Investigation of the mode of inheritance of insulin-dependent diabetes mellitus in Japanese subjects

Previous studies have shown that insulin-dependent diabetes mellitus is positively associated with HLA-DR4 and HLA-DR9 in Japanese populations. It was proposed that susceptibility to the disease is determined by a single HLA allele associated with both DR4 and DR9. DR genotypes in a Japanese population with insulin-dependent diabetes mellitus were determined by DRB/DQB RFLP analysis. A single disease-susceptibility-allele model was tested by the antigen-genotype-frequency-among-patients method. Recessive and additive inheritance of a single susceptibility allele were rejected. The DR9-associated disease-susceptibility allele in Japanese subjects is distinct from both the DR3- and DR4-associated susceptibility alleles in white Caucasians. The data suggest further complexity in the inheritance of HLA-associated susceptibility to insulin-dependent diabetes mellitus.

Strong association of insulin autoimmune syndrome with HLA-DR4

Insulin autoimmune syndrome is characterised by spontaneous hypoglycaemia without evidence of exogenous insulin administration, a high serum concentration of total immunoreactive insulin, and the presence of insulin autoantibodies in high titre. HLA typing of 27 patients with insulin autoimmune syndrome showed that all had DR4, which was present in only 43% of 51 healthy controls (odds ratio 72.1, p less than 2 x 10(-6), and 19 (70%) of the patients were positive for the allelic combination, Cw4, Bw62, and DR4. Analysis of the nucleotide sequences of the DRB1, DQA1, and DQB1 genes showed that all the patients had DRB1*0406, DQA1*0301, and DQB1*0302, compared with only 14% of the controls (odds ratio 281, p less than 1 x 10(-10). We conclude that the development of insulin autoimmune syndrome is associated with a strong genetic predisposition.

Human insulin-specific immunoglobulin G antibody and hypoglycemic attacks after the injection of gold thioglucose

A 56-year-old woman with granulomas of gold thioglucose in her hips exhibited recurrent bouts of hypoglycemic attacks. The first attack occurred 2 years after the last injection of gold thioglucose, when large amounts of extractable insulin and human insulin-specific antibody were noted in her serum. Histological examination of the resected granulomas showed marked infiltration of lymphocytes, plasma cells, and macrophages containing yellowish-brown granules, which proved to be gold by electron microscopy using X-ray microanalysis. After resection of the granuloma, however, the frequency of the hypoglycemic attacks decreased remarkably as well as the levels of both extractable insulin and human insulin-specific antibody.

An investigation of Japanese subjects maps susceptibility to type 1 (insulin-dependent) diabetes mellitus close to the DQA1 gene

Insulin-dependent diabetic and control subjects of Japanese origin were HLA-DRB1, -DQB1, and -DQA1 typed using restriction fragment length polymorphism analysis and sequence-specific oligonucleotide gene probing. The DQA1 allele DQA1*0301 was positively associated with the disease [48/52 (92%) diabetic patients versus 44/64 (69%) control subjects, Pc less than 0.03, RR = 4.97]. Alleles of the DRB1 and DQB1 genes showed no significant association with the disease. The frequency of DQB1 genotypes encoding the amino acid aspartic acid at position 57 of the DQ beta chain did not differ significantly between subjects with insulin-dependent diabetes mellitus (IDDM) and controls. These findings suggest that a susceptibility allele for IDDM in the Japanese is more closely associated with the DQA1 gene than the DQB1 gene.

