Metabolic and ultrastructural effects of cyclosporin A on pancreatic islets

We investigated the effect of different doses of cyclosporin A (CyA) on glucose and insulin levels, as well as its residual effects on pancreatic islets ultrastructure after discontinuation of the drug. We studied four groups of Wistar rats. One control- (n = 5) and three experimental groups, n = 10 each, were treated with different doses of CyA i.m. for 14 days: group I, 5 mg/Kg; group II, 15 mg/Kg; and group III, 25 mg/Kg. Five animals of each group were sacrificed after 14 days, and the remaining five after 21 days to assess residual CyA effects. On the day of sacrifice, the rats underwent maltose absorption test, and glucose and insulin levels were measured. Pancreatic biopsies were obtained on day 21 to evaluate islets ultrastructure by electron microscopy. As a result, statistically significant, dose dependent (P < 0.05) increases in glucose and insulin levels were observed in CyA-treated groups. Groups II and III showed insulin levels significantly higher after fasting (P < 0.05) on day 14 comparing to the controls, while in groups I and II values returned to normal after CyA discontinuation. Group III showed persistently increased insulin levels on day 21. Pancreatic ultrastructural changes were observed only in group III. We can conclude that CyA effects on glucose and insulin levels were temporary and reversible at low doses. Ultrastructural changes in the pancreatic islets may occur with high doses of CyA.

Microangiopathic complications in type 1 diabetes mellitus: differences in severity when isolated or associated with autoimmune polyendocrinopathies

CONTEXT

The development and evolution of different chronic diabetic complications may present variations among the different types and conditions of this disease.

OBJECTIVE

To evaluate the degree of microangiopathy in Type 1 diabetes mellitus (DM1) associated with autoimmune polyendocrinopathies (OSAD) or isolated DM1 (iDM1).

PATIENTS

OSAD (n = 17) and iDM1 (n = 13) were over 15 years old at diagnosis of DM and were matched for diabetes duration (13.9 +/- 8.2 and 13.2 +/- 5.9 years respectively) and metabolic control (HbA1c: 6.4 +/- 1.9 and 6.8 +/- 1.4%).

MAIN OUTCOME MEASURES

Urinary albumin excretion (UAE; ELISA), the inversion of serum creatinine (1/C) level and indirect ophthalmoscopy.

RESULTS

Although the prevalence of hypertension was similar in both groups, the OSAD had inferior levels of UAE (7.4 +/- 2.5 vs. 17.3 +/- 9.2 micrograms/min; p < 0.05). Nephropathy was detected in 12% of the OSAD (none of them macroproteinuric) and in 39% of the iDM1. The UAE in the iDM1 correlated negatively with 1/C values (r = -0.7, p < 0.005), but the same did not occur in the OSAD (r = 0.2, ns). Among patients with retinopathy, the severe form was found in 29% of the OSAD and in 46% of the iDM1.

CONCLUSIONS

OSAD was associated with a lower degree of microangiopathy, in spite of age at diagnosis, duration of diabetes and the metabolic control. In contrast with the iDM1, the increase in UAE of OSAD was not associated with reductions in GFR.

Detection of adrenocortical autoantibodies in Addison's disease with a peroxidase-labelled protein A technique

Adrenocortical autoantibodies (ACA), present in 60-80% of patients with idiopathic Addison's disease, are conventionally detected by indirect immunofluorescence (IIF) on frozen sections of adrenal glands. The large-scale use of IIF is limited in part by the need for a fluorescence microscope and the fact that histological sections cannot be stored for long periods of time. To circumvent these restrictions we developed a novel peroxidase-labelled protein A (PLPA) technique for the detection of ACA in patients with Addison's disease and compared the results with those obtained with the classical IIF assay. We studied serum samples from 90 healthy control subjects and 22 patients with Addison's disease, who had been clinically classified into two groups: idiopathic (N = 13) and granulomatous (N = 9). ACA-PLPA were detected in 10/22 (45%) patients: 9/13 (69%) with the idiopathic form and 1/9 (11%) with the granulomatous form, whereas ACA-IIF were detected in 11/22 patients (50%): 10/13 (77%) with the idiopathic form and 1/9 (11%) with the granulomatous form. Twelve of the 13 idiopathic addisonians (92%) were positive for either ACA-PLPA or ACA-IIF, but only 7 were positive by both methods. In contrast, none of 90 healthy subjects was found to be positive for ACA. Thus, our study shows that the PLPA-based technique is useful, has technical advantages over the IIF method (by not requiring the use of a fluorescence microscope and by permitting section storage for long periods of time). However, since it is only 60% concordant with the ACA-IIF method, it should be considered complementary instead of an alternative method to IIF for the detection of ACA in human sera.

