Human parvovirus B19 infection in bone marrow transplantation patients

Human parvovirus B19 in solid organ transplantation: Guidelines from the American society of transplantation infectious diseases community of practice

Clinical manifestations of human parvovirus B19 infection can vary widely and may be atypical in solid organ transplant (SOT) recipients. However, disease is apparent when there is destruction of erythrocyte progenitor cells leading to severe acute or chronic anemia with lack of an appropriate reticulocyte response in the setting of active parvovirus B19 infection. Serology may not reliably establish the diagnosis. High-level viremia is more likely to be associated with symptomatic disease. Conversely, ongoing DNAemia after infection may not be clinically significant, if detected at low levels. Despite lack of robust data, intravenous immunoglobulin (IVIG) is frequently used for the treatment of SOT recipients with symptomatic parvovirus B19 infection. Although the optimal dosage and duration of IVIG is not known, most patients receive a total of 2 g/kg over a period of 2-5 days. A daily dose of 1 g/kg or more seems to be associated with higher incidence of toxicity. Application of standard and droplet isolation precautions remains the cornerstone for preventing human parvovirus B19 transmission. Additional research is needed to assess the efficacy of current and novel therapies and to develop a safe and effective parvovirus B19 vaccine.

Modeling the parvovirus B19 blood safety risk in Australia

BACKGROUND

Three probable cases of transfusion-transmitted (TT) parvovirus B19 (B19V) occurred in Australia between 2014 and 2017. This study aimed to determine the B19V DNA prevalence among blood donors, to model the risk to recipients of fresh components, and to assess risk management options.

STUDY DESIGN AND METHODS

Plasma samples from 4232 donors were tested for B19V DNA by polymerase chain reaction. Reactive samples were confirmed and viral load determined. A transmission-risk model was used to estimate recipient risk, and the risk from community exposure was estimated using seroprevalence data.

RESULTS

Two samples (0.0473%, 95% confidence interval [CI] 0.0130-0.172) confirmed positive for B19V DNA had a potentially infectious viral load of 10⁵ IU/mL or higher. The estimated risk of a TT-B19V-associated significant complication was low overall at approximately 1 in 300,000 (95% CI, 1 in 82,000 to 1 in 1 million) fresh components transfused, with 3.1 (95% CI, 0.85-11.3) complications modeled per year. Among vulnerable recipient groups, the risk was higher than 1 in 15,000 patients, but the risk from community exposure far exceeded the transfusion risk for all patient and age groups.

CONCLUSION

In the context of the small contribution of transfusion to the burden of B19V disease, the significant costs that would be incurred by any strategy to reduce the risk, and given the significant uncertainties and likely overestimation of the risk, we conclude TT-B19V is a tolerable risk to blood safety, despite being high for some vulnerable recipient groups.

Photodynamic inactivation of mammalian viruses and bacteriophages

Photodynamic inactivation (PDI) has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i) summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii) discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

Intravenous immunoglobulin as rescue therapy for BK virus nephropathy

BKVN has emerged as an important cause of pediatric renal allograft nephropathy, with significant graft dysfunction in majority of the cases. Reduced immunosuppression and cidofovir therapy are the most commonly used therapeutic options for the treatment of BKVN in these patients. Recently, a preliminary study in adult renal allograft recipients with BKVN showed a therapeutic response to a combined approach of immunosuppression reduction and IVIg administration. A therapeutic benefit of IVIg without another concomitant treatment intervention has not been evaluated. We report stabilization of renal functions, histological resolution of BKVN and significant reduction in BK viremia in pediatric renal transplant with the use of IVIg, after an inadequate response to immunosuppression reduction and cidofovir therapy. In addition, we review the current literature on the use of cidofovir in pediatric renal transplant patients with BKVN and the potential of IVIg use in this condition.

Pure red cell aplasia due to parvovirus B19 infection transmitted probably through hematopoietic stem cell transplantation

Human parvovirus B19 is a very common infectious pathogen in humans. In healthy subjects, B19 infection is the cause of a self-limiting subclinical erythroid aplasia, followed by rash or arthralgia. In immunocompromised patients B19 can cause chronic anemia. This report presents the case of a 19-year-old male who developed severe anemia shortly after successful allogeneic hematopoietic stem cell transplantation. His marrow showed selective erythroid aplasia, and real-time polymerase chain reaction assay confirmed parvovirus B19 infection. Despite repeated high-dose immunoglobulin treatment, he remained anemic. His hematological status markedly improved after cessation of immunosuppression. Retrospective examination of the donor's blood suggests that hematopoietic stem cells could be the source of infection.

