Diabetes and gender

It is often assumed that there is little or no sex bias within either Type I (insulin-dependent) or Type II (non-insulin-dependent) diabetes mellitus. This review considers evidence that sex effects of interest and importance are present in both forms of the disease. Type I diabetes is the only major organ-specific autoimmune disorder not to show a strong female bias. The overall sex ratio is roughly equal in children diagnosed under the age of 15 but while populations with the highest incidence all show male excess, the lowest risk populations studied, mostly of non-European origin, characteristically show a female bias. In contrast, male excess is a consistent finding in populations of European origin aged 15-40 years, with an approximate 3:2 male:female ratio. This ratio has remained constant in young adults over two or three generations in some populations. Further, fathers with Type I diabetes are more likely than affected mothers to transmit the condition to their offspring. Women of childbearing age are therefore less likely to develop Type I diabetes, and--should this occur--are less likely to transmit it to their offspring. Type II diabetes showed a pronounced female excess in the first half of the last century but is now equally prevalent among men and women in most populations, with some evidence of male preponderance in early middle age. Men seem more susceptible than women to the consequences of indolence and obesity, possibly due to differences in insulin sensitivity and regional fat deposition. Women are, however, more likely to transmit Type II diabetes to their offspring. Understanding these experiments of nature might suggest ways of influencing the early course of both forms of the disease.

Mental disorders and suicide in Northern Ireland

BACKGROUND

The aim of this part of the Northern Ireland Suicide Study was to investigate the prevalence of DSM-III-R axis I (clinical syndrome) and axis II (personality) disorders among suicides (14 years and older) in Northern Ireland during a one-year period.

METHOD

A psychological autopsy study based on a variety of documentary sources and interviews with bereaved informants and health care professionals.

RESULTS

Ninety per cent of suicides (106/118) had a current axis I and/or an axis II mental disorder. At least one current axis I disorder was diagnosed in 86% of suicides (102/118), and at least one axis II disorder was diagnosed in 44% (52/118). Suicides under 30 years (92% male) were less likely to have a current axis I disorder (68%; 26/38) than those 30 years and older (95%; 76/80). Psychiatric comorbidity was present in 55% of suicides (65/118). The time between the last contact with a health care professional and death was greater among suicides under 30 years and male suicides.

CONCLUSIONS

Notwithstanding the aetiological complexity of suicide, the prevention, recognition and treatment of mental disorder will continue to play key roles in suicide prevention.

Risk factors for suicide independent of DSM-III-R Axis I disorder. Case-control psychological autopsy study in Northern Ireland

BACKGROUND

The vast majority of suicides suffer from at least one mental disorder at the time of death.

AIMS

To identify risk factors for suicide, particularly those independent of current DSM-III-R Axis I disorder(s).

METHOD

A case-control psychological autopsy study comparing suicides with matched community controls.

RESULTS

Independent risk factors for suicide included: Axis II (personality) disorder (particularly antisocial, avoidant and dependent); at least one of 12 life events (from the List of Threatening Experiences) during the previous 52 or 4 weeks (in particular, a 'serious problem with close friend, neighbour or relative'); current unemployment; previous history of deliberate self-harm; and contact with a GP within 26 weeks. Relative to individuals with no current mental disorder, the estimated risk of suicide in those with Axis I-Axis II comorbidity (OR 346.0) was significantly greater than that in those with Axis I disorder(s) only (OR 52.4).

CONCLUSIONS

Suicide risk assessment may be enhanced by enquiry about the aforementioned independent risk factors, and attention to Axis I-Axis II comorbidity.

Relative predispositional effects of HLA class II DRB1-DQB1 haplotypes and genotypes on type 1 diabetes: a meta-analysis

The direct involvement of the human leukocyte antigen class II DR-DQ genes in type 1 diabetes (T1D) is well established, and these genes display a complex hierarchy of risk effects at the genotype and haplotype levels. We investigated, using data from 38 studies, whether the DR-DQ haplotypes and genotypes show the same relative predispositional effects across populations and ethnic groups. Significant differences in risk within a population were considered, as well as comparisons across populations using the patient/control (P/C) ratio. Within a population, the ratio of the P/C ratios for two different genotypes or haplotypes is a function only of the absolute penetrance values, allowing ranking of risk effects. Categories of consistent predisposing, intermediate ('neutral'), and protective haplotypes were identified and found to correlate with disease prevalence and the marked ethnic differences in DRB1-DQB1 frequencies. Specific effects were identified, for example for predisposing haplotypes, there was a statistically significant and consistent hierarchy for DR4 DQB1*0302s: DRB1*0405 =*0401 =*0402 > *0404 > *0403, with DRB1*0301 DQB1*0200 (DR3) being significantly less predisposing than DRB1*0402 and more than DRB1*0404. The predisposing DRB1*0401 DQB1*0302 haplotype was relatively increased compared with the protective haplotype DRB1*0401 DQB1*0301 in heterozygotes with DR3 compared with heterozygotes with DRB1*0101 DQB1*0501 (DR1). Our results show that meta-analyses and use of the P/C ratio and rankings thereof can be valuable in determining T1D risk factors at the haplotype and amino acid residue levels.

