Diabetic Siblings Research Articles

CD4 CD25 T Cells in Children with Recent Onset Type 1 Diabetes

Abstract Background: Type 1 diabetes (T1D) results from T-cell-mediated autoimmune destruction of the insulin-producing pancreatic islet Beta cells. This breakdown of immunological self-tolerance results in auto reactivity to islet self-antigens. This requires genetic susceptibility as well as environmental factors (gene environmental interaction). It is believed that numerical and functional balance between killer cells (CD4+ and CD8+) and regulatory T-cells in the pancreatic infiltrate determines the extent of Beta cell destruction. Aim of Study: To study the number and function of Treg CD4+ CD25+ T-cells in infants and children with recent onset type 1 diabetes and to compare the results with the Treg CD4+ CD25+ T-cells in the siblings of the diabetic child and control subjects. Patients and Methods: This study was performed on60 patients meeting the diagnostic criteria of type I diabetes, together with 20 children of their non diabetic siblings were recruited at the Diabetes Endocrine and Metabolism Pediatric Unit (DEMPU) at Cairo University Children’s Hospital in the period from December 2011 to October 2012. In addition to 20 children with age and sex-matched, none of whom had either a personal or family history of diabetes or other autoim-mune pathologies as control were included in the study. Results: Show no statistically significant relation of CD4 CD25 T-lymphocytes to age, anthropometric measures (weight & height), laboratory data including HBA1C, lipid profile or thyroid function tests, the insulin dose and the severity of the case presentation (whether classic onset or DKA). Also there was no statistically significant difference between the 3 groups (diabetic – non diabetic siblings – controls) regarding CD4CD25 T- lymphocytes levels by the one-way ANOVA test. Conclusion: The sensitivity of CD4 CD25 T-lymphocytes in case of type 1 diabetes was 60% and the specificity was 47%. The PPV (positive predictive value) and the NPV (neg-ative predictive value) were 55% and 67% respectively. Such results conclude that CD4 CD25 T-lymphocytes cannot be taken as a valid marker in case of type I diabetes.

A family harboring an MLKL loss of function variant implicates impaired necroptosis in diabetes

Maturity-onset diabetes of the young, MODY, is an autosomal dominant disease with incomplete penetrance. In a family with multiple generations of diabetes and several early onset diabetic siblings, we found the previously reported P33T PDX1 damaging mutation. Interestingly, this substitution was also present in a healthy sibling. In contrast, a second very rare heterozygous damaging mutation in the necroptosis terminal effector, MLKL, was found exclusively in the diabetic family members. Aberrant cell death by necroptosis is a cause of inflammatory diseases and has been widely implicated in human pathologies, but has not yet been attributed functions in diabetes. Here, we report that the MLKL substitution observed in diabetic patients, G316D, results in diminished phosphorylation by its upstream activator, the RIPK3 kinase, and no capacity to reconstitute necroptosis in two distinct MLKL−/− human cell lines. This MLKL mutation may act as a modifier to the P33T PDX1 mutation, and points to a potential role of impairment of necroptosis in diabetes. Our findings highlight the importance of family studies in unraveling MODY’s incomplete penetrance, and provide further support for the involvement of dysregulated necroptosis in human disease.

Diabetic Family History is Associated with Severity of Peripheral Neuropathy

Background Clinicians lack tools to determine a patient’s risk for diabetic peripheral neuropathy (DPN). This study examined the relationship between severity of DPN and family history of diabetes and DPN. Methods The Michigan Neuropathy Screening Instrument (MNSI) was used to collect symptom and physical exam data from consenting diabetic and control (n=293) patients. Family history of diabetes, DPN and major complications were collected going back two generations. Relevant additional characteristics were mined from patient medical records. Results Between patients who did and did not meet MNSI criteria for neuropathy, there were significant differences in comorbidities, including cardiac ( P <.0001), renal (P =.006), PVD (P<.0001), and thyroid (P =.027). Patients with history of diabetes on both sides (P=.032) or siblings (P<.0001); history of neuropathy on their maternal (P=.026), paternal (P=.002), both sides (P=.002) or siblings (P=.002); history of amputations on their maternal (P=.039) or paternal side (P=.162); or a history of ulcers on their maternal side (P=.030), paternal side (P=.005) or both sides (P=.046) were more likely to meet MNSI criteria for neuropathy. MNSI criteria for neuropathy was independently associated with history of cardiac or PVD comorbidities, and an MNSI score in the upper quartile was associated with diabetic siblings (OR=10.96). Conclusion: Family history of diabetes, DPN, and major complications was associated with neuropathy and also stronger degree of neuropathy. Family history, specifically diabetic siblings, cardiac and PVD comorbidities are independent risk factors for developing DPN. Clinicians should gather detailed family history and relevant comorbidities to optimize prevention of severe DPN in diabetics. Keywords:Type 2; Diabetic peripheral neuropathy; Family history of diabetes; MNSI; Complications

