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D Vergani

Publications and source records attributed to D Vergani.

At least 91 records · Page 5Linked to original sources
PubMed1995

Cell cycling in HIV infection: analysis of in vivo activated lymphocytes.

Infection with HIV results in increased circulating levels of T lymphocytes expressing phenotypic markers of immune activation. In the present study, using three-colour immunofluorescence, we examined the cell cycle status of these activated cells. Activated (HLA-DR+, CD25+ and CD38+) CD4+ and CD8+ T lymphocytes in peripheral blood were analysed for DNA content in 15 HIV+ patients and 10 healthy age- and sex-matched control subjects. As expected, all HIV+ patients had elevated percentage levels of activated CD4+ HLA-DR+, CD4+ CD25+, CD8+ HLA-DR+, CD8+ CD25+ and CD8+ CD38+ T lymphocytes compared with control subjects (P < 0.001 for all). Percentage levels of CD4+ HLA-DR+ and CD8+ HLA-DR+T lymphocytes in the 'proliferative' (S-G2M) phase of the cell cycle were also higher in the HIV+ patients compared with controls (P < 0.001 for both). The percentage levels of proliferative CD4+ CD25+, CD8+ CD25+ and CD8+ CD38+ lymphocytes were, however, similar in HIV+ patients and controls, indicating that the proliferative fraction of cells in vivo was confined to the HLA-DR+ subset and absent from the CD25+ and CD38+ populations. Four HIV+ patients had grossly elevated levels of CD8+ lymphocytes which were CD38+ (> 95%) and confined to the pre-G0-G1 phase of the cell cycle, suggesting these may be cells committed to apoptosis. These observations indicate an increase in the proliferative capacity of HLA-DR+ T lymphocytes in HIV infection in vivo. The reduced DNA content in other populations (e.g. CD38+ CD8+ lymphocytes) of some patients with advanced HIV disease suggests that these cells are apoptotic. Thus our results define both proliferative and apoptotic processes as a spectrum of activation-related events in HIV infection.

ADP-ribosyl Cyclase↗
PubMed1995

Heterogeneity of liver/kidney microsomal antibody type 1 in autoimmune hepatitis and hepatitis C virus related liver disease.

Liver/kidney microsomal antibody type 1 (LKM-1), the serological marker of a subset of autoimmune hepatitis, is also present in a proportion of patients with hepatitis C virus (HCV) related chronic liver disease. To characterise further this autoreactivity and to evaluate whether an autoantibody giving an identical immunofluorescence staining, and detected in two different clinical conditions, involves the same antigenic target(s), sera from autoimmune and HCV infected patients were tested with native, recombinant, and synthetic antigens. Sixty five sera were selected on the basis of the typical immunofluorescence pattern: 50 patients had serological markers of HCV infection, the remaining 15 suffered from autoimmune hepatitis. The reactivity of each serum with rat and human microsomal fractions, full length human recombinant CYP2D6, and two synthetic peptides spanning the amino acid regions 257-269 and 373-398 of CYP2D6 was systematically investigated by immunoblotting. Fourteen (93%) sera from autoimmune hepatitis patients and 39 (78%) from HCV infected patients reacted with rat and/or human microsomal polypeptides of 39 kD, 50 kD, 58 kD, and 66 kD in different associations, the 50 kD band being the most frequently observed. Reactivity to CYP2D6 and its amino acid sequence 257-269 was significantly more common in autoimmune hepatitis than in HCV infected patients (p < 0.001 and p < 0.0003, respectively). LKM-1 reactivity is directed against heterogeneous and not entirely defined autoantigens. The main target in autoimmune sera is CYP2D6 and its 257-269 amino acid region, while sera from patients with HCV infection are more likely to recognise other microsomal targets, the molecular identity of which is currently unknown.

Adolescent↗
PubMed1995

Anti-liver cytosolic antigen type 1 (LC1) antibodies in childhood autoimmune liver disease.

