Does β-Cell Autoimmunity Play a Role in Cystic Fibrosis-Related Diabetes? Analysis Based on the German/Austrian Diabetes Patienten Verlaufsdokumentation Registry

The Prognosis of Glutamic Acid Decarboxylase Antibodies in Women With Hyperglycemia in Pregnancy

CONTEXT

We recently reported that the presence of glutamic acid decarboxylase antibodies (GADA) was not associated with large-for-gestational-age infants in women with hyperglycemia in pregnancy (HIP).

OBJECTIVE

We explored the association between the presence of GADA and other HIP-related adverse pregnancy outcomes.

METHODS

This observational prospective study, conducted at a university hospital in a suburb of Paris, France, included 1182 consecutive women with HIP measured for GADA at HIP care initiation between 2012 and 2017. Post hoc analyses for outcomes included gestational weight gain, insulin therapy, cesarean delivery, hypertensive disorders, small-for-gestational-age infant, prematurity, and neonatal hypoglycemia.

RESULTS

Of the 1182 women studied, 87 (7.4%) had positive (≥ 1 IU/mL) GADA. Although socioeconomic, clinical, and biological characteristics were similar across women in the positive and negative GADA groups, higher fasting plasma glucose values during early HIP screening were observed in the former (5.5 ± 1.5 vs 5.2 ± 0.7 mmol/L respectively, P < .001). At HIP care initiation, fructosamine levels were higher in women with positive GADA (208 ± 23 vs 200 ± 18 µmol/L; P < .05). In the homeostatic model assessment, insulin resistance (HOMA-IR) and beta secretion (HOMA-B) rates were similar in both groups. Gestational weight gain and the rates of all adverse outcomes were similar in both groups except for cesarean delivery (18.4 and 27.3% for positive and negative GADA, respectively; adjusted odds ratio 0.49 [95% CI, 0.26-0.92], P = .026).

CONCLUSION

Universal measurement of GADA in women with HIP highlighted that 7.4% had positive GADA. No association was observed between GADA and HIP-related adverse pregnancy outcomes, except a lower risk of cesarean delivery.

Autoimmunity in people with cystic fibrosis

Cystic fibrosis (CF) clinicians may see patients who have difficult-to-manage symptoms that do not have a clear CF-related etiology, such as unusual gastrointestinal (GI) complaints, vasculitis, or arthritis. Alterations in immunity, inflammation and intraluminal dysbiosis create a milieu that may lead to autoimmunity, and the CF transmembrane regulator protein may have a direct role as well. While autoantibodies and other autoimmune markers may develop, these may or may not lead to organ involvement, therefore they are helpful but not sufficient to establish an autoimmune diagnosis. Autoimmune involvement of the GI tract is the best-established association. Next steps to understand autoimmunity in CF should include a more in-depth assessment of the community perspective on its impact. In addition, bringing together specialists in various fields including, but not limited to, pulmonology, gastroenterology, immunology, and rheumatology, would lead to cross-dissemination and help define the path forward in basic science and clinical practice.

Cystic fibrosis autoantibody signatures associate with Staphylococcus aureus lung infection or cystic fibrosis-related diabetes

Introduction

While cystic fibrosis (CF) lung disease is characterized by persistent inflammation and infections and chronic inflammatory diseases are often accompanied by autoimmunity, autoimmune reactivity in CF has not been studied in depth.

Methods

In this work we undertook an unbiased approach to explore the systemic autoantibody repertoire in CF using autoantibody microarrays.

Results and discussion

Our results show higher levels of several new autoantibodies in the blood of people with CF (PwCF) compared to control subjects. Some of these are IgA autoantibodies targeting neutrophil components or autoantigens linked to neutrophil-mediated tissue damage in CF. We also found that people with CF with higher systemic IgM autoantibody levels have lower prevalence of S. aureus infection. On the other hand, IgM autoantibody levels in S. aureus-infected PwCF correlate with lung disease severity. Diabetic PwCF have significantly higher levels of IgA autoantibodies in their circulation compared to nondiabetic PwCF and several of their IgM autoantibodies associate with worse lung disease. In contrast, in nondiabetic PwCF blood levels of IgA autoantibodies correlate with lung disease. We have also identified other autoantibodies in CF that associate with P. aeruginosa airway infection. In summary, we have identified several new autoantibodies and associations of autoantibody signatures with specific clinical features in CF.

