Persistent human parvovirus B19 infection following an acute infection with meningitis in an immunocompetent patient

Ensuring Transfusion Safety: Screening Blood Donors for Human Parvovirus B19

Ensuring the safety of blood and blood products is a vital aspect of healthcare. The potential for transmission of pathogens through blood and blood products makes transfusion safety a significant concern. Despite advancements in testing methodologies, donated blood products still pose a risk for infection transmission. Human parvovirus B19 (B19V) is a small, single-stranded, non-enveloped DNA virus transmissible parenterally by blood transfusion. B19V causes a wide range of clinical manifestations, which is generally harmless in healthy individuals. B19V infection may cause severe complications, such as aplastic crises, as it affects erythrocyte progenitor cells in individuals with increased erythrocyte turnover. Additionally, B19V can be transmitted from pregnant women to their foetus, potentially causing hydrops fetalis and foetal death. The potential for transmission through blood and blood products makes B19V a significant concern for transfusion safety. In response to the growing recognition of B19V's impact on transfusion safety, various international health organisations have introduced guidelines to minimise its transmission through blood and plasma products. However, the implementation of these guidelines varies globally, with some regions, such as India, still lacking formal protocols for B19V monitoring. This review article explores the existing methodologies for screening blood donors for B19V, assesses the associated transfusion risks, and considers the implications for public health and clinical practice. By emphasising advancements in diagnostic techniques and the challenges of their implementation, this article provides a comprehensive overview of efforts to reduce the transmission of B19V through blood transfusions, thereby ensuring safer blood supplies and improved patient outcomes.

First report on severe septic shock associated with human Parvovirus B19 infection after cardiac surgery

Background

Human Parvovirus B19 (PB19) is a single-stranded DNA virus. Septic shock from viremia is rare with PB19; however, this infection can progress to life-threatening conditions. We report the first case of severe septic shock associated with a PB19 infection after cardiac surgery.

Case Presentation

A 50-year-old Chinese woman received elective double metal valve replacement, including the aortic valve and the mitral valve, under cardiopulmonary bypass (CPB) and suffered severe septic shock on postoperative day (PD) 30. Through the detection of PB19-specific nucleic acids in blister fluid and serum samples via metagenomic next-generation sequencing (mNGS), positive serum PB19 IgM and no other proven infection, acute PB19 infection was confirmed. After five days of combined treatment, no further fever or abdominal discomfort was noted, and the patient’s circulation gradually became stable without vasoactive medications.

Conclusion

PB19 may be an unrecognized cause of septic shock, rash, fever of unknown origin or multiple systemic signs and symptoms, especially in immunosuppressed and immunocompetent critically ill patients. Investigations for viral aetiology are needed.

Identification and Genomic Characterization of Parvovirus B19V Genotype 3 Viruses from Cases of Meningoencephalitis in West Bengal, India

Brain infections are a major public health problem in India and other parts of the world, causing both mortality and lifelong disability. Even after a thorough investigation, many cases remain without an etiological diagnosis. Primate erythroparvovirus 1 (B19V) has been identified as a pathogen associated with undiagnosed meningoencephalitis in other settings, including the United Kingdom, France, and Latvia. Here, we reported 13/403 (3.2%) B19V PCR positive cases of meningoencephalitis in West Bengal, India. The positive samples were mostly from children (10/13, 76.92%) and presented as a spectrum consisting of acute encephalitis (7/13), acute meningoencephalitis (3/13), and meningitis (3/13). Of the 13 cases, 8/13 (61.5%) had no known etiology and 5/13 (38.5%) had a previous etiological diagnosis. The cases did not cluster in time or by location, suggesting sporadic occurrence rather than outbreaks. We were able to retrieve the complete B19V genomes from cerebrospinal fluid (CSF) in 12/13 cases. The sequences clustered into genotype 3b with complete genomes from Brazil, Ghana, and France, and partial genomes from India and Kyrgyzstan. This is the first report of B19V in cases of neurological infections from India. It highlights the need to evaluate the causal relationship between B19V with meningoencephalitis in the country. These were also the first complete genomes of genotype 3b from CSF and will be critical in the evaluation of the relationship between genotypes and disease. IMPORTANCE Cases of meningoencephalitis with no known etiology remain a major challenge to clinical management of brain infections across the world. In this study, we detected and characterized the whole-genome of primate erythroparvovirus 1 (B19V) in cases of meningoencephalitis in India. Our work highlighted the association between B19V and brain infections which has been reported in other countries. Our work also emphasized the need to examine the role of B19V in meningoencephalitis, specifically whether it caused or contributed to the disease together with other pathogens in India. Our study provided the first 12 genomes of B19V from cerebrospinal fluid. These genomes will contribute to an understanding of how the virus is changing across different locations and over time.

