Gastric inhibitory polypeptide in newly diagnosed ketotic type I (insulin-dependent) diabetics

Plasma concentrations of 5,000 daltons (5 kDa) immunoreactive gastric inhibitory polypeptide (IR-GIP) were measured before and up to 16 hours after the start of low-dose insulin treatment in newly diagnosed ketotic type I (insulin-dependent) diabetics. Nine patients were non-fasting. Before insulin treatment mean IR-GIP was 31 +/- 6 pmol/l (range 9-65 pmol/l). Four patients had IR-GIP concentrations in the normal fasting range (10-25 pmol/l), and nine patients had concentrations below 35 pmol/l. The remaining patients had IR-GIP concentrations in the normal postprandial range. A meal eaten after the start of insulin treatment caused an increase in IR-GIP in all patients. All patients had beta-cell function as estimated by plasma C-peptide. Individual changes in C-peptide were significantly correlated to changes in blood glucose both after the meal (r = 0.80, p less than 0.01) and during insulin treatment (r = 0.85 +/- 0.04). No correlation could be found between IR-GIP and blood glucose, C-peptide or insulin concentrations. Newly diagnosed ketotic type I diabetics have IR-GIP concentrations within the normal postprandial level. Hypoinsulinaemia, hyperglycaemia, and hyperketonaemia do not by themselves increase 5 kDa IR-GIP markedly above normal fasting levels.     

Illness-behaviour, attitude, and knowledge in newly diagnosed diabetics

Sixty-five consecutive patients with newly diagnosed type I diabetes, aged 15-52, were exposed to a systematic educational programme and followed up by three-monthly controls for two to four years. In order to identify psychic, social and behavioural factors associated with good metabolic control and appropriate adaptation to illness, they were clinically tested and filled in a questionnaire. The study shows that the illness and the therapeutic regime created few problems regarding practical circumstances of daily living, but there were a vast number of psychological problems: perceived disability, fatigue, fear, anger, strain, bad conscience, and perceived discrimination. The patients assessed the treatment regimen they had been taught as fair, but still the majority reported inadequate compliance and problems in relation to compliance, especially regarding dietary restrictions. The educational programme was evaluated by the patients as useful and satisfying. Actual illness-related knowledge, skills and compliance were not closely associated, suggesting that knowledge itself is an insufficient precondition to appropriate management of the illness. Social class and other social environment factors were not associated with illness-related behaviour and attitudes and neither was metabolic control. There were no psychological or social differences between the patients with good and those with poor control. A possible interpretation of these findings is that an increase of quality of life in diabetic patients requires separate efforts to increase metabolic control and to create appropriate psycho-social adjustment to the change in life situation.     

Measurement of immune complexes in insulin-treated diabetics

Insulin therapy produces anti-insulin antibodies the measurement of which by conventional radioimmunoassay depends on the presence of available combining sites to bind radiolabelled insulin. The availability of free antibody-combining sites depends on variables such as the molecular ratio of antibody to insulin, and the affinity of the various antibodies to the insulin antigen. An improved method for measuring insulin antibody in serum is described in which insulin-anti-insulin complexes are dissociated at acid pH and all liberated insulin is removed by charcoal adsorption prior to conventional radioimmunoassay. Increases in antibody titre after this acid dissociation charcoal-adsorption reflect the presence of circulating immune complexes in sera of diabetics.     

Depressed suppressor cell activity in patients with newly diagnosed insulin-dependent diabetes mellitus

Suppressor cell activity (SCA) was studied in twenty-eight patients with insulin-dependent diabetes mellitus (IDDM), both newly diagnosed and of longer standing. Suppressive effect of peripheral blood lymphocytes from the patients was tested after 48 hr of incubation with concanavalin A followed by inactivation. Suppression was measured as the ability of the lymphocytes to inhibit 3H-thymidine incorporation in concanavalin A-stimulated normal donor lymphocytes. SCA was expressed in relation to the activity of peripheral blood lymphocytes from simultaneously investigated healthy control individuals. The main findings were: (1) SCA was significantly depressed in newly diagnosed diabetics and (2) newly diagnosed patients displayed significantly lower SCA than did patients with duration of disease between 2 and 8 months and between 5 and 8 years, who had suppressor cell activities not significantly different from healthy individuals. Earlier studies have pointed to the significance of immune reactions in diabetogenesis. On this basis, and on the strength of our present findings, it is suggested that an impaired SCA, causing a decreased inhibition of aggressive lymphocytes, may be implicated in the pathogenesis of insulin-dependent diabetes mellitus.     

