Three-dimensional structures reveal multiple ADP/ATP binding modes for a synthetic class of artificial proteins.

The creation of synthetic enzymes with predefined functions represents a major challenge in future synthetic biology applications. Here, we describe six structures of de novo proteins that have been determined using protein crystallography to address how simple enzymes perform catalysis. Three structures are of a protein, DX, selected for its stability and ability to tightly bind ATP. Despite the addition of ATP to the crystallization conditions, the presence of a bound but distorted ATP was found only under excess ATP conditions, with ADP being present under equimolar conditions or when crystallized for a prolonged period of time. A bound ADP cofactor was evident when Asp was substituted for Val at residue 65, but ATP in a linear configuration is present when Phe was substituted for Tyr at residue 43. These new structures complement previously determined structures of DX and the protein with the Phe 43 to Tyr substitution [Simmons, C. R., et al. (2009) ACS Chem. Biol. 4, 649-658] and together demonstrate the multiple ADP/ATP binding modes from which a model emerges in which the DX protein binds ATP in a configuration that represents a transitional state for the catalysis of ATP to ADP through a slow, metal-free reaction capable of multiple turnovers. This unusual observation suggests that design-free methods can be used to generate novel protein scaffolds that are tailor-made for catalysis.

Meta-analysis: evaluation of adjuvant therapy after curative liver resection for hepatocellular carcinoma.

AIM: To evaluate adjuvant modalities after curative resection for hepatocellular carcinoma using a meta-analysis of randomized and non-randomized controlled trials. METHODS: In a first step, a meta-analysis of randomized controlled trials was carried out. Sensitivity analyses after inclusion of non-randomized controlled trials were performed. Four therapeutic modalities were evaluated: pre-operative transarterial chemotherapy, post-operative transarterial chemotherapy, systemic chemotherapy and a combination of systemic and transarterial chemotherapy. RESULTS: Only post-operative transarterial chemotherapy improved survival significantly at 2 years [difference, 22.8%; confidence interval (CI), 8.6-36.9%; P = 0.002] and 3 years (difference, 27.6%; CI, 8.2-47.1%; P = 0.005), and decreased the probability of no recurrence at 1 year (difference, 28.8%; CI, 16.7-40.8%; P < 0.001), 2 years (difference, 27.6%; CI, 8.2-47.1%; P = 0.005) and 3 years (difference, 28%; CI, 8.2-47.9%; P = 0.006). In a sensitivity analysis after inclusion of non-randomized controlled trials, post-operative transarterial chemotherapy still improved survival at 1 year (difference, 9.6%; CI, 0.8-18.3%; P = 0.03), 2 years (difference, 13.5%; CI, 0.9-26%, P = 0.04) and 3 years (difference, 18%; CI, 7-28.9%; P < 0.001), and decreased the probability of no recurrence at 1 year (difference, 20.3%; CI, 7.7-33%; P = 0.002), 2 years (difference, 35%; CI, 21.4-46.3%; P < 0.001) and 3 years (difference, 34.5%; CI, 18.7-50.3%; P < 0.001). CONCLUSION: Post-operative transarterial chemotherapy improved survival and decreased the cumulative probability of no recurrence. New randomized controlled trials evaluating this modality are required.

Excessive alcohol consumption favours high risk polyp or colorectal cancer occurrence among patients with adenomas: a case control study.

BACKGROUND AND AIMS: Excessive alcohol consumption is a risk factor for developing colorectal adenomas. This study aimed to investigate the influence of excessive alcohol consumption on the occurrence of high risk polyps (adenoma > or = 10 mm, villous component, high grade dysplasia) or colorectal cancer among patients with at least one colonic adenoma. PATIENTS AND METHODS: Three groups of patients with at least one colorectal adenoma were included in a case control study: 401 heavy drinkers (group HD, mean daily alcohol intake 117 (SD 4) g/day for a mean duration of 22 (SD 0.6) years), aged 57 (0.5) years (78% men); 152 patients suffering from irritable bowel syndrome (IBS), aged 61 (0.9) years (57% male); and 108 patients with a family history (FH) of colorectal adenoma or cancer, aged 55 (1) years (64% male). Exclusion criteria were: anaemia, haematochezia, personal history of colorectal adenoma or cancer, and for groups HD and IBS a family history of colorectal adenoma and/or cancer. Relative risks were estimated by the odds ratio (OR) using a logistic regression model and were expressed with 95% confidence interval (CI). RESULTS: After age and sex adjustment, the likelihood of having an adenoma > or = 10 mm was higher in group HD than in the IBS group (OR 1.8, 95% CI (1.2-2.7)) and the likelihood of having high risk adenomas or cancer was higher in group HD compared with the IBS group (OR 1.6, 95% CI (1.2-2.1)) and the FH group although this was not significant (OR 1.6, 95% CI (0.97-2.6) (p=0.081); 90% CI (1.03-2.4)). After age and sex adjustment, the likelihood of having an adenoma with high grade dysplasia or cancer was higher in group HD than in the IBS group (OR 1.7, 95% CI (1.02-2.8)) or group FH, although this was not significant (OR 3.7, 95% CI (0.98-15) (p=0.076); 90% CI (1.10-12.47)). CONCLUSION: In patients with at least one colorectal adenoma, excessive alcohol consumption increases the likelihood of developing high risk adenomas or colorectal cancer.

