Glucose and insulin responses to oral glucose in overt non-insulin-dependent diabetics with and without the islet cell antibody.

Plasma insulin, glucose, and insulin/glucose responses to a 50-g oral glucose tolerance test (OGTT) were compared in 14 islet cell antibody (ICAb) positive non-insulin-dependent diabetics (NIDDM), 14 matched ICAb negative NIDDM, and 14 ICAb negative nondiabetic controls. Both groups of NIDDM exhibited marked carbohydrate intolerance with insulinopenia. Despite having significantly higher plasma glucose concentrations during the study, the ICAb positive NIDDM had significantly lower insulin levels, and thus lower insulin/glucose ratios, than the ICAb negative NIDDM both in the fasting state and in response to the OGTT. Similarily, ICAb positive NIDDM had higher integrated glucose responses (delta G), lower integrated insulin responses (delta I), and lower delta I/delta G values than ICAb negative NIDDM. Three ICAb negative and seven ICAb positive NIDDM subsequently required insulin treatment. These findings show that ICAb positive NIDDM suffer from a greater disturbance of B-cell function than do matched ICAb negative NIDDM.

Cell-mediated immunity in diabetes mellitus; lymphocyte transformation by insulin and insulin fragments in insulin-treated and newly-diagnosed diabetes.

Using a radioisotope labeling technic, the ability of bovine and porcine insulin antigens to induce lymphocyte transformation was tested with cells from the peripheral blood of thirty nondiabetic controls, fifty established insulin-dependent diabetics with no evidence of insulin allergy, and ten newly diagnosed diabetics (five untreated, five insulin-treated for less than three weeks). Lymphocytes from twenty-six (42 per cent) of the diabetics showed significant blastogenesis to bovine or porcine insulin, as compared with two (7 per cent) of controls; the phenomenon was shown by both established and newly diagnosed patients including four who had never recieved insulin. The results indicate that cellular hypersensitivity to insulin, as judged by an in vitro test, is relatively common in insulin-treated diabetics without in vivo evidence of allergy, and suggest that hypersensitivity may also be present in untreated diabetics. Lymphocytes from twenty-one of the twenty-six diabetics who responded to intact insulin were further tested using bovine and porcine insulin A chain bovine B chain as antigens. The A chain of either insulin induced significant blastogenesis in only one diabetic but bovine B chain induced significant blastogenesis in fourteen (67 per cent) of the patients tested. These results suggest that B chain is the major antigenic site determining cellular hypersensitivity to insulin. Diabetes 24:36-43, January, 1975.

Pancreatic islet-cell antibodies in diabetes mellitus correlated with the duration and type of diabetes, coexistent autoimmune disease, and HLA type.

In a study of 972 patients with diabetes mellitus, humoral pancreatic islet-cell antibodies (I.C.Ab.) were detected in highest prevalence in insulin-treated diabetics with (38 per cent) and without (22 per cent) associated overt organ-specific autoimmune disease (A.I.D.) where consideration was not given to the duration of diabetes. They were also detected in 8 per cent of diabetics treated with oral hypoglycemic agents (O.H.A.), but not in diabetics requiring diet alone and in only 0.5 per cent of 434 control subjects. Six per cent of 522 patients with overt organ-specific A.I.D. but not diagnosed to be diabetic had I.C.Ab.s. I.C.Ab.s were present in the sera of 2 per cent of 157 first-degree relatives of I.C.Ab.-positive subjects. In insulin-treated diabetics and, to a lesser extent, in diabetics not requiring insulin, the prevalence of humoral I.C.Ab. was strongly dependent of the duration of the diabetes, being 60 per cent during the first year from diagnosis in the insulin-treated group and falling to 20 per cent at two to five years and to 5 per cent at 10-20 years. The prevalence of I.C.Ab. in insulin-treated diabetics showed no correlation with the patient's age at the time of testing when the duration of diabetes was taken into account. Diabetics who did not require insulin for treatment but who were I.C.Ab.-positive showed a significant tendency to subsequently require insulin and to have a higher prevalence of other autoantibodies than insulin-independent diabetics who were I.C.Ab.-negative. Persistence of I.C.Ab. for more than five years from diagnosis of diabetes was associated with coexistent overt organ-specific A.I.D. and with HLA-B8, A1, and A1 + B8.