Comparison of diagnostic criteria of IGT, borderline, and GDM. Blood glucose curve and IRI response

A 75-g oral glucose tolerance test (OGTT) was performed in 615 nonobese pregnant women (mean +/- SD age 29.7 +/- 4.3 yr) who were referred to the Division of Internal Medicine at our diabetes center because of glycosuria. Seventy-seven cases were found to have urinary glucose at the first trimester, 185 at the second trimester, and 353 at the third trimester. With their 75-g OGTT results, the diagnostic criteria of borderline (formulated by the Japan Diabetes Society), impaired glucose tolerance (IGT; defined by the World Health Organization [WHO]), and gestational diabetes mellitus (GDM; determined by the Japan Society of Obstetrics & Gynecology standards) were compared through blood glucose (BG) curves and immunoreactive insulin (IRI) responses. Borderline (fasting BG greater than or equal to 6.1 and less than 7.8 mM and 2-h BG greater than or equal to 6.7 and less than 11.1 mM) is neither diabetes nor normal. IGT is as referred to by the WHO. GDM exceeds two points of fasting BG greater than or equal to 5.6 mM, 1-h BG greater than or equal to 10.0 mM, or 2-h BG greater than or equal to 8.3 mM. Diabetes mellitus (DM) is as referred to by the Japan Diabetes Society (same as the WHO). The prevalence of abnormal glucose tolerance among all 615 pregnant women was 54.6% in borderline, 24.5% in IGT, 7.3% in GDM, and 3.4% in DM. The 2-h BG levels in IGT during the first trimester were higher than in borderline (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Inducement of antibody that mimics insulin action on insulin receptor by insulin autoantibody directed at determinant at asparagine site on human insulin B chain

We previously showed that purified human IgG1 insulin autoantibody (IAA) from the serum of male patient T.H. with insulin autoimmune syndrome is directed at a determinant at the asparagine site on the human insulin B chain. An anti-idiotypic antibody (anti-TH) that inhibited TH-IAA binding to human insulin was obtained by immunizing BALB/c mice with TH-IAA. Anti-TH bound to viable IM-9 cells and the purified insulin receptor from IM-9 cells. Anti-TH binding to IM-9 cells and the insulin receptor was inhibited by TH-IAA but not by human IgG. Moreover, incubation of HepG2 cells with anti-TH had an inhibitory effect on insulin binding to HepG2 cells. Anti-TH, like insulin, stimulated amino acid uptake in HepG2 cells. These findings indicate that the conformation of TH-IAA idiotope is a mirror image of the determinant on the insulin B chain, the binding site for TH-IAA on anti-TH is also related to the insulin binding site on the insulin receptor, and anti-TH mimics insulin action on the insulin receptor.

Age of onset and type of Japanese younger diabetics in Tokyo

The age of onset of diabetes and the type of diabetes were examined in 1408 Japanese patients who were initially diagnosed as having diabetes under the age of 30 and were registered in our Diabetes Center between 1980 and 1989. Of the 1408 patients, 538 (38.2%) had insulin-dependent diabetes mellitus (IDDM) (male/female ratio of 2:3), and 870 (61.8%) had non-insulin-dependent diabetes mellitus (NIDDM) (male/female ratio of 5:4). There were significant differences of the sex ratio in both IDDM and NIDDM. The age at which the numbers in both the IDDM and NIDDM groups were almost equal was 13-14 (26 for IDDM and 23 for NIDDM at 13; 28 for IDDM and 30 for NIDDM at 14). A total of 58% of IDDM patients (22% of all patients) and only 6% of NIDDM patients (4% of all patients) were diagnosed under the age of 14 (P less than 0.01). Of the patients with IDDM, 42% (16% of all patients) were diagnosed over the age of 14, as were 94% of NIDDM (58% of all patients). The percentage of NIDDM cases increased even more over the age of 28, and no NIDDM patients developed diabetes under the age of 9.

The range of albumin concentrations in the single-void first morning urine of 1090 healthy young children

To predict microalbuminuria easily in the diabetic outpatient clinic, we determined the range of albumin concentrations in the single-void first morning urine in 1090 healthy subjects of age 6-11 by the modified turbidimetry immunoassay (TIA) method, which uses 96-well microplates and a microplate reader to perform the assay quickly and conveniently. As the correlation coefficient of albumin concentration by the TIA uncorrected for creatinine versus corrected for creatinine was r = 0.79 (P less than 0.005), the values uncorrected for creatinine were used. When the distribution of values from 1090 healthy young children was simulated by using the chi-square test (k = 1), the 95% confidence interval was 0-18 micrograms/ml.

