Immunoglobulin A antibodies to oxidized collagen type II as a potential biomarker for the stratification of spondyloarthritis from rheumatoid arthritis.

OBJECTIVES: The discovery of diseased tissue-specific neoantigens offers the opportunity to develop important disease tissue-specific biomarkers that can help in the prediction, diagnosis, and stratification of diseases. This opportunity is specifically significant for autoimmune diseases where diagnostic biomarkers are not available. Inflammatory autoimmune diseases are commonly associated with local generation of large amounts of reactive oxidants. We have previously identified oxidative post-translationally modified (oxPTM) tissue-specific neoantigens in rheumatoid arthritis (RA) and type 1 diabetes that elicit an immune response. In the current study, we studied the presence and clinical significance of antibodies to oxPTM collagen type II (CII) in patients with spondyloarthritis (SpA). METHOD: Levels of antibodies specific to native CII and oxPTM-CII were assessed by enzyme-linked immunosorbent assay. RESULTS: Immunoglobulin G (IgG) binding to oxPTM-CII was observed in 52%, 83%, and 28% of serum samples from patients with axial spondyloarthritis (axSpA), RA, and psoriatic arthritis (PsA), respectively. Importantly, while strong IgA anti-oxPTM-CII responses were detected in axSpA and PsA patients, with 47% and 84% respective binders, no IgA anti-oxPTM-CII was detected in RA patients. IgA anti-oxPTM-CII reactivity in axSpA patients treated with biologics was higher and more frequent, with 85% binders compared to 9% binders in patients treated with synthetic disease-modifying anti-rheumatic drugs. CONCLUSION: Our data imply that SpA and PsA are associated with the presence of antibodies to oxPTM-CII, suggesting that there may be a humoral component that may distinguish patients with SpA from RA. Our approach could be adapted to other diseases, particularly to inflammatory autoimmune diseases.

HLA-dependent autoantibodies against post-translationally modified collagen type II in type 1 diabetes mellitus.

AIMS/HYPOTHESIS: In this study the involvement of oxidative stress in type 1 diabetes mellitus autoimmunity and the possible association with rheumatoid arthritis (RA) was investigated. We tested the hypothesis that oxidative stress induced by chronic hyperglycaemia triggers post-translational modifications and thus the formation of neo-antigens in type 1 diabetes, similar to the ones found in RA. METHODS: Collagen type II (CII), a known autoantigen in RA, was treated with ribose and various reactive oxygen species (ROS). Levels of antibodies specific to native and ROS-modified CII (ROS-CII) were compared in type 1 diabetes, type 2 diabetes and healthy controls, and related to the HLA genotype. RESULTS: Significantly higher binding to ROS-CII vs native CII was observed in type 1 diabetic patients possessing the HLA-DRB1*04 allele irrespective of variables of glucose control (blood glucose or HbA(1c)). Type 1 diabetic patients carrying a DRB1*04 allele with the shared epitope showed the highest risk for ROS-CII autoimmunity, while the DRB1*0301 allele was protective. Conversely, native CII autoimmunity was not associated with any specific DRB1 allele. Positive and inverse seroconversion rates of response to ROS-CII were high in DRB1*04-positive type 1 diabetic patients. CONCLUSION: Hyperglycaemia and oxidative stress may trigger genetically controlled autoimmunity to ROS-CII and may explain the association between type 1 diabetes mellitus and RA.

Pre-culturing human adipose tissue mesenchymal stem cells under hypoxia increases their adipogenic and osteogenic differentiation potentials.

