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Antinuclear antibodies (ANA) are prescribed as first-line autoantibodies in suspicion of mainly systemic autoimmune diseases. They include antibodies recognizing antigenic structures localized in the nucleus of cells, but also in the cytoplasm, at the membranes or transitional structures related to the cell cycle. Their research is based on screening and identification tests. For these tests, there is little or no standardization and harmonization of professional practices is necessary. From a questionnaire sent to healthcare professionals involved in the realization and interpretation of tests of autoimmunity, an overwiew of routine practices for the research of the ANA and their identification, was directed by the EASI Group International. Here, we present the results of the survey carried out in France. The analysis of these results faced with that of other countries as well as international recommendations allowed us to propose a synthesis of the main recommendations adapted to the regulatory texts of the NABM in France. These recommendations are addressed to those who prescribe, to those who perform biological analysis and to clinicians and biologists who interpret the results. They allow better understanding and admitting the methodological differences and their evolutions, to encourage the choice of the best technique based on the clinical context, to inform the clinician of the characteristics of the tests used.

Objective Celiac disease is a complex autoimmune disease affecting patients of any age, who may present a wide variety of clinical manifestations. Different guidelines for the diagnosis and management of celiac disease have been recently published. The aim of this study was to determine whether the recommendations issued in these guidelines have been adopted by physicians in France when celiac disease was suspected. Methods A total of 5521 physicians were asked to fill in a detailed questionnaire on diagnosing celiac disease to evaluate their medical practice, as to the type of symptoms leading to the suspicion of celiac disease, the prescription of duodenal biopsy or serological tests, the type of serological tests (anti-tissue transglutaminase, anti-endomysium, anti-gliadin and anti-reticulin antibodies, total immunoglobulin A measurement) prescribed to diagnose celiac disease. Results The analysis of the responses of 256 general practitioners (GPs), 221 gastroenterologists and 227 pediatricians showed that the protean clinical presentations of celiac disease might be better recognized by gastroenterologists and pediatricians than by GPs. Gastroenterologists asked for duodenal biopsy much more often than GPs and pediatricians when celiac disease was suspected. Serological testing and knowledge of critical markers, prescribed to diagnose celiac disease, differed among GPs, gastroenterologists and pediatricians. Conclusion Analysis of medical prescriptions showed that the recommendations for celiac disease diagnosis are not necessarily followed by physicians, emphasizing the fact that the impact of national or international guidelines on medical behavior should be evaluated.

Joint Bone Spine - In Press.Proof corrected by the author Available online since samedi 24 janvier 2015

Resume Depuis quelques annees, les techniques de multiplexage se repandent dans les laboratoires de biologie medicale, en particulier dans le domaine de la serologie auto-immune. Ces nouveaux procedes analytiques permettent la detection simultanee de plusieurs autoanticorps, permettant une meilleure productivite et incitant a definir des profils d'autoanticorps adaptes au diagnostic et au suivi des principales maladies auto-immunes. Qu'ils reposent sur le principe de l'immunodot, de la technologie Luminex ® ou des puces a antigenes, ces procedes ont chacun leurs avantages et leurs limites qu'il convient de bien peser pour determiner leur choix. Les immunodots, utilises depuis le plus longtemps, sont bien adaptes a la realisation d'analyses ponctuelles ou en petites series. D'introduction plus recente, les systemes utilisant la technologie Luminex ® permettent de traiter de facon automatisee la plus grande partie de la serologie auto-immune et de rendre des resultats quantitatifs. Les puces a antigenes permettent d'identifier et de quantifier de tres larges panels d'analytes. Cantonnees jusqu'a present dans des laboratoires de recherche, elles devraient deboucher prochainement sur des systemes adaptes a la detection d'autoanticorps en routine.

