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Hannolainen L, Pyöriä L, Pratas D, Lohi J, Skuja S, Rasa-Dzelzkaleja S, Murovska M, Hedman K, Jahnukainen T, Perdomo MF. Reactivation of a transplant recipient's inherited human herpesvirus 6 and implications to the graft. J Infect Dis 2024:jiae268. [PMID: 38768311 DOI: 10.1093/infdis/jiae268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 04/13/2024] [Indexed: 05/22/2024] Open
Abstract
BACKGROUND The implications of inherited chromosomally integrated human herpesvirus 6 (iciHHV-6) in solid organ transplantation remain uncertain. Although this trait has been linked to unfavorable clinical outcomes, an association between viral reactivation and complications has only been conclusively established in a few cases. In contrast to these studies, which followed donor-derived transmission, our investigation is the first to examine the pathogenicity of a recipient´s iciHHV-6B and its impact on the graft. METHODS We used hybrid capture sequencing for in-depth analysis of the viral sequences reconstructed from sequential liver biopsies. Moreover, we investigated viral replication through in situ hybridization (U38-U94 genes), real-time PCR (U89/U90 genes), immunohistochemistry, and immunofluorescence (against viral lysate). We also performed whole transcriptome sequencing of the liver biopsies to profile the host immune response. RESULTS We report a case of reactivation of a recipient´s iciHHV-6B and subsequent infection of the graft. Using a novel approach integrating the analysis of viral and mitochondrial DNAs, we located the iciHHV-6B intra-graft. We demonstrated active replication via the emergence of viral minor variants across time points, in addition to positive viral mRNAs and antigen stainings in tissue sections. Furthermore, we detected significant upregulation of cell surface molecules, transcription factors, and cytokines associated with antiviral immune responses, arguing against immunotolerance. CONCLUSIONS Our analysis underscores the potential pathological impact of iciHHV-6B, emphasizing the need for close monitoring of reactivation in transplant recipients. Most crucially, it highlights the critical role that the host's virome can play in shaping the outcome of transplantation, urging further investigations.
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Affiliation(s)
- Leo Hannolainen
- Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Lari Pyöriä
- Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Diogo Pratas
- Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Department of Electronics, Telecommunications and Informatics, University of Aveiro, Institute of Electronics and Informatics Engineering of Aveiro, University of Aveiro; Intelligent Systems Associate Laboratory, University of Aveiro, Aveiro, Portugal
| | - Jouko Lohi
- Department of Pathology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Sandra Skuja
- Joint Laboratory of Electron Microscopy, Institute of Anatomy and Anthropology, Rīga Stradiņš University, Riga, Latvia
| | | | - Modra Murovska
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Klaus Hedman
- Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Timo Jahnukainen
- Children's Hospital and Helsinki University Hospital, Department of Pediatric Nephrology and Transplantation, Helsinki, Finland
| | - Maria Fernanda Perdomo
- Department of Virology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Soffritti I, Gravelsina S, D'Accolti M, Bini F, Mazziga E, Vilmane A, Rasa-Dzelzkaleja S, Nora-Krukle Z, Krumina A, Murovska M, Caselli E. Circulating miRNAs Expression in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome. Int J Mol Sci 2023; 24:10582. [PMID: 37445763 DOI: 10.3390/ijms241310582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 06/15/2023] [Accepted: 06/21/2023] [Indexed: 07/15/2023] Open
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multifactorial disease that causes increasing morbidity worldwide, and many individuals with ME/CFS symptoms remain undiagnosed due to the lack of diagnostic biomarkers. Its etiology is still unknown, but increasing evidence supports a role of herpesviruses (including HHV-6A and HHV-6B) as potential triggers. Interestingly, the infection by these viruses has been reported to impact the expression of microRNAs (miRNAs), short non-coding RNA sequences which have been suggested to be epigenetic factors modulating ME/CFS pathogenic mechanisms. Notably, the presence of circulating miRNAs in plasma has raised the possibility to use them as valuable biomarkers for distinguishing ME/CFS patients from healthy controls. Thus, this study aimed at determining the role of eight miRNAs, which were selected for their previous association with ME/CFS, as potential circulating biomarkers of the disease. Their presence was quantitatively evaluated in plasma from 40 ME/CFS patients and 20 healthy controls by specific Taqman assays, and the results showed that six out of the eight of the selected miRNAs were differently expressed in patients compared to controls; more specifically, five miRNAs were significantly upregulated (miR-127-3p, miR-142-5p, miR-143-3p, miR-150-5p, and miR-448), and one was downmodulated (miR-140-5p). MiRNA levels directly correlated with disease severity, whereas no significant correlations were observed with the plasma levels of seven pro-inflammatory cytokines or with the presence/load of HHV-6A/6B genome, as judged by specific PCR amplification. The results may open the way for further validation of miRNAs as new potential biomarkers in ME/CFS and increase the knowledge of the complex pathways involved in the ME/CFS development.