Human monoclonal IgG1 insulin autoantibody from insulin autoimmune syndrome directed at determinant at asparagine site on insulin B-chain

Purified human insulin autoantibody (IAA) collected from the serum of a man (T.H.) with insulin autoimmune syndrome was characterized. The TH-IAA was found to be of IgG1 (lambda-light-chain) subclass. In addition to the single-binding affinity of TH-IAA to human insulin that we have shown in previous studies, the TH-IAA binding to human insulin was completely inhibited by a mouse monoclonal anti-idiotypic antibody against TH-IAA. A competitive inhibition study with various insulins revealed an epitope of human insulin against TH-IAA. These findings suggest that TH-IAA is monoclonal and is directed at a determinant at B-3 (asparagine) on the human insulin B-chain.

The immunoglobulin class, the subclass and the ratio of kappa:lambda light chain of autoantibodies to human insulin in insulin autoimmune syndrome

The immunoglobulin class, subclass and the k:lambda light chain ratio of insulin autoantibodies were determined in the sera of twenty-four patients with insulin autoimmune syndrome. All sera proved to be of the IgG immunoglobulin class but exhibited various IgG1:IgG2:IgG3:IgG4 ratios. The ratio of k:lambda light chain ranged from 1:0.13 to 1:0.75 with the exceptions of two sera that were characterized as IgG1(k) and IgG1(lambda).

Probing the human B-cell repertoire: isolation of Epstein-Barr virus (EBV)-transformed human B lymphocytes making antibodies with a common idiotope that have different antigen-binding specificities

Human peripheral B lymphocytes were transformed with Epstein-Barr virus and probed with an antiidiotypic antibody made against a human monoclonal autoantibody. Six cell lines were isolated that produced antibodies bearing a common idiotope. Despite the presence of this common idiotope, the antibodies showed antigen-binding specificities different from that of the parental antibody to which the antiidiotypic antibody was made. By probing Epstein-Barr virus-transformed cells with well-characterized antiidiotypic antibodies, it should now be possible to isolate and determine the frequency of B cells bearing specific idiotopes in the human repertoire and to study the antigen-binding properties of these antibodies.

Human monoclonal multiple-organ-reactive autoantibodies distinguished by mouse monoclonal anti-idiotypic antibodies: expression of idiotopes in humans with and without autoimmune diseases

Previously we reported on the production and characteristics of a number of human monoclonal autoantibodies. All of these autoantibodies were of the IgM class and reacted with antigens in multiple organs. In this study we generated IgG murine monoclonal anti-idiotypic antibodies against five human monoclonal autoantibodies, (i.e., MOR-h2, MOR-h3, MOR-h4, CG1, and CG2). These anti-idiotypic antibodies reacted strongly with the corresponding human monoclonal autoantibody, but minimally or not at all with other human monoclonal autoantibodies. By using these anti-idiotypic antibodies as probes, we screened sera obtained from normal individuals and patients with insulin-dependent diabetes mellitus, Hashimoto's thyroiditis, and systemic lupus erythematosus for the expression of idiotopes. Our study showed that the idiotopes recognized by three of the anti-idiotypic antibodies, i.e., anti-CG1, anti-CG2, and anti-MOR-h2, were not expressed, but the idiotopes recognized by two of the anti-idiotypic antibodies, i.e., anti-MOR-h3 and anti-MOR-h4, were expressed in normal individuals. In patients with autoimmune disorders, there was no increase in the expression of the CG1, CG2, and MOR-h2 idiotopes, but 45 and 23% of the patients with systemic lupus erythematosus showed a significant increase in the expression of the MOR-h3 and MOR-h4 idiotopes respectively. These findings show that there is widespread expression in the B cell repertoire of certain autoantibody-associated idiotopes.

