Prior influenza vaccine is not a risk factor for bacterial coinfection in patients admitted to the ICU due to severe influenza

OBJECTIVE

To determine whether the prior usage of the flu vaccine is a risk factor for bacterial co-infection in patients with severe influenza.

DESIGN

This was a retrospective observational cohort study of subjects admitted to the ICU. A propensity score matching, and logistic regression adjusted for potential confounders were carried out to evaluate the association between prior influenza vaccination and bacterial co-infection.

SETTINGS

184 ICUs in Spain due to severe influenza.

PATIENTS

Patients included in the Spanish prospective flu registry.

INTERVENTIONS

Flu vaccine prior to the hospital admission.

RESULTS

A total of 4175 subjects were included in the study. 489 (11.7%) received the flu vaccine prior to develop influenza infection. Prior vaccinated patients were older 71 [61-78], and predominantly male 65.4%, with at least one comorbid condition 88.5%. Prior vaccination was not associated with bacterial co-infection in the logistic regression model (OR: 1.017; 95%CI 0.803-1.288; p=0.885). After matching, the average treatment effect of prior influenza vaccine on bacterial co-infection was not statistically significant when assessed by propensity score matching (p=0.87), nearest neighbor matching (p=0.59) and inverse probability weighting (p=0.99).

CONCLUSIONS

No association was identified between prior influenza vaccine and bacterial coinfection in patients admitted to the ICU due to severe influenza. Post influenza vaccination studies are necessary to continue evaluating the possible benefits.

Prior influenza vaccine is not a risk factor for bacterial coinfection in patients admitted to the ICU due to severe influenza

OBJECTIVE

To determine whether the prior usage of the flu vaccine is a risk factor for bacterial co-infection in patients with severe influenza.

DESIGN

This was a retrospective observational cohort study of subjects admitted to the ICU. A propensity score matching, and logistic regression adjusted for potential confounders were carried out to evaluate the association between prior influenza vaccination and bacterial co-infection.

SETTINGS

184 ICUs in Spain due to severe influenza.

PATIENTS

Patients included in the Spanish prospective flu registry.

INTERVENTIONS

Flu vaccine prior to the hospital admission.

RESULTS

A total of 4175 subjects were included in the study. 489 (11.7%) received the flu vaccine prior to develop influenza infection. Prior vaccinated patients were older 71 [61-78], and predominantly male 65.4%, with at least one comorbid condition 88.5%. Prior vaccination was not associated with bacterial co-infection in the logistic regression model (OR: 1.017; 95%CI 0.803-1.288; p=0.885). After matching, the average treatment effect of prior influenza vaccine on bacterial co-infection was not statistically significant when assessed by propensity score matching (p=0.87), nearest neighbor matching (p=0.59) and inverse probability weighting (p=0.99).

CONCLUSIONS

No association was identified between prior influenza vaccine and bacterial coinfection in patients admitted to the ICU due to severe influenza. Post influenza vaccination studies are necessary to continue evaluating the possible benefits.

Recommendations for the diagnosis and treatment of Clostridioides difficile infection: An official clinical practice guideline of the Spanish Society of Chemotherapy (SEQ), Spanish Society of Internal Medicine (SEMI) and the working group of Postoperative Infection of the Spanish Society of Anesthesia and Reanimation (SEDAR)

This document gathers the opinion of a multidisciplinary forum of experts on different aspects of the diagnosis and treatment of Clostridioides difficile infection (CDI) in Spain. It has been structured around a series of questions that the attendees considered relevant and in which a consensus opinion was reached. The main messages were as follows: CDI should be suspected in patients older than 2 years of age in the presence of diarrhea, paralytic ileus and unexplained leukocytosis, even in the absence of classical risk factors. With a few exceptions, a single stool sample is sufficient for diagnosis, which can be sent to the laboratory with or without transportation media for enteropathogenic bacteria. In the absence of diarrhoea, rectal swabs may be valid. The microbiology laboratory should include C. difficile among the pathogens routinely searched in patients with diarrhoea. Laboratory tests in different order and sequence schemes include GDH detection, presence of toxins, molecular tests and toxigenic culture. Immediate determination of sensitivity to drugs such as vancomycin, metronidazole or fidaxomycin is not required. The evolution of toxin persistence is not a suitable test for follow up. Laboratory diagnosis of CDI should be rapid and results reported and interpreted to clinicians immediately. In addition to the basic support of all diarrheic episodes, CDI treatment requires the suppression of antiperistaltic agents, proton pump inhibitors and antibiotics, where possible. Oral vancomycin and fidaxomycin are the antibacterials of choice in treatment, intravenous metronidazole being restricted for patients in whom the presence of the above drugs in the intestinal lumen cannot be assured. Fecal material transplantation is the treatment of choice for patients with multiple recurrences but uncertainties persist regarding its standardization and safety. Bezlotoxumab is a monoclonal antibody to C. difficile toxin B that should be administered to patients at high risk of recurrence. Surgery is becoming less and less necessary and prevention with vaccines is under research. Probiotics have so far not been shown to be therapeutically or preventively effective. The therapeutic strategy should be based, rather than on the number of episodes, on the severity of the episodes and on their potential to recur. Some data point to the efficacy of oral vancomycin prophylaxis in patients who reccur CDI when systemic antibiotics are required again.

Prediction of pathological response to neoadjuvant treatment in rectal cancer with a two-protein immunohistochemical score derived from stromal gene-profiling

Background

Preoperative chemoradiotherapy followed by surgical mesorectal resection is the standard of care for locally advanced rectal carcinomas. Yet, predicting that patients will respond to treatment remains an unmet clinical challenge.

Experimental design

Using laser-capture microdissection we isolated RNA from stroma and tumour glands from prospective pre-treatment samples (n = 15). Transcriptomic profiles were obtained hybridising PrimeView Affymetrix arrays. We modelled a carcinoma-associated fibroblast-specific genes filtering data using GSE39396.

Results

The analysis of differentially expressed genes of stroma/tumour glands from responder and non-responder patients shows that most changes were associated with the stromal compartment; codifying mainly for extracellular matrix and ribosomal components. We built a carcinoma-associated fibroblast (CAF) specific classifier with genes showing changes in expression according to the tumour regression grade (FN1, COL3A1, COL1A1, MMP2 and IGFBP5). We assessed these five genes at the protein level by means of immunohistochemical staining in a patient's cohort (n = 38). For predictive purposes we used a leave-one-out cross-validated model with a positive predictive value (PPV) of 83.3%. Random Forest identified FN1 and COL3A1 as the best predictors. Rebuilding the leave-one-out cross-validated regression model improved the classification performance with a PPV of 93.3%. An independent cohort was used for classifier validation (n = 36), achieving a PPV of 88.2%. In a multivariate analysis, the two-protein classifier proved to be the only independent predictor of response.

