosis were analyzed. Sixteen episodes of CHSB (14 in the liver and 2 in the spleen) were found in 15 patients. Six patients had had previous remote brucellosis. Twelve patients presented with systemic symptoms, and 12 with local symptoms. Cultures of blood samples yielded negative results in all cases except 1, and the results of cultures of pus specimens were positive for Brucella melitensis in only 2 cases. All patients showed calcium deposits surrounded by a hypodense area on computed tomography. Patients often had low titers of agglutinating antibody. In patients who were receiving conservative management, early response was successful in 50% and late response was successful in 33.3%. In the patients who underwent surgery and concomitant antibiotic therapy, early and late response was successful in 100%. Thus, CHSB mainly represents a local reactivation of previous brucellosis. Its diagnosis may be difficult to establish and surgery may be required to cure many patients.

tRNA genes were found in Piscirickettsia salmonis 16S-23S rDNA spacer region (ITS)

Piscirickettsia salmonis is the etiological agent of Salmonid Rickettsial Septicemia, a disease affecting salmon aquaculture industry. We analyzed the 16S-23S rDNA spacer region (internal transcribed spacer, ITS) of Chilean P. salmonis isolates LF-89 and EM-90. Two main ITS amplification products were obtained by PCR using L1 and G1 primers, differing from that described where only one ITS region was found. By Southern blot, it was established that these two amplification products contained sequences related to P. salmonis ITS. Sequence analysis confirmed that P. salmonis had two ITS regions: ITS A and ITS B. In both isolates, the smaller (ITS B) corresponded to ITS sequences previously described for each one, and the larger (ITS A) were almost the same as their respective ITS B sequences interrupted by an insert which contained two tRNAs genes: tRNA-Ile and tRNA-Ala.

Efficacy of interferon for chronic hepatitis C virus-related hepatitis in kidney transplant candidates on hemodialysis: results after transplantation

OBJECTIVES

Interferon-alpha (IFN) may have undesirable effects on a functioning graft. The aim of this study was to evaluate IFN treatment in kidney transplant candidates during the hemodialysis period as well as the results after transplantation.

METHODS

A total of 29 noncirrhotic hemodialysis patients with chronic hepatitis C virus (HCV) infection (based on long-term rise in ALT, HCV serology, HCV RNA by polymerase chain reaction methods, and histological evidence) were included. Tolerability to IFN treatment, pre- and posttransplantation therapeutic results, and long-term outcome were recorded. IFN regimen consisted of 3 million units (MU) times per week after hemodialysis sessions for 6 months, followed by 1.5 MU after each hemodialysis session for an additional 6 months. All patients gave informed consent for participation.

RESULTS

IFN therapy was fairly well tolerated. Adverse effects due to IFN toxicity, renal disease, or causes related to the immunological properties of IFN were observed in 24% of patients. At the end of treatment, ALT had normalized in 23/28 patients (82.1%), and HCV RNA had cleared in 23/28 patients (82.1%). During follow-up, HCV RNA was persistently negative in 18 patients (64%, including transplant recipients). A total of 14 patients (nine HCV RNA-negative) received a kidney transplant. Mean follow-up after the procedure was 41 +/- 28 months. In all, 12 patients had a functioning graft, one had acute vascular rejection, and one died of carcinoma. All transplanted patients maintained normal ALT levels, and eight remained HCV RNA-negative.

CONCLUSIONS

Treatment results in our study population were better than those observed in the general population. The long-term response achieved, which was maintained after transplantation, supports the use of IFN for HCV hepatitis in kidney transplant candidates under hemodialysis.

[Respiratory syncytial virus infection in adult patients hospitalized with community-acquired pneumonia]

OBJECTIVE

To determine the incidence and distribution of infection caused by respiratory syncytial virus (RSV) in hospitalized adults with community-acquired pneumonia.

PATIENTS AND METHODS

Patients were immunocompetent adults hospitalized with community-acquired pneumonia, who were prospectively studied in our hospital. As a part of the diagnostic protocol, we performed RSV serology with paired acute and convalescent phase sera of patients admitted between February 1995 and May 1997. Clinical and epidemiological characteristics of patients with and without acute infection were compared.

RESULTS

Paired RSV serology was performed in 250 patients hospitalized with community-acquired pneumonia. 97% of them had presence of IgG antibodies but only 17 patients (6.8%) had serologic evidence of acute infection; of these, seroconversion was observed in eight and positive IgM in nine. Fourteen cases with acute infection (82%) occurred between November and May. Three patients had pneumococcal pneumonia, 2 Legionella pneumophila and 12 pneumonia of unknown etiology. There were no clinical differences between patients with and without RSV acute infection but those with acute infection had more frequently bilateral involvement in chest radiography and a greater proportion of pneumonias of unknown etiology.

