Immunohistochemical study of mixed tumor of the skin with marked ossification

A seroepidemiological study was conducted in Kuwait to evaluate the pattern of acquisition of human parvovirus B19 by children in Kuwait and to compare it with patterns described in other regions in different climatic zones. A total of 218 serum samples from children less than 16 years of age were tested for the presence of anti-B19 IgG by enzyme immunoassay. The overall seroprevalence was 17.4%. Infants in Kuwait had low levels of maternally-acquired anti-B19 IgG (8.6%). The age of peak exposure to parvovirus B19 was 10-15 years compared with less than 10 years in England and Wales and more than 20 years in Singapore. The results of this study indicate an influence of geographic differences on transmission of parvovirus B19.     

The practice of dentistry in the drought areas of the west. 1935

An ultramicroELISA (UME) method was normalized for the detection of antibodies to serum human parvovirus B19. The optimum antigen concentration determined was 400 ng/ml, serum dilution was of 1:100; and the conjugate work dilution was of 1:2,000. 11 paired serum samples were also evaluated and antibodies were detected. The usefulness of the analyzed system is discussed.     

A novel parvovirus isolated from Manchurian chipmunks

A novel parvovirus was identified in Manchurian chipmunks inhabiting Korea. Hepatitis B surface antigen (HBsAg) was detected in sera from 4 animals among 62 apparently healthy chipmunks. Electron microscopic examination of the HBsAg-positive sera revealed virus-like spherical particles 20-22 nm in diameter. Extraction of nucleic acid under annealing conditions from the serum samples containing virus-like particles yielded a single species of DNA molecule with the electrophoretic mobility of 5.6-kb double-stranded DNA. Four overlapping clones that encompassed almost the full-length viral genome, except both ends, were obtained. By sequencing these clones, we determined the sequence of 5097 nucleotides of the viral DNA. Two open reading frames were identified, with the left side open reading frame encoding a putative nonstructural protein and the right side open reading frame encoding a putative capsid protein. The nucleotide and amino acid sequences showed significant homology to parvovirus B19 and simian parvovirus, but showed little homology to other mammalian autonomous parvoviruses or adeno-associated viruses. These observations indicate that the virus isolated from Manchurian chipmunks is a novel parvovirus and may be a potentially useful animal model of human B19 infection as a new member of the Erythrovirus genus of the Parvoviridae.     

Chemiluminescent microwell hybridization assay for direct detection of human parvovirus B19 DNA

A method for the direct detection of human parvovirus DNA in serum samples that uses a digoxigenin-labeled RNA probe to hybridize with target B19 DNA, followed by capture of the hybrid onto a microtiter plate wells previously coated with a second oligonucleotide probe was developed. The captured hybrid is then detected with anti-digoxigenin-alkaline phosphatase conjugate and chemiluminescent substrate and the reaction read on a scintillation counter. The relative sensitivities of the microwell and standard dot blot hybridization assays were compared. The chemiluminescent microwell hybridization assay was more sensitive than dot-blot hybridization and could be performed in a few hours. This format, therefore, permits rapid and sensitive detection of parvovirus DNA suitable for the clinical setting.     

Immunohistochemical and virological study of skin in the papular-purpuric gloves and socks syndrome

The pathogenesis of viral exanthems remains unclear. We have undertaken an immunohistochemical study of lesional skin biopsies in patients with the papular-purpuric gloves and socks syndrome (PPGSS) secondary to parvovirus B19 infection. Intracytoplasmic staining of the dermal endothelial cells, keratinocytes, and sweat glands was shown with an antibody to parvovirus B19. There were perivascular dermal infiltrates with T cells, sometimes with exocytosis. By polymerase chain reaction, virus DNA was detected in all skin biopsies and in one serum sample. The cutaneous manifestations of parvovirus infection seem secondary to infection of the endothelium and epidermis.     