Foscarnet Therapy for Pure Red Cell Aplasia Related to Human Parvovirus B19 Infection in Kidney Transplant Recipients: A Preliminary Exploration

Background

Parvovirus B19-associated pure red cell aplasia (PVB19-PRCA) is an uncommon but serious complication after kidney transplantation. Currently, intravenous immunoglobulin (IVIG) is preferred as the first-line treatment for PVB19-PRCA, but presents with disadvantages of disease recurrence and expensive cost. In this context, we propose that foscarnet therapy for kidney transplantation recipients (KTR) with PVB19-PRCA may be an alternative scenario. No related study has been reported, and we performed this study to assess the efficacy and safety of foscarnet for PVB19-associated PRCA in KTR.

Methods

We conducted a retrospective review of PVB19-PRCA in KTR at our center over 9-year period. The data on therapy and outcomes in all cases treated with foscarnet are detailed records and summarized.

Results

Among our 68 patients, PVB19-PRCA was confirmed in 50 based on inclusion/exclusion criteria. All patients presented with refractory anemia and low reticulocyte percentage (<0.5%), the mean hemoglobin of patients was 79.8±12.6g/L at the time of PVB19-PRCA was identified. The median serum genome copy number of parvovirus B19 at diagnosis was 9.6 log₁₀ copies per milliliter. A total of 11 patients received foscarnet therapy, of 10 patients responded well to the treatment and maintained no recurrence. But 1 patient had a poor response to foscarnet therapy. Except for this patient, the mean hemoglobin level gradually increased from 68.5±9.3 g/L to 73.2±8.8 g/L, and the mean percentage of reticulocytes steadily increased from 0.1±0.0% to 7.6±2.9% after foscarnet therapy. The median serum genome copy number of parvovirus B19 decreased from 9.8 log₁₀ to 6.1 log₁₀ copies per milliliter. There was no significant difference (P=0.61, 0.60) in serum creatinine and glomerular filtration rate before and after foscarnet treatment. At the latest follow-up, the mean hemoglobin was 131.5±12.5 g/L and the hemoglobin correction occurred in all patients.

Conclusion

Foscarnet therapy doesn't seem to be worse than IVIG for PVB19-PRCA in KTR, and it can be an alternative option.

Human Parvoviruses May Affect the Development and Clinical Course of Meningitis and Meningoencephalitis

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.

Human Parvoviruses

Parvovirus B19 (B19V) and human bocavirus 1 (HBoV1), members of the large Parvoviridae family, are human pathogens responsible for a variety of diseases. For B19V in particular, host features determine disease manifestations. These viruses are prevalent worldwide and are culturable in vitro, and serological and molecular assays are available but require careful interpretation of results. Additional human parvoviruses, including HBoV2 to -4, human parvovirus 4 (PARV4), and human bufavirus (BuV) are also reviewed. The full spectrum of parvovirus disease in humans has yet to be established. Candidate recombinant B19V vaccines have been developed but may not be commercially feasible. We review relevant features of the molecular and cellular biology of these viruses, and the human immune response that they elicit, which have allowed a deep understanding of pathophysiology.