CONCLUSIONS

RSV is a cause of acute infection among adults hospitalized with community-acquired pneumonia, mainly between November and May. Further studies to assess the role of RSV as a causative agent of pneumonia in this population are needed.

Evaluation of effect of charge and lipid coating on ability of 60-nm nanoparticles to cross an in vitro model of the blood-brain barrier

A cell culture model of the blood-brain barrier (BBB) consisting of a coculture of bovine brain capillary endothelial cells and rat astrocytes has been used to examine the ability of 60-nm nanoparticles with different physicochemical characteristics to cross the BBB. Neutral, anionic, and cationic nanoparticles were made from crosslinked malto-dextrins derivatized or not (neutral) with phosphates (anionic), quaternary ammoniums (cationic) ligands. Then, these particles were coated or not with a lipid bilayer made of dipalmitoyl phosphatidyl choline and cholesterol. Lipid coating of ionically charged nanoparticles was able to increase BBB crossing 3- or 4-fold compared with uncoated particles, whereas coating of neutral particles did not significantly alter their permeation characteristics across the endothelial cell monolayer. Lipid-coated nanoparticles were nontoxic toward BBB integrity, and crossed the BBB by transcytosis without any degradation. Furthermore, a 27-fold increase in albumin transport was observed when albumin had previously been loaded in the cationic lipid-coated nanoparticles. The influence of red blood cells was studied; a marked inhibition of the transport was observed, probably due to strong interaction between nanoparticles and red blood cells.

Usefulness of PCR and antigen latex agglutination test with samples obtained by transthoracic needle aspiration for diagnosis of pneumococcal pneumonia

In a large number of cases, the etiology of community-acquired pneumonia (CAP) is not established. Some cases are probably caused by Streptococcus pneumoniae. Transthoracic needle aspiration (TNA) culture has a limited sensitivity which might be improved by antigen detection or gene amplification techniques. We evaluated the capacity of a PCR assay and a latex agglutination test to detect S. pneumoniae in samples obtained by TNA from 95 patients with moderate-to-severe CAP. Latex agglutination and PCR had sensitivities of 52.2 and 91.3%, specificities of 88.7 and 83.3%, positive predictive values of 62.3 and 65.6%, and negative predictive values of 83.3 and 96.5%, respectively, when culture techniques were used as the "gold standard." When we considered expanded criteria for the diagnosis of pneumococcal pneumonia as a standard for our calculations, latex agglutination and PCR had sensitivities of 53.6 and 89.7%, specificities of 93.0 and 90.0%, positive predictive values of 78.9 and 81.3%, and negative predictive values of 80.3 and 94.7%, respectively. The additional diagnosis provided by the PCR assay compared to latex agglutination was 12.2% (95% confidence interval of the difference from 0.4 to 20. 1%). PCR was more sensitive than TNA culture, particularly in patients who had received prior antibiotic therapy (83.3 versus 33. 3%). Although PCR is a very sensitive and specific technique, it has not proved to be cost-effective in clinical practice. Conversely, latex agglutination is a fast and simple method whose results might have significant implications for initial antibiotic therapy.

Localization of putative receptors for tetanus toxin and botulinum neurotoxin type A in rat central nervous system

Clostridial neurotoxins (tetanus and botulinum toxins) are potent blockers of neurotransmitter release. These toxins act specifically on the nervous system by interacting with still non-identified protein receptors together with gangliosides. Whereas many biochemical data are available on their binding properties to neuronal membranes in vitro, there is poor morphological evidence of their binding to mammalian central nervous system. In the present study, the binding of tetanus and botulinum neurotoxin type A to rat brain sections is reported. Both toxins bound to nerve terminals with a broad distribution in brain. Tetanus toxin additionally bound to nerve fibres. The staining patterns were clearly shown to be due to the interaction of the heavy chains, which contain the binding moiety, with the tissue. In an attempt to investigate the nature of the acceptors present in the tissue, some sections were pre-incubated with periodic acid. This treatment resulted in the additional binding of botulinum neurotoxin type A to nerve fibres. Since the extended staining of nerve terminals was not modified by this pretreatment, it is suggested that protein receptors of clostridial neurotoxins are located at the nerve terminals, which may be common constituents of the synapses.

Helicobacter pylori, efficacy of the new triple therapy in six and twelve-day schedules

OBJECTIVE

Assessment of four eradicating patterns of 6 and 12 days duration with new triple therapies adapted to our environment.

