Satoru Hino

Infectivity of blood components with low hepatitis B virus DNA levels identified in a lookback program

BACKGROUND: Japanese Red Cross (JRC) blood centers implemented anti‐hepatitis B core antigen (HBc) screening in 1989 and 50‐minipool (MP)‐nucleic acid testing (NAT) in 2000. A systematic lookback study has been conducted to determine the hepatitis B virus (HBV) transmission risk of donations drawn in the pre‐hepatitis B surface antigen (HBsAg) and/or MP‐NAT window phase and by donors with occult HBV infection.

Lengths of hepatitis B viremia and antigenemia in blood donors: preliminary evidence of occult (hepatitis B surface antigen-negative) infection in the acute stage.

BACKGROUND: The Japanese Red Cross (JRC) implemented a fully automated pooling and nucleic acid amplification test (NAT) system for testing seronegative donations. The JRC sample repository and repeat blood donations allowed for lookback and follow‐up studies of hepatitis B virus (HBV) DNA–positive donors, who tested negative for hepatitis B surface antigen (HBsAg) and anti–hepatitis B core antigen in the JRC screening system.

A nationwide survey for hepatitis E virus prevalence in Japanese blood donors with elevated alanine aminotransferase

BACKGROUND: Although we reported two cases of transfusion‐transmitted hepatitis E in Japan, the prevalence of hepatitis E virus (HEV) in Japanese blood donors is not very clear.

Residual risk of transfusion‐transmitted hepatitis B virus (HBV) infection caused by blood components derived from donors with occult HBV infection in Japan

BACKGROUND: Nucleic acid amplification testing (NAT) for hepatitis B virus (HBV) during blood screening has helped to prevent transfusion‐transmitted HBV infection (TT‐HBV) in Japan. Nevertheless, 4 to 13 TT‐HBV infections arise annually.

Symptomatic parvovirus B19 infection caused by blood component transfusion.

BACKGROUND: Although a risk of transfusion‐transmitted human parvovirus B19V (TT‐B19V) infection has been a concern, there have been very few reports of clinically relevant TT‐B19V caused by the transfusion of a B19V‐containing blood component. It has therefore been a matter of debate whether a universal B19V screening with an appropriate sensitivity is required.

No viremia of pandemic (H1N1) 2009 was demonstrated in blood donors who had donated blood during the probable incubation period

BACKGROUND: In the spring of 2009, the novel swine‐origin influenza A (pandemic [H1N1] 2009) virus emerged and spread globally. Although no established cases of transfusion‐transmitted influenza have been reported, the widespread outbreak of pandemic (H1N1) 2009 caused serious concern regarding the safety of blood products. The Japanese Red Cross Blood Centers have intercepted blood products with accompanying postdonation information indicating possible pandemic (H1N1) 2009 infection. To study the risk of transmission of pandemic (H1N1) 2009 by blood transfusion, we searched for the viral genome in such products using nucleic acid amplification technology.

First report of human immunodeficiency virus transmission via a blood donation that tested negative by 20-minipool nucleic acid amplification in Japan

The Japanese Red Cross (JRC) blood centers screen donated blood for infectious agents using serologic assays and nucleic acid amplification testing (NAT). A multiplex NAT for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus Type 1 (HIV-1) with a minipool (MP) format comprising 50 seronegative samples was started in 2000. During the implementation of the 50-MPNAT in 2003, HIV-1 was transmitted through fresh-frozen plasma (FFP) from one blood donor during the window period. To reinforce NAT screening, the pool size was decreased to 20 in 2004. Since 20-MP-NAT implementation in 2004, we have found 19 donations that were seronegative but positive for HIV in the 20-MP-NAT. The rate of HIV-infected donations that were positive only in the NAT was approximately 1 in 2.7 million. No transfusiontransmitted HIV infection (TT-HIV) has been reported in Japan since the 20-MP-NAT was introduced. In November 2013, anti-HIV was detected in a blood sample from a repeat male blood donor aged in his 40s. Western blotting (New LAV Blot 1, Bio-Rad, Hercules, CA), real-time reverse transcription–polymerase chain reaction assay (Cobas TaqScreen HIV, Roche, Basel, Switzerland), and transcription-mediated amplification assay using a kit (Procleix Ultrio ABD, Novartis Diagnostics, Emeryville, CA) confirmed HIV-1 infection. A qualitative NAT for HIV-1 (Cobas TaqMan, Roche) detected a plasma HIV-1 viral load of 4.7 × 10 copies/mL. A cryopreserved sample of plasma from his previous donation in February 2013 was retested in accordance with the Japanese guidelines for lookback studies on blood products. Using individual donation (ID-) NAT, the Cobas TaqScreen HIV (plasma input volume, 850 μL; 95% limit of detection [LOD], 24.3 IU/mL) detected HIV-1 RNA in an archived blood sample from his previous donation, whereas the Procleix (plasma input volume, 500 μL; 95% LOD, 19.6 IU/mL) did not. Each of these NAT assays was performed as a single test. The low plasma volume in the archival sample did not allow for repeat analysis. Red blood cell (RBC) and FFP components were prepared from the previous donation and transfused into two recipients. The RBCs were transfused to a female patient in her 80s. A pretransfusion sample and a posttransfusion sample collected 9 months after transfusion were HIV seronegative. The latter sample was also negative for HIV RNA. The FFP was transfused 8 months after donation to a male patient in his 60s, from whom a pretransfusion sample was seronegative for HIV. Serologic tests and NAT assay identified HIV-1 infection in this recipient at 34 days after transfusion, and the plasma HIV-1 viral load was 1.1 × 10 copies/mL (Fig. 1). The viral sequences determined in blood samples from both the donor (postseroconversion donation) and the FFP recipient differed by only one among 341 nucleotides in the env region (99.7% identity) and by four of 2800 nucleotides in the pol region (99.9% identity). Such high genetic similarity among the sequences supported the notion that HIV had been transferred from the donor to the FFP recipient. Isolates of HIV-1 from the donor and recipient were Subtype B, which is the most common among individuals infected with HIV-1 in Japan. Major antiretroviral drug-resistant mutations were not detected in either the donor or the recipient. Sequencing the HIV-1 5′-long terminal repeat, which was the target region of our NAT screen, did not detect HIV-1 mutations that caused false-negative NAT results. To estimate the HIV-1 viral load in the implicated blood, the sensitivity of both the Cobas TaqScreen HIV and the Procleix was reassessed by probit analysis using serial threefold dilutions (four replicates per dilution) of postseroconverted plasma (4.7 × 10 copies/mL) from the donor, which revealed that the 95% LOD of both NAT screens was 10 copies/mL. The archived blood sample from the implicated donation was reactive in the Cobas, but not in the Procleix screen; therefore, we speculated that the viral load in the donor plasma was approximately at the detection limit of the two NATs. Thus, the estimated total amount of HIV-1 in the FFP (containing