Hemodynamic effects of intravenous amiodarone in patients with depressed left ventricular function and recurrent ventricular tachycardia

The systemic hemodynamic effects of intravenously administered amiodarone were evaluated in patients with depressed left ventricular function and recurrent sustained ventricular tachycardia. Heart rate decreased linearly up to 1 hour after amiodarone infusion (5 mg/kg). Cardiac index varied in a cubic fashion, diminishing at 10 minutes and returning to baseline by 60 minutes (p less than 0.05). Stroke work index also showed a similar decrease at 10 minutes, which was transient (p less than 0.005). These changes occurred without any significant change in systemic vascular resistance and with slight or no increase in pulmonary capillary wedge pressure, indicating a negative inotropic effect of amiodarone. The depression of left ventricular function in these patients, however, was mild and transient, and intravenously administered amiodarone was tolerated by the vast majority of patients. In two patients with overt heart failure and severely depressed left ventricular ejection fraction and marked hemodynamic abnormalities, profound hypotension occurred during amiodarone therapy; in such patients, therefore, hemodynamic monitoring is preferable. Limited data are available on the hemodynamic effects of orally administered amiodarone, but the determination of left ventricular ejection fraction by radionuclide ventriculography before and during long-term amiodarone administration has shown no reduction of function even in patients with severely reduced myocardial performance.

Levamisole induces interleukin-18 and shifts type 1/type 2 cytokine balance

Immune responses can be classified, according to the predominant cytokines involved, into type 1 (featuring interferon-gamma, IFN-gamma) and type 2 (featuring interleukin-4, IL-4); imbalance between type 1 and type 2 cytokine compartments has been implicated in many human diseases. Levamisole is a drug with an unknown mode of action that has been used to boost immunity in infectious diseases including leprosy, and in some cancers. To test the hypothesis that levamisole acts by inducing a shift to a type 1 immune response, we used Brown Norway (BN) rats, which are markedly biased to type 2 responses. BN rats treated with levamisole showed a dose-dependent rise in serum IFN-gamma and fall in serum immunoglobulin E (IgE) level. Detailed analysis of cytokine gene expression showed upregulation of IFN-gamma and downregulation of IL-4 messenger RNA. This coincided with marked upregulation of IL-18, a recently characterized cytokine with potent activity in stimulating IFN-gamma production. IL-12 was not induced. Further, the type 2 response induced in BN rats by mercuric chloride was markedly attenuated when rats were pretreated with levamisole: there was a 2-log reduction in maximum serum IgE level and marked attenuation of IL-4 gene upregulation. These data indicate that levamisole acts by resetting the immune balance towards a type 1 response via induction of IL-18. Our findings provide a direction for development of more specific immunomodulating therapy.

Blood pressure regulation in Alzheimer's disease

Brain neurons which regulate blood pressure (BP), including the C-1 tonic vasomotor neurons, degenerate in Alzheimer's disease (AD). This study determines whether BP is decreased in AD. We reviewed records of three autopsy proven AD patients. Medical causes for decreased BP were investigated. Yearly averages for systolic (SBP), diastolic (DBP), mean arterial (AP) blood pressure and pulse pressure (PP) were calculated. BP in the year of diagnosis was compared to the sum of all BP in subsequent years. In addition, each yearly measurement through the course of AD was compared to its counterpart in the year of diagnosis. Three BP measurements were significantly decreased by from 6.9% to 15.9% in all patients when BP in the year of diagnosis was compared to the sum of each pressure in subsequent years. Sustained BP declines started in the third to fourth year after diagnosis of AD and continued for up to 9 years. The PP was decreased by 19.9% in one patient. There was a strong correlation between the number of C-1 neurons in these cases and their AP and SBP in the years after diagnosis. Hypothalamic phenylethanolamine N-methyltransferase activity was decreased by 63% in AD compared to control cases. Neurofibrillary tangles were found in the paraventricular nucleus of the hypothalamus in an AD case. We postulate that BP is altered in AD as neurons which regulate it degenerate.