A randomized trial of intensive insulin therapy in newly diagnosed insulin-dependent diabetes mellitus

A period of early, intensive insulin treatment is thought to improve subsequent beta-cell function in insulin-dependent diabetes mellitus (IDDM). To study this hypothesis, we randomly assigned adolescents with newly diagnosed IDDM to receive either conventional treatment (n = 14) (NPH insulin, 1 U per kilogram of body weight per day, in two divided doses) or an experimental treatment (n = 12) (a two-week hospitalization with maintenance of blood glucose levels between 3.3 and 4.4 mmol per liter by continuous insulin infusion delivered by an external artificial pancreas [Biostator]). During the two-week intervention, the experimental-therapy group received four times more insulin than the conventionally treated group, and their endogenous insulin secretion was more completely suppressed, as evidenced by a urinary C-peptide excretion rate one seventh that of the conventionally treated group. After the first two weeks, both groups were treated similarly and received similar amounts of insulin. At one year, the mean (+/- SEM) plasma level of C peptide was significantly higher after mixed-meal stimulation in the experimental-therapy group than in the conventionally treated group (0.51 +/- 0.07 vs. 0.27 +/- 0.06; P less than 0.01). The experimental-therapy group also had better metabolic control, as evidenced by lower glycohemoglobin values (7.2 +/- 0.7 vs. 10.8 +/- 1.2 percent; P less than 0.01). We conclude that suppression of endogenous insulin by intensive, continuous insulin treatment during the first two weeks after the diagnosis of IDDM may improve beta-cell function during the subsequent year.     

HLA antigens of insulin-dependent diabetics

We describe three human proliferating T cell colonies, derived from mixed leukocyte culture with a non-diabetic individual (DR3 + 4) as the source of responding cells and an insulin-dependent diabetic patient (also DR3 + 4) as the source of stimulating cells. One colony detects HLA-Dw10 or a closely related antigen, and two detect an antigen that we call BO1 (Boston 1). BO1 is found so far on cells of all persons with DR5, about half of those with DRw6, and a particular subset of those with DR3. Among DR3-positive subjects, BO1 is positively correlated with HLA-B18 and BfF1, and negatively correlated with HLA-B8. These findings suggest that BO1 occurs in linkage disequilibrium with DR5, DRw6, and the haplotype B18, BfF1, DR3, the latter being common in southern Europe and reported previously to be a marker for insulin-dependent diabetes. In limited testing (21 subjects), BO1 was completely included in the supertypic specificity MT2, BO1 is a Class II HLA antigen, as demonstrated by blocking with monoclonal antibodies, but is distinct from all known antigens of the DR, MB(DC), MT, and SB series. It could be located on the same polypeptide chain as one or more of these antigen groups, however, particularly DR and/or MT.     

Low pancreatic lipase in insulin-dependent diabetics.

Serum samples obtained from 20 insulin-dependent diabetics (IDD), 23 non-insulin-dependent diabetics (NIDD) and 30 controls were assayed for their pancreatic lipase activity, immunoreactive trypsin concentration and glycosylated haemoglobin (HbA1) respectively. The distribution of serum pancreatic lipase activity in normal subjects and diabetics was nonparametric. The median serum lipase activity in IDDs (86 U/l) was significantly lower that that in controls (131 U/l, p less than 0.002) and NIDDs (126 U/l, p less than 0.001). There was a significant correlation between serum pancreatic lipase activity and serum IRT concentration (r = 0.65, p less than 0.001). Neither pancreatic lipase activity nor IRT was related to HbA1 concentrations. These data show for the first time that serum pancreatic lipase activity is diminished in IDDs.     