Screening strategies for glucose tolerance abnormalities and diabetes in people with cystic fibrosis

The increase in life expectancy of patients with cystic fibrosis has come with new comorbidities, particularly diabetes. The gradual development of glucose tolerance abnormalities means that 30 to 40% of adults will be diabetic. Cystic fibrosis-related diabetes is a major challenge in the care of these patients because it is a morbidity and mortality factor at all stages of the disease. Early glucose tolerance abnormalities observed from childhood, before the stage of diabetes, are also associated with a poor pulmonary and nutritional outcome. The long asymptomatic period justifies systematic screening with an annual oral glucose tolerance test from the age of 10 years. However, this strategy does not take into account the new clinical profiles of patients with cystic fibrosis, recent pathophysiological knowledge of glucose tolerance abnormalities, and the emergence of new diagnostic tools in diabetology. In this paper, we summarise the challenges of screening in the current context of new patient profiles - patients who are pregnant, have transplants, or are being treated with fibrosis conductance transmembrane regulator modulators - and put forward an inventory of the various screening methods for cystic fibrosis-related diabetes, including their applications, limitations and practical implications.

Autoimmunity May Explain Diabetes in a Subset of Patients With Recurrent Acute and Chronic Pancreatitis: A Pilot Study

Pancreatogenic diabetes mellitus, also termed type 3c diabetes (T3cD), or glucose intolerance develops in 25%-75% of adults with chronic pancreatitis (CP). The primary pathophysiologic defect in T3cD is insulin deficiency, thought to result largely from "bystander" injury to the islets from fibrotic changes in the exocrine pancreas and cytokine-induced beta cell dysfunction from intrapancreatic inflammation.¹.

Cystic Fibrosis-Related Diabetes: Clinical approach and knowledge gaps

Cystic Fibrosis-Related Diabetes (CFRD) is a unique type of diabetes mellitus that shares some features with both type 1 and type 2 diabetes. Yet, its distinguishing feature of acute pulmonary complications associated with hyperglycemia and the catabolic metabolism associated with a relative insulin deficiency poses challenges to the application of traditional definitions and treatments for diabetes mellitus. People with CF (pwCF) undergo rigorous annual screening starting at age 10, a process that is challenging for patients and limited by sensitivity, specificity, and reproducibility. As pwCF continue to live longer, over 50% are expected to develop CFRD over their lifetime, including up to 20% of adolescents. Increasing numbers of people with CFRD will make this disease increasingly relevant to diabetes practitioners. Evidence-guided practice in CFRD care is limited by small and short studies. Our current understanding of CFRD may change significantly with the recent introduction of CF Transmembrane Regulator (CFTR) modulator medications. This review will explore current challenges in the diagnosis and management of CFRD, specifically highlighting knowledge gaps in the pathophysiology of CFRD, optimal screening methods, priorities for research and provide guidance with regards to screening, diagnosis, and treatment.

The Potential Causes of Cystic Fibrosis-Related Diabetes

Cystic fibrosis (CF) is a genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR). Cystic fibrosis-related diabetes (CFRD) is the most common comorbidity, affecting more than 50% of adult CF patients. Despite this high prevalence, the etiology of CFRD remains incompletely understood. Studies in young CF children show pancreatic islet disorganization, abnormal glucose tolerance, and delayed first-phase insulin secretion suggesting that islet dysfunction is an early feature of CF. Since insulin-producing pancreatic β-cells express very low levels of CFTR, CFRD likely results from β-cell extrinsic factors. In the vicinity of β-cells, CFTR is expressed in both the exocrine pancreas and the immune system. In the exocrine pancreas, CFTR mutations lead to the obstruction of the pancreatic ductal canal, inflammation, and immune cell infiltration, ultimately causing the destruction of the exocrine pancreas and remodeling of islets. Both inflammation and ductal cells have a direct effect on insulin secretion and could participate in CFRD development. CFTR mutations are also associated with inflammatory responses and excessive cytokine production by various immune cells, which infiltrate the pancreas and exert a negative impact on insulin secretion, causing dysregulation of glucose homeostasis in CF adults. In addition, the function of macrophages in shaping pancreatic islet development may be impaired by CFTR mutations, further contributing to the pancreatic islet structural defects as well as impaired first-phase insulin secretion observed in very young children. This review discusses the different factors that may contribute to CFRD.