Conclusion

We developed a two-protein immunohistochemical classifier that performs well at predicting the non-response to neoadjuvant treatment in rectal cancer.

Extracolonic Cancer in Inflammatory Bowel Disease: Data from the GETECCU Eneida Registry

OBJECTIVES

The objective of this study was (a) To know the prevalence and distribution of extracolonic cancer (EC) in patients with inflammatory bowel disease (IBD); (b) To estimate the incidence rate of EC; (c) To evaluate the association between EC and treatment with immunosuppressants and anti-tumor necrosis factor (TNF) agents.

METHODS

This was an observational cohort study.

INCLUSION CRITERIA

IBD and inclusion in the ENEIDA Project (a prospectively maintained registry) from GETECCU.

EXCLUSION CRITERIA

Patients with EC before the diagnosis of IBD, lack of relevant data for this study, and previous treatment with immunosuppressants other than corticosteroids, thiopurines, methotrexate, or anti-TNF agents. The Kaplan-Meier method was used to evaluate the impact of several variables on the risk of EC, and any differences between survival curves were evaluated using the log-rank test. Stepwise multivariate Cox regression analysis was used to investigate factors potentially associated with the development of EC, including drugs for the treatment of IBD, during follow-up.

RESULTS

A total of 11,011 patients met the inclusion criteria and were followed for a median of 98 months. Forty-eight percent of patients (5,303) had been exposed to immunosuppressants or anti-TNF drugs, 45.8% had been exposed to thiopurines, 4.7% to methotrexate, and 21.6% to anti-TNF drugs. The prevalence of EC was 3.6%. In the multivariate analysis, age (HR=1.05, 95% CI=1.04-1.06) and having smoked (hazards ratio (HR)=1.47, 95% confidence interval (CI)=1.10-1.80) were the only variables associated with a higher risk of EC.

CONCLUSIONS

Neither immunosuppressants nor anti-TNF drugs seem to increase the risk of EC. Older age and smoking were associated with a higher prevalence of EC.

Randomised clinical trial: colestyramine vs. hydroxypropyl cellulose in patients with functional chronic watery diarrhoea

BACKGROUND

Idiopathic bile acid malabsorption (BAM) has been suggested as a cause of chronic watery diarrhoea, with a response to colestyramine in 70% of patients. However, the efficacy of this drug has never been investigated in placebo-controlled trials.

AIM

To evaluate the efficacy of colestyramine as compared with hydroxypropyl cellulose in the treatment of functional chronic watery diarrhoea.

METHODS

Patients with chronic watery diarrhoea were randomly assigned to groups given colestyramine sachets 4 g twice daily (n = 13) or identical hydroxypropyl cellulose sachets (n = 13) for 8 weeks. The primary end-point was clinical remission defined as a mean of 3 or fewer stools per day during the week before the visit, with less than 1 watery stool per day. A secondary end-point was the reduction in daily watery stool number. SeHCAT test was performed in all patients, but an abnormal test was not a prerequisite to be included.

RESULTS

All included patients had a SeHCAT 7-day retention ≤20%. There were no statistical differences in the percentage of patients in clinical remission at week 8 between colestyramine and hydroxypropyl cellulose with either intention-to-treat (53.8% vs. 38.4%; P = 0.43) or per-protocol (63.6% vs. 38.4%; P = 0.22) analyses. However, the mean per cent decrease in watery stool number was significantly higher with colestyramine than with hydroxypropyl cellulose (-92.4 ± 3.5% vs. -75.8 ± 7.1%; P = 0.048). The rate of adverse events related to study drugs did not differ between groups.

CONCLUSIONS

Colestyramine (4 g twice daily) is effective and safe for short-term treatment of patients with chronic watery diarrhoea presumably secondary to BAM. Clinical Trials Register number EudraCT 2009-011149-14.

Comparison of the long-term outcome of two therapeutic strategies for the management of abdominal abscess complicating Crohn's disease: percutaneous drainage or immediate surgical treatment

AIM

The management of abdominal abscesses complicating Crohn's disease is complex and involves a difficult choice between medical, radiological and surgical procedures. The long-term outcome was compared for two strategies for the management of abdominal abscess: percutaneous drainage (PD) followed by rescue surgery in the case of failure vs direct immediate surgery (IS). We also compared the results of IS with surgery performed after PD failure.

METHODS

We retrospectively identified 44 patients with Crohn's disease with an abdominal abscess from January 2000 to December 2009. Therapeutic success was defined as abscess resolution and no reappearance within 1 year of follow-up.

RESULTS

The first therapeutic approach was PD in 22 cases and IS in the other 22 cases. IS had a higher therapeutic success rate than PD (95.5% vs 27.2% respectively; P < 0.001). PD was the only independent variable related to treatment failure in the multivariate analysis after adjustment for possible confounders such as abscess size, multilocularity, presence of fistula and corticosteroid use (OR 88.26, 95% CI 7.38-1055.36; P < 0.001). Surgery after failure of PD (n = 16) was associated with longer total hospitalization (56.12 ± 35.89 vs 27.52 ± 15.11 days; P = 0.017) and longer postoperative stay (44.0 ± 83.7 vs 14.3 ± 30 days; P = 0.179) and needed a second operation more often (5/16, 31% vs 1/22, 4.5%; P = 0.065) than IS.

CONCLUSIONS

Percutaneous drainage provided durable abscess resolution in only one-third of the patients compared with more than 90% of those treated with IS. In addition, surgery performed after PD failure results in a poorer outcome than IS.

A model that links growth and secondary metabolite production in plant cell suspension cultures

Plant cell suspensions of grape cells (Vitis vinifera L. cv. Gamay Fréaux) were grown in shake flasks operated both in the batch and semicontinuous mode. A mathematical model was developed to describe grape cell growth, sucrose uptake, and secondary metabolite (anthocyanin) production. Parameters were estimated from batch studies data. The model was able to predict results for semicontinuous experiments by only modifying the value of four of these parameters. The modified parameters (maximum specific rate of biomass production, maximum specific rate of substrate consumption for maintenance, maximum specific rate of anthocyanin production, and degradation constant of anthocyanins) were related to the kinetics rather than to the yield of the process. The model introduces the concept of primary and secondary metabolism substrate concentration-dependent competition for precursors. Further, the model was able to predict the evolution of the cell system when substrate is scarce, as the value of the different kinetic constants determines the portion of substrate that is used for biomass production, secondary metabolite production, and cell maintenance. (c) 1995 John Wiley & Sons, Inc.