Migrating ability of tumor cells treated with immune sera

The action of antitumor sera (ATS) on the adhesive properties of L cells and of Ehrlich's ascites carcinoma cells was studied. The ability of the tumor cells to adhere to plastic and glass and to form rosettes with sheep's red blood cells was reduced after treatment with immune serum and, when injected into mice, fewer of these cells were held up in the lungs, spleen, and liver. The results show that antibodies may play an essential role in the metastasization of tumor cells.Research Center, N. I. Pirogov Second Moscow Medical Institute. N. F. Gamaleya Institute of Epidemiology and Microbiology, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR P. A. Vershilova.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 12, pp. 712–714, December, 1977.     

Free insulin profiles in insulin-dependent diabetics treated with one or two insulin injections per day

Twenty-four hour profiles of free insulin and blood glucose were determined in 12 healthy controls and 10 insulin-dependent diabetics treated with insulin regimens based on intermediate-acting insulin injected subcutaneously once or twice a day. The diabetics were ambulatory and in a good glycemic control, i.e. without hyperglycemic symptoms or frequent hypoglycemias and with HbA1 less than 9% (reference value 5.9-7.8%). Body weight was normal and median age (32 years) was the same in both groups. Free insulin was determined after polyethylene glycol precipitation of antibody-bound insulin. The controls had a low basal insulin level (median fasting value 3.9 mU/l) and postprandial peaks with a maximum within 30-60 min. There was no rise in plasma free insulin or blood glucose in the early morning hours. The free insulin profiles in the diabetics were highly unphysiological with hyperinsulinemia between the meals and during the night. The highest plasma free insulin value during the 24 hours was reached before lunch (approximately 5-fold compared to normals, p less than 0.01). Postprandially the free insulin concentrations did not reach the peak levels of the normals. After breakfast, blood glucose rose considerably in the diabetics (p less than 0.02 compared to normals) while the rise after lunch and dinner was not higher than in the healthy controls. The difficulties in glycemic control in the diabetic group, i.e. a blood glucose rise after breakfast and hypoglycemias in some patients, could largely be explained by the unphysiological insulin profiles.     

HLA-DR and DQ antigens in insulin-dependent diabetics in Ethiopia

Thirty-one Ethiopian insulin-dependent (or type I) diabetes mellitus (IDDM) patients and thirty-three healthy controls from the same ethnic background were typed for HLA-A, B, C, DR and DQ specificities. The frequencies of both DR3 and DR4 were significantly increased among IDDM patients (resp. p = 0.02, p = 0.01), confirming results in other populations. In contrast to observations in Caucasians, no significant negative association was found with TA10, a newly recognized DQ specificity, at least in the population studied here, whereas DQwl was more frequently observed among healthy controls (p = 0.01). Although this latter difference does not retain statistical significance after correction for the number of comparisons made, these findings may support previous results suggesting the existence of IDDM susceptibility genes associated with DR3 and DR4 and of IDDM resistance genes associated with DQ antigens.     

Circulating immune complexes in sera of patients infected with Echinococcus granulosus

Circulating immune complexes (CIC) were investigated by the C1q binding assay in sera of 23 patients infected with Echinococcus granulosus. For the 23 sera studied, nine were found to be positive in the test. When the samples were grouped according to the cyst localization, the highest rate of CIC positively was found in the group of sera from patients with pulmonary cyst; in this group, double diffusion (DD) and indirect haemagglutination (IHA) tests gave a low rate of positivity for antibodies directed against parasitic antigens. Rheumatoid factor, anti-nuclear and anti-mitochondrial autoantibodies were not detectable in patients' sera by indirect immunofluorescence technique (IIF). Anti-smooth muscle autoantibodies, detectable by IIF, were present in 56% of the sera and this positivity was higher in the hepatic (83%) than in the pulmonary form (40%).     