Acute hyperosmolar hyperglycaemic state in cystic fibrosis-related diabetes caused by glucocorticoid and itraconazole interaction

Hyperosmolar hyperglycaemic state (HHS) has not previously been reported in cystic fibrosis-related diabetes (CFRD). We report the case of a 15-year old boy with stable CFRD who developed acute HHS after treatment with glucocorticoids and itraconazole for presumed allergic broncho-pulmonary aspergillosis (ABPA). This case highlights the dangerous and preventable combination of high glucose intake, glucocorticoids and itraconazole inhibition of CYP3A4 (with resultant glucocorticoid accumulation) that can result in a state of life- threatening HHS in an adolescent with previously stable CFRD.

Pre-existing self-reactive IgA antibodies associated with primary graft dysfunction after lung transplantation

BACKGROUND

Primary graft Dysfunction (PGD) results in significant mortality and morbidity after lung transplantation (LT). The objective of this study was to evaluate if pre-existing antibodies to self-antigens in sera of LT recipients are associated with PGD.

METHODS

The serum profiles of IgG and IgA autoantibodies were analyzed using a customized proteomic microarray bearing 124 autoantigens. Autoantibodies were analyzed using Mann-Whitney U test or Fisher exact test. The association of the autoantibodies with clinical phenotypes and survival was analyzed by Kaplan-Meier Survival Analysis. Receiver operating curve characteristics (ROC) were calculated to evaluate the predictive value of the autoantibodies for PGD.

RESULTS

51 patients were included in this study. Autoantigen microarray analysis on the pre-transplantation samples identified 17 IgA and 3 IgG autoantibodies which were significantly higher in recipients who developed PGD compared to those who did not (adjusted p < .05 and fold change>1.5). 6 IgA Abs were significantly associated with survival. Taken as a panel, an elevation of 6 IgA Abs had significant predictive value for PGD. Area under the curve value for the panel was 0.9413 for PGD with ROC analysis. Notably, 6 of the 17 IgA autoantigen targets are belong to proteoglycan family of extracellular matrix proteins.

CONCLUSION

Pre-existing IgG and IgA autoantibodies in LT patients correlate with PGD and with survival in a single center, small cohort of lung transplant recipients. Further validation is needed to confirm the findings in the study.

Diabetes Mellitus in Children with Acute Recurrent and Chronic Pancreatitis: Data From the INternational Study Group of Pediatric Pancreatitis: In Search for a CuRE Cohort

OBJECTIVES

Adults with chronic pancreatitis (CP) have a high risk for developing pancreatogenic diabetes mellitus (DM), but little is known regarding potential risk factors for DM in children with acute recurrent pancreatitis (ARP) or CP. We compared demographic and clinical features of children with ARP or CP, with and without DM, in the INternational Study Group of Pediatric Pancreatitis: In Search for a CuRE (INSPPIRE) registry.

METHODS

We reviewed the INSPPIRE database for the presence or absence of physician-diagnosed DM in 397 children, excluding those with total pancreatectomy with islet autotransplantation, enrolled from August 2012 to August 2017. Patient demographics, BMI percentile, age at disease onset, disease risk factors, disease burden, and treatments were compared between children with DM (n = 24) and without DM (n = 373).

RESULTS

Twenty-four children (6% of the cohort) had a diagnosis of DM. Five of 13 tested were positive for beta cell autoantibodies. The DM group was 4.2 years [95% confidence interval (CI) 3-5.4] older at first episode of acute pancreatitis, and tended to more often have hypertriglyceridemia [odds ratio (OR) 5.21 (1.33-17.05)], coexisting autoimmune disease [OR 3.94 (0.88-13.65)] or pancreatic atrophy [OR 3.64 (1.13, 11.59)].

CONCLUSION

Pancreatic atrophy may be more common among children with DM, suggesting more advanced exocrine disease. However, data in this exploratory cohort also suggest increased autoimmunity and hypertriglyceridemia in children with DM, suggesting that risk factors for type 1 and type 2 DM, respectively may play a role in mediating DM development in children with pancreatitis.

Characteristics of cystic fibrosis-related diabetes: Data from two different sources the European cystic fibrosis society patient registry and German/Austrian diabetes prospective follow-up registry

BACKGROUND

Standardized patient registries provide a unique basis to get insight into cystic fibrosis (CF)-related diabetes (CFRD), the most common comorbidity in CF.

METHODS

A total of 3853 CFRD patients from the European CF Society Patient Registry (ECFSPR) and 752 from the German/Austrian diabetes prospective follow-up (diabetes patienten verlaufsdokumentation [DPV]) were studied. To adjust for age and sex, multivariable regression was used (SAS 9.4).