Reduced clearance of exogenous dopamine in rat nucleus accumbens, but not in dorsal striatum, following cocaine challenge in rats withdrawn from repeated cocaine administration

We investigated whether changes in the dopamine transporter in the nucleus accumbens or striatum are involved in cocaine-induced behavioral sensitization by using in vivo electrochemistry to monitor the clearance of locally applied dopamine in anesthetized rats. Rats were injected with cocaine-HCl (10 mg/kg i.p.) or saline daily for 7 consecutive days and then withdrawn for 7 days. Pressure ejection of a finite amount of dopamine at 5-min intervals from a micropipette adjacent to the electrochemical recording electrode produced transient and reproducible dopamine signals. After a challenge injection of cocaine (10 mg/kg i.p.), the signals in the nucleus accumbens of cocaine-treated animals became prolonged and the clearance rate of the dopamine decreased, indicating significant inhibition of the dopamine transporter. In contrast, simultaneous measurements in the dorsal striatum indicated a transient increase in both the amplitude of the signals and the clearance rate of the dopamine. The signals in both brain regions in the saline-treated animals given the cocaine challenge were similar to those in untreated animals given an acute injection of cocaine (10 mg/kg i.p.) or saline. Behaviorally, not all of the cocaine-treated animals were sensitized; however, both sensitized and nonsensitized animals displayed similar changes in dopamine clearance rate. Quantitative autoradiography with [3H]mazindol revealed that the affinity of the dopamine transporter for cocaine and the density of binding sites were similar in cocaine- and saline-treated rats. The decrease in dopamine clearance rate observed in the nucleus accumbens of the cocaine-treated rats after a challenge injection of cocaine is consistent with increased dopaminergic transmission, but does not appear to be sufficient in itself for producing behavioral sensitization.

Compounds that induce autoimmunity in the brown Norway rat sensitize mast cells for mediator release and interleukin-4 expression

Brown Norway (BN) rats given mercuric chloride (HgCl2), gold (Au) salts or D-penicillamine develop a T helper 2 (Th2) cell-mediated autoimmune syndrome. The recent observation of tissue injury within 24 h of HgCl2 treatment suggested the involvement of a non-T cell. We therefore examined the effect of these compounds on rat mast cells in vitro. Incubation of BN rat peritoneal mast cells with HgCl2 enhanced the release of serotonin in response to IgE cross-linking agents. Mast cells from Lewis rats, a strain not susceptible to the autoimmune syndrome in vivo, were affected to a lesser extent. The effect was observed with purified BN mast cells, suggesting a direct action. Similar effects were seen with D-penicillamine in the presence of copper ions, a combination that produces hydrogen peroxide, and Au. HgCl2 caused significant induction of interleukin (IL)-4 mRNA in mast cells from BN, but not Lewis rats. The data demonstrate a novel enhancing effect of a number of compounds on mast cell mediator release, and an inducing effect of HgCl2 on mast cell IL-4, expression. These findings are consistent with our hypotheses that mast cells may contribute to early tissue injury, and also, via production of IL-4, may initiate and/or augment, the Th2 response in the BN rat model of chemical-induced autoimmunity.

Progression to diabetes in relatives with islet autoantibodies. Is it inevitable?

OBJECTIVE

A large cohort of family members with islet cell antibodies (ICA) > or = 20 Juvenile Diabetes Foundation units (JDF U) was examined to determine whether there was a subgroup at low risk of progression to diabetes; whether risk of progression changed over time; and whether rate of progression to diabetes varied according to age, islet autoantibodies, and genetic markers of susceptibility.

RESEARCH DESIGN AND METHODS

Individuals with ICA > or = 20 JDF U were identified from 4,423 family members recruited to prospective family studies in the U.K. Subjects were followed for up to 18 years. Antibodies to insulin, GAD, and IA-2 were measured in the first sample, and HLA class II typing was performed.

RESULTS

Of 147 family members with ICA > or = 20 JDF U on at least one occasion, 29 developed type 1 diabetes after a median of 3.2 years (maximum 18.1). The cumulative risk of developing diabetes within 15 years was 47% (95% CI 28-67) for all family members with ICA > or = 20 JDF U, 2.8% (0-8.2) for those with ICA alone, and 66% (44-87) for those with at least one additional autoantibody marker. There were no differences in age, HLA class II type, or levels of ICA, insulin autoantibodies, or IA-2 antibodies between those who developed diabetes within 5 years of testing and those who developed diabetes after this time. GAD antibody levels we ..., however, higher in those who progressed more slowly.

CONCLUSIONS

Family members with ICA alone are at low risk of progression to diabetes. Rapid development of disease after ICA detection could not be distinguished from delayed development on the basis of autoantibodies or markers of genetic susceptibility, and those with multiple antibodies remained at high risk throughout long-term follow-up. This suggests that all family members with multiple islet autoantibodies are destined to develop autoimmune diabetes.