Antibodies to liver cytosol antigen type 1 (anti-LC1), which recognize a 60-kd peptide contained in the liver cytosolic fraction, have been reported to define a subset of autoimmune hepatitis (AIH) either negative for other autoantibodies or positive for anti-liver kidney microsomal antibody type 1 (LKM-1) and to be best detected in immunodiffusion. To analyze the prevalence of anti-LC1 in childhood liver disease, we have tested the sera of 95 patients using immunoblot, indirect immunofluorescence, and immunodiffusion. Fifteen children had smooth muscle antibody (SMA) and/or anti-nuclear antibody (ANA)-positive AIH, 13 had anti-LKM-1-positive AIH, 14 had autoimmune sclerosing cholangitis (ASC) (all SMA and/or ANA positive), and 53 had non-autoimmune liver disease (10 had alpha 1-anti-trypsin deficiency [alpha 1-ATD], 11 had Wilson's disease [WD], 14 had Alagille's syndrome, and 18 had chronic hepatitis B virus [HBV] infection). Twenty healthy children were studied as controls. Anti-LC1 positivity in immunodiffusion and strong reactivity in immunoblot were found in 4 LKM-1- and 2 SMA/ANA-positive patients with AIH and in 1 patient with ASC, but in none of the patients with other liver diseases nor in controls. A weak 60-kd band was detected by immunoblot in 6 more patients with AIH (2 were LKM-1- and 4 were SMA/ANA-positive) and 6 patients with ASC, all anti-LC1-negative by immunofluorescence and immunodiffusion. No distinct clinical features characterized the anti-LC1-positive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Importance of persistent cellular and humoral immune changes before diabetes develops: prospective study of identical twins.

OBJECTIVES: To determine the pattern of cellular and humoral immune changes associated with insulin dependent diabetes before diabetes develops. DESIGN: Prospective study over 10 years of 25 non-diabetic identical twins of patients with insulin dependent diabetes. The non-diabetic twins were followed up either till they developed diabetes or to the end of the study. SETTING: Teaching hospital. SUBJECTS: 25 non-diabetic identical cotwins of patients with diabetes; 46 controls of the same sex and similar age tested over the same period. Of the 25 twins (total follow up 144 patient years), 10 developed diabetes (prediabetic twins); the remainder were followed up for a mean of 7.7 years. MAIN OUTCOME MEASURES: Results of glucose tolerance tests or fasting blood glucose concentrations at each sample point. Measurements of activated T lymphocytes, expressing the HLA-DR antigen, islet cell antibodies, and insulin autoantibodies in samples. RESULTS: All 10 prediabetic twins had both cellular and humoral changes initially and in most samples before diabetes was diagnosed (activated T lymphocytes in 39/40, islet cell antibodies in 45/47, and insulin autoantibodies to islet cells and insulin were detected infrequently (in 8/54, 6/69, and 0/69 samples, respectively). The combination of cellular and humoral (islet cell antibodies or insulin autoantibodies) immune changes were detected in all 10 of the prediabetic twins but in only one of the 15 non-diabetic twins (P < 0.001). The positive predictive value in this cohort of increased percentages of activated T cells and the presence of antibodies to islet cells or insulin on two consecutive occasions was 100%. CONCLUSION: Most of the twins had cellular or humoral immune changes at some stage. A combination of cellular and humoral immune changes and their tendency to persist is highly predictive of insulin dependent diabetes and distinguishes twins who develop diabetes from those who do not.

Adolescent↗
PubMed1994

Lymphocyte subset abnormalities, autoantibodies and their relationship with HLA DR types in children with type 1 (insulin-dependent) diabetes and their first degree relatives.

