Relevance of B19 markers in serum samples for a diagnosis of parvovirus B19-correlated diseases

Algorithm for laboratory diagnostics of parvoviral infection in risk groups

Parvovirus infection (PVI) is widespread, characterized by airborne, bloodborne and vertical transmission routes. Parvovirus B19 (PVB19) exhibits tropism to erythropoietic cells. According to the increased likelihood principle of PVB19 infection and the severity of the consequences, immunocompromised individuals, especially those with hematological manifestations of diseases, are in increased risk group. Based on the own research results and analysis of the published data, we have proposed specific algorithms for PVI laboratory testing in individual risk groups, taking into account the peculiarities of the development and infection manifestation in each group: in HIV-infected patients, in oncohematological patients with to whom allogeneic hematopoietic stem cell transplantation (allo-HSCT) have been prescribed (blood and bone marrow recipients), as well as in patients with chronic anemia of parasitic etiology. For each group, the main clinical or laboratory marker, treatment procedure, or patient physiological parameters have been determined, based on which it was recommended to test for PVI. For HIV-infected patients, the main criterion for PVI testing is persistent anemia. For oncohematological patients, the basis for PVI testing is allo-HSCT procedure, which is planned or performed for this particular patient. For malaria patients, the patient's age was considered as major criterion, since in malaria and PVI coinfected young children can lead to a fatal outcome. The proposed PVI diagnostics algorithms usein risk groups can help to predict the severe course of underlying disease associated with PVB19 infection, and timely correct the therapy used.

A cross-sectional study on risk factors for infection with Parvovirus B19 and the association with anaemia in a febrile paediatric population in Ghana

Parvovirus B19 (B19V) occurs globally and can cause severe anaemia. The role of co-infections with Plasmodium falciparum (P. falciparum) has been controversially discussed. The study aimed to determine prevalence and severity of B19V infection, and the effect of co-infections on the risk for anaemia. Between November 2013 and April 2015 a total of 1186 hospital visits of children with fever admitted to a hospital in Ghana were recorded. Malaria, B19V and additional diagnostics for fever causes were performed. Recent B19V infection was defined as PCR and/or IgM positivity. Risk factors for a B19V infection and for anaemia were analysed. The prevalence of anaemia was compared between children with/without B19V infection, stratified for the presence of malaria. B19V IgM/PCR was positive in 6.4% (n = 76; 40 IgM + , 30 PCR + , 6 IgM + and PCR +). Among the B19V cases 60.5% had a simultaneous P. falciparum infection. B19V IgM positivity but not PCR positivity was associated with moderate-severe anaemia (OR = 2.6; 95%-CI: 1.3-5.3; P < 0.01 vs. OR = 0.9; 95%-CI: 0.4-1.8; P = 0.70). P. falciparum and IgM positive B19V infection were independent risk factors for anaemia with no evidence of effect modification. Our data show a significant association between B19V infection, defined as IgM but not PCR positivity, and moderate-severe anaemia. A multiplicative effect of B19V and P. falciparum infection was not found.

An Outbreak of Human Parvovirus B19 Hidden by Dengue Fever

BACKGROUND

Seasonal outbreaks of dengue often result in hundreds of dengue-suspected cases where a clinical diagnosis cannot be confirmed. Usually, during large outbreaks of dengue and other pathogens that can cause acute febrile illnesses, the search for secondary pathogens with similar disease outcomes is rare.

METHODS

Using total RNA sequencing and targeted diagnostic assays, we discovered an outbreak of parvovirus B19 in dengue-suspected patients that occurred from November 2013 to February 2014.

RESULTS

Of the 182 cases investigated, 63% were viremic for the B19 virus. Moreover, we found that >43% of infected patients had no serological evidence of prior infection. Parvovirus B19 is a typical childhood infection, yet we observed that 82% of the infected patients were adults. Additionally, we perceived that infected adults had significantly higher presentations of myalgia than in children. We also obtained viral protein (VP) 1/VP2 gene nucleotide sequences from 43 patients.