[Measurement of 75Se-SeHCAT abdominal retention in the initial diagnosis of Bile Acid Absorption (BAM)]

AIM

To evaluate the usefulness of the (75)SeHCAT abdominal retention (AR) measurement in the early diagnosis of diarrhea syndrome (DS).

METHODS

Thirty-seven patients with diarrhea syndrome within the first month of evolution were prospectively evaluated. The (75)Se-SeHCAT abdominal retention was measured 4 and 7 days post-administration of 0.01 mCi of (75)SeHCAT. The test was performed prior to treatment and at 3 months when the baseline study was positive. The test was considered positive if the RA was <25% at 4(th) and <10% on the 7th day. The patients were visited at 3 months. Depending on the response, 3 groups were established: a) complete response: normalization of stool frequency, b) partial response, decrease of frequency or c) no response.

RESULTS

Group A: The AR of (75)Se-SEHCAT was normal in 21 patients. Six were diagnosed of colonic diverticulosis, 8 of irritable bowel syndrome, 1 of lymphocytic colitis, 1 of post-gastroenteritis syndrome, 1 of celiac disease and 1 of stenosis of the cardia. Four are still under study. Group B: The AR of (75)Se-SEHCAT decreased in 16 patients. All showed abnormal AR at day 7 and all but 1 at day 4. Following administration of cholestyramine resin, 8 (50%) presented partial response and 8 (50%) complete response. At 3 months, AR had increased at day 4 and 9 at day 7.

CONCLUSION

The measurement of (75)SEHCAT abdominal retention allows the early diagnosis of bile acid malabsorption in 43% of the patients with DS. Measurement at 7 days seems more accurate than that at 4 days.

Predicting mortality in hospitalized patients with 2009 H1N1 influenza pneumonia

BACKGROUND

Community-acquired pneumonia (CAP) severity scores can identify patients at low risk for mortality who may be suitable for ambulatory care. Here, we follow the clinical course of hospitalized patients with CAP due to 2009 H1N1 influenza.

OBJECTIVE

To evaluate the role of CAP severity scores as predictors of mortality.

METHODS

This was a secondary data analysis of patients hospitalized with CAP due to 2009 H1N1 influenza confirmed by reverse transcriptase polymerase chain reaction enrolled in the CAPO (Community-Acquired Pneumonia Organization) international cohort study. CAP severity scores PSI (Pneumonia Severity Index), CURB-65 (confusion, urea, respiratory rate, blood pressure, age ≥ 65 years) and CRB-65 (confusion, respiratory rate, blood pressure, age ≥ 65 years) were calculated. Actual and predicted mortality rates were compared. A total of 37 predictor variables were evaluated to define those associated with mortality.

RESULTS

Data from 250 patients with CAP due to 2009 H1N1 influenza were analyzed. Patients with low predicted mortality rates (0-1.5%) had actual mortality rates ranging from 2.6% to 17.5%. Obesity and wheezing were the only novel variables associated with mortality.

CONCLUSIONS

The decision to hospitalize a patient with CAP due to 2009 H1N1 influenza should not be based on current CAP severity scores, as they underestimate mortality rates in a significant number of patients. Patients with obesity or wheezing should be considered at an increased risk for mortality.

Evaluation of stool melting curve analysis of methylated CpG island promoters as an alternative for early noninvasive diagnosis of colorectal tumors

e15036

Background: Previous studies have shown that assessment of promoter hypermethylation of a limited number of genes in tumor biopsies may identify all colorectal tumors analyzed. The aim of the present study was to assess the clinical usefulness of a panel of methylation biomarkers in stool DNA in the diagnosis of colorectal tumors using Methylation Curve (MC) analyses, a technique that simultaneously analyze all CpG residues within a promoter. Methods: Promoter methylation status of 5 tumor-related genes (RARB2, p16INK4a, MGMT, p14ARF and APC) was analyzed in DNA stool samples and corresponding tissues in an initial set of 12 newly diagnosed patients with primary colorectal carcinomas and 20 with colorectal adenomas using Methylation-specific PCR (MSP). Results were validated in a set of 88 patients (20 healthy subjects, 17 inflammatory bowel disease, 23 adenomas, 28 carcinomas) using MC analyses. Median age for every group was 63, 51, 66 and 67 y respectively. Results: In the initial set, the majority [10 of 12 (83%) carcinomas and 18 of 20 (90%) adenomas] of biopsies were positive for at least one marker. In stool DNA prevalence was 75% for carcinomas (9 of 12) and 60% for adenomas (12 of 20) with no false positive in stools. In the validation set MC was used. Analytical sensitivity of MC was 5% of methylated alleles for p16INK4a, p14ARF, RARB2 and APC and 10% for MGMT. In the validation set MC analyses of biopsies showed that at least one marker was positive in 22 of 28 (79%) carcinomas and 16 of 23 (70%) adenomas. In stool DNA, these percentages were 64% (18 of 28) for carcinomas and 42% (9 of 23) for adenomas. No aberrant methylation was observed in healthy subjects and in 2 of 15 (13%) of IBD patients aberrant RARB2 methylation was detected. Conclusions: Melting Curve analysis of a panel of methylation markers in stool DNA is a good alternative for the early non-invasive diagnosis of colorectal tumors.

[Table: see text]

Inflammatory mechanisms in the lung

Inflammation is the body's response to insults, which include infection, trauma, and hypersensitivity. The inflammatory response is complex and involves a variety of mechanisms to defend against pathogens and repair tissue. In the lung, inflammation is usually caused by pathogens or by exposure to toxins, pollutants, irritants, and allergens. During inflammation, numerous types of inflammatory cells are activated. Each releases cytokines and mediators to modify activities of other inflammatory cells. Orchestration of these cells and molecules leads to progression of inflammation. Clinically, acute inflammation is seen in pneumonia and acute respiratory distress syndrome (ARDS), whereas chronic inflammation is represented by asthma and chronic obstructive pulmonary disease (COPD). Because the lung is a vital organ for gas exchange, excessive inflammation can be life threatening. Because the lung is constantly exposed to harmful pathogens, an immediate and intense defense action (mainly inflammation) is required to eliminate the invaders as early as possible. A delicate balance between inflammation and anti-inflammation is essential for lung homeostasis. A full understanding of the underlying mechanisms is vital in the treatment of patients with lung inflammation. This review focuses on cellular and molecular aspects of lung inflammation during acute and chronic inflammatory states.

