The rationale, design and baseline data of FLOW, a kidney outcomes trial with once-weekly semaglutide in people with type 2 diabetes and chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a common complication of type 2 diabetes (T2D). Glucagon-like peptide-1 receptor agonists (GLP-1RAs) improve glycaemic control and lower body weight in people with T2D, and some reduce the risk of cardiovascular (CV) events in those with high CV risk. GLP-1RAs might also have kidney-protective effects. We report the design and baseline data for FLOW (NCT03819153), a trial investigating the effects of semaglutide, a once-weekly (OW) GLP-1RA, on kidney outcomes in participants with CKD and T2D. METHODS: FLOW is a randomised, double-blind, parallel-group, multinational, phase 3b trial. Participants with T2D, estimated glomerular filtration rate (eGFR) ≥50‒≤75 ml/min/1.73 m2 and urine albumin:creatinine ratio (UACR) >300‒<5000 mg/g or eGFR ≥25‒<50 ml/min/1.73 m2 and UACR >100‒<5000 mg/g were randomised 1:1 to OW semaglutide 1.0 mg or matched placebo, with renin-angiotensin-aldosterone system blockade (unless not tolerated/contraindicated). The composite primary endpoint is time to first kidney failure (persistent eGFR <15 ml/min/1.73 m2 or initiation of chronic kidney replacement therapy), persistent ≥50% reduction in eGFR or death from kidney or CV causes. RESULTS: Enrolled participants (N = 3534) had a baseline mean age of 66.6 years [standard deviation (SD) 9.0], haemoglobin A1c of 7.8% (SD 1.3), diabetes duration of 17.4 years (SD 9.3), eGFR of 47.0 ml/min/1.73 m2 (SD 15.2) and median UACR of 568 mg/g (range 2‒11 852). According to Kidney Disease: Improving Global Outcomes guidelines categorisation, 68.2% were at very high risk for CKD progression. CONCLUSION: FLOW will evaluate the effect of semaglutide on kidney outcomes in participants with CKD and T2D, and is expected to be completed in late 2024.

Current and future therapies for type 1 diabetes.

In type 1 diabetes, insulin remains the mature therapeutic cornerstone; yet, the increasing number of individuals developing type 1 diabetes (predominantly children and adolescents) still face severe complications. Fortunately, our understanding of type 1 diabetes is continuously being refined, allowing for refocused development of novel prevention and management strategies. Hitherto, attempts based on immune suppression and modulation have been only partly successful in preventing the key pathophysiological feature in type 1 diabetes: the immune-mediated derangement or destruction of beta cells in the pancreatic islets of Langerhans, leading to low or absent insulin secretion and chronic hyperglycaemia. Evidence now warrants a focus on the beta cell itself and how to avoid its dysfunction, which is putatively caused by cytokine-driven inflammation and other stress factors, leading to low insulin-secretory capacity, autoantigen presentation and immune-mediated destruction. Correspondingly, beta cell rescue strategies are being pursued, which include antigen vaccination using, for example, oral insulin or peptides, as well as agents with suggested benefits on beta cell stress, such as verapamil and glucagon-like peptide-1 receptor agonists. Whilst autoimmune-focused prevention approaches are central in type 1 diabetes and will be a requirement in the advent of stem cell-based replacement therapies, managing the primarily cardiometabolic complications of established type 1 diabetes is equally essential. In this review, we outline selected recent and suggested future attempts to address the evolving profile of the person with type 1 diabetes.

Negligible impact of rare autoimmune-locus coding-region variants on missing heritability.

Genome-wide association studies (GWAS) have identified common variants of modest-effect size at hundreds of loci for common autoimmune diseases; however, a substantial fraction of heritability remains unexplained, to which rare variants may contribute. To discover rare variants and test them for association with a phenotype, most studies re-sequence a small initial sample size and then genotype the discovered variants in a larger sample set. This approach fails to analyse a large fraction of the rare variants present in the entire sample set. Here we perform simultaneous amplicon-sequencing-based variant discovery and genotyping for coding exons of 25 GWAS risk genes in 41,911 UK residents of white European origin, comprising 24,892 subjects with six autoimmune disease phenotypes and 17,019 controls, and show that rare coding-region variants at known loci have a negligible role in common autoimmune disease susceptibility. These results do not support the rare-variant synthetic genome-wide-association hypothesis (in which unobserved rare causal variants lead to association detected at common tag variants). Many known autoimmune disease risk loci contain multiple, independently associated, common and low-frequency variants, and so genes at these loci are a priori stronger candidates for harbouring rare coding-region variants than other genes. Our data indicate that the missing heritability for common autoimmune diseases may not be attributable to the rare coding-region variant portion of the allelic spectrum, but perhaps, as others have proposed, may be a result of many common-variant loci of weak effect.