Type 1 (insulin-dependent) diabetes mellitus is associated with abnormalities of circulating lymphocyte subsets and autoantibodies. To investigate the prevalence of these in non-diabetic siblings and non-diabetic patients of children with Type 1 diabetes, we analysed T-cell subsets of function and activation in 31 families with an index case of Type 1 diabetes and related these to autoantibodies and HLA DR type. Using two and three colour cytofluorimetry, we studied total and activated (HLA-DR+) CD3+, CD4+, CD8+, lymphocytes and on CD4+ lymphocytes the CD45RA/RO "naive" and "memory" cell phenotypes. Diabetic children (mean duration of disease 3.1 years) had a reduced total lymphocyte count (p < 0.05), their non-diabetic siblings a reduced CD4+ T-helper cell count (p < 0.05), and their parents a reduced percentage and number of CD3+ T cells (p < 0.01 and p < 0.05) compared with age-matched control subjects. Diabetic children, their siblings and parents all had significantly increased levels of activated CD4+ T-helper cells (p < 0.01, p < 0.05 and p < 0.01). In diabetic children and their siblings there was a significant over-expression of the CD45RO "memory" cell marker and significant under-expression of the CD45RA "naive" cell marker, whilst these were normal in the parents. Islet cell antibody positive diabetic children had significantly higher levels of CD45RO-expressing CD4+ lymphocytes than those who were islet cell antibody negative (p < 0.05). Amongst the siblings and parents, possession of HLA-DR4 was associated with lower percentages of CD4+ and higher percentages of CD8+ T cells. These findings extend current knowledge about the role of immunoregulatory CD45RA/RO cells in Type 1 diabetes. In addition, they demonstrate lymphocyte subset abnormalities in unaffected family members, some of which may be influenced by HLA DR alleles.

Adult↗
PubMed1994

Primary and secondary liver/kidney microsomal autoantibody response following infection with hepatitis C virus.

Liver/kidney microsomal autoantibody type 1 (LKM-1), which characterizes a subtype of autoimmune hepatitis, is also found in some patients with chronic hepatitis C virus (HCV) infection. Whether HCV and LKM-1 are accidentally or causally related is unknown. This case report describes a child who became infected by HCV after liver transplantation for end-stage liver disease caused by alpha 1-antitrypsin deficiency. LKM-1 was detected by immunofluorescence, anti-microsomal reactivity by Western blotting, anti-HCV and anti-GOR by immunoenzymatic assays, and HCV RNA by polymerase chain reaction. Two weeks after HCV infection, immunoglobulin (Ig) M LKM-1 appeared, followed by IgG1 LKM-1, with titers increasing to 1/2560; antibodies to a 50-kilodalton liver microsomal protein appeared 2 months later. Sera from day 1 posttransplant became positive for HCV RNA. HCV RNA was also detected in a liver biopsy specimen obtained 3 months after surgery. The patient did not produce anti-HCV and anti-GOR antibodies throughout the study and had no histological evidence of hepatitis. The temporal relationship between HCV infection and LKM-1 production suggests that HCV may trigger a primary autoimmune response. The lack of liver damage attributable to autoimmunity or viral infection may be caused by immunosuppression.

Antibody Formation↗
PubMed1994

Relationship between the tumour-associated antigen 90K and cytokines in the circulation of persons infected with human immunodeficiency virus.

A tumour-associated antigen known as 90K has been found in high concentrations in the serum of patients infected with human immunodeficiency virus (HIV) even in the absence of neoplastic complications. In order to investigate the relationship between the production of 90K and soluble inflammatory mediators, we studied serum concentrations of the antigen, tumour necrosis factor-alpha (TNF-alpha), interleukin-I-alpha (IL-I-alpha), interferon-gamma (IFN-gamma), IFN-alpha, neopterin and beta 2-microglobulin (beta 2-m) in patients with non-neoplastic HIV infection at various stages of disease and in control persons. The antigen was detected in all those studied but its concentration was higher in HIV-infected patients compared with controls (P < 0.001), increasing progressively with advancing stages of disease. There was a negative correlation between concentrations of 90K and IL-I-alpha in patients in U.S.A. Centers for Disease Control groups II and III (P < 0.02) and also between that of 90K and both TNF-alpha (P < 0.01) and IL-I-alpha (P < 0.05) in control persons. The results indicate that 90K is not merely a tumour-associated antigen and that its production may be part of immune and inflammatory responses in the absence of neoplasia. The correlation between the concentrations of 90K and of some cytokines in asymptomatic patients and healthy persons suggests that 90K may be part of a network of immune and inflammatory reactants.