CONCLUSIONS

Our results support the utility of next-generation sequencing for symptomatic patients with unknown etiologies during seasonal outbreaks of dengue and other arborviruses. Our findings could improve the vigilance of hospitals and laboratories by raising awareness of co-circulating pathogens such as parvovirus B19 that may be hidden in plain sight.

History of parvovirus B19 infection is associated with silent cerebral infarcts

BACKGROUND

The relationship between silent cerebral infarcts (SCIs) and history of parvovirus B19 (B19V) has not been systematically evaluated. As an ancillary study from the Silent Cerebral Infarct Trial (SIT) (NCT00072761), we tested the hypothesis that a history of B19V infection is associated with an increased prevalence of SCIs in children with sickle cell anemia.

PROCEDURE

We used a retrospective cross-sectional cohort study design; each participant underwent a brain magnetic resonance imaging (MRI) scan and medical record review for prior B19V infection (n = 958).

RESULTS

SCI was present in 30% (287 of 958) of participants and 17% (165 of 958) had a history of B19V infection. Based on prior evidence that low baseline hemoglobin (Hgb) levels are associated with increased odds of SCI, Hgb levels were divided into tertiles (<7.6 g/dl, ≥7.6-≤8.5 g/dl, ≥8.6 g/dl) and multivariable analysis was used to determine the relationship between the joint effect of prior B19V infection, Hgb levels, and SCI. Prior B19V infection and the lowest Hgb tertile were associated with increased risk of SCI (odds ratio [OR] 2.12; 95% CI, 1.17-3.84; P = 0.013); no prior B19V infection and the highest Hgb tertile were associated with a decreased risk (OR 0.56; 95% CI, 0.38-0.84; P = 0.004).

CONCLUSIONS

Efforts to decrease the incidence of B19V infection, such as the development of a B19V vaccine, may decrease SCI prevalence.

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.

Genotype 3b of human parvovirus B19 detected from hospitalized children with solid malignancies in a North Indian tertiary care hospital

Human parvovirus B19 (B19V) infection is known to cause serious consequences in immuno-compromized individuals. The present cross sectional study was designed to estimate the prevalence and genotype distribution of B19V in children receiving chemotherapy for solid malignancies at a tertiary care hospital in North India during October 2013 to May 2015. Serum samples from all the patients were tested for anti-B19V IgM and IgG antibodies and for B19V-DNA as soon as received. Samples testing positive for B19V-DNA were subjected to viral load estimation and to genotype determination by sequencing. Total 96 children were enrolled of which 9 (9.3%), 32 (33.3%), and 25 (26%) tested positive for anti-B19V IgM, anti-B19V IgG, and B19V-DNA, respectively. The viral load of B19V-DNA positive children ranged from 5.5 × 10(2) to 3.5 × 10(12) copies/ml. Accordingly children were divided into three groups: group I, with acute infection (n = 25); group II, previously exposed (n = 27), and group III, negative for B19V infection or with inappropriate antibody response (n = 44). B19V positivity was significantly associated (P-value < 0.0001) with a history of blood transfusion in the past 6 months, severe anemia (hemoglobin levels <6 gm%) and thrombocytopenia (platelets <150,000/cu.mm.). Sequence analysis of 21 of 25 DNA positive samples showed that all of them were Genotype 3b that clustered into three groups. All the sequences within each cluster were identical. The nucleotide identity of the sequences suggests a nosocomial outbreak of B19V during the study period. Children on chemotherapy for solid tumors should be routinely screened for B19V infection by both serology and PCR. J. Med. Virol. 88:1922-1929, 2016. © 2016 Wiley Periodicals, Inc.

Parvovirus B19 Achievements and Challenges

Parvovirus B19 is a widespread human pathogenic virus, member of the Erythrovirus genus in the Parvoviridae family. Infection can be associated with an ample range of pathologies and clinical manifestations, whose characteristics and outcomes depend on the interplay between the pathogenetic potential of the virus, its adaptation to different cellular environments, and the physiological and immune status of the infected individuals. The scope of this review is the advances in knowledge on the biological characteristics of the virus and of virus-host relationships; in particular, the interactions of the virus with different cellular environments in terms of tropism and ability to achieve a productive replicative cycle, or, on the contrary, to establish persistence; the consequences of infection in terms of interference with the cell physiology; the process of recognition of the virus by the innate or adaptive immune system, hence the role of the immune system in controlling the infection or in the development of clinical manifestations. Linked to these issues is the continuous effort to develop better diagnostic algorithms and methods and the need for development of prophylactic and therapeutic options for B19V infections.

