Metabolic syndrome in subjects at high risk for type 2 diabetes: the genetic, physiopathology and evolution of type 2 diabetes (GENFIEV) study

BACKGROUND AND AIM

We evaluated the relationship between insulin resistance (IR) and insulin secretion with the metabolic syndrome (MS) in 885 subjects (377 men/508 women, age 49±11 years, BMI 29±5.2kgm(-2)) at risk of diabetes enrolled in the genetics, pathophysiology and evolution of type 2 diabetes (GENFIEV) study.

METHODS AND RESULTS

All subjects underwent a 75-g oral glucose tolerance test (OGTT) for the estimation of plasma levels of glucose and C-peptide, as well as fasting insulin and lipid profile. IR was arbitrarily defined as HOMA-IR value above the 75th centile of normal glucose tolerance (NGT) subjects. Overall MS prevalence (National Cholesterol Treatment Panel-Adult Treatment Panel (NCEP-ATPIII) criteria) was 33%, 19% in subjects with NGT, 42% in impaired fasting glucose (IFG), 34% in impaired glucose tolerance (IGT), 74% in IFG+IGT subjects, and 56% in newly diagnosed diabetic patients. Prevalence was slightly higher with IDF criteria. MS prevalence was >50% in subjects with 2h glucose >7.8mmoll(-1), independently of fasting plasma glucose. IR prevalence was higher in subjects with MS than in those without (63% vs. 23%; p<0.0001) and increased from 54% to 73% and 88% in the presence of three, four or five traits, respectively. IR occurred in 42% of subjects with non-diabetic alterations of glucose homeostasis, being the highest in those with IFG+IGT (IFG+IGT 53%, IFG 45%, IGT 38%; p<0.0001). Individuals with MS were more IR irrespective of glucose tolerance (p<0.0001) with no difference in insulinogenic index. Hypertriglyceridaemia (OR: 3.38; Confidence Interval, CI: 2.294.99), abdominal obesity (3.26; CI: 2.18-4.89), hyperglycaemia (3.02; CI: 1.80-5.07) and hypertension (1.69; CI: 1.12-2.55) were all associated with IR.

CONCLUSIONS

These results show that in subjects with altered glucose tolerance (in particular IFG+IGT) MS prevalence is high and is generally associated to IR. Some combinations of traits of MS may significantly contribute to identify subjects with IR.

Does parity increase insulin resistance during pregnancy?

AIMS

To study the effect of parity on impairment of insulin sensitivity during pregnancy and on the risk of gestational diabetes (GDM).

METHODS

We studied the relationship between parity and peripheral insulin sensitivity index (ISI(OGTT)) or GDM in 1880 caucasian women, who underwent a 100-g, 3-h oral glucose tolerance test (OGTT) between the 24th and 28th gestational week and in 75 women who underwent an OGTT in two consecutive pregnancies. A proxy for beta-cell function (basal plasma C peptide/fasting plasma glucose; CP/FPG) was also measured.

RESULTS

By univariate analysis parity was related to decreased ISI(OGTT) and to increased CP/FPG in those with parity > 3 and likewise GDM, diagnosed in 124 women (6.58%), was linearly related to parity (P = 0.0034) and strongly age dependent. The relationships between parity and ISI(OGTT), CP/FPG and GDM were no longer significant after adjustment for age, pregestational body mass index (BMI), and weight gain. GDM was significantly related to age and pregestational weight, while ISI(OGTT) and CP/FPG were inversely related to prepregnancy BMI or weight gain. In comparison with the index pregnancy, the subsequent pregnancy was characterized by an increase in actual and prepregnancy BMI, in 2 h area under curve (AUC) glucose and by a decrease in ISI(OGTT) (P = 0.0001). The longer the time interval between pregnancies and the higher the increment in pregestational BMI or in weight gain during the pregnancy, the greater were the ISI(OGTT) decrease and 2-h AUC glucose increase.

CONCLUSIONS

Parity is not directly linked to insulin sensitivity deterioration, to CP/FPG increase during pregnancy, or to GDM appearance, although it is linked through the mediation of progressive ageing and weight gain either before or during pregnancy, when there is a sufficiently long time interval between pregnancies.

Platelet antioxidant enzymes in insulin-dependent diabetes mellitus

BACKGROUND

The measurement of the peroxidase scavenging system represented by the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in blood cells of diabetic patients has, in the past, given equivocal results. Likewise, the role of these intracellular enzymatic scavengers against the oxidative stress of diabetes-associated microangiopathic complications is unknown.