Dose-by-dose virological and hematological responses to intravenous immunoglobulin in an immunocompromised patient with persistent parvovirus B19 infection

A 42-year-old male with stage IV mantle cell lymphoma received chemotherapy and autologous peripheral blood stem cell transplantation. He developed pancytopaenia, and bone marrow examination indicated a parvovirus B19 (PVB 19)-induced red cell aplasia, confirmed by virological tests. Multiple doses of intravenous immunoglobulin (IVIG) were given over the following months, with blood samples being taken after each dose for quantitative PVB 19 DNA and hematological testing to assess the response. Each dose of IVIG produced a 1-3 log(10) drop in PVB 19 DNA levels. Eventually, after the fifth dose of IVIG, the PVB 19 DNA was reduced to <10 copies/ml serum, with a gradual improvement in his hematological parameters. This report demonstrates how close monitoring of the virological and hematological response to IVIG therapy for persistent PVB 19 infection in an immunocompromised patient can optimize the usage of this relatively expensive, and sometimes scarce intervention.

Clinical aspects of parvovirus B19 infection

Parvovirus B19 is a significant human pathogen that causes a wide spectrum of clinical complications ranging from mild, self-limiting erythema infectiosum in immunocompetent children to lethal cytopenias in immunocompromised patients and intrauterine foetal death in primary infected pregnant women. The infection may also be persistent and can mimic or trigger autoimmune inflammatory disorders. Another important clinical aspect to consider is the risk of infection through B19-contaminated blood products. Recent advances in diagnosis and pathogenesis, new insights in the cellular immune response and newly discovered genotypes of human parvoviruses form a platform for the development of modern therapeutic and prophylactic alternatives.

Serologic and molecular detection of human Parvovirus B19 infection

Following its identification by Yvonne Cossart in 1975, human Parvovirus B19 has been recognized as the causative agent of a wide range of diseases. In childhood, the most common disease is a typical exanthema called "fifth disease". In adults, viral infection may be responsible for fetal loss and for aplastic anaemia in immuno-compromised patients. Because persistent viral infection may induce an autoimmune response, Parvovirus B19 is emerging as an environmental factor linked to the pathogenesis of autoimmunity. As a result of its expanding disease spectrum, Parvovirus B19 is the subject of intense efforts to clarify the pathogenesis of virus-related disorders as well as improve diagnostic laboratory testing including standardization of serological and nucleic acid-based detection assays. Enzymatic immunoassays based on conformational antigens have proven to be the most important tools for accurate diagnosis in the majority of cases. In other selected clinical cases, the detection of Parvovirus B19 infection can be complemented by PCR and, more recently, by the real-time PCR.

Parvovirus B19 infection after transplantation: a review of 98 cases

BACKGROUND

Infections with parvovirus B19 (PVB19) can cause significant morbidity in transplant recipients.

METHODS

To characterize the epidemiology and clinical spectrum of posttransplant PVB19 infection, we reviewed all cases at our institution during a 16-year period, summarized the data from 91 cases published in the medical literature, and performed longitudinal molecular surveillance for PVB19 DNAemia among 47 solid organ and hematopoietic stem cell transplant recipients.

RESULTS

The median time to onset of PVB19 disease was 7 weeks after transplantation. Anemia, leukopenia, and thrombocytopenia were present in 98.8%, 37.5%, and 21.0% of patients, respectively. Hepatitis, myocarditis, and pneumonitis were also reported in association with PVB19 disease. Allograft tissue loss or dysfunction was observed at the time of PVB19 disease in 10% of cases. At the onset of disease, PVB19 IgM serological test results were negative in 29% of cases. Almost all patients (96%) with anti-PVB19 IgM had a positive PVB19 polymerase chain reaction assay result. Intravenous immunoglobulin was the most commonly used treatment modality. Three of 98 patients died of myocarditis and cardiogenic shock associated with PVB19 disease. Molecular surveillance throughout the first year after transplantation did not reveal PVB19 DNAemia in 47 anemic solid organ and hematopoietic stem cell transplant patients.

CONCLUSIONS

PVB19 is a rare but clinically significant infection that manifests as refractory anemia during the posttransplantation period. The use of polymerase chain reaction for diagnosis is particularly helpful in immunosuppressed transplant patients who may fail to mount antibodies against PVB19 during active infection.

