Soluble CD163 and interleukin-6 are increased in aqueous humour from patients with endothelial rejection of corneal grafts.
OBJECTIVE
To evaluate soluble CD163 (sCD163) as a new marker of macrophage activity in aqueous humour from patients with corneal rejection and to investigate correlations between sCD163, the CD163 inducing interleukin-6 (IL-6), and albumin; to investigate whether increases in sCD163 and IL-6 levels in aqueous humour were results of intra- or extraocular production, and to investigate the impact of sCD163 and IL-6 levels on graft outcome.


METHODS
Aqueous humour was obtained from 19 patients with endothelial rejection of corneal grafts, seven cataract patients and five cataract patients with uncomplicated corneal grafts. The presence of sCD163 was investigated by immunoprecipitation and immunoblotting. The concentrations of sCD163, IL-6 and albumin were measured by ELISA.


RESULTS
Soluble CD163 was detected in aqueous humour from patients with corneal rejection. Soluble CD163, IL-6 and albumin were significantly increased in aqueous humour from patients with corneal rejection when compared with control patients. When normalizing sCD163 and IL-6 with albumin, the differences between rejection patients and control groups became insignificant for sCD163 but remained significant for IL-6. Neither IL-6 nor sCD163 were related to the outcome of the corneal rejection.


CONCLUSIONS
Both sCD163 and IL-6 are present in high levels in aqueous humour from patients with rejection of corneal grafts. Our data suggest that IL-6 is produced locally, whereas sCD163 is at least partly derived from influx from plasma.
Funding
Mikkel
M
Department of Ophthalmology, Aarhus University Hospital, Aarhus, Denmark. mfd@akhphd.au.dk
Vorum
Henrik
H
Nexø
Ebba
E
Moestrup
Søren Kragh
SK
Ehlers
Niels
N
Møller
Holger Jon
HJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism*; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism*; D001082:Aqueous Humor / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D016039:Corneal Transplantation; D004728:Endothelium, Corneal / Q000378:metabolism* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006084:Graft Rejection / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000378:metabolism*; D012995:Solubility; D000098902:CD163 Antigen
D000418:Albumins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D000098902:CD163 Antigen; D015850:Interleukin-6; D011956:Receptors, Cell Surface