Circulating MicroRNAs as Biomarker for Vessel-Associated Retinal Diseases.

INTRODUCTION: Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, noncoding ribonucleic acids that are involved in the posttranscriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in the serum and vitreous of human patients with and without vessel-associated retinal diseases. METHODS: Relative quantification by quantitative real-time polymerase chain reaction was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinal vein occlusion compared with control patients. RESULTS: In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in receiver operating characteristic (ROC) and area under the ROC curve analysis. CONCLUSION: The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis.

C/D Ratio in Long-Term Renal Function.

BACKGROUND/AIMS: Tacrolimus is an immunosuppressive drug. Its C0 concentration, commonly used for monitoring, does not always correspond to its pharmacologic effect. Thölking et al developed an indicator, the C/D ratio, that describes the drug's metabolism rate. Our purpose was to determine whether the points dividing the patients into fast, intermediate, and slow metabolizers that were assumed by those authors would be similar for long-term follow-up after renal transplantation (RTx). METHODS: We examined the C/D ratio in 571 patients at their most recent appointments-1 year and more after renal transplantation. The mean time after RTx was 84 months. We studied kidney function both at the most recent appointment and early after RTx. RESULTS: The median C/D ratio for our group was 1.68. Our observations revealed a negative correlation between the C/D ratio and creatinine concentration and a positive correlation between the C/D ratio and eGFR concentration long term after RTx. We formulated a C/D ratio cutoff point between an eGFR < and ≥ 60 mL/min/1.73 m2 and came up with the value of 1.53. It was found that between the < 1.53 and ≥ 1.53 groups, there were significant differences in creatinine and eGFR concentrations at the most recent appointment, as well as differences in how creatinine and eGFR levels varied over time between RTx and the most recent observation. CONCLUSIONS: The C/D ratio is useful for assessing the effect of the tacrolimus metabolism rate on long-term renal function. We propose the C/D ratio value of 1.53 as the cutoff point below which the ratio provides a negative prognosis for long-term renal function.