SAT-669 CD40 Ligand Gene Mutation in Type 1 Diabetes Mellitus in a Saudi Consanguineous Family

Introduction:Type 1 Diabetes Mellitus (T1D) is a common autoimmune disorder. Investigating genetic factors that could turn the immune cells to auto-reactive are critical to our understanding of T1D. In this study genetic factors and the affected autoimmunity related molecular mechanisms in familial T1D with parental consanguinity were studied.Materials and Method:Whole Exome Sequencing (WES) was performed in a family with familial T1D. Sanger Sequencing was done to analyze segregation in affected and non-affected. Clinical and molecular aspects were also evaluated. Protein modeling and other in silico tools were used to identify probable impact of genetic abnormalities on the structure and function of protein.Result:We identified a novel homozygous substitution mutation at “c.379A>T:p.Iso127Val” in CD40 Ligand (CD40LG) gene in diabetic siblings by WES. This change was found to be segregating in the affected and non-affected individuals by Sanger sequencing. Parents and non-diabetic siblings were found to be heterozygous carriers of the nucleotide change. The c.379A>T is located within evolutionarily conserved locus of human genome. Functional prediction by Gene Ontology term analysis suggested that immune functions of CD40LG are compromised by this genetic change. Further, by protein-modeling analysis we identified that structure of ligand-binding domain of CD40LG protein, with which it interacts with other immune cells, may also be affected. In silico analysis revealed significantly reduced spatial inter amino acid distance between the site of genetic change and the ligand binding domain in mutant CD40LG.Discussion:Apoptotic elimination of developing auto-reactive T-cells, having the potential to generate an autoimmune response against pancreatic cells, is critical to prevent T1D. This apoptotic removal mechanisms, occurs in thymus and is dependent on highly specific interaction of cell surface molecules as CD40LG on developing T-cells, and the corresponding cell surface molecules on Antigen Presenting Cells (APC). In the diabetic individuals investigated in our study, the mutation in CD40LG gene, caused significant structural damage to its protein, due to which these interactions between mutant CD40LG (present on T-cells) and the corresponding CD40 (present on APC) were probably affected. This loss of interaction between CD40LG bearing T-cells and APC, probably led to escape of auto-reactive T-cells in to immune system, which further generated autoimmune response against the pancreatic tissue, precipitating to T1D among these individuals.ConclusionGenetic investigation of cell surface proteins in autoimmune cells and understanding their mechanism for development of autoimmunity offers prospects for the development of new therapeutic strategies in the approach to probable early diagnosis of T1D.

Whole-Genome Sequencing of Finnish Type 1 Diabetic Siblings Discordant for Kidney Disease Reveals DNA Variants associated with Diabetic Nephropathy.

Several genetic susceptibility loci associated with diabetic nephropathy have been documented, but no causative variants implying novel pathogenetic mechanisms have been elucidated. We carried out whole-genome sequencing of a discovery cohort of Finnish siblings with type 1 diabetes who were discordant for the presence (case) or absence (control) of diabetic nephropathy. Controls had diabetes without complications for 15-37 years. We analyzed and annotated variants at genome, gene, and single-nucleotide variant levels. We then replicated the associated variants, genes, and regions in a replication cohort from the Finnish Diabetic Nephropathy study that included 3531 unrelated Finns with type 1 diabetes. We observed protein-altering variants and an enrichment of variants in regions associated with the presence or absence of diabetic nephropathy. The replication cohort confirmed variants in both regulatory and protein-coding regions. We also observed that diabetic nephropathy-associated variants, when clustered at the gene level, are enriched in a core protein-interaction network representing proteins essential for podocyte function. These genes include protein kinases (protein kinase C isoforms ε and ι) and protein tyrosine kinase 2. Our comprehensive analysis of a diabetic nephropathy cohort of siblings with type 1 diabetes who were discordant for kidney disease points to variants and genes that are potentially causative or protective for diabetic nephropathy. This includes variants in two isoforms of the protein kinase C family not previously linked to diabetic nephropathy, adding support to previous hypotheses that the protein kinase C family members play a role in diabetic nephropathy and might be attractive therapeutic targets.

