Biological variation of serum neopterin concentrations in apparently healthy individuals.

OBJECTIVES: The aims of this study were to determine the biological variation (BV), reference change value (RCV), index of individuality (II), and quality specifications for serum neopterin concentrations; a measurand provided by clinical laboratories as an indicator of cellular immunity. METHODS: The study delivered serum samples collected for 10 consecutive weeks from 12 apparently healthy individuals (3 male, 9 female). Serum neopterin concentrations were measured using high-performance liquid chromatography with fluorometric detection. The data analysis was performed using an online statistical tool and addressed published criteria for estimation of biological variation. RESULTS: The mean neopterin concentration was 5.26 nmol/L. The within-subject biological variation (CVI) with 95 % confidence interval (CI) of neopterin serum concentrations was 11.54 % (9.98-13.59), and the between-subject biological variation (CVG) with 95 % CI was 43.27 % (30.52-73.67). The neopterin asymmetrical RCV was -24.9 %/+33.1 %, and the II was 0.27. The desirable quality specifications for neopterin were <5.77 % for precision, <11.20 % for bias, and <20.72 % for total allowable error (TEa). When analytical variation was used instead of CVI to calculate TEa, the desirable TEa was <18.39. CONCLUSIONS: This study determined BV data for neopterin, an indicator of cell-mediated immune response. Asymmetric RCV values, of 24.9 % decrease or a 33.1 % increase between consecutive measurements indicate significant change. The II of 0.27 indicates a high degree of individuality, therefore that it is appropriate to consider the use of personal reference data and significance of change rather than the reference interval as points of reference for the evaluation of neopterin serum concentrations.

Serum Levels of miR-223-3p and miR-223-5p in Prostate Diseases.

INTRODUCTION: Prostate Cancer (PCa) is the second most common cancer in males and the fifth in cancer-associated mortality. Although the Prostate-Specific Antigen (PSA) test is widely used in PCa screenings, it has significant limitations in the differential diagnosis of PCa. Therefore, studies on developing new biomarkers for PCa diagnosis are ongoing. MiRNAs are good candidate biomarkers for the diagnosis of cancers, including prostate cancer, as they can be easily detected from circulation. OBJECTIVE: In this study, it is aimed to determine the diagnostic value of serum levels of miR-223-3p and -223-5p in Benign Prostate Hyperplasia (BPH), Chronic Prostatitis (CP) and Prostate Cancer (PCa). METHODS: Serum samples were collected from 68 patients in total (25 BPH, 10 CP, 33 PCa). MiR-223- 3p and -223-5p levels were measured in serum with qRT-PCR. The Ct values of miRNAs were normalized according to the Ct value of ce-miR-39 and calculated -ΔCt values were used for statistical analyses. RESULTS: The serum levels of miR-223-3p and -223-5p were downregulated in the PCa and CP groups, compared to the BPH group. There was no statistically significant difference between PCa and CP groups. The sensitivity and specificity of miR-223-3p, -223-5p and their combination were calculated as 88% and 88%; 86% and 79%; 93% and 92% in discriminating BPH and PCa groups, respectively. CONCLUSION: In this study, it was shown that miR-223-3p and -223-5p were both detectable in circulation. miR-223-3p, -223-5p, and their combination may be good candidate biomarkers for prostate cancer diagnosis. Also, observation of similar serum levels of miR-223-3p and -223-5p between CP and PCa groups suggests that miR-223 may play a role in prostate cancer development originated from chronic inflammation.