FCGR3B copy number variation is associated with susceptibility to systemic, but not organ-specific, autoimmunity.

Naturally occurring variation in gene copy number is increasingly recognized as a heritable source of susceptibility to genetically complex diseases. Here we report strong association between FCGR3B copy number and risk of systemic lupus erythematosus (P = 2.7 x 10(-8)), microscopic polyangiitis (P = 2.9 x 10(-4)) and Wegener's granulomatosis in two independent cohorts from the UK (P = 3 x 10(-3)) and France (P = 1.1 x 10(-4)). We did not observe this association in the organ-specific Graves' disease or Addison's disease. Our findings suggest that low FCGR3B copy number, and in particular complete FCGR3B deficiency, has a key role in the development of systemic autoimmunity.

Robust associations of four new chromosome regions from genome-wide analyses of type 1 diabetes.

The Wellcome Trust Case Control Consortium (WTCCC) primary genome-wide association (GWA) scan on seven diseases, including the multifactorial autoimmune disease type 1 diabetes (T1D), shows associations at P < 5 x 10(-7) between T1D and six chromosome regions: 12q24, 12q13, 16p13, 18p11, 12p13 and 4q27. Here, we attempted to validate these and six other top findings in 4,000 individuals with T1D, 5,000 controls and 2,997 family trios independent of the WTCCC study. We confirmed unequivocally the associations of 12q24, 12q13, 16p13 and 18p11 (P(follow-up)

Early postoperative continuous glucose monitoring in pancreas transplant recipients.

Continuous glucose monitoring (CGM) is used in people with type 1 diabetes to help with insulin treatment regimens. Its value in whole-organ pancreas transplantation (PT) is largely unknown. This study aimed to use CGM to assess the metabolic profile of pancreas transplant recipients in the early post-transplant period. We studied CGM data in 30 PT recipients and related findings to an early oral glucose tolerance test (OGTT). Complete data were available for 26 recipients. Seven days after a PT, normoglycaemia was present 77.9% of the time. Hypoglycaemic events (glucose <3.9 mmol/l) occurred in 10 of 26 (38.5%) of the cohort, but were infrequent (present 1.4% of the time). Hyperglycaemia (glucose >7.8 mmol/l) was present for 20.7% of the study period and correlated with a diagnosis of abnormal glucose tolerance. Whilst normoglycaemia is successfully achieved for the majority of the time after PT, hypoglycaemia can occur. Hyperglycaemia is more common and correlates well with the early postoperative OGTT, which is associated with graft failure. CGM is easier to perform and provides 24-h data that could inform clinical decision-making in patients in the postoperative period.

Postoperative impaired glucose tolerance is an early predictor of pancreas graft failure.

AIMS/HYPOTHESIS: The management of pancreatic transplantation is limited by a lack of clinically relevant early markers of graft dysfunction to enable intervention prior to irreversible damage. The aim of this study was to assess the OGTT as an early predictor of pancreatic graft failure. METHODS: Patients with graft failure (return to insulin dependence) were identified from a prospectively maintained clinical database. Data from OGTTs performed within 2 weeks of the transplant were retrospectively collected for 210 subjects, 42 with graft failure (21 after simultaneous pancreas-kidney transplant and 21 after isolated pancreas transplant) matched to 168 with functioning grafts. The groups were compared to assess the relationship between early OGTT result and pancreas graft failure. RESULTS: Mean 2 h glucose from the OGTT was significantly higher in the overall graft failure group compared with the control group (8.36 vs 6.81 mmol/l, p = 0.014). When interpreted in combination with fasting glucose, abnormal glucose tolerance was more common in the failed graft group (50% vs 22%, p = 0.001). In an adjusted model, abnormal glucose tolerance emerged as the most predictive independent factor for graft failure, HR 1.66 (95% CI 1.22, 2.24), p = 0.001. These findings were consistent between the different transplant procedures performed. CONCLUSIONS/INTERPRETATION: We conclude that early post-transplant abnormal glucose tolerance is associated with later whole organ pancreas graft failure. An OGTT performed within the first month postoperatively provides an easily measurable assessment of an independent early risk factor of pancreatic graft dysfunction.

