[A new serologic test makes it possible to diagnose hepatitis C].
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Blood Donors↗
Biomedical subjects
S Hermodsson
Publications and source records attributed to S Hermodsson.
Mother to infant transmission of hepatitis C virus infection.
Eight women with chronic hepatitis C virus (HCV) infection during pregnancy gave birth to 11 children. Five of these children had elevated ALT, but only two had increased levels in more than one sample. All children tested before 6 months of age were positive for anti-HCV at most up to 7 months of age and then became negative. One child with a maximum ALT level of 8.4 mukat/l however, regained anti-HCV positivity at 12 months of age, and a liver biopsy at 21 months of age showed resolving hepatitis. Passively acquired HCV antibodies are obviously found in newborns of anti-HCV-positive mothers with chronic hepatitis. In 1 of 11 children, active anti-HCV production and concomitant liver disease suggested mother to infant transmission of hepatitis C virus infection.
Alanine Transaminase↗
A cell-to-cell mediated interaction involving monocytes and non-T/CD16+ natural killer (NK) cells is required for histamine H2-receptor-mediated NK-cell activation.
Histamine (10(-4) to 10(-7) M) augmented natural killer cell cytotoxicity (NKCC) of human CD16+, non-T lymphocytes in vitro against the NK-sensitive target cells K562 erythroleukaemic, Molt-4 lymphoma, Chang liver cells and against Epstein-Barr virus (EBV)-transformed, NK-insensitive Daudi B-lymphoblastoid target cells by a mechanism of action involving a prostaglandin- and interleukin 1 (IL-1)-independent accessory function of monocytes. No evidence for the production of intermediary, NK-enhancing cytokines by histamine was obtained, indicating a cell-to-cell mediated interaction between monocytes and NK cells as a plausible mechanism of action for the NK-augmenting effect. Monocytes recovered by countercurrent centrifugal elutriation (CCE), but not monocytes recovered by adherence, reconstituted the effect of histamine when added to non-adherent NK cells. The development of NKCC in response to histamine was time-dependent with (i) an induction phase, dependent on the presence of accessory monocytes and ongoing histamine H2-receptor activation (half-maximal response required approximately 30 min treatment of large granular lymphocyte (LGL)-enriched lymphocytes and monocytes with histamine), and (ii) an effector phase, independent of the presence of monocytes or histamine receptor activation. Histamine-activated mononuclear cells (MNC) continued to exert augmented cytotoxicity for at least 8 h after removal of histamine and monocytes. In several experiments, histamine-activated NK-effector cells killed greater than 90% of the target cells at low baseline NKCC. We suggest that histamine may have a role in non-specific tumour defence by regulating an earlier unrecognized interplay between monocytes and NK cells.
Antigens, Differentiation↗
Monocyte-mediated suppression of IL-2-induced NK-cell activation. Regulation by 5-HT1A-type serotonin receptors.
In the present study, the effects of serotonin on human natural killer (NK)-cell responsiveness to interleukin 2 (IL-2) was investigated. Concomitant treatment of human lymphocytes, enriched for NK effector cells by Percoll density-gradient centrifugation, with serotonin and IL-2 yielded a synergistic activation of NK-cell cytotoxicity (NKCC) in the presence but not in the absence of monocytes. The monocyte-dependent, regulatory effects of serotonin and/or IL-2 were prostaglandin-independent and could be reconstituted when monocytes, recovered by countercurrent centrifugal elutriation (CCE), were added to purified NK effector cells. The effects of serotonin on baseline and IL-2-activated NK cells were mimicked by the 5-HT1A receptor-specific agonists 8-OH-DPAT and (+)-ALK. Our data suggest that serotonin regulates NK-cell responsiveness to IL-2 via 5-HT1A receptors.
Cell Separation↗
Synergistic activation of human natural killer cell cytotoxicity by histamine and interleukin-2.