Our objective was to evaluate the prevalence of autoantibodies to cyclic citrullinated peptides (anti-CCP aAbs) in a cohort of patients with a variety of inflammatory or non-inflammatory rheumatic diseases other than rheumatoid arthritis (RA). Six hundred and nine serum samples were tested for anti-CCP aAbs and for rheumatoid factor (RF) using enzyme-linked immunosorbent assays and immunonephelometry. The prevalence of anti-CCP aAbs and RF reached 10% and 25%, respectively, using the positive cutoff value suggested by the manufacturers. Using a higher cutoff value (50 U/ml) for both aAbs, the prevalence was lower with 6% and 16%, respectively. The specificity of both markers for RA thus reached 94% and 84%, respectively. Anti-CCP aAbs were found to be elevated in inflammatory and also in non-inflammatory rheumatic diseases in the same proportion. Clinical data obtained for 36 positive patients showed that 17% developed RA within 5 years. In conclusion, anti-CCP aAbs are clearly more specific than RF for RA. Follow-up of anti-CCP aAbs-positive patients with inflammatory or non-inflammatory rheumatic diseases other than RA could be important considering the predictive value of these aAbs for the development of RA.

The usefulness of immumoglobulin (Ig) A antibodies to gliadin (AGA-IgA) in addition to IgA anti-endomysium and tissue transglutaminase antibodies was evaluated in 4122 children younger than 2 years with a suspicion of coeliac disease (CD). Eight percent (312/4122) displayed IgA anti-endomysium and/or IgA anti-tissue transglutaminase, whereas 2.1% (85/4122) displayed only AGA-IgA. Clinical data were obtained for 62 of 85 children with isolated AGA-IgA, and 33 children underwent a duodenal biopsy. Histologically proven CD was established for 5 patients, whereas 57 children were diagnosed to experience other diseases. The systematic detection of AGA-IgA using native gliadin conferred no additional diagnostic benefit for the diagnosis of CD in children younger than 2 years of age, except for rare cases.

Celiac disease is a complex autoimmune disease affecting patients of any age, who may present a wide variety of clinical manifestations. Different guidelines for the diagnosis and management of celiac disease have been recently published. The aim of this study was to determine whether the recommendations issued in these guidelines have been adopted by physicians in France when celiac disease was suspected.A total of 5521 physicians were asked to fill in a detailed questionnaire on diagnosing celiac disease to evaluate their medical practice, as to the type of symptoms leading to the suspicion of celiac disease, the prescription of duodenal biopsy or serological tests, the type of serological tests (anti-tissue transglutaminase, anti-endomysium, anti-gliadin and anti-reticulin antibodies, total immunoglobulin A measurement) prescribed to diagnose celiac disease.The analysis of the responses of 256 general practitioners (GPs), 221 gastroenterologists and 227 pediatricians showed that the protean clinical presentations of celiac disease might be better recognized by gastroenterologists and pediatricians than by GPs. Gastroenterologists asked for duodenal biopsy much more often than GPs and pediatricians when celiac disease was suspected. Serological testing and knowledge of critical markers, prescribed to diagnose celiac disease, differed among GPs, gastroenterologists and pediatricians.Analysis of medical prescriptions showed that the recommendations for celiac disease diagnosis are not necessarily followed by physicians, emphasizing the fact that the impact of national or international guidelines on medical behavior should be evaluated.

Resume Afin d'evaluer l'interet d'un nouveau substrat pour la detection des anticorps anti-nucleaires (AAN) par immunofluorescence indirecte, les cellules HEp-2000®, une etude multicentrique impliquant 19 laboratoires et 1 253 serums a ete realisee. Chaque laboratoire a analyse environ 40 serums temoins de sa propre serotheque (10 negatifs et 30 positifs correspondant aux principaux types de fluorescence) et 30 serums « tout-venant a. Chaque serum a ete teste en parallele, a la dilution de 1 80 , sur HEp-2000® et sur le substrat habituel du laboratoire. Pour les differents types de fluorescence, la concordance des resultats obtenus sur les deux substrats etait globalement de 93 % (de 83 a 100 % selon le laboratoire). Pour 17 serums, les cellules HEp-2000® ont permis de mettre en evidence des anticorps anti-SSA qui n'avaient pas ete deceles sur le substrat de routine ; a l'inverse, un seul serum a paru negatif sur HEp-2000® alors que des anticorps anti-SSA ont ete mis en evidence sur le substrat habituel du laboratoire. En conclusion, les cellules HEp-2000® permettent de detecter les anticorps anti-SSA avec une plus forte sensibilite que les substrats classiques, tout en fournissant pour les autres AAN des resultats tres similaires.