Stepwise analysis of cerebral blood flow SPECT imaging on standard brain atlas in patients with dementia of Alzheimer''s type

In 1994 the first human parvovirus B19 (B19) epidemic to be documented in Denmark was recorded from February 2 to September 30. In total, 10,333 serum samples were tested for specific B19 IgM and IgG antibodies, using IDEIA Parvovirus B19 IgM and IgG kits. The prevalence of B19 IgM positivity was 11% for the whole period and 29% at the peak of the epidemic in week 14, declining from week 39 and onwards to 1-3%. The prevalence of B19 IgG (IgM-negative samples) was 60%, indicating an earlier infection, and the same for men and women. The gender distribution of tested patients was the same at the beginning of the epidemic as at the end of the epidemic and a year after its peak, i.e. 86% of samples were from women and only 14% from men. Age distribution for women was the same for the three periods (median age 34 years). For men the median age was 32 years, 39 years and 31 years, respectively. Only a few samples from children were tested. No change in test pattern was observed during the three periods. Approximately 75% of all samples tested were from women of childbearing age (18-45 years old), suggesting a fear of fetal complications in an actual or future pregnancy, rather than a serological verification of clinical symptoms. From the sparse clinical information that accompanied the serum sample we were not able to demonstrate that women were more likely than men to have a symptomatic B19 infection. With reservations we estimate that 14% of adverse pregnancy outcome is correlated with a B19 infection.     

The reinforced laryngeal mask airway (LMA) as an alternative airway device to manage the difficult airway

BACKGROUND: Infection with human parvovirus B19 (B19) has been reported in a few patients with various vasculitis syndromes. Mixed cryoglobulinaemia (MC), a model of small vessel size vasculitis, may result from numerous infectious diseases, particularly hepatitis C virus (HCV) infection. AIM: To assess the prevalence of seric B19 infection markers in a large series of patients with MC, with or without HCV infection. PATIENTS AND METHODS: Sixty-four patients were studied: essential MC (EMC, n = 19), MC associated with non-infectious diseases (non-essential MC, n = 9), and patients with HCV infection with (HCV-MC, n = 18) or without MC (HCV-no-MC, n = 18). Patients were considered to have MC if two successive determinations of their serum cryoglobulin concentration were above 0.05 g/l. Serum samples were analysed for specific IgG and IgM antibodies to B19 by enzyme immunoassay. B19 DNA detection was performed by polymerase chain reaction using a set of primers located in the VP1 gene, separately in serum and in cryoprecipitates to investigate a possible capture of B19 DNA in cryoprecipitate. The study also looked for a possible enrichment for of IgG antibodies to B19 in MC. RESULTS: The presence of specific IgG antibodies to B19 was found in 68% EMC, 56% non-essential MC, 78% HCV-MC, and 78% HCV-no-MC. No patient of either group had specific IgM antibodies to B19, or B19 DNA in serum or in cryoprecipitate. Overall, IgG antibodies to B19 were found in 46 of 64 (72%) serum samples, a prevalence quite similar to the prevalence in general adult population (> 60%). A specific enrichment of IgG antibodies to B19 in the MC was not found. CONCLUSION: These results suggest that B19 infection is neither an aetiological factor of EMC, nor a cofactor that may lead to MC production in patients with chronic HCV infection.     

Generation of neutralizing human monoclonal antibodies against parvovirus B19 proteins

Infections caused by human parvovirus B19 are known to be controlled mainly by neutralizing antibodies. To analyze the immune reaction against parvovirus B19 proteins, four cell lines secreting human immunoglobulin G monoclonal antibodies (MAbs) were generated from two healthy donors and one human immunodeficiency virus type 1-seropositive individual with high serum titers against parvovirus. One MAb is specific for nonstructural protein NS1 (MAb 1424), two MAbs are specific for the unique region of minor capsid protein VP1 (MAbs 1418-1 and 1418-16), and one MAb is directed to major capsid protein VP2 (MAb 860-55D). Two MAbs, 1418-1 and 1418-16, which were generated from the same individual have identity in the cDNA sequences encoding the variable domains, with the exception of four base pairs resulting in only one amino acid change in the light chain. The NS1- and VP1-specific MAbs interact with linear epitopes, whereas the recognized epitope in VP2 is conformational. The MAbs specific for the structural proteins display strong virus-neutralizing activity. The VP1- and VP2-specific MAbs have the capacity to neutralize 50% of infectious parvovirus B19 in vitro at 0.08 and 0.73 microgram/ml, respectively, demonstrating the importance of such antibodies in the clearance of B19 viremia. The NS1-specific MAb mediated weak neutralizing activity and required 47.7 micrograms/ml for 50% neutralization. The human MAbs with potent neutralizing activity could be used for immunotherapy of chronically B19 virus-infected individuals and acutely infected pregnant women. Furthermore, the knowledge gained regarding epitopes which induce strongly neutralizing antibodies may be important for vaccine development.     