Prediction of Insulin Resistance with Anthropometric Measures in Adolescence

In regions of higher incidence of diabetes, more frequent screening is recommended to improve diabetes management and to initiate prevention strategies. Some developed countries screen Obese children with higher BMI with oral glucose tolerance test each year. There is a need to validate use of anthropometric measures for screening and early detection of subjects who are at risk of developing diabetes. We hypothesized that normoglycemic young adult who are siblings of diabetics or obese subjects are genetically predisposed & they are known to have a higher substantial heritable component of insulin resistance than the siblings of non-diabetics. This study evaluated simple anthropometric measures that will be optimally required to predict insulin resistance in normoglycemic. Siblings of Diabetics were obese compared to siblings of non diabetics. Siblings of diabetics had higher BMI and Waist circumference with significantly lower IS values & higher IR values. It was observed that ISI 0–120 indices showed a significantly better correlation with compared to HOMA IR in siblings of diabetics in both first & second degree relatives. ISI0–120 values were significantly lower in Siblings of Diabetics with higher BMI, longer Waist circumference. Significant correlation with clinical measures like BMI & waist circumference was observed. BMI 24 there were 30 subjects.

Insulin sensitivity index (ISI 0-120) from oral glucose tolerance test in healthy young adults

Background: Insulin sensitivity (IS) is the body’s systemic responsiveness to glucose and it is the measure of the ability of endogenous insulin to reduce the glucose in extracellular fluids by inhibition of gluconeogenesis and increase peripheral glucose uptake. IS reflects on the efficiency of insulin in response to glucose intake in the body. In diabetics, IS subjects are interpreted to require smaller amounts of insulin to lower blood glucose levels than someone who has low sensitivity. There is a need to detect insulin resistance (IR) in the pre-disease state, i.e., before the onset of impaired glucose tolerance (IGT). Early detection of IR or decreased IS in healthy subjects before the onset of IGT is of importance as it facilitates implementation of preventive measures in subject with such high risk. Aims and Objectives: The objective of the study is detect early occurrence of low Insulin Sensitivity in healthy young adults, using Insulin Sensitivity Index derived from OGTT. Materials and Methods: A total of 80 healthy volunteers in the age group of 18-25 years were recruited for the study, 40 subjects were siblings of diabetics and 40 subjects were siblings of non-diabetics (SND) a standard (75 g) OGTT was performed for the study. Blood samples for determination of plasma glucose and insulin levels drawn at 0 (fasting), 30, 120 min after glucose solution ingestion. Assays of fasting (basal), 30, 120 min venous plasma glucose during OGTT was performed with glucose oxidase method on site using glucose auto analyzer. The serum plasma was stored at −20°C until assayed. Corresponding specific insulin concentration was determined using radioimmunoassay (RIA) with human specific antibody RIA kit IS was calculated using physiological OGTT based mathematical models. QUICKI was derived for fasting insulin and fasting glucose values. ISI 0-120: Uses OGTT values, using only 0 and 120 min post-glucose challenge insulin and glucose concentrations. The reference values for various IR and IS indexes for our urban population with normal OGTT (n = 79) are QUICKI = 0.31 (0.20-0.52) sibling of diabetics (SD) - 0.07, ISI 0-120 = 63.62 (27.37-134.79) SD - 22.71. We observed that SD had significantly lower IS indices ISI 0-120 (56.27, P < 0.002) and a trend toward significance for QUICKI (0.29578, P < 0.056). Results: We observed that the mathematical models ISI 0-120 to be a fairly reliable tool for assessment of IS in normoglycemic young adults, compared to QUICKI. ISI 0-120 take into consideration the all the parameters of the 2 h OGTT glucose and also includes insulin into consideration for evaluation. Simple OGTT based mathematical models can be used as a reasonable alternative to measure IS or IR instead of the cumbersome glucose clamp or other expensive techniques in epidemiological or general clinical settings. Conclusion: Detection of IR in pre-disease condition in healthy individuals, allows the physician to initiate preventive measures, such as lifestyle modification, diet and exercise, thereby preventing the high-risk subjects from progressing to disease state.

