Preferential association of hepatitis C virus with CD19+ B cells is mediated by complement system

Extrahepatic disease manifestations are common in chronic hepatitis C virus (HCV) infection. The mechanism of HCV-related lymphoproliferative disorders is not fully understood. Recent studies have found that HCV in peripheral blood mononuclear cells (PBMCs) from chronically infected patients is mainly associated with CD19+ B cells. To further elucidate this preferential association of HCV with B cells, we used in vitro cultured virus and uninfected PBMCs from healthy blood donors to investigate the necessary serum components that activate the binding of HCV to B cells. First, we found that the active serum components were present not only in HCV carriers, but also in HCV recovered patients and HCV negative healthy blood donors and that the serum components were heat labile. Second, the preferential binding activity of HCV to B cells could be blocked by anti-complement C3 antibodies. In experiments with complement-depleted serum and purified complement proteins, we demonstrated that complement proteins C1, C2, and C3 were required to activate such binding activity. Complement protein C4 was partially involved in this process. Third, using antibodies against cell surface markers, we showed that the binding complex mainly involved CD21 (complement receptor 2), CD19, CD20, and CD81; CD35 (complement receptor 1) was involved but had lower binding activity. Fourth, both anti-CD21 and anti-CD35 antibodies could block the binding of patient-derived HCV to B cells. Fifth, complement also mediated HCV binding to Raji cells, a cultured B cell line derived from Burkitt´s lymphoma.CONCLUSION:In chronic HCV infection, the preferential association of HCV with B cells is mediated by the complement system, mainly through complement receptor 2 (CD21), in conjunction with the CD19 and CD81 complex. This article is protected by copyright. All rights reserved.Fil: Wang, Richard. National Institutes of Health; Estados UnidosFil: Baré, Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Medicina Experimental. Academia Nacional de Medicina de Buenos Aires. Instituto de Medicina Experimental; Argentina. National Institutes of Health; Estados UnidosFil: De Giorgi, Valeria. National Institutes of Health; Estados UnidosFil: Matsuura, Kentaro. Nagoya City University Graduate School of Medicine; Japón. National Institutes of Health; Estados UnidosFil: Salam, Kazi Abdus. National Institutes of Health; Estados Unidos. University of Rajshahi; IndiaFil: Grandinetti, Teresa. National Institutes of Health; Estados UnidosFil: Schechterly, Cathy. National Institutes of Health; Estados UnidosFil: Alter, Harvey J.. National Institutes of Health; Estados Unido

An assessment of hepatitis E virus (HEV) in US blood donors and recipients: No detectable HEV RNA in 1939 donors tested and no evidence for HEV transmission to 362 prospectively followed recipients.

BACKGROUND: Hepatitis E virus (HEV) infection has become relevant to blood transfusion practice because isolated cases of blood transmission have been reported and because HEV has been found to cause chronic infection and severe liver disease in immunocompromised patients. STUDY DESIGN AND METHODS: We tested for immunoglobulin (Ig)G and IgM antibodies to the HEV and for HEV RNA in 1939 unselected volunteer US blood donors. Subsequently, we tested the same variables in pre- and serial posttransfusion samples from 362 prospectively followed blood recipients to assess transfusion risk. RESULTS: IgG anti-HEV seroprevalence in the total 1939 donations was 18.8%: 916 of these donations were made in 2006 at which time the seroprevalence was 21.8% and the remaining 1023 donations were in 2012 when the seroprevalence had decreased to 16.0% (p \u3c 0.01). A significant (p \u3c 0.001) stepwise increase in anti-HEV seroprevalence was seen with increasing age. Eight of 1939 donations (0.4%) tested anti-HEV IgM positive; no donation was HEV RNA positive. Two recipients had an apparent anti-HEV seroconversion, but temporal relationships and linked donor testing showed that these were not transfusion-transmitted HEV infections. CONCLUSION: No transfusion-transmitted HEV infections were observed in 362 prospectively followed blood recipients despite an anti-HEV seroprevalence among donations exceeding 16%

Investigation of residual hepatitis C virus in presumed recovered subjects

Recent studies have found hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMCs) of the majority of presumed recovered subjects. We investigated this unexpected finding using samples from patients whose HCV RNA and anti-HCV status had been serially confirmed. HCV RNA was detected in PBMCs from 66/67 chronic HCV carriers. Subpopulation analysis revealed that the viral load (log copies/10(6) cells) in B cells (4.14 ± 0.71) was higher than in total PBMCs (3.62 ± 0.71, p<0.05), T cells (1.67 ± 0.88, p<0.05), and non-B/T cells (2.48 ± 1.15, p<0.05). HCV negative-strand RNA was not detected in PBMCs from any of 25 chronically infected patients. No residual viral RNA was detected in total PBMCs or plasma of 59 presumed recovered subjects (11 spontaneous, 48 treatment-induced) using nested real-time PCR with a detection limit of 2 copies/µg RNA (from ∼1x10(6) cells). PBMCs from two healthy HCV-negative blood donors became HCV RNA positive, with B-cell predominance, when mixed in vitro with HCV RNA positive plasma, thus passively mimicking cells from chronic HCV carriers. No residual HCV was detected in liver or other tissues from two spontaneously recovered chimpanzees. Conclusion: 1) HCV RNA was detected in PBMCs of most chronic HCV carriers and was predominant in the B cell subpopulation; 2) HCV detected in PBMCs was in a non-replicative form; 3) HCV passively adsorbed to PBMCs of healthy controls in vitro becoming indistinguishable from PBMCs of chronic HCV carriers; 4) Residual HCV was not detected in the plasma or PBMCs of any spontaneous or treatment recovered subjects or in chimpanzee liver suggesting that the classic pattern of recovery from HCV infection is generally equivalent to viral eradication.Fil: Fujiwara, Kei. National Institutes of Health; Estados UnidosFil: Allison, Robert. D.. National Institutes of Health; Estados Unidos. United States Navy; Estados UnidosFil: Wang, Richard Y.. National Institutes of Health; Estados UnidosFil: Baré, Patricia. National Institutes of Health; Estados Unidos. Academia Nacional de Medicina de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Matsuura, Kentaro. Nagoya City University; JapónFil: Schechterly, Cathy. National Institutes of Health; Estados UnidosFil: Murthy, Krishna.Fil: Marincola, Francesco M.. National Institutes of Health; Estados UnidosFil: Alter, Harvey J.. National Institutes of Health; Estados Unido

