Prevalence of HEV RNA in Croatian blood donors

OBJECTIVES

HEV infection is asymptomatic for immunocompetent blood donors (BD). Transfused HEV-infected blood products may cause potentially hazardous HEV infection in immunocompromised patients. Evaluation of the need for routine BD HEV RNA screening primarily demands the establishment of HEV infection prevalence in Croatian BD.

MATERIALS AND METHODS

We tested BD samples in ID-NAT with the Procleix UltrioPlex E screening test for simultaneous detection of HBV DNA, HCV RNA, HIV-1,2 RNA, and HEV RNA (Grifols, Spain). HEV infection was confirmed with HEV RNA quantitative test (Altona Diagnostics, Germany) and HEV IgM and HEV IgG antibody test (DIA.PRO Diagnostic Bioprobes, Italy). We analysed the HEV RNA sequence and performed a phylogenetic analysis. We recorded BD's anamnestic data and dietary habits. BDs gave follow-up samples after two months and did not donate blood for six months.

RESULTS

Between December 2021 and March 2022, we tested 8,631 donations and found four HEV RNA-positive donations, which equals to one in 2,158 donations (0.046 %, 95 % confidence interval, 0.018 %-0.119 %). Confirmatory HEV RNA testing gave results from negative to 4.73E + 3 IU/ml HEV RNA. Three donations were in the serological window period. We have genotyped HEV RNA of two infected BD as genotype HEV-3c. Blood donors didn't report any health problems and their diet included pork. Testing on follow-up samples presented seroconversion and no HEV RNA could be detected.

CONCLUSION

The incidence of HEV RNA infection in BD in Croatia corresponds with other European data. The decision on implementation of HEV NAT screening in Croatia needs an expert team evaluation of the possible risk of TT-HEV infection.

Prenatal RHD genotyping in Croatia: preliminary results

OBJECTIVES

Croatian Institute of Transfusion Medicine (CITM) implemented non-invasive fetal RHD genotyping as a request for targeted antenatal anti-D prophylaxis. The diagnostic performance of in-house RT-PCR method for fetal RHD genotyping and preliminary results are analyzed.

MATERIALS AND METHODS

Evaluation included results of RHD genotyping for 205 RhD negative pregnant women, 12-36th week of gestation, whose samples were received in period between 2015 and 2020. QIAsymphony SP DSP Virus Midi Kit was used for cffDNA extraction on QIAsymphony SP platform (Qiagen, Germany). Fragments of RHD exons 7 and 10 and later exon 5 were RT-PCR amplified. As internal controls, amplification of SRY gene or RASSF1A fragment and β-actin genes digested with BsTUI were used.

RESULTS

We identified 70.72% (145/205) positive and 28.78% (59/205) negative fetal RHD genotypes. We had one inconclusive result (0.50%) due to the interference of maternal DNA with variant genotype RHD*09.02.00/01/*01N.01. When compared to newborns RhD phenotypes, no false negative and three false positive results (3/199, 1.50%) were observed. The test yielded 100% sensitivity and 95.08% specificity, while diagnostic accuracy was 98.48%. We were able to determine one case of fetal variant genotype RHD*04.04/*01N.01 inherited from the father. The negative and positive predictive test values were 100% and 97.86%, respectively.

CONCLUSION

Automated cffDNA extraction and RT-PCR amplification of fetal RHD exons 5,7,10 and fragments of SRY, RASSF1A genes represents highly reliable system for determining fetal RHD status which enables targeted antenatal anti-D prophylaxis. To obtain high specificity of cffDNA extraction, strict and thoroughly cleaning procedures are required.

RT-PCR detection of tyrosinase, gp100, MART1/Melan-A, and TRP-2 gene transcripts in peripheral blood of melanoma patients

AIM

To detect the expression of genes encoding tyrosinase, gp100, MART-1/Melan A, and tyrosinase-related protein-2 (TRP-2) in peripheral blood of melanoma patients by reverse transcription-polymerase chain reaction (RT-PCR).

METHODS

Nineteen peripheral blood samples were obtained from 17 melanoma patients. When tested, 15 of them presented with clinically detectable metastatic disease. Samples of peripheral blood (7 mL) were collected from each patient into vacutainer cell preparation tubes. Mononuclear cells were isolated, total cellular RNA extracted, and then used as a template for reverse transcription to complementary DNA (cDNA). The cDNA was thereafter assayed by PCR for the expression of melanocyte-associated transcripts of tyrosinase, gp100, MART1/Melan-A, and TRP-2 genes.

RESULTS

Gp100 gene expression was detected in 13 out of 19 samples. In 4 of them, TRP-2 gene expression was also detectable. Expression of tyrosinase and Melan-A/MART-1 genes could not be observed. Interestingly, gp100 and TRP-2 gene transcripts were detected in patients having recurrent and/or metastatic disease at the time of testing.

CONCLUSION

The results we obtained support the use of RT-PCR assay for indirect detection of melanoma cells in peripheral blood of melanoma patients. As the transcripts for the tyrosinase gene and MART-1/Melan A gene were not detected, additional optimization experiments of RT-PCR assay are required.

Hypervariable region 1 of hepatitis C virus genome and response to interferon therapy

The relationship between the complexity of the hypervariable region 1 (HVR1) quasispecies of hepatitis C virus (HCV) and responsiveness to interferon-alpha (IFN) therapy was studied in patients with chronic hepatitis C. Twelve HCV-RNA-positive patients were treated daily with high dose IFN and ribavirin for 4 weeks, and then with IFN 3 MIU (Million International Units) TIW (three times per week) and ribavirin for 6 months. The HVR1 quasispecies complexity was analyzed by nested polymerase chain reaction-mediated single-strand conformation polymorphism (SSCP). The baseline HCV-RNA levels in the study group ranged from 10(6) to 10(7) copies/ml. All patients exhibited HCV genotype 1 b. Initial SSCP analysis revealed four (33.3%) patients with a low complexity pattern (SSCP bands < or =4) and eight (66.6%) patients with high complexity pattern (SSCP bands >4). After 4 weeks of IFN therapy, one patient became HCV negative, and among those remaining positive, the HCV-RNA levels decreased by 2 to 3 logs and the number of SSCP decreased by 2 to 3 bands per sample. After 6 months of IFN therapy, five (41.7%) patients became HCV-RNA-negative. Seven (58.3%) patients did not respond to IFN therapy with sustained viral load from 10(3) to 10(5) copies/ml, and high complexity SSCP patterns. Our data support the HVR quasispecies complexity to be an independent predictive factor for IFN responsiveness in patients infected with HCV.