Seven newly identified loci for autoimmune thyroid disease.

Autoimmune thyroid disease (AITD), including Graves' disease (GD) and Hashimoto's thyroiditis (HT), is one of the most common of the immune-mediated diseases. To further investigate the genetic determinants of AITD, we conducted an association study using a custom-made single-nucleotide polymorphism (SNP) array, the ImmunoChip. The SNP array contains all known and genotype-able SNPs across 186 distinct susceptibility loci associated with one or more immune-mediated diseases. After stringent quality control, we analysed 103 875 common SNPs (minor allele frequency >0.05) in 2285 GD and 462 HT patients and 9364 controls. We found evidence for seven new AITD risk loci (P < 1.12 × 10(-6); a permutation test derived significance threshold), five at locations previously associated and two at locations awaiting confirmation, with other immune-mediated diseases.

Donor ABCB1 variant associates with increased risk for kidney allograft failure.

The impact of variation within genes responsible for the disposition and metabolism of calcineurin inhibitors (CNIs) on clinical outcomes in kidney transplantation is not well understood. Furthermore, the potential influence of donor, rather than recipient, genotypes on clinical endpoints is unknown. Here, we investigated the associations between donor and recipient gene variants with outcome among 4471 white, CNI-treated kidney transplant recipients. We tested for 52 single-nucleotide polymorphisms (SNPs) across five genes: CYP3A4, CYP3A5, ABCB1 (MDR1; encoding P-glycoprotein), NR1I2 (encoding the pregnane X receptor), and PPIA (encoding cyclophilin). In a discovery cohort of 811 patients from Birmingham, United Kingdom, kidney donor CC genotype at C3435T (rs1045642) within ABCB1, a variant known to alter protein expression, was associated with an increased risk for long-term graft failure compared with non-CC genotype (hazard ratio [HR], 1.69; 95% confidence interval [CI], 1.20-2.40; P=0.003). No other donor or recipient SNPs were associated with graft survival or mortality. We validated this association in 675 donors from Belfast, United Kingdom (HR, 1.68; 95% CI, 1.21-2.32; P=0.002), and in 2985 donors from the Collaborative Transplant Study (HR, 1.84; 95% CI, 1.08-3.13; P=0.006). In conclusion, these data suggest that an ABCB1 variant known to alter protein expression represents an attractive candidate for future study and risk stratification in kidney transplantation.

Parameters for reliable results in genetic association studies in common disease.

It is increasingly apparent that the identification of true genetic associations in common multifactorial disease will require studies comprising thousands rather than the hundreds of individuals employed to date. Using 2,873 families, we were unable to confirm a recently published association of the interleukin 12B gene in 422 type I diabetic families. These results emphasize the need for large datasets, small P values and independent replication if results are to be reliable.

Association of the thyroid stimulating hormone receptor gene (TSHR) with Graves' disease.

Graves' disease (GD) is a common autoimmune disease (AID) that shares many of its susceptibility loci with other AIDs. The thyroid stimulating hormone receptor (TSHR) represents the primary autoantigen in GD, in which autoantibodies bind to the receptor and mimic its ligand, thyroid stimulating hormone, causing the characteristic clinical phenotype. Although early studies investigating the TSHR and GD proved inconclusive, more recently we provided convincing evidence for association of the TSHR region with disease. In the current study, we investigated a combined panel of 98 SNPs, including 70 tag SNPs, across an extended 800 kb region of the TSHR to refine association in a cohort of 768 GD subjects and 768 matched controls. In total, 28 SNPs revealed association with GD (P < 0.05), with strongest SNP associations at rs179247 (chi(2) = 32.45, P = 8.90 x 10(-8), OR = 1.53, 95% CI = 1.32-1.78) and rs12101255 (chi(2) = 30.91, P = 1.95 x 10(-7), OR = 1.55, 95% CI = 1.33-1.81), both located in intron 1 of the TSHR. Association of the most associated SNP, rs179247, was replicated in 303 GD families (P = 7.8 x 10(-4)). In addition, we provide preliminary evidence that the disease-associated genotypes of rs179247 (AA) and rs12101255 (TT) show reduced mRNA expression ratios of flTSHR relative to two alternate TSHR mRNA splice variants.