HLA-DRB1typing among Type I Diabetic Patients and their First Degree relatives in a Comparative Study

Background: The genetic susceptibility to IDDM maps to the MHC class II region, thus one approach to investigating the immunopathogenesis of diabetes is to study first degree relatives of affected individuals. Objectives: To detect the inherited relationship between (HLA-DRB1) allels and type one Diabetic mellitus. Methodology: A case-control study was performed on 90 persons, they divided into three group which are diabetic, siblings and control (30 persons in each group), who attended to Al Zahraa Teaching Hospital /Diabetic Center in Al Kut/Iraq between the period of April; 2012 till April; 2013.data was analyzed by using SPSS 16th version. Distribution of HLA-DRB1 loci among the study groups (type 1 Diabetic patients, Siblings and Control group) were performed using MR.SPOT ROBOTING system. Results: results showed that the frequencies of HLA-DRB1*3,*4 {25 (69.4%)} among Diabetic group were Significant (P value = 0.002), in compare to the corresponding frequencies among control group {11 (30.6%)}, in compare to the frequencies of other HLA-DRB1 loci in both Diabetic group and Control group { 15 (34.1%), 29 (65.9%)} respectively. Meanwhile results have showed that there were no Significant (P value = 0.116), in the frequencies of HLA-DRB1*3,*4 {25 (58.1%)} among Diabetic group in compare to the frequencies of HLA-DRB1*3,*4 {18 (41.9%)} among Siblings group, in compare to the frequencies of other HLA-DRB1 loci among Diabetic group and Sibling group {15 (40.5%), 22 (59.5%)} respectively, also results have showed that there were no Significant (P value = 0.104), in the frequencies of HLA-DRB1*3,*4 {18 (62.1%)} among Sibling group in compare to the frequencies of HLA-DRB1*3,*4 {11 (37.9%)} among Control group, in compare to the frequencies of other HLA-DRB1 loci among Sibling group and Control group {22 (43.1%), 29 (56.9%)} respectively. conclusion: In conclusion there were a genetic predisposition of diabetic Siblings for development of Diabetes since, both Diabetic group and Sibling group showing the highest frequencies of HLA-DRB1 *3,*4, in compare to Control group. Recommendation: larger sample group are required to include other allels

Oral Glucose Tolerance Test (OGTT) among type 1 diabetic Siblings and Control group

Background: the genetic factor of type 1 diabetes mellitus may play a key role in pathogenesis of that disorder, thus, diabetic siblings might prone into an impaired OGTT. Objective: To determine whether diabetic Siblings might have an impaired glucose tolerance test in compare to normal control group. Methodology: A case-control study was performed on 120 persons, they divided into three group which are diabetic, siblings and control (40 persons in each group), who attended to Al Zahraa Teaching Hospital /Diabetic Center in Al-Kut between the period of April; 2012 till April; 2013. Results: OGTT performed on both diabetic siblings and control, results have showed that the Means of OGTT is highly Significant (P value = 0.000) in both Siblings and Control groups, whereas there were no Significant differences in the Means of differences of OGTT in both tested groups (Siblings and Control), P value = 0.288, although the Mean of differences of OGTT is higher in Siblings group (25.3250) than that in Control group (22.0750). Conclusion: the inheritance factor play a key role in pathogenesis of type 1 diabetes mellitus since, diabetic siblings showed an impaired OGTT. Recommendation: for early detection of diabetes, diabetic siblings must submit to a routine screening test by OGGT.

Digital diabetes?