Parvovirus b19 infection localized in the intestinal mucosa and associated with severe inflammatory bowel disease

Infection by human parvovirus B19 is widespread and can be associated with a wide range of different pathologies and clinical manifestations. We provide the first evidence of localization of an active parvovirus B19 infection in the intestinal mucosa and its association with a severe inflammatory bowel disease, characterized by duodenal villous atrophy with increased intraepithelial lymphocytes and inflammatory infiltrates in the colonic mucosa. Virus in the intestinal mucosa was detected in cells of the inflammatory infiltrate, identified as T lymphocytes and selectively localized in sites of active tissue degeneration.

Macaque models of human infectious disease

Macaques have served as models for more than 70 human infectious diseases of diverse etiologies, including a multitude of agents—bacteria, viruses, fungi, parasites, prions. The remarkable diversity of human infectious diseases that have been modeled in the macaque includes global, childhood, and tropical diseases as well as newly emergent, sexually transmitted, oncogenic, degenerative neurologic, potential bioterrorism, and miscellaneous other diseases. Historically, macaques played a major role in establishing the etiology of yellow fever, polio, and prion diseases. With rare exceptions (Chagas disease, bartonellosis), all of the infectious diseases in this review are of Old World origin. Perhaps most surprising is the large number of tropical (16), newly emergent (7), and bioterrorism diseases (9) that have been modeled in macaques. Many of these human diseases (e.g., AIDS, hepatitis E, bartonellosis) are a consequence of zoonotic infection. However, infectious agents of certain diseases, including measles and tuberculosis, can sometimes go both ways, and thus several human pathogens are threats to nonhuman primates including macaques. Through experimental studies in macaques, researchers have gained insight into pathogenic mechanisms and novel treatment and vaccine approaches for many human infectious diseases, most notably acquired immunodeficiency syndrome (AIDS), which is caused by infection with human immunodeficiency virus (HIV). Other infectious agents for which macaques have been a uniquely valuable resource for biomedical research, and particularly vaccinology, include influenza virus, paramyxoviruses, flaviviruses, arenaviruses, hepatitis E virus, papillomavirus, smallpox virus, Mycobacteria, Bacillus anthracis, Helicobacter pylori, Yersinia pestis, and Plasmodium species. This review summarizes the extensive past and present research on macaque models of human infectious disease.

ELISAs using human bocavirus VP2 virus-like particles for detection of antibodies against HBoV

Human bocavirus (HBoV) has been identified worldwide in children with lower respiratory tract infections with an incidence of approximately 2–11%. The role of HBoV in pathogenesis, however, is largely unknown, and little is known about the epidemiology of the virus. To study the seroepidemiology of HBoV infection, the capsid protein was expressed in insect cells. Expression of the putative major capsid protein VP2 in insect cells led to the formation of virus-like particles exhibiting the typical icosahedral appearance of parvoviruses with a diameter of approximately 20 nm. The expressed particles were used to establish an enzyme-linked immunosorbent assay (ELISA) method, and serum samples from groups of children of various ages in China were tested for IgG antibodies against HBoV. HBoV antibodies were detected in as high as 36% of healthy children under 9 years. Of children hospitalized with lower respiratory tract infections, 31% were seropositive, and all age groups of these children showed a significantly higher level of HBoV IgG antibody than their healthy counterparts. When divided into age cohorts, results showed that more than 48% of healthy children had seroconverted by age of 4. Thus, HBoV appears to be a common infection in children. The potential pathogenesis of this virus, especially its role in lower respiratory tract infections in children warrants further investigation.