Association of Fc receptor-like 5 (FCRL5) with Graves' disease is secondary to the effect of FCRL3.

OBJECTIVE: The Fc receptor-like 3 (FCRL3) molecule, involved in controlling B-cell signalling, may contribute to the autoimmune disease process. Recently, a genome-wide screen detected association of neighbouring gene FCRL5 with Graves' disease (GD). To determine whether FCRL5 represents a further independent B-cell signalling GD susceptibility loci, we screened 12 tag SNPs, capturing all known common variation within FCRL5, in 5192 UK Caucasian GD index cases and controls. DESIGN: A case-control association study investigating twelve tag SNPs within FCRL5 which captured the majority of known common variation within this gene region. PATIENTS: A data set comprising 2504 UK Caucasian patients with GD and 2688 geographically matched controls taken from the 1958 British Birth cohort. MEASUREMENTS: We used the chi-squared test and haplotype analysis to investigate the association between the tag SNPs and GD before performing logistic regression analysis to determine whether association at FCRL5 was independent of the known FCRL3 association. RESULTS: Three of the FCRL5 tag SNPs, rs6667109, rs3811035 and rs6692977 showed association with GD (P = 0·015-0·001, OR = 1·15-1·16). Logistic regression performed on all FCRL5 and, previously screened, FCRL3 tag SNPs revealed that association with FCRL5 was secondary to linkage disequilibrium with the FCRL3, rs11264798 and rs10489678 SNPs. CONCLUSIONS: FCRL5 does not appear to be exerting an independent effect on the development of GD in the UK. Fine mapping of the entire FCRL region is required to determine the exact location of the aetiological variant/s present.

Association of FcGRIIa with Graves' disease: a potential role for dysregulated autoantibody clearance in disease onset/progression.

OBJECTIVE: Although autoantibody production is a key feature of autoimmunity, it is not known whether variation in autoantibody production and clearance pathways is involved in disease susceptibility. The Fc Gamma Receptor IIa (FcGRIIa) molecule is involved in the clearance of autoantibodies and a functional single nucleotide polymorphism (SNP), rs1801274, which has been shown to alter autoantibody clearance, has been associated with a number of autoimmune diseases (AIDs) including systemic lupus erythematosus and type 1 diabetes. This study aimed to determine whether FcGRIIa is associated with Graves' disease (GD) in the UK Caucasian population by Tag SNP screening common polymorphisms within the FcGRIIa region. DESIGN: A case control association study investigating nine Tag SNPs within FcGRIIa, which captured the majority of known common variation within this gene region. PATIENTS: A dataset comprising 2504 UK Caucasian GD patients and 2784 geographically matched controls taken from the 1958 British Birth cohort. MEASUREMENTS: We used the chi(2)-test to investigate association between the Tag SNPs and GD. RESULTS: Association between the rs1801274 (P = 0.003, OR = 1.12 [95% CI = 1.03-1.22] and rs6427598 (P = 0.012, OR = 0.90 [95% CI = 0.83-0.98]) SNPs and GD was observed. No other SNPs showed association with GD. No associations were seen between any of the SNPs investigated and specific GD clinical phenotypes. CONCLUSIONS: This study suggests that variation in FcGRIIa predisposes to GD and further supports the role of FcGRIIa as a susceptibility locus for AIDs in general.

Association of caveolin-1 gene polymorphism with kidney transplant fibrosis and allograft failure.