Pneumonia due to Nocardia cyriacigeorgica in a patient with Crohn's disease treated with infliximab

Infliximab, an anti-tumor necrosis factor α (TNF-α) antibody, is useful in the treatment of rheumatoid arthritis, Crohn's disease etc. It has been related to increases in the rate of several infections. We present the case of a 53-year-old woman diagnosed with community-acquired pneumonia due to Nocardia cyriacigeorgica who was taking infliximab, azathioprine and prednisone for Crohn's disease.

Airway mechanoreceptor deactivation

Airway sensors play an important role in control of breathing. Recently, it was found that pulmonary slowly adapting stretch receptors (SARs) cease after a brief excitation following sodium pump blockade by ouabain. This deactivation can be explained by overexcitation. If this is true, mechanical stimulation of the SARs should also lead to a deactivation. In this study, we recorded unit activity of the SARs in anesthetized, open-chest, and mechanically ventilated rabbits and examined their responses to lung inflation at different constant pressures. Forty-seven of 137 units had a clear deactivation during the lung inflation. The deactivation threshold varied from unit to unit. For a given unit, the higher the inflation pressure, the sooner the deactivation occurs. For example, the SARs deactivated at 3.0 +/- 0.3 and 4.8 +/- 0.4 s when the lungs were inflated to constant pressures of 30 and 20 cmH(2)O, respectively (n = 25, P < 0.0001). The units usually ceased after a brief intense discharge. In some units, their activity shifted to a lower level, indicating a pacemaker switching. Our results support the notion that SARs deactivate due to overexcitation.

Utilidad pronóstica de la gammagrafía con leucocitos marcados 99mTc-HMPAO en la enfermedad inflamatoria intestinal

OBJECTIVE

The inflammatory bowel disease (EII) has a chronic evolution with a frequent relapses. There is no specific diagnosis method to detect the patients with a high risk to relapse. The aim of the work was to analyse the prognostic value of 99mTc-HMPAO leukocyte scintigraphy (LS) performed during an acute attack of EII.

MATERIAL AND METHODS

18 patients (mean age 32 +/- 10 years) admitted for an acute attack of EII has been prospectively studied (5 ulcerative colitis [UC] and 13 Cronh's disease [CD]), excluding patient with prior steroids or immunosuppressive therapy during the last year. LS were obtained in basal conditions and following 3 weeks of steroid treatment and the scintigraphic activity index (SAI) has been calculated. Colonoscopy has been done in all patients, and CDAI in CD and Truelove index in UC have been calculated. Patients were followed up for 1 year. In the evolution the therapy requirements as well as the good response to initial treatment have been evaluated.

RESULTS

All patients with UC and 4 patients with CD showed a SAI decrease > 50 % and all had a good clinical evolution. Only 2 out of the 9 patients with CD showing a IAG decrease < 50 % and had a good clinical evolution, the 7 remaining required additional medical treatment (immunosuppressors or surgery).

CONCLUSION

LS may be of prognostic value in the management of EII. A SAI decrease > 50 % at 3 weeks of steroid treatment indicates a good clinical evolution.

Pulmonary sensory and reflex responses in the mouse

Mouse model research is proliferating because of its readiness for genetic manipulation. Little is known about pulmonary vagal afferents in mice, however. The purpose of this study was to determine whether their pulmonary afferents are similar to those in large animals. Single-unit activity was recorded in the cervical vagus nerve of anesthetized, open-chest, and mechanically ventilated mice. We evaluated airway sensory activity in 153 single units; 141 were mechanosensitive, with 134 inflation receptors and 7 deflation receptors. The remaining 12 receptors were chemosensitive and mechanically insensitive, showing low basal firing frequency and behaving like C-fiber or high-threshold Adelta-receptors. In separate studies, phrenic activity was recorded as an index of respiratory drive to assess pulmonary reflexes. Lung inflation produced a typical Hering-Breuer reflex, and intravenous injection of phenylbiguanide produced the typical chemoreflex resulting in apnea, bradycardia, and hypotension. These reflexes were blocked by bilateral vagotomy. We conclude that mice possess a similar set of airway sensors and pulmonary reflexes as typically found in larger animals.

7-day rescue therapy with ranitidine bismuth citrate after Helicobacter pylori treatment failure

BACKGROUND

Quadruple rescue therapy requires a complex scheme with four drugs.

AIM

To evaluate the efficacy of ranitidine bismuth citrate-tetracycline-metronidazole rescue regimen, and to compare two different metronidazole dose schemes.

METHODS

Prospective multicentre study including proton-pump inhibitor + clarithromycin + amoxicillin failures. Rescue regimen included two 7-day treatment: (i) ranitidine bismuth citrate (400 mg b.d.)-tetracycline (500 mg q.d.s.)-metronidazole (500 mg t.d.s.; RTM1); or (ii) the same regimen but with metronidazole 250 mg q.d.s. (RTM2). Eradication was confirmed with (13)C-urea breath test.

RESULTS

A total of 150 patients were included (58 RTM1, 92 RTM2). All patients but two (one in each group) returned after treatment. About 86% in group RTM1 and 95% in RTM2 correctly took all the medications (P = 0.076). Per-protocol eradication rates with RTM1 and RTM2 were 74 (95% CI: 60-84) and 69% (59-78). The intention-to-treat eradication rates were 64 (51-75) and 70% (59-78; P > 0.05). The type of regimen was not associated with eradication in the multivariate analysis. Adverse effects were more frequent with RTM1 (41%) than with RTM2 (30%; P > 0.05).

CONCLUSION

Seven-day triple rescue therapy with ranitidine bismuth citrate-tetracycline-metronidazole is effective for Helicobacter pylori eradication, and represents an encouraging alternative to quadruple therapy, with the advantage of simplicity. The administration of metronidazole every 6 h (together with tetracycline), and at a low dose (250 mg), achieves similar efficacy and is probably associated with a better compliance and a lower incidence of adverse effects.

Light and electron microscopic analysis of liver biopsy samples from rheumatoid arthritis patients receiving long-term methotrexate therapy

OBJECTIVE

We study liver damage in forty-two patients with rheumatoid arthritis (RA) using light (LM) and electron microscopy (EM) and assess histological changes after four years of treatment with methotrexate (MTX).

PATIENTS AND METHODS

liver biopsies (LB) were taken before and after four years of treatment. Patients received weekly doses of between 7.5-15 mg of MTX.

RESULTS

Fourteen per cent of the baseline LB presented mild perisinusoidal fibrosis (Roenigk IIIA) and the rest a lower Roenigk grade; EM identified an increase in collagen fibers in the Disse spaces in 50% of baseline LB. Neither microscopy technique revealed histological progression in any of the sequential LB. Variables that correlated with histological abnormalities were patient's age, length of evolution of the disease, alcohol consumption and biochemical data (gammaglutamate transferase and albumin); the cumulative dose of MTX was not correlated with worse histological findings. Correlation between the two microscopy techniques was good, though EM was more sensitive than LM for the detection of fibrosis.