Intravenous Immunoglobulin as a Treatment for BK Virus Associated Nephropathy: One-Year Follow-Up of Renal Allograft Recipients

BK virus associated nephropathy (BKVAN) has emerged as an important cause of renal allograft dysfunction and graft loss. Although several treatment strategies have been proposed, the rate of graft loss remains high. We studied the outcome of renal transplant patients with BKVAN treated with IVIG. After 11.4 +/- 3.9 months (mean +/- SEM) from the time of transplantation, 8 renal allograft recipients were diagnosed with BKVAN. In addition to a reduction of immunosuppressive therapy, patients received 2 g/kg IVIG. After a mean follow-up of 15 months, all except one patient are currently off dialysis. In summary, after IVIG therapy, 88% of patients still have functioning grafts, although renal function continues to be impaired. The benefit of concomitant IVIG and reduction of immunosuppressive therapy in BKVAN needs to be further addressed in randomized, multicentered trials.

Autologous peripheral blood progenitor cells are a potential source of parvovirus B19 infection

BACKGROUND

Parvovirus B19 is a cause of delayed red blood cell (RBC) engraftment after marrow transplantation (BMT). The diagnosis of parvovirus infection requires serologic and DNA testing in the context of clinical disease and characteristic marrow morphologic findings; however, the source of infection is often difficult to determine.

STUDY DESIGN AND METHODS

Investigation of a case of delayed RBC engraftment and pure RBC aplasia (PRCA) occurring 3 months after autologous peripheral blood progenitor cell (PBPC) transplantation in a patient with high-risk diffuse large B-cell lymphoma. DNA testing of serum and of a sample of cryopreserved PBPCs was performed.

RESULTS

Marrow morphology showed a maturational arrest of erythroid cells with giant proerythroblasts. Polymerase chain reaction and nucleic acid hybridization confirmed the presence of parvovirus DNA in the serum and in a sample of sequestered PBPCs saved at the time of PBPC harvest. PRCA resolved after the administration of intravenous immune globulin.

CONCLUSION

Autologous PBPCs are a potential source of parvovirus infection, which may cause significant disease after autologous BMT.

Pure red cell aplasia associated with parvovirus B19 infection occurring late after allogeneic bone marrow transplantation

Differential diagnosis for anemia late after allogeneic stem cell transplantation is broad. In this report, we describe a case of severe anemia secondary to pure red cell aplasia associated with human parvovirus B19 infection over 8 years after allogeneic bone marrow transplantation. Characteristics of parvovirus B19 infection and the immunosuppressed state after allogeneic stem cell transplantation are reviewed.

Human parvovirus B19

Parvovirus B19 (B19) was discovered in 1974 and is the only member of the family Parvoviridae known to be pathogenic in humans. Despite the inability to propagate the virus in cell cultures, much has been learned about the pathophysiology of this virus, including the identification of the cellular receptor (P antigen), and the control of the virus by the immune system. B19 is widespread, and manifestations of infection vary with the immunologic and hematologic status of the host. In healthy immunocompetent individuals B19 is the cause of erythema infectiosum and, particularly in adults, acute symmetric polyarthropathy. Due to the tropism of B19 to erythroid progenitor cells, infection in individuals with an underlying hemolytic disorder causes transient aplastic crisis. In the immunocompromised host persistent B19 infection is manifested as pure red cell aplasia and chronic anemia. Likewise, the immature immune response of the fetus may render it susceptible to infection, leading to fetal death in utero, hydrops fetalis, or development of congenital anemia. B19 has also been suggested as the causative agent in a variety of clinical syndromes, but given the common nature, causality is often difficult to infer. Diagnosis is primarily based on detection of specific antibodies by enzyme-linked immunosorbent assay or detection of viral DNA by dot blot hybridization or PCR. Treatment of persistent infection with immunoglobulin reduces the viral load and results in a marked resolution of anemia. Vaccine phase I trials show promising results.

Parvovirus B19 infection in pediatric solid-organ and bone marrow transplantation

The clinical significance of parvovirus B19 infection in pediatric solid-organ and bone marrow transplanted patients is unclear. The overall prevalence of parvovirus B19 infection in these patients is about 1-2% during the first year after transplantation. The most common symptom is anemia, but leukopenia and thrombocytopenia have also been observed. Rare cases of hepatic dysfunction, myocarditis, vasculitis and respiratory failure have also been reported. Whereas serology is of limited value around the time of transplantation, it is recommended that a search for B19 DNA is included in first-line investigations in any transplanted patient with unexplained anemia. Specific antiviral therapy is not available, however, intravenous immunoglobulin produces rapid improvement in most cases. Although relatively rare, the severe complications following parvovirus B19 infection in the transplant setting can be avoided by early diagnosis and treatment.