CONTEXT: Caveolin-1 (CAV1) is an inhibitor of tissue fibrosis. OBJECTIVE: To study the association of CAV1 gene variation with kidney transplant outcome, using kidney transplantation as a model of accelerated fibrosis. DESIGN, SETTING, AND PATIENTS: Candidate gene association and validation study. Genomic DNA from 785 white kidney transplant donors and their respective recipients (transplantations in Birmingham, England, between 1996 and 2006; median follow-up, 81 months) were analyzed for common variation in CAV1 using a single-nucleotide polymorphism (SNP) tagging approach. Validation of positive findings was sought in an independent kidney transplant donor-recipient cohort (transplantations in Belfast, Northern Ireland, between 1986 and 2005; n = 697; median follow-up, 69 months). Association between genotype and allograft failure was initially assessed by Kaplan-Meier analysis, then in an adjusted Cox model. MAIN OUTCOME MEASURE: Death-censored allograft failure, defined as a return to dialysis or retransplantation. RESULTS: The presence of donor AA genotype for the CAV1 rs4730751 SNP was associated with increased risk of allograft failure in the Birmingham group (donor AA vs non-AA genotype in adjusted Cox model, hazard ratio [HR], 1.97; 95% confidence interval [CI], 1.29-3.16; P = .002). No other tag SNPs showed a significant association. This finding was validated in the Belfast cohort (in adjusted Cox model, HR, 1.56; 95% CI, 1.07-2.27; P = .02). Overall graft failure rates were as follows: for the Birmingham cohort, donor genotype AA, 22 of 57 (38.6%); genotype CC, 96 of 431 (22.3%); and genotype AC, 66 of 297 (22.2%); and for the Belfast cohort, donor genotype AA, 32 of 48 (67%); genotype CC, 150 of 358 (42%); and genotype AC, 119 of 273 (44%). CONCLUSION: Among kidney transplant donors, the CAV1 rs4730751 SNP was significantly associated with allograft failure in 2 independent cohorts.

CT60 and +49 polymorphisms of CTLA 4 are associated with ANCA-positive small vessel vasculitis.

OBJECTIVE: To investigate whether single nucleotide polymorphisms (SNPs) within cytotoxic T-lymphocyte antigen-4 (CTLA-4) are associated with ANCA-associated small vessel vasculitis (SVV). METHODS: The CTLA-4 CT60 (exon 4), +49 (exon 1) and -318 (promoter region) genotypes were determined by PCR and restriction fragment length polymorphism (RFLP) in 222 white Caucasians of UK origin with SVV and 670 ethnically matched controls. RESULTS: The CTLA-4 exon 1 (+49) and 4 (CT60) polymorphisms are associated with SVV (+49: chi(2) = 10.965, P = 0.004; CT60: chi(2) = 12.017, P = 0.002). Both disease-susceptible and disease-protective haplotypes have been identified in this cohort, and their frequencies are similar in the subtypes of WG and microscopic polyangiitis. CONCLUSION: This study provides further evidence that CTLA-4, a susceptibility locus for a number of common autoimmune diseases, may also be involved in the development of ANCA-associated SVV.

Exubera inhaled insulin in patients with type 1 and type 2 diabetes: the first 12 months.

BACKGROUND: Following National Institute for Clinical Excellence approval of inhaled insulin Exubera (Pfizer, New York, NY) in 2006, we established a dedicated clinic in January 2007 to monitor the efficacy and safety of Exubera. Between January and October 2007, eight patients started Exubera: six because of needle phobia (DSM-IV criteria) and two with injection site problems. METHODS: Data were collected at the clinic over a 12-month period from February 2007 at 3-, 6-, 9-, and 12-month intervals. The clinic is jointly led by a consultant diabetologist and a diabetes specialist nurse within the secondary care setting. RESULTS: Inhaled insulin was well tolerated in all eight patients who had previously experienced significant problems with initiation or intensification of subcutaneous insulin injections. Mean hemoglobin A1c was 10.7% (range, 8.1-14.2%) at initiation, 8.3% (7.2-9.4%) at 3 months, 7.7% (6.9-9.0%) at 6 months, 7.4% (6.7-8.4%) at 9 months, and 7.5% (6.5-8.7%) at 12 months. At 6 months, six patients had a reduction in forced expiratory volume in the first second (FEV1) by 4-12%, whereas five patients had a reduction of 2-12% at 12 months. One developed dyspnea, with a 29% fall in FEV1, which was transient and secondary to an upper respiratory tract infection. Two patients with the highest starting and most improved hemoglobin A1c developed significant retinopathy. CONCLUSIONS: Our 12-month audit data demonstrate that the initiation of inhaled insulin in this difficult-to-treat group of patients resulted in a significant improvement in glycemic control. The subsequent withdrawal of an alternative and acceptable form of insulin treatment now presents a renewed challenge for our patients and healthcare professionals.