METHODS

Choosing platelets as cell model (as commonly done in previous studies), the aim of this study was to relate the platelet content of SOD, catalase and GSH-Px to the presence of diabetes, as well as to the presence of nephropathy and retinopathy in 35 insulin-dependent diabetic patients, as compared to 10 age-matched control subjects.

RESULTS

The enzymatic activities were not changed in diabetic patients in comparison with healthy controls. After stratifying patients according to presence of nephropathy (24-h urinary albumin excretion rate persistently > or =20 microg min(-1)) or retinopathy, the group of albuminuric patients was characterized by a significant decrease in SOD activity as compared to those in the normoalbuminuric range (4.36+/-1.06 vs. 6.81+/-2.26 mU 10(-9) platelets; p=0.01). Catalase and GSH-Px did not change. No modification in platelet enzyme activities has been found in diabetic subjects with retinopathy.

CONCLUSIONS

These results suggest that diabetic nephropathy, at least in its early stage, may be related to an altered redox state of platelets, as tested by the reduction in SOD activity, thus, indicating that the renal damage in these patients may be associated to a selective increase in platelet susceptibility to variation in the redox state.

Persistent activation of CD8+ T-cells characterizes prediabetic twins

OBJECTIVE

Elevated circulating levels of activated CD3+ T-cells are characteristic of type I diabetes at diagnosis, and activated CD8+ (cytotoxic/suppressor) T-cells predominate in the islet infiltrate. The aim of this study was to examine the peripheral blood of prediabetic and nondiabetic identical twins of patients with type I diabetes for the presence of activated CD8+ T-cells and by comparing these groups, analyze the relationship of such cells to the development of the disease.

RESEARCH DESIGN AND METHODS

In a 10-year prospective study, blood T-cell subsets (CD3+ total T-cells, CD4+ helper/inducer, and CD8+ cytotoxic/suppressor) were analyzed for evidence of activation (cell surface expression of HLA-DR, CD25) in 18 identical twins of patients with type I diabetes, 8 of whom became diabetic (prediabetic twins), while 10 remained nondiabetic after at least 8 years of follow-up and are now at low risk for type I diabetes. Fifteen healthy individuals were studied as control subjects.

RESULTS

At the beginning and during the study, percentage levels of activated CD3+ HLA-DR+ T-cells were significantly elevated in prediabetic and low-risk twins compared with control subjects (P < 0.005) but remained high only in prediabetic twins (P < 0.005). Both prediabetic and low-risk twins had elevated levels of HLA-DR+ CD4+ T helper cells compared with control subjects throughout the study (P < 0.001), and these remained high in both (P < 0.001 and P < 0.05, respectively). Only prediabetic twins had elevated levels of HLA-DR+ CD8+ T-cells during the study. These were significantly higher than in control subjects (P < 0.005) and low-risk twins (P < 0.05) and remained persistently elevated to diagnosis (P < 0.001). Abnormally elevated levels of HLA-DR+ CD8+ T-cells in twins indicate a 50% risk of progression to type I diabetes by life-table analysis (P = 0.01), with a positive predictive value of 100%, sensitivity of 50%, and specificity of 100%. Elevated CD25+ T-cell levels in prediabetic and low-risk twins were less marked and less able to discriminate between the twin groups.

CONCLUSIONS

These results demonstrate that prediabetes is characterized by persistent elevation of HLA-DR+ CD8+ T-cells with the same cytotoxic phenotype as cells predominating in the islet at diagnosis, suggesting that the circulating cells may have a role in the pathogenesis of islet damage.

Increased expression of T-cell markers of immunological memory associated with protection from type I diabetes. A study of identical twins

