Professor Danilo Donizete da Silva (São José do Rio Preto / BR), Dr. Geraldo Magela de Faria Júnior (São José do Rio Preto / BR), Dr. Fábio Batista Frederico (São José do Rio Preto / BR), Dr. Rubens Camargo Siqueira (São José do Rio Preto / BR), Dr. Lilian Castiglioni (São José do Rio Preto / BR), Dr. Cinara de Cássia Brandão (São José do Rio Preto / BR), Dr. Luiz Carlos de Mattos (São José do Rio Preto / BR), Dr. Christiane Maria Ayo (São José do Rio Preto / BR)
Introduction: Ocular toxoplasmosis (OT), one of the common clinical manifestations of Toxoplasma gondii infection, is characterized by an intraocular inflammatory process (retinochoroiditis). Affected patients may have increased intraocular pressure (IOP). Variations in the expression of microRNAs (miRNAs) can result in specific immunological alterations in infected ocular tissues.
Objectives: This study correlated the expression of miR_511_5p with IOP in patients with and without OT.
Materials and methods: Patients were grouped into G1: With active ocular lesions and seropositive (n=33); G2: With ocular scars and seropositive (n=16); G3: Without ocular lesions and scars and seropositive (n=21) and G4: Without lesions or scars and seronegative (n=24). The presence of anti-T. gondii IgM and IgG antibodies were determined using the ELFA test. MiRNA was extracted from peripheral blood, and miRNA 511_5p was amplified by real-time PCR. Ocular characteristics were obtained from medical records and organized into right eye (RE) and left eye (LE). Non-parametric Kruskal-Wallis and ANOVA tests were used to compare the variables; Pearson's test was used to estimate the correlation between the mean expression of miRNA 511_5p and IOP values, adopting a significance level of 5%.
Results and Discussion: In G1 the mean age was 39.48±14.43 (range:19-67); in G2 the mean age was 43.31±14.59 (range: 22-65); in G3 it was 58.29±13.33 (range: 24-78); and in G4 it was 66.08±7.98 (range:53-83). There was a statistically significant difference in relation to the mean age (G1xG3= p<0.001, t=4.8, df=52; G1xG4= p<0.001, t=8.15, df=55; G2xG3= p<0.05, t=3.5, df=35 and G2xG4= p<0.001, t=6.37, df=38). The mean expression of miR 511-5p in G1 was 21.67 ± 13.67 and statistically higher than in the other groups (p<0.001). In G1, the expression of miR 511_5p was related to a higher mean IOP value in the LE (p=0.04; CI=0.014-0.66). These results demonstrate that the expression of miRNA 511_5p is elevated in patients with active ocular damage and reactive serology for T. gondii, and correlates with IOP. It is possible that the 511_5p miRNA influences the clinical evolution of OT. These observations may contribute to the creation of new therapeutic strategies.
Conclusion: The microRNA 511_5p can act as a biological marker for the prognosis of OT and IOP.
Keywords: microRNA, ocular toxoplasmosis, intraocular pressure, ophthalmology.