A simple and sensitive DNA hybridization assay used for the routine diagnosis of human parvovirus B19 infection

A dot blot hybridization assay for parvovirus B19 diagnosis was developed by using a PCR-generated probe, digoxigenin labelling, and chemiluminescence detection. Different labelling techniques and hybridization solutions were evaluated. From this analysis a protocol was devised for routine diagnostic use. The protocol enabled 1 pg of B19 DNA to be detected. The results of applying this method to 8,369 diagnostic samples collected during 1994 and 1995 are given.     

Detection of mycoplasma infection of mammalian cells

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.     

IgG immune response to B19 parvovirus VP1 and VP2 linear epitopes by immunoblot assay

Human B19 parvovirus recombinant capsid proteins VP1 and VP2 were expressed in E. coli and purified. Recombinant proteins were used to detect a specific IgG immune response against VP1 and VP2 linear epitopes by immunoblot assay. A total of 222 serum samples from 218 apparently immunocompetent subjects with different clinical conditions and laboratory evaluations with regards to B19 infection were analyzed. The sera had previously been tested for B19 DNA and for specific IgM and IgG against VP2 conformational antigens by ELISA assay. The data show that, during the active or very recent phase of infection, IgG anti-VP1 linear epitopes appear in concomitance and with the same frequency as IgG anti-VP2 conformational antigens. IgG against conformational VP2 antigens and against linear VP1 epitopes seem to persist for months or years in the majority of individuals. IgG against VP2 linear epitopes are generally present during the active or very recent phase of infection and during the convalescent phase, while they are present only in about 20% of subjects with signs of a past B19 infection.     

Human parvovirus B19 infection. Update

Pathogenicity of parvovirus B19 has been demonstrated. The spectrum of clinical manifestations varies according to the age and immune status of affected patients. Parvovirus B19 is the aetiologic agent of erythema infectiosum in children. In normal adults, it is responsible for acute, bilateral and symmetrical arthritis, although chronic arthritis can develop. Parvovirus B19 has a particular tropism for erythroid precursors: in patients with underlying hemolysis, it induces transient aplastic crisis; in immunosuppressed patients the virus can lead to chronic pure red cell aplasia. Hydrops fetalis is one of the most severe manifestation of the infection. Diagnosis of recent parvovirus B19 infection is based upon serology and PCR, especially in immunosuppressed patients in whom polyvalent intravenous immunoglobulins must be started. The link between parvovirus B19 and systemic vasculitis is questioned.     

Improved algorithm for statistical batch-by-batch analysis of corneal topographic data

Congenital parvovirus infection was diagnosed in two liveborn premature infants born at 24 and 35 weeks of gestational age. The illnesses were associated with placentomegaly, petechial rash, edema, hepatomegaly, anemia and thrombocytopenia, respiratory insufficiency, and death at 5 and 6 days of age. The syndromes exhibited by these cases shared common but nonspecific features with other life-threatening congenital infections. Serological studies in one case supported the diagnosis of parvoviral infection. Postmortem examination of both revealed nuclear inclusions in erythroid precursor cells characteristic of parvovirus infection. Use of the polymerase chain reaction confirmed the presence of parvovirus DNA in one of the cases. Intrauterine parvovirus B19 infection is most commonly associated with hydrops fetalis, "transient" hydrops, or a favorable outcome in infants found to be viremic after birth. These and previously reported examples of congenital B19 disease exemplify an exceptional form of human parvovirus infection.     