Disturbances in the balance of CD4+ helper T-lymphocytes expressing the surface molecules CD45RA and CD45R0, which define naive and memory populations, respectively, are present at diagnosis of type I diabetes. In a prospective study over 10 years, these subsets were analyzed in samples obtained from 18 identical twins of patients with type I diabetes, 8 of whom became diabetic (prediabetic twins), whereas the rest remained nondiabetic after at least 8 years follow-up and are now unlikely to develop the disease (diabetes-protected twins). At the beginning of the study, percentage levels of naive (CD45RA+) CD4+ lymphocytes were significantly elevated in prediabetic twins compared with diabetes-protected twins (P < 0.05) and remained so throughout the study (P < 0.01). Percentage levels of naive cells in diabetes-protected twins were significantly reduced compared with control subjects both at the beginning and throughout the study (P < 0.05, P < 0.01, respectively). In contrast, diabetes-protected twins at the beginning of the study had elevated percentage levels of memory (CD45R0+) CD4+ lymphocytes that persisted throughout the study compared with prediabetic twins (P < 0.05 for both). Percentage levels of memory cells in prediabetic twins were significantly reduced compared with control subjects both at the beginning and throughout the study (P < 0.01, P < 0.05, respectively). Increased percentage levels of a population of CD4+ lymphocytes coexpressing CD45RA and CD45R0 were seen in both twin groups compared with control subjects at entry into and during the study (P < 0.05 for all), but persisted only in the prediabetic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

Importance of persistent cellular and humoral immune changes before diabetes develops: prospective study of identical twins

OBJECTIVES

To determine the pattern of cellular and humoral immune changes associated with insulin dependent diabetes before diabetes develops.

DESIGN

Prospective study over 10 years of 25 non-diabetic identical twins of patients with insulin dependent diabetes. The non-diabetic twins were followed up either till they developed diabetes or to the end of the study.

SETTING

Teaching hospital.

SUBJECTS

25 non-diabetic identical cotwins of patients with diabetes; 46 controls of the same sex and similar age tested over the same period. Of the 25 twins (total follow up 144 patient years), 10 developed diabetes (prediabetic twins); the remainder were followed up for a mean of 7.7 years.

MAIN OUTCOME MEASURES

Results of glucose tolerance tests or fasting blood glucose concentrations at each sample point. Measurements of activated T lymphocytes, expressing the HLA-DR antigen, islet cell antibodies, and insulin autoantibodies in samples.

RESULTS

All 10 prediabetic twins had both cellular and humoral changes initially and in most samples before diabetes was diagnosed (activated T lymphocytes in 39/40, islet cell antibodies in 45/47, and insulin autoantibodies to islet cells and insulin were detected infrequently (in 8/54, 6/69, and 0/69 samples, respectively). The combination of cellular and humoral (islet cell antibodies or insulin autoantibodies) immune changes were detected in all 10 of the prediabetic twins but in only one of the 15 non-diabetic twins (P < 0.001). The positive predictive value in this cohort of increased percentages of activated T cells and the presence of antibodies to islet cells or insulin on two consecutive occasions was 100%.

CONCLUSION

Most of the twins had cellular or humoral immune changes at some stage. A combination of cellular and humoral immune changes and their tendency to persist is highly predictive of insulin dependent diabetes and distinguishes twins who develop diabetes from those who do not.

Increase in simultaneous coexpression of naive and memory lymphocyte markers at diagnosis of IDDM

The monoclonal antibodies 2H4 (anti-CD45RA) and UCHL1 (anti-CD45RO) were used to subdivide the CD4 and CD8 T-cell subsets into naive and memory cells. The peripheral blood lymphocytes of 34 patients with recent-onset IDDM, 21 patients with long-standing IDDM, and healthy control subjects of similar age and sex were analyzed by a three-color immunofluorescence technique. CD4 and CD8 lymphocytes expressed the CD45 isoforms alone (CD45RA+ or CD45RO+) or in combination CD45RA+RO+). Simultaneous coexpression of both CD45RA and CD45RO (CD45RA+RO+) on CD4 and CD8 lymphocytes in patients with recent-onset IDDM was higher than in control subjects (P < 0.001). The proportion of CD4 lymphocytes expressing CD45RA alone (CD45RA+RO-) was similar in these groups, but the percentage of CD8 lymphocytes that were CD45RA+RO- was significantly higher in the patients with recent-onset IDDM (P < 0.05). The result of these changes is a significant increase in expression of naive phenotypes (CD45RA+ and CD45RA+RO+) on CD4 and CD8 lymphocytes in recent-onset IDDM (P < 0.005 and P < 0.0001). In long-standing IDDM, total CD45RA+ expression on CD4 and CD8 lymphocytes was reduced compared with control subjects (P < 0.05) as a result of a tendency of CD45RA+RO- and CD45RA+RO+ subsets to be lower. This increase in total naive (CD45RA+) lymphocytes and in coexpression of naive (CD45RA) and memory (CD45RO) markers on CD4 and CD8 lymphocytes subsets in patients with recent-onset IDDM suggests that abnormal regulation of T-cell activation and maturation is important in the pathogenesis of the disease.