Pendant longtemps les analyses d’auto-immunite ont ete realisees de facon manuelle, en utilisant des techniques parfois artisanales. Plusieurs facteurs conduisent aujourd’hui les laboratoires a automatiser ces examens.

International audience; OBJECTIVE: Giant cell arteritis (GCA) is the most frequently occurring vasculitis in elderly individuals, and its pathogenesis is not fully understood. The objective of this study was to decipher the role of the major CD4+ T cell subsets in GCA and its rheumatologic form, polymyalgia rheumatica (PMR). METHODS: A prospective study of the phenotype and the function of major CD4+ T cell subsets (Th1, Th17, and Treg cells) was performed in 34 untreated patients with GCA or PMR, in comparison with 31 healthy control subjects and with the 27 treated patients who remained after the 7 others withdrew. RESULTS: Compared with control subjects, patients with GCA and patients with PMR had a decreased frequency of Treg cells and Th1 cells, whereas the percentage of Th17 cells was significantly increased. Furthermore, an analysis of temporal artery biopsy specimens obtained from patients affected by GCA for whom biopsy results were positive demonstrated massive infiltration by Th17 and Th1 lymphocytes without any Treg cells. After glucocorticoid treatment, the percentages of circulating Th1 and Th17 cells decreased, whereas no change in the Treg cell frequency was observed. The frequency of CD161+CD4+ T cells, which are considered to be Th17 cell precursors, was similar in patients and control subjects. However, these cells highly infiltrated GCA temporal artery biopsy specimens, and their ability to produce interleukin-17 in vitro was significantly enhanced in patients with GCA and patients with PMR and was correlated with a decrease in the phosphorylated form of STAT-1. CONCLUSION: This study is the first to demonstrate that the frequency of Treg cells is decreased in patients with GCA and patients with PMR, and that CD161+CD4+ T lymphocytes, differentiated into Th1 cells and Th17 cells, are involved in the pathogenesis of GCA and PMR.

Le developpement de la serologie auto-immune a rendu necessaire d’automatiser les analyses. L’adaptation de techniques ELISA sur des automates pour microplaques n’est pas exempte de difficultes. La technologie “multiplex” commercialisee par la firme Luminex rend possible la recherche simultanee de plusieurs autoanticorps dans un meme echantillon biologique. Cette technologie repose sur des microbilles en polystyrene contenant des quantites determinees de deux colorants fluorescents.

The clinical phenotype and evolution of antisynthetase syndrome (ASS) are heterogeneous. This study was therefore undertaken to identify subgroups of ASS patients with similar clinico-biological features and outcomes. This retrospective multicentric study included 233 consecutive patients with three different anti-aminoacyl-tRNA-synthetase antibodies (anti-ARS): anti-Jo1 (n=160), anti-PL7 (n=25) and anti-PL12 (n=48). To characterise ASS patients, bivariate, multiple correspondence (MCA), cluster and survival analyses were performed. Interstitial lung disease (ILD) and myositis were the most common ASS manifestations. However, their respective frequencies were correlated to anti-ARS specificity: ILD was more frequent (80% and 88% vs 67%, p=0.014) whereas myositis was less common (44% and 47% vs 74%, p

A monoclonal antibody, F11C, was raised against rat colon cancer cells. Its immunoreactivity on normal human and rat gut as well as human and rat colonic tumours was studied by the avidin-biotin-peroxidase complex technique. In both normal rat and human gastrointestinal tract, F11C stained surface epithelial cells from the fundus to distal colon, mainly as supranuclear vesicles. These vesicles appeared to be part of the Golgi apparatus on electron microscopy with immunogold labelling. Twenty primary rat colon tumours and 28 of 43 human colon tumours were also stained, with a heterogeneous pattern but much more strongly than the normal colonic mucosa. Biochemical purification suggested that in rat tumours F11C epitope was carried by a high molecular weight glycoprotein. Absorption experiments with synthetic oligosaccharides showed that F11C monoclonal antibody reacted with blood group A-related oligosaccharides. Nevertheless, F11C reactivity on human tissues was not related to the individual ABO or Lewis phenotype.

