Abstract
Purpose: :
Leptin is an adipose derived 167–amino acid large vasoactive protein whose receptor is a member of the class I cytokine receptor family and is known to be influenced by proinflammatory cytokines. This study evaluated serum leptin levels in patients with autoimmune uveitis
Methods: :
Serum samples from 30 patients with uveitis seen at the NEI and age–sex matched 14 controls were tested for leptin levels using ELISA. Flow cytometry was used to assess the expression of naïve and memory T lymphocyte subpopulations and activation markers. A complete ophthalmic exam, duration, type, etiology of uveitis, clinical activity, FA evidence of inflammation, and immunosuppressive agents were recorded for all patients. Body mass index was recorded for patients and normal controls.
Results: :
Of the 30 patients 17 were female and 13 male. There were 9 patients with sarcoidosis, 7 behcet’s disease, 10 idiopathic uveitis, 2 birdshot retinochoroidopathy, 1 PIC and 1 with VKH syndrome. Eight patients had clinically active uveitis at the time of enrollment whereas 19 had FA evidence of active inflammation. Mean serum leptin level was 31.84 (median:25.8) for patients and 20.07 (median:10.5) for control subjects. When adjusted for BMI there was no significant difference in serum leptin levels between patients and healthy controls (p:0.70). Although patients with active disease had higher leptin levels, there was no significant difference between patients with active and inactive disease. Patients who had uveitis for more than 5 years had higher levels of leptin compared to normal controls (p:0.05), and patients who had uveitis for more than 10 years had higher levels compared to those who had it for less than 10 years (p:0.05). Serum leptin levels were significantly lower in patients that were on ≤1 immunosuppressive agent compared to those who were on ≥2 immunosuppressive agents when adjusted for the duration of disease (p:0.03). An integrated flow cytometry analysis showed no significant difference in CD45 RA+, CD45 RO+ or CD69+ T lymphocyte subpopulations between uveitis patients and normal controls.
Conclusions: :
This study indicates that serum leptin levels may be elevated particularly in patients with longstanding intraocular inflammation. Patients using ≥2 immunosuppressive agents tend to represent a more severe disease course requiring more immunosuppression and thus may have higher serum leptin levels. Larger longitudinal studies are required to assess the association of serum leptin levels and immunosuppressive therapy in patients with uveitis.
Keywords: uveitis-clinical/animal model • cytokines/chemokines • flow cytometry