Prospective bone mineral density evaluation in patients with insulin-dependent diabetes mellitus

The bone mineral density (BMD) in patients with insulin-dependent diabetes mellitus (IDDM) was evaluated prospectively to assess the course of osteopenia in IDDM. We measured BMD in the lumbar spine, femoral region, and total body calcium in 23 patients aged 21-53 years with IDDM for 2.3 to 20 years using a dual energy X-ray absorptiometry. A second BMD measurement was done after 26.5+/-4.1 months in all patients. The blood glucose control, insulin dosage, and disease duration were also assessed. Eleven patients had osteopenia (1 Z-score below the mean values of normal gender- and age-matched individuals). These patients had a longer IDDM duration (8.6+/-5.1 years in osteopenics versus 4.6+/-3.75 years in non-osteopenics; p=0.03). The blood glucose control and insulin dosage were not significantly different throughout the study. The mean spinal BMD was higher in the second evaluation in both osteopenics (0.91+/-0.12 g/cm2 and 0.96+/-0.09 g/cm2, p=0.035) and non-osteopenics (1.24+/-0.15 g/cm2 and 1.29+/-0.16 g/cm2; p=0.02). In the end of the study, however, the osteopenic group persisted with lower subnormal BMD values than the non-osteopenic group (p < 0.001). The small BMD increment observed in the spine did not correlate with changes in the metabolic control or with IDDM duration, but occurred mainly in patients younger than 30 years old. There was no significant change in the femoral BMD or total body calcium. None of the patients developed or significantly worsened the osteopenia. We conclude that diabetic osteopenia, despite being a complication of high prevalence in IDDM, seems to be non-progressive in the majority of patients. In some patients, the spinal BMD increased during observation and may have been due to achievement of peak bone mass.

Vitamin D receptor gene polymorphism: correlation with bone mineral density in a Brazilian population with insulin-dependent diabetes mellitus

Patients with insulin-dependent diabetes mellitus (IDDM) are at higher risk of developing osteoporosis. Among the genetic factors related to the development of osteoporosis, a possible association between vitamin D receptor (VDR) gene polymorphism and bone mineral density (BMD) has been described in some populations. We characterized the VDR gene polymorphism in a healthy adult Brazilian population and in a group of patients with IDDM and correlated these findings with densitometric values in both groups. The Brazilian population is characterized by an important racial heterogeneity and therefore is considered an ethnically heterogeneous population. We recruited 94 healthy adult Brazilian volunteers (63 women and 31 men), mean (+/- SD) age 32.4 +/- 6.5 years (range 18-49 years), and 78 patients with IDDM (33 women and 45 men) diagnosed before 18 years of age, mean (+/- SD) age 23.3 +/- 5.5 years (range 18-39 years). VDR genotype was assessed by polymerase chain reaction amplification followed by BsmI digestion on DNA isolated from peripheral blood leukocytes. Statistical analysis included Bonferroni t-test to compare densitometric values within different genotypes in both groups and multiple regression analysis of bone density adjusted for potential confounding factors. The IDDM group had a lower BMD compared with the control group. The VDR genotype distribution in the control group was 43 Bb (45.7%), 39 bb (41.5%) and 12 BB (12.8%). This distribution did not differ from that observed in the IDDM group: 39 Bb (50%), 26 bb (33.3%) and 13 BB (16.7%). In the IDDM group, patients with the Bb genotype had a higher body weight when compared with the BB genotype (p = 0.02). However, when diabetic patients were controlled for age, sex and body mass index, BB genotype was associated with a lower mean BMD at lumbar spine and femoral neck than in Bb and bb patients. BB patients had a shorter duration of IDDM than bb and Bb patients. These findings suggest a small influence of VDR gene polymorphism on BMD of a racially heterogeneous population with IDDM.