Diminished perception of inspiratory-resistive loads in insulin-dependent diabetics

Diabetes mellitus is known to be associated with impaired perception of sensory input from organs such as the heart. To determine whether diabetics have a diminished ability to perceive respiratory sensations, we compared the abilities of patients with insulin-dependent diabetes (n = 17) and nondiabetic controls (n = 13) to detect inspiratory-resistive loads. The subjects were evaluated as they breathed through a tube-manifold apparatus with resistance that was varied randomly. They indicated whenever they perceived increased resistance to inspiration. The threshold for detecting added inspiratory resistance was expressed as a fraction of the background resistance of the subject plus that of the apparatus. This fraction, known as the Weber fraction, was 0.53 +/- 0.19 (mean +/- SD) in diabetics with neuropathy, 0.38 +/- 0.24 in diabetics without neuropathy, and 0.29 +/- 0.15 in nondiabetic controls. The differences in the mean value of the Weber fraction among the three groups were significantly different from zero (F = 4.57, P less than 0.025). There was not a significant correlation between the Weber fraction and age, degree of autonomic dysfunction, pulmonary function, cigarette smoking, or degree of diabetic control. The Weber fraction correlated with the duration of diabetes (r = 0.57, P less than 0.02). We conclude that patients with insulin-dependent diabetes may have an impaired ability to perceive inspiratory-resistive loads. This increased threshold for the perception of respiratory sensations may lead to delayed recognition of pulmonary disease in diabetics.     

Soluble FcgammaRIIa inhibits rheumatoid factor binding to immune complexes

Soluble low-affinity receptors for IgG are known to inhibit immune complex (IC)-mediated inflammation, and expression by leukocytes is elevated in several inflammatory diseases. Immunoglobulin M (IgM) rheumatoid factors (RF), anti-Fc autoantibodies, are found in autoimmune diseases, such as rheumatoid arthritis (RA), as well as in normal immune responses. This study demonstrated that soluble FcgammaRIIa inhibits the interaction of rheumatoid factors with ICs. The recombinant soluble low-affinity FcgammaR, rsFcgammaRIIa, partially inhibited (30-70%) the rate of precipitation of soluble ICs by RF-positive RA sera. This required the normal interaction of FcgammaRIIa with Fc as the effect could be abrogated with the Fab fragment of the blocking mAb IV-3. Furthermore, rsFcgammaRIIa partially inhibited (40%) the binding of a monoclonal IgM RF (RF-AN) to an IC formed by IgG2 antibody binding to an antigen-coated biosensor chip. Since RF-AN has been characterized by crystallography to bind to the CH2/CH3 interface of the IgG-Fc, and leukocyte FcgammaRIIa binds to a distinct site centred on the lower hinge, this inhibition is uncompetitive. Some inhibition (15%) of staphylococcal protein A binding to IC was also observed. As soluble FcgammaRIIa disrupts Fc:Fc interactions in IgG-ICs, we propose that this alteration of the IC also reduces the accessibility of Fc portions in the IC, resulting in the partial inhibition of ligands, particularly IgM RF, which bind Fc. We propose that the high concentrations of soluble FcgammaR found during inflammation can affect the properties of ICs and their interaction with the immune system.     

Reduced complement-mediated immune complex solubilizing capacity and the presence of incompletely solubilized immune complexes in SLE sera.

Reduced complement-mediated solubilization (CMS) of pre-formed immune complexes (IC) was demonstrated in sera from 11 out of 12 SLE patients. The presence of incompletely solubilized endogeneous IC in SLE sera was indicated by the following findings: (1) When IC positive SLE sera with reduced CMS capacity were mixed with normal donor sera they inhibited the CMS of the latter sera. (2) Resuspended PEG (2.75%) precipitates obtained from SLE sera inhibited the CMS of normal donor sera. (3) Non-solubilized or incompletely complement solubilized IC in SLE sera give a strong response in the PEG-CC assay for IC. The IC activity of SLE sera was clearly reduced in this assay when the endogeneous IC were solubilized prior to testing. In contrast, sera of 14 rheumatoid arthritis (RA) patients exhibited normal CMS. IC which could be further solubilized by complement were not demonstrable although all RA sera were IC positive.     

Circulating immune complexes in old people and in diabetics: correlation with autoantibodies.