[Ulceronecrotic tracheobronchial involvement in Crohn's disease]. / Atteinte trachéo-bronchique ulcéro-nécrotique au cours d'une maladie de Crohn.

We report the case of a young female patient hospitalized for the first episode of a colonic Crohn's disease with specific ulceronecrotic tracheobronchial involvement leading to chronic and invalidant cough. Symptomatic bronchopulmonary manifestations are very rare in the course of inflammatory bowel diseases and usually not mentioned in Gastroenterology textbooks.

Abnormal von Willebrand factor in bleeding angiodysplasias of the digestive tract.

BACKGROUND & AIMS: Involvement of an abnormal von Willebrand factor in the bleeding expression of gastrointestinal angiodysplasias has been suggested but not assessed by prospective studies. METHODS: To address this issue, 27 patients with either nonbleeding (group A, n = 9) or bleeding (group B, n = 9) digestive angiodysplasias or telangiectasias or diverticular hemorrhage (group C, n = 9) were enrolled. In all patients, an analysis of von Willebrand factor and a screening for the most common disorders associated with an acquired von Willebrand disease were performed. RESULTS: In all patients from groups A and C, von Willebrand factor was normal, and no underlying disease could be found. In contrast, all but 1 patient from group B had a variable selective loss of the largest multimeric forms of von Willebrand factor, associated in 7 cases with a stenosis of the aortic valve. CONCLUSIONS: This study indicates that most patients with bleeding angiodysplasia or telangiectasia have a deficiency of the largest multimers of von Willebrand factor induced by a latent acquired von Willebrand disease. Because these multimers are the most effective in promoting primary hemostasis at the very high shear conditions related to these vascular malformations, we suggest that their deficiency is likely to contribute to the bleeding diathesis.

[Regenerative nodular hyperplasia: variable clinical aspects]. / Hyperplasie nodulaire régénérative: des aspects cliniques très variables.

BACKGROUND: Regenerative nodular hyperplasia can take on very misleading aspects making diagnosis difficult. CASE REPORTS: We report three cases of regenerative nodular hyperplasia (RNH). In the first patient rupture of esophageal varices was associated with myelofibrosis. In the second, extensive portal thrombus formation was associated with consumption coagulopathy and essential thrombocytemia. The third patient had systemic sclerodermia, hepatic macronodules, refractory exsudative ascitis and chronic hepatic encephalopathy following surgery for a porto-cava anastomosis. DISCUSSION: The diagnosis of RNH should be suspected in a variety of clinical situations with search for associated diseases in all cases. The prognosis is related to the consequences of portal hypertension and the severity of the associated diseases.

Tumor necrosis factor soluble receptor p55 and lipid peroxidation in patients with acute alcoholic hepatitis.