Acute renal failure due to rhabdomyolysis in diabetic patients

We report a 32-year-old Black man, admitted to the ICU with coma and severe metabolic disturbances due to diabetic ketoacidosis. During the admission, rhabdomyolysis and acute renal failure (ARF) were diagnosed. After metabolic control and gradual decrease of creatine kinase levels, he presented a progressive improvement of renal function. We emphasize nontraumatic rhabdomyolysis as a poorly recognized pathogenetic factor for ARF in diabetic ketoacidosis and suggest that a better understanding of its mechanisms and an early application of protective measures is necessary.

[Diabetic ketoacidosis induced by immunologic insulin resistance]

Although rare, ketoacidosis may be induced by the occurrence of antibody mediated insulin resistance. Cases of 3 patients with ketoacidosis precipitated by immunologic insulin resistance (IIR) are reported. CASE REPORT--Three patients were admitted to the primary care unit of Hospital São Paulo in Diabetic Ketoacidosis. Demographic data of the patients (HML, DRJ and DIS) included: age (46.39 and 54 y.o.); sex (2F, 1M); diabetes mellitus (2 DM II and 1 pancreatic); duration of diabetes (6, 11 and 9 years) and BMI (17.5; 25.5 and 24.3 kg/m2. Admission laboratory data were: glucose (40, 38 and 22 mmol/L); pH (7.2; 6.9 and 7.2) and all had ketonuria. Insulin requirements for metabolic control were: HML: 1494U; DRJ: 1496U; DIS: 450U in a period of: 212, 206 and 72h. The plasmatic leves of Anti insulin antibodies (IA) measured by RIA (nU/mL) and ELISA (EI), where: HML: 7186, 3.26; DRJ: 7879, 3.42 and DIS: 8377, 2.88. HI was associated with marked decrease of both, insulin requirements and IA (HML: 3393, 1.39 after 10 months and DRJ: 4673, 2.34; DIS: 1510, after 18 months) at follow-up. DISCUSSION--The High Insulin requirements and time necessary to achieve the metabolic control guided us to the diagnosis of IIR. It was confirmed by high levels of AI and by the improvement in the metabolic control after the introduction of HI. CONCLUSION--The physician must be alert to severe IIR if there is no response after standard therapy to ketoacidosis. HI can be considered a valid alternative of treatment for IIR.

Detection of insulin antibodies by radioassay and ELISA: interrelation and correlation with metabolic control in type I diabetes

1. The literature suggests that the radioassay (RA) and ELISA detect different types of insulin antibodies (IA) (Wilkin et al., 1989. Diabetes, 38: 172-181). 2. In the present study we evaluated the relationship between these two antibodies and their involvement in the metabolic control of Type I diabetic (DMI) patients. 3. IA were measured by RA and ELISA in sera obtained from 34 patients (age: 9-16 years, median = 12.5 years; clinical duration of DMI: 0.1-11.0 years, median = 1.7 years) treated with different types of insulin [purified (bovine + porcine) N = 18, and monocomponent (porcine or human) N = 16] and submitted to various degrees of metabolic control as assessed by glycosylated serum protein (GSP) levels: range, 3.4-13.5%; median = 8.7%; normal value, 0.8-2.4%. 4. Insulin antibody levels measured by RA were: 3264 +/- 300 nU/ml (mean +/- SEM, normal value < 60 nU/ml) and by ELISA: 0.74 +/- 0.11 ELISA index (EI) (normal value, < 0.53). No correlation was found between IA levels measured by RA and ELISA, or between duration of the disease or insulin daily necessity and IA by either method. GSP was positively correlated with IA determined by ELISA (rS = 0.43, P < 0.01) but not with IA determined by RA. 5. The patients on purified bovine + porcine insulin had higher titers of IA by ELISA, compared to those of patients on monocomponent (0.96 +/- 0.15 vs 0.50 +/- 0.13 EI, P < 0.03, while IA levels measured by RA did not differ between groups. 6. These data show that RA or ELISA assays provide different serum titers of IA in insulin-treated diabetics and data obtained with ELISA correlated best with the metabolic control of Type I diabetic patients.

