Detection of hepatitis b virus DNA in the blood of a stem cell donor after granulocyte colony‐stimulating factor treatment

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Occult hepatitis B virus (HBV) infections have gained much attention in terms of transmissibility and reactivation.1 Here, we report the case of a healthy stem cell donor with serological evidence of a resolved HBV infection who became temporarily HBV DNA–positive in the blood after stimulation with granulocyte colony-stimulating factor (G-CSF). A 51-year-old man from the German Bone Marrow Donor Center was identified as human leukocyte antigen matching (10/10) stem cell donor for a 44-year-old female patient diagnosed with precursor B-cell acute lymphoblastic leukemia in the United Kingdom. This donor was a well-known blood donor since 2009 and was previously tested positive for antibody to hepatitis B core antigen, antibody to hepatitis B e antigen, and antibody to hepatitis B surface antigen (anti-HBs). During the diagnostic workup the serological findings could be confirmed and HBV DNA was not detected. Thus, in accordance with German regulations, this donor was considered eligible for stem cell donation. The donor started G-CSF treatment, and at day 5 cluster of differentiation 34 (CD34)–positive stem and progenitor cells were collected. At this time HBV DNA (pooled tested, detection limit 257 IU/mL) tested negative. The product was shipped from the German apheresis center to the UK transplantation center and infused after myeloablative conditioning of the patient had been completed. Six days after transplantation, testing of the product at the transplantation center revealed the presence of 26 IU/mL HBV DNA, which could be confirmed by testing backup samples (product and blood) (Table 1; Supporting Information). Therefore, the stem cell recipient immediately started lamivudine treatment and has tested negative for HBV DNA (last test day +130) ever since. Anti-HBs of the recipient was negative before transplantation but temporarily positive after transplantation (Supporting Information). (−7 days) Serum (+16 days) Serum HBV DNA testing of the donor was again negative at day 16 after apheresis. Anti-HBs titration and neutralizing experiments using hepatitis B surface antigen (HBsAg) from different genotypes specified the presence 3,300 IU/L anti-HBs in the blood of the donor highly capable of neutralizing HBsAg from different genotypes. Parts of the HBV DNA detected in the product could be amplified and genotyped, which was classified as genotype D and carried specific mutations. Two mutations (S204N/S207N) were located at the C terminus and one (T140S) in the a-determinant of HBsAg, which has been associated with immune escape rendering anti-HBs ineffective.2 This is the first case of a stem cell donor who became temporarily positive for HBV DNA following treatment with G-CSF. Because G-CSF treatment induces proliferation of hepatocytes or hepatic progenitor cells in humans and other animals, it is tempting to speculate that here the G-CSF treatment resulted in the proliferation of hepatocytes harboring HBV covalently closed circular DNA.3 However, further studies are needed to link HBV reactivation and cell proliferation and to address a potential role of CD34+ cells for the detectability of HBV DNA.4 In accordance with previous observations, the presence of anti-HBs did not always provide protection from HBV reactivation.5 At least in this case the presence of HBsAg mutations might have also contributed to the noneffectiveness of anti-HBs. At the moment it cannot be excluded that the G-CSF treatment coincided with the detection of HBV DNA in the blood and did not cause it. However, because the donor regularly gave blood from 2009 to 2014 without evidence of transmitting HBV and the HBV DNA levels immediately fell below the detection limit after the cessation of G-CSF therapy, it might be possible that the G-CSF treatment was responsible for the transient detectability of low levels of HBV DNA, which could not be detected by the pooled analysis of samples. It remains unclear whether infectious particles were circulating in the blood of the donor at the time of cell collection. The immediate antiviral treatment of the recipient prevented any comments on the infectivity of the CD34-positive cell product. Therefore, more studies are needed to explore the impact of G-CSF treatment on occult HBV infections and the potential risk of transmitting HBV through cell products. Especially, the screening of blood and cell products after G-CSF treatment using highly sensitive polymerase chain reaction protocols could give further insight into the frequency of HBV DNA positivity and would also help to identify samples which could be used for scrutinizing HBV infectivity. Additional Supporting Information may be found at onlinelibrary.wiley.com/doi/10.1002/hep.28667/suppinfo. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

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