Adult↗
PubMed1994

Cellular expression of tumour necrosis factor-alpha and interferon-gamma in the liver biopsies of children with chronic liver disease.

The liver biopsies of patients with autoimmune liver diseases have a dense portal tract mononuclear cell infiltrate. To investigate whether these cells produce tumour necrosis factor-alpha and interferon-gamma, cytokines which could be involved in the autoimmune attack through a direct cytopathic effect and/or through induction/enhancement of major histocompatibility complex antigen expression, we immunohistochemically stained cryostat liver sections from 21 children with autoimmune liver disease and from 15 children with metabolic liver disorders and histological evidence of portal tract inflammation as controls. Tumour necrosis factor-alpha and interferon-gamma producing cells were detected simultaneously within the inflammatory cell infiltrate in the liver biopsies of 18 patients with autoimmune liver disease, but only one patient with a metabolic disorder was positive for tumour necrosis factor-alpha. There was a significant correlation between frequency of tumour necrosis factor-alpha and interferon-gamma producing cells, intensity of inflammatory cell infiltrate (p < 0.03 and p < 0.05, respectively) and transaminase levels (p < 0.008 and p < 0.03, respectively). These results suggest that tumour necrosis factor-alpha and interferon-gamma play a pathogenic role in autoimmune liver cell damage.

Adolescent↗
PubMed1994

Development of techniques for obtaining monodispersed human islet cells.

The aim of this study was to develop techniques to obtain monodispersed, human islet cells in large quantities, since these constitute a potentially transplantable beta cell mass with which to treat established type 1 diabetes, as well as provide the most appropriate substrate for studying the immune pathogenesis of the disease. Human islets were isolated from the pancreas of beating-heart organ donors by collagenase digestion. Enzymatic (collagenase types II, IV, V, and XI, trypsin, DNAse, and hyaluronidase) and chemical (EDTA and EGTA) conditions were then used to find the optimum requirements for digestion of intact human islets into their constituent cells. The combination of trypsin with EDTA provided the highest yield of monodispersed islet cells (963 cells/islet) and highest viability (88%). DNAse with EGTA gave high yields (710 cells/islet) but viability was low (55%). Lower yields and viability were obtained using collagenase types II, IV, V, and XI (47-243 cells/islet; viability 45-62%), hyaluronidase (410 cells/islet; 75% viability), and EDTA alone (253 cells/islet; viability 43%). Human islet cells monodispersed using trypsin 0.125 mg/ml in 0.1 mM EDTA retained an insulin secretory response to glucose, and had intact surface class I MHC molecules when analyzed immediately after digestion by flow cytofluorimetry. Our results indicate that functionally intact, single, human islet cells may be obtained in abundance, and provide a potential substrate for islet cell transplantation in the treatment of patients with type 1 diabetes.

Cell Separation↗
PubMed1994

Differences in immune recognition of cytochrome P4502D6 by liver kidney microsomal (LKM) antibody in autoimmune hepatitis and chronic hepatitis C virus infection.

LKM-1 antibody, which characterizes a subtype of autoimmune hepatitis (AIH), is also found in some patients with chronic hepatitis C virus (HCV) infection. It has been suggested that HCV initiates autoimmunity through molecular mimicry, because there is partial identity between HCV and cytochrome P4502D6 (CYP2D6), the putative target of LKM-1. Whether CYP2D6 is the target of LKM-1 in HCV-related liver disease, however, is controversial. To clarify this issue, we have studied by phage plaque assay and Western blot the reactivity to recombinant CYP2D6, isolated from a human liver cDNA library, in 55 patients with LKM-1, 18 (14 females, median age 12 years) anti-HCV-negative, with classical AIH, and 37 (27 females, median age 52 years) anti-HCV-positive. Reactivity to CYP2D6 was found in 72% of the anti-HCV-negative, but only in 27% of the anti-HCV-positive patients (P < 0.001), although immunofluorescence LKM-1 titres were similar in the two groups. In addition, to investigate whether the antibody responsible for the LKM-1 fluorescent pattern also reacts with CYP2D6, we have determined the specificity of LKM-1 antibodies present in the supernatant of lymphoblastoid B cell lines obtained from two patients with LKM-1-positive AIH. An oligo/monoclonal antibody thus generated gave both the typical fluorescent pattern and reacted with CYP2D6. Our results show that whilst antibodies producing the characteristic LKM-1 fluorescent pattern can react with CYP2D6, not all LKM-1-positive sera do so, particularly if obtained from patients with chronic HCV infection. This suggests that LKM-1 in HCV infection recognizes epitopes or antigens different from those targeted in AIH.