S Yohannes, et al. Dermatoglyphics in diabetes: a prospective diagnostic aid and early preventive tool. Pages 50– 51. We have friction ridges on the skin of our finger tips – our fingerprints. These develop on the smooth fetal volar pads. The patterns formed vary according to the rate of hand growth versus volar pad regression. Genetic factors influence the timing of these events and thus the ultimate fingerprint pattern, so family members, particularly identical twins, share a similar pattern type. However, in each person the exact arrangement of the friction ridges and any subsequent scarring mean that their fingerprints are unique. Intrauterine undernutrition has been linked to adult type 2 diabetes1 which is often strongly inherited, so it seems logical to consider if fingerprints, also influenced by these factors, can be used as a marker for risk of future diabetes. In people born during the Dutch hunger period (1943–47), with adjustment for age, sex, parental diabetes and adult anthropometry, fingerprint mean dermatoglyphic ridge count difference between fingertips 1 and 5 (Md15) was associated with prevalent diabetes odds ratio of 1.37 (1.02–1.84). ‘Among 42 sibling pairs discordant for diabetes, the diabetic sibling had higher Md15 by 3.5 (0.6–6.3) after multivariable adjustment.’2 However, many paths lead to diabetes, with different genetic factors and different effects of nutrition inside or outside the womb. There are probably hundreds of versions of diabetes. So, in this issue of Practical Diabetes, Yohannes et al. are right to point out that very carefully controlled studies are needed. Patients have a practical issue: ‘I had to have my fingerprints done recently. The guy was all cheery and polite… until I had to show him my hands. He asked what all the “dots” on my left hand fingers were from so we had a little conversation about diabetes, the pump, testing… Then, he says, “oh, well that's going to make the prints bad and there's nothing I can do about it. The prints probably won't turn out and you'll have to come back up here to do it again”.’3 Small scars on the fingertips should not invalidate fingerprint testing; indeed, it may make people more readily identifiable!

English

As the prevalence of lipoprotein abnormalities in adolescents is increasing dramatically, the identification of relevant risk factors is a major public health challenge. The aim of this study was to investigate whether a family history of diabetes could be a risk factor for lipid abnormalities in healthy individuals. This study is a cross-sectional case control study.&nbsp;179&nbsp;men and women were studied in two equal-member groups (with diabetic parents&#39; background and without any diabetic sibling). Both groups matched in body mass index (BMI), age and sex. The serum concentration of oxidized-low density lipoprotein (LDL), Apo B100 and insulin were measured by enzyme linked immunosorbant assay technique and TG, Chol, HDL-C, FBS and GTT by enzymatic methods.&nbsp;The LDL-C level was calculated using the Friedewald formula.&nbsp;The results show that there&nbsp;were&nbsp;no significant variation in the amount of plasma FBS, GTT, Cho, TG, LDL and HDL between&nbsp;thetwo groups, whereas a significant increase was found in&nbsp;the&nbsp;amount of insulin (P = 0.02),&nbsp;Apo B100 (P = 0.001), OX-LDL (P = 0.001) and HOMA-IR (P = 0.03) in the case group as compared to the control group. We conclude that a family history of diabetic parents can lead to lipid parameters abnormalities and CVD risk factor via aggregation of inherited defected genes. &nbsp; Key words:&nbsp;Diabetes, oxidized-low density lipoprotein (LDL), Apo B100, lipoproteins.

Hyperinsulinaemia Insulin Resistance and Cardiometabolic Risk Profile in Siblings of Type 2 Diabetics

Objective: To compare non-diabetic siblings of Type 2 diabetics for insulin resistance, hyperinsulinaemia, dyslipidemia and biometric indices with non diabetic volunteers with no family history of diabetes. Study Design: Cross sectional analytical study. Place and Duration of Study: A tertiary care teach-ing institution during Dec.2009 to July 2010. Methodology: Siblings of type 2 diabetics above the age of 25 years were matched as closely as possible for age, sex socioeconomic conditions with non diabe-tic volunteers with no family history of diabetes. Both groups were compared for fasting serum insulin, glu-cose, lipid levels and biometric indices using independent t-test. Insulin resistance was calculated by the Quicki (Quantitative insulin check index) method with cutoff at 0.34 on R.O.C analysis. Results: The 106 non diabetic siblings of Type 2 dia-betes mellitus (Group 1) with a mean age of 40.8 ± 12.1 years p value 0.13 were compared to 106 non dia-betic volunteers (Group 2) mean age 43.5 ± 14.2 years. Out of a total of 212 participants 20 (9.4%) subjects had hyperinsulinaemia (mean serum insulin15.69 ± 6.02 µU/L p < 0.001) and insulin resistance (90% sen-sitivity CI 86 to 94, 98.96% specificity CI 97.7 to 100) and all belonged to group 1. A further comparison of the above variables was made within group 1 between 20 (9.4%) insulin resistant siblings and 86 (90.6%) non insulin resistant siblings. The insulin resistant sib-lings showed significant increase in HbA 1 c 7.02% ± 1.5 vs 6.2% ± 1.49 p = 0.008, BMI 30.4 ± 6.4 kg/m 2 vs. 27.1 ± 4.7 kg / m 2 p = 0.01and Serum insulin levels 15.92 ± 6.11 vs. 4.57 ± 2.38 p < 0.001. Conclusion: The study suggests that siblings of dia-betics are a special group who have hyperinsulinemia, insulin resistance and obesity and are at high risk for developing type 2 diabetes. Key words: Hyperinsulinaemia, insulin resistance, BMI, siblings, metabolic syndrome.

