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Biomedical subjects

D Vergani

Publications and source records attributed to D Vergani.

At least 199 records · Page 11Linked to original sources
PubMed1986

Diabetes and autonomic neuropathy: an immunological association?

Lymphocytic infiltration of autonomic ganglia found at autopsy and a strong clinical association with iritis suggests that diabetic autonomic neuropathy might have an immunological basis. We measured levels of circulating immune complexes, complement (C3, C4), complement breakdown products (C3d), and insulin antibodies in diabetics with autonomic neuropathy and a history of iritis (n = 17), compared to diabetics of similar age and duration with autonomic neuropathy but no history of iritis (n = 20), and with uncomplicated insulin-dependent diabetics (n = 23), together with normal controls (n = 26). We found higher levels of circulating immune complexes in patients with autonomic neuropathy (irrespective of iritis) compared to normal controls, and differences in C3d levels suggesting complement activation. C4 levels were unexpectedly normal in the diabetics with autonomic neuropathy, in contrast to the uncomplicated insulin-dependent diabetic controls. Insulin antibody levels showed no difference between the three groups of diabetics. These findings suggest that immunological mechanisms may be implicated in the aetiology of diabetic autonomic neuropathy and that further studies are indicated.

Adult↗
PubMed1986

Complement activation in uveitis.

To determine whether complement is activated in uveitis we have measured plasma levels of C3d, a sensitive indicator of complement activation. Increased levels of C3d were found in 11 of 15 patients with idiopathic uveitis, 13 of whom had circulating immune complexes containing complement components. Since during complement activation potent mediators of inflammation are generated, it is suggested that the activation of complement, possibly triggered by uveal deposition of immune complexes, has an important role in the pathogenesis of uveitis.

Adolescent↗
PubMed1986

Functional characterization of peripheral blood lymphocytes in chronic HBsAg carriers.

Increased proportions of suppressor/cytotoxic T cells have been identified in the peripheral blood of chronic HBsAg carriers and to investigate a possible relationship to T cell cytotoxicity against autologous hepatocytes, suppressor cell activity, viral replication and the histological type of disease, 42 consecutive HBsAg carriers undergoing a liver biopsy have been investigated. The proportion of suppressor/cytotoxic lymphocytes directly correlated with T cell cytotoxicity to autologous hepatocytes and both were higher in those with HBeAg in serum than in those with anti-HBe or those on corticosteroid therapy. There was no relationship to underlying histological classification. In contrast, suppressor cell regulation of IgG producing cells was unrelated to the proportion of suppressor/cytotoxic lymphocytes in peripheral blood or HBeAg status, but impaired function was associated with chronic hepatitis, particularly chronic active hepatitis. These data suggest that the increased proportion of suppressor/cytotoxic lymphocytes in the peripheral blood of HBsAg carriers represents an increase in the cytotoxic and not the suppressor cell subset and that this is a consequence of active viral replication and not of the severity of hepatic inflammation. Defective suppressor cell function may be one factor in the development of chronic active hepatitis, but is not reflected by alterations in the T4:T8 ratio.

Adolescent↗
PubMed1986

In vitro study of IgG production and concanavalin A induced suppressor cell function in acute and chronic hepatitis B virus infection.

To investigate the relationship between liver damage and immune regulation in hepatitis B virus (HBV) infection, 68 patients with HBsAg in serum and a spectrum of liver damage have been studied and compared with 25 controls. In HBsAg carriers, spontaneous IgG production was elevated only in those with chronic active hepatitis (P less than 0.05) whilst those with less severe inflammation had values comparable to normals. Concanavalin A (Con A) induced suppressor cell regulation of IgG producing cells was impaired in those with chronic active hepatitis (P less than 0.01) and those with chronic persistent hepatitis (P = 0.05) and there was a correlation in both groups of patients with the severity of portal tract inflammation (P less than 0.05). In contrast those with minimal liver damage had values in the normal range. Patients presenting with acute hepatitis B also had elevated spontaneous IgG production (P less than 0.01) and impaired Con A induced suppressor cell regulation of IgG production (P less than 0.01). Sequential study of three patients prior to the detection of HBsAg in serum and subsequently during and after acute hepatitis B showed that such abnormalities were transient and closely related to the onset of liver damage.

Adult↗
PubMed1986

Immune factors in narcolepsy.

Most but not all subjects with the narcoleptic syndrome have the human leukocyte antigen (HLA) DR2 (and DQ1). The narcolepsy-DR2 association is the highest disease-HLA linkage known, and occurs in nonfamilial as well as familial cases of the narcoleptic syndrome. In other forms of daytime drowsiness, there is no relationship with a specific HLA, although some subjects considered to have "essential" hypersomnolence probably have the narcoleptic syndrome. The cause of the narcoleptic syndrome remains unknown, although in a few instances the condition follows infection. There is no evidence for a circulating sleep factor in the blood or in the cerebrospinal fluid of narcoleptic subjects, and no unequivocal marker of cellular immunity has yet been found. However, a few subjects with the narcoleptic syndrome have oligoclonal bands or raised immunoglobulin concentration in the cerebrospinal fluid. It is highly likely that the narcoleptic syndrome is an immune-mediated disorder, occurring in a genetically susceptible (DR2/DQ1-positive) subject.

