Comprehensive analysis of vitreous specimens for uveitis classification: a prospective multicentre observational study

Purpose: To determine the clinical relevance of vitreous biomarkers in uveitis patients.
Design: Multicentre, prospective, observational study.
Setting: Uveitis outpatient clinics of two academic medical centres in Japan.
Patient Population: This study included 234 eyes of 191 patients with various uveitis aetiologies: definitive sarcoidosis (61 eyes of 46 patients), suspected sarcoidosis (60 eyes of 45 patients), intraocular tumour (34 eyes of 27 patients), viral infection (20 eyes of 18 patients), non-sarcoidosis (16 eyes of 16 patients), and unknown aetiology (43 eyes of 39 patients).
Observation Procedure: Vitreous samples (taken by pars planta vitrectomy) were analysed with flow cytometry, cytology, and multiplex PCR analysis.
Main Outcome Measures: The primary outcome measures were the diagnostic values of various biomarkers (T-cells, B-cells and pathogen DNA) in vitreous samples. The secondary outcome was visual acuity after vitrectomy.
Results: Sarcoidosis showed higher CD4/CD8 or CD4+ measurements than other aetiologies (p<0.01). In samples with viral infection, pathogen DNA was detected, and CD8+ counts were higher than the other aetiologies (p<0.01). Eyes with tumour had higher CD19+ (p<0.05). Non-sarcoidosis had lower CD4/CD8 than sarcoidosis, higher CD8+ than sarcoidosis, and lower CD19+ than tumour (p<0.01). Unknown uveitis had lower CD4/CD8 than sarcoidosis (p<0.01), and higher CD4/CD8 than non-sarcoidosis, viral infection, or tumour (p<0.001). Visual acuity improved after vitrectomy (p<0.001).
Conclusions: Uveitis aetiologies had distinct vitreous biomarker profiles, especially of infiltrating lymphocytes., Analyses of CD4/CD8 ratio, T- and B-lymphocyte subset, and pathogen DNA in vitreous samples have good safety profiles and high diagnostic value for uveitis classification.