The lack of specificity of ophthalmic immunoglobulins in Graves' disease.

Immunoglobulins (Igs) binding to retro-orbital muscle (ROM) antigens, known as ophthalmic Igs (OIg), were measured using a 100,000 X g sediment of porcine ROM as antigen in a solid phase [125I]protein A binding assay. Serum samples from 50 control subjects bound from 0.60-2.42 times the amount of [125I]protein A as did the normal reference serum samples, defined as the OIg ratio. Serum from 95 patients with hyperthyroid Graves' disease had OIg ratios from 0.64-9.99, with 24 (25%) being positive [OIg ratio greater than 2.05 (mean + 2 SD of the normal group)]. Ten patients with euthyroid Graves' ophthalmopathy had OIg ratios from 1.01-6.33, with 6 (60%) being positive. Among those Graves' disease patients with ophthalmopathy (n = 19) and the euthyroid Graves' ophthalmopathy patients there was a good correlation between the severity of eye signs and the OIg ratio. The OIg-positive serum samples cross-reacted with skeletal muscle and thyroid as well as with ROM antigen. This lack of specificity contradicts previous reports, but does not rule out a role for these antibodies in the etiology of Graves' ophthalmopathy.

A comparison of plasma TSH levels in patients with diffuse and nodular non-toxic goiter.

Plasma TSH levels were measured in 115 euthyroid patients with simple goiter, of whom 52 had diffuse and 63 nodular enlargement of the thyroid gland, and in 191 euthyroid patients without goiter. There was no significant difference between the plasma TSH levels in the patients with diffuse goiter and the non-goitrous controls, implying that the maintenance of diffuse hyperplasia is not dependent upon a raised level of plasma TSH. On the other hand, plasma TSH levels in the patients with nodular goiter were significantly lower than those recorded in either the patients with diffuse goiter (P less than 0.01) or in the patients without goiter (P less than 0.0001), supporting the view that thyroid function may be autonomous in nodular goiters.

Transient hypothyroidism after iodine-131 treatment of thyrotoxicosis.

Thirty consecutive patients with thyrotoxicosis were followed up at monthly intervals for 6 months after treatment with iodine-131. Serum total T4, serum total T3, and serum TSH response to TRH were measured at each review. Biochemical evidence of hypothyroidism (low T4 raised basal TSH) developed in 18 patients 1-4 months after treatment. In 5 of these patients, symptoms and signs of hypothyroidism remained absent or minimal and spontaneous recovery of thyroid function occurred during the ensuing 2 months. If biochemical hypothyroidism occurs during the first 6 months after radioiodine therapy, it is recommended that T4 replacement be withheld for 2 months unless the severity of symptoms demands treatment.

Propranolol in the treatment of thyrotoxicosis by subtotal thyroidectomy.

Subtotal thyroidectomy was performed in 40 patients with thyrotoxicosis in whom propranolol alone was used as preparation for surgery. Propranolol was given orally in a dose of 40 mg every 6 h for a mean preoperative period of 17 days (range 4-60 days) and continued for seven days after operation. The mean +/- SE blood loss at operation was only 160 +/- 20 ml. The period of follow-up was from three to nine months. Recurrent thyrotoxicosis has not occurred in any patient. Low levels of total serum triiodothyronine (T3) and total serum thyroxine (T4) were observed in the early postoperative weeks in some patients and were associated with symptoms of mild hypothyroidism, but by six months in the presence of a raised serum thyrotropin (TSH) the thyroid hormone levels returned to normal. Permanent hypothyroidism developed in only two patients. Despite normal or low total serum T3 and T4 levels, the TSH response to thyrotropin-releasing hormone (TRH) was absent in all patients one week after operation. At four weeks and at eight weeks, the response was absent or sub-normal in 70% and 20% of the patients respectively, indicating a delay in the recovery of the hypothalamo-pituitary axis previously exposed to high levels of T3 and T4. It is considered that subtotal thyroidectomy for thyrotoxicosis in patients prepared with propranolol is an acceptable procedure which has some advantages over the conventional preparation with carbimazole and potassium iodide, not the least of which are the potential reduction in preparation time, the more flexible timing of operation, and the reduced operative blood loss.