OBJECTIVES: Hypoxia is an important factor in many aspects of stem-cell biology including their viability, proliferation, differentiation and migration. We evaluated whether low oxygen level (2%) affected human adipose tissue mesenchymal stem-cell (hAT-MSC) phenotype, population growth, viability, apoptosis, necrosis and their adipogenic and osteogenic differentiation potential. MATERIALS AND METHODS: hAT-MSCs from four human donors were cultured in growth medium under either normoxic or hypoxic conditions for 7 days and were then transferred to normoxic conditions to study their differentiation potential. RESULTS: Hypoxia enhanced hAT-MSC expansion and viability, whereas expression of mesenchymal markers such as CD90, CD73 and endothelial progenitor cell marker CD34, remained unchanged. We also found that pre-culturing hAT-MSCs under hypoxia resulted in their enhanced ability to differentiate into adipocytes and osteocytes. CONCLUSIONS: This protocol could be useful for maximizing hAT-MSC potential to differentiate in vitro into the adipogenic and osteogenic lineages, for use in plastic and reconstructive surgery, and in tissue engineering strategies.

Blood glucose monitoring in the normal population: the PREDICA study.

In the PREdiction of DIabetes from CApillary blood glucose (PREDICA) study, we propose a novel approach based on multiple capillary blood glucose (CBG) measurements, assuming that weekly measurements performed for 2 months may be an efficient strategy to screen for diabetes. We studied 538 Caucasian subjects (247 men and 291 women) without a history of diabetes, consecutively recruited by 50 GPs from the Italian provinces of Rome and Frosinone. Subjects were asked to perform 8 fasting glucose and 8 post-prandial glucose measurements during a frame time of 2 months (Glucometer Accu-chek AVIVA Roche Diagnostics). Study subjects were 55 ± 9 years old (range 22-77 years of age), 50% were overweight and 16% obese. Fifty-eight percent of subjects have performed 13 to 16 CBG measurements during the study, 68% of subjects have performed at least 5 out of 8, both fasting and post-prandial measurements. Among 492 subjects who had at least two fasting measurements, 63.6% had normal glucose levels, 25.4% showed IFG, and 11.0% were diabetic. Considering post-prandial measurements, 74.2% had normal glucose levels, 23.0% had IGT, and 2.8% were diabetic. Combined IFG + IGT was detected in 7% of study subjects, while in 0.8% diagnosis of diabetes was confirmed with both fasting and post-prandial measurements. In this study, we found a high adherence to a novel screening strategy based on self-glucose monitoring in the general population. Our results show that multiple CBG measurements may represent a simple and efficient method for diabetes screening.

Buccal spray insulin in subjects with impaired glucose tolerance: the prevoral study.

AIM: Postprandial hyperglycaemia is a consequence of reduced first phase insulin response and is associated with increased cardiovascular risk and mortality. The aim of this proof-of-concept study was to investigate the safety and efficacy of treatment with buccal spray insulin (Oral-lyn™, Generex Biotechnology Corporation, Toronto, Ontario, Canada) on postprandial plasma glucose and insulin levels in subjects with impaired glucose tolerance (IGT). METHODS: A total of 19 female and 12 male Caucasian subjects, 52.2 ± 13.5 (SD) years old, having a body mass index of 33.1 ± 6 (SD) kg/m² with confirmed IGT were included in the study. Subjects were randomized to take 4, 6 or 12 Oral-lyn puffs (1 puff = 1 s.c. rapid insulin UI) split into two equal doses each, one before and the second 30 min after a standard 75 g oral glucose tolerance test (OGTT). Glucose and insulin levels were measured at baseline and 30, 60, 90, 120 and 180 min afterwards. RESULTS: Glucose fluctuations during OGTT were not modified by 4 or 6 Oral-lyn puffs. Treatment with 12 puffs was followed by 29.6% decrease in plasma glucose at 2 h and 26.8% decrease at 3 h, altogether p = 0.01. Considering all time points of the OGTT, there was a mean reduction of 15.8% in glucose levels. With 6 of the total 12 puffs used in group C there was a significant increase in the insulin levels during OGTT at 30 min (p < 0.04) but not at 2 or 3 h. No hypoglycaemic episodes were observed at any time points of the OGTT. CONCLUSIONS: This proof-of-concept study demonstrates that treatment with buccal spray insulin is a simple and valuable therapy for reducing postprandial hyperglycaemia in obese subjects with IGT. Importantly, this treatment is safe and none of the study subjects experienced hypoglycaemia.