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Affiliation(s)
- Irene Soffritti
- Department of Chemical, Pharmaceutical and Agricultural Sciences, and LTTA, University of Ferrara, 44121 Ferrara, Italy
| | - Sabine Gravelsina
- Institute of Microbiology and Virology, Rīga Stradiņš University, LV-1067 Riga, Latvia
| | - Maria D'Accolti
- Department of Chemical, Pharmaceutical and Agricultural Sciences, and LTTA, University of Ferrara, 44121 Ferrara, Italy
| | - Francesca Bini
- Department of Chemical, Pharmaceutical and Agricultural Sciences, and LTTA, University of Ferrara, 44121 Ferrara, Italy
| | - Eleonora Mazziga
- Department of Chemical, Pharmaceutical and Agricultural Sciences, and LTTA, University of Ferrara, 44121 Ferrara, Italy
| | - Anda Vilmane
- Institute of Microbiology and Virology, Rīga Stradiņš University, LV-1067 Riga, Latvia
| | | | - Zaiga Nora-Krukle
- Institute of Microbiology and Virology, Rīga Stradiņš University, LV-1067 Riga, Latvia
| | - Angelika Krumina
- Faculty of Medicine, Department of Infectology, Rīga Stradiņš University, LV-1006 Riga, Latvia
| | - Modra Murovska
- Institute of Microbiology and Virology, Rīga Stradiņš University, LV-1067 Riga, Latvia
| | - Elisabetta Caselli
- Department of Chemical, Pharmaceutical and Agricultural Sciences, and LTTA, University of Ferrara, 44121 Ferrara, Italy
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Rasa-Dzelzkaleja S, Krumina A, Capenko S, Nora-Krukle Z, Gravelsina S, Vilmane A, Ievina L, Shoenfeld Y, Murovska M. The persistent viral infections in the development and severity of myalgic encephalomyelitis/chronic fatigue syndrome. J Transl Med 2023; 21:33. [PMID: 36653846 PMCID: PMC9847171 DOI: 10.1186/s12967-023-03887-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/11/2023] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifactorial disease with an unexplained aetiology in which viral infections are possible trigger factors. The aim of this study was to determine the involvement of human herpesvirus (HHV)-6A/B, HHV-7, and parvovirus B19 (B19V) in the etiopathogenesis of ME/CFS. METHODS 200 patients with clinically diagnosed ME/CFS and 150 apparently healthy individuals were enrolled in this study. Single-round, nested, and quantitative real-time polymerase chain reactions (PCR) were used to detect the presence and load of HHV-6A/B, HHV-7, and B19V. HHV-6A and HHV-6B were distinguished by PCR and restriction analysis. Immunoenzymatic assays were applied to estimate the presence of virus-specific antibodies and the level of cytokines. RESULTS HHV-6A/B, HHV-7, and B19V specific antibodies were detected among patients and healthy individuals in 92.1% and 76.7%, 84.6% and 93.8%, and 78% and 67.4% of cases. HHV-6B had 99% of HHV-6 positive patients. Latent HHV-6A/B, HHV-7, and B19V infection/co-infection was observed in 51.5% of the patients and 76.7% of the healthy individuals, whereas active-45% of the ME/CFS patients and 8.7% of healthy individuals. HHV-6A/B load in patients with a persistent infection/co-infection in a latent and active phase was 262 and 653.2 copies/106 cells, whereas HHV-7 load was 166.5 and 248.5 copies/106 cells, and B19V-96.8 and 250.8 copies/106 cells, respectively. ME/CFS patients with persistent infection in an active phase had a higher level of pro-inflammatory cytokines (interleukin(IL)-6, tumor necrosis factor-alpha(TNF-α) and IL-12) and anti-inflammatory (IL-10) than with a persistent infection in a latent phase. A significant difference was revealed in the levels of TNF-α, IL-12, and IL-10 among the patient groups without infection, with latent infection/co-infection, active single, double and triple co-infection. The levels of TNF-α, IL-12, and IL-10 are significantly higher in patients with severe compared with a moderate course of ME/CFS. CONCLUSIONS Significantly more persistent HHV-6A/B, HHV-7, and B19V infection/co-infection in an active phase with a higher viral load and elevated levels of pro- and anti-inflammatory cytokines among patients with ME/CFS than healthy individuals indicate the importance of these infections/co-infections in ME/CFS development. The presence of these infections/co-infections influences the ME/CFS clinical course severity.