Adolescent↗
PubMed1994

Interleukin-1 alpha, soluble interleukin-2 receptor, and IgG concentrations in cystic fibrosis treated with prednisolone.

The cytokines interleukin-1 and interleukin-2 participate in the inflammatory response, and may contribute to hypergammaglobulinaemia G and the development of lung injury in cystic fibrosis. Anti-inflammatory treatment with corticosteroids may attenuate this response. The effect of a 12 week course of oral prednisolone on spirometry and serum concentrations of interleukin-1 alpha (IL-1 alpha), soluble interleukin-2 receptor (sIL-2R), and IgG was investigated in 24 children with cystic fibrosis. Prednisolone was administered, in a double blind and placebo controlled manner, at an initial dose of 2 mg/kg daily for 14 days and tapered to 1 mg/kg on alternate days for 10 weeks. The treated group (n = 12) experienced an increase in forced expiratory volume in one second and forced vital capacity at 14 days, however, these changes were smaller at 12 weeks. In the treated group, change in pulmonary function was associated with decreased serum IgG and cytokine concentrations. Prednisolone suppresses serum concentrations of these cytokines, which may participate in the inflammatory response, the excessive synthesis of IgG, and airflow obstruction observed in cystic fibrosis patients.

Adolescent↗
PubMed1994

Effect of fresh frozen plasma and gammaglobulin on humoral immunity in neonatal sepsis.

Fresh frozen plasma and intravenous immunoglobulin are used as prophylaxis against, and for the treatment of, neonatal infection. It is assumed that any beneficial effect is mediated through the humoral immune factors contained in each preparation. The effect of fresh frozen plasma and intravenous immunoglobulin on humoral immune markers (immunoglobulins and IgG subclasses, complement components and activation products, and C reactive protein) was investigated over a 24 hour period after their randomised administration to 67 infants with suspected infection. Thirty infants without suspicion of infection were studied as controls. Compared with control infants, infants with suspected infection had increased concentrations of C reactive protein, reduced concentrations of fibronectin, and increased concentrations of the complement activation marker C3d, but similar concentrations of IgG, IgG subclasses, IgA, and IgM. After intravenous immunoglobulin treatment (500 mg/kg) concentrations of total IgG and all IgG subclasses increased, as did IgA and complement component C4. Concentrations of C reactive protein decreased after intravenous immunoglobulin treatment and were significantly lower than baseline after 24 hours. In contrast, no change in IgG or IgG subclass concentrations occurred after fresh frozen plasma administration. At 24 hours after fresh frozen plasma administration, concentrations of IgA, IgM, and C4 were significantly higher than baseline and serum IgA was significantly higher than in infants tested 24 hours after intravenous immunoglobulin treatment. These results confirm the rational basis for intravenous immunoglobulin treatment but question the value of fresh frozen plasma, particularly in the light of its attendant problems as an untreated blood product.

Antibody Formation↗
PubMed1994

Hepatic expression of tumour necrosis factor-alpha in chronic hepatitis B virus infection.