OBJECTIVES: In experimental models, liver injury induced by ethanol, cytotoxic activity of tumor necrosis factor (TNF) -alpha is principally mediated by TNF receptor p55 (TNFRp55). Among the various mechanisms underlying the toxic effects of TNF-alpha, overproduction of reactive oxygen species seems to play a key role in mediating TNF-alpha-induced cytotoxicity. The aim of this study was to evaluate, in patients with alcoholic liver disease, whether alcohol TNFRp55-mediated hepatotoxicity could account for lipid peroxidation expressed by significant increase in serum thiobarbituric reactive acid substances (TBARS) content, and could be amplified by decrease in blood total glutathione content and decrease in plasma antioxidant protective capacity. METHODS: We studied 27 patients with histological alcoholic liver disease (five fibrosis, six acute alcoholic hepatitis (AAH) without cirrhosis, four cirrhosis without AAH, and 12 cirrhosis with AAH. TNFsRp55 and TNFsRp75 plasma levels were measured using ELISA assays. Plasma lipid peroxidation was evaluated by the content of TBARS. Total glutathione (tGSH) content in blood was determined by a kinetic assay. The sensitivity of erythrocytes to an oxidative stress and the plasma antioxidant protective capacity were simultaneously determined by a simple method. RESULTS: In the 18 patients with mild or severe AAH, the plasma levels of TNFsRp55 were negatively correlated with tGSH and were positively correlated with TBARS, with total bilirubin and with discriminant function. tGSH was positively correlated with plasma selenium. The plasma levels of TNFsRp75 were positively correlated with TBARS and with total bilirubin. There was no significant correlation with the mean inhibitory 50% plasma volume or with the percentage of hemolyzed erythrocytes. CONCLUSIONS: Our data support the notions that, in patients with AAH, TNFsRp55 probably mediates cytotoxicity of TNF-alpha, and that cytotoxic effect could be amplified by tGSH depletion in enhancing lipid peroxidation.

[Abdominal tuberculosis: deceptive and still encountered]. / La tuberculose abdominale: trompeuse et toujours d'actualité.

BACKGROUND: Extrapulmonary manifestations of tuberculosis are increasing in incidence. Abdominal tuberculosis may mimic a variety of gastrointestinal disorders. The diagnosis of abdominal tuberculosis is still difficult to establish before surgery. CASE REPORTS: We report 3 cases of abdominal tuberculosis in immunocompetent individuals. One patient presented with an ileocecal mass mimicking cancer. The second one presented with fever, ileocecal mass and ascites leading to the diagnosis of appendiceal peritonitis. The last patient was admitted for ascites, ovarian mass and high CA 125 serum level simulating ovarian cancer with peritoneal carcinomatosis. COMMENTS: In cases of abdominal tuberculosis when standard investigations are unhelpful, a PCR should be performed. Estimation of adenosine deaminase in ascitic fluid is an easy and reliable method for diagnosing tuberculous ascites. With these non invasive diagnostic procedures, surgery should be reserved only to patients with complications.

Detection of the fluorescence of GI vessels in rats using a CCD camera or a near-infrared video endoscope.

BACKGROUND: Choroidal near-infrared fluorescent angiography can detect vessels in the eye with high resolution. Observation of fluorescent gastrointestinal (GI) vessels by endoscopy may be useful in portal hypertension and bleeding ulcer. We here describe a technique for the detection of fluorescent GI vessels with a CCD camera or a near-infrared video endoscope. METHODS: Laparotomy was performed on rats. A tissue target was excited by means of a laser diode. We took pictures of tissue under both white and near-infrared light, both before and after intravenous injection of indocyanine green. Fluorescent light was selected by means of filters placed in front of the lens of a CCD camera or a near-infrared video endoscope. RESULTS: Under near-infrared light and after dye injection, we observed fluorescent vessels in real time and distinguished arterial from venous fluorescence. CONCLUSIONS: This device permits visualization of GI vessels, which could be useful for diagnosis of vascular abnormalities during endoscopy and surgery.

[Descriptive epidemiology of patients with alcoholic liver disease hospitalized in a hepato-gastroenterology service]. / Analyse descriptive des malades ayant une maladie alcoolique du foie hospitalisés dans un service d'Hépato-Gastroentérologie.