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Affiliation(s)
- Santa Rasa-Dzelzkaleja
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Angelika Krumina
- grid.17330.360000 0001 2173 9398Faculty of Medicine, Department of Infectology, Rīga Stradiņš University, Riga, Latvia
| | - Svetlana Capenko
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Zaiga Nora-Krukle
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Sabine Gravelsina
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Anda Vilmane
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Lauma Ievina
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Yehuda Shoenfeld
- grid.413795.d0000 0001 2107 2845Zabludowicz Center for Autoimmune Diseases, Sheba Medical Centre, Ramat Gan, Israel
| | - Modra Murovska
- grid.17330.360000 0001 2173 9398Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
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Gravelsina S, Vilmane A, Svirskis S, Rasa-Dzelzkaleja S, Nora-Krukle Z, Vecvagare K, Krumina A, Leineman I, Shoenfeld Y, Murovska M. Biomarkers in the diagnostic algorithm of myalgic encephalomyelitis/chronic fatigue syndrome. Front Immunol 2022; 13:928945. [PMID: 36300129 PMCID: PMC9589447 DOI: 10.3389/fimmu.2022.928945] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 09/21/2022] [Indexed: 12/02/2022] Open
Abstract
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex disease that is mainly diagnosed based on its clinical symptoms. Biomarkers that could facilitate the diagnosis of ME/CFS are not yet available; therefore, reliable and clinically useful disease indicators are of high importance. The aim of this work was to analyze the association between ME/CFS clinical course severity, presence of HHV-6A/B infection markers, and plasma levels of autoantibodies against adrenergic and muscarinic acetylcholine receptors. A total of 134 patients with ME/CFS and 33 healthy controls were analyzed for the presence of HHV-6A/B using PCRs, and antibodies against beta2-adrenergic receptors (β2AdR) and muscarinic acetylcholine receptors (M3 AChR and M4 AChR) using ELISAs. HHV-6A/B U3 genomic sequence in whole-blood DNA was detected in 19/31 patients with severe ME/CFS, in 18/73 moderate ME/CFS cases, and in 7/30 mild ME/CFS cases. Severity-related differences were found among those with a virus load of more than 1,000 copies/106 PBMCs. Although no disease severity-related differences in anti-β2AdR levels were observed in ME/CFS patients, the median concentration of these antibodies in plasma samples of ME/CFS patients was 1.4 ng/ml, while in healthy controls, it was 0.81 ng/ml, with a statistically significant increased level in those with ME/CFS (p = 0.0103). A significant difference of antibodies against M4 AChR median concentration was found between ME/CFS patients (8.15 ng/ml) and healthy controls (6.45 ng/ml) (p = 0.0250). The levels of anti-M4 plotted against disease severity did not show any difference; however, increased viral load correlates with the increase in anti-M4 level. ME/CFS patients with high HHV-6 load have a more severe course of the disease, thus confirming that the severity of the disease depends on the viral load—the course of the disease is more severe with a higher viral load. An increase in anti-M4 AchR and anti-β2AdR levels is detected in all ME/CFS patient groups in comparison to the control group not depending on ME/CFS clinical course severity. However, the increase in HHV-6 load correlates with the increase in anti-M4 level, and the increase in anti-M4 level, in turn, is associated with the increase in anti-β2AdR level. Elevated levels of antibodies against β2AdR and M4 receptors in ME/CFS patients support their usage as clinical biomarkers in the diagnostic algorithm of ME/CFS.