Female↗
PubMed1985

Genetically determined low C4: a predisposing factor to autoimmune chronic active hepatitis.

Of 26 patients with autoimmune chronic active hepatitis (CAH) starting in childhood 18 (69%) had low C4 and 5 (19%) had low C3 serum levels. Impaired hepatic synthesis and immune-consumption were unlikely since transferrin levels were normal in all patients, albumin levels were persistently low in only 3, and only 3 had raised levels of activation fragment C3d. C4d was normal in all patients studied. In the families of 12 probands with low C4, 7 parents had low C4 and 2 had levels which were at the lower limit of normal. 5 of 10 siblings from 5 families had low C4. These results suggest that low C4 levels in CAH are genetically determined. C4 phenotyping in 20 patients and in 26 parents showed that 90% and 81%, respectively, had null allotypes at either the C4A or C4B locus compared with 59% in controls, indicating that defective expression of structural genes may contribute to the observed C4 deficiency.

Adolescent↗
PubMed1985

Spontaneous bacterial peritonitis in children with chronic liver disease: clinical features and etiologic factors.

We analyzed the clinical and bacteriologic features of 12 episodes of spontaneous bacterial peritonitis (SBP) in 11 children (four boys, median age 5.5 years) with chronic liver disease. All patients had cirrhosis and ascites; four had hypersplenism, and one was asplenic. Symptoms included increasing abdominal distention, pyrexia, abdominal pain, gastrointestinal disturbance, and encephalopathy. Nine had rebound tenderness on abdominal palpation, and 12 had reduced bowel sounds. The most frequent organisms isolated from culture of ascitic fluid were Streptococcus pneumoniae (nine). Klebsiella (two), and Haemophilus influenzae (one); blood cultures grew identical organisms in nine. Seven patients died despite intensive antibiotic therapy. In the 3 months prior to onset of SBP, defective yeast opsonization and reduced serum concentration of C4 were found in all nine children tested; eight had reduced concentration of C3. Functional deficiency of all complement components was present in four tested within 1 to 5 months of the onset. In contrast, only eight of 59 cirrhotic children without SBP had low C3, and eight had defective yeast opsonization, although 35 had low C4 values. Four of the patients with SBP and low C3 and C4 concentrations had normal concentrations at the time of diagnosis of liver disease 2 to 5 years previously. Opsonization of type III pneumococci was reduced in sera from three patients who subsequently developed pneumococcal peritonitis. The incidence of SBP in children with chronic liver disease is similar to that in adults, as are the clinical features. Our observations suggest that complement deficiency induced by chronic liver disease may be important in the pathogenesis of SBP.

Adolescent↗
PubMed1985

T suppressor cell function and number in children with liver disease.

Con A stimulated suppressor cell function and the proportion of suppressor T cells were reduced in children with untreated chronic active hepatitis (CAH) but were normal in corticosteroid treated CAH patients, patients with severe acute hepatitis and inactive chronic liver disease. Adults with CAH also have defective suppressor function but a normal proportion of T suppressor cells. This difference may account for the observation that relapse after treatment withdrawal is less frequent in children than in adults.

Adolescent↗
PubMed1985

Immunoregulation of immunoglobulin production in normal infants and children.

Proportion of T cell subsets, spontaneous and PWM stimulated immunoglobulin production by peripheral blood lymphocytes and concanavalin A- (Con A) stimulated suppressor cell activity on immunoglobulin production by B cells was studied in 37 infants and children, to investigate changes of these parameters with age. Proportion of suppressor/cytotoxic (T8+) T lymphocytes was significantly lower in children below the age of 5 years, while there was no difference in proportion of total T lymphocytes (T3+) and helper/inducer (T4+) T cells. Spontaneous production and secretion of IgG and IgM by lymphocytes from children of all age groups was similar to that found in adults, but lymphocytes of children below the age of 10 years showed a low response to PWM stimulation. The activity of Con A-induced suppressor cells in inhibiting B cells producing immunoglobulins was almost absent in infancy, gradually increased during childhood and reached adult levels in teenagers. A significant association between the proportion of T8+ cells and Con A-induced suppression of B cell proliferation and a relationship between T4+ cells and spontaneous Ig production indicated the increasing maturity with respect to both number and function of peripheral blood lymphocyte subsets with advancing age.

Adolescent↗
PubMed1984

Pathways to complement activation during cardiopulmonary bypass.