Genetic developments in autoimmune thyroid disease: an evolutionary process.

The identification of genes placing individuals at an increased risk for the development of autoimmune thyroid disease (AITD) has been a slow process. However, over the last 20 years or so real progress has been made with the mapping of novel loci, via a number of different approaches. First, through the use of traditional immunological methods, Human Leucocyte Antigen (HLA)/Major Histocompatibility Complex (MHC) was the first gene region to be associated with AITD and consistent replications have been reported. Second, the CTLA-4 gene region on 2q33 was the first non-MHC replicated locus to be primarily identified using the candidate gene method. Third, family-based linkage studies led to the mapping of a new type 1 diabetes locus, the PTPN22 gene, which has subsequently been independently replicated as a susceptibility gene for Graves' disease (GD). Fourth, despite many unsuccessful attempts at implicating the TSHR gene as a susceptibility locus for GD, a recent approach of 'tagging' all the common variation within the gene has led to its identification as the first GD specific locus. Moreover, the use of tag single nucleotide polymorphisms (SNPs) has also been used to implicate the recently identified type 1 diabetes locus, CD25 as a susceptibility gene for GD. Finally, large scale, ongoing genome-wide association studies in multiple autoimmune diseases (AID) states, including AITD seem likely to lead to the identification of additional MHC and non-MHC susceptibility loci.

A review of human and analogue insulin trials.

A recent meta-analysis evaluated trials of the rapid-acting analogues insulin lispro and insulin aspart, performed before the introduction of the basal analogues, insulin glargine and insulin detemir. This article reviews the effect of rapid-acting and basal insulin analogues separately and in combination, relative to human insulin. Outcomes evaluated include HbA(1c), hypoglycaemia, postprandial glucose (PPG), and weight changes. Results from trials that matched defined criteria are presented in tables. In type 1 diabetes, compared with human insulin, the rapid-acting analogues generally reduced hypoglycaemia and postprandial glucose, whereas the basal analogues tended to reduce hypoglycaemia -- particularly nocturnal hypoglycaemia. Weight gain may also be reduced with basal analogues, compared with human basal insulin. In type 2 diabetes, premix rapid-acting analogues controlled postprandial glucose better than human insulin mixes; basal analogues used as basal-only therapy reduced hypoglycaemia compared with NPH insulin; and some advantages were apparent with analogues in basal-bolus therapy. Whilst the benefits on individual metabolic and clinical outcomes appear modest, almost all studies report some advantage when using insulin analogues in type 1 and type 2 diabetes. Significant benefits, including PPG lowering with the rapid-acting analogues and the potential for reduction in cardiovascular risk, should be investigated further.

Replication of an association between the lymphoid tyrosine phosphatase locus (LYP/PTPN22) with type 1 diabetes, and evidence for its role as a general autoimmunity locus.

In the genetic analysis of common, multifactorial diseases, such as type 1 diabetes, true positive irrefutable linkage and association results have been rare to date. Recently, it has been reported that a single nucleotide polymorphism (SNP), 1858C>T, in the gene PTPN22, encoding Arg620Trp in the lymphoid protein tyrosine phosphatase (LYP), which has been shown to be a negative regulator of T-cell activation, is associated with an increased risk of type 1 diabetes. Here, we have replicated these findings in 1,388 type 1 diabetic families and in a collection of 1,599 case and 1,718 control subjects, confirming the association of the PTPN22 locus with type 1 diabetes (family-based relative risk (RR) 1.67 [95% CI 1.46-1.91], and case-control odds ratio (OR) 1.78 [95% CI 1.54-2.06]; overall P = 6.02 x 10(-27)). We also report evidence for an association of Trp(620) with another autoimmune disorder, Graves' disease, in 1,734 case and control subjects (P = 6.24 x 10(-4); OR 1.43 [95% CI 1.17-1.76]). Taken together, these results indicate a more general association of the PTPN22 locus with autoimmune disease.