Intravitreal neurodegenerative and inflammatory mediators in proliferative diabetic retinopathy

Mallmann, Felipe; Canani, Luis Henrique

ABSTRACT Purpose:

To compare the intravitreal concentrations of cellular mediators involved in neurodegeneration, inflammation, and angiogenesis in patients with proliferative diabetic retinopathy and other vitreoretinal diseases.

Methods:

A multiplex bead immunoassay was used to measure vitreous levels of pigment epithelium-derived factor, serum amyloid P, C-reactive protein, complement C4, alpha-1 antitrypsin, vascular endothelial growth factor, platelet-derived growth factor-AA, platelet-derived growth factor-BB, interleukin-6, interleukin-8, interleukin-10, tumor necrosis factor alpha and beta in patients undergoing 23-gauge vitrectomy for proliferative diabetic retinopathy and other diagnoses (control group).

Results:

We evaluated 55 patients, of whom 24 had proliferative diabetic retinopathy and 31 had other diagnoses including vitreous hemorrhage, retinal detachment, macular hole, and epiretinal membrane. Patients with proliferative diabetic retinopathy demonstrated increased levels of serum amyloid P (85.49 vs. 31.38 ng/mL); C-reactive protein (59.89 vs. 41.75 ng/mL), vascular endothelial growth factor (2,330.11 vs. 554.25 pg/mL; p<0.001), platelet-derived growth factor A (127.32 vs. 39.11 pg/mL), platelet-derived growth factor B (29.37 vs. 7.12 pg/mL), interleukin-6 (69.37 vs. 33.58 pg/mL), interleukin-8 (175.25 vs. 59.71 pg/mL), and interleukin-10 (3.70 vs. 1.88 pg/mL); all p<0.004 when compared with the control group. Levels of pigment epithelium-derived factor (30.06 vs. 27.48 ng/mL; p=0.295), complement C4 (570.78 vs. 366.24 ng/mL; p=0.069), and alpha-1-antitrypsin (359.27 vs. 522.44 ng/mL; p=0.264) were not significantly different between the groups. Intravitreal levels of tumor necrosis factor-alpha and tumor necrosis factor-beta were undetectable. Serum Amyloid P, C-reactive protein, platelet-derived growth factor A, platelet-derived growth factor B, interleukin-6, and interleukin-8 were correlated positively with vascular endothelial growth factor.

Conclusions:

Cellular mediators involved in neurodegeneration and inflammation demonstrated increased levels in the vitreous humor of patients with proliferative diabetic retinopathy and may be part of the pathogenesis of diabetic retinopathy.

RESUMO Objetivo:

Comparar as concentrações intravítreas de mediadores celulares envolvidos na neurodegeneração, inflamação e angiogênese em pacientes com retinopatia diabética proliferativa e outras doenças vítreo-retinianas.

Métodos:

Um ensaio imunomagnético foi utilizado para medir os níveis vítreos do fator derivado do epitélio pigmentar, amilóide P sérico, proteína-C-reativa, complemento C4, e alfa-1-antitripsina, fator de crescimento do endotélio vascular, fator de crescimento derivado das plaquetas AA, fator de crescimento derivado das plaquetas BB, interleucina-6, interleucina-8, interleucina-10, fator de necrose tumoral alfa e beta em pacientes submetidos à vitrectomia 23-gauge para retinopatia diabética proliferativa ou outros diagnósticos (grupo controle).

Resultados:

Foram avaliados 55 pacientes, dos quais 24 tinham retinopatia diabética proliferativa e 31 tinham outros diagnósticos, incluindo hemorragia vítrea, descolamento de retina, buraco macular e membrana epirretiniana. Pacientes com retinopatia diabética proliferativa demonstraram níveis aumentados de amilóide P sérico (85,49 vs 31,38 ng/mL), proteína-C-reativa (59,89 vs 41,75 ng/mL), fator de crescimento do endotélio vascular (2.330,11 vs 554,25 pg/mL, p<0.001), fator de crescimento derivado das plaquetas-A: (127,32 vs 39,11 pg/mL), fator de crescimento derivado das plaquetas-B (29,37 vs 7,12 pg/mL), interleucina-6 (69,37 vs 33,58 pg/mL), interleucina-8 (175,25 vs 59,71 pg/mL) e interleucina-10 (3,70 vs 1,88 pg/mL), todos com p<0,004 quando comparados ao grupo controle. Níveis de fator derivado do epitélio pigmentar (30,06 vs 27,48 ng/mL; p=0,295), complemento C4 (570,78 vs 366,24 ng/mL; p=0,069), alfa-1 antitripsina (359,27 vs 522,44 ng/mL; p=0,264) não foram significativamente diferente entre os grupos. Níveis intravítreos de fator de necrose tumoral alfa e fator de necrose tumoral beta foram indetectáveis. O amilóide P sérico, a proteína C-reativa, o fator de crescimento derivado das plaquetas A e B, a interleucina-6 e a interleucina-8 correlacionaram-se positivamente com o fator de crescimento do endotélio vascular.

Conclusões:

Os medidores celulares envolvidos na neurodegeneração e inflamação demonstraram níveis aumentados no humor vítreo de pacientes com retinopatia diabética proliferativa e podem ser parte da patogênese da retinopatia diabética.