Two tumor cell variants (PROb and REGb) isolated from a single chemically-induced rat colon adenocarcinoma were previously shown to differ in their tumorigenicity. When injected into syngeneic BDIX rats, PROb cells induce progressive tumors whereas REGb cells give rise to tumors which always regress. PROb and REGb variants also differ in their capacity to induce an immune response in the syngeneic host. Regression of REGb tumors could have been mediated by cytotoxic effector cells acting at the tumor site. To test this hypothesis, the cytolytic activity of non-adherent lymphoid cells isolated from PROb and REGb tumors and from the spleen of the same animals were compared. The same number of infiltrating lymphocytes was recovered per gram of PROb or REGb tumor. The cytolytic activity of tumor infiltrating lymphocytes, as that of spleen lymphocytes, was predominantly non specific, as demonstrated by their ability to kill YAC-1 cells, an NK-sensitive cell line. PROb cells were relatively resistant to the cytotoxic activity of spleen or tumor infiltrating lymphocytes. In the regressing REGb tumors, the cytotoxic activity of tumor infiltrating lymphocytes to homologous cells or to YAC-1 cells was low and significantly inferior to that of the corresponding spleen lymphocytes. These results suggest that the cytotoxic activity of lymphocytes was impaired at the local, intratumoral level, even in spontaneously regressing tumors.

Candidemia is a life-threatening infection in the ICU whose prognosis is highly dependent on the stage at which it is recognized. Procalcitonin (PCT) levels have been shown to accurately distinguish between bacteremia and noninfectious inflammatory states in critically ill patients with clinical signs of sepsis. Little is known about the accuracy of PCT for the diagnosis of candidemia in this setting. A medical intensive care unit in a teaching hospital. Review of the medical records of every non-neutropenic patient with either bacteremia or candidemia and clinical sepsis in whom PCT dosage at the onset of infection was available between May 2004 and December 2005. Fifty episodes of either bacteremia (n = 35) or candidemia (n = 15) were included. PCT levels were found to be markedly higher in patients with bacteremia than in those with candidemia. Moreover, a low PCT value was found to be an independent predictor of candidemia in the study population. According to the calculation of the area under the receiver operating characteristic curve, PCT was found to be accurate in distinguishing between candidemia and bacteremia (0.96 [0.03]). A PCT level of higher than 5.5 ng/ml yields a 100% negative predictive value and a 65.2% positive predictive value for candidemia-related sepsis. A high PCT value in a critically ill non-neutropenic patient with clinical sepsis is unlikely in the setting of candidemia.

Plusieurs types d’autoanticorps peuvent etre mis en evidence dans le serum des patients atteints de polyarthrite rhumatoide (PR). Le plus connu et le plus utilise est le facteur rhumatoide (FR) qui constitue encore un des sept criteres de classification de la PR de l’American College of Rheumatology. Cependant, si les FR sont des marqueurs sensibles, ils ne sont pas totalement specifiques de la PR. En revanche, les anticorps anti-proteines ou peptides citrulline(e)s sont recemment apparus comme ayant une bonne sensibilite et surtout une specificite tres elevee vis-a-vis de la PR. Ils permettent d’en poser le diagnostic de facon tres precoce et de predire les formes les plus agressives de la maladie qui necessitent une prise en charge adaptee.

The systemic changes induced by inflammation have been referred as the acute-phase response. The changes in the concentrations of acute-phase proteins are due largely to changes in their production by hepatocytes induced by pro-inflammatory cytokines. Because of its specificity, sensibility and short half-life, C-reactive protein is the most useful indicator among all the acute-phase proteins. The clinical strategy to deal with an acute-phase response is to search the aetiology: infections, neoplasms, auto-immune and allergic diseases. The treatment of an acute-phase response is the treatment of its aetiology.