CONCLUSIONS

RA patients present with liver damage before treatment with MTX. The alterations are mild. At low doses MTX treatment is safe. In addition to the recommendations of the American College of Rheumatology, other factors associated with liver impairment are patient's age and length of evolution of the RA.

One-week triple vs. quadruple therapy for Helicobacter pylori infection - a randomized trial

BACKGROUND

Seven-day triple therapy including omeprazole, clarithromycin and amoxicillin has become the treatment of choice for Helicobacter pylori infection. However, 7 days of classical quadruple therapy combining omeprazole, tetracycline, metronidazole and bismuth may be an alternative to triple therapy.

AIM

To compare triple vs. quadruple therapy for H.pylori eradication.

METHODS

Three hundred and thirty-nine patients with peptic ulcer and H. pylori infection were included in the study. Patients were randomized to receive omeprazole, 20 mg, amoxicillin, 1 g, and clarithromycin, 500 mg, all b.d., or omeprazole, 20 mg b.d., tetracycline chloride, 500 mg, metronidazole, 500 mg, and bismuth subcitrate, 120 mg, all t.d.s. Cure was defined as a negative urea breath test at least 2 months after treatment.

RESULTS

Per protocol and intention-to-treat cure rates were 86%[95% confidence interval (CI), 80-91%] and 77% (95% CI, 70-83%) for triple therapy, and 89% (95% CI, 82-93%) and 83% (95% CI, 76-88%) for quadruple therapy. No significant differences between the groups were found in the cure rates, compliance or side-effects.

CONCLUSION

One-week triple and quadruple therapy show similar results when used as first-line eradication treatment.

Risk factors for development of de novo neoplasia after liver transplantation

Liver transplant recipients are at greater risk for de novo neoplasia, especially lymphoma and nonmelanoma skin cancer; however, risk factors for this complication have not been well studied. Clinical and pathological records of 137 consecutive liver transplant recipients who had survived for at least 1 year were reviewed to register de novo neoplasia. Ten variables were analyzed for their association with the development of de novo malignancies by means of a log-rank test and stepwise selection in a multivariate analysis using the Cox proportional hazard model. Thirty de novo neoplasias appeared in 22 of 137 transplant recipients between 12 and 104 months after orthotopic liver transplantation (OLT; median follow-up, 69 months): 14 patients had 21 skin cancers, 6 patients had solid-organ cancer, and 3 patients developed a lymphoproliferative disease. Probabilities of de novo neoplasia were 13% at 5 years post-OLT and 26% at 8 years post-OLT. The only associated risk factor for any neoplasia was age. Age and hepatocarcinoma were independent risk factors associated with skin cancer. That hepatocarcinoma in the explanted liver is an independent risk factor for skin cancer suggests there is individual susceptibility to both neoplasias.

Design of cassette vectors permitting cloning of all types of human TCR variable alpha and beta regions

T cell clones are an irreplaceable asset for the study of immune responses relevant to human pathologies. Such cells, however, cannot always be maintained in long-term culture. In order to reconstitute functional human T cell receptors (TCRs) into stable and fast growing hybridoma T cells, we developed a general approach based on a versatile cassette system, which allows cloning of all types of human T cell receptor variable alpha and beta region genes fused to murine constant regions. These chimeric constructs are easily excised and transferred into expression vectors that can be used to transfect a human CD4-expressing murine T cell hybridoma recipient. The resulting transfectants are highly stable both in terms of T cell receptor-CD3 expression and IL-2 response to the specific antigenic stimulus. Using these cassette vectors, we reconstituted the original HLA-restricted antigen specificity for two human T cell clones, one recognizing an immunodominant epitope of HIV-1 gp120, and the other recognizing an immunodominant epitope of HIV-1 reverse transcriptase. We found that the reconstituted hybridomas maintain the ability of the original T cell clones to recognize the appropriate epitope in the context of the relevant MHC either as a synthetic peptide or after processing. Their unlimited growth capacity makes them particularly suited for in vitro studies.

Rapid urease test: effect of preimmersion of biopsy forceps in formalin

OBJECTIVE

The rapid urease test is widely used at endoscopy to determine the presence of Helicobacter pylori. The effect of immersion of the biopsy forceps in formalin before performance of a rapid urease test is uncertain. The aim of this prospective study was to determine whether previous immersion of the biopsy forceps in formalin influences rapid urease test results.

METHODS

Two hundred fifty-three consecutive patients undergoing upper GI endoscopy with a clinical indication for rapid urease test had two tests with two different antral mucosa biopsies. The former was performed with a sterile biopsy forceps, the latter with a sterile biopsy forceps that was previously immersed in 10% buffered formalin. In 132 patients the CLOtest was used and in 121 patients the Jatrox-H.P. test was used. The kappa concordance test was used for comparisons.

RESULTS

In the 132 patients in which the CLOtest was used, both were positive in 76 cases, both negative in 27, and discordant results were seen in 3 cases (2.27%), kappa 0.953 (range 0.901-1.000, p < 0.001). In the 121 patients in which the Jatrox test was used, both were positive in 89, both negative in 27 and there were 5 (4.13%) discordant cases, kappa 0.880 (0.793-0.984, p < 0.001). There were no differences in positivity rates at 30 minutes, 1 hour, and 3 hours between the two rapid urease test kits.

CONCLUSION

Preimmersion of the biopsy forceps in formalin does not adversely affect the rapid urease test.

Unbalanced expression of HLA-A and -B antigens: a specific feature of cutaneous melanoma and other non-hemopoietic malignancies reverted by IFN-gamma

Conflicting evidences suggested that levels of HLA-A and -B antigens expressed on normal and neoplastic cells of given individuals are genetically predetermined, or, on the other hand, regulated by molecular mechanisms generating the down-regulated expression of HLA-B antigens frequently observed on melanoma cells. In our study, we quantitated, both at the protein and mRNA level, the amounts of HLA-A and -B antigens constitutively expressed on 23 primary cultures of metastatic melanomas and on autologous peripheral blood mononuclear cells (PBMC). Flow cytometric analyses identified a significantly (p < 0.01) lower expression of HLA-B antigens on melanoma cell cultures but not on autologous PBMC. Consistently, lower amounts of HLA-B antigens mRNA were detected by RNase protection assay exclusively in neoplastic cells. This unbalanced expression of HLA-A and -B antigens was readily reverted by interferon (IFN)-gamma but not by the DNA hypomethylating agent 5-aza-2'-deoxycytidine in 4 melanoma cell cultures investigated. Significantly (p < 0.05) lower levels of HLA-B antigens were also detected on cells from solid malignancies of different histotypes but not on neoplastic cells from hemopoietic neoplasms; levels of HLA-B antigens were rapidly up-regulated by IFN-gamma exclusively on non-hemopoietic transformed cells. Together, these data strongly argue against a genetic predetermination of the amounts of HLA-A and -B antigens expressed on normal and neoplastic cells of distinct melanoma patients and suggest that constitutively low levels of HLA-B antigens are a specific feature of non-hemopoietic transformed cells that is controlled by common regulatory mechanism(s) and that is possibly shared by non-hemopoietic normal cells.