OBJECTIVE: To improve the detection of early stage alcoholic liver disease and to identify the importance of this disease, this study compared epidemiological characteristics, the reasons for and the duration of hospitalization, in-patient mortality and the frequency of multiple hospitalizations in alcoholic patients without cirrhosis and in patients with alcoholic cirrhosis hospitalized in the hepatogastroenterology department of Antoine-Beclere Hospital. MATERIAL AND METHODS: From January 1982 to December 1995, all patients with a daily alcohol intake in the previous year of at least 50 g per day and all patients with alcoholic cirrhosis whatever their drinking habits were studied. RESULTS: Three thousand three hundred and forty six patients were included. The daily alcohol intake in the previous five years was 118 +/- 81 g and the duration of alcohol abuse was 22 +/- 13 years. Two thousand one hundred eight patients had liver biopsy; 37% had histologically proven or probable cirrhosis. Forty one percent of the patients without cirrhosis who had liver biopsy already had steatofibrosis and/or acute alcoholic hepatitis. 32.5% of the patients had hepatitis B virus markers. 7.7% of the patients were positive for anti hepatitis C virus antibody. Thirty two percent of the patients with cirrhosis were women versus 22% of the patients without cirrhosis (P < 0.01). Alcoholism was the reason for the first hospitalization in sixty percent of the patients without cirrhosis and in twenty percent of the patients with cirrhosis (P < 0.01). On the other hand, ascites were the first reason for the first hospitalization in patients with cirrhosis (28%). The two main causes for multiple hospitalizations were also ascites and alcoholism. CONCLUSION: Two thirds of heavy drinkers did not have cirrhosis on admission since alcoholism was the first reason for multiple hospitalizations in these patients, therefore the management of alcoholism in out-patients must be improved.

[Biological diagnosis of the type of liver disease in alcoholic patients with abnormal liver function tests]. / Diagnostic biologique du type d'hépatopathie chez des malades alcooliques ayant des tests biologiques hépatiques anormaux.

OBJECTIVES: The histological diagnosis of the different stages of alcoholic liver disease is not systematic. The aim of this study was to assess whether common biological features were useful in identifying the different stages. METHODS: One thousand twenty six alcoholic patients with liver histology and without any associated diseases or infections likely to alter serum liver tests were studied. Diagnostic analyses were performed using stepwise discriminant analysis in the entire population and in asymptomatic patients. RESULTS: a) Serum ASAT activity levels were only normal in 39% of the patients with normal histological liver and in 14% of the patients with steatosis; b) liver failure was already present in patients with fibrosis without cirrhosis; c) betagamma block was the only biochemical parameter which confirmed the diagnosis of cirrhosis without biopsy; d) the diagnostic accuracy of common tests was weak for the diagnosis of alcoholic liver disease without cirrhosis but prothrombin time could be useful in excluding the diagnosis of cirrhosis with and without acute alcoholic hepatitis when liver biopsy is not available. CONCLUSION: Only a prothrombin time of 80% with a negative predictive value of 94% and the presence of beta-gamma [corrected] block with a positive predictive value of 98% were useful for assessing the diagnosis of cirrhosis in all patients with alcoholic liver disease.

A particularly aggressive combined glucagonoma and gastrinoma syndrome.

Duodeno-pancreatic biochemically polyfunctional endocrine tumour is a well known entity. Usually, only one hormone is responsible for the clinical features. We report a case of aggressive combined glucagonoma and gastrinoma tumour without metastases, causing respectively diabetic ketoacidosis and fulminant peptic ulcer, and death. Occasional patients can present with clinical features of both glucagonoma and gastrinoma. Diabetic patients exhibiting migratory skin lesions should be suspected of glucagonoma. In addition, a multidisciplinary approach to such patients including dermatologists, surgeons, radiologists and endoscopists is mandatory.

Plasma levels of soluble tumor necrosis factor receptors p55 and p75 in patients with alcoholic liver disease of increasing severity.

BACKGROUND/AIMS: Correlations between serum levels of soluble tumor necrosis factor receptors p55 (TNFsRp55) and Child Pugh index have previously been reported in alcoholic patients with cirrhosis. We have undertaken this study to improve understanding of the role of tumor necrosis factor soluble receptors (TNFsRs) in alcoholic liver disease. METHODS: One hundred and two patients with alcoholic liver disease of various severity (23 pure steatosis, 22 fibrosis, seven acute alcoholic hepatitis without cirrhosis, 12 cirrhosis without acute alcoholic hepatitis, 14 cirrhosis with mild acute alcoholic hepatitis and 24 cirrhosis with severe acute alcoholic hepatitis) were studied. Blood was collected on EDTA and plasma was tested for TNFsR concentrations using ELISA assays. RESULTS: Plasma levels of TNFsRp55 and p75 increased progressively with the severity of liver disease, reaching a maximum in cirrhotic patients with severe acute alcoholic hepatitis. Plasma levels of TNFsRp55 in patients with fibrosis and of TNFsRp75 in patients with acute alcoholic hepatitis without cirrhosis were already higher than in healthy controls. In cirrhotic patients with or without acute alcoholic hepatitis TNFsRp55 and p75 were significantly increased compared with controls. In cirrhotic patients, plasma levels of TNFsRp55 correlated positively with all parameters of liver injury, whereas the TNFsRp75/ TNFsRp55 ratio correlated negatively. In cirrhotic patients with severe acute alcoholic hepatitis, the TNFsRp75/TNFsRp55 ratio was significantly lower than in all other groups. In cirrhotic patients with severe acute alcoholic hepatitis treated by prednisolone, the decrease in TNFsRp55 plasma levels between day 1 and day 15 was significantly more important in patients still alive at 2 months than in patients who died within 2 months. CONCLUSIONS: These results show that the expression of TNF-soluble receptors (TNFsRs) participates in the early phases of the alcoholic liver disease and that the TNFsRp75/TNFsRp55 ratio and plasma levels of TNFsRp55 may help to determine the diagnosis and the prognosis of severe acute alcoholic hepatitis in cirrhotics.