Human monoclonal multiple-organ-reactive autoantibodies distinguished by mouse monoclonal anti-idiotypic antibodies: expression of idiotopes in humans with and without autoimmune diseases

Previously we reported on the production and characteristics of a number of human monoclonal autoantibodies. All of these autoantibodies were of the IgM class and reacted with antigens in multiple organs. In this study we generated IgG murine monoclonal anti-idiotypic antibodies against five human monoclonal autoantibodies, (i.e., MOR-h2, MOR-h3, MOR-h4, CG1, and CG2). These anti-idiotypic antibodies reacted strongly with the corresponding human monoclonal autoantibody, but minimally or not at all with other human monoclonal autoantibodies. By using these anti-idiotypic antibodies as probes, we screened sera obtained from normal individuals and patients with insulin-dependent diabetes mellitus, Hashimoto's thyroiditis, and systemic lupus erythematosus for the expression of idiotopes. Our study showed that the idiotopes recognized by three of the anti-idiotypic antibodies, i.e., anti-CG1, anti-CG2, and anti-MOR-h2, were not expressed, but the idiotopes recognized by two of the anti-idiotypic antibodies, i.e., anti-MOR-h3 and anti-MOR-h4, were expressed in normal individuals. In patients with autoimmune disorders, there was no increase in the expression of the CG1, CG2, and MOR-h2 idiotopes, but 45 and 23% of the patients with systemic lupus erythematosus showed a significant increase in the expression of the MOR-h3 and MOR-h4 idiotopes respectively. These findings show that there is widespread expression in the B cell repertoire of certain autoantibody-associated idiotopes.

Pancreatic islet cell surface glycoproteins containing Gal beta 1-4GlcNAc-R identified by a cytotoxic monoclonal autoantibody

To investigate the autoimmune pathogenesis of spontaneously occurring diabetes mellitus in BB rats, spleen cells of newly diagnosed diabetic BB rats were fused with mouse myeloma cells. Hybridoma supernatants were screened for antibodies by indirect immunofluorescence and by 51Cr-release assays using the RINm5F rat insulinoma cell line. One clone, E5C2, produced an IgM kappa antibody that was cytotoxic for RINm5F cells, but not for other rat cell lines nor for primary rat islet cells. However, treatment of primary rat islet cells with neuraminidase exposed surface antigens and rendered the cells susceptible to complement-mediated lysis by antibody E5C2. Using immunostaining of glycolipids separated by thin-layer chromatography, hapten inhibition assays with defined carbohydrates, and Western blots, the antigens recognized by E5C2 on RINm5F cells were identified as glycoproteins with molecular weights of 60,000 and 68,000. The antibody recognizes a carbohydrate antigen containing the sequence Gal beta 1-4GlcNAc-R, which on RINm5F cells is predominantly hidden by covalently bound sialic acid. These studies raise the possibility that hidden antigenic determinants on islet cells exposed by a variety of means may be the target of autoimmune attack.

Effect of poly(ADP-ribose) synthetase inhibitor administration to rats before and after injection of alloxan and streptozotocin on islet proinsulin synthesis

Nicotinamide (10 mmol/kg) and 3-aminobenzamide (1.25 mmol/kg), poly(ADP-ribose) synthetase inhibitors, were injected intravenously to rats either 30 min before the intravenous administration of 12 mg/kg alloxan or 50 mg/kg streptozotocin ("pretreatment") or 5 min after the administration ("posttreatment"). Fifteen minutes after the injection of the diabetogenic agents, pancreatic islets were isolated from the rats and proinsulin synthesis was determined. Proinsulin synthesis was decreased in islets from rats treated with alloxan or streptozotocin. Pretreatment with poly(ADP-ribose) synthetase inhibitors was found to protect against alloxan- or streptozotocin-induced decrease in proinsulin synthesis. By posttreatment with poly(ADP-ribose) synthetase inhibitors, streptozotocin-induced decrease in proinsulin synthesis was also significantly reversed, whereas the decrease induced by alloxan was not.