NKR-P1 has been identified as a triggering structure selectively expressed on rat natural killer (NK) cells and adherent lymphokine-activated killer (A-LAK) cells. In vivo treatment with anti-NKR-P1 monoclonal antibody (mAb 3.2.3) was shown to induce complete inhibition of NK cytotoxicity and elimination of LAK cell precursors in Lewis and Fisher rat strains. We investigated the effects of mAb 3.2.3 in a colon tumor model in BDIX rats. Inoculation of animals with mAb 3.2.3 even at very high doses induced a strong but incomplete inhibition of NK cytotoxicity in nylon-wool-non-adherent spleen and peripheral blood cells. Generation of adherent A-LAK cells from their spleen precursors was also strongly by not fully inhibited. We also investigated the effect of treatment with mAb 3.2.3 on the tumorigenicity of the NK-sensitive REGb cell line. When subcutaneously inoculated in syngeneic animals, REGb cells induce tumors that first grow for 2 weeks, then spontaneously regress and disappear. In contrast with previous results using anti-asialoGM1, no significant difference in tumor growth was observed between rats treated with mAB 3.2.3 and control animals, even with a long-term treatment. In vitro, mAb 3.2.3 exhibited the same incomplete efficiency. Nylon-wool-non-adherent spleen cells treated with mAb 3.2.3 plus complement were completely free of 3.2.3(bright) cells, but retained a substantial NK activity and generated LAK cells after culture with IL-2. After an overnight incubation in standard medium of 3.2.3-depleted spleen cells, 3.2.3(bright) cells were partially recovered and the NK cytotoxic activity, as well as the generation of LAK cells, was significantly enhanced. These results suggest that a strong expression of NKR-P1 is not required for BDIX mononuclear cells to exhibit NK function and generate LAK cells under IL-2 activation.

Previous reports demonstrated that progressor and regressor tumor-cell variants isolated from the same colon carcinoma chemically induced in a BD-IX rat differed in their capacity to induce an immune response. The present study was aimed at analyzing the characteristics of the responses to the regressor REGb and progressor PROb clones. Spleen cells from rats bearing early REGb tumors neutralized PROb cell tumorigenicity in a Winn-type local transfer assay, but responded occasionally to REGb and PROb cells in vitro. However, spleen cells from rats immunized by several injections of REGb and PROb cells strongly proliferated when cultured with PROb or REGb cells. This response was selective for the cell lines generated from the individual tumor at the origin of PROb and REGb lines, was dependent on CD4+ spleen cells, and was partially inhibited by an antibody against major histocompatibility complex class-II molecules. Although PROb cells shared tumor-rejection antigen(s) with REGb cells, splenocytes from PROb tumor-bearing rats did not neutralize PROb-cell tumorigenicity in vivo, nor did they proliferate when cultured with PROb or REGb cells in vitro. The unresponsiveness of spleen cells from PROb tumor-bearing rats was not due to the presence of immune suppressive cells, and a defect of antigen-presenting cells was shown to be unlikely. This unresponsiveness was limited to a lymphocyte subpopulation, since spleen cells from tumor-bearing rats responded normally to stimulation by PHA or allogeneic lymphocytes. These results strongly suggest that unresponsiveness of spleen cells from tumor-bearing rats is due to a tumor-specific anergy of the lymphocyte clones able to respond to tumor-associated antigens.

We have tried to develop a new model consisting of rats transplanted with syngeneic colon carcinoma PROb cells transfected with cDNA coding for the carcinoembryonic antigen (CEA), the human tumor marker most commonly used as target for MAbs. The antigenic density of the 4 CEA-expressing clones selected for a precise characterization ranged from 5 × 104 to 1 × 106 CEA molecules per cell. In all clones the CEA was shown to be attached to the membrane by a phosphatidylinositol (PI) anchor. Using a panel of radiolabeled MAbs directed against the 5 major epitopes described on the CEA molecule, we showed that all these CEA epitopes were expressed by the 4 transfectants. Southern-blot analysis showed that the entire CEA cDNA was present in the transfectants. Western-blot analysis, however, showed that the size of the CEA expressed by the 4 transfectants was slightly smaller than that of CEA produced by 2 reference human colon-carcinoma cell lines. Two clones, expressing 1 × 105 and 1 × 106 CEA molecules per cell, respectively, were grafted s.c. in nude mice and rats. Injection of radiolabeled anti-CEA F(ab')2 fragments into these animals showed specific tumor localization with the highest percentages of injected doses for the transfectants expressing the highest CEA level. When grafted into immunocompetent syngeneic BDIX rats, the CEA-expressing clones induced a strong antibody response against CEA and tumor rejections in a majority of the animals. Although the analysis of the immune response against the CEA-cDNA-transfected carcinoma cells is under investigation, the present results demonstrate that human CEA could function as a rejection antigen when transfected into rat carcinoma cells. © 1992 Wiley-Liss, Inc.