PATIENTS

After an endoscopic diagnosis of Duodenal or Gastric Ulcer, and the confirmation of the presence of Helicobacter pylori using a rapid urease test in antral biopsies, 274 patients were treated with one of four eradicating therapies, verifying its efficacy with the C-13 urea breath test, at least one month after the end of the treatment and 10 days after withdrawal of proton pump inhibitors.

RESULTS

Maximum eradicating efficacy was achieved with Omeprazole (20 mg/12 hours), Clarithromycin (500 mg/12 hours) and Amoxycillin (1 g/12 hours), given for 12 days (96.6%), and Omeprazole (20 mg/12 hours), Tinidazole (500 mg/12 hours) and Clarithromycin (500 mg/12 hours), also given for 12 days (95.2%). The same drugs and doses, when given during six days, achieved percentages of 78.3% and 82.2% respectively. Results with Tinidazole suggest lack of resistance to this drug in the Community of Madrid.

Chloracne in the 1990s

BACKGROUND

Chloracne is a disease associated with toxicity of halogenated compounds used in some industrial processes. A patient affected by chloracne led us to study a total of nine cases from a single factory.

METHODS

We studied the clinical features of nine patients exposed chronically to chlorobenzenes. On all of them blood samples were drawn and biopsies of affected skin and liver were taken. Their work environment was visited and studied.

RESULTS

All nine patients were men and had polymorphic skin lesions, characterized mainly by comedones and cysts. They had chronic conjunctivitis and seven had cysts in the Meibomian glands. All of them had polyneuropathy and liver damage and seven had hypertriglyceridemia. Compounds known to cause chloracne were found in exceedingly high concentrations in the water used in the workplace.

CONCLUSIONS

Every patient exposed to halogenated compounds with the cutaneous manifestations of chloracne should be carefully investigated for systemic complications (such as ophthalmic, neuropathic, hepatic, and lipoprotein abnormalities).

Expression of synaptosomal-associated protein SNAP-25 in endocrine anterior pituitary cells

A growing body of evidence indicates that the fundamental molecular mechanism of exocytosis in the secretory pathway may be structurally similar in all eukaryotic cells. The synaptosomal-associated protein of 25 kDa (SNAP-25) is a plasma membrane protein involved in regulated exocytosis in neurons. In order to compare exocytotic components in neurons and endocrine cells, we have analyzed the expression of SNAP-25 in the rat anterior pituitary. Western blotting analysis documented the presence of SNAP-25 in anterior pituitary homogenates and cultured anterior pituitary cells. In addition to SNAP-25, other neuronal proteins involved in exocytosis (syntaxin, VAMP/synaptobrevin and Rab3A) were also detected in the anterior pituitary. The specific expression of SNAP-25 mRNA in anterior pituitary cells was also corroborated by Northern analysis. SNAP-25 immunoreactivity was located at the plasma membrane of endocrine anterior pituitary cells. Characteristically, patches of fine punctate deposits exhibited intense SNAP-25 immunoreactivity. Double-labeling immunocytochemistry revealed that SNAP-25 was mainly associated with gonadotroph cell populations. Furthermore, we demonstrate that in the anterior pituitary, SNAP-25 is selectively cleaved by clostridial neurotoxins. In conclusion, our results establish the presence of SNAP-25 in secretory anterior pituitary cells and suggest a potential role of this protein in the secretion of adenohypophysial hormone.

Central hypoventilation syndrome associated with ganglioneuroblastoma

In this paper the authors describe a case of central hyperventilation syndrome associated with a neural crest tumor. The girl had several apneic spells at the age of three years. She had a tracheostomy and mechanically assisted ventilation while asleep. Routine hematologic studies and chest x-ray were within normal limits. Computerized tomography scan and magnetic resonance imaging revealed a left paraspinal mass suggestive of a neural crest tumor. This mass was excised and histopathologic findings of this tumor revealed a ganglioneuroblastoma.

Botulinum toxin type A inhibits Ca(2+)-dependent transport of acetylcholine in reconstituted giant liposomes made from presynaptic membranes from cholinergic nerve terminals

Giant liposomes were made from a mixture of asolectin phospholipid vesicles and presynaptic plasma membranes isolated from Torpedo cholinergic nerve endings. Acetylcholine filled giant liposomes were able to release neurotransmitter upon stimulation by the Ca2+ ionophore A23187 and Ca2+. Botulinum neurotoxin type A inhibited this Ca(2+)-dependent acetylcholine transport. Additionally, Botulinum toxin type A decreased membrane fluidity of liposomes. These results suggest that Botulinum toxin can interact directly with components of the presynaptic plasma membrane and inhibit acetylcholine translocation. Furthermore, since the reconstituted liposomes do not have synaptic vesicle components, the observed effects may account for the action of Botulinum toxin on the non-quantal release of acetylcholine from motor nerve terminals.

