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.

Human Parvovirus B19

The nucleotide sequence of an almost-full-length clone of human parvovirus B19 was determined. Whereas the extreme left and right ends of this genomic clone are incomplete, the sequence clearly indicates that the two ends of viral DNA are related by inverted terminal repeats similar to those of the Dependovirus genus. The coding regions are complete in the cloned DNA, and the two large open reading frames which span almost the entire genome are restricted to one strand, as has been found for all other parvoviruses characterized to date. From the DNA sequence we conclude that the organization of the B19 transcription units is similar although not identical to those of other parvoviruses. In particular, we predict that the B19 genome may utilize a fourth promoter to transcribe mRNA encoding the major structural polypeptide, VP2. Analysis of the putative polypeptides confirms that B19 is only distantly related to the other parvoviruses but reveals that there is a small region in the gene probably encoding the major nonstructural protein of B19, which is closely conserved between all of the parvovirus genomes for which sequence information is currently available.

Nucleotide sequence and genome organization of human parvovirus B19 isolated from the serum of a child during aplastic crisis.

Objective: To determine the role of B19 parvovirus in red cell aplasia of patients infected with human immunodeficiency virus type 1 (HIV-1). Design: Uncontrolled clinical trial, with assay of seru...

Persistent B19 parvovirus infection in patients infected with human immunodeficiency virus type 1 (HIV-1): a treatable cause of anemia in AIDS.

The B19 parvovirus, which was serendipitously discovered in serum from blood-bank donors in 1975,1 has been associated with several human illnesses. B19 is the etiologic agent of the common childhood exanthem called fifth disease.2 Adults with fifth disease more commonly present with polyarthralgia than skin eruption, and B19 infection has frequently been detected in patients presenting with acute joint symptoms.3 , 4 In patients with underlying hemolysis, B19 infection is the cause of transient aplastic crisis, in which cessation of erythropoiesis leads to absolute reticulocytopenia and abrupt worsening of anemia.5 , 6 In utero infection with B19 has been associated with spontaneous abortion.7 8 9 Laboratory . . .

Chronic bone marrow failure due to persistent B19 parvovirus infection.

Human parvovirus is the causative agent of erythema infectiosum, a mild epidemic illness. In a recent outbreak in northeast Scotland, six women had serologic evidence of having contracted human parvovirus infection during pregnancy. Two of the women had midtrimester abortions, and both abortuses were grossly hydropic with anemia. They had similar microscopical histopathological features--a pronounced leukoerythroblastic reaction, hepatitis, excessive iron pigment in the liver, and eosinophilic changes in the hematopoietic cell nuclei. Dot hybridization with radiolabeled human parvovirus DNA probes revealed viral DNA in several tissues from both fetuses, indicating that they had been infected by the virus in utero. The remaining four women had uncomplicated pregnancies and delivered apparently healthy babies, none of whom had human parvovirus-specific IgM antibody at delivery. We conclude that this common virus may pose a serious risk to the fetus after maternal infection.

Human parvovirus infection in pregnancy and hydrops fetalis.

Human parvovirus-associated arthritis: a clinical and laboratory description

The hypothalamic-pituitary-adrenal (HPA) axis function of eight patients with rheumatoid arthritis receiving regular intra-articular methyl prednisolone acetate was studied. Tests of the HPA axis 5–7 weeks after the last injection revealed suppression in two patients. Some patients receiving intra-articular corticosteroids may therefore have abnormal responses to stress.

J. A. N. Rennie

Papers

Human parvovirus-associated arthritis: a clinical and laboratory description

Hypothalamic-pituitary-adrenal (HPA) axis function in patients receiving long-term intra-articular corticosteroids.