Prevalence and magnitude of osteopenia associated with insulin-dependent diabetes mellitus

The authors evaluated the prevalence, magnitude, and contributing factors for osteopenia in insulin-dependent diabetes mellitus (IDDM). We measured bone mineral density (BMD) in the lumbar spine and femoral region in 90 patients aged 18-54 years with IDDM using dual-energy x-ray absorptiometry. The blood-glucose control, insulin dosage, duration of disease, and presence of chronic complications of diabetes were evaluated. Serum ionized calcium, magnesium, phosphorus, alkaline phosphatase (ALP), 25-hydroxycholecalciferol, immunoreactive parathyroid hormone (iPTH), and urinary calcium, phosphorus, and hydroxyproline were also analyzed. Thirty-one patients (34%) were classified as having a reduced BMD (less than 2 SD below the mean). The comparison between normal and low BMD patients showed that the osteopenics had a tendency to be younger (median, 28 years versus 32 years), showed a higher mean plasma glucose (15.5 +/- 5.0 mmol/L versus 12.9 +/- 3.8 mmol/L; p = 0.018), longer duration of disease (11.2 +/- 2.1 years versus 5.0 +/- 1.3 years; p = 0.004), and needed a higher insulin dosage (56 +/- 17 U/day versus 43 +/- 16 U/day; p < 0.001). There was a positive correlation between mean glucose levels, duration of disease, insulin dosage, and bone-mass decrease. A higher incidence of chronic complications, mainly retinopathy (58% versus 25%) and neuropathy (52% versus 22%) was found in the low BMD group. There was no alteration of serum calcium, phosphorus, iPTH, 25-hydroxycholecalciferol, and urinary calcium and phosphorus. The ALP levels were significantly higher in the osteopenic group, and magnesium and hydroxyproline levels were lower in the whole diabetic group, but these measurements did not correlate with BMD reduction.(ABSTRACT TRUNCATED AT 250 WORDS)

[The non-insulin-dependent phase of type I diabetes mellitus]

Case report on a child whose type I diabetes mellitus was diagnosed 23 months before the appearance of overt glucose intolerance. In this pre-IDDM stage of DMI were observed secondary enuresis, decreased growth speed, transient hyperglycemia and asymptomatic glycosuria. These alterations may represent the earliest clinical manifestation of impaired beta cell function. Immunologic markers (ICA and/or AAI) of DMI and abnormalities of the first-phase insulin secretion in response to intravenous glucose also may precede by several months the most common clinical picture of type I diabetes as they were detected in this child. If possible, markers and alterations should be tested in such patients and their young relatives with DMI in order to detect high risk individuals who may develop DMI. Such and accurate predictive ability should be a prerequisite to institution of appropriate therapy to preventing further beta cell destruction and severe metabolic decompensation, thus having the potential to reduce morbidity and mortality from new onset DMI.

[Diabetic ketoacidosis in a Krenak Indian]

The authors present a case of spontaneous ketoacidosis developed by one 32 years Krenak indian. The patient denied alcoholism and his mother had Type II diabetes for the last 3 years. The search to islets and insulin autoantibodies was negative in this patient. The basal C-peptide was found normal during follow-up. The patient received a short insulin therapy and now he shows good metabolic control (normal glycosylated hemoglobin) with oral hypoglycemic treatment. The environment influence, indian customs and the rarity of spontaneous ketoacidosis in these individuals were reviewed and discussed.