Cell variants that differ in their tumorigenicity and immunogenicity have been isolated from a BDIX rat colon adenocarcinoma cell line, DHD/K12. One variant, PRO, and the clones derived from it, are poorly immunogenic and induce progressive and metastatic tumors; the other one, REG, and its clones, are highly immunogenic and induce regressive tumors. When looking for a membrane marker distinguishing between PRO and REG lines, we obtained monoclonal hybridomas by immunizing BALB/c mice with PROb or REGb cell clones. Hybridoma F11C, producing an IgM monoclonal antibody (MAb) was able to distinguish between the cell variants on membrane immunofluorescence. All REGb cells strongly express F11C membrane antigen. On PROb cells, F11C antigen expression is weak, as demonstrated by cytofluorimetric analysis, and limited to a fraction of the cell population. The F11C membrane antigen is highly specific for the DHD/K12 cell line and the variants derived from it, but is not expressed on cells dissociated from the DHD transplanted tumor, from which DHD/K12 was established, suggesting that F11C antigen emerged during cell culture. Fluorescence absorption on synthetic oligosaccharides demonstrated that F11C antibody cross-reacts with A type 3, A type 4 and A type 5 chain blood group tetrasaccharides.

Macrophage biological responses to endotoxins have been extensively studied; nevertheless, the mechanisms by which endotoxins activate macrophage tumoricidal activity are not currently understood. We used liposomes to investigate the interaction of endotoxins with macrophages. In a medium containing 10 μg endotoxin/ml, macrophage-mediated cytolysis ranged from −7 to 36%. In all the experiments, 1 mM dipalmitoyl phosphatidyl choline (DPPC) small unilamellar liposomes significantly induced or enhanced cytolysis, ranging from 30-90%. Liposomes and endotoxins had a synergistic effect on the macrophage cytolytic activity. This effect was dose-dependent on liposome concentration, ranging from 0.25–1 mM or 2 mM. Liposomes decreased the endotoxin concentration threshold necessary to induce cytolysis. They did not modify the kinetics of macrophage activation. Liposomes did not modify the binding of tumor cells to macrophages. The optimum synergistic effect was obtained when liposomes were present during the first 18 h of the mixed culture of macrophages and target cells, before adding endotoxins for the next 18 h. When cholesterol was added to DPPC (M/M), liposomes did not enhance but rather inhibited macrophage activation by endotoxins.

Fluorescence microscopy and high pressure liquid chromatography were used to study the decrease of doxorubicin (DXR) concentrations in the liver, spleen, heart, lung, kidney and skeletal muscle of two strains of rats at various times after a single intravenous injection of the drug (8 mg kg−1). DXR was located within the cell nucleus and was mostly undegraded, it persisted, especially in heart, lungs and spleen where it was detectable 10 days after injection. The DXR/DNA ratio, was used as an index of nuclear fixation of the drug. A major difference in the DXR/DNA ratio between the two strains were observed in heart and spleen results; the DXR/DNA ratio was significantly higher in heart and spleen compared with lung, liver and kidney in both strains.

The effect of a high dietary level of polyunsaturated fat was tested on the growth of three different colon cancer cell lines injected subcutaneously into syngeneic rats. This effect was also tested on the in vitro cytolytic activity of resident peritoneal macrophages, natural or endotoxin and/or indomethacin-modulated. A 12% corn oil dietary supplement had no effect in any of the cases tested.

