Immunoglobulin heavy chain Diversity genes rearrangement pattern indicates that MALT-type gastric lymphoma B cells have undergone an antigen selection process

Gastric MALT lymphoma usually develops from chronic gastritis, the vast majority of which (>90%) is associated with Helicobacter pylori infection. We sequenced the third complementarity determining region (CDR3) of immunoglobulin heavy chain genes in 19 gastric MALT lymphoma clones to determine the pattern of variable (V), diversity (D) and joining (J) gene utilization during immunoglobulin gene rearrangement.
DNA was extracted from paraffin-embedded sections and the rearranged CDR3 regions were amplified using a semi-nested polymerase chain reaction (with primers complementary to the conserved framework-three segment of the variable region [FR3A] and J regions). The DNA used for cloning and sequencing was obtained after purification of monoclonal bands excised from polyacrylamide gels. The N-D-N region specific to each clone was compared with known germline D sequences.
Similarly to that observed in normal and leukaemic B cells, our series of gastric MALT lymphomas showed apparent preferential utilization of genes from the DXP family. In two cases no similarity between the CDR3 nucleotide sequences of the neoplastic clones and the known germline D sequences could be found. In 10/19 analysed alleles the lymphoma B-cell clones appeared to contain two D gene segments (D-D recombination), a rare occurrence in normal individuals but one which has been described as a significant event in the determination of idiotype expression and antigen-binding affinity. Remarkably, despite the use of different D and J segments, the resultant amino acid sequences matched in two patients, suggesting the presence of a common selecting antigen.
The observed pattern of D gene rearrangement suggests that MALT lymphoma B-cell clones have undergone antigen selection, which seems to indicate that the antigen stimulation plays a pivotal role in the development of the lymphoma.     

Relative Versus Absolute Carbohydrate-Deficient Transferrin as a Marker of Alcohol Consumption in Patients With Acute Alcoholic Hepatitis

BACKGROUND: Carbohydrate-deficient transferrin has been described as a sensitive and specific marker for alcohol consumption. This study investigated the usefulness of carbohydrate-deficient transferrin as a marker of alcohol consumption in acute alcoholic hepatitis. METHODS: Absolute concentrations (U/I) and relative values (%) of carbohydrate-deficient transferrin determined in serum with commercial assays, as well as conventional markers for alcohol consumption, were compared with the alcohol consumption (as estimated by a questionnaire) in patients with acute alcoholic hepatitis (n = 19), alcoholic liver cirrhosis (n = 37), and nonalcoholic liver diseases (n = 16). RESULTS: The concentration of carbohydrate-deficient transferrin was increased (p < 0.001) in nonabstaining patients (median intake 80 g alcohol/day) with alcoholic liver cirrhosis (45.7 +/- 30 U/l), but not in patients with acute alcoholic hepatitis (20.0 +/- 7.8 U/l) despite higher alcohol consumption (median 130 g/d), nor in abstainers with alcoholic liver cirrhosis (19.4 +/- 6.0 U/l) or nonalcoholic liver disease (18.5 +/- 6.7 U/l). However, the relative values of carbohydrate-deficient transferrin were increased both in acute alcoholic hepatitis (7.9 +/- 2.1%) and nonabstainers with alcoholic liver cirrhosis (7.4 +/- 2.8%), but not in abstainers with alcoholic liver cirrhosis (4.6 +/- 3.5%) or nonalcoholic liver disease (3.8 +/- 0.9%) (p < 0.001). In acute alcoholic hepatitis, the sensitivity and specificity were only 32% and 87% for absolute concentrations, respectively, but 79% and 97% for relative values of carbohydrate-deficient transferrin. The concentrations of carbohydrate-deficient and total transferrin in serum were strongly correlated (r = 0.60; p = 0.008). CONCLUSIONS: The relative value (% of total), but not the absolute concentration, of carbohydrate-deficient transferrin in serum is a useful marker of alcohol consumption in acute alcoholic hepatitis.     

The Role of Antisocial, Affective, and Childhood Behavioral Characteristics in Alcoholics' Neuropsychological Performance

Chronic alcoholics demonstrate cognitive deficits when compared with nonalcoholics. These deficits are typically attributed to the direct effects of ethanol and its metabolites on the central nervous system (CNS). There are other factors, however, that differentiate alcoholics from controls, such as personality or behavioral characteristics. These factors may affect neuropsychological performance and thus alter the interpretation of alcoholic cognitive deficits as resulting solely from alcohol's toxic effects. To investigate this question, male and female alcoholics and peer nonalcoholic controls were compared on personality, behavioral, and cognitive measures. Alcoholics had greater numbers of antisocial behaviors, childhood behavioral disorder symptoms (CBD), and affective symptomatology, and had poorer neuropsychological performance than controls. The three personality and behavioral factors were positively intercorrelated with each other, and were negatively related to cognitive performance. The CBD factor proved to be the most consistent predictor of neuropsychological performance for both alcoholics and controls, and males and females. While the behavioral factors differentiated alcoholics from controls and predicted performance, significant differences between the groups in cognitive performance still remained when these factors were taken into account.     