Competitive PCR-ELISA protocols for the quantitative and the standardized detection of viral genomes

Competitive PCR-ELISA combines competitive PCR with an ELISA to allow quantitative detection of PCR products. It is based on the inclusion of an internal standard competitor molecule that is designed to differ from the target by a short sequence of nucleotides. Once such a competitor molecule has been designed and constructed, target and competitor sequences are concurrently PCR-amplified, before hybridization to two different specific probes and determination of their respective OD values by ELISA. The target can be quantified in relation to a titration curve of different dilutions of the competitor. The competitor can alternatively be used at a unique optimal concentration to allow for standardized detection of the target sequence. PCR-ELISA can be performed in 1 d in laboratories without access to a real-time PCR thermocycler. This technique is applied in diagnostics to monitor the course of infections and drug efficacy. Competitive PCR-ELISA protocols for the quantitative and for the standardized detection of parvovirus B19 are detailed here as an example of the technique.

Relevance of specific immunoglobulin M and immunoglobulin G for parvovirus B19 diagnosis in patients with acute lymphoblastic leukemia receiving chemotherapy: prospective study

CONTEXT

Immunocompromised patients suffer from prolonged viral infections often without detectable immune response. However, even if the immune response occurs, can it clear the virus completely?

OBJECTIVE

To detect parvovirus B19 DNA and its antibodies in bone marrow cells and in serum by polymerase chain reaction (PCR) in children with acute lymphoblastic leukemia receiving chemotherapy to highlight the relation of humoral immune response to the presence of viremia. Also, to evaluate the optimal diagnostic test(s) for a correct diagnosis of parvovirus B19 disease in immunocompromised patients.

DESIGN

Forty-eight children with acute lymphoblastic leukemia receiving maintenance chemotherapy were included in the study in addition to 20 healthy children with matched age and sex. Study for parvovirus B19 was performed by serologic determination of specific immunoglobulin (Ig) M and IgG, and viral DNA was determined by PCR in both serum and bone marrow aspiration.

RESULTS

Parvovirus B19 DNA was detected in both serum and bone marrow in 20% of patients. Specific IgG was found in 40% and IgM in 26.7%. Two cases (10%) in the control group were positive for IgG. The agreement between IgG and positive results of PCR in the bone marrow was 33.3%, and the agreement for IgM and PCR in the serum was 33.3%.

CONCLUSIONS

Parvovirus B19 is considered a common viral infection in children with acute lymphoblastic leukemia receiving chemotherapy. We must use our full potential to exclude such infection, which can mimic the side effects of chemotherapy in these patients. In immunocompromised patients, there are immunologic discrepancies in humoral immune responses for both IgM and IgG between individuals with parvovirus B19 persistence and healthy individuals, findings that may reflect both failed immunity and antigenic exhaustion. The contemporaneous determination of parvovirus B19 DNA by PCR in both bone marrow and peripheral blood and specific serologic markers appears to be the most appropriate diagnostic protocol for the correct laboratory diagnosis of parvovirus B19 infection in these patients.

Parvovirus B19 infection in Chile: markers of infection and immunity in patients with clinical symptoms

Parvovirus B19 infection is associated with a wide variety of symptoms and signs, and given that some clinical features, such as anemia, arthropathy and rash may be attributable to other causes, laboratory diagnosis of B19 markers is necessary. The principal aims were to study the behavior of B19 infection-associated diseases in the Chilean population and to compare B19 markers for recent or active infection and for immunity status in patients with clinical symptoms suspicious of B19 infection and control individuals. Sera from a total of 267 patients with diverse clinical manifestations associated with B19 and from 69 healthy controls were tested for B19 DNA using PCR and for specific IgM and immunoglobulin G (IgG) by enzyme-linked immunosorbent assay (ELISA). Out of 267 patients examined, 89 had B19-associated disease markers: 43 had B19 DNA without IgM, 25 had IgM without B19 DNA, and 21 had both B19 DNA and IgM. Also 49 patients were positive only for IgG without B19 DNA or IgM. Out of the 69 healthy controls, only 2 had B19 DNA without IgM and 30 had IgG without B19 DNA and/or IgM. The distribution of the clinical diagnoses associated with recent B19 infection, tested by B19 DNA and/or IgM, included 38.5% with hematological illnesses, 23.4% with rheumatic diseases, 45.7% with infectious diseases, 33.3% with indications of prenatal infection, 32.3% with conditions that induce immunodeficiency, and 15.8% with other miscellaneous conditions. The use of both markers, DNA and IgM, allows a more adequate diagnosis of infection by this virus.