Phage display of peptide epitopes from HIV-1 elicits strong cytolytic responses

Although much effort has been expended on evaluating recombinant proteins and synthetic peptides as immunogens, they have generally proved incapable of inducing an efficient cytotoxic T-cell (CTL) response. Filamentous bacteriophage fd can display multiple copies of foreign peptides in the N-terminal region of its major coat protein pVIII, 2,700 copies of which make up the virus capsid. Here we show that fd virions displaying peptide RT2 (ILKEPVHGV), corresponding to residues 309-317 of the reverse transcriptase (RTase) of HIV-1, are able to prime a CTL response specific for this HIV-1 epitope in human cell lines. Successful priming also requires a T-helper epitope, pep23 (KDSWTVNDIQKLVGK), corresponding to residues 249-263 of HIV-1 RTase. Supplying this by displaying it on either the same or a separate bacteriophage virion led to activation of antigen-specific CD4+ T cells. Likewise, HLA-A2 transgenic mice immunized with bacteriophage virions displaying peptide RT2 were shown to mount an effective, specific anti-HIV-RT2 CTL response. This unexpected ability to elicit a designated cytolytic T-cell response, in addition to a B-cell response, has important implications for access to the class I major histocompatibility complex (MHC) loading compartment and the development of recombinant vaccines.

Modulation of TCR recognition of MHC class II/peptide by processed remote N- and C-terminal epitope extensions

N- and C-terminal extensions of naturally processed MHC class II-bound peptides may affect TCR recognition. In fact, residues immediately flanking the minimal epitope on either side can contact the MHC groove and modify the interaction with a TCR. We report now that residues much farther away from the peptide core can also modulate TCR recognition in a functional antigen presentation system. To show this, we isolated from the same donor DR5-restricted T cell clones, specific for the HIV-1 RT(248-262) sequence and differing in their ability to respond to recombinant antigens obtained by insertion of the epitope in different positions of schistosomal, human, or murine glutathione-S-transferase (GST). We found that the reactivity profile of individual clones was related to their TCR fine specificity, suggesting that processing can generate determinants focused onto the same epitope, but antigenically distinct. In addition, we analyzed the response of this panel of T-helper cell clones against GST-derived recombinant antigens in which the epitope was flanked by stretches of polyalanine or polyserine on either side. These spacers had different effects on TCR recognition suggesting that secondary structures outside the core peptide may influence MHC/epitope complex recognition over a distance of 15-30 residues from the determinant.

Identification of a new subset of cells exhibiting dendritic phenotypes in patients affected by breast proliferative disorders

We report that a subset of circulating cells reacting with a monoclonal antibody raised against a protein marker is significantly increased in the peripheral blood of women carrying benign or malignant breast diseases, particularly in patients under 55 years of age with ductal mammary carcinomas. These cells were statistically (confidence level of 99%) less represented in a control population including healthy women or women carrying carcinomas of origin other than breast. Double staining analysis showed that they harbor markers of dendritic cells and exhibit endo- cytic activity, as determined by their ability to internalize FITC-dextran particles. Their dendritic morphology was further demonstrated by electron microscopy of sorted antibody-positive cells. However, expression of surface molecules, such as CD34 and CD14, usually not present in differentiated populations of dendritic cells was also observed. Adherent cells of patients with breast ductal carcinoma including mostly cells of this new subset were efficient stimulators of mixed lymphocyte reaction, attaining maximal stimulatory activity attained after TNFalpha treatment. In conclusion, we have shown that a subset of cells characterized by a phenotype suggestive of a yet undescribed stage of maturation of the dendritic cell lineage is accumulated in the blood of patients affected by breast proliferative disorders.

Mapping the CD4 binding domain of gp17, a glycoprotein secreted from seminal vesicles and breast carcinomas

gp17, a secretory CD4-binding factor isolated from the human seminal plasma, is identical to the gross cystic disease fluid protein-15, a specific marker for primary and metastatic breast tumors. We previously demonstrated that gp17 binds to CD4 with high affinity and strongly inhibits T lymphocyte apoptosis induced by sequential cross-linking of CD4 and T cell receptor (TCR). To further characterize the gp17/CD4 interaction and map the gp17 binding site, we produced a secreted form of recombinant gp17 fused to human IgG1 Fc, gp17-Ig. We showed that gp17-Ig exhibits a binding affinity for CD4 similar to that of native gp17. As no information about gp17 structure is presently available, 99 overlapping gp17 peptides were synthesized by the Spot method, which allowed the mapping of two CD4 binding regions. Alanine scanning of CD4-reactive peptides identified critical residues, selected for site-directed mutagenesis. Nine gp17-Ig mutants were generated and characterized. Three residues within the carboxy-terminal region were identified as the major binding domain to CD4. The Spot method combined with mutagenesis represents a refined approach to distinguish the contact residues from the ones contributing to the conformation of the CD4-binding domain.

A novel aspartyl proteinase from apocrine epithelia and breast tumors

GCDFP-15 (gross cystic disease fluid protein, 15 kDa) is a secretory marker of apocrine differentiation in breast carcinoma. In human breast cancer cell lines, gene expression is regulated by hormones, including androgens and prolactin. The protein is also known under different names in different body fluids such as gp17 in seminal plasma. GCDFP-15/gp17 is a ligand of CD4 and is a potent inhibitor of T-cell apoptosis induced by sequential CD4/T-cell receptor triggering. We now report that GCDFP-15/gp17 is a protease exhibiting structural properties relating it to the aspartyl proteinase superfamily. Unexpectedly, GCDFP-15/gp17 appears to be related to the retroviral members rather than to the known cellular members of this class. Site-specific mutagenesis of Asp(22) (predicted to be catalytically important for the active site) and pepstatin A inhibition confirmed that the protein is an aspartic-type protease. We also show that, among the substrates tested, GCDFP-15/gp17 is specific for fibronectin. The study of GCDFP-15/gp17-mediated proteolysis may provide a handle to understand phenomena as diverse as mammary tumor progression and fertilization.

