title: Soluble CD163 levels are elevated in cerebrospinal fluid and serum in people with Type 2 diabetes mellitus and are associated with impaired peripheral nerve function.
abstract: OBJECTIVE
  To measure soluble CD163 levels in the cerebrospinal fluid and serum of people with Type 2 diabetes, with and without polyneuropathy, and to relate the findings to peripheral nerve function.
  
  
  METHODS
  A total of 22 people with Type 2 diabetes and 12 control subjects without diabetes were included in this case-control study. Participants with diabetes were divided into those with neuropathy (n = 8) and those without neuropathy (n = 14) based on clinical examination, vibratory perception thresholds and nerve conduction studies. Serum and cerebrospinal fluid soluble CD163 levels were analysed using an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Soluble CD163 levels were significantly higher in the cerebrospinal fluid and serum of the participants with Type 2 diabetes compared with the control participants [cerebrospinal fluid: median (range) 107 (70-190) vs 84 (54-115) μg/l, P < 0.01 and serum: 2305 (920-7060) vs 1420 (780-2740) μg/l, P < 0.01). Cerebrospinal fluid soluble CD163 was positively related to impaired peripheral nerve conduction (nerve conduction study rank score: r = 0.42; P = 0.0497) and there was a trend for higher levels of soluble CD163 in the cerebrospinal fluid and serum in participants with neuropathy than in those without neuropathy [cerebrospinal fluid: median (range) 131 (86-173) vs 101 (70-190) μg/l, P = 0.08 and serum: 3725 (920-7060) vs 2220 (1130-4780), P = 0.06).
  
  
  CONCLUSIONS
  Cerebrospinal fluid soluble CD163 level is associated with impaired peripheral nerve function. Higher levels of soluble CD163 in people with diabetic polyneuropathy suggest that inflammation plays a role in the development of neural impairment. The relationship between cerebrospinal fluid soluble CD163 level and peripheral nerve conduction indicates that soluble CD163 may be a potential biomarker for the severity of diabetic polyneuropathy.
authors.affiliation: Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Kallestrup
authors.forename: H J
authors.initials: HJ
authors.lastname: Møller
authors.forename: H
authors.initials: H
authors.lastname: Tankisi
authors.forename: H
authors.initials: H
authors.lastname: Andersen
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000097:blood* / Q000134:cerebrospinal fluid*; D015214:Antigens, Differentiation, Myelomonocytic / Q000097:blood* / Q000134:cerebrospinal fluid*; D015415:Biomarkers / Q000097:blood / Q000134:cerebrospinal fluid; D015992:Body Mass Index; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000134:cerebrospinal fluid / Q000503:physiopathology*; D003929:Diabetic Neuropathies / Q000097:blood / Q000134:cerebrospinal fluid / Q000503:physiopathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000134:cerebrospinal fluid / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction; D011956:Receptors, Cell Surface / Q000097:blood*; D000098902:CD163 Antigen
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D000098902:CD163 Antigen; D011956:Receptors, Cell Surface