Relationship among sera lipoprotein abnormalities in healthy individuals with background of diabetic sibling

Relationship among sera lipoprotein abnormalities in healthy individuals with background of diabetic sibling

Assessment of insulin resistance in normoglycemic young adults

Detection of Insulin resistance (IR) in normoglycemic young subjects before the onset of Impaired Glucose Tolerance (IGT) is of importance as it affords implementation of preventive measures in such high risk subject. Very few studies have specifically evaluated for the presence of IR in younger age group with normal glucose tolerance. The gold standard for investigating and quantifying insulin resistance is the "hyperinsulinemic euglycemic clamp," the complicated nature of the "clamp" technique, alternatives have been sought to simplify the measurement of insulin resistance. The oral glucose tolerance test (OGTT) is one of the most commonly used methods to evaluate whole body glucose tolerance in vivo. IR & IS values of HOMA-IR, ISI 0-120, QUICKIE mathematical models derived from OGTT have been shown to produce equivalent results as in Euglycemic clamp technique we hypothesized that normoglycemic young adult who are siblings of type II diabetics (SD) probably have higher IR values than the siblings of non diabetics as they are genetically predisposed. In this study 79 normal young adult volunteers, 40 subjects with family history of diabetes (SD) and 39 subjects without family history of diabetes (SND), in the age range of 18 to 25 years were evaluated for Insulin resistance. Standard (75 g) OGTT was performed on all the study subjects after an overnight fast. Fasting (basal), 30, 120 min venous plasma glucose & Corresponding specific insulin concentration was determined by radioimmuno assay (RIA) using a human specific antibody RIA kit. In each subject, the degree of insulin resistance was estimated by various parameters of Insulin resistance & sensitivity that were calculated using physiological mathematical models like HOMA-IR, ISI0-120, IGI, QUICKIE and their formulas derived from OGTT. The mean age of the study population was 19.01 (18 to 25 years), Male: 33 (41.3%) and Female: 47 (58.8%). The normoglycemic subjects were categorized as Siblings of Diabetics (SD n = 40) and siblings of non-diabetics(SND n = 39). Both the groups were matched by physical, clinical and routine laboratory parameters and were not statistically significant different. Siblings of diabetics had a statistically significant higher values of insulin at baseline, 30 min & 120 minutes and glucose at 30 minutes. Siblings of diabetics had a significantly higher insulin resistance and lower insulin sensitivity indices as in HOMA-IR (2.01527, p < 0.017), ISIO-120 (56.27, p < 0.002) and I0/G0 ratio (0.122381, p < 0.012) and a trend towards significance for QUICKIE(0.29578, p < 0.056). Detection of insulin resistance in normoglycemic young adult subjects in pre-disease state is feasible using mathematical models like HOMA IR, ISIO-120 from OGTT. OGTT is simple and a generally acceptable test. Siblings of diabetics had higher Insulin resistance values and lower Insulin sensitivity values. Physiological models like HOMA IR, QUICKIE, I0/G0 ratio, IGI, ISIO-120 are simple & cost effective method for screening Insulin resistance. Diagnosis of Insulin resistance in pre-disease state allows initiation of preventive measures like life style modification, diet & exercise, thereby preventing the high risk subjects from progressing to disease state.

