title: Elevated Levels of Plasma IgA Autoantibodies against Oxidized LDL Found in Proliferative Diabetic Retinopathy but Not in Nonproliferative Retinopathy.
abstract: Aims. This study investigated the association of autoantibodies binding to oxidized low-density lipoproteins (oxLDL) in diabetic retinopathy (DR).Methods. Plasma from 229 types 1 and 2 patients with DR including diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) was analysed with ELISA-based assay to determine IgA, IgG, and IgM autoantibody levels binding to oxLDL. The controls were 106 diabetic patients without retinopathy (NoDR) and 139 nondiabetic controls (C).Results. PDR group had significantly higher IgA autoantibody levels than DME or NoDR: mean 94.9 (SD 54.7) for PDR, 75.5 (41.8) for DME (p= 0.001), and 76.1 (48.2) for NoDR (p= 0.008). There were no differences in IgG, IgM, or IgA that would be specific for DR or for DME. Type 2 diabetic patients had higher levels of IgA autoantibodies than type 1 diabetic patients (86.0 and 65.5, resp.,p= 0.004) and the highest levels in IgA were found in type 2 diabetic patients with PDR (119.1,p> 0.001).Conclusions. IgA autoantibodies were increased in PDR, especially in type 2 diabetes. The high levels of IgA in PDR, and especially in type 2 PDR patients, reflect the inflammatory process and enlighten the role of oxLDL and its autoantibodies in PDR.
authors.affiliation: PEDEGO Research Unit, Department of Ophthalmology, Medical Research Center (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland; Research Unit of Internal Medicine, Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland.
authors.forename: Satu
authors.identifier: 0000-0002-3836-6839
authors.initials: S
authors.lastname: Vavuli
authors.affiliation: Research Unit of Internal Medicine, Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland.
authors.forename: Tuire
authors.identifier: 0000-0001-5104-5792
authors.initials: T
authors.lastname: Salonurmi
authors.affiliation: Department of Ophthalmology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
authors.forename: Sirpa
authors.identifier: 0000-0002-2506-3900
authors.initials: S
authors.lastname: Loukovaara
authors.affiliation: Research Unit of Internal Medicine, Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland; Research Unit of Biomedicine, Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: Antti E
authors.identifier: 0000-0003-4771-2753
authors.initials: AE
authors.lastname: Nissinen
authors.affiliation: Research Unit of Internal Medicine, Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland; Biocenter Oulu, University of Oulu, Oulu, Finland.
authors.forename: Markku J
authors.initials: MJ
authors.lastname: Savolainen
authors.affiliation: PEDEGO Research Unit, Department of Ophthalmology, Medical Research Center (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland; Research Unit of Internal Medicine, Medical Research Center Oulu (MRC Oulu), Oulu University Hospital and University of Oulu, Oulu, Finland.
authors.forename: M Johanna
authors.identifier: 0000-0003-3424-7207
authors.initials: MJ
authors.lastname: Liinamaa
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000276:immunology; D003930:Diabetic Retinopathy / Q000097:blood / Q000276:immunology*; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D008077:Lipoproteins, LDL / Q000276:immunology*; D008297:Male; D008875:Middle Aged
chemical_list: D001323:Autoantibodies; D007070:Immunoglobulin A; D008077:Lipoproteins, LDL; C099252:oxidized low density lipoprotein