Erythrocyte spermidine levels in IDDM patients

OBJECTIVES

To evaluate whether erythrocyte levels of polyamines spermidine and spermine (expressed in nmol/ml packed erythrocytes [PRBCs]) are modified in insulin-dependent diabetes mellitus (IDDM) and are associated with the presence of retinopathy or nephropathy.

RESEARCH DESIGN AND METHODS

We studied erythrocyte spermidine and spermine levels in 38 IDDM patients with or without persistent microalbuminuria (urinary albumin excretion rate [AER] between 20 and 200 micrograms/min), macroalbuminuria (AER greater than 200 micrograms/min), or retinopathy compared with 60 sex- and age-matched control subjects.

RESULTS

Mean +/- SD erythrocyte spermine content was similar in both diabetic (9.7 +/- 5.5 nmol/ml PRBCs) and control (8.8 +/- 3.5 nmol/ml PRBCs) subjects, whereas spermidine was higher in diabetic (19.1 +/- 7.2 nmol/ml PRBCs) than in control (14.5 +/- 4 nmol/ml PRBCs, P = 0.0007) subjects. Moreover, spermidine was significantly higher in the groups with microalbuminuria (n = 11, 22.5 +/- 9.2 nmol/ml PRBCs) and macroalbuminuria (n = 4, 22.2 +/- 5.7 nmol/ml PRBCs) than in both normoalbuminuric (n = 23, 16.9 +/- 5.6 nmol/ml PRBCs) and control (F = 9.78, P = 0.0001) subjects, and correlated with log AER (r = 0.41, P = 0.009). Similarly, proliferative retinopathy was associated with a significant increase in spermidine (n = 5, 20 +/- 7 nmol/ml PRBCs compared with control subjects [P = 0.0009]).

CONCLUSIONS

Our data suggest that erythrocyte spermidine content is increased in IDDM patients associated with both diabetic nephropathy and advanced retinopathy.

T lymphocyte activation is associated with viral replication in chronic hepatitis B virus infection of childhood

Activated circulating T lymphocytes expressing HLA-DR (mean +/- s.d. 11.0 +/- 5.2%) or interleukin-2 receptor (IL-2R) (2.1 +/- 1.7%) were significantly increased in 63 children with chronic hepatitis B virus (HBV) infection when compared with 33 age-matched healthy controls (3.0 +/- 1.3%, P less than 0.01, and 0.1 +/- 0.4%, P less than 0.01). HBeAg-positive patients had higher percentage of DR (11.9 +/- 5.1%) or IL-2R (2.4 +/- 1.7%) positive T lymphocytes than anti-HBe-positive children (7.4 +/- 3.6% and 1.1 +/- 1.5%, P less than 0.01 and P = 0.02 respectively). Similarly, HBV DNA-positive patients had higher percentage of DR (10.5 +/- 3.3) or IL-2R (3.2 +/- 1.7%) positive T cells than HBV DNA-negative children (6.6 +/- 2.8% and 1.2 +/- 1.5%, P less than 0.01 for both). There was a positive correlation between percentage of DR positive T lymphocytes and levels of HBV DNA. Sixty-two per cent of the DR-positive T lymphocytes were cytotoxic/suppressor and 35% helper/inducer. The relationship between viral replication and T lymphocyte activation is discussed.

Serum lipids and lipoproteins in type 2 diabetic patients with persistent microalbuminuria

To investigate whether persistent microalbuminuria is related to altered levels of both lipids and apolipoproteins in Type 2 diabetes mellitus serum total-cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, apolipoprotein A-I, and apolipoprotein B were measured by standard methods in a group of Type 2 diabetic patients affected by persistent microalbuminuria (albumin excretion rate (AER) 20-200 micrograms min-1) as compared with a group of sex- and age-matched non-microalbuminuric patients (AER less than 20 micrograms min-1). The groups were stratified according to a short (less than or equal to 5 years) or a longer (greater than 5 years) duration of diagnosed diabetes. Microalbuminuria was not associated with significant changes of serum total-cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, and apolipoproteins in the group of patients with a duration of disease greater than 5 years, while microalbuminuric patients less than or equal to 5 years from diagnosis (n = 11) had serum total-cholesterol, triglycerides, LDL-cholesterol, and apoprotein B higher than non-microalbuminuric control patients (n = 26) (cholesterol 6.2 +/- 0.9 vs 5.1 +/- 1.0 mmol l-1 (p = 0.003); triglycerides 2.1 +/- 0.7 vs 1.7 +/- 1.3 mmol l-1 (p = 0.03); LDL-cholesterol 4.1 +/- 0.8 vs 3.0 +/- 0.7 mmol l-1 (p less than 0.001); apo-B 1.3 +/- 0.3 vs 1.1 +/- 0.3 g l-1 (p = 0.02). In these patients with shorter duration of diabetes many of the serum lipid measures correlated positively with AER.