Premature menopause: monoclonal antibody defined T lymphocyte abnormalities and antiovarian antibodies

The presence of other organ-specific autoimmune disorders in some patients with premature menopause has supported the concept of an autoimmune etiology. The authors analyzed the peripheral blood of 23 women with the diagnosis of premature menopause to detect the presence of monoclonal antibody-defined T-lymphocyte abnormalities and/or antiovarian antibodies. All subjects were less than 40 years of age with the duration of menopause ranging from less than 1 year to 11 years at the time of study. Thirty-five percent of the subjects had an elevated percentage of Ia+ (Dr-activated) T cells using monoclonal antibody L243. The percent T4 (helper) T8 (suppressor/cytotoxic) T cells and T4/T8 ratio were normal in the study group. Four subjects (approximately 17%) had elevated percentages of the age-related 3G5+ T cell subset. Two of the subjects with increased 3G5+ T cells also exhibited increased Ia+ T cells. Antiovarian steroid cell antibodies and antiadrenal cortical antibodies were present in approximately 9% of subjects. Anti-islet cell antibodies were not present. Thyroid antimicrosomal antibodies were present in 17% of subjects. Study subjects exhibited immunologic abnormalities that the authors hypothesize may play a role in the development of premature menopause in a larger percentage of patients than was previously suspected.

Circulating anti-immunoglobulin antibodies in recent-onset type I diabetic patients

Human sera from 51 recent-onset insulin-dependent (type I) diabetic patients and 47 unrelated control subjects were screened for the possible presence of circulating factors reacting with several anti-pancreatic islet monoclonal antibodies (MoAb.ISL) in solid-phase radioimmunoassay methods (the original goal being the detection of anti-idiotypic islet cell antibodies and/or specific islet cell antigen-bearing immune complexes). MoAbs from the parental myeloma cell line and purified immunoglobulins (Igs) from different animal species were controls. Type I diabetic sera showed significantly increased binding to MoAb.ISL-coated wells compared with normal subjects (P less than .001). However, the same sera also tended to show a higher binding to the control (non-islet-related) MoAb. Sera from type I diabetic patients also reacted with horse, bovine, pig, rabbit, and goat IgG. Displacement of the binding has been obtained by F(ab')2 and/or Fc fragments of IgG. Evidence has been obtained regarding a similar reaction with human IgM. All the sera were negative when tested for rheumatoid factor by nephelometry. The circulating antibodies described have been proven to be different from islet cell autoantibodies. An anti-Ig antibody is thus present in the sera of recent-onset diabetic patients and represents an additional immunological phenomenon with possible physiopathological and clinical significance.

A novel neuroendocrine cell surface glycoprotein: identification, isolation, and initial characterization

Murine monoclonal antibodies (MAbs) HISL-5, -9, and -14, generated after immunization of mice with human pancreatic islet cell preparations, recognize a differentiation antigen expressed by the pancreatic islet cells. These MAbs react strongly with all endocrine cell subtypes of human pancreatic islets, but minimally if at all with the exocrine acinar cells, vascular cells, and stromal connective tissue cells of the pancreas. The antigen is located on the cell surface (plasma membranes), as indicated by immunofluorescence staining of viable cell preparations. Besides the pancreatic islets, HISL-5, -9, and -14 antigenic determinants are also expressed by thyroid follicular cells, parathyroid chief cells, and anterior pituitary cells, other commonly involved targets in organ-specific autoimmune disorders. Preliminary biochemical findings indicated that the MAb-defined epitope(s) is trypsin sensitive and resistant to periodate oxidation and exposure to chloroform-methanol. Further biochemical studies, including single step MAb immunoaffinity chromatographic purification, indicate that the antigen recognized by the MAbs HISL-5, -9, and -14 is a 100 K glycoprotein.

Selective localization of factor VIII antigenicity to islet endothelial cells and expression of class II antigens by normal human pancreatic ductal epithelium

We evaluated the expression of factor VIII and class II histocompatibility antigens on frozen sections of normal human and rat pancreases. The immunohistologic studies were performed with directly fluoresceinated anti-human factor VIII and monoclonal antibodies A2B5, 3G5 (anti-islet), L-243, I-2, OK1 (anti-human Ia-DR), Leu-10 (anti-human HLA-DQ), anti-human HLA-DP, and OX6 (anti-rat Ia). Islet endothelial cells of humans and Wistar, CD, and BB diabetes-prone rats could be distinguished from intra-acinar endothelial cells by markedly enhanced factor VIII immunoreactivity. Factor VIII-antibody staining of islet endothelial cells was specifically absorbed by prior incubation of anti-human factor VIII antibody with normal human plasma but not by incubation with factor VIII-deficient plasma. By double indirect immunofluorescence, normal human pancreatic ductal epithelium expressed Ia in five of six pancreases studied.