Protection by superoxide dismutase, catalase, and poly(ADP-ribose) synthetase inhibitors against alloxan- and streptozotocin-induced islet DNA strand breaks and against the inhibition of proinsulin synthesis

We have shown previously that alloxan and streptozotocin, two major diabetogenic agents, cause DNA strand breaks in rat pancreatic islets and stimulate nuclear poly(ADP-ribose) synthetase, thereby depleting intracellular NAD level and inhibiting proinsulin synthesis (Okamoto, H. (1981) Mol. Cell. Biochem. 37, 43-61; Yamamoto, H., Uchigata, Y., and Okamoto, H. (1981) Nature 294, 284-286). In the present study, superoxide dismutase and catalase, scavengers of radical oxygens, were found to protect against islet DNA strand breaks and inhibition of proinsulin synthesis induced by alloxan. The radical scavengers did not affect islet DNA strand breaks or inhibition of proinsulin synthesis induced by streptozotocin. On the other hand, compounds that inhibit islet nuclear poly(ADP-ribose) synthetase were found to protect against alloxan- as well as streptozotocin-induced inhibition of proinsulin synthesis. The poly(ADP-ribose) synthetase inhibitors were ineffective in protection against DNA strand breaks induced by the agents. These results may provide an important clue for elucidating the prevention of insulin-dependent diabetes as well as for understanding the cause of diabetes.

Maturation of renal and hepatic monodeiodination of thyroxine to triiodothyronine and post-natal changes of serum thyroid hormones in young rats

Maturational changes of renal and hepatic 5'-monodeiodination of thyroxine (T4) and post-natal changes of serum thyroid hormone levels were investigated in young rats under 35 days of age. Renal T3 generation in the 1-day-old rats was low, rose progressively to a level of more than 200% of the adult rats on days 21 and 28 and declined thereafter. In contrast, hepatic T3 generation increased from an initial low activity to a plateau after 7 days of age, which was 1 1/2 times higher than that of adult rats. Because of the extremely low value of serum T4 in the neonatal period, T3/T4 and rT3/T4 ratios were elevated on day 7. The ratio of rT3/T4 decreased gradually and became stable after 21 days of age, while the T3/T4 ratio increased reciprocally to a peak on days 21 and 28, corresponding to the period of maximal activity of renal T4 monodeiodination. These results indicate that in addition to elevated hepatic T4 monodeiodination, renal conversion of T4 to T3 may play a significant physiological role during the period of enhanced T3 requirement for maturation.

A syndrome of periodic adrenocorticotropin and vasopressin discharge

An 8-yr-old girl is presented who had periodic attacks of vomiting, psychotic depression, drowsiness, and hypertension (160/110 mm Hg) for a period of 16 months after head injury. At the initiation of the attack, serum ACTH and vasopressin levels were prominently increased (610 pg/ml and 41 microunits/ml, respectively), followed by hypercortisolemia, hyponatremia, and hypoosmolality in plasma. Serum PRL also was elevated (91 ng/ml). Responses of GH and cortisol to insulin-induced hypoglycemia and those of TSH to TRH were reduced. Urinary excretion of epinephrine and norepinephrine were increased, while dopamine (DA) excretion was reciprocally decreased, resulting in a marked elevation of the epinephrine plus norepinephrine to DA ratio during the episodes (0.4-4.5); this was normalized on attack-free days (0.08-0.25). During the attack, the concentration of homovanillic acid, a major metabolite of DA in the brain, also was reduced in cerebrospinal fluids from 70 to 23 ng/ml. The administration of methyl-dopa and reserpine effectively suppressed the recurrence of the episode. Although the exact cause of this syndrome is unknown, a periodic metabolic dysfunction of catecholamine in the central nervous system might be postulated.