Serum spermidine oxidase activity in patients with insulin-dependent diabetes mellitus and microvascular complications

Metabolism of polyamines (spermidine and spermine) is known to be strictly related to the growth processes of eukaryotic cells. Since cell replication processes appear altered in insulin-dependent diabetes mellitus (IDDM), especially when associated with its microvascular complications, the aim of this study was measuring serum spermidine oxidase activity (SOA), a key enzyme in the metabolic pathway of polyamines, in 47 patients with IDDM as compared with 63 healthy control subjects matched for age and sex. Mean SOA levels +/- SD were significantly lower in IDDM patients (177.4 +/- 57.2 mu kat/l) than in controls (247.6 +/- 68.1 mu kat/l; p less than 0.001), being SOA inversely related with daily insulin dose. SOA was moreover significantly higher (but similar to controls) in the group with increased urinary albumin excretion rate (AER persistently greater than 20 micrograms/min); (n = 17; 213.1 +/- 62.6 mu kat/l) in comparison with normoalbuminuric subjects (n = 30; 156.6 +/- 43.5 mu kat/l; F = 21.78; p = 0.0001). SOA was correlated with AER (r = 0.45; p = 0.001), independently of age, duration of disease, serum creatinine, body weight, blood pressure and metabolic control, as shown by a multiple regression analysis model (p = 0.003). Presence of background retinopathy was not associated with modified levels of SOA, which was conversely higher, although not significantly, in the patients with proliferative retinal lesions. In conclusion serum SOA is deeply altered in IDDM patients, being markedly reduced in the whole group of patients and conversely independently increased up to the mean values of controls in presence of increased AER or advanced retinopathy.

Alterations in T-lymphocyte subpopulations in type I diabetes. Exploration of genetic influence in identical twins

To evaluate factors influencing the alteration in subsets of T-lymphocytes, we studied 24 pairs of identical twins discordant for insulin-dependent (type I) diabetes mellitus. Subsets were assessed by monoclonal antibodies and a pure preparation of peripheral blood mononuclear cells obtained by centrifugation of heparinized whole blood with a Ficoll/Triosil gradient. In 12 pairs studied within 5 yr of diagnosis, we observed a reduction in the percentage of cells reacting with OKT8 (recognizing the CD8 antigen present on the suppressor/cytotoxic subset) (P less than .05), but a similar level was detected in their nondiabetic cotwins. In 12 pairs studied greater than 5 yr after the diagnosis and in whom the nondiabetic twin is less likely to develop diabetes, the percentage of cells reacting with OKT8 was reduced in both the diabetic (P less than .05) and the nondiabetic (P less than .01) twins. Reductions were also seen with OKT3 (recognizing the CD3 antigen present on the total T-lymphocyte population) and OKT4 (recognizing the CD4 antigen present on the helper/inducer subset), but only in the diabetic twins from the group with longer discordance. We conclude that a reduced percentage of suppressor/cytotoxic cells is associated with type I diabetes, but the reduction appears to be genetically determined. Total T-lymphocytes are also reduced but mainly in the helper/inducer subset and only in diabetic patients of long duration. Such a reduction cannot therefore be primarily genetically determined.

Evidence that the reduced number of natural killer cells in type 1 (insulin-dependent) diabetes may be genetically determined

