Selective reactions in antibody-dependent cell-mediated cytotoxicity

Selective reactions associated with HLA specificity were sought in antibody-dependent cell-mediated cytotoxic tests against HLA-typed lymphoblastoid lines using operationally monospecific HLA sera and effector cells from healthy individuals. Precise detection of HLA specificities was disturbed by the presence of natural antibodies in HLA antiserum and the effect of the serum and cells on target cell viability. Detection of HLA specificity was improved by absorption of the serum to remove natural antibodies and correction of the results for extraneous cell and serum effects.     

Function of cryopreserved human effector cells in antibody-dependent, cell-mediated cytotoxicity

Cells active in an ADCC model were studied for their ability to withstand cryopreservation. For this model, we used the [3H]proline microcytotoxicity assay with fibroblast target cells and a serum containing lymphocyte-dependent antibody reactive with the alloantigens on those target cells. Human blood effector cells active in this system can be successfully cryopreserved with minor dimunition in function with standard techniques and concentrations between 9 and 12% DMSO.     

Effect of human leukocyte interferon on hepatitis B virus infection in patients with chronic active hepatitis

Four patients with chronic hepatitis B infection and chronic active hepatitis were treated with human leukocyte interferon. Three of them had consistently elevated levels of circulating Dane-particle markers, including Dane-particle-associated DNA polymerase activity, hepatitis B core antigen and Dane-particle-associated DNA. Parenteral interferon administration at a dosage between 6.0 X 10(3) and 17 X 10(4) U per kilogram per day was associated with a rapid and reproducible fall in all Dane-particle markers in the three patients. The suppressive effect was transient when the interferon was given for 10 days or less but appeared to be more permanent when administration was prolonged for a month or more. In addition, long-term interferon therapy was associated with a marked fall in hepatitis B surface antigen in two of three patients and a disappearance of e antigen in two of two patients. Interferon may be useful in limiting carrier infectivity or eradicating chronic infection.     

Inhibition of antibody-dependent cell-mediated cytotoxicity (ADCC) as a means of detection of immune complexes in the sera of patients with thyroid disorders and bronchogenic carcinoma

Circulating immune complexes in the sera of patients with thyroid disorders or bronchogenic carcinoma were investigated using an assay system based on the inhibition of the ADCC activity of rat spleen cells. Increased inhibition, as compared with that of the sera of age and sex matched controls, was found in patients with thashimoto thyroiditis, primary hypothyroidism and bronchogenic carcinoma. The degree of inhibition in the first two groups was markedly increased compared with control sera of the same IgG content. However, the results in the lung cancer group were slightly but not significantly greater than in controls with the same level of IgG. Increased IgG levels were found in patients with thashimoto thyroiditis and thyrotoxicosis, and also in patients with bronchogenic carcinoma who had mediastinal gland involvement. The lower level of sensitivity of the assay system was approximately 600 ng added aggregated IgG, corresponding to a concentration of 6mu g/ml in the sample assayed. It is possible that circulating immune complexes may exist in lung cancer, but at a level below that of the present assay system.     

Antibody-dependent cell-mediated cytotoxicity in rheumatoid arthritis. Effect of rheumatoid serum fractions on normal lymphocytes

Reduced antibody-dependent cell-mediated cytotoxicity (ADCC) was demonstrated in lymphocytes of patients with rheumatoid arthritis (RA). Rheumatoid factor (RF) positive sera inhibited ADCC of normal lymphocytes by reacting both with effector and target cells (sensitized chicken red blood cells). These sera were fractionated by specific adsorption or gradient ultracentrifugation, and isolated RF or RF negative fractions were tested for their ability to inhibit ADCC by reacting with normal human lymphocytes or target cells. RF was ineffective on normal lymphocytes but it strongly inhibited the reaction by interaction with target cells. IgG RF negative fractions of certain sera were inhibitory by direct interaction with effector cells.     

Interleukin-1-producing plasma cells in close contact with hepatocytes in patients with chronic active hepatitis

BACKGROUND/AIMS: In chronic active liver diseases (CALD) with viral aetiology, a population of plasma cells localised in the piecemeal necrosis areas was previously detected by means of autoradiography after in vitro 3H-proline incorporation, a method which proved much more sensitive than conventional immunohistochemical procedures. These plasma cells, characteristically located in niches among hepatocytes, in close contact with collagen fibrils, have been hypothesised to exert a role in fibrogenesis stimulation, and particularly in collagen synthesis, possibly through secretion of lymphokines. Specifically, we investigated the presence of interleukin-1, well known to play a crucial role in inflammation and production of collagen by epithelial cells, and to be present in activated plasma cells of myeloma. METHODS: The immunohistochemical localisation of interleukin-1beta in biopsies of patients suffering from chronic active hepatitis was studied, using an affinity-purified rabbit polyclonal antibody. RESULTS: The strongest interleukin-1beta immunostaining was observed in the above-described plasma cell population, identified by anti-immunoglobulin antibodies, and 3H-proline incorporation. CONCLUSIONS: The ability of plasma cells to produce interleukin-1 during viral CALD suggests that in these pathologies plasma cells play a major role, mainly of paracrine nature. Interleukin-1, possibly together with other mediators, might in turn stimulate the production of collagen. Hepatocytes of the piecemeal necrosis area appear to be possible candidates for this synthesis, as they show a significant labelling after 3H-proline incorporation, which is absent from hepatocytes far from necrotic areas.     