Effect of human growth hormone on the distribution of amino acids between plasma and erythrocytes in pituitary dwarfism

To examine the effects of human growth hormone (hGH) on amino acid (AA) transport across the erythrocyte membrane, simultaneous determinations of 14 acidic and neutral AA concentrations in red cells and in plasma, and of gamma-glutamyltranspeptidase (GGTP) activity in red cell membrane were performed in 10 patients with pituitary dwarfism before and/or after hGH therapy. Blood samples were obtained at 0, 1, and 2 h after 4 IU of hGH injection. As AA concentrations in red cells showed wide fluctuations physiologically, samples from 5 normal children at the same intervals served as control. AA distribution was expressed as the concentration ratio of red cell to plasma (R/P). Aspartate and glutamate (group I AAs) showed great intracellular fluctuation concomitantly, which did not appear to be associated with hGH administration. R/P values of most of AAs were significantly decreased in untreated patients (P < 0.01–0.001 vs control), and changes after hGH were very small. In contrast, GH-treated patients exhibited large variance of changes in R/P of threonine, serine, glycine and alanine (group II AAs) at 2 h after hGH loading. However, R/P ratio of cystine, valine, methionine, isoleucine, leucine, tyrosine and phenylalanine (group III AAs) remained low or further depressed by hGH therapy. GGTP activity was also reduced in the untreated patients, while GH-treated patients revealed normal or supranormal GGTP activities. Between GGTP activity and integrated R/P of group II and III AAs, a statistically significant correlation was noted (r = 0.766, P < 0.001). These results suggest that physiologically a dynamic equilibrium exists between AAs in red cells and those in plasma, the transport system of which appears to be different in each group of AAs. hGH seems to exert promoting effects on the shift of AAs across the red cell membrane, at least in part by the activation of gammaglutamyl cycle.

Periodic ACTH discharge

A 9 1/2-year-old girl is presented who had cyclical attacks of abdominal pain, vomiting, emotional disturbance, and marked weight change for two years. Associated findings were facial plethora, hypertension, transient hyperglycemia and glycosuria, elevated plasma ACTH, cortisol, and urinary 17-OHCS excretion, and low plasma osmolality with hyponatremia. Urinary excretion of catecholamines and porphyrin metabolites was not increased. Between episodes, she showed no abnormal clinical signs or laboratory data. The attacks were effectively suppressed with the administration of chlorpromazine. The disorder appears to be due to the periodic release of excessive ACTH; the cause remains unknown.

Long-term effects of human growth hormone on plasma amino acids transport in hypopituitary dwarfism

The chronic effects of human growth hormone (hGH) on the transport of plasma amino acids (PAA) induced by glucose administration were studied in 17 patients with GH deficiency at different stages in the course of GH therapy. The study comprised 9 patients before and after 2–3 months of the therapy and 8 patients after prolonged treatment of 2–3 years. Five normal children served as controls. Analysis of 13 neutral and acidic PAA concentrations before and 2 h after glucose loading was carried out, and a decrease in PAA was expressed as a percentage of 2 h value to the initial level (PAA ratio). Fasting levels of several PAA before treatment were significantly lower than those of controls which gradually rose during the course of the therapy. The mean ± sd value of PAA ratio was also reduced before treatment (68 ± 16 %) vs. that of controls (82 ± 16 %, P < 0.05), which rose after 2–3 months of GH therapy to a comparable level of controls (91 ± 26 %). In patients treated for 2–3 years, however, PAA ratio was decreased to the level of pre-treatment (57 ± 17 %), P < 0.01 vs. control). These changes were pronounced in glucogenic, branched-chain and aromatic amino acids. Serum gamma-glutamyltranspeptidase (GGTP) activity was also low before GH therapy and normalized by the treatment. However, no significant correlation was noted between PAA ratio and serum GGTP activity or GH level. These results indicate that PAA transport evoked by endogenous insulin changes considerably according to the duration of GH therapy, and this may reflect a peripheral alteration of responsiveness to exogenous GH in the prolonged course of GH therapy in pituitary dwarfs.