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Affiliation(s)
- Sabine Gravelsina
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
- *Correspondence: Sabine Gravelsina,
| | - Anda Vilmane
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Simons Svirskis
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | | | - Zaiga Nora-Krukle
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Katrine Vecvagare
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
| | - Angelika Krumina
- Department of Infectology, Rīga Stradiņš University, Riga, Latvia
| | - Iana Leineman
- Zabludowicz Center for Autoimmune Diseases, Sheba Medical Center, Affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Yehuda Shoenfeld
- Zabludowicz Center for Autoimmune Diseases, Sheba Medical Center, Affiliated with the Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv, Israel
| | - Modra Murovska
- Institute of Microbiology and Virology, Rīga Stradiņš University, Riga, Latvia
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5
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Vilmane A, Terentjeva A, Tamosiunas PL, Suna N, Suna I, Petraityte-Burneikiene R, Murovska M, Rasa-Dzelzkaleja S, Nora-Krukle Z. Human Parvoviruses May Affect the Development and Clinical Course of Meningitis and Meningoencephalitis. Brain Sci 2020; 10:brainsci10060339. [PMID: 32503112 PMCID: PMC7349785 DOI: 10.3390/brainsci10060339] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 05/29/2020] [Accepted: 06/01/2020] [Indexed: 12/18/2022] Open
Abstract
Meningitis and meningoencephalitis are neurological inflammatory diseases, and although routine diagnostics include testing of a wide range of pathogens, still in many cases, no causative agent is detected. Human parvovirus B19 (B19V), human bocaviruses 1–4 (HBoV1–4), and human parvovirus 4 (hPARV4) are members of the Parvoviridae family and are associated with a wide range of clinical manifestations including neurological disorders. The main aim of this study was to determine whether human parvoviruses infection markers are present among patients with meningitis/meningoencephalitis in Latvia as well as to clarify the role of these viruses on the clinical course of the mentioned diseases. Our study revealed HBoV1–4 and B19V genomic sequences in 52.38% and 16.67% of patients, respectively. Furthermore, symptoms such as the presence of a headache and its severity, fatigue, disorientation, and difficulties to concentrate were significantly frequently present in patients with active parvovirus infection in comparison with parvoviruses negative patients, therefore we suggest that HBoV1–4 and B19V infection should be included in the diagnostics to reduce the number of meningitis/meningoencephalitis with unknown/unexplained etiology.
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Affiliation(s)
- Anda Vilmane
- Institute of Microbiology and Virology, Rīga Stradiņš University, 5 Ratsupites St., LV-1067 Riga, Latvia; (A.T.); (M.M.); (S.R.-D.); (Z.N.-K.)
- Correspondence: ; Tel.: +371-67060838
| | - Anna Terentjeva
- Institute of Microbiology and Virology, Rīga Stradiņš University, 5 Ratsupites St., LV-1067 Riga, Latvia; (A.T.); (M.M.); (S.R.-D.); (Z.N.-K.)
| | - Paulius L. Tamosiunas
- Vilnius University Life Sciences Center Institute of Biotechnology, 7 Sauletekio Al., 10257 Vilnius, Lithuania; (P.L.T.); (R.P.-B.)
| | - Normunds Suna
- Department of Neurology and Neurosurgery, Riga East Clinical University Hospital “Gaiļezers”, 2 Hipokrata St., LV-1038 Riga, Latvia; (N.S.); (I.S.)
| | - Inga Suna
- Department of Neurology and Neurosurgery, Riga East Clinical University Hospital “Gaiļezers”, 2 Hipokrata St., LV-1038 Riga, Latvia; (N.S.); (I.S.)
| | - Rasa Petraityte-Burneikiene
- Vilnius University Life Sciences Center Institute of Biotechnology, 7 Sauletekio Al., 10257 Vilnius, Lithuania; (P.L.T.); (R.P.-B.)
| | - Modra Murovska
- Institute of Microbiology and Virology, Rīga Stradiņš University, 5 Ratsupites St., LV-1067 Riga, Latvia; (A.T.); (M.M.); (S.R.-D.); (Z.N.-K.)
| | - Santa Rasa-Dzelzkaleja
- Institute of Microbiology and Virology, Rīga Stradiņš University, 5 Ratsupites St., LV-1067 Riga, Latvia; (A.T.); (M.M.); (S.R.-D.); (Z.N.-K.)
| | - Zaiga Nora-Krukle
- Institute of Microbiology and Virology, Rīga Stradiņš University, 5 Ratsupites St., LV-1067 Riga, Latvia; (A.T.); (M.M.); (S.R.-D.); (Z.N.-K.)
