Background and importance Inflammation is involved in the development and pathogenesis of age-related macular degeneration (n-AMD) although the roles that the inflammation-related cytokines play in it are not yet defined as some of them are pro-angiogenic. Local and systemic inflammatory molecules are being proposed as potential biomarkers of n-AMD progression.

Aim and objectives The aim of this study was to evaluate cytokine values after the ranibizumab loading phase in patients with n-AMD.

Material and methods Prospective, observational study of n-AMD patients with criteria to initiate treatment with ranibizumab. A blood test was performed at the initial visit (prior to the first administration of ranibizumab) and after finishing the loading doses (4 months). Demographic, clinical and blood analytical parameters (C-reactive protein (CRP), β2-microglobulin, tumour necrosis factor (TNF), interleukins rIL-2, IL-5, IL-6, IL-8 and IL-10) were obtained through electronic medical records. Statistical analysis was performed using Student’s t-test (SPSS Statistics V.26, IBM Inc.).

Results A total of 45 patients were included (40% men). Mean age was 80±8 years. 41 patients responded to treatment (14 partially), 2 did not respond to treatment and 2 did not finished the loading phase. Visual acuity obtained a statistically significant improvement in responder patients (EDTRS: 56±17 vs 63±16, p<0.002).

In responders, changes in cytokine serum levels did not reach statistically significant differences between the initial visit and after the loading phase (p>0.05): TNF (8.97±2.78 vs 9.04±3.75 pg/mL), CRP (0.323±0.387 vs 0.324±0.332 mg/dL), β2-microglobulin (2.77±0.92 vs 2.85±0.95 mg/L), IL-6 (6.6±3.3 vs 6.5±6.1 pg/mL), rIL-2 (516.0±213.9 vs 529.6±224.9 U/mL). Although IL-8 (51.46±66.5 vs 85.95±115.1 pg/mL) showed an increase after the loading phase, it did not reach statistical significance (p=0.088). IL-5 and IL-10 remained undetected over time in both responders and non-responder patients.

Conclusion and relevance Changes at the end of the loading phase in IL-6 and IL-8 have been described previously with the administration of anti-angiogenics. In our case, no differences were detected, probably due to the low sample size. More studies will be necessary to determine the prognostic potential of the change in systemic cytokines as a response parameter in patients treated with anti-angiogenics in AMD.

References and/or acknowledgements This study was partially supported by Health Institute Carlos III and co-financed by FEDER (PI17/00940, RETICS Oftared, RD16/0008/0003, RD12/0034/0017)

Conflict of Interest No conflict of interest