RESULTS

DPV subjects were younger (26.5 [20.2-32.6] vs 28.3 [21.7-36.0] years, P < 0.001) and more often female (59.6 vs 50.9%, P < 0.001). In both registries, F508del homozygotes were most frequent, with higher proportion in DPV (80.9 vs 57.8%, P = 0.003). After adjustment, lung-transplantation (LTX) was more common in ECFSPR (18.9 vs 4.9%, P < 0.001), although duration since LTX (4.8 ± 0.2 vs 5.5 ± 0.7 years, P = 0.33) did not differ. In DPV patients without LTX, a lower BMI (19.6 ± 0.1 vs 21.0 ± 0.1 kg/m² , P < 0.001), higher proportion of underweight (41.2 vs 20.2%, P < 0.001) and a tendency towards worse lung function (%FEV₁ : 42.3 ± 4.2 vs 48.3 ± 0.5%, P = 0.16) were observed.

CONCLUSIONS

Between both registries, demographic and clinical differences of CFRD were present. Besides different kind of data sources, diverse treatment structures between countries may play a role. The results may further indicate a more serious illness in patients treated in specialized diabetes clinics, documenting their data in DPV.

MARKEDLY DELAYED INSULIN SECRETION AND A HIGH RATE OF UNDETECTED OVERT DIABETES CHARACTERIZE GLUCOSE METABOLISM IN ADULT PATIENTS WITH CYSTIC FIBROSIS AFTER LUNG TRANSPLANTATION

OBJECTIVE

Cystic fibrosis-related diabetes (CFRD) is associated with adverse clinical outcomes and should be screened for by an annual oral glucose tolerance test (OGTT). Since pathophysiologic studies have mainly been performed in a pediatric/adolescent, nontransplanted collective, we aimed to assess parameters of insulin secretion and sensitivity in adult cystic fibrosis (CF) patients after lung transplantation (LT).

METHODS

Twelve adult CF patients after LT without known diabetes (33.3 ± 11.5 years; body mass index [BMI] 21.5 ± 3.3 kg/m²) and 8 control subjects matched by age (36.0 ± 6.6 years; P>.05), BMI (22.3 ± 1.5 kg/m²; P>.05), and gender (CON group) underwent a 3-hour OGTT with glucose, insulin, and C-peptide measurements. Parameters of insulin secretion and sensitivity as well as lipid profiles were assessed.

RESULTS

In the CF group, 4 patients were diagnosed with overt diabetes (CFRD) compared to CF patients without diabetes (CF-noDM), of whom 6 had indeterminate glycemia with 1-h glucose values >200 mg/dL. The insulin peak after glucose load occurred after 30 minutes in CON, after 90 minutes in CF-noDM, and was missing in CFRD. Insulin sensitivity was comparable between the groups. Beta-cell glucose sensitivity was markedly reduced in CFRD (10.7 ± 5.8 pmol/min*m²*mM), higher in CF-noDM (39.9 ± 23.4 pmol/min*m²*mM), but still significantly lower compared to CON (108.3 ± 53.9 pmol/min*m²*mM; P = .0008). CFRD patients exhibited increased triglyceride levels and decreased high-density lipoprotein levels.

CONCLUSION

Adult CF patients after LT have profound disturbances in glucose metabolism, with a high rate of undetected diabetes and markedly delayed insulin secretion. Curbed beta-cell glucose sensitivity rather than insulin resistance explains postprandial hyperglycemia and is accompanied by abnormalities in lipid metabolism.

ABBREVIATIONS

AUC = area under the curve; BMI = body mass index; CF = cystic fibrosis; CFRD = cystic fibrosis-related diabetes; CFTR = cystic fibrosis transmembrane-conductance regulator; CF-TX = cystic fibrosis patients who underwent lung transplantation; CGM = continuous glucose monitoring; HbA1c = glycated hemoglobin; HDL = high-density lipoprotein; INDET = indeterminate glycemia; LDL = low-density lipoprotein; LT = lung transplantation; OGIS = oral glucose sensitivity index; OGTT = oral glucose tolerance test; QUICKI = quantitative insulin sensitivity check index.

Islet Interleukin-1β Immunoreactivity Is an Early Feature of Cystic Fibrosis That May Contribute to β-Cell Failure

OBJECTIVE

Cystic fibrosis-related diabetes (CFRD) is a common complication of cystic fibrosis (CF), increasing patient morbidity and mortality. Poor understanding of CFRD pathogenesis limits the development of targeted therapies to treat and/or prevent the disease. The aim of this study was to evaluate islet pathology, specifically, inflammation, amyloid deposition, and endocrine cell composition in subjects with CF with diabetes and with CF without diabetes.