Progressive adrenal failure in polyglandular autoimmune disease.

We describe the clinical course of a boy who developed progressive adrenal failure, beginning with failure of the zona glomerulosa, as part of polyglandular autoimmune disease. Initially the patient presented with hypoparathyroidism and mucocutaneous candidiasis. ACTH tests at ages 8 and 11 yr resulted in a normal response of both mineralo- and glucocorticoids. The constellation of hyponatremia , hyperkalemia, and growth failure at age 14 yr prompted a reevaluation. A repeat ACTH test, assessing individual contributions of zone fasciculata and glomerulosa, showed normal plasma cortisol, desoxycorticosterone, and corticosterone responses and a normal urinary response of 18-hydroxydeoxycorticosterone and tetrahydrodeoxycorticosterone. Urinary 18-hydroxycorticosterone and urinary as well as plasma aldosterone were undetectable. PRA was markedly elevated. The ACTH response of adrenal androgens, presumably metabolic products of the zona reticularis, was also deficient. Antiadrenal antibodies against all three layers of the adrenal cortex were present. Mineralocorticoid therapy resulted not only in normalization of electrolytes and PRA but also in catch-up growth. Repeat testing of fasciculata function at age 19 yr now shows that the patient's cortisol response to ACTH response in abnormal. The course of this patient suggest that in addition to monitoring the electrolyte status, periodic tests for both mineralo- and glucocorticoid synthesis should be performed in children with polyglandular autoimmune disease because progressive adrenal insufficiency may go unrecognized.

Influence of thyroid status on dopaminergic inhibition of thyrotropin and prolactin secretion: evidence for an additional feedback mechanism in the control of thyroid hormone secretion.

Serum TSH and PRL concentrations were measured after the randomized oral administration of either metoclopramide, L-dopa, or placebo on 3 consecutive days to five patients with overt primary hypothyroidism (low serum total T4 and raised serum TSH) and to five patients with subclinical hypothyroidism (normal serum total T4 and raised serum TSH). In both groups there was a rise in serum TSH and PRL concentrations after metoclopramide and a fall after L-dopa when compared with the effect of the placebo. However, the rise in serum TSH and PRL concentrations was significantly greater in patients with subclinical hypothyroidism compared to that in patients with overt hypothyroidism. It was not possible to show any significant difference in the degree of fall of these pituitary hormones after L-dopa administration in the two groups. These results suggest that in addition to the established negative feedback of thyroid hormones at the level of anterior pituitary thyrotropes, there is a previously unrecognized effect of thyroid hormones at the hypothalamus, resulting in increased dopaminergic inhibition of TSH release. Stimulation of hypothalamic dopamine by thyroid hormones also inhibits PRL secretion.

Measurement of circulating immune complexes by radioimmunoassay of immunoglobulin in high molecular weight fractions.

A method for detecting circulating immune complexes is described based on radioimmunoassay of IgG following the rapid separation of immune complexes from monomeric IgG on short columns of Sephacryl S-300. Values obtained using sera from patients with immune complex associated diseases were distinctly higher than those obtained with sera from healthy control subjects. The same serum samples were assayed by 3 other methods for detecting immune complexes; significant correlation was obtained.

A search for heterogeneity in insulin dependent diabetes mellitus (IDDM): HLA and autoimmune studies in simplex, multiplex and multigenerational families.