Interleukin-2 (IL-2) is recognized as a major activating signal for human natural killer (NK) cells. The presence of monocytes alters NK cell responsiveness to IL-2. Thus, while IL-2 effectively augments NK cell cytotoxicity (NKCC) in monocyte-depleted NK effector cells, it is relatively ineffective or even suppressive for NK cells in monocyte-containing, NK-cell-enriched mononuclear cell fractions. Here we report that concomitant treatment with IL-2 and the biogenic amine histamine synergistically augmented NKCC against K562 and Daudi target cells of CD3-/CD16+ human NK cells in the presence but not in the absence of monocytes. Addition of peripheral-blood monocytes, recovered by countercurrent centrifugal elutriation, to purified NK cells abrogated IL-2 induced NK cell activation, reconstituted the synergistic, NK-activating effects of histamine and IL-2, and strongly reduced baseline NKCC. The effects of histamine on baseline NKCC and on NK cell responsiveness to IL-2 were related to counteraction of monocyte-mediated NK cell suppression. By contrast, histamine did not affect baseline or IL-2-induced NKCC in mixtures of NK cells and monocytes when the latter cells were recovered after adherence. The effect of histamine on NK cell responsiveness to IL-2 was mediated by H2-type histamine receptors, as judged by mimicry exerted by the specific H2 receptor agonist dimaprit, but not by an H2-receptor-inactive derivative of this compound, N-methyldimaprit, and blocking by the H2 receptor antagonist ranitidine. Experiments in which monocytes and nonadherent NK cells were separately pretreated with ranitidine prior to histamine treatment suggested that NK-regulatory effects of histamine were mediated by H2 receptors on monocytes. Our data suggest that histamine may provide an important signal in the regulation of NK cell responsiveness to IL-2.
Antigens, Differentiation↗
An immunopharmacological analysis of adrenaline-induced suppression of human natural killer cell cytotoxicity.
The circulating catecholamine adrenaline effectively suppressed human natural killer cell cytotoxicity (NKCC) when added to mixtures of effector lymphocytes and 51Cr-labelled target cells in a 4-hour 51Cr release assay in vitro. The effect was mimicked by the beta 2-receptor agonist terbutaline but not by the beta 1-receptor agonist prenalterol or the alpha 1/alpha 2-receptor agonist clonidine. Adrenaline-induced NKCC suppression was completely and potently antagonized by the mixed beta 1/beta 2-receptor antagonist propranolol and the selective beta 2-receptor antagonist ICI 118,551 but not by the beta 1-selective antagonist metoprolol. By comparing the adrenaline sensitivity of high-density (HD) and low-density (LD) lymphocytes, fractionated by Percoll density gradient centrifugation, we found that HD cells appeared more sensitive to adrenaline-induced suppression than LD cells. In both types of effector cells, adrenaline significantly suppressed NKCC at a final concentration of 10(-11) M. Pretreatment of LD effector cells with IFN-alpha reduced the NKCC suppression by subsequent adrenaline treatment. Pretreatment with recombinant IL-2 virtually abolished the response to adrenaline. This effect was noted also when IL-2 and adrenaline were incubated simultaneously during the 4-hour 51Cr release assay. Our data suggest a role for adrenaline, via lymphocyte beta 2-receptor activation, in the regulation of natural killer cells.
Adrenergic beta-Agonists↗
Interleukin-2 can induce suppression of human natural killer cell cytotoxicity.
By interaction with monocytes, interleukin-2 (IL-2) suppressed natural killer (NK) cell cytotoxicity (NKCC) of human, Percoll-fractionated, low-density mononuclear cells. The NK-suppressive effect of IL-2 was independent of de novo formation of prostaglandins or protein since it was unaffected by treatment with indomethacin and cycloheximide, respectively. A monoclonal antibody to the p55 (beta) moiety of the IL-2 receptor (anti-Tac/anti-CD25) blocked IL-2-induced NKCC suppression but did not affect the NK-enhancing effect of the lymphokine. We conclude that IL-2 exerts a monocyte-dependent, IL-2 beta-receptor mediated suppressive influence on human NK cells.
Cyclooxygenase Inhibitors↗
Cerebrospinal fluid changes in HIV-1 infection.
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Acquired Immunodeficiency Syndrome↗
Role of serotonin in the regulation of human natural killer cell cytotoxicity.