Parvovirus B19

Primary parvovirus B19 infection is an infrequent, but serious and treatable, cause of chronic anemia in immunocompromised hosts. Many compromised hosts have preexisting antibody to B19 and are not at risk. However, upon primary infection, some patients may be able to mount a sufficient immune response to terminate active parvovirus B19 infection of erythroid precursors. The most common consequence of B19 infection in the compromised host is pure red-cell aplasia, resulting in chronic or recurrent anemia with reticulocytopenia. Anemia persists until neutralizing antibody is either produced by the host or passively administered. Parvovirus B19 should be suspected in compromised hosts with unexplained or severe anemia and reticulocytopenia, or when bone-marrow examination shows either giant pronormoblasts or absence of red-cell precursors. Diagnosis is established by detection of B19 DNA in serum in the absence of IgG antibody to B19. In some cases, IgG antibody is detected but is not neutralizing. Anti-B19 IgM may or may not be present. Therapy includes any or all of the following: red-cell transfusion, adjustment in medications to restore or improve the patient’s immune system, and administration of intravenous immunoglobulin (IVIG). Following treatment, patients should be closely monitored, especially if immunosuppression is unchanged or increased. Should hematocrit trend downward and parvovirus DNA trend upward, the therapeutic options above should be revisited. In a few instances, monthly maintenance IVIG may be indicated. Caregivers should be aware that B19 variants, though rarely encountered, can be missed or under-quantitated by some real-time polymerase-chain reaction methods.

Focal epilepsy as a long term sequela of Parvovirus B19 encephalitis

Human Parvovirus B19 (PVB19), the etiological agent of the fifth disease, is associated with a large spectrum of pathologies, among which is encephalitis. Since it has been detected from the central nervous system in children or in immunocompromised patients, its causative role in serious neurological manifestations is still unclear. Here we report the case of an 18-year-old healthy boy who developed encephalitis complicated by prolonged status epilepticus. The detection of PVB19 DNA in his serum and, subsequently, in his cerebrospinal fluid supports the hypothesis that this virus could potentially play a role in the pathogenesis of neurological complications. In addition, the detection of viral DNA and the presence of specific IgM and IgG antibodies in serum, together with clinical findings such as skin rash, support the presence of a disseminated viral infection. In the presence of neurological disorders, especially when there are no specific signs, but seizures and rash are present, it is important to search for PVB19 both in immunocompromised and immunocompetent patients. Moreover, the introduction of the PVB19 DNA test into diagnostic protocols of neuropathies, especially those undiagnosed, could clarify the etiological agent that otherwise could remain unrecognized.

Update of the human parvovirus B19 biology

Since its discovery, the human parvovirus B19 (B19V) has been associated with many clinical situations in addition to the prototype clinical manifestations, i.e. erythema infectiosum and erythroblastopenia crisis. The clinical significance of the viral B19V DNA persistence in sera after acute infection remains largely unknown. Such data may constitute a new clinical entity and is discussed in this manuscript. In 2002, despite the genetic diversity among B19V viruses has been reported to be very low, the description of markedly distinct sequences showed a new organization into three genotypes. The most recent common ancestor for B19V genotypes was estimated at early 1800s. B19V replication is enhanced by hypoxia and this might to explain the high viral load detected by quantitative PCR in the sera of infected patients. The minimum infectious dose necessary to transmit B19V infection by the transfusion of labile blood products remains unclear. At the opposite, the US Food and Drug Administration proposed a limit of 10(4)IU/mL of viral DNA in plasma pools used for the production of plasma derivatives. Recently, a new human parvovirus (PARV4) has been discovered. The consequences on blood transfusion of this blood-borne agent and its pathogenicity are still unknown.