HLA antigens (A, B, C and DR loci), serum islet cell antibodies, thyrogastric antibodies, and insulin antibodies were studied in 77 families (25 simplex, 42 multiplex, and 10 multigenerational). In order to test for intrafamilial constancy and intergroup variation, we compared simplex with multiplex families, HLA identical and non identical siblings within families, as well as groups of families characterized by different DR alleles (DR3, DR4, and DR3/DR4) for various immunologic and clinical characteristics. These comparisons did not reveal all the distinct subgroups suggested by different cross-sectional population studies, but did provide evidence for a compound form having an aggregation of different high risk alleles. This study suggests that in many cases (and possibly especially in families with multiple affected individuals), there are several different genetic influences leading to IDDM.

Phytohemagglutin-induced lymphocyte transformation in oral contraceptive users.

Phytohemagglutin (PHA)-induced lymphocyte transformation (PILT) was determined in 217 women taking oral contraceptives and 203 control women by means of the uptake of 3H-thymidine into DNA of lymphocytes cultured in heterologous serum. Depressed PILT responses were observed in oral contraceptive users as compared with age-matched controls, and the magnitude of depression correlated with the duration of oral contraception and was inversely related to the clinical progestagenic potency of the component steroids. An additional group of 21 women, tested within 1 year (mean 3 months) of cessation of oral contraception, showed persistent depression of PILT responses. Suppression of lymphocyte transformation in autologous as compared with homologous, normal serum suggests that serum inhibitory factors amy be important. We found no evidence for a direct suppressive in vitro effect of synthetic estrogens and gestagens. The prevalence of autoantibodies in oral contraceptive users was similar to that in control subjects.

Simple solid-phase radioimmunoassays for total tri-iodothyronine and thyroxine in serum, and their clinical evaluation.

1. Simple solid-phase radioimmunoassay methods for total tri-iodothyronine and thyroxine in serum or plasma are described. By using antibodies that are covalently coupled to microcrystalline cellulose, virtually identical assay procedures can be used for the determination of both hormones. An alkaline sodium glycinate buffer provides better assay conditions than the buffers often recommended for thyroid hormone radioimmunoassay. 2. Assay results are unaffected by moderate sample haemolysis. Plasma samples stored at room temperature for more than nine days often show an apparent increase in concentration of both thyroid hormones. 3. Serum tri-iodothyronine and thyroxine concentrations in healthy euthyroid subjects, and in euthyroid pregnant women are reported. In a series of 100 consecutive patients referred to a thyroid clinic the tri-iodothyronine assay discriminated better than the thyroxine assay between hyperthyroid and euthyroid patients. The thyroxine assay was much better than the tri-iodothyronine assay in discriminating between hypothyroid and euthyroid patients.

Some studies on the polyethylene glycol turbidity method for detecting immune complexes in serum.

A rapid and simple method for detecting circulating immune complexes based on turbidity measurements following polyethylene glycol precipitation was studied with regard to its suitability as a routine assay in clinical laboratories. This method was found to have an acceptable degree of precision provided the temperature was carefully controlled. The mean value obtained with a group for 70 blood donors was 0.09 (SD 0.05) and the 90th percentile value was 0.16. There was no significant difference between values obtained from groups divided on the basis of age or sex. Of 70 diabetic sera assayed by the polyethylene glycol turbidity method, 20% gave positive values although only 10% were strongly positive. The corresponding figures for the solid phase Clq binding method were 15.7% and 14.3%, respectively. Correlation between the two methods was poor. It was concluded that although both methods have a similar likelihood of detecting immune complexes in randomly selected diabetics, it is probable that different immune complexes were being detected.

Control of severe thyrotoxicosis with potassium iodide and propranolol.

Conventional preparation of thyrotoxic patients for surgery using thiouracils and iodides may not be possible because of either, inability to obtain satisfactory therapeutic levels of the drugs or idiosyncratic reactions to the drugs. An alterative regime using potassium iodide and propranolol in combination has previously been shown to be both safe and effective in the pre-operative control of mild to moderate thyrotoxicosis. The use of this combination in a patient with severe thyrotoxicosis is described. Potassium iodide and propranolol can be used successfully to prepare patients with all degrees of thyrotoxicosis for surgery.