Competitive insulin autoantibody assay. Prospective evaluation of subjects at high risk for development of type I diabetes mellitus

A quantitative fluid-phase radioassay for autoantibodies reacting with insulin (competitive insulin autoantibody assay, CIAA) was developed. The assay's features include 1) use of a physiologic amount of 125I-labeled insulin, 2) parallel incubations with supraphysiologic cold insulin (competitive), and 3) an incubation time of 7 days and a single-step multiple-wash polyethylene glycol separation. Mean +/- SE CIAA levels in 50 controls were 8 +/- 1.4 nU/ml (range -16-33.3). In 36 cytoplasmic islet cell antibody (ICA)-positive nondiabetic first-degree relatives of type I (insulin-dependent) patients less than 30 yr of age, CIAA levels exceeded the normal range in 20 (55.6%) of 36 (mean 86.8 +/- 17.1 nU/ml). In 26 ICA-positive relatives greater than 30 yr of age, only 5 (19.2%) of 26 exceeded the normal range (mean 26.1 +/- 9.4 nU/ml); P less than .001 compared with younger ICA-positive relatives). Six ICA-negative HLA-identical siblings of type I diabetic patients had normal CIAA levels (mean 3.6 +/- 5.8 nU/ml), and only 2 of 13 ICA-negative identical twins discordant for diabetes (mean 15.4 +/- 6.6 nU/ml) exceeded the normal range. Nine (50%) of 18 ICA-positive schoolchildren exceeded the normal range (mean 105.3 +/- 36.7 nU/ml). Genetically susceptible subjects negative for CIAA (with only 3 exceptions) remained negative for CIAA on multiple determinations (3 conversions observed), and CIAA levels of positive subjects were relatively stable. Linear regression of the first CIAA level versus last (interval between sampling 1 mo to 10 yr) in genetically susceptible individuals showed a highly significant correlation (r = .95, P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of cytoplasmic islet cell antigens by rat pancreas

A major problem in standardization of the islet cell cytoplasmic antibody (ICA) assay is variation in sensitivity of the different human pancreas substrates used in individual laboratories. To circumvent this problem, we have developed an assay that utilizes Wistar-Furth rat pancreas as substrate, an anti-islet monoclonal antibody (A2B5) to identify islets and fluorescein-conjugated protein A to identify patient autoantibodies. Sera from 85 control subjects, 27 type I diabetics, and 17 subjects at high risk for developing type I diabetes were assayed in parallel with our standard ICA assay on human pancreas substrate and with Wistar-Furth rat pancreas as substrate. Two sera from control subjects (2 of 85) were ICA positive with rat pancreas compared to 1 of 85 with human pancreas substrate. Sera from 11 of 27 type I diabetics and 15 of 17 sera from high-risk subjects were ICA positive with either rat or human pancreas substrate. A correlation between the specific islet fluorescence readings on human and rat pancreas sections was found with sera from high-risk and control subjects. Furthermore, end-point titers of an ICA-positive serum were identical with both assays. Finally, incubation of an ICA-positive serum with glycolipids, extracted from either human or Wistar-Furth rat pancreas, blocked subsequent ICA binding. These findings suggest that Wistar-Furth rat pancreas expresses an identical or similar autoantigen to human pancreas.

Hemiagenesis of the thyroid gland and T3 hyperthyroidism

A patient with hemiagenesis of the thyroid gland who presented with T₃ toxicosis is described. The diagnosis of thyroidal hemiagenesis was established through the administration of thyroid stimulating hormone and a thyroid scintiscan.

T₃ thyrotoxicosis is a previously unreported clinical presentation of thyroid hemiagenesis.