Neurological aspects of human parvovirus B19 infection: a systematic review

Parvovirus B19 has been linked with various clinical syndromes including neurological manifestations. However, its role in the latter remains not completely understood. Although the last 10 years witnessed a surge of case reports on B19-associated neurological aspects, the literature data remains scattered and heterogeneous, and epidemiological information on the incidence of B19-associated neurological aspects cannot be accurately extrapolated. The aim of this review is to identify the characteristics of cases of B19-associated neurological manifestations. A computerized systematic review of existing literature concerning cases of B19-related neurological aspects revealed 89 articles describing 129 patients; 79 (61.2%) were associated with CNS manifestations, 41 (31.8%) were associated with peripheral nervous system manifestations, and 9 (7.0%) were linked with myalgic encephalomyelitis. The majority of the cases (50/129) had encephalitis. Clinical characteristic features of these cases were analyzed, and possible pathological mechanisms were also described. In conclusion, B19 should be included in differential diagnosis of encephalitic syndromes of unknown etiology in all age groups. Diagnosis should rely on investigation of anti-B19 IgM antibodies and detection of B19 DNA in serum or CSF. Treatment of severe cases might benefit from a combined regime of intravenous immunoglobulins and steroids. To confirm these outcomes, goal-targeted studies are recommended to exactly identify epidemiological scenarios and explore potential pathogenic mechanisms of these complications. Performing retrospective and prospective and multicenter studies concerning B19 and neurological aspects in general, and B19 and encephalitic syndromes in particular, are required. © 2014 The Authors. Reviews in Medical Virology published by John Wiley & Sons, Ltd.

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.

Aberrant cellular immune responses in humans infected persistently with parvovirus B19

A subset of parvovirus B19 (B19) infected patients retains the infection for years, as defined by detection of B19 DNA in bone marrow. Thus far, analysis of B19-specific humoral immune responses and viral genome variations has not revealed a mechanism for the absent viral clearance. In this study, ex-vivo cellular immune responses were assessed by enzyme linked immunospot assay mounted against the majority of the translated viral genome. Compared to seropositive healthy individuals, individuals with B19 persistence (2-8 years) showed larger number of responses to the structural proteins (P = 0.0022), whereas responses to the non-structural protein were of lower magnitude (P = 0.012). These observations provide the first findings of immunological discrepancies between individuals with B19 persistence and healthy individuals, findings that may reflect both failed immunity and antigenic exhaustion.

Neurological manifestations of human parvovirus B19 infection

Since its discovery, human parvovirus B19 has been linked with a broad spectrum of clinical syndromes. An aetiological role for the virus has been confirmed in erythema infectiosum, transient aplastic crisis, persistent infection manifesting as pure red cell aplasia in immunocompromised persons, non-immune hydrops fetalis and arthritis. Less commonly recognised, but receiving increasing attention recently, are the neurological manifestations, a variety of which have been described in patients with either clinically diagnosed or laboratory confirmed B19 infection. The purpose of this review is to summarise present knowledge of B19, its known and potential pathogenic mechanisms and its association with human diseases, particularly those with neurological manifestations. The outcome of the review supports an aetiological role of the virus in neurological disease. However, the pathogenesis remains unknown and elucidating this is a priority.

Molecular analysis of cerebrospinal fluid in viral diseases of the central nervous system

The use of nucleic acid (NA) amplification techniques has transformed the diagnosis of viral infections of the central nervous system (CNS). Because of their enhanced sensitivity, these methods enable detection of even low amounts of viral genomes in cerebrospinal fluid. Following more than 10 years of experience, the polymerase chain reaction or other NA-based amplification techniques are nowadays performed in most diagnostic laboratories and have become the test of choice for the diagnosis of several viral CNS infections, such as herpes encephalitis, enterovirus meningitis and other viral infections occurring in human immunodeficiency virus-infected persons. Furthermore, they have been useful to establish a viral etiology in neurological syndromes of dubious origin and to recognise unusual or poorly characterised CNS diseases. Quantitative methods have provided a valuable additional tool for clinical management of these diseases, whereas post-amplification techniques have enabled precise genome characterisation. Current efforts are aiming at further improvement of the diagnostic efficiency of molecular techniques, their speed and standardisation, and to reduce the costs. The most relevant NA amplification strategies and clinical applications of to date will be the object of this review.

Case report of meningoencephalitis during a concomitant mumps and parvovirus B19 infection

A 19-year-old, immunologically healthy man suffered from prolonged and intermittent high fever, left parotitis, systemic lymph node swelling, progressive liver dysfunction and leukocytopenia. 11 days after the fever onset, consciousness disturbance and generalized convulsion occurred. By the administration of gamma-globulin and steroid, the patient recovered completely. Serum titers of IgG and IgM specific for both human parvovirus B19 and mumps were elevated, and parvovirus B19 DNA was identified in the serum. It was speculated that overlap infection of mumps and parvovirus B19 made the disease more severe in this patient.