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6
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Ziemele I, Xu M, Vilmane A, Rasa-Dzelzkaleja S, Hedman L, Hedman K, Söderlund-Venermo M, Nora-Krukle Z, Murovska M, Gardovska D. Acute human bocavirus 1 infection in child with life-threatening bilateral bronchiolitis and right-sided pneumonia: a case report. J Med Case Rep 2019; 13:290. [PMID: 31519214 PMCID: PMC6744643 DOI: 10.1186/s13256-019-2222-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 08/08/2019] [Indexed: 01/04/2023] Open
Abstract
Background Human bocavirus 1 is a commonly detected human parvovirus. Many studies have shown human bocavirus 1 as a pathogen in association with acute respiratory tract infections in children. However, because human bocavirus 1 persists in the upper airways for extensive time periods after acute infection, the definition and diagnostics of acute human bocavirus 1 infection is challenging. Until now, detection of human bocavirus 1 exclusively, high viral load in respiratory samples, and viremia have been associated with a clinical picture of acute respiratory illness. There are no studies showing detection of human bocavirus 1 messenger ribonucleic acid in the peripheral blood mononuclear cells as a diagnostic marker for acute lower respiratory tract infection. Case presentation We report the case of a 17-month-old Latvian boy who presented in intensive care unit with acute bilateral bronchiolitis, with a history of rhinorrhea and cough for 6 days and fever for the last 2 days prior to admission, followed by severe respiratory distress and tracheal intubation. Human bocavirus 1 was the only respiratory virus detected by a qualitative multiplex polymerase chain reaction panel. For the diagnosis of acute human bocavirus 1 infection, both molecular and serological approaches were used. Human bocavirus 1 deoxyribonucleic acid (DNA) was detected simultaneously in nasopharyngeal aspirate, stool, and blood, as well as in the corresponding cell-free blood plasma by qualitative and quantitative polymerase chain reaction, revealing high DNA-copy numbers in nasopharyngeal aspirate and stool. Despite a low-load viremia, human bocavirus 1 messenger ribonucleic acid was found in the peripheral blood mononuclear cells. For detection of human bocavirus 1-specific antibodies, non-competitive immunoglobulin M and competitive immunoglobulin G enzyme immunoassays were used. The plasma was positive for both human bocavirus 1-specific immunoglobulin M and immunoglobulin G antibodies. Conclusions The presence of human bocavirus 1 genomic DNA in blood plasma and human bocavirus 1 messenger ribonucleic acid in peripheral blood mononuclear cells together with human bocavirus 1-specific immunoglobulin M are markers of acute human bocavirus 1 infection that may cause life-threatening acute bronchiolitis.
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Affiliation(s)
- Inga Ziemele
- Children's Clinical University Hospital, Riga, Latvia. .,Department of Pediatrics Rīga Stradiņš University, Riga, Latvia.
| | - Man Xu
- Department of Virology, University of Helsinki, Helsinki, Finland
| | - Anda Vilmane
- Institute of Microbiology and Virology, Rīga Stradiņš University Riga, Riga, Latvia
| | | | - Lea Hedman
- Department of Virology, University of Helsinki, Helsinki, Finland.,Helsinki University Hospital Laboratory Service, Helsinki, Finland
| | - Klaus Hedman
- Department of Virology, University of Helsinki, Helsinki, Finland.,Helsinki University Hospital Laboratory Service, Helsinki, Finland
| | | | - Zaiga Nora-Krukle
- Institute of Microbiology and Virology, Rīga Stradiņš University Riga, Riga, Latvia
| | - Modra Murovska
- Institute of Microbiology and Virology, Rīga Stradiņš University Riga, Riga, Latvia
| | - Dace Gardovska
- Children's Clinical University Hospital, Riga, Latvia.,Department of Pediatrics Rīga Stradiņš University, Riga, Latvia
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