Relevance of parvovirus B19, herpes simplex virus 2, and cytomegalovirus virologic markers in maternal serum for diagnosis of unexplained recurrent abortions

CONTEXT

The impact of viral infections during pregnancy on adverse pregnancy outcomes is not understood fully.

OBJECTIVE

To assess the frequency of parvovirus B19, herpes simplex 2, and cytomegalovirus infections in relation to late abortions, in sera from Egyptian pregnant women to establish basic knowledge for future pregnancy care. In addition, to study the diagnostic value of specific immunoglobulin M (IgM) against those viruses compared with their genomes detection by polymerase chain reaction in maternal serum as a noninvasive method of laboratory diagnosis.

DESIGN

Patients were recruited at the Women's Clinic, Mansoura University. One group of patients with recurrent spontaneous abortions (RSA) and a second group of pregnant women without a history of RSA were evaluated including demographic, medical, and clinical data. Virologic markers were evaluated for specific IgM and for viral DNA to cytomegalovirus, herpes simplex virus 2, and parvovirus B19.

RESULTS

There was a statistically significant difference between the RSA group and the pregnant women without RSA group in frequency of parvovirus IgM (84% and 16.7%, respectively) (P < .001) and herpes simplex IgM (40% for RSA) (P = .001). Parvovirus B19 viremia was positive in 48% RSA, herpes simplex virus 2 was positive in 32% RSA, and cytomegalovirus was positive in 12% RSA patients. For RSA patients with parvovirus viremia, the mean +/- SD of IgM value was 78.5 +/- 30.12 IU/mL, and for RSA patients with negative viremia it was 30.02 +/- 17.64 IU/mL with statistically significant difference between both levels (P < .001).

CONCLUSIONS

From this study, we conclude that viral infections with parvovirus B19 and herpes simplex 2 were frequently associated with recurrent abortions, and careful investigation for this condition must include evaluating these patients for the previously mentioned viruses. Serologic study by specific IgM for parvovirus and herpes simplex seem to be reliable as screening tests for high-risk pregnancy.

Concurrent detection of human herpesvirus type 6 and measles-specific IgMs during acute exanthematic human parvovirus B19 infection

A familial outbreak of human parvovirus B19 infection is described in which serological tests carried out routinely for determining the causal agent of febrile rashes of viral etiology failed to yield a definitive diagnosis. Concurrent detection of serum IgMs to parvovirus B19 and to heterologous viruses such as human herpesvirus type 6 (HHV-6) and measles virus complicated interpretation of the data. IgG avidity tests and investigation and testing for the presence of viral DNA in sera by PCR were required to confirm parvovirus B19. The study stresses the importance of avidity and PCR tests to obtain a firm diagnosis of febrile exanthematic viral diseases.

The association of VP1 unique region protein in acute parvovirus B19 infection and anti-phospholipid antibody production

BACKGROUND

Previous studies have postulated a connection between human parvovirus B19 (B19) infection and anti-phospholipid antibodies (aPL). Recently, the phospholipase domain of B19 has been linked to B19-VP1 unique region (VP1u). To elucidate the roles of VP1u in B19 infection and aPL production, the major reactivity of anti-B19-VP1u, anti-cardiolipin antibody (aCL), and anti-beta2-glycoprotein I (beta2GPI) antibody was evaluated.

METHODS

Sera from 102 clinically suspected cases of B19 infection were analyzed by nested PCR and ELISA. Humoral responses of anti-B19-VP1u and anti-B19-VP1uD175A IgM/IgG antibodies, aCL and the anti-beta2GPI antibody were assessed by Western blot and ELISA. Absorption experiments were also performed to determine the binding specificity of immunoglobulins to B19-VP1u, CL and beta2GPI.

RESULTS

Sera from patients with the diagnostic pattern DNA+/IgM+/IgG+ had a high frequency (57%) for recognition of CL and beta2GPI. Furthermore, adsorption experiments were performed by adding purified B19-VP1u, which partially suppressed the reactivity of anti-B19VP1u to CL and beta2GPI.

