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Background Until now, markers of hepatitis E virus (HEV) infection have not been studied in blood donors throughout Poland, and no acute case of HEV infection has been closely documented or confirmed by HEV RNA detection. The prevalence of HEV infection markers, including HEV RNA in Polish blood donors and virus genotypes was investigated. Study design and methods In total, 12,664 individual donations from 22 Polish blood transfusion centers were tested for HEV RNA by transcription-mediated amplification. In addition, 3079 first-time donors sampled throughout Poland also were screened for antibodies to HEV. HEV RNA and immunoglobulin M-positive donations were confirmed using real-time reverse transcription-polymerase chain reaction and Western blotting, respectively. Results Ten donors were identified as RNA initial reactive (one of 1266 donors), and six (one of 2109) were identified as repeat reactive and confirmed by real-time reverse transcription-polymerase chain reaction or seroconversion. Sequence analysis identified HEV Genotype 3c in one donor and Genotype 3i in two others. On average, 43.5% of donors were immunoglobulin G-positive. Immunoglobulin G seroprevalence ranged from 22.7% to 60.8% in group ages 18 to 27 years and 48 to 57 years, respectively and differed between administrative regions from 28.9% in Podlasie to 61.3% in Wielkopolska. Thirty-nine of the donors were immunoglobulin M-positive, and seven donors were IgM positive only (0.2%). Of 37 immunoglobulin M-reactive samples tested by Western blot, 24 (64.9%) were confirmed. Conclusions The current results indicate a high level of HEV endemicity throughout Poland compared with other countries. There is an urgent need to consider the protection of recipients of blood components against transfusion-transmitted HEV infection.

Until now, markers of hepatitis E virus (HEV) infection have not been studied in blood donors throughout Poland, and no acute case of HEV infection has been closely documented or confirmed by HEV RNA detection. The prevalence of HEV infection markers, including HEV RNA in Polish blood donors and virus genotypes was investigated.In total, 12,664 individual donations from 22 Polish blood transfusion centers were tested for HEV RNA by transcription-mediated amplification. In addition, 3079 first-time donors sampled throughout Poland also were screened for antibodies to HEV. HEV RNA and immunoglobulin M-positive donations were confirmed using real-time reverse transcription-polymerase chain reaction and Western blotting, respectively.Ten donors were identified as RNA initial reactive (one of 1266 donors), and six (one of 2109) were identified as repeat reactive and confirmed by real-time reverse transcription-polymerase chain reaction or seroconversion. Sequence analysis identified HEV Genotype 3c in one donor and Genotype 3i in two others. On average, 43.5% of donors were immunoglobulin G-positive. Immunoglobulin G seroprevalence ranged from 22.7% to 60.8% in group ages 18 to 27 years and 48 to 57 years, respectively and differed between administrative regions from 28.9% in Podlasie to 61.3% in Wielkopolska. Thirty-nine of the donors were immunoglobulin M-positive, and seven donors were IgM positive only (0.2%). Of 37 immunoglobulin M-reactive samples tested by Western blot, 24 (64.9%) were confirmed.The current results indicate a high level of HEV endemicity throughout Poland compared with other countries. There is an urgent need to consider the protection of recipients of blood components against transfusion-transmitted HEV infection.

Background Cord blood (CB) is a valuable source of hematopoietic stem cells (HSCs). Extended storage of CB is possible provided that validated cryopreservation procedures are used. The study objective was to determine optimal methods of CB cryopreservation. Study design and methods In the study we 1) compared the effect of two-step cryopreservation and controlled-rate freezing method on the postthaw quality of CB (Study A) and 2) evaluated the postthaw quality of HSC fractions isolated from CB with various methods and frozen with controlled-rate freezing method (Study B). The same cryoprotectant mixture was used for 20 CB units (Study A) and 122 CB units (Study B). Results In Study A, 13.79 × 10(8) and 13.29 × 10(8) initial white blood cell (WBC) counts decreased to 6.38 × 10(8) and 6.02 × 10(8) after thaw for the two methods, respectively. The mononuclear cell (MNC) counts decreased from 5.90 × 10(8) to 3.71 × 10(8) and from 5.64 × 10(8) to 3.47 × 10(8) dependent on the method. MNC viability decreased from 99.0% to 97.4% for the former and from 98.5% to 97.2% for the latter method. The differences were insignificant. In Study B, postthaw WBC recovery in HSC fractions was 74.4% to 103.5%, MNC recovery 106.4% to 118.5%, CD34+ cell recovery 102.5% to 150.2%, and MNC viability 94.1% to 97.4%. Conclusion Neither the cryopreservation procedure nor the freezing of isolated HSCs affected product quality, which may indicate that various freezing methods can be used for cell banking provided the they follow recommendations of good manufacturing practice and Directive 2004/33/EC.

Cord blood (CB) is a valuable source of hematopoietic stem cells (HSCs). Extended storage of CB is possible provided that validated cryopreservation procedures are used. The study objective was to determine optimal methods of CB cryopreservation.In the study we 1) compared the effect of two-step cryopreservation and controlled-rate freezing method on the postthaw quality of CB (Study A) and 2) evaluated the postthaw quality of HSC fractions isolated from CB with various methods and frozen with controlled-rate freezing method (Study B). The same cryoprotectant mixture was used for 20 CB units (Study A) and 122 CB units (Study B).In Study A, 13.79 × 10(8) and 13.29 × 10(8) initial white blood cell (WBC) counts decreased to 6.38 × 10(8) and 6.02 × 10(8) after thaw for the two methods, respectively. The mononuclear cell (MNC) counts decreased from 5.90 × 10(8) to 3.71 × 10(8) and from 5.64 × 10(8) to 3.47 × 10(8) dependent on the method. MNC viability decreased from 99.0% to 97.4% for the former and from 98.5% to 97.2% for the latter method. The differences were insignificant. In Study B, postthaw WBC recovery in HSC fractions was 74.4% to 103.5%, MNC recovery 106.4% to 118.5%, CD34+ cell recovery 102.5% to 150.2%, and MNC viability 94.1% to 97.4%.Neither the cryopreservation procedure nor the freezing of isolated HSCs affected product quality, which may indicate that various freezing methods can be used for cell banking provided the they follow recommendations of good manufacturing practice and Directive 2004/33/EC.