Partial median sternotomy for pediatric cardiac surgery

There have been few reports on lymph node swelling in human parvovirus (HPV) B19 infection. A report of a 42-year-old female, who developed HPV B19-associated transient red cell aplasia with lymphadenopathy, is presented. The lymph node swelling began with the appearance of atypical lymphocytes in the peripheral blood and it disappeared as the patient recovered from the aplasia. Microscopically, the patient's bone marrow showed characteristic giant proerythroblasts with no maturation of the erythroid series. An excised inguinal lymph node showed florid, reactive follicular hyperplasia with paracortex expansion, and neutrophil infiltration and hemophagocytosis in the medullary sinus. These findings were compatible with the histology of a viral infection. A polymerase chain reaction study revealed HPV B19 in her serum and lymph node, but an immunohistochemical study failed to demonstrate HPV B19 capsid antigen in the lymph node or bone marrow. Although the present case suggests that reactive lymphadenopathy is associated with HPV B19 infection, the mechanism of the lymph node swelling still remains to be elucidated.     

Successful replication of parvovirus B19 in the human megakaryocytic leukemia cell line MB-02

The pathogenic human parvovirus B19 has been shown to undergo productive replication in the erythroid lineage in primary normal human hematopoietic progenitor cells. However, none of the established erythroleukemia cell lines has allowed B19 virus replication in vitro. The remarkable erythroid tissue tropism of B19 virus was evaluated with a human megakaryocytic leukemia cell line, MB-02, which is dependent on the growth factor granulocyte-macrophage colony-stimulating factor but can be induced to undergo erythroid differentiation following treatment with erythropoietin (Epo). Whereas these cells did not support B19 virus DNA replication in the presence of granulocyte-macrophage colony-stimulating factor alone, active viral DNA replication was observed if the cells were exposed to Epo for 5 to 10 days prior to B19 virus infection, as detected by the presence of the characteristic B19 virus DNA replicative intermediates on Southern blots. No replication occurred if the cells were treated with Epo for 3 days or less. In addition, complete expression of the B19 virus genome also occurred in Epo-treated MB-02 cells, as detected by Northern blot analysis. B19 progeny virions were released into culture supernatants that were biologically active in secondary infection of normal human bone marrow cells. The availability of the only homogeneous permanent cell line in which induction of erythroid differentiation leads to a permissive state for B19 virus replication in vitro promises to yield new and useful information on the molecular basis of the erythroid tissue tropism as well as parvovirus B19-induced pathogenesis.     

The wandering pacemaker: intraperitoneal migration of an epicardially placed pacemaker and femoral nerve stimulation

A human immunodeficiency virus (HIV)-infected individual was first diagnosed with red blood cell aplasia due to B19 parvovirus infection in late 1989. Over the subsequent seven-year period, he received a total of 119 units of red blood cells (RBCs) and intravenous immunoglobulin every 2-3 weeks. In 1996 combination antiretroviral treatment with a protease inhibitor was initiated. He received four more units during the following two months and then required no more transfusions for the subsequent 24 months of follow-up. His CD4 count progressively increased and DNA polymerase chain reaction for parvovirus B19 became undetectable. Aggressive antiretroviral treatment may effectively diminish transfusion requirements among HIV-infected individuals with pure RBC aplasia resulting from parvovirus B19 infection.     

Sex-associated differences in cold-induced UCP1 synthesis in rodent brown adipose tissue

OBJECTIVE: To evaluate the usefulness of new ELISA for human parvovirus B19 (B19) antibodies and PCR for the diagnosis of acute onset of B19 polyarthritis. METHODS: We evaluated the reproducibility and sensitivity on the detection of anti-B19 antibody by ELISA using recombinant VP-1 and VP-2 (empty particle), and then studied for the prevalence of IgM and IgG B19 antibody in 125 samples for anti-B19 tests. The random study on anti-B19 antibody assay as well as PCR for B19-DNA was also performed in 130 cases with acute onset of arthritis excluding those with known origins, 224 with rheumatoid arthritis and 149 with other categories. RESULTS: The results by using B19-empty particle ELISA were reproducible and showed the assay was a sensitive way for clinical use. IgM anti-B19 antibodies were positive not only in all samples from erythema infectiosum, but also often in those from hemolytic anemia, pure red cell aplasia, fetal hydrops, hepatic injury, fever of unknown origin. Among 130 with acute onset of arthritis, 21 showed positive tests for IgM anti-B19 antibody and/or B19 DNA. On the other hand, 4 among 224 patients with rheumatoid arthritis were positive for IgM anti-B19 antibody, but all of 149 in control group were negative for IgM anti-B19 antibodies and for B19 DNA. CONCLUSION AND DISCUSSION: Anti-B19 ELISA using B19-empty particle which has been introduced as a routine test system, is a useful tool for the diagnosis of acute onset of B19 arthritis. An additional examination using PCR for B19 DNA may contribute for understanding persistent B19 polyarthritis or reactivation of B19 infection.     