Association of parvovirus B19 with plasma cell-rich myocardial infiltrates after heart transplantation

In this report we describe the development of plasma cell-rich myocardial infiltrates in association with a parvovirus B19 infection in a heart transplant patient. We hypothesize that the virus, either alone or in association with the cardiac allograft, may polarize the immune response in the direction of T helper 2 (Th2) cells rather than the expected Th1 cells. This favors the development of a humoral immune response and infiltration of the graft with plasma cells.

Parvovirus B19 transmitted by bone marrow

We describe a case of symptomatic parvovirus B19 infection transmitted by bone marrow (BM). The infection caused prolonged anaemia, thrombocytopenia, arthralgia and erythema infectiosum in a 16-year-old girl with acute myeloid leukaemia receiving a BM transplant (BMT). The BM donor was a 19-year-old asymptomatic brother who had parvovirus B19 viraemia at the time of BM harvest. Sequencing of the VP2 gene from the patient and the donor showed a perfect match of DNA sequences, confirming the mode of transmission. Parvovirus B19 represents a potential complicating factor in patients undergoing BMT, but screening by polymerase chain reaction (PCR) of donor BM may reduce the risk of infection.

Pure red cell aplasia due to parvovirus B19 in a patient treated with rituximab

Rituximab is a chimeric monoclonal antibody directed against CD20 and used in the treatment of B-cell non-Hodgkin's lymphoma. Due to its ability to deplete B lymphocytes, rituximab can interfere with humoral immunity, causing it to be suppressed for several months after treatment. The reported case depicts a serious consequence of this effect of rituximab therapy: pure red cell aplasia resulting from chronic parvovirus B19 infection. The point of interest in this case is not only the association between rituximab therapy and pure red cell aplasia, but the diagnostic and therapeutic utility of the knowledge of parvovirus B19 as the likely etiologic link between the two. Given the known efficacy of intravenous immunoglobulin (IVIg) in the treatment of chronic parvovirus B19 infection, this therapy can cure some of these patients and successfully render most others transfusion-independent until recovery of their own humoral immune system.

Pure red cell aplasia due to parvovirus B19 in a patient treated with rituximab

Rituximab is a chimeric monoclonal antibody directed against CD20 and used in the treatment of B-cell non-Hodgkin's lymphoma. Due to its ability to deplete B lymphocytes, rituximab can interfere with humoral immunity, causing it to be suppressed for several months after treatment. The reported case depicts a serious consequence of this effect of rituximab therapy: pure red cell aplasia resulting from chronic parvovirus B19 infection. The point of interest in this case is not only the association between rituximab therapy and pure red cell aplasia, but the diagnostic and therapeutic utility of the knowledge of parvovirus B19 as the likely etiologic link between the two. Given the known efficacy of intravenous immunoglobulin (IVIg) in the treatment of chronic parvovirus B19 infection, this therapy can cure some of these patients and successfully render most others transfusion-independent until recovery of their own humoral immune system.

Infections in recipients of blood and marrow transplantation

The approach to infections in blood and marrow transplant (BMT) recipients involves an understanding of clinical infection syndromes and the natural history of individual infections, taken in the context of patterns of immunosuppression after transplantation and mechanisms underlying immune system reconstitution over time. The conditioning regimen used to prepare the host is a major determinant of host tissue injury and may lead to mucositis or diarrhea, facilitating transmucosal origin of bloodstream infections. Infectious risk also differs between autologous and allogeneic grafts as a consequence of ongoing immunosuppression from graft-versus-host disease and its therapy. Post-transplant complications may mimic infectious processes, and multiple infections may occur in one patient at the same time. Thus, the BMT patient with suspected infection should be evaluated in the context of pretransplant exposure history (infectious disease serologies), conditioning regimen, available culture data from nonsterile mucosal surfaces, previous and recent infections, contemporary transplant complications, and the current degree and duration of neutropenia, cellular immunodeficiency, and hypogammaglobulinemia.