Addition of serotonin to mixtures of target cells and natural killer (NK)-enriched human mononuclear cells (MNC) in a 4-hr 51Cr-release assay strongly augmented NK cell cytotoxicity (NKCC) vs K562, Chang, or Molt-4 target cells. The effect was dose dependent at serotonin concentrations of 10(-4) to 10(-7) M, expressed at several effector to target cell ratios, and required the presence of accessory monocytes. A 5-HT1-specific receptor agonist, 8-OH-DPAT, mimicked the enhancing properties of serotonin with similar potency. Equimolar concentrations of the mixed 5-HT1/5-HT2 receptor antagonist cyproheptadine, but not the 5-HT2-specific antagonist ketanserin, completely blocked the serotonin-induced NKCC enhancement. Monocyte/NK cell mixtures incubated with serotonin for 1 hr produced a soluble factor that could enhance the cytotoxicity of autologous, NK-enriched cells depleted of monocytes, which did not respond to serotonin alone. The factor displayed no IFN or IL 2 activity as judged by the lack of antiviral activity and inability to support the growth of an IL 2-dependent cell line. In the presence of monocytes, serotonin (10(-5) M) was considerably more effective than human IFN-alpha or IFN-gamma at optimal concentrations and was about equally effective as IL 2 at a final concentration of 50 U/ml in a short-term NK assay. The potency and efficacy for serotonin were similar to that earlier reported for histamine in monocyte-containing effector cells. The NKCC-enhancing effect of serotonin was additive to that induced by IFN-alpha, IFN-gamma, or IL 2, but not to histamine. The presented data suggest an earlier unrecognized, serotonin receptor-mediated regulation of human NK cells.
8-Hydroxy-2-(di-n-propylamino)tetralin↗
Interferon and beta 2-microglobulin in patients with common variable immunodeficiency or selective IgA deficiency.
The production of interferon (IFN) after stimulation of peripheral blood mononuclear cells with Sendai virus or phytohemagglutinin was studied in patients with common variable immunodeficiency (CVID) or selective IgA deficiency. Cells from CVID patients produced significantly more Sendai virus-induced (alpha) and mitogen-induced (gamma) IFN than cells from healthy control subjects. By contrast, some patients with selective IgA deficiency produced subnormal amounts of IFN-alpha. Neither IFN-alpha nor IFN-gamma was detectable in sera from the two categories of patients using radioimmunoassays with sensitivity limits of 5-10 international units per milliliter. With the aid of a more sensitive bioimmunoassay, however, antiviral activity was detected more frequently in sera from patients with CVID than in sera from control individuals. Acid treatment and absorption with anti-IFN-alpha and anti-IFN-beta sera indicated that the antiviral activity was due to IFN, with no preponderance of any particular IFN type. Determination of beta-2-microglobulin (beta 2M) concentrations revealed that CVID patients had markedly, and IgA-deficient patients moderately increased serum levels of this substance, as compared to healthy blood donors. Since IFN enhances the synthesis of beta 2M the finding of increased levels of this substance in CVID would be consistent with the observed hyperproduction of IFN. The present findings are concordant with earlier observations of increased natural killer cell activity in at least some forms of CVID and suggest that increased activity of the IFN/natural killer cell system provides a mechanism which may compensate for the defective B cell function in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Differential effects of histamine receptor antagonists on human natural killer cell activity.
In this study we investigated the modulation of natural killer (NK) cell activity by various histamine receptor antagonists in vitro. The histamine H2-receptor antagonists cimetidine, ranitidine and tiotidine suppressed NK cell cytotoxicity (NKCC) at a high concentration (10(-3) M). Cimetidine enhanced NKCC of Ficoll-Hypaque-separated lymphocytes and of lymphocytes enriched for NKCC by Percoll density gradient centrifugation. The enhancing effect of cimetidine was dose-dependent at final concentrations of 10(-4)-10(-7) M and did not require the presence of adherent cells/monocytes. Ranitidine did not affect NKCC over a wide range of concentrations. Tiotidine strongly enhanced NKCC of low-density, large granular lymphocyte-enriched mononuclear cells (MNC) in the presence of adherent cells/monocytes, but was ineffective in nonadherent effector cells. All H2-receptor antagonists clearly antagonized histamine-induced NKCC enhancement in monocyte-containing effector cells. Clemastin, a specific H1-receptor antagonist, effectively suppressed NKCC. This effect was mimicked by a clemastin isomer with very low affinity for H1-receptors. We conclude that (1) cimetidine enhances NKCC in vitro by a mechanism of action that is not specifically related to antagonism of H2-receptors, (2) tiotidine displays mixed agonist/antagonist properties for MNC H2-receptors and (3) NK-suppressive properties of clemastin are unrelated to H1-receptor antagonism.