CONCLUSIONS

Serum from patients with acute B19 infection has a high frequency in recognition of CL and beta2GPI, and the phospholipase domain observed in the B19-VP1u may have contributed to the production of aPL. These findings may provide a clue for understanding the roles of B19-VP1u in B19 infection and aPL production.

Sensitive and rapid diagnosis of human parvovirus B19 infection by loop-mediated isothermal amplification

BACKGROUND

Human parvovirus B19 (B19) infections exhibit various skin manifestations that are similar to and hence hard to distinguish from many other skin diseases. The virological diagnosis of B19 infection is usually based on time-consuming serological tests and polymerase chain reaction (PCR).

OBJECTIVES

In this study, a DNA amplification method, loop-mediated isothermal amplification (LAMP), was used for the diagnosis of B19 infection and was compared with PCR.

METHODS

Ten patients with acute B19 infection and 16 patients with other skin diseases were enrolled. Sera and pharyngeal swabs were used directly as the templates in LAMP. The LAMP reaction was carried out at 63 degrees C for 1 h in a heat block. The reaction products were judged visually, by adding SYBR Green I into the tubes, and by gel electrophoresis.

RESULTS

B19 DNA was detected by LAMP in 10 sera and all of seven tested pharyngeal swabs of 10 patients with acute B19 infection but not in samples from 16 patients with other skin diseases. The results were in agreement with those obtained by PCR except for one case. The reason for the single discrepancy may be that the sensitivity of LAMP is 10(2) times higher than PCR.

CONCLUSIONS

Detection of B19 DNA by LAMP in serum and especially in the pharynx is a rapid and convenient method for the diagnosis of acute B19 infection.

Parvovirus B19 infections in state of Rio de Janeiro, Brazil: 526 sera analyzed by IgM-enzyme-linked immunosorbent assay and polymerase chain reaction

In this study were analyzed 526 sera; the patients aged from two days to 65 years old presenting exanthema, which was the most frequent symptom observed, besides fever, adenomegaly, and arthralgia. These sera were negative by enzyme-linked immunosorbent assay (IgM-ELISA) for either rubella (495), toxoplasma (41), cytomegalovirus (12), measles (40), dengue (56), and they were submitted to nested polymerase chain reaction (PCR) for B19 DNA and commercial IgM-ELISA for B19. In 39 abortion cases, IgM or DNA were not detected, therefore they were not took into account for analysis. Specific DNA and IgM were detected respectively in 71 (14.5%) and IgM in 62 (12.7%) sera from 487 sera analyzed. IgM and DNA were simultaneously detected in 43 (8.8%), while agreement among the results by PCR and IgM-ELISA was observed in 440 (90.4%). The sera were collected from January 1999 to December 2000, most of them in 1999 (325), during winter and spring. The major number of clinical cases was observed in the age group from one to ten years old. IgM or DNA were detected in 23 from 51 municipal districts of the state of Rio de Janeiro, where the samples were collected.

Simultaneous occurrence of pure red cell aplasia and papular-purpuric 'gloves and socks' syndrome in parvovirus B-19 infection

Papular-purpuric 'gloves and socks' syndrome (PPGSS) has been associated with parvovirus B-19 infection. We report a case of an adult immunocompetent male who presented with PPGSS. Bone marrow examination revealed pure red cell aplasia. Parvovirus B-19 DNA was detected by polymerase chain reaction in the patient's serum, whole blood and in the cutaneous lesions. This report illustrates the variety of clinical manifestations caused by B-19 infection, presents for the first time the concurrent appearance of pure red cell aplasia and PPGSS in the same patient and, finally, suggests that PPGSS may be due to direct lytic effect of the virus.

Human parvovirus B19 infection in patients with chronic hepatitis B or hepatitis C infection

BACKGROUND AND AIM

Parvovirus B19 has been reported to be detected in the sera of patients with acute or chronic hepatitis. The prevalence and clinical significance of B19 DNA in serum samples from patients with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection were investigated.

METHODS

Serum samples from 54 patients with HBV infection, 51 with HCV infection and 53 normal controls were examined for anti-B19 antibodies and B19 DNA by enzyme-linked immunosorbent assay (ELISA), the nested polymerase chain reaction (PCR), Southern blotting and direct nucleotide sequencing, respectively.

