Dizili Yelgin, C; Gülhan, B; Yazgı, H

Dabanlioǧlu, Bülent; Yilmaz, Aysun; Akyüz, Sümeyye; Gülhan, Bariş

Introduction: The measurement of hepatitis C virus (HCV) RNA is a test that requires high cost, advanced technique, and qualified personnel. Diagnosis and treatment of patients may be delayed due to the high rate of false-positive results. This study aims to predict true antibody positivity and viremia by determining the most appropriate anti-HCV signal-to-cutoff (S/Co) value reflecting HCV infection. Methodology: The presence of anti-HCV antibodies and HCV RNA levels were examined in 72341 people who applied to the Mengücek Gazi Training and Research Hospital between January 2018 and December 2020. The anti-HCV levels were determined by using the Abbot Architect i2000 SR device (Abbot Diagnostics, Chicago, IL, USA). The levels of HCV RNA were determined in the COBAS AmpliPrep/COBAS, TaqMan 48 (Roche, Diagnostics, Pleasanton, USA) devices using serum samples from patients. Our study is a retrospective and methodological study. Results: Of the 150 patients with anti-HCV antibodies, 50 (33.3%) were HCV RNA positive, and 100 (66.7%) were HCV RNA negative. Anti-HCV levels of HCV RNA-positive patients were statistically higher than HCV RNA-negative patients. The most appropriate anti-HCV S/Co value for diagnosing hepatitis C patients was 15.4. The sensitivity of this value was 72%, specificity 88%, positive predictive value (PPV) 73.5%, and negative predictive value (NPV) 86.1%. Receiver operating characteristic (ROC) curve was significantly higher than 0.5 (95% confidence interval 0.938-0.827). Conclusions: Correct approaches can be applied in the diagnosis of HCV infection using the anti-HCV S/Co value found in our study.

Gulhan, Baris; Aydin, Merve; Demirkazik, Mehtap; Koltas, Ismail Soner; Cikman, Aytekin; Turkmen, Kultigin; Duran, Tugce

Introduction: The aim of this study was to determine the Blastocystis prevalence and subtypes in hemodialysis patients in Turkey. Methodology: Eighty-four patients diagnosed with end-stage renal failure who were undergoing hemodialysis and 20 healthy volunteers were enrolled. Blastocystis presence was investigated by native-Lugol, trichrome staining, PCR using STS primers, and DNA sequencing analysis. Results: Among the stool samples from the hemodialysis patients, 9.52% (8/84) were found to be Blastocystis-positive with the native-Lugol and trichrome staining. Seven of the eight Blastocystis isolates were subtyped using STS primers. Blastocystis subtype distribution was as follows: one had ST1, two had ST2, two had ST3, two had ST3+ST6, and one was not subtyped. Blastocystis positivity was detected in two healthy control (2/20, %10), one subject had ST1, and the other was not subtyped. All subtypes identified by PCR were confirmed by the sequencing analysis. In the two samples that had mixed subtypes (ST3+ST6) when using the STS primers, only ST3 was detected in the sequencing analysis. Although some patients have multiple symptoms, the most common symptoms in Blastocystis positive patients were bloating (5/8), diarrhea (4/8), nausea and vomiting (2/8), and gas and weight loss (1/8). Also, only one patient had Giardia intestinalis. Conclusions: This was the first study to determine the Blastocystis subtypes in hemodialysis patients. A rare subtype, ST6, was identified in two of the patients. Thus, the ST6 infections were attributable to transmission from poultry infections. The presence of this unusual subtype suggests the need for further extensive studies of hemodialysis patients.