Cell Survival↗
Intradermal, subcutaneous or intramuscular administration of hepatitis B vaccine: side effects and antibody response.
The immune response after vaccination with a plasma-derived hepatitis B unit vaccine (MSD) administered intradermally or subcutaneously in 2 microgram doses was compared to the recommended 20 microgram dose administered intramuscularly. The trial was performed in 58 healthy volunteers 20-43 (mean 30) years old. No statistically significant difference in seroconversion rate was observed when the intradermal (i.d.) (2 micrograms) and intramuscular (i.m.) (20 micrograms) routes were compared (100% and 96% seroconversion, respectively). The 2 microgram dose administered subcutaneously gave a seroconversion rate of only 63%. The intradermal and i.m. routes also gave significantly higher mean titers of anti-HBs than the subcutaneous route (p less than 0.005). No severe reactions occurred and local reactions were seen almost exclusively in those vaccinated intradermally. These reactions included mainly discoloration, itching and nodule formation at the site of injection. The intradermal route ought to be considered for administration of hepatitis B vaccine since the dosage can be reduced to 1/10 without affecting the antibody response. Correct intradermal deposition of the vaccine is, however, crucial for an adequate immune response. This is probably the main disadvantage if large-scale vaccination programs should be carried out in developing countries using i.d. immunization.
Adult↗
Histamine H2-receptor-mediated regulation of human natural killer cell activity.
We have investigated effects of histamine on the spontaneous cytotoxic activity of human natural killer (NK) cells in vitro. Addition of histamine (10(-3) to 10(-7) M) to assay cultures of Percoll-fractionated mononuclear cells (MNC) and erythroleukemic K 562 target cells resulted in a strong enhancement of the cytotoxicity of low-density MNC, enriched for NK cell cytotoxicity (NKCC). No enhancing or suppressing effects of histamine could be detected after removal of monocytes/adherent cells from the effector cell suspensions. When unfractionated MNC were used as NK effectors, similar results were obtained, i.e., dose-dependent enhancement of NKCC by histamine in the presence of monocytes and lack of effect in nonadherent effector cells. Freshly isolated monocytes displayed low spontaneous cytotoxicity against K 562 targets and were not induced by histamine. The histamine-induced enhancement was mimicked by dimaprit, a specific histamine H2-receptor agonist, but not by N-methyldimaprit, a chemical control for H2-receptor agonist activity of dimaprit. Furthermore, the enhancement was completely antagonized by the specific histamine H2-receptor antagonists cimetidine and ranitidine. The effect of histamine could not be ascribed to endogenous interferon (IFN) production, since no IFN activity could be detected in histamine-treated MNC effectors. Also, the enhancing effects of histamine and human leukocyte IFN-alpha were clearly additive. On the basis of these findings, we suggest that histamine, via specific activation of H2 receptors, may be an important regulator of human NK cell activity.
Cell Separation↗
Impaired production of alpha and gamma interferon in asymptomatic homosexual males.
In vitro production of alpha interferon and gamma interferon was examined in cell cultures from 90 asymptomatic homosexual males and 19 healthy heterosexual male controls. The production of alpha and gamma interferon was significantly suppressed in homosexuals as compared to that in heterosexual controls (p less than 0.005 and p less than 0.001, respectively). Forty-one of the homosexuals produced less gamma interferon than any of the heterosexual controls. Antibodies against the human immune system virus (HIV) were found in eight homosexuals, who produced significantly less alpha and gamma interferon than did the HIV-seronegative homosexuals (p less than 0.02). Neither carriage of Entamoeba histolytica or Giardia lamblia nor serological evidence of infection with cytomegalovirus, Epstein-Barr virus or hepatitis B virus was associated with a significantly lower production of interferon than that found in homosexual males seronegative for these infections. No correlation was found between number of partners or practice of passive anal intercourse and production of interferons in homosexual men. It is concluded that the significantly lower production of both alpha and gamma interferon in asymptomatic homosexual males may play an important role in susceptibility to viruses, including HIV.
Adult↗
Evidence for a beta-adrenoceptor-mediated regulation of human natural killer cells.