Post-traumatic membranous obstruction of the inferior vena cava associated with a hypercoagulable state.

It has been hypothesized that abdominal trauma may be one of the factors involved in membranous obstruction of the inferior vena cava. We present two cases of membranous obstruction of the inferior vena cava associated with trauma. One asymptomatic case, associated with an occult myeloproliferative disorder, developed within 3 years of a violent abdominal trauma. The other case, associated with familial plasminogen deficiency, was discovered at surgery 3 days after a road accident with obvious abdominal trauma, since superimposed extensive thrombosis of the inferior vena cava caused acute Budd-Chiari syndrome. We conclude that underlying prothrombotic conditions are probably necessary for the development of membranous obstruction of the inferior vena cava and that minor trauma may contribute to the development of thrombosis through indirect mechanisms.

[Predictive risk factors for progression to cirrhosis in early stage alcoholic liver disease]. / Facteurs prédictifs d'évolution vers la cirrhose à un stade précoce de la maladie alcoolique du foie.

OBJECTIVE: To assess the risk factors of cirrhosis in early stage alcoholic liver disease. PATIENTS: We investigated 83 heavy drinkers (60 males and 23 females) in whom the first of two liver biopsies showed normal or pure alcoholic fatty liver. RESULTS: When the six following variables: sex, age, delay between the first and last biopsy, total duration of alcohol consumption before the first biopsy, daily alcohol consumption for the last 5 years before the first biopsy and the extent of fatty liver in the first biopsy, were considered together in stepwise regression analysis, the delay between the first and last biopsy (p < 0.0001), sex (P < 0.004) and the extent of fatty liver in the first biopsy (P < 0.06) significantly improved the prediction of cirrhosis. The odds ratio of cirrhosis for a women was 19.1 (confidence interval 95% [1.85-197]). The odds ratio for cirrhosis for a percentage of fatty liver > or = 5/10 was 7.4 (confidence interval 95% [1-92]). CONCLUSION: With the same delay between two liver biopsies, the female sex and the extent of fatty liver are two independent risk factors for the development of cirrhosis in heavy drinkers.

Interleukin-1 receptor antagonist plasma concentration is specifically increased by alpha-2A-interferon treatment.

BACKGROUND/AIMS: The mechanism of action of recombinant interferon-alpha (rIFN alpha) treatment in chronic hepatitis C is not fully understood, and may include modulation of the immune system as well as a direct antiviral effect. We have therefore evaluated the plasma concentrations of pro- and anti-inflammatory cytokines in patients with chronic hepatitis C before and during treatment with rIFN alpha. METHODS: Twenty-three patients were studied. Plasma concentrations of IL-1 beta, IL-6, TNF, IL-1 receptor antagonist (IL-1RA) and soluble TNF receptors (sTNFRs) type I and type II were determined twice before rIFN alpha treatment (on day -11 and day 1), and on days 11, 32 and 120 of treatment. RESULTS: IL-1 beta, IL-6 and TNF plasma concentrations were rarely increased before treatment (in one, six and seven patients, respectively), and usually declined during treatment. sTNFRs I and II plasma concentrations were not increased either before or during treatment. This was not the case for IL-1RA. In untreated patients, the plasma concentration of IL-1RA was higher than normal in 16 out of 23 patients. When rIFN alpha treatment was initiated, there was a constant and dramatic increase in IL-1RA levels, which reached 8 times the upper limit of the normal range (p < 0.001 as compared to pretreatment values). This increase was sustained up to day 120. CONCLUSIONS: These results indicate that induction of an anti-inflammatory status through modulation of the IL-1/IL-1RA balance may be a key mechanism of action of rIFN alpha treatment in chronic hepatitis C.