In vitro reduction of virus infectivity by antibody-dependent cell-mediated immunity

Germ cell mutagens are among the most important chemicals for which chemopreventive agents should be sought and mechanistically defined. These mutagens may include environmental chemicals as well as drugs. In this investigation, the literature was reviewed for substances antimutagenic (or anticlastogenic) to compounds identified as mutagens in at least two germ cell studies. A complete matrix of test results was prepared to identify commonly tested pairs of germ cell mutagens and antimutagens. The categories of antimutagens most tested included vitamins, fatty acids, thiols, tannins and other phenolics. The most frequently studied mutagens were benzo[a]pyrene, cyclophosphamide, mitomycin C, and bleomycin. Based on the availability of the most relevant data, the analysis presented here focused on in vivo tests, specifically on bone marrow cytogenetics. The results indicated that antimutagens commonly found in the diet or endogenously in the body effectively antagonized the cytogenetic damage induced in the bone marrow by most of the germ cell mutagens studied to date. Bone marrow micronucleus and chromosomal aberration assays, which detect systemically active mutagens, may be predictive of similar mitigating effects in germ cells. Test results from antimutagenicity studies in germ cells, though limited, were comparable to the results from studies in the mouse bone marrow micronucleus test.     

Serum hepatitis G virus RNA in patients with chronic viral hepatitis

OBJECTIVES: The hepatitis G virus (HGV) is a newly described flavivirus that affects a high proportion of patients with chronic viral hepatitis: our objective was to determine what role HGV might play in the course of disease. METHODS: We evaluated stored serum samples from 108 patients with chronic hepatitis B and 99 patients with chronic hepatitis C who participated in trials of alpha-interferon or ribavirin for the presence of hepatitis B virus (HBV) DNA and hepatitis C virus (HCV) RNA by branched DNA and for the presence of HGV RNA by polymerase chain reaction (PCR), using primers from the NS5 region of the genome. RESULTS: Initially, 20 (19%) patients with hepatitis B and 11 (11%) with hepatitis C had HGV RNA in their serum. Patients with and without HGV infection were similar with regard to clinical features, laboratory tests, and hepatic histology. HGV RNA levels fell during interferon therapy and became undetectable in those receiving the highest doses; however, HGV RNA levels returned to pretreatment values when therapy was stopped. With ribavirin therapy, HGV RNA levels did not change. Two- to 12-yr follow-up serum samples were available from 17 initially HGV RNA-positive patients, of whom only 10 (59%) were still positive. CONCLUSIONS: HGV infection is common among patients with chronic hepatitis B and C but has little effect on the short-term course of disease or response to therapy. HGV RNA levels are suppressed but not eradicated by alpha-interferon and are unaffected by ribavirin treatment. Spontaneous loss of HGV RNA occurs over time in a proportion of patients.     

Asymptomatic intrahepatic choledochal cyst associated with chronic active hepatitis C

A rare case of asymptomatic congenital choledochal cyst (Todani Type V) associated with chronic active hepatitis C is reported. A 45 year-old man was admitted for work-up of localized cystic dilatation of the intrahepatic bile ducts after effective interferon treatment for chronic active hepatitis C. Radiologic examination revealed localized cystic dilatation of the intrahepatic bile ducts in the atrophic left lobe. A left hepatic lobectomy was performed because malignancy had not been excluded. Macroscopic examination of the resected specimen revealed cystic dilatation of the intrahepatic bile ducts. Histologically, there was no evidence of malignancy. Hepatic lobectomy is the treatment of choice for Type V cysts if the disease is confined to a single lobe. Choledochal cysts should be excised to eliminate the potential for cholangitis, lithiasis, and carcinoma.     