RESULTS

Anti-B19 IgM and IgG antibodies were detected in 19 (35.2%) and 46 (85.2%) of 54 serum samples from patients with HBV infection, and eight (15.7%) and 36 (70.6%) of 51 serum samples from patients with HCV infection. B19 DNA was detected in serum samples of 20 (37%) of 54 patients with HBV infection and 12 (23.5%) of 51 patients with HCV infection, but not in 53 serum samples from normal controls. The occurrence of liver dysfunction was not affected by B19 infection in patients with HBV and HCV infection (P > 0.05). All of the 20 serum samples with B19 DNA from patients with chronic HBV infection and all of the 12 serum samples with B19 DNA from patients with chronic HCV infection exhibited TW-3 subtype and TW-9 subtype, respectively. The variant subtypes of B19 were found to be distinctive in patients with HBV or HCV infection.

CONCLUSIONS

These data revealed that human parvovirus B19 infection was frequently found in patients with chronic HBV or HCV infection. The variant genotypes were present in patients with different chronic hepatitis. The coinfection of B19 with HBV or HCV did not increase the frequency of liver dysfunction in patients with chronic hepatitis. Long-term longitudinal studies are required to determine the natural course of parvovirus B19 infection and whether its coinfection affects the natural history of chronic hepatitis B or hepatitis C.

An adult with aplastic crisis induced by human parvovirus B19 as an initial presentation of hereditary spherocytosis

The association between aplastic crisis and human parvovirus (HPV) B19 infection is well described in patients with sickle cell anemia. This association has also been described, although much less frequently, in patients with hereditary spherocytosis (HS). However, most cases of aplastic crises in patients with HS and induced by HPV B19 have been reported in children or adolescents. In this paper, we describe an aplastic crisis induced by HPV B19 in an adult with HS. A 34-year-old female presented with presyncope, febrile sensation, and myalgia. The complete blood counts showed severe anemia. The peripheral blood smear revealed spherocytosis with reticulocytopenia and pancytopenia. The direct Coombs' test was negative; the osmotic fragility test was positive. In the bone marrow aspirates, a few giant pronormoblasts with deep blue cytoplasm, pseudopods, and intracellular inclusion bodies were observed. The patient was given eight units of packed red blood cells. HPV B19 infection was proven by the presence of IgM antibodies to HPV B19 and the detection of viral DNA using the PCR technique. To the best of our knowledge, this is the first report in Korea that describes an adult with aplastic crisis presenting initially with HS.

Persistent human parvovirus B19 infection in children under maintenance chemotherapy for acute lymphocytic leukemia

OBJECTIVE

To report on B19 infection management and chemotherapy schedule consequences in five children treated for acute lymphocytic leukemia (ALL).

PATIENTS AND METHODS

Between May 2001 and February 2002, five patients between 4 and 12 years of age, receiving maintenance chemotherapy for ALL, presented with symptoms suggesting B19 infection (pallor, fatigue, petechiae and pancytopenia in four patients; generalized rash in two patients; acute hepatitis in one patient). Qualitative polymerase chain reaction (PCR) on peripheral blood was used for diagnosis and follow-up of infection; quantitative PCR was used for viral load measurement. Intravenous nonspecific high-dose immunoglobulin therapy was administered until PCR was negative.

RESULTS

Qualitative B19 DNA was found in the peripheral blood of all patients, confirming the infection. Viral load at diagnosis ranged from 10 to 10 particles/mL blood. B19 DNA was detectable in four patients at 45, 21, 40, and 44 weeks, respectively. Chemotherapy was delayed in all patients. No clear benefit of intravenous immunoglobulin was noted.

CONCLUSIONS

Infection with B19 is rarely reported in patients with ALL, but it should be suspected when unexplained pancytopenia occurs during chemotherapy. Persistent B19 infection remains a challenge in the management of patients receiving maintenance chemotherapy for ALL, as no specific therapy such as a specific immunoglobulin or vaccine exists. The role of viral load measurement needs to be established in terms of its use in follow-up and evaluation of the therapeutic response.