Survival and prognostic factors in patients with severe alcoholic hepatitis treated with prednisolone.

BACKGROUND & AIMS: Corticosteroids have been shown to significantly decrease short-term mortality in patients with severe alcoholic hepatitis. However, independent factors associated with a favorable outcome and long-term survival are unknown. The aim of this study was to examine prognostic factors and long-term survival in patients with biopsy-proven severe alcoholic hepatitis. METHODS: Of 183 patients studied, 61 had been randomized in a previous trial; 32 of them were treated with prednisolone (group I) and 29 were not treated (group II); 61 were treated from the end of this randomized trial (group III); and 61 were simulated (group IV). RESULTS: At 1 year, survival in group I (69%; confidence interval [CI], 57%-81%) and group III (71%; CI, 55%-87%) was better than in the nontreated groups (group II, 41%; CI, 23%-59%; P = 0.01) (group IV, 50%; CI, 37%-63%; P = 0.05). At 2 years, survival was not significantly different. Treated patients with marked liver polymorphonuclear infiltrate had better 1-year survival (76%; CI, 64%-88%) than the others (53%; CI, 35%-71%; P = 0.05). Treated patients with polymorphonuclear counts of > 5500/mm3 had better 1-year survival (77%; CI, 65%-89%) than the others (40%; CI, 14%-66%; P = 0.003). In the 93 treated patients, liver polymorphonuclear infiltrate (P < 0.03) and polymorphonuclear count (P < 0.001) were independently correlated with 1-year survival. CONCLUSIONS: Prednisolone reduced mortality by at least 1 year. Liver polymorphonuclear infiltrate and polymorphonuclear count were independent prognostic factors.

Prevalence of cholelithiasis according to alcoholic liver disease: a possible role of apolipoproteins AI and AII.

Moderate alcohol intakes decreases the risk of gallstones; in contrast, the prevalence of gallstones is increased in patients with alcoholic cirrhosis. The aims of this prospective study were to assess the prevalence of cholelithiasis among drinkers according to the histological severity of liver disease, and to estimate the importance of serum apolipoproteins AI and apolipoprotein AII as risk factors for gallstones. Among the 320 drinkers included, 53 patients had cholelithiasis. The prevalence increased (p < 0.0001) from 5% in patients with normal liver (1 of 22) and 6% in patients with steatosis only (3 of 47) to 13% in patients with fibrosis (7 of 54), reaching 27% among patients with biopsy-proven cirrhosis (28 of 103). Among patients with clinically obvious cirrhosis on whom biopsy was not performed mainly because of the severity of liver disease, the prevalence of cholelithiasis reached a maximum of 46% (6 of 13). Among drinkers with nonsevere liver disease, patients with cholelithiasis were older (59 +/- 9 years, mean +/- SD vs. 45 +/- 11, p = 0.003) with lower apolipoprotein AI (118 +/- 37 vs. 163 +/- 45 mg/dl; p = 0.002) and apolipoprotein AII (30 +/- 12 vs. 53 +/- 20 mg/dl; p = 0.0002) in comparison with patients without cholelithiasis. These differences persisted after considering by multiple logistic regression analysis, sex, and ideal body weight. Alcohol consumption during the last 5 years was lower in patients with cholelithiasis (83 g/day) in comparison with patients without cholelithiasis (142 g/day; p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

Weak immunogenicity of the preS2 sequence and lack of circumventing effect on the unresponsiveness to the hepatitis B virus vaccine.

The preS2 sequence is known to circumvent immunological unresponsiveness to the S protein and to induce a 'carrier' effect on the anti-S antibody production, in mice. In humans, an anti-S response was found in 100% and 97% of healthy subjects vaccinated with the S and S + preS2 preparations, respectively, whereas less than 50% of drinkers responded whatever the vaccine used. Anti-preS2 were found in 44% of healthy recipients of the S + preS2 vaccine, whereas there were no anti-preS2 responders in drinkers. Anti-preS2 remained undetectable in 32% of the blood donors hyperimmunized with the S + preS2 vaccine, whereas anti-S antibody boosted in all cases. In humans, in contrast to mice, immunogenicity of the preS2 sequence appears weak and the preS sequence does not circumvent the anti-S unresponsiveness.