Complement activation was assessed in 34 patients undergoing cardiopulmonary bypass. Arterial concentrations of complement fragments Ba and C3d rose in all patients, the increase in Ba preceding that of C3d. At the same time as complement fragments were being generated the arterial neutrophil count fell. These findings suggest (a) that complement activation is initiated by the alternative pathway during cardiopulmonary bypass and (b) that complement activation mediates loss of neutrophils during bypass. Complement mediated loss of neutrophils during the analogous setting of haemodialysis is the result of leucosequestration in the pulmonary vasculature. During cardiopulmonary bypass the lungs are out of circuit, so that activated leucocytes may sequester in other target organs. This may be an aetiological factor in the multi-organ failure occasionally seen after uneventful cardiopulmonary bypass.

Adult↗
PubMed1984

Pathogenesis of insulin-dependent diabetes: a role for activated T lymphocytes.

Expression of HLA DR antigens on T lymphocytes indicates that these cells are actively involved in an immune response. Raised levels of activated T lymphocytes were found in 14 of 15 recently diagnosed but in only 7 of 28 long-standing insulin-dependent diabetics. 9 of the recently diagnosed patients retested 6 months later still had high levels of activated T lymphocytes. Even long-standing insulin-dependent diabetics had significantly higher levels of activated T lymphocytes than non-insulin-dependent diabetics and healthy controls. 5 of 7 unaffected co-twins of recently diagnosed insulin-dependent diabetics had high levels of activated T cells; this increase persisted in 2 retested 6 months later, when mildly impaired glucose tolerance had developed. These results confirm that there is an active cellular immune reaction in newly diagnosed insulin-dependent diabetics which may precede the disease and persist for at least 6 months after its appearance.

Adolescent↗
PubMed1983

Chronic liver disease in children with leukemia in long-term remission.

Liver disease during chemotherapy and after its completion was studied in 103 leukemic children in long-term remission. Seventy developed chronic liver disease during therapy; 22 out of 56 with adequate follow-up showed persisting abnormality or deterioration of liver function after stopping therapy. In 38 studied prospectively, biopsies were obtained at treatment withdrawal. Five showed chronic lobular, 17 chronic persistent, 9 chronic active hepatitis whereas 7 had minimal changes. These children had transiently detectable serum hepatitis-B virus (HBV) markers during (44.4%), at completion of (7.8%) and subsequent to (48.3%) chemotherapy. Serum HBV markers correlated significantly with both severity of histologic changes (P less than 0.05) and persistent biochemical abnormalities for over 6 months after treatment suspension (P less than 0.001). No direct relationship was found between drug administration and liver damage. The data from the study suggest that in leukemic children viral infections contribute to chronic liver damage, which can jeopardize the long-term prognosis of acute leukemia.

Acute Disease↗
PubMed1983

Low serum C4 concentrations: an inherited predisposition to insulin dependent diabetes?

Twenty two out of 86 insulin dependent diabetics had serum C4 concentrations below the normal range. None of 41 non-insulin dependent diabetics tested had low concentrations. Low C4 values were seen in insulin dependent diabetes irrespective of the duration of the disease and did not appear to correlate with complement activation. There was a close correlation in C4 values between identical cotwins, even when only one was diabetic. These results suggest that a low serum C4 concentration is an inherited phenomenon and may predispose towards the development of insulin dependent diabetes.

Adolescent↗
PubMed1983

Immune responses in patients with obstructive jaundice of infancy. Anti-LSP and Clq binding in sera.

To investigate possible involvement of immune responses in the pathogenesis of obstructive jaundice in infancy we measured antibody to liver specific lipoprotein (LSP) by radio immunoassay and immune complexes by their ability to bind C1q in sera from 16 patients with extrahepatic biliary atresia and 16 with neonatal hepatitis and 13 age matched controls. Anti-LSP was present in 6 of 16 with preoperative biliary atresia and 6 of 16 with hepatitis. Mean percentage C1q bound was higher in hepatitis (22 SD 15%) than preoperative biliary atresia (11.1 SD 2.3%). Nine of 16 hepatitis patients had elevated C1q binding as compared with 1 of 16 with biliary atresia. The highest value for anti-LSP and C1q binding were found in sera from patients with histologically severe hepatitis and hepatitis associated with specific viral or bacterial causes. Anti-LSP was significantly raised 5 months post-operatively in all of 6 patients with biliary atresia and poor biliary drainage but only 2 of 5 survivors. Elevated C1q binding was detected in 6 of 7 with poor drainage and 1 of 7 survivors at the same stage. Anti-LSP and C1q binding fell in 4 patients with neonatal hepatitis on recovery. These findings suggest that immunological mechanisms, possibly involving antibody to hepatocyte membrane components and immune complexes, may be involved in the pathogenesis of progressive liver disease in biliary atresia.

Antigen-Antibody Complex↗