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.

Antibody responses in parvovirus B19 infected patients

Parvovirus B19 is the causative agent of erythema infectiosum. In addition, the infection may be associated with other disease manifestations: anemia and aplastic crisis, thrombo- or granulocytopenies; spontaneous abortion or hydrops fetalis in pregnant women; acute and chronic arthritis in adults and children, myocarditis and hepatitis. Both acute and persistent courses of B19-infections have been reported. All patients develop IgG against the capsid proteins VP1 and VP2, the majority of virus neutralizing antibodies that offer life-long protection against reinfections are directed against the VP1-unique region. IgM is mainly directed against VP2-specific epitopes. These antibodies may be present for only a rather short period of two to ten weeks after acute infection. IgG-antibodies against the nonstructural protein NS1 are preferentially found in patients which are unable to eliminate the virus and develop persisting viremia or virus persistence in distinct organs, e.g. synovial fluid, liver, bone marrow.

Screening of patients with complex regional pain syndrome for antecedent infections

OBJECTIVE

This study was designed to investigate whether Complex Regional Pain Syndrome type I (CRPS I) could be linked to any previous infection.

PATIENTS

Fifty-two patients with CRPS I of one extremity were screened for the presence of antibodies against mostly neurotropic microorganisms.

RESULTS

Of these 52 patients, none had antibodies against Treponema pallidum, Borrelia burgdorferi, or HTLV-1. Only four patients were positive for Campylobacter jejuni. For cytomegalovirus, Epstein-Barr virus, herpes simplex virus, and Toxoplasma gondii, seroprevalences were similar to control values. The total seroprevalence of Parvovirus B 19 in our CRPS population was 77%, which was significantly higher than in an independent Dutch population group (59%). Seroprevalence in lower extremity CRPS 1 (94%) was significantly higher than in upper extremity CRPS I patients (68%). In this study all patients were seropositive for varicella zoster virus (VZV) antibodies, but a high prevalence of VZV antibodies is similar to its prevalence in a normal population (>90%).

CONCLUSIONS

In this study we found a significantly higher seroprevalence of Parvovirus B19 in CRPS I and this is most striking in lower extremity CRPS I patients. Further serologic research in other geographic areas is needed to provide additional information about a potential role of Parvovirus B 19 or other microorganisms in the etiopathogenesis of CRPS I.

Parvovirus B19 causing leucopenia and neutropenia in a healthy adult

A 27-year-old healthy female presented with a prolonged and intermittent febrile illness. She was found to have leucopenia, neutropenia and thrombocytopenia, but a normal haemoglobin. The patient recovered spontaneously and convalescent serology 1 month later was positive for specific parvovirus B19 IgM and IgG. Parvovirus B19 infection was confirmed by detection of viral DNA by dot blot hybridization in a specimen of blood taken during the acute illness. A review of the previously reported cases of parvovirus B19-induced leucopenia in normal adults is presented. Parvovirus B19 should be considered in the differential diagnosis of leucopenia and neutropenia in healthy adults.

Seroprevalence of parvovirus B19 NS1-specific IgG in B19-infected and uninfected individuals and in infected pregnant women

Parvovirus B19 is the causative agent of erythema infectiosum in children, but the virus is associated with an increasing range of different diseases. These include acute and chronic arthritis, hydrops fetalis in pregnant women, aplastic anemia, and thrombocytopenia. The host's immune response is directed against the viral structural proteins VP1 and VP2. This study investigated the presence of IgG against the viral nonstructural protein NS1 using Western blot. Serum panels from healthy individuals, B19-infected pregnant women, and various disease groups were tested. The disease groups included patients with symptoms that may be linked to parvovirus B19 infection. The results showed that IgG against the NS1 protein was present in 22% of healthy individuals with past B19 infection. In cases of persistent or prolonged B19 infections, the prevalence of NS1-specific antibodies was as high as 80%. It is concluded that NS1-specific IgG may be used as an indicator of chronic or more severe courses of parvovirus B19 infections.