Human parvovirus B19 infection in organ transplant recipients

We report a 61-yr-old kidney transplant recipient with human Parvovirus B19 (HPV B19) infection presenting as a severe pancytopenia 1 month after transplantation. Bone marrow aspiration revealed severe erythroid hypoplasia with giant and dystrophic proerythroblasts. Bone marrow cells were positive for HPV B19 DNA detected by polymerase chain reaction (PCR). Pancytopenia resolved shortly after administration of intravenous immunoglobulins. Nineteen cases of HPV B19 infection in organ transplant recipients have been so far reported in the literature. Immunocompromised patients should be considered at risk from developing symptomatic HPV B19 infections. In such patients, specific anti-HPV B19 IgM and IgG antibodies may be absent or transient and therefore their negativity cannot rule out the diagnosis of HPV B19 infestation. Bone marrow smear morphological findings may suggest the diagnosis but testing for viral DNA by PCR is mandatory. Patients may spontaneously recover. However, since specific anti-viral therapy is not currently available, intravenous immunoglobulin administration appears to be the more efficacious treatment.

Human parvovirus B19 infection associated with idiopathic thrombocytopenic purpura in a child following liver transplantation

BACKGROUND/AIMS

Idiopathic (autoimmune) thrombocytopenic purpura has been previously reported as a rare complication in children following parvovirus B19 infection. In the immunocompromised host who is unable to produce neutralizing antibody, an infection with parvovirus B19 can persist and cause chronic bone marrow failure.

METHODS

We describe a child who had undergone liver transplantation and who had idiopathic thrombocytopenic purpura, whose history and laboratory findings suggested parvovirus B19 infection. The infection disappeared without persistent viremia, and the thrombocytopenia responded completely to the administration of gamma globulin while the patient was undergoing chronic immunosuppression therapy.

RESULTS/CONCLUSION

Transplant physicians need to be aware of this complication, and parvovirus B19 infection should be included in the differential diagnosis of liver recipients presenting with severe thrombocytopenia.

Primary and secondary infections by human parvovirus B19 following bone marrow transplantation: characterization by PCR and B-cell molecular immunology

Due to the preparative regimen necessary, bone marrow transplantation (BMT) consistently results in severe immunodeficiency, often associated with anaemia, leukopenia and thrombocytopenia. Parvovirus B19 replicates in red blood cell precursors in the bone marrow and causes erythema infectiosum ('fifth disease'), anaemia, arthritis and foetal death. We assessed the significance of B19 infections as a cause of post-BMT complications. Over 900 serial serum samples from 201 allogeneic bone marrow recipients were studied by polymerase chain reaction (PCR) and by modern serodiagnostic methods. During the first 6 months after transplantation all BMT recipients remained B19 PCR-negative. Antibody screening for B19 infections was performed up to 36 months post-transplantation. Three cases of acute B19 infection were diagnosed during the second year post-BMT. To characterize the adoptively transferred immune system we measured subclasses and avidity of anti-VP1 IgG and epitope-type specificity (ETS) of anti-VP2 IgG, which allowed functional differentiation of primary and secondary B-cell responses long after BMT. The profile of the immune response was that of a primary infection in 1 and of reinfection in 2 of the 3 acute cases. Both types were clinically mild. Infection by human parvovirus B19 is not a frequent cause of post-BMT cytopenias. The findings with the new B19 antibody markers support the concept that the donated marrow determines the type of antiviral B-cell responses.

Parvovirus: the expanding spectrum of disease

Treatment of parvovirus infections among immunocompromised hosts using immunoglobulin has provided the clinician with a useful therapeutic tool but has also highlighted the problems concerning chronic disease states. The discovery of the human parvovirus B19 in 1975 and subsequent studies of its effects in humans have identified this virus as the causative agent of a broad spectrum of diseases. Recent improvements regarding the development of sensitive PCR techniques and methods for cultivation have provided new insight into its pathogenic role, its virology and immunology, and the varied clinical manifestations. The current state of knowledge concerning parvovirus enabled us to divide the long list of diseases caused by this virus into three main categories: (1) disease found among normal hosts (asymptomatic disease, erythema infectiosum, arthropathy, hydrops fetalis), (2) hematologic diseases (aplastic crisis, chronic anemia, idiopathic thrombocytopenic purpura, transient erythroblastopenia of childhood, Diamond-Blackfan anemia) and, finally, (3) a heterogeneous group of diseases, in which the etiologic role of parvovirus is less clear and sometimes putative (neurologic disease, rheumatologic disease, vasculitic and myocarditic syndromes). In particular, arthropathy, hydrops fetalis and the hematologic disorders may be of pediatric concern. Consequently, it is of paramount importance that in all of these cases the clinician includes parvovirus as a differential diagnosis.