Risk for transmission of pandemic (H1N1) 2009 virus by blood transfusion.

To the Editor: Influenza A pandemic (H1N1) 2009 virus emerged in early 2009 in Mexico and has since spread worldwide. In Japan, the first outbreak of the novel influenza was reported in May 2009 (1) and became pandemic in November. Although no cases of transfusion-transmitted influenza have been published, evidence exists of brief viremia before onset of symptoms (2,3). The possibility of transmission of this virus through transfusion of donated blood is of concern. The Japanese Red Cross Blood Centers have intercepted blood products with accompanying postdonation information indicating possible pandemic (H1N1) 2009 infection and attempted to identify the viral genome in those products by using nucleic acid amplification technology (NAT). During June–November 2009, blood samples were collected from plasma and erythrocyte products that had been processed from donations; postdonation information indicated diagnosis of pandemic (H1N1) 2009 infection soon after donation. Viral RNA was extracted from plasma samples and erythrocyte fractions by using a QIAamp Virus Biorobot MDx kit (QIAGEN, Valencia, CA, USA) and a High Pure Viral Nucleic Acid Large Volume kit (Roche Diagnostics, Indianapolis, IN, USA), respectively. RNA samples were subjected to real-time reverse transcription–PCR (RT-PCR) of hemagglutinin (HA) and matrix (M) genes of influenza A by using PRISM 7900 (Applied Biosystems, Foster City, CA, USA). The RT-PCR of HA was specific for pandemic (H1N1) 2009 virus, whereas the RT-PCR of M was designed to detect both pandemic (H1N1) 2009 and seasonal influenza A viruses. The sequences of probes and primers were synthesized according to the protocols developed by the Japanese National Institute of Infectious Diseases (4). Either 200 μL of a plasma sample or 100 µL of packed erythrocytes was used for each test, and the test was performed 2× for each gene in each sample. Before the investigation using donated blood samples, the sensitivity of the NAT system was checked by spiking experiments. Viral particles of pandemic (H1N1) 2009 virus (A/California/04/2009 [H1N1]), donated by the National Institute of Infectious Diseases, were spiked into plasma and erythrocyte samples from healthy volunteers. Viral RNA was detected in the plasma samples spiked with viral particles corresponding to 300 genome equivalents/mL and in the packed erythrocyte samples spiked with viral particles corresponding to 3,000 genome equivalents/mL. NAT was conducted by using 96 plasma and 67 erythrocyte samples obtained from 96 blood donors who had symptoms of influenza within 7 days postdonation. For 20 donors, pandemic (H1N1) 2009 was diagnosed within 1 day postdonation and, for another 20, within 2 days postdonation (Figure). Pandemic (H1N1) 2009 virus was not found in any of the samples tested, but it was consistently detected in the external positive control. These results suggest that the viremia with pandemic (H1N1) 2009 virus, if any, is very low and can be missed by current NAT or that the viremic period is too brief to identify viremia. Although the risk for transmission of pandemic influenza by transfusion seems to be low, further investigation is needed to elucidate this risk. Figure Number of blood donations from persons for whom pandemic (H1N1) 2009 infection was diagnosed postdonation and time between donation and diagnosis, by donor age, Japan.