Acute parvovirus B19 infection in connection with a flare of systemic lupus erythematodes in a female patient

BACKGROUND

Since its discovery parvovirus B19-infections could be linked to a growing variety of diseases. Besides the harmless exanthema erythema infectiosum perferentially observed with B19-infections in childhood a panel of rather serious and also chronic courses that may be associated with anemia, thrombocytopenia, arthritis and others have been described.

OBJECTIVE

In a 26-year-old female patient an acute parvovirus B19-infection was followed by a serious episode of systemic lupus erythematosus (SLE). Here we demonstrate the clinical and serological parameters which were observed in the patient during that episode in addition to the nucleotide sequence of the virus isolate.

RESULTS AND CONCLUSION

In this patient parvovirus B19 was not the initial causative agent for SLE. However the B19 infection was followed by a severe flare of SLE and therefore may be considered as an enhancer of the autoimmune disease. The amount of nucleotide variability observed in the viral genome was in the range known from other B19 isolates. An elevated degree of mutations in antigenic domains was not detectable. Therefore, we would like to emphasize the possible role of parvovirus B19 in the aetiology or the enhancement of autoimmune diseases like SLE and the necessity of an according differential diagnosis.

A case of Guillain-Barré syndrome associated with human parvovirus B19 infection

We report a 4-year-old boy who presented with Guillain-Barré Syndrome 11 days after the onset of erythema infectiosum. The illness resolved without gamma globulin therapy.

Rheumatic manifestations of parvovirus B19 infection

Human parvovirus B19 is an emerging DNA virus. B19 infection is common and widespread. Major manifestations of B19 infection are transient aplastic crisis, erythema infectiosum, hydrops fetalis, acute and chronic rheumatoid-like arthropathy, and, in the immunocompromised host, chronic or recurrent bone marrow suppression. A number of less common manifestations of B19 infection include various rash illnesses, neuropathies, and acute fulminant liver failure. Of rheumatologic interest, B19 infection must be differentiated from early presentation of more classic erosive rheumatoid arthritis and, in some cases, systemic lupus erythematosus. It is unlikely that B19 plays a role in classic erosive rheumatoid arthritis, but understanding pathogenesis of B19 arthropathy may provide insights into the mechanisms by which rheumatoid arthritis develops. Evidence for persistence of B19 infection suggests that human parvovirus B19 infection may serve as a model for the study of virus-host interactions and the role of viruses in the pathogenesis of rheumatic diseases.

Human parvovirus B19 and blood products

BACKGROUND AND OBJECTIVES

Human B19 parvovirus (B19), identified in 1975, was only recognised as the causative agent of fifth disease in 1983. The incidence of viraemia is low, around 1 in 1,000, but is sufficient to ensure that most plasma pools for fractionation contain some virus. While infection usually occurs in childhood and is benign, chronic infection sometimes occurs and may be of concern in certain patient groups.

MATERIALS AND METHODS

This review is based on a meeting held in March 1995, and addresses recent concerns regarding the potential transmission of B19 infection by pooled plasma products.

RESULTS

Recent data on the pathophysiology and assay of this virus are summarised along with possible approaches to donor screening, product screening, and virus removal. Only five cases of symptomatic infection have been reported in persons with haemophilia, but no technology for virus removal is established, and infection may be of concern in pregnant women, and in patients with enhanced red cell turnover or who are immunosuppressed, including those infected with human immunodeficiency virus, but only rarely in immunocompetent patients.

CONCLUSIONS

For the future, well-validated assays relevant to virus infectivity are required if blood donations, plasma pools, or plasma products are to be screened, and an in-process virus inactivation step for B19 would be highly desirable. In the interim, non-plasma or recombinant products or a selective transfusion policy might be used in patient groups in which B19 infection is of particular concern. Further clinical data on the prognosis and impact of B19 infection are needed to justify both such policies and the future adoption of new technologies designed to reduce any excess B19 infectivity arising from transfused products.