UDP-glucuronosyltransferase in Gilbert''s syndrome

BACKGROUND: The long-term consequences of parvovirus B19 infection in transfusion recipients are not known, and thus the value of B19 screening of blood donors remains unresolved. Hemophiliacs, at risk for B19 through their chronic exposure to clotting factor concentrates, have frequent, close medical follow-up and thereby constitute an ideal group in which to study the hematologic sequelae of B19 infection. STUDY DESIGN AND METHODS: An enzyme-linked immunosorbent assay was used to detect B19 IgG and IgM and the polymerase chain reaction was used to detect B19 DNA in frozen, stored plasma samples, obtained between 1987 and 1994, from 136 subjects with hemophilia, including 71 who were human immunodeficiency virus (HIV)-positive and 65 who were HIV-negative. Then the results of the tests were compared with clinical hematological data and blood product usage data. RESULTS: B19 seroprevalence in the hemophilic cohort was 81.6 percent (111/136), including 74.6 percent (53/71) of HIV-positive and 89.2 percent (58/65) of HIV-negative hemophiliacs. It was not affected by age, type or severity of hemophilia, HIV status, CD4 number, or yearly blood product usage. Only 1 (0.7%) of the 136 samples was positive for B19 IgM and none was positive in polymerase chain reaction for B19 DNA. After adjusting for HIV status, there were no differences between B19-positive and B19-negative hemophiliacs in hematologic values, CD4 counts, or blood product use. CONCLUSION: Although B19 IgG seroprevalence in this hemophilic cohort is high and indicative of past B19 infection, there is no detectable B19 viral activity or any associated long-term clinical or hematologic sequelae.     

Bilateral brachial plexus neuritis following parvovirus B19 and cytomegalovirus infection

A man, 23 years of age, had a typical erythema infectiosum, complicated by a severe bilateral brachial plexus neuritis. Motor function recovered slowly and only partially after 6 months. An infection by human parvovirus B19 was demonstrated, with strongly positive and gradually declining IgM antibodies and viral DNA detectable in serum for more than 3 months. There was also clear evidence of a recent infection by cytomegalovirus. The interaction between these two viruses could be responsible for this rare and severe complication of common infections in this patient.     

Spectrum of parvovirus B19 infection: analysis of an outbreak of 43 cases in Cadiz, Spain

In the spring of 1993, an epidemic of infection with human parvovirus B19 occurred in Cadiz, Spain. Evaluation of the 43 patients in whom this diagnosis was confirmed revealed four groups of predominant manifestations: (1) hematologic manifestations in six cases (13.9%), including four of aplastic crisis and two of pancytopenia; (2) dermatologic manifestations in 23 cases (53.4%), including 10 of erythema infectiosum and one of erythema multiforme ampullosum; (3) arthralgias/arthritis in nine cases (20.9%), including two with a chronic course; and (4) infection during pregnancy in three cases (7.0%), including two that ended in abortion. Of the 43 patients, 37.2% presented with fever and adenopathies, and these were the only manifestations in two cases. The appearance of clinical disease correlated with modifications in isotype and serum level of specific antibodies to parvovirus B19; the disappearance of IgM antibodies coincided with the resolution of clinical manifestations. Although their presence did not correlate with the course of the disease, the detection of circulating immune complexes in 81.6% of cases supports the possibility that some manifestations were immune mediated.