title: TNF-alpha levels in tears: a novel biomarker to assess the degree of diabetic retinopathy.
abstract: We assess the level of tumour necrosis factor alpha (TNF-alpha) in tear fluids and other serum parameters associated with diabetes in different degrees of diabetic retinopathy. We have performed a prospective, nonrandomized, observational study. Study population consisted of 16 healthy subjects (controls) and 32 type 2 diabetic patients: 16 affected by proliferative diabetic retinopathy (PDR) and 16 with nonproliferative retinopathy (NDPR, background/preproliferative). Body mass index, urinary albumin, blood glucose, HbA1c, and tear levels of TNF-alpha were measured in all subjects. The value of glycaemia, microalbuminurea, and Body mass index in diabetic retinopathy groups were higher than those in control group (P < 0.05). Glycemia in NPDR: 6.6 mmol/L (range: 5.8-6.3); in PDR: 6.7 mmol/L (range: 6.1-7.2); in control: 5.7 mmol/L (range: 4.9-6.1); microalbuminurea in NPDR: 10.6 mg/L (range: 5.6-20); in PDR: 25.2 mg/L (range: 17-40); in control: 5.3 mg/L (range: 2.6-10); Body mass index in NPDR: 26 Kg/m(2) (range: 20.3-40); in PDR: 28 Kg/m(2) (range 20.3-52); in control: 21 Kg/m(2) (range 19-26). The TNF-alpha concentrations in tears increase with the severity of pathology and were lower in control group than in diabetic subjects. In the end, the level of TNF-alpha is highly correlated with severity of diabetic retinopathy and with nephropathy. Tear fluid collection may be a useful noninvasive method for the detection of proliferative diabetic retinopathy.
authors.affiliation: Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Costagliola
authors.forename: V
authors.initials: V
authors.lastname: Romano
authors.forename: M
authors.initials: M
authors.lastname: De Tollis
authors.forename: F
authors.initials: F
authors.lastname: Aceto
authors.forename: R
authors.initials: R
authors.lastname: dell'Omo
authors.forename: M R
authors.initials: MR
authors.lastname: Romano
authors.forename: C
authors.initials: C
authors.lastname: Pedicino
authors.forename: F
authors.initials: F
authors.lastname: Semeraro
mesh_terms: D000368:Aged; D000418:Albumins / Q000737:chemistry; D015415:Biomarkers / Q000737:chemistry*; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000175:diagnosis*; D003930:Diabetic Retinopathy / Q000175:diagnosis*; D005260:Female; D006442:Glycated Hemoglobin / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013666:Tears / Q000737:chemistry*; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry*
chemical_list: D000418:Albumins; D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D014409:Tumor Necrosis Factor-alpha; C517652:hemoglobin A1c protein, human