3121. PCR. Parvovirus B19 (blood, quantification)

Parvovirus B19 PCR testing in blood is an accurate method for detecting and quantifying the pathogen's DNA. It is used in cases of suspected acute infection, intrauterine transmission, unexplained anemia, and in immunocompromised patients.

Parvovirus B19 is a small DNA virus of the Parvoviridae family that has a pronounced affinity for erythroid progenitor cells in the bone marrow. Infection with this virus results in a temporary cessation of erythropoiesis. In healthy individuals, this typically has no clinical consequences, but in certain patient groups it can cause dangerous complications, including:

• Aplastic crises in chronic hemolytic anemias (thalassemia, sickle cell anemia).
• Chronic anemia in immunosuppressed individuals (HIV, transplantation, chemotherapy).
• Intrauterine infection of the fetus, which can lead to non-immune hydrops fetalis, anemia, or fetal death, especially if infection occurs before the 20th week of pregnancy.

PCR (polymerase chain reaction) in blood is a highly sensitive molecular diagnostic method that detects Parvovirus B19 DNA directly in blood plasma, even before the onset of clinical manifestations or serological response.

Quantitative determination allows for:

• Assessment of viremia (viral load).
• Confirmation of active infection.