Th1/Th2 cytokine gene expression after mercuric chloride in susceptible and resistant rat strains

Mercuric chloride (HgCl2) has contrasting effects on different rat strains: susceptible strains, e.g. Brown Norway (BN) develop polyclonal B cell activation, multiple autoantibodies and widespread tissue injury. Lewis (LEW) rats are resistant: no autoimmune response occurs after HgCl2; instead, there is immunosuppression. We have previously shown, by fully quantitative polymerase chain reaction (PCR), up-regulation of interleukin-4 (IL-4) gene expression in HgCl2-treated BN rats, implicating Th2 cells in the autoimmune syndrome. Involvement of the reciprocal Th1 subset, producing interferon-gamma (IFN-gamma), in resistance of LEW rats to HgCl2 has been suggested. We now report extensive analysis of Th1 and Th2 cytokine gene expression in spleen and lymph nodes of susceptible (BN) and resistant (LEW) rats after HgCl2. IL-4 and IFN-gamma were analyzed by quantitative PCR, other cytokines were assessed using semiquantitative PCR: the relative merits of these two techniques are discussed. We show pronounced up-regulation of IL-4 and more modest up-regulation of IFN-gamma in BN rats, but no up-regulation of either in LEW rats. Baseline levels of IFN-gamma were higher in Lew rats. Semiquantitative PCR showed increased expression of IL-2, IL-6 and IL-10 in BN; in LEW rats only IL-10 was increased. There was no marked change in IL-5, IL-13 or transforming growth factor-beta (TGF-beta) in either strain. These data further support the key role of IL-4 in HgCl2-induced autoimmunity, and suggest that failure of up-regulation of IL-4, together with higher baseline IFN-gamma expression, accounts for resistance of LEW rats to HgCl2. However, neither IFN-gamma nor TGF-beta can be implicated in HgCl2-induced immunosuppression in the LEW rat in vivo: our data suggest a role for IL-10 in this phenomenon.

Interleukin-4 gene expression in mercury-induced autoimmunity

Mercuric chloride (HgCl2) induces autoimmunity in Brown Norway (BN) rats, with necrotizing vasculitis in the gut. Circumstantial evidence implicates the Th2 subset of CD4+ T lymphocytes, which produces IL-4. We developed a quantitative polymerase chain reaction (PCR) technique to quantify IL-4 gene expression. A phagemid containing rat IL-4 cDNA was modified to act as the template for a synthetic RNA construct; a known amount of synthetic RNA was added to total RNA from spleen and caecum of BN rats at various times after HgCl2, followed by reverse transcriptase PCR. IL-4 gene expression increased markedly in spleen and caecum after HgCl2. Splenic levels peaked by 10 days at approximately five-times baseline, then returned towards normal as the autoimmune response was spontaneously regulated. Caecal IL-4 expression peaked at 48 h, at which time we observed a previously unreported early phase of tissue injury, with necrotizing vasculitis qualitatively similar to that reported previously in the later phases of the model. These data support a key role for IL-4 in this experimental model of autoimmunity. The quantitative PCR technique can be modified for analysis of other cytokines, allowing further investigation of the role of T cell subsets in this model.

Bidentate carbenoid ester coordination in ruthenium(II) Schiff-base complexes leading to excellent levels of diastereo- and enantioselectivity in catalytic alkene cyclopropanation

Exceptionally high stereoselectivity (ee < or = 98%, dr < or = 99:1) in the cyclopropanation of alkenes with ethyl diazoacetate using a non-planar ruthenium(II) Schiff-base precatalyst is a result of eta 2C,O binding of the carbenoid ester intermediate, according to DFT calculations.

A quarter of patients with type 1 diabetes have co-existing non-islet autoimmunity: the findings of a UK population-based family study

Individuals with type 1 diabetes (T1D) are at increased risk of coeliac disease (CD), autoimmune thyroiditis and autoimmune gastritis, but the absolute risks are unclear. The aim of this study was to investigate the prevalence of autoantibodies to tissue transglutaminase (TGA), thyroid peroxidase (TPOA) and gastric H⁺ /K⁺ -ATPase (ATPA) and their genetic associations in a well-characterized population-based cohort of individuals with T1D from the Bart's-Oxford family study for whom islet autoantibody prevalence data were already available. Autoantibodies in sera from 1072 patients (males/females 604/468; median age 11·8 years, median T1D duration 2·7 months) were measured by radioimmunoassays; HLA class II risk genotype was analysed in 973 (91%) using polymerase chain reaction with sequence specific primers (PCR-SSP). The prevalence of TGA (and/or history of CD), TPOA and ATPA in patients was 9·0, 9·6 and 8·2%, respectively; 3·1% had two or more autoantibodies. Females were at higher risk of multiple autoimmunity; TGA/CD were associated with younger age and TPOA with older age. ATPA were uncommon in patients under 5 years, and more common in older patients. Anti-glutamate decarboxylase autoantibodies were predictive of co-existing TPOA/ATPA. TGA/CD were associated with human leucocyte antigen (HLA) DR3-DQ2, with the DR3-DQ2/DR3-DQ2 genotype conferring the highest risk, followed by DR4-DQ8/DR4-DQ8. ATPA were associated with DR3-DQ2, DRB1*0404 (in males) and the DR3-DQ2/DR4-DQ8 genotype. TPOA were associated with the DR3-DQ2/DR3-DQ2 genotype. Almost one-quarter of patients diagnosed with T1D aged under 21 years have at least one other organ-specific autoantibody. HLA class II genetic profiling may be useful in identifying those at risk of multiple autoimmunity.

