Parvovirus B19 | One hundred IgM

General Information

Parvovirus B19 is a member of the Parvoviridae family. For reproduction, they need actively dividing cells, therefore, when entering the body, the virus resides and multiplies in the precursor cells of human erythrocytes - in the bone marrow. The risk of infecting cells increases with the degree of differentiation.

The cytotoxic effect of the B19 virus is manifested by the synthesis of unstructured proteins in the cell. Infected erythroblastic colonies contain large pronormoblasts with immature chromatin, cytoplasmic vacuolation, and large nuclei.

Observations on healthy volunteers revealed that the B19 virus causes a short, self-healing (in 4-8 days) delay in the production of erythrocytes. In people with a normal erythrocyte life cycle, this short delay does not cause anemia. But in patients whose erythropoietic (erythrocyte production) processes are accelerated due to bleeding, hemolytic or other types of anemia, an aplastic crisis may develop under the influence of the B19 virus. In immunosuppressed people, the virus persists – it stays in the body for a long time and causes chronic anemia.

Parvovirus infection is common in children. Infection can also develop in adults.

The virus is transmitted mainly by respiratory route. Direct transmission of infection is common in schools, public places and hospitals. Infection is also possible through transfusion of blood or blood products.

The clinical picture of the disease is diverse and depends on the immunological and hematological status of the host. In children with normal immune status, the virus causes infectious erythema - the so-called fifth disease of childhood. The manifestation of the disease begins with non-specific symptoms, which are often overlooked - fever, fever, rhinitis, nausea and diarrhea. In 5-7 days, a characteristic exanthema (rash) appears on the cheeks, which spreads to the whole body in a few days.

In healthy adults, the infection is asymptomatic in half of the cases. In other cases, the symptoms are flu-like. In women, the infection may be complicated by acute, symmetrical polyarthropathy, which is often mistaken for rheumatoid arthritis. Infectious phenomena last 1-3 weeks, although sometimes they last for months, which makes diagnostics even more difficult.

In people with hemolytic anemia and impaired erythropoiesis, the infection causes a temporary inhibition of erythrocyte production - a transient aplastic crisis.

In immunocompromised patients, viremia is manifested by chronic aplastic anemia, which is also accompanied by liver damage, respiratory disorders, and myocarditis.

During pregnancy, parvovirus infection is transferred to the fetus through the placenta (25% of cases). Since the life cycle of fetal erythrocytes is short before 20 weeks of gestation and the immune response cannot develop, there is a risk of severe anemia and premature termination of pregnancy.

Parvovirus infection in the second trimester causes fetal ascites, which ends in the death of the fetus.

IgM antibodies develop in 10-12 days after exposure, while IgG antibodies take about 2 weeks to develop.

IgM antibodies remain in the blood for several months after infection. IgG remains throughout life and its titer increases in case of re-infection.

The development of chronic parvovirus infection is the result of immunosuppression, when the immune system cannot produce enough antibodies.

When is the survey conducted?

Diagnosis of newly acquired parvovirus infection

Assessment of immunity to parvovirus

Preparation of the patient: The study does not require prior preparation of the patient.

Material for examination: Venous blood

Referral norms:

Parvovirus IgG: negative

Parvovirus IgM: negative

Interpretation of results

Negative results of antibody determination do not exclude parvovirus infection. A false-negative result is common in the early stages of the disease, before the appearance of antibodies.

In immunosuppressed patients, interpretation of test results is often difficult.

A false positive result of IgM antibodies can be caused by Epstein-Barr virus.

The diagnostics of prolonged parvovirus infection should not be based only on serological data, but also requires a PCR study and the detection of virus DNA in the blood.