Intermittent trimethoprim-sulfamethoxazole compared with dapsone-pyrimethamine for the simultaneous primary prophylaxis of Pneumocystis pneumonia and toxoplasmosis in patients infected with HIV

OBJECTIVE

To evaluate the efficacy and safety of two oral, intermittent drug regimens for the simultaneous primary prophylaxis of Pneumocystis carinii pneumonia and toxoplasmosis in patients with HIV infection.

DESIGN

Nonblinded randomized study: Patients received either 1) trimethoprim-sulfamethoxazole (160 mg-800 mg orally twice a day on a thrice weekly regimen) or 2) 100 mg of dapsone plus 50 mg of pyrimethamine orally twice weekly.

SETTING

University teaching hospital in Barcelona.

PATIENTS

230 patients infected with HIV who had CD4 cell counts of less than 200 x 10(6)/L and who had not previously had P. carinii pneumonia or toxoplasmosis.

MEASUREMENTS

Clinical and biological evaluations; adverse reactions; and end points of P. carinii pneumonia, toxoplasmosis, and death.

RESULTS

After a median follow-up of 430 days, 6 (6.3%) of 96 evaluable patients receiving dapsone-pyrimethamine and 0 of 104 evaluable patients receiving trimethoprim-sulfamethoxazole developed P. carinii pneumonia (P < 0.0001). The cumulative rates of P. carinii pneumonia at 12 and 24 months were 0% and 0% for patients receiving trimethoprim-sulfamethoxazole and 4% and 11% for patients receiving dapsone-pyrimethamine (Mantel-Cox, P = 0.014). However, only one episode of P. carinii pneumonia developed while patients were taking these drugs. No differences were observed for toxoplasmosis (one episode in the trimethoprim-sulfamethoxazole arm and two in the dapsone-pyrimethamine arm), with cumulative rates at 12 and 24 months of 0% and 4% for the trimethoprim-sulfamethoxazole arm and 2% and 7% for the dapsone-pyrimethamine arm (P = 0.65). Similar mortality rates were observed during follow-up (P = 0.85). Nineteen patients (9.5%) discontinued therapy with the drugs because of adverse effects: Ten were in the trimethoprim-sulfamethoxazole arm and 9 were in the dapsone-pyrimethamine arm (P = 0.95).

CONCLUSIONS

Thrice-weekly trimethoprim-sulfamethoxazole is an effective and well-tolerated regimen for the simultaneous primary prophylaxis of P. carinii pneumonia and toxoplasmosis in patients infected with HIV. Twice-weekly dapsone-pyrimethamine appears to be a safe and effective alternative.

Cocket syndrome: thrombotic-septic disease post-appendicectomy complication

The incidence of complications following treatment of acute appendicitis in childhood is lower than 5%, while thromboembolic disease at that age is exceptional. The case of a 13-year-old male who was operated on in our pediatric surgery department for acute gangrenous appendicitis is presented. His condition improved until the sixth day after the operation when he suffered thrombosis in both the left iliac vein and the inferior cava. Ultrasonography, plethysmography and computer tomography (CT) studies were carried out and a diagnosis of venous thrombosis was made with an underlying congenital vascular malformation where the iliac vein was compressed by the overlying iliac artery; known as the Cocket syndrome. The etiology diagnosis and treatment of this rare disease in childhood is reviewed.

[Renal adenocarcinoma in children. Report of a case]

Description of the accidental finding of a renal adenocarcinoma in a 10-year old boy, after abdominal trauma and with a good evolutive behaviour. The clinical, diagnostic, therapeutical and survival aspects are analyzed, including a literature update of a renal neoformation which shows lower paediatric incidence than Wilm's Tumour or Neuroblastoma.

Insulin and lipogenesis in rat adipocytes. II. Effect of high levels of insulin and glucose on lipid synthesis in isolated rat adipocytes

Insulin resistant states are characterized by receptor and post-receptor defects in insulin action. When the insulin resistant state progresses, elevated levels of insulin are accompanied by increasing levels of glucose. In a previous paper we demonstrated that treatment of isolated adipocytes with high levels of insulin led to a decrease in insulin binding as well as a decrease in basal and insulin-stimulated lipid synthesis. The results of the present study establish that the addition of high concentrations of glucose in combination with a high level of insulin, does not modify the decrease in binding of insulin to its receptor. However, the decrease in lipid synthesis previously observed in the presence of high concentrations of insulin was completely overcome by the presence of high glucose.