Serum IgE concentration and other immune manifestations of treatment with gold salts are linked to the MHC and IL4 regions in the rat

A subset of patients with rheumatoid arthritis occasionally develops skin reactions and glomerulonephritis and exhibits an increase in serum IgE concentration when treated with gold salts. Brown-Norway (BN) rats injected with aurothiopropanolsulfonate (ATPS) also manifest an autoimmune glomerulonephritis and increased serum IgE concentration, whereas Lewis (LEW) rats are resistant to complications. Here, we show linkage between responses to ATPS in a (BN x LEW) F2 cohort and the major histocompatibility complex (RT1) on rat chromosome 20 and between markers in the region of IL4 and other candidate genes on rat chromosome 10. Recently, human serum IgE concentration has been reported to be linked to the IL-4 region. Taken together, these findings raise the possibility that homologous genes could be implicated in ATPS manifestations in the rat and in the regulation of IgE levels in the human.

Evaluating the prevalence and opportunity for technology use in chronic kidney disease patients: a cross-sectional study

BACKGROUND

Chronic kidney disease (CKD) is increasing worldwide and early education to improve adherence to self-management is a key strategy to slow CKD progression. The use of the internet and mobile phone technologies (mHealth) to support patients is considered an effective tool in many other chronic disease populations. While a number of mHealth platforms for CKD exist, few studies have investigated if and how this population use technology to engage in self-management.

METHODS

Using a cross-sectional design across five health districts in Queensland (Australia), a 38-item self-report survey was distributed to adults with CKD attending outpatient clinics or dialysis units to measure current use and type of engagement with mHealth, perceived barriers to use, and opportunities to support CKD self-management. Odds ratio (OR) were calculated to identify associations between demographic characteristic and mHealth use.

RESULTS

Of the 708 participants surveyed, the majority had computer access (89.2%) and owned a mobile phone (83.5%). The most likely users of the internet were those aged ≤ 60 years (OR: 7.35, 95% confidence interval [CI]: 4.25-12.75, p < 0.001), employed (OR: 7.67, 95% CI: 2.58-22.78, p < 0.001), from non-indigenous background (OR: 6.98, 95% CI: 3.50-13.93, p < 0.001), or having completed higher levels of education (OR: 3.69, CI: 2.38-5.73, p < 0.001). Those using a mobile phone for complex communication were also younger (OR: 6.01, 95% CI: 3.55-10.19, p < 0.001), more educated (OR: 1.99, 95% CI: 1.29-3.18, p < 0.01), or from non-indigenous background (OR: 3.22, 95% CI: 1.58-6.55, p < 0.001). Overall, less than 25% were aware of websites to obtain information about renal healthcare. The mHealth technologies most preferred for communication with their renal healthcare teams were by telephone (56.5%), internet (50%), email (48.3%) and text messages (46%).

CONCLUSION

In the CKD cohort, younger patients are more likely than older patients to use mHealth intensively and interactively although all patients' technology literacy ought to be thoroughly assessed by renal teams before implementing in practice. Further research testing mHealth interventions to improve self-management in a range of patient cohorts is warranted.

HLA class II typing of whole genome amplified mouth swab DNA

Postal collection of mouth swabs provides a cheap and convenient means of DNA sampling but hitherto has not provided sufficient genetic material for HLA typing by polymerase chain reaction using sequence-specific primers (PCR-SSP). This study examined the feasibility of collecting mouth swabs from a test population by post, amplifying the DNA by whole genome amplification and genotyping for selected HLA class II alleles. We optimised a strategy for whole genome amplification or primer extension preamplification using a random 15 base pair primer which resulted in a 1,000-fold increase in DNA template. The amplified DNA was of sufficient quality for analysis of selected HLA Class II alleles by PCR-SSP and PCR using sequence-specific oligonucleotide probes. To test the reliability of our data, blood DNA from 30 individuals in 10 families, previously tested for all DRB1 alleles in a routine diagnostic laboratory, was then tested in our laboratory for DRB1 *03 and *04 following whole genome amplification. Further whole genome amplified product from another 10 families was tested for DRB1 *03, *04 in our laboratory and then tested for all DRB1 alleles in a routine diagnostic laboratory. One repeat typing was required to achieve 100% concordance between laboratories. Amplification of whole genome amplified DNA by PCR-SSP was then extended successfully to low-resolution HLA DRB1, DQA1, DQB1 and DPB1 typing. Mouth swab collection by post, followed by whole genome amplification of DNA provides an effective strategy for genetic analysis of large cohorts. We have optimised conditions for HLA class II typing on whole genome amplified DNA collected by mouth swab, but this method could potentially be applied to low concentrations of DNA from other sources.