Type 1 Diabetic Children and Siblings Share a Decrease in Dendritic Cell and Monocyte Numbers but are Differentiated by Expansion of CD4+T Cells Expressing IL-17

Type 1 diabetes (T1D) is an autoimmune disease characterised by multiple defects of immune cells which allow the expansion of pathogenic β cell-specific T effector cells and subsequent T1D development. We performed immunomonitoring assays on blood immune cells in T1D children, their siblings and controls with the supposition that the results would elucidate the sequence of abnormalities in peripheral immune cells leading to the progression of autoimmunity from non-diabetic siblings to diabetic children. We assessed myeloid dendritic cell (MDC), plasmacytoid (P)DC, monocyte, CD4+T and CD8+T cell compartments, and cytokine expression in CD4+T cells and CD8+T cells, by polychromatic flow cytometry in erythrocyte-lysed fresh blood. The numbers of CD16+MDC, PDC and CD16+ monocytes were similarly decreased in diabetic children and their siblings. Whereas the numbers of CD16-CD141-MDC, CD16-CD141+MDC, CD16- monocytes, T naive (CD45RO-CD62L+), T central memory (CD45RO+CD62L+), T effector memory (CD45RO+CD62L-), T terminally-differentiated effector (CD45ROCD62L-) and T regulatory cells (CD4+CD25+127lo/- or CD4+Foxp3+ cells) were not affected in diabetic children or their siblings. Furthermore, analysis of cytokine expression in CD4+T cells and CD8+T cell revealed an increased proportion of CD4+T cells expressing IL-17, differentiating diabetic children from their non-diabetic siblings. Our data suggest that diabetic children and their siblings suffer a considerable reduction of blood immune cells involving CD16+MDC, PDC and CD16+ monocytes that may result from shared genetic or environmental factors. However, this reduction of blood immune cells requires combination with the proinflammatory cytokine IL-17 to allow disease expression in diabetic children.

Familial Clustering of Diabetic Retinopathy in Chongqing, China, Type 2 Diabetic Patients

To investigate whether there is familial aggregation of diabetic retinopathy (DR) among type 2 diabetes mellitus (T2DM) patients in Chongqing, the municipality in southwest China. From December 2004 to December 2006, 167 T2DM families with at least 2 diabetic siblings were investigated. In all 414 subjects, the sibling with the longest duration of diabetes was defined as the proband. The occurrence of retinopathy was compared between the siblings of probands with and without retinopathy. DR risk factors of the siblings of probands were studied by multiple logistic regression analysis. DR was diagnosed in 7.1% of the siblings of the probands without DR and in 29.7% of the siblings of the probands with DR. The difference reached statistical significance in probands with DR and probands without DR (p<0.0001). Nonesterified fatty acid (NEFA) was a risk factor for DR (odds ratio = 2.108, 95% confidence interval 1.077-4.127). It appeared that regardless of probands with DR, siblings with history of smoking had less risk for developing DR than those with no history of smoking. Familial clustering of DR existed in the patients with T2DM in Chongqing, China. In DR siblings, NEFA is a risk factor of DR, while smoking may reduce DR occurrence.

Combination Therapies for Type 1 Diabetes: Why Not Now?

Type 1 diabetes (T1D), often referred to as juvenile diabetes, is thought to be an autoimmune disease in which insulin-producing b-cells in the islets of Langerhans of the pancreas are being destroyed, resulting in hyperglycemia and the need for lifelong insulin injections. In addition to the impact on quality of life, life-threatening long-term complications can be caused by high blood sugar levels, which predominantly affect the vasculature, resulting in increased risk for heart attacks, strokes, kidney failure, blindness and reduced overall life expectancy. The disease is caused by a complex interplay of genetic and environmental factors and, since the precise cause is not known and the human pancreas is difficult to access, development of an immunotherapy has been slow. However, we have learned important lessons in recent years that should strongly impact upon future therapeutic decisions and, as proposed in this editorial, now lead us to prioritize testing the rationale of combination therapies in clinical trials. The foremost insight is that T1D, even after successful reversal with cyclosporine or nonmyeloablative stem cell therapy (both of which have considerable systemic side effects and, therefore, could not be applied as a generalized intervention) has the unfortunate tendency to recur [1,2]. This is due to the accumulation of b-cell antigen-specific memory T cells, which can expand and react more efficiently, as soon as b-cells are being augmented or reintroduced. This was elegantly demonstrated in recent islet transplantation trials in which the amount of preexisting autoimmune cells positively correlated with the rapidity of graft loss within 2–4 years [3]. In addition, earlier studies by Sutherland had demonstrated that islets within the pancreas of a nondiabetic twin transplanted into his diabetic sibling were destroyed within months by a recurrent autoimmune attack [4], demonstrating that even new syngeneic b-cells generated from autologous stem cells would be rapidly annihilated. These facts underline the need for devising a form of immunotherapy that can create longterm tolerance to b-cells while circumventing unacceptable side effects from chronic immunosuppression, most notably secondary cancers [5]. Thus, since there is little proof to date that a onetime resetting intervention can eliminate, control or decimate the autoreactive memory pool sufficiently, our options for monotherapies are rather limited at present [6].