[Severe parvovirus B19 infection in an immunocompetent child with hemophilia A]

BACKGROUND

B19 parvovirus is a widespread virus whose typical manifestations in immunocompetent children are erythema infectiosum, acute erythroblastopenia and fetal anemia.

CASE REPORT

An 11 year-old immunocompetent patient with hemophilia A was referred for an hemorrhagic syndrome. Forty days after a pasteurized coagulation factor concentrates treatment, and after 12 days of treatment with solvent/detergent factor VIII concentrates, he developed fever, consciousness disorders, pancytopenia, liver cytolysis and probably minor haemophagocytic syndrome, associated with human parvovirus B19 infection. His clinical state returned to normal within 15 days. A retrospective study revealed that the patient had received every day for 12 days, one parvovirus B19 polymerase chain reaction positive batch before the occurrence of symptoms.

CONCLUSION

This case highlights the possibility of severe parvovirus B19 infection transmitted by clotting factors prepared from large pools of plasma. The use of recombinant factors would allow to reduce human virus contamination, even if immune risk has to be more accurately assessed.

Persistent parvovirus B19 infections with different clinical outcomes in renal transplant recipients: diagnostic relevance of polymerase chain reaction (PCR) and of quantification of B19 DNA in sera

OBJECTIVE: To study parvovirus B19 infection in immunocompromised subjects such as renal transplantation recipients. METHODS: Two cases of B19 infection in renal transplant recipients have been included in the study. The outcome of the infection has been studied by both serologic and virologic methods. A monitoring of the DNAemia was done by a nested PCR in endpoint titration assays. RESULTS: In one patient with severe anemia an acute B19 infection was diagnosed by PCR 26 days after the transplant; a high level of DNAemia persisted until an intravenous immunoglobulin treatment. Then a sharp decrease of the DNAemia was shown, without full clearance of B19 virus. In a lymphocyte suspension from the organ donor, B19 DNA was detected. In the other patient, who recovered spontaneously from anemia, a persistent B19 infection was demonstrated at day 106 after transplantation and was still demonstrable after 470 days. CONCLUSIONS: A high level of B19 DNAemia was associated with symptomatic infection, with severe anemia, whereas low-level DNAemia was long-lasting in asymptomatic subjects with impaired immunologic responses. The endpoint titration assay by nested PCR was very useful for the monitoring of B19 infection, particularly following the therapeutic intravenous immunoglobulin administration.

Parvovirus B19 infection

Human parvovirus B19, discovered in 1974, is a single-stranded DNA virus which causes erythema infectiosum, arthralgia, aplastic crisis in patients with red cell defects, chronic anaemia in immunocompromised patients, and fetal hydrops. Seroprevalence in developed countries is 2-10% in children less than 5 years, 40-60% in adults more than 20 years, and 85% or more in those over 70 years. The virus may be transmitted by the respiratory route and by transfusion of infected blood and blood products. After an incubation period of six to eight days, viraemia occurs, during which reticulocyte numbers fall dramatically resulting in a temporary drop in haemoglobin of 1 g/dl in a normal person. Clearance of viraemia is dependent on development of specific antibody to the B19 structural proteins, VP1 and VP2. The red cell receptor for the virus is blood group P antigen. Diagnosis in immunocompetent persons depends on detection of specific IgM in serum. Diagnosis in immunocompromised persons depends on detection of B19 antigen or DNA in serum. There is no specific treatment for B19 infection; however, human normal immunoglobulin may be used as a source of specific antibody in chronically infected persons. A recombinant parvovirus B19 vaccine is under development.

Parvovirus B19 infection associated with encephalitis in a patient suffering from malignant lymphoma

A parvovirus B19 infection was established in a 58-year-old woman undergoing treatment for malignant lymphoma. Clinically, the patient displayed a variety of neurologic symptoms that could not readily be explained by the mere presence of lymphoblastic cells within the central nervous system. This is the first time parvovirus B19 DNA has been detected in the cerebrospinal fluid of a patient suffering from encephalitis.