Absence of transfusion-associated microchimerism in pediatric and adult recipients of leukoreduced and gamma-irradiated blood components.

BACKGROUND: Transfusion-associated microchimerism (TA-MC), the persistence of significant levels of donor leukocytes in blood recipients for prolonged periods, has been demonstrated following non-leukoreduced and leukoreduced transfusion to patients with severe traumatic injury. Development of TA-MC has not been rigorously studied in settings that do not involve massive trauma where the blood is leukoreduced and irradiated. STUDY DESIGN AND METHODS: A cohort of 409 prospectively followed medical and surgical adult and pediatric female recipients of leukoreduced and mostly irradiated allogeneic red blood cell and platelet transfusions were evaluated to determine development of TA-MC. Four and eight-week post-transfusion samples were analyzed using quantitative real-time polymerase chain reaction (RT-PCR) for Y-chromosome sequences in leukocyte DNA, the marker for microchimeric cells in female blood recipients. Repeat testing was performed on Y-chromosome positive samples to confirm microchimerism (MC), and subsequent post-transfusion samples were tested to investigate persistence of MC. RESULTS: On initial testing, forty of 207 (19%) adult and forty-four of 202 (22%) pediatric female blood recipients demonstrated low level MC. On repeat testing of these and additional specimens, twelve (3%) recipients demonstrated low level transient MC, but none had persistent TA-MC similar to that seen in transfused trauma patients. CONCLUSION: Persistence of MC was not demonstrated in adult and pediatric recipients of leukoreduced and mostly irradiated blood components. The risk of TA-MC appears to be dependent on the clinical setting and is rare other than in patients sustaining severe traumatic injury

An assessment of hepatitis E virus (HEV) in US blood donors and recipients: no detectable HEV RNA in 1939 donors tested and no evidence for HEV transmission to 362 prospectively followed recipients

National Heart, Lung, and Blood Institute of the National Institutes of Health (NIH) [R01 HL67229]; NIH Clinical Center Intramural Program, TRIPS Protocol [01-CC-0231]BackgroundHepatitis E virus (HEV) infection has become relevant to blood transfusion practice because isolated cases of blood transmission have been reported and because HEV has been found to cause chronic infection and severe liver disease in immunocompromised patients. Study Design and MethodsWe tested for immunoglobulin (Ig)G and IgM antibodies to the HEV and for HEV RNA in 1939 unselected volunteer US blood donors. Subsequently, we tested the same variables in pre- and serial posttransfusion samples from 362 prospectively followed blood recipients to assess transfusion risk. ResultsIgG anti-HEV seroprevalence in the total 1939 donations was 18.8%: 916 of these donations were made in 2006 at which time the seroprevalence was 21.8% and the remaining 1023 donations were in 2012 when the seroprevalence had decreased to 16.0% (p<0.01). A significant (p<0.001) stepwise increase in anti-HEV seroprevalence was seen with increasing age. Eight of 1939 donations (0.4%) tested anti-HEV IgM positive; no donation was HEV RNA positive. Two recipients had an apparent anti-HEV seroconversion, but temporal relationships and linked donor testing showed that these were not transfusion-transmitted HEV infections. ConclusionNo transfusion-transmitted HEV infections were observed in 362 prospectively followed blood recipients despite an anti-HEV seroprevalence among donations exceeding 16%

Inherent transcriptional signatures of NK cells are associated with response to IFN\u391+rivabirin therapy in patients with Hepatitis C Virus

Background: Differences in the expression of Natural Killer cell receptors have been reported to reflect divergent clinical courses in patients with chronic infections or tumors. However, extensive molecular characterization at the transcriptional level to support this view is lacking. The aim of this work was to characterize baseline differences in purified NK cell transcriptional activity stratified by response to treatment with PEG-IFNa/RBV in patients chronically infected with HCV. Methods: To this end we here studied by flow cytometer and gene expression profile, phenotypic and transcriptional characteristics of purified NK cells in patients chronically infected with HCV genotype-1 virus who were subsequently treated with PEG-IFNa/RBV. Results were further correlated with divergent clinical response obtained after treatment. Results: The pre-treatment transcriptional patterns of purified NK cells from patients subsequently undergoing a sustained virologic response (SVR) clearly segregated from those of non-responder (NR) patients. A set of 476 transcripts, including molecules involved in RNA processing, ubiquitination pathways as well as HLA class II signalling were differently expressed among divergent patients. In addition, treatment outcome was associated with differences in surface expression of NKp30 and NKG2D. A complex relationship was observed that suggested for extensive post-transcriptional editing. Only a small number of the NK cell transcripts identified were correlated with chronic HCV infection/replication indicating that inherent transcriptional activity prevails over environment effects such as viral infection. Conclusions: Collectively, inherent/genetic modulation of NK cell transcription is involved in setting the path to divergent treatment outcomes and could become useful to therapeutic advantage