AIM: To determine the hepatic expression of tumour necrosis factor-alpha (TNF alpha) in patients with chronic hepatitis B virus (HBV) infection. METHODS: Frozen liver biopsy sections from 19 patients with chronic HBV infection were studied, 12 of whom were HBeAg positive and 10 serum HBV DNA positive. Hepatic expression of TNF alpha was determined using immunohistochemistry. RESULTS: Only infiltrating mononuclear cells showed immunoreactive staining for TNF alpha (median 2, range 0-3; n = 19) which appeared as diffuse positive staining material in the cytoplasm. Patients with active liver disease, assessed histologically and biochemically, had a higher level of expression, both in the number of TNF alpha positive cells and the proportion of TNF alpha positive infiltrating mononuclear cells. There was no correlation between the expression of TNF alpha and serological parameters of viral infection (HBeAg and HBV DNA status and HBV DNA concentrations). CONCLUSION: Hepatic expression of TNF alpha is increased in chronic HBV infection and is related to the activity of liver disease and not to the level of HBV replication.

Adult↗
PubMed1994

Increased expression of T-cell markers of immunological memory associated with protection from type I diabetes. A study of identical twins.

Disturbances in the balance of CD4+ helper T-lymphocytes expressing the surface molecules CD45RA and CD45R0, which define naive and memory populations, respectively, are present at diagnosis of type I diabetes. In a prospective study over 10 years, these subsets were analyzed in samples obtained from 18 identical twins of patients with type I diabetes, 8 of whom became diabetic (prediabetic twins), whereas the rest remained nondiabetic after at least 8 years follow-up and are now unlikely to develop the disease (diabetes-protected twins). At the beginning of the study, percentage levels of naive (CD45RA+) CD4+ lymphocytes were significantly elevated in prediabetic twins compared with diabetes-protected twins (P < 0.05) and remained so throughout the study (P < 0.01). Percentage levels of naive cells in diabetes-protected twins were significantly reduced compared with control subjects both at the beginning and throughout the study (P < 0.05, P < 0.01, respectively). In contrast, diabetes-protected twins at the beginning of the study had elevated percentage levels of memory (CD45R0+) CD4+ lymphocytes that persisted throughout the study compared with prediabetic twins (P < 0.05 for both). Percentage levels of memory cells in prediabetic twins were significantly reduced compared with control subjects both at the beginning and throughout the study (P < 0.01, P < 0.05, respectively). Increased percentage levels of a population of CD4+ lymphocytes coexpressing CD45RA and CD45R0 were seen in both twin groups compared with control subjects at entry into and during the study (P < 0.05 for all), but persisted only in the prediabetic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

High prevalence of autoantibodies to glutamic acid decarboxylase in long-standing IDDM is not a marker of symptomatic autonomic neuropathy.

Immune reactivity to the enzyme glutamic acid decarboxylase (GAD), a pancreatic islet autoantigen, is present at the diagnosis of insulin-dependent diabetes mellitus (IDDM). Because GAD is also highly expressed in the nervous system, we investigated the presence of autoantibodies to the isoform GAD65 in patients with diabetic neuropathy, which is a debilitating complication of the disease. We studied 39 patients with autonomic and somatic neuropathy, 28 patients matched for age and IDDM duration, and 13 patients with a shorter duration of IDDM, all with no diabetic complications, as well as 50 recently diagnosed diabetic patients, 23 neurologic patients with idiopathic autonomic failure unrelated to IDDM, and 72 healthy subjects. An immunoprecipitation radioligand assay was used to detect anti-GAD65 autoantibodies with in vitro transcribed and translated human islet GAD65 as antigen. Autoantibodies to GAD65 were present in 56% of the diabetic patients with neuropathy, 57% of the long-duration and 69% of the short-duration diabetic control subjects, 78% of the recently diagnosed patients, and 13% of the nondiabetic neuropathic patients. Among the diabetic patients with neuropathy, there was no correlation between the presence of anti-GAD65 antibodies and the presence of autoantibodies to sympathetic ganglia, vagus nerve, or adrenal medulla structures identified by immunofluorescence. Our study shows that anti-GAD65 antibodies are present in a high proportion of patients with diabetic neuropathy but are not exclusively associated with it, rendering it unlikely that they have a role as a disease marker or that they are pathogenetic.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