Pretreatment of lymphocytes (16 hr, 37 degrees C) with adrenaline at final concentrations of 10(-7) to 10(-9) M, followed by removal of the drug, increased natural killer (NK) cell activity vs K562 leukemic cells in a 4-hr 51Cr-release assay. The most efficient concentration of adrenaline was 10(-8) M; mean increase of NK activity over base-line activity for all donors examined was 30%. However, the individual response to adrenaline pretreatment was variable; in some donors, the effect was equal to maximal interferon (IFN) stimulation. Effects of adrenaline pretreatment were consistently reduced to base-line activity by co-incubation with the nonselective beta-adrenoceptor antagonist propranolol at 100-fold higher concentrations. The enhancing effect of adrenaline (10(-8) M) pretreatment was also observed after 1-hr pretreatment; this effect was prevented by simultaneous incubation with propranolol but was not affected by dex-propranolol. Direct addition of adrenaline to lymphocyte/target cell mixtures was inhibitory at 10(-6) M adrenaline concentration. The inhibitory effect of adrenaline in this assay was again completely prevented by propranolol and unaffected by dex-propranolol. The observed stimulatory effect of adrenaline pretreatment could not be ascribed to IFN production. Data presented indicate a dual effect of adrenaline on NK cell activity and suggest both a positive and a negative beta-adrenoceptor-mediated regulation of human NK cells.
Cytotoxicity, Immunologic↗
Hepatic dysfunction after open-heart surgery.
In a prospective study, 93 patients were observed up to nine months after open-heart surgery using hypothermia, hemodilution and cold cardioplegia. In the first two weeks frequent determinations were made of serum aminotransferase, alkaline phosphatases (ALP), lactic dehydrogenase isoenzymes, gamma glutamyltransferase (GT), total and free bilirubin and bile acids. Plasma hemoglobin was measured at the end of the operation. After the first period, aminotransferases, alkaline phosphatases and bilirubin were determined monthly. On the first postoperative day almost all of the patients showed abnormal aspartate aminotransferase (ASAT) activity and ASAT/ALAT (alanine aminotransferase) greater than 1, and about 25% had hyperbilirubinemia. The findings suggested early postoperative leakage of enzymes not only from the myocardium, but also from the liver. After two weeks the patients presented another pattern of liver dysfunction, with abnormal ALAT in 50%, ASAT/ALAT less than 1, and abnormal ALP and GT in 28 and 45%, respectively. Eight patients were judged to have post-transfusion hepatitis of non-A, non-B type. Six of them had abnormal aminotransferases for more than six months.
Alkaline Phosphatase↗
Bioimmunoassays (BIAs) of human interferon.
Simple, sensitive, and reproducible assay systems for measurement of the biological activity of interferon are described. The methods used are based on the quantification of cell membrane-bound viral and cellular antigens in interferon-treated cells by enzyme immunoassays. To measure the antiviral activity, samples of human interferon are titrated in microplates with human or bovine cells. After incubation with challenge virus (vesicular stomatitis or herpes simplex virus) the cells are fixed with glutaraldehyde and assayed for viral antigens by enzyme-labeled antibodies. This assay permits the detection of less than 0.1 unit of interferon per milliliter, after optimization of several factors, such as type of cell, multiplicity of infection, temperature, and period of incubation. The effect of interferon on cellular antigens is measured in a similar way, by using peroxidase-labeled antibodies directed against beta 2-microglobulin. The two types of assays described appear suitable for kinetic experiments and for detection of interferons of different specificities in body fluids.
Antigens, Surface↗
Prevalence of markers of hepatotrophic viruses in alcoholics with symptomatic liver cirrhosis or pancreatitis.
The reason why similar amounts of alcohol consumption cause different types of organ damage in alcoholics is obscure. Recent studies indicate that hepatitis B virus infection may influence the development of liver cirrhosis in alcoholics. We investigated the prevalence of markers of viruses known to cause hepatitis (HAV, HBV, EBV, CMV) in two groups of patients, one with alcoholic pancreatitis without known liver cirrhosis and one with alcoholic liver cirrhosis without known pancreatitis. We found signs of past infection with HAV and HBV more often in alcoholics with liver cirrhosis than in patients with alcoholic pancreatitis or in age-matched controls.
Adult↗