Autoimmune hepatitis and autoimmune manifestations in patients with chronic viral hepatitis

Mucosal adherence and germ tube formation have been considered as important virulence factors of Candida albicans. We investigated 11 clinical isolates (among them six isolates from oesophageal thrush) for quantification of adherence to buccal epithelial cells and germ tube formation in the continuous flow culture in vitro, and correlated the results with the clinical data of the patients. Adherence varied considerably between the different C. albicans strains. Strains recovered from clinically, culturally and serologically confirmed oesophageal thrush adhered stronger to buccal epithelial cells. Isolates from cases with heavy colonisation but clinically without candidosis were less adherent. Only after 30 min germ tube formation was observed in the continuous flow culture. Strains with stronger adherence also showed significantly faster and increased germ tube formation. The patients with oesophageal thrush did not suffer any particular immunosuppression such as HIV infection, although in most cases chronic alcoholism was apparent. We conclude, that in cases with minor immunosuppression the expression of the virulence factors adherence and germ tube formation plays an important role in the pathogenesis of candidosis, whereas it may be of less importance in cases with severe immunosuppression. In the latter they may, however, influence outcome.     

Evaluation of side effects of interferon-alpha in 72 patients treated for chronic active hepatitis C

Interferon alfa (INF alpha), which is used in chronic active viral hepatitis, presents some safety problems. Side effects observed in 72 treated patients with chronic active hepatitis C are analysed in this retrospective study. Doses used were 3 or 9 M IU, three times a week, for 12 to 24 weeks. There were no contra-indications to the treatment and all patients had the factors predictive of a satisfactory therapeutic response. Apart from general debility, there were side effects in 65 of the 72 patients as follows: flu-like syndrome (n = 39), gastrointestinal (n = 29), dermatological (n = 24), haematological (n = 23), neurological (n = 20), cardiovascular (n = 6) and thyroid (n = 6) disorders. For 30 per cent of the patients, the dose was decreased (n = 6) or the treatment was withdrawn, temporarily (n = 5) or permanently (n = 10). These results are in accordance with those published and emphasize the need for clinico-biological monitoring during and after treatment. Indeed delayed thyroid disorders appear to be relatively common.     

The class of antibody involved in the antibody-dependent cell-mediated lysis of chicken erythrocytes

Affinity chromatographic experiments demonstrated that IgG was the class of antibody involved in the in vitro lysis of chicken erythrocytes by antibody and normal mouse effector cells. Further experiments designed to investigate the subclass of IgG involved, indicated that IgG2a was active and provided further evidence for the inactivity of IgM, either in the native 19S or chemically degraded 7S form. From the results obtained, the possibility of ADCC-inducing activity in the other IgG subclasses could not be excluded.     

Osteodystrophy in patients with chronic hepatitis and liver cirrhosis

Bone mineral density (BMD) of the lumber vertebrae and factors related to bone metabolism were determined in patients with chronic viral hepatitis and patients with liver cirrhosis to clarify correlations between hepatic dysfunction, considered to be one of the causes of hepatic osteodystrophy, and decrease in bone mass. BMD of the second to fourth lumbar vertebrae was determined with a Lunar (Madison, WI, USA) DPX, a dual-energy X-ray absorptiometry diagnostic system. BMD was significantly lowest in patients with liver cirrhosis, followed by patients with chronic hepatitis, and healthy subjects, in this order. There was a significantly positive but weak correlation between albumin and BMD. Levels of 25(OH)D and 1,25(OH)2D were significantly lower in patients with liver cirrhosis than in those with chronic hepatitis. BMD and vitamin D were decreased in all patients whose cholinesterase (ChE) was below 0.3 delta pH. Urinary pyridinoline (Upyr) was significantly higher in the patients with liver cirrhosis, in whom bone mass was decreased, than in the patients with chronic hepatitis, whereas serum osteocalcin levels were distributed in the upper normal range in patients with chronic hepatitis and those with liver cirrhosis. There was a positive correlation between 25(OH)D and serum osteocalcin levels in patients with liver cirrhosis. These results indicate that osteogenesis is decreased and suggest that the decrease in BMD which occurs in viral liver cirrhosis, probably related to decreased, bone formation and slight promotion of bone resorption, reflects deranged hepatic function. This is the first report of Upyr and urinary deoxypyridinoline (UDpyr) determination in patients with liver cirrhosis and patients with chronic hepatitis. The negative correlation of Upyr and UDpyr with ChE is a novel finding.     

Complement level in serum from patients with chronic hepatitis

In persons with chronic active hepatitis (35) and chronic persistent hepatitis (23) the CH 50 values, Clq, Cls, C4, C3, C5, and C9 as well as Cl Inh and C3A levels have been determined. The concentration changes of complement (C) were not conditioned by the existence in serum HBs. The degree of changes in values of C in all patients is in determinate relation with the levels of bilirubin, transaminases and immunoglobulins (G, M, A). The degree of determinate changes of C depends on the severity of clinical picture. The degree of Cl Inh elevation is in correlation with intensity of complement activation. The noticed dissociated values of subcomplements Clq and Cls suggest the presence of immune complexes which could influence the HBsAg detection.