Circulating immune complexes (CIC) were detected by a solid-phase radioassay in 34% of fifty-three insulin-dependent diabetics (IDD) as compared to 18% of forty-five non-insulin-dependent diabetics (NIDD) and 14% of 173 control subjects. In control subjects, the prevalence of CIC increased with age and was higher in males than in females. In IDD, immune complexes were found with the highest frequency before the age of 30 and after 50. There was no significant difference between the incidence of CIC in old IDD and their age-matched controls. The same sera were also tested for the presence of the following autoantibodies; nuclear , thyroid, gastric, smooth and striated muscle; mitochondria, sub-maxillary and adrenal gland and liver-kidney microsome. Sera containing at least one antibody were found in 16.4% of controls, 55.3% of IDD and 40% of NIDD. The prevalence of autoantibodies increased with age in controls but not in IDD. Islet cell antibodies were present in 28.5% of IDD and 2.9% of control subjects; they were more frequent in young patients. CIC and autoantibodies were statistically associated both in controls and IDD; in the patients, CIC were associated not only with islet cell antibodies but also with other autoantibodies. The possible relation between autoimmunity, degenerative vascular diseases and CIC is discussed.     

Deficiency of monoclonal antibody (Leu 7) defined NK cells in newly diagnosed insulin-dependent diabetes mellitus

Peripheral blood from 11 newly diagnosed patients with insulin-dependent diabetes mellitus (IDDM) was studied for the proportion of monoclonal antibody (HNK 1, Leu 7) defined natural killer (NK) cells using a fluorescence-activated cell sorter analyzer. The proportion of Leu 7+ cells in patients with IDDM (7.0 +/- 4.0) was significantly (P less than 0.001) lower than in simultaneously studied healthy controls (16.8 +/- 7.0). A 2-yr-old boy with recent onset IDDM had a deficiency of Leu 7+ NK cells (6.1%), while his healthy identical twin had normal proportions of Leu 7+ cells (22.2%), when compared to a simultaneously studied healthy control. Two patients reexamined in remission and one other studied in remission alone, showed deficiency of Leu 7+ NK cells. This study demonstrates a quantitative deficiency of monoclonal antibody (Leu 7+) defined NK cells in newly diagnosed patients with IDDM that persists during remission of the disease and therefore appears to be independent of metabolic abnormality. The deficiency of NK cells may predispose genetically susceptible individuals to viral-induced islet cell injury, contributing to the pathogenesis of IDDM.     

Evidence for anti-tubulin autoantibodies in the form of immune complexes in human sera.

Anti-tubulin antibodies were studied in normal human serum either maintained at neutral pH to measure the free antibody activity (FAA) or treated at pH 2.8 to measure the total antibody activity (TAA): FAA + the antibody activity in the form of immune complexes (ICAA). Anti-tubulin antibody activities were assessed by measurements of the capacity of serum immunoglobulins to bind pure 125I-labelled tubulin in a liquid phase radioimmune assay or to immunoprecipitate unlabelled tubulin revealed by Western blot using anti-alpha- or anti-beta-tubulin monoclonal antibodies. Acid buffer-treated serum and untreated serum at a 1:200 dilution immunoprecipitated about 35% and 4% of labelled tubulin, respectively. TAA was therefore 8- to 10-fold higher than FFA. Anti-tubulin antibody titres corresponding to TAA and FAA were about 1:20,000 and 1:500, respectively. The Western blot analysis confirmed that the acid buffer-treatment of the serum dramatically increased the capacity of serum immunoglobulins to immunoprecipitate tubulin. TAA was studied in patients with Graves' disease with elevated FAA. TAA of the sera of control subjects and patients with Graves' disease were not significantly different, so an increase of FAA was related to a decrease of ICAA. These results indicate that (a) normal human serum contains high levels of anti-tubulin antibodies in the form of immune complexes which are dissociated by an acid buffer treatment, (b) these immune complexes exist in the presence of a small excess of free anti-tubulin antibodies, (c) the equilibrium between free and immune complex-bound anti-tubulin antibodies could be altered in patients with autoimmune diseases.