Effects of type 2 cytokines on glomerular epithelial cells

Visceral glomerular epithelial cells (GECs) are involved in the maintenance of the filtration barrier and may play a role in immune responses. Cytokines may act on GECs and we wished to test this in vitro. Vascular endothelial growth factor (VEGF) is a specific product of the GEC that may play a role in glomerular permeability. We have investigated whether GECs in culture express receptors for interleukin (IL)-4, 10 and 13 (often grouped together as type 2 cytokines) and whether these cytokines alter GEC VEGF production. Type 2 cytokines were compared to transforming growth factor-beta (TGF-beta) and IL-1beta which are known to upregulate VEGF production. GECs were grown from human nephrectomy specimens and cultured with and without the addition of exogenous cytokines. Messenger RNA data demonstrated the presence of IL-4 receptor alpha, IL-10 receptor 1 and 2, and IL-13 receptors alpha1 and alpha2. However, at the protein level by flow cytometry, only IL-13 alpha2 could be consistently demonstrated. IL-4, IL-10 and IL-13 inhibited production of VEGF but did not affect the pattern of isoform expression. In contrast, TBF-beta and IL-1beta caused an increase in VEGF production. These effects were not explained by effects on proliferation. Our data provide evidence that GECs express receptors for type 2 cytokines and that these cytokines can act directly on GECs, to decrease VEGF production.

Autoantibodies to islet antigen-2 are associated with HLA-DRB1*07 and DRB1*09 haplotypes as well as DRB1*04 at onset of type 1 diabetes: the possible role of HLA-DQA in autoimmunity to IA-2

AIMS/HYPOTHESIS

To further our understanding of antigen presentation by HLA class II molecules, we have examined the influence of HLA class II genotype on expression of autoantibodies to islet antigen-2 (IA-2A).

METHODS

HLA class II genotype and IA-2A were determined within 3 months of diagnosis in 618 patients with type 1 diabetes (median age 11 years [range 0.7-20.9]). Antibodies to the juxtamembrane region of IA-2 were measured by a radiobinding assay in 481 of 484 IA-2A-positive patients.

RESULTS

IA-2A prevalence was highest in patients carrying at least one HLA-DRB1*04-DQA1*0301 (385 of 450; 86%), DRB1*07-DQA1*(0201 or 0301) (58 of 64; 91%) or DRB1*09-DQA1*0301 haplotype (18 of 19; 95%). Multiple regression showed that IA-2A were strongly associated with the number of these haplotypes carried; only 69 of 132 (52%) patients carrying none of these haplotypes had IA-2A, compared with 322 of 391 (82%) patients with one and 93 of 95 (98%) with two of these haplotypes (p < 0.001). IA-2 juxtamembrane antibodies were less frequent in IA-2A-positive patients with one (35%) or two (36%) DRB1*03-DQB1*02 or DRB1*07-DQB1*02 haplotypes than in those negative for these haplotypes (52%) (p = 0.002), but showed an independent positive association with IA-2A level (p < 0.001).

CONCLUSIONS/INTERPRETATION

HLA class II alleles strongly influence the prevalence of IA-2A. The high IA-2A prevalence in patients carrying DRB1*04, DRB1*07 and DRB1*09 alleles in linkage disequilibrium with DQA1*0301 or the closely related DQA1*0201 suggests the humoral response to IA-2 may be driven by HLA-DQA1 genes.

Cloning of a partial cDNA for rat interleukin-12 (IL-12) and analysis of IL-12 expression in vivo

Experimental models of autoimmunity in the rat may feature selective activation of either the Th1 or Th2 subset of helper T cells. Interleukin-12 (IL-12) is a key cytokine in the development of Th1 responses. In order to study IL-12 in the rat we used polymerase chain reaction (PCR) primers based on murine IL-12 to amplify a partial cDNA from rat tissue. The product was cloned and sequenced: it shows 94% nucleotide identity with the murine gene and 94% identity of predicted amino acid sequence. Primers based on the rat IL-12 sequence were used to analyse IL-12 expression in vivo using semi-quantitative PCR. We studied RNA from lymphoid tissues of two rat strains which differ in their response to mercuric chloride (HgCl2): Brown Norway (BN) rats develop autoimmunity with a predominant Th2 response; Lewis rats are resistant. Interleukin-12 expression was higher in Lewis than BN, and higher in spleen than lymph node. After HgCl2, IL-12 expression increased in BN towards the time when the autoimmune response autoregulates. Variation in baseline levels of IL-12 expression may account for the Th2 predisposition of BN rats compared to Lewis rats; IL-12 may play a role in the autoregulation of the Th2 response induced by HgCl2.