A prognostic index of the survival of patients with unresectable hepatocellular carcinoma after transcatheter arterial chemoembolization

BACKGROUND

Transcatheter arterial chemoembolization (TACE) has been used as a palliative treatment for patients with unresectable hepatocellular carcinoma (HCC), but its prognostic usefulness has not previously been clarified.

METHODS

The authors reviewed all patients treated at their institution with TACE for unresectable HCC in order to analyze prognostic factors and to determine which patients might benefit from this treatment. One hundred forty-three patients were retrospectively studied. Pretreatment, treatment, and follow-up variables with possible prognostic significance were analyzed. A stepwise multivariate analysis was performed using the Cox regression model, and a prognostic index was obtained.

RESULTS

According to univariate analysis, variables significantly associated with survival were alpha-fetoprotein (>400 U/L), tumor size (>50%), ascites, albumin (<30 g/L), Child-Pugh grade (Child C), Okuda stage (Okuda III), portal vein thrombosis, tumor greatest dimension larger than 5 cm, more than 3 nodules, bilobular involvement, and pattern of iodized oil uptake, tumor size reduction, and radiologic T classification on computed tomography scan performed 7 and 30 days after TACE. However, only ascites, alpha-fetoprotein (>400 U/L), tumor size (>50%), Child-Pugh grade (Child C), pattern of iodized oil uptake, and portal vein thrombosis were independent factors in multivariate analysis. Using the beta-coefficients of alpha-fetoprotein (>400 U/L), tumor size (>50%) and Child-Pugh score, a prognostic index was calculated, and according to this index patients were classified into 3 categories with different prognoses. Ascites was excluded from the analysis because it is included in Child-Pugh grade, and iodized oil uptake was excluded because it cannot be evaluated before treatment.

CONCLUSIONS

This simple prognostic index can predict the survival of patients treated with TACE and can therefore be used to decide which patients with unresectable HCC should receive this therapy. TACE should not be administered to patients with one or more positive prognostic factors.

A prognostic index of the survival of patients with unresectable hepatocellular carcinoma after transcatheter arterial chemoembolization

BACKGROUND

Transcatheter arterial chemoembolization (TACE) has been used as a palliative treatment for patients with unresectable hepatocellular carcinoma (HCC), but its prognostic usefulness has not previously been clarified.

METHODS

The authors reviewed all patients treated at their institution with TACE for unresectable HCC in order to analyze prognostic factors and to determine which patients might benefit from this treatment. One hundred forty-three patients were retrospectively studied. Pretreatment, treatment, and follow-up variables with possible prognostic significance were analyzed. A stepwise multivariate analysis was performed using the Cox regression model, and a prognostic index was obtained.

RESULTS

According to univariate analysis, variables significantly associated with survival were alpha-fetoprotein (>400 U/L), tumor size (>50%), ascites, albumin (<30 g/L), Child-Pugh grade (Child C), Okuda stage (Okuda III), portal vein thrombosis, tumor greatest dimension larger than 5 cm, more than 3 nodules, bilobular involvement, and pattern of iodized oil uptake, tumor size reduction, and radiologic T classification on computed tomography scan performed 7 and 30 days after TACE. However, only ascites, alpha-fetoprotein (>400 U/L), tumor size (>50%), Child-Pugh grade (Child C), pattern of iodized oil uptake, and portal vein thrombosis were independent factors in multivariate analysis. Using the beta-coefficients of alpha-fetoprotein (>400 U/L), tumor size (>50%) and Child-Pugh score, a prognostic index was calculated, and according to this index patients were classified into 3 categories with different prognoses. Ascites was excluded from the analysis because it is included in Child-Pugh grade, and iodized oil uptake was excluded because it cannot be evaluated before treatment.

CONCLUSIONS

This simple prognostic index can predict the survival of patients treated with TACE and can therefore be used to decide which patients with unresectable HCC should receive this therapy. TACE should not be administered to patients with one or more positive prognostic factors.

A prognostic index of the survival of patients with unresectable hepatocellular carcinoma after transcatheter arterial chemoembolization

BACKGROUND

Transcatheter arterial chemoembolization (TACE) has been used as a palliative treatment for patients with unresectable hepatocellular carcinoma (HCC), but its prognostic usefulness has not previously been clarified.

METHODS

The authors reviewed all patients treated at their institution with TACE for unresectable HCC in order to analyze prognostic factors and to determine which patients might benefit from this treatment. One hundred forty-three patients were retrospectively studied. Pretreatment, treatment, and follow-up variables with possible prognostic significance were analyzed. A stepwise multivariate analysis was performed using the Cox regression model, and a prognostic index was obtained.

RESULTS

According to univariate analysis, variables significantly associated with survival were alpha-fetoprotein (>400 U/L), tumor size (>50%), ascites, albumin (<30 g/L), Child-Pugh grade (Child C), Okuda stage (Okuda III), portal vein thrombosis, tumor greatest dimension larger than 5 cm, more than 3 nodules, bilobular involvement, and pattern of iodized oil uptake, tumor size reduction, and radiologic T classification on computed tomography scan performed 7 and 30 days after TACE. However, only ascites, alpha-fetoprotein (>400 U/L), tumor size (>50%), Child-Pugh grade (Child C), pattern of iodized oil uptake, and portal vein thrombosis were independent factors in multivariate analysis. Using the beta-coefficients of alpha-fetoprotein (>400 U/L), tumor size (>50%) and Child-Pugh score, a prognostic index was calculated, and according to this index patients were classified into 3 categories with different prognoses. Ascites was excluded from the analysis because it is included in Child-Pugh grade, and iodized oil uptake was excluded because it cannot be evaluated before treatment.

CONCLUSIONS

This simple prognostic index can predict the survival of patients treated with TACE and can therefore be used to decide which patients with unresectable HCC should receive this therapy. TACE should not be administered to patients with one or more positive prognostic factors.

A prognostic index of the survival of patients with unresectable hepatocellular carcinoma after transcatheter arterial chemoembolization

BACKGROUND

Transcatheter arterial chemoembolization (TACE) has been used as a palliative treatment for patients with unresectable hepatocellular carcinoma (HCC), but its prognostic usefulness has not previously been clarified.

METHODS

The authors reviewed all patients treated at their institution with TACE for unresectable HCC in order to analyze prognostic factors and to determine which patients might benefit from this treatment. One hundred forty-three patients were retrospectively studied. Pretreatment, treatment, and follow-up variables with possible prognostic significance were analyzed. A stepwise multivariate analysis was performed using the Cox regression model, and a prognostic index was obtained.