In a previous work, a cell line (DHD/K12) was established from a colon adenocarcinoma induced in a BDIX rat by 1,2-dimethylhydrazine. From this line, two cloned sublines, PROb and REGb, were then isolated. When subcutaneously inoculated into syngeneic rats, PROb cells yield progressive tumors, whereas REGb cells yield tumors which regress. In this study, in a 16-h 51Cr release assay, natural cytotoxicity mediated by BDIX splenic nonadherent lymphoid cells (NK cells) was shown to be much higher against REGb cells than against PROb cells. Whatever the target cells, NK cytotoxicity was always higher when the effector cells were obtained from males rather than from females. Treatment of BDIX splenic lymphocytes by anti-asGM1 serum plus complement revealed that both anti-asGM1 sensitive and non-sensitive NK cells exist. The activity of anti-asGM1 non-sensitive NK cells appeared to be minor and to be detected only when the level of cytotoxicity before treatment was sufficiently high. The difference between PROb and REGb tumor growth appears to be linked, at least in part, to a higher sensitivity of REGb cells to NK cells and especially to anti-asGM1-sensitive NK cells.

DHD/K12 TRb (PROb) and DHD/K12 TSb (REGb) are two cancer cell variants originating from the same rat colon adenocarcinoma. They differ in their tumorigenicity: when inoculated into syngeneic BDIX rats, PROb cells induce progressive tumors whereas REGb cells induce tumors which always regress. As previously described, there is an inverse relation between their tumorigenicity and their susceptibility to NCMC mediated by syngeneic spleen or peripheral blood lymphocytes: PROb cells are significantly less sensitive to NCMC than REGb cells. This suggests a role for NCMC in the regression of REGb tumors. In this work the BDIX NCMC effector cells active in vitro against REGb cells were identified as NK cells according to four criteria: (1) efficacy in a 4-h 51Cr release assay, (2) sensitivity to anti-asGM1 antibody plus complement, (3) LGL morphology, and (4) ability to bind with the same affinity REGb and YAC-1 cells. In spleen, these NK cells were heterogeneous with respect to their asGM1 surface density and their morphology. PROb cells were not lysed by these NK cells in a short-term cytotoxicity assay, but only in a 16-h assay. It was shown that PROb and REGb cells were bound with the same affinity by NK cells, thus they certainly differ in their ability to resist to NK lytic mechanisms. This difference could play a role in the different tumorigenicity of the two variants.

The effect of rat serum versus fetal calf serum on the in vitro natural cytolytic activity of rat lymphocytes, macrophages and polymorphonuclear cells against syngeneic tumour cells was compared. The cytolysis level mediated by the three varieties of effector cells was lower when rat serum was used instead of fetal calf serum to supplement the culture medium. This could explain in part the discrepancies found between in vitro and in vivo studies.

A long-term experiment was performed to test the ability of chenodeoxycholic acid (CDCA) to induce intestinal tumors in the Syrian golden hamster. Animals were fed a CDCA-enriched diet up to 12 months, and 4 of them were sacrificed every 2 months. CDCA exhibited no carcinogenic activity. However, unexpected amyloid deposits were discovered in both treated and nontreated animals. Their incidence was significantly higher in treated (71%) than in nontreated (27%) hamsters. During CDCA administration, amyloidosis appeared as early as the second month of treatment. It involved the liver, spleen and kidneys in more than half of the animals. On the contrary, in control animals, amyloid deposits appeared later and were most frequently restricted to one organ. The intensity of the lesions also appeared to be greater in the treated group. No monoclonal components were found in either serum or urine of the amyloidotic hamsters. Such an amyloidosis-promoting effect of CDCA has never been reported.

The effects of vinblastine, colchicine, lidocaine, and cytochalasin B on tumor cell killing by BCG-activated macrophages were examined. These four drugs were selected for their action on membrane-associated cytoskeletal components, microtubules, and microfilaments. Colchicine and vinblastine, which block microtubular synthesis, inhibit macrophage-mediated tumor-cell cytotoxicity at a concentration of 10−6 M. Cytochalasin B, which disrupts microfilaments, enhances tumor cell lysis and stasis due to activated macrophages at a concentration of 10−7 M. Lidocaine, which may induce the disappearance of both microtubules and microfilaments, has the same inhibiting effect as vinblastine at a concentration of 5×10−7 M. Whereas vinblastine and lidocaine seem to act on the macrophage itself, cytochalasin B exerts its effect predominantly on the tumor cell. These results suggest that microtubules and microfilaments play a role in the destruction of tumor cells by activated macrophages.