Characteristics of effective interventions supporting quality pain management in Australian emergency departments: an exploratory study

BACKGROUND

It is well established that pain is the most common presenting complaint in Emergency Departments. Despite great improvements in available pain management strategies, patients are left waiting for longer than 60min for pain relief on arrival to the emergency department. The aim of this study was to describe interventions that lead to successful implementation of the National Health and Medical Research Council approved guidelines Acute Pain Management: Scientific Evidence (2nd Edition) that include specific recommendations for best practice pain management.

METHODS

A two-phased, mixed-method, exploratory study of all 52 Australian hospital emergency departments participating in the National Emergency Care Pain Management Initiative incorporating interview and document analysis was undertaken.

FINDINGS

Interventions used by clinicians to improve pain management included nurse initiated analgesia, intranasal fentanyl for paediatric patients and lignocaine, and facio illiaca block. Education formed a major part of the intervention and the development of a working group of key stakeholders was critical in the successful implementation of change. Staff perceptions of patients' pain level and attitudes toward pain assessment and pain management were identified as barriers.

CONCLUSION

This study highlighted how an effective framework to plan and implement practice change and tailored interventions, including education and training systems and products using the best available evidence, best equipped clinicians to manage pain in the ED.

Diabetes in the parents of children with Type I diabetes

AIMS/HYPOTHESIS

Previous studies have reported an excess of Type II (non-insulin-dependent) diabetes mellitus in parents of children with Type I (insulin-dependent) diabetes mellitus. We set out to characterise the clinical and immunogenetic features of diabetes in parents of affected children, and to test the hypothesis that there is no excess of Type II diabetes within this population.

METHODS

Clinical details were collected from 3164 parents of 1641 children with Type I diabetes participating in the Bart's-Oxford study of childhood diabetes. Islet cell antibodies, antibodies to GAD and IA-2, and HLA class II genotype were determined in a subset of this group. Individuals were assigned a classification of Type I diabetes on the basis of clinical features and measurement of islet autoantibodies.

RESULTS

Of 184 parents with diabetes, 138 (75 %) were on insulin. At least one islet autoantibody was detected in 90 (59 %) of 152 parents tested, and of 116 who were HLA-typed, 23 (20 %) had the highest risk genotype HLA-DRB1(*)03-DQA1*0501-DQB1(*)0201 / DRB1*04-DQA1(*)0301-DQB1*0302. Of 46 non-insulin-treated parents, 12 had islet autoantibodies. Of all parents, 141 (4.5 %) were therefore classified as having Type I diabetes, and 31 (0.98 %) as Type II diabetes; 12 could not be classified because of missing data or samples.

CONCLUSION/INTERPRETATION

Autoimmune diabetes can present late and without immediate need for insulin treatment in parents of children with the disease. Previous studies have categorised this as Type II diabetes. Our study suggests that there is no excess of non-autoimmune diabetes in the families of children with Type I diabetes.

Gold and D-penicillamine induce vasculitis and up-regulate mRNA for IL-4 in the Brown Norway rat: support for a role for Th2 cell activity

D-penicillamine (DP) and gold salts which are used as immune-modulating agents in the treatment of rheumatoid arthritis are known to be capable of causing autoimmune manifestations. Most autoimmune diseases in man are dominated by Th1-type responses, and one might presume that effective immunotherapy counteracts Th activity, perhaps by causing a shift to a Th2 response. The mechanism of action of gold and DP is not clear, but some clues may be obtained from their effects in animal models. DP, gold salts and mercuric chloride (HgCl2) are known to induce Th2-dominated autoimmune syndromes in genetically susceptible rodent strains, and we have demonstrated recently that HgCl2 up-regulates messenger RNA (mRNA) for IL-4 in the Brown Norway (BN) rat. In the BN rat HgCl2 treatment is also associated with the development of vasculitis, and anti-myeloperoxidase (MPO) antibodies are found in the serum. The present study examined and confirmed the hypothesis that, since gold and DP induce an autoimmune syndrome similar to HgCl2 in the BN rat, they may also induce vasculitis and an up-regulation in mRNA for IL-4. Tissue injury was assessed macroscopically and histologically on day 5 and day 15 after the start of injections with gold, DP or HgCl2, serum titres of IgE and presence of anti-MPO antibodies were determined using ELISA, and a semi-quantitative assay using reverse transcription-polymerase chain reaction was used to assay the level of mRNA for IL-4 in spleen and caecum. The relative degree of tissue injury reflected the potency of induction of IgE by the three agents (HgCl2 being most potent and DP least potent). The lesions were identical histologically, supporting the premise that the vasculitis is a manifestation of the autoimmune syndrome rather than non-specific HgCl2 toxicity. Both gold and DP induced less up-regulation of mRNA for IL-4 than HgCl2. HgCl2 (but not gold or DP) induced anti-MPO antibodies. It would be interesting to examine patients treated with gold and DP to see if there is evidence of a Th2-type response in those developing autoimmune complications, and whether or not the bias to a Th2 environment contributes to efficacy of treatment of the underlying disease.