Increased Acid Sphingomyelinase Activity in Peripheral Blood Cells of Acutely Intoxicated Patients With Alcohol Dependence

Background:  Acid sphingomyelinase (ASM; EC 3.1.4.12) hydrolyses membrane sphingomyelin into the bioactive lipid ceramide and is thus involved in different cellular processes such as differentiation, immunity, or cell death. Activation of ASM has been reported in particular in conjunction with the cellular stress response to several external stimuli, and increased ASM activity was observed in a variety of human diseases. Ethanol-induced activation of ASM has been observed in different cell culture systems, thus raising the question about the effect of alcohol intoxication in human subjects on ASM activity in vivo.
Methods:  We determined ASM activity in peripheral blood mononucleated cells of 27 patients suffering from alcohol dependence. Patients were classified according to their blood alcohol concentration at admission, and ASM activity was determined repeatedly from all patients during alcohol withdrawal.
Results:  Acutely intoxicated patients displayed significantly higher ASM activity than patients in early abstinence (Mann–Whitney U test: Z  = − 2.6, p  = 0.009). ASM activity declined in acutely intoxicated patients to normal values with the transition from the intoxicated state to early abstinence (Wilcoxon test: Z  = −2.7, p  = 0.007). At the end of withdrawal, ASM activity was significantly increased again compared to the early phase of abstinence in both patient groups (Wilcoxon test: Z  = −2.691, p  = 0.007 and Z  = −2.275, p  = 0.023, respectively).
Conclusions:  Alcohol-induced activation of ASM occurs in human subjects and might be responsible for deleterious effects of ethanol intoxication. Chronic alcohol abuse may induce deregulation of sphingomyelin metabolism in general, and this impairment may cause side effects during withdrawal from alcohol.     

Impact of donor-specific antibodies on long-term graft survival with pediatric liver transplantation

BACKGROUNDIn a previous paper, we reported a high prevalence of donor-specific antibody (DSA) in pediatric patients with chronic rejection and expressed the need for confirmation of these findings in a larger cohort.AIMTo clarify the importance of DSAs on long-term graft survival in a larger cohort of pediatric patients.METHODSWe performed a retrospective analysis of 123 pediatric liver transplantation (LT) recipients who participated in yearly follow-ups including Luminex testing for DSA at our center. The cohort was split into two groups according to the DSA status (DSA-positive n = 54, DSA-negative n = 69). Groups were compared with regard to liver function, biopsy findings, graft survival, need for re-LT and immunosuppressive medication.RESULTSDSA-positive pediatric patients showed a higher prevalence of chronic rejection (P = 0.01), fibrosis (P < 0.001) and re-transplantation (P = 0.018) than DSA-negative patients. Class II DSAs particularly influenced graft survival. Alleles DQ2, DQ7, DQ8 and DQ9 might serve as indicators for the risk of chronic rejection and/or allograft fibrosis. Mean fluorescence intensity levels and DSA number did not impact graft survival. Previous episodes of chronic rejection might lead to DSA development.CONCLUSIONDSA prevalence significantly affected long-term liver allograft performance and liver allograft survival in our cohort of pediatric LT. Screening for class II DSAs in combination with assessment of protocol liver biopsies for chronic antibody-mediated rejection improved early identification of patients at risk of graft loss.     

Changes in Neutrophil Oxidative Potential in Patients Undergoing Cardiopulmonary Bypass with Polypropylene Hollow Fiber Oxygenators

Neutrophil oxidative metabolism, C3d and beta 2 microglobulin levels, were assessed in nine consecutive patients undergoing cardiopulmonary bypass surgery with polypropylene hollow fiber oxygenators for open cardiac operations. Generation of oxygen free radicals by neutrophils was measured as luminol-enhanced chemiluminescence after stimulation with opsonized Zymosan and phorbol myristate acetate. A significant increase in light emission was detected by using both of the chemiluminescence stimulators. Moreover, a remarkable and significant increase in C3d levels was found already at 10 min. Conversely minimal changes in levels of beta 2 microglobulin were detected during cardiopulmonary bypass surgery. These data suggest that the impact of the patient blood with the foreign surface of cardiopulmonary bypass results in activation of phagocyte cells with increased potential in oxygen consumption. These effects could be partially complement-mediated.     

Adenoviras-mediated expression of human CD59 on xenogeneic endothelial cells: Protection against human complement-mediated lysis and induction of cellular activation by adenoviral transduction

Abstract: The expression of human regulators of complement activation in endothelium of a transplanted organ is an approach to overcoming the complement (C)-mediated rejection of a xenograft. We designed a replication-deficient adenovirus (Ad) containing the human CD59 cDNA (AdCD59) in order to induce expression of human CD59 on xenogeneic endothelial cells (EC) and confer protection against human C-mediated lysis. In vitro transduction of rat EC with AdCD59 led to consistent levels of CD59 expression in all cells and significantly reduced EC lysis induced by human xenogeneic natural antibodies (XNA) binding and C activation. In addition, we analyzed whether Ad transduction had modified the phenotype of EC and the xenogeneic recognition of EC by human serum. For this, we first demonstrated that transduction of rat EC with AdCD59 or an Ad carrying the lacZ gene (AdlacZ) markedly enhanced the expression of some cell-membrane markers of EC activation, including class I MHC antigens and rat CD59, to levels comparable to those obtained with TNFα Up-regulation of class I MHC antigens was observed for both mRNA and protein expression. In contrast, AdCD59-mediated gene transfer slightly increase intercellular adhesion molecule-1 (ICAM-1) and did not modify the expression of Crry, a rat complement regulatory molecule. Second, we showed that these phenotypic modifications of EC did not affect the expression of the Galαl-3Gal epitope and the binding of human XNA. In addition, neither AdlacZ-mediated transduction, nor TNFα treatment, modified the sensitivity of xenogeneic EC to human serum-mediated lysis. In conclusion, this study demonstrated that transduction of human CD59 with an adenoviral vector conferred resistance to xenogeneic cultured EC against human C-mediated lysis but is associated with cellular activation of transduced EC. This finding may have important implications for the in vivo protocols and strategies intended to generate safer Ad vectors.