RESEARCH DESIGN AND METHODS

A retrospective analysis of archived pancreas tissue collected at autopsy was conducted using pancreas tissue from subjects with CF and diabetes (CFRD) (n = 18) and CF without diabetes (CF-no DM) (n = 17). Two cohorts of control non-CF subjects were identified, each matched to CFRD and CF-no DM subjects for age, sex, and BMI (non-CF older, n = 20, and non-CF younger, n = 20), respectively. Immunohistochemistry was performed to assess interleukin-1β (IL-1β) and islet hormone (insulin, glucagon, somatostatin, and pancreatic polypeptide) immunoreactivity; histochemistry was performed to quantify amyloid deposition.

RESULTS

Islet IL-1β immunoreactivity was substantially increased in both CFRD and CF-no DM subjects compared with non-CF subjects and was common in young subjects with CF (≤10 years of age). In contrast, islet amyloid deposition was increased only in CFRD subjects. We also observe abnormal islet hormone immunoreactivity, characterized by increased glucagon immunoreactivity, in CF-no DM and CFRD subjects compared with non-CF subjects.

CONCLUSIONS

These findings reveal novel molecular pathways and therapeutic targets underlying islet pathology in CF subjects and may be important in developing new approaches to treat CFRD.

Understanding childhood diabetes mellitus: new pathophysiological aspects

Diabetes mellitus (DM) is not a single disease, but several pathophysiological conditions where synthesis, release, and/or action of insulin are disturbed. A progressive autoimmune/autoinflammatory destruction of islet cells is still considered the main pathophysiological event in the development of T1DM, but there is evidence that T1DM itself is a heterogeneous disease. More than 50 gene regions are closely associated with T1DM and a variety of epigenetic factors and metabolic patterns have been characterized, which may play a role in the development of T1DM. The pathogenesis and genetics of type 2 DM (T2DM) are distinct from T1DM. Genes associated with T2DM are distinct from those in T1DM. Characteristic metabolic patterns, different from those in T1DM were reported in T2DM, and some children with T2DM also express islet-antibodies. Huge progress has been made in the characterization of other specific types of DM, which had been considered very rare before. The molecular clarification of maturity-onset diabetes of the young (MODY) has greatly improved our understanding of the pathophysiology of DM. There are genetic overlaps between T2DM and monogenetic DM. Neonatal DM has been shown to be monogenetic in most cases, and genetic elucidation leads to more precise and individualized therapies. Cystic fibrosis related DM (CFRDM) should be considered a genuine part of cystic fibrosis, and not a complication, since pancreatic fibrosis does not sufficiently explain the pathophysiology of CFRDM. Disturbances of cystic fibrosis transmembrane conductance regulator (CFTR) as well as autoimmunity are involved in the pathogenesis of CFRDM.

Patient and Disease Characteristics Associated With the Presence of Diabetes Mellitus in Adults With Chronic Pancreatitis in the United States

OBJECTIVES

Diabetes mellitus (DM) is a common complication of chronic pancreatitis (CP). Past studies for DM risk factors in CP have been limited to single centers or highly focused on a single etiology such as alcoholic or hereditary disease. We studied risk factors for DM in a large population of patients with CP of all etiologies enrolled in the North American Pancreatitis 2 studies.

METHODS

Participants (1,171) with CP (n=383 with DM, n=788 without DM) were enrolled prospectively from 26 participating centers. Questionnaires were completed by patients and physicians in a cross-sectional assessment. Patient demographics and disease characteristics were compared for CP with DM vs. without DM. Logistic regression was performed to assess the variables associated with DM diagnosis in a multivariable model.

RESULTS

Diabetics were more likely to be black (P=0.02), overweight, or obese (P<0.001), and with a family history of DM (P=0.0005). CP patients with DM were more likely to have pancreatic calcifications (63% vs. 54%, P=0.002), atrophy (44% vs. 32%, P<0.0001), and prior pancreas surgery (26.9% vs. 16.9%, P<0.0001). In multivariate logistic regression modeling, the strongest risk factors for DM were obesity (odds ratio (OR) 2.8, 95% confidence interval (CI) 1.9, 4.2) and exocrine insufficiency (OR 2.4, 95% CI 1.8, 3.2).

CONCLUSIONS

In this large multicenter cohort of patients with CP, exocrine insufficiency, calcifications, and pancreas surgery conveyed higher odds of having DM. However, the traditional 'type 2 DM' risk factors of obesity and family history were similarly important in conveying risk for DM.