Soluble L-selectin levels in type I diabetes mellitus: a surrogate marker for disease activity?

L-selectin (CD62L) is a cell adhesion molecule which plays a key role in the initiation of leucocyte migration from blood vessels to sites of local inflammation. The aim of this study was to investigate T-lymphocyte expression of CD62L antigen and serum levels of soluble L-selectin (sL-selectin) in subjects with clinical and preclinical type I diabetes to determine whether they could provide surrogate markers for disease activity. CD62L selectin expression on memory T lymphocytes was studied by cytometric analysis in 22 patients with newly diagnosed type I diabetes, 20 first-degree relatives of patients with type I diabetes, 14 patients with Graves' disease, and 22 healthy controls. sL-selectin levels were measured by enzyme-linked immunosorbent assay (ELISA) in enlarged groups of subjects in these categories, as well as in patients with long-standing type I diabetes, treated Graves' disease and type II (non-insulin dependent) diabetes. L-selectin levels were also related to islet autoantibodies, human leucocyte antigen (HLA) genotype and L-selectin T668C gene polymorphisms. L-selectin expression on memory T lymphocytes was reduced in newly diagnosed diabetes and islet autoantibody positive siblings compared with controls. sL-selectin levels were significantly raised in newly diagnosed type I diabetes compared with controls, with intermediate levels in family members, both with and without islet autoantibodies, and in long-standing type I diabetes. Levels were also raised in patients with untreated Graves' disease. Patients with type II diabetes had sL-selectin levels which did not differ from controls. sL-selectin levels correlated with the presence of diabetes-associated HLA alleles in both family members and controls; levels also fell with increasing age in family members. Multiple regression analysis showed that HLA genotype and age were independent determinants of sL-selectin levels. sL-selectin levels are raised at the time of diagnosis of type I diabetes and Graves' disease and appear to be modulated by disease activity, but levels are determined predominantly by HLA-associated genetic susceptibility and age. sL-selectin may provide a late marker of autoimmune destruction of islets and sequential measurement may be useful in monitoring disease activity and the effect of interventions preceding type I diabetes.

The prevalence of insulin autoantibodies at the onset of Type 1 diabetes is higher in males than females during adolescence

AIMS/HYPOTHESIS

The incidence of Type 1 diabetes shows little sex bias up to age 15 years, but more males are diagnosed in early adult life. Humoral responses to the beta cell antigen insulin could help to reveal the mechanism underlying this difference. We therefore determined the influence of sex on the prevalence of insulin autoantibodies (IAA) at diagnosis.

METHODS

IAA were measured by radiobinding assay in 598 patients with newly diagnosed Type 1 diabetes (aged 10.5, range 0.8-20.7 years, 333 male), and analysed according to age, sex and HLA class II genotype.

RESULTS

Overall, 74% of males and 65% of females had IAA above the 97.5(th) centile of 2860 schoolchildren ( p=0.028). IAA prevalence was similar in males and females under the age of 15 (0-4 yr, 95% vs 88%; 5-9 yr, 76% vs 73%; 10-14 yr, 67% vs 58%), but male excess was seen between 15 and 21 years (66% vs. 32%, p(corr)=0.016). HLA class II genotype was available for 426 patients. IAA prevalence in DR4 homozygous patients was 87%, in DR4 heterozygous patients 72% and in DR4 negative patients 55% ( p<0.001). Multivariate analysis showed independent association of IAA with age ( p<0.001), number of DR4 alleles ( p<0.001) and male sex ( p=0.002).

CONCLUSIONS/INTERPRETATION

The prevalence of IAA in patients with newly diagnosed Type 1 diabetes is higher in males than females between 15 and 21 years of age. The lower prevalence of IAA in adolescent females implies sex-specific modulation of the autoimmune process during puberty.