Background The usefulness of procalcitonin (PCT) measurement in critically ill medical patients with suspected nosocomial infection is unclear. The aim of the study was to assess PCT value for the early diagnosis of bacterial nosocomial infection in selected critically ill patients. Methods An observational cohort study in a 15-bed intensive care unit was performed. Seventy patients with either proven (n = 47) or clinically suspected but not confirmed (n = 23) nosocomial infection were included. Procalcitonin measurements were obtained the day when the infection was suspected (D0) and at least one time within the 3 previous days (D-3 to D0). Patients with proven infection were compared to those without. The diagnostic value of PCT on D0 was determined through the construction of the corresponding receiver operating characteristic (ROC) curve. In addition, the predictive value of PCT variations preceding the clinical suspicion of infection was assessed. Results PCT on D0 was the best predictor of proven infection in this population of ICU patients with a clinical suspicion of infection (AUROCC = 0.80; 95% CI, 0.68–0.91). Thus, a cut-off value of 0.44 ng/mL provides sensitivity and specificity of 65.2% and 83.0%, respectively. Procalcitonin variation between D-1 and D0 was calculated in 45 patients and was also found to be predictive of nosocomial infection (AUROCC = 0.89; 95% CI, 0.79–0.98) with a 100% positive predictive value if the +0.26 ng/mL threshold value was applied. Comparable results were obtained when PCT variation between D-2 and D0, or D-3 and D0 were considered. In contrast, CRP elevation, leukocyte count and fever had a poor predictive value in our population. Conclusion PCT monitoring could be helpful in the early diagnosis of nosocomial infection in the ICU. Both absolute values and variations should be considered and evaluated in further studies.

Introduction Management of the early stage of sepsis is a critical issue. As part of it, infection control including appropriate antibiotic therapy administration should be prompt. However, microbiological findings, if any, are generally obtained late during the course of the disease. The potential interest of procalcitonin (PCT) as a way to assess the clinical efficacy of the empirical antibiotic therapy was addressed in the present study. Methods An observational cohort study including 180 patients with documented sepsis was conducted in our 15-bed medical intensive care unit (ICU). Procalcitonin measurement was obtained daily over a 4-day period following the onset of sepsis (day 1 (D1) to D4). The PCT time course was analyzed according to the appropriateness of the first-line empirical antibiotic therapy as well as according to the patient outcome. Results Appropriate first-line empirical antibiotic therapy (n = 135) was associated with a significantly greater decrease in PCT between D2 and D3 (ΔPCT D2–D3) (-3.9 (35.9) vs. +5.0 (29.7), respectively; P < 0.01). In addition, ΔPCT D2–D3 was found to be an independent predictor of first-line empirical antibiotic therapy appropriateness. In addition, a trend toward a greater rise in PCT between D1 and D2 was observed in patients with inappropriate antibiotics as compared with those with appropriate therapy (+5.2 (47.4) and +1.7 (35.0), respectively; P = 0.20). The D1 PCT level failed to predict outcome, but higher levels were measured in the nonsurvivors (n = 51) when compared with the survivors (n = 121) as early as D3 (40.8 (85.7) and 21.3 (41.0), respectively; P = 0.04). Moreover, PCT kinetics between D2 and D3 were also found to be significantly different, since a decrease ≥ 30% was expected in the survivors (log-rank test, P = 0.04), and was found to be an independent predictor of survival (odds ratio = 2.94; 95% confidence interval 1.22 to 7.09; P = 0.02). Conclusions In our study in an ICU, appropriateness of the empirical antibiotic therapy and the overall survival were associated with a greater decline in PCT between D2 and D3. Further studies are needed to assess the utility of the daily monitoring of PCT in addition to clinical evaluation during the early management of sepsis.