RESULTS

According to univariate analysis, variables significantly associated with survival were alpha-fetoprotein (>400 U/L), tumor size (>50%), ascites, albumin (<30 g/L), Child-Pugh grade (Child C), Okuda stage (Okuda III), portal vein thrombosis, tumor greatest dimension larger than 5 cm, more than 3 nodules, bilobular involvement, and pattern of iodized oil uptake, tumor size reduction, and radiologic T classification on computed tomography scan performed 7 and 30 days after TACE. However, only ascites, alpha-fetoprotein (>400 U/L), tumor size (>50%), Child-Pugh grade (Child C), pattern of iodized oil uptake, and portal vein thrombosis were independent factors in multivariate analysis. Using the beta-coefficients of alpha-fetoprotein (>400 U/L), tumor size (>50%) and Child-Pugh score, a prognostic index was calculated, and according to this index patients were classified into 3 categories with different prognoses. Ascites was excluded from the analysis because it is included in Child-Pugh grade, and iodized oil uptake was excluded because it cannot be evaluated before treatment.

CONCLUSIONS

This simple prognostic index can predict the survival of patients treated with TACE and can therefore be used to decide which patients with unresectable HCC should receive this therapy. TACE should not be administered to patients with one or more positive prognostic factors.

Downstream sequence adjacent to AUG affects translation of chloramphenicol acetyl transferase in eukaryotic cells

The CAT gene is widely used as a reporter in eukaryotic systems because of the efficient translation of its mRNA. We report here that a sequence occurring in the CAT mRNA at +15 nucleotides from CAT AUG is essential for translation. This sequence includes a stem-loop structure, which, however, exhibits a calculated stability significantly lower than that required for a hairpin to act as an enhancer of translation in vitro. Replacement of this region with the corresponding sequence from mRNAs that are normally translated in eukaryotic systems drastically reduced translation of CAT in COS cells, although the consensus sequence around the AUG, known to be required for high-level translation initiation, was conserved. These observations may be relevant for the exploitation of the CAT reporter system for analysis of the mechanisms of translation initiation by means of fusion constructs.

Circulating antibodies against the breast tumor marker GCDFP-15/gp17 in mammary carcinoma patients and in patients carrying benign breast conditions

Sera samples from 111 women, including 73 breast cancer patients and 38 patients with benign diseases of the breast, were examined. These were compared with samples from healthy women or from patients carrying tumors of origin other than breast as controls. This was done to determine whether antibodies against GCDFP-15/gp17, a protein of gross cystic disease fluid also secreted by mammary apocrine tumor cells, could be found. We observed that 2.6% of mammary disease patients affected by benign conditions and 5.5% of patients carrying malignant mammary gland tumors expressed statistically significant amounts of antibodies against GCDFP-15/gp17 (p < 0.01). The highest circulating anti-GCDFP-15/gp17 antibody levels occurred in patients with highly malignant ductal or lobular carcinoma of the breast and in patients with dysplasia. No correlation was found between the presence of circulating antibodies and the size of the tumor or the age of the patients. A bimodal correlation with the percent of invaded lymph nodes was observed instead. IgM and IgG isotypes were detected among the circulating anti-GCDFP-15/gp17 antibodies, suggesting the involvement of a T-cell-mediated immunoresponse. Our findings raise the possibility that the anti-GCDFP-15/gp17 immune response may be useful as a tool for investigating some aspects of the mechanisms of breast disease progression and that GCDFP-15/gp17 may be explored as an antigen for anti-tumor vaccination. Int. J. Cancer (Pred. Oncol.) 84:568-572, 1999.

Influence of the vitamin D receptor gene polymorphism on bone loss in men after liver transplantation

BACKGROUND

Bone loss is a frequent complication after liver transplantation.

OBJECTIVE

To investigate whether vitamin D receptor gene polymorphism influences bone loss in men after liver transplantation.

DESIGN

Prospective cohort study.

SETTING

University hospital.

PATIENTS

55 male candidates for liver transplantation.

MEASUREMENTS

Lumbar spine bone mineral density was measured before and 3, 6, 12, and 24 months after liver transplantation. Vitamin D receptor genotype was determined by restriction endonuclease Bsml.

RESULTS

Vitamin D receptor genotypes were significantly associated with post-transplantation changes in bone mineral density (P = 0.028). Within 3 months after transplantation, patients with the genotypes Bb or BB showed a vertebral bone loss substantially greater than that in patients with the bb genotype (between-group difference in the percentage change with respect to baseline bone mineral density, 3.7% [95% CI, 0.6% to 6.9%1). In 3 to 24 months after transplantation, bone mineral density increased steadily in the three allelic groups.

CONCLUSIONS

Vitamin D receptor gene polymorphism influences bone loss after liver transplantation. Patients with the bb genotype are, to some extent, protected against post-transplantation bone loss.

Biosynthesis and immunobiochemical characterization of gp17/GCDFP-15. A glycoprotein from seminal vesicles and from breast tumors, in HeLa cells and in Pichia pastoris yeast

The gp17 factor is a secretory product of human seminal vesicle cells which binds to CD4 and acts as a potent inhibitor of T lymphocyte apoptosis induced by CD4 crosslinking and subsequent T-cell receptor (TCR) activation. The protein is identical to gross cystic disease fluid protein-15 (GCDFP-15), a breast tumor secretory marker PIP (prolactin inducible protein), a prolactin-controlled and androgen-controlled protein; secretory actin binding protein (SABP), a seminal plasma actin binding protein and extra-parotid glycoprotein (EP-GP), a secretory protein from the salivary gland. The structure of this protein has not yet been elucidated and no biological function has been clearly attributed to date. Expression of recombinant gp17/GCDFP-15 cDNA in bacteria and insect cells leads to the production of a misfolded insoluble protein. In this study, we describe the production of gp17/GCDFP-15 in two different eukaryotic systems, namely HeLa cells and the Pichia pastoris yeast. Using constructs in which gp17/GCDFP-15 was tagged with enhanced green fluorescent protein (EGFP) in various combinations, we observed expression only when the fusion protein was directed to the secretory compartment by the correct signal peptide. The resulting fluorescent protein was inefficiently secreted, thus suggesting that gp17/GCDFP-15 is not appropriately post-translationally processed and/or transported in HeLa cells. The use of the P. pastoris secretory pathway allowed instead the accumulation in the culture medium of a GCDFP-15/gp17 species which retained the ability to bind to CD4 and also most of the biochemical and immunological properties of the native protein. The production of an active recombinant molecule opens the way to correlate the structural properties of this peculiar factor to its ability to bind several proteins, including CD4, and to block CD4-mediated T cell programmed death.