A Gm haplotype study in relation with HLA-DR in 155 insulin-dependent diabetic patients and their affected and non affected siblings.

In order to assess interaction between HLA and Gm for susceptibility to IDDM, the families of 155 IDDM probands were typed for HLA class I, II, III antigens and 16 Gm allotypes (including G2m23). Haplotypes were obtained for both systems. Individuals bearing the equivocal haplotype Gm (formula; see text) were excluded. The frequencies of the 6 Gm haplotypes detected were comparable in IDDM patients, sibling controls and unrelated controls. The number of Gm haplotypes was compatible with random segregation whether or not the HLA genotype was taken into account. However, analysis of the HLA-DR allelic combinations showed an increase of the uncommon haplotype Gm (formula; see text) in IDDM patients bearing DR3 in the absence of DR4 (Gm (formula; see text) phenotype frequency 43% vs 24% in other allelic combinations, p less than 0.04). When 21 diabetic and 154 non diabetic siblings of the probands were compared, the combined presence of DR3/ non 4 and Gm (formula; see text) was observed in 7 (33%) affected and 11 (7%) unaffected siblings (p less than 0.001), conferring a relative risk of 6.4 to siblings who bear both markers. All DR3/non 4 positive affected siblings (7/7) also carried Gm (formula; see text) compared with 27% (11/41) of unaffected siblings (p less than 0.001). This result suggests, that in spite of the absence of segregation distortion, interaction between Gm and HLA gene products may play a role in the familial penetrance of IDDM.

Parental diabetes status reveals association of mitochondrial DNA haplogroup J1 with type 2 diabetes

BackgroundAlthough mitochondrial dysfunction is consistently manifested in patients with Type 2 Diabetes mellitus (T2DM), the association of mitochondrial DNA (mtDNA) sequence variants with T2DM varies among populations. These differences might stem from differing environmental influences among populations. However, other potentially important considerations emanate from the very nature of mitochondrial genetics, namely the notable high degree of partitioning in the distribution of human mtDNA variants among populations, as well as the interaction of mtDNA and nuclear DNA-encoded factors working in concert to govern mitochondrial function. We hypothesized that association of mtDNA genetic variants with T2DM could be revealed while controlling for the effect of additional inherited factors, reflected in family history information.MethodsTo test this hypothesis we set out to investigate whether mtDNA genetic variants will be differentially associated with T2DM depending on the diabetes status of the parents. To this end, association of mtDNA genetic backgrounds (haplogroups) with T2DM was assessed in 1055 Jewish patients with and without T2DM parents ('DP' and 'HP', respectively).ResultsHaplogroup J1 was found to be 2.4 fold under-represented in the 'HP' patients (p = 0.0035). These results are consistent with a previous observation made in Finnish T2DM patients. Moreover, assessing the haplogroup distribution in 'DP' versus 'HP' patients having diabetic siblings revealed that haplogroup J1 was virtually absent in the 'HP' group.ConclusionThese results imply the involvement of inherited factors, which modulate the susceptibility of haplogroup J1 to T2DM.

Risk Factors for Development and Progression of Diabetic Kidney Disease and Treatment Patterns Among Diabetic Siblings of Patients With Diabetic Kidney Disease

Risk Factors for Development and Progression of Diabetic Kidney Disease and Treatment Patterns Among Diabetic Siblings of Patients With Diabetic Kidney Disease