Viruses may cause Type 1 (insulin-dependent) diabetes. We wondered whether the number and function of natural killer cells, which are important in anti-viral defense, are disturbed in diabetic patients. We studied 16 recently diagnosed Type 1 diabetic patients, 18 Type 1 diabetic patients diagnosed more than 15 years previously, 18 Type 2 (non-insulin-dependent) diabetic patients and 23 control subjects. We determined the number of natural killer cells (expressed as log10%) using anti-Leu 11 monoclonal antibody and the function (in log10 lytic units) concurrently using a 51Cr release assay with K562 as target cells. We found that the number of natural killer cells was reduced in Type 1 diabetes (1.01 +/- 0.04) as compared with Type 2 diabetic patients (1.16 +/- 0.04, p = 0.004) and normal control subjects (1.16 +/- 0.04, p = 0.006). To establish whether the reduced natural killer cell number is genetically determined we studied 19 identical twin pairs discordant for Type 1 diabetes; we found that even the non-diabetic co-twins had a reduced natural killer cell number (0.93 +/- 0.05, p = 0.0006) as compared with normal control subjects. Natural killer cell function was similar in all groups while natural killer activity per cell was significantly increased in the recently diagnosed diabetic patients (1.63 +/- 0.07) as compared with long-standing diabetic patients (1.26 +/- 0.26, p = 0.03) and controls subjects (1.36 +/- 0.07, p = 0.006). In conclusion the reduced number of natural killer cells in Type 1 diabetes appears to be genetically determined while their activity at diagnosis is increased.

Preferential activation of helper/inducer T lymphocytes in autoimmune chronic active hepatitis

We found a significant increase of activated circulating T lymphocytes expressing interleukin 2 receptor (IL-2r) (mean +/- s.e.m. 11.0 +/- 1.1%) or DR antigen (5.0 +/- 0.49%) in patients with autoimmune chronic active hepatitis (CAH) starting in childhood when compared to healthy controls (0.14 +/- 0.09%, P less than 0.001 and 2.8 +/- 0.06%, P less than 0.01). Patients with liver disorders due to Wilson's disease (IL-2r 0.64 +/- 0.25%, DR 3.5 +/- 0.22%) or alpha-1-antitrypsin deficiency (IL-2r 0.1 +/- 0.06%, DR 2.8 +/- 0.35%) had levels similar to controls. Levels of both IL-2r and DR positive T lymphocytes were higher in patients with uncontrolled CAH (IL-2r 18.0 +/- 1.01%; DR 6.3 +/- 0.78%) than in patients with inactive disease (IL-2r 3.2 +/- 1.4%, P less than 0.001; DR 3.0 +/- 0.13%, P less than 0.01). In patients with active disease levels of IL-2r positive cells were higher than DR positive cells (P less than 0.001). Only 21% of activated T cells coexpressed the two markers of activation. Sixty-seven percent of IL-2r positive T lymphocytes were helper/inducer and 25% suppressor/cytotoxic, while 66% of the DR positive T cells were suppressor/cytotoxic and 31% helper/inducer. The finding that the highest levels of activated T lymphocytes are present in patients with uncontrolled CAH suggests that these cells are involved in its pathogenesis. The preferential increase of activated helper/inducer cells might explain the enhanced immune reactivity characteristic of autoimmune CAH.

Immune changes associated with insulin dependent diabetes may remit without causing the disease: a study in identical twins

Activation of T lymphocytes and islet cell antibodies were studied in two groups of insulin dependent diabetics and their non-diabetic identical cotwins. Group 1 comprised 12 "short term" twin pairs (diabetic twin diagnosed less than five years previously) in whom only a third of the cotwins were likely to develop diabetes; 10 of the 12 non-diabetic cotwins showed increased values of activated T lymphocytes, islet cell antibodies, or both. Group 2 comprised 10 "long term" twin pairs (diabetic twin diagnosed more than 11 years previously) in whom none of the non-diabetic cotwins was likely to develop diabetes; these pairs were selected because all the non-diabetic cotwins had shown islet cell antibodies at some time in the past, but only two still did so (one with an increased value of activated T cells). There was relative glucose intolerance in the cotwins of the short term group but not in those of the long term group. Non-diabetic cotwins of diabetics may show the immune changes associated with insulin dependent diabetes and relative glucose intolerance, but these changes may remit without leading to diabetes.

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.

An abortive form of pemphigus vulgaris probably induced by penicillin

A case of an abortive form of pemphigus probably induced by protracted penicillin treatment is reported. Because of a positive patch test with penicillamine and the finding of such an amino acid in patient's plasma, the authors are induced to believe that the trigger factor could really have been penicillamine formed by the metabolic breakdown of the penicillin molecule.

Pathogenicity of the intercellular antibodies of pemphigus and their periodic removal from the circulation by plasmapheresis

The authors are convinced that the intercellular antibodies of pemphigus are pathogenic. Consequently periodic plasmapheresis in two patients with pemphigus has been performed to remove the antibodies from the circulation. After larger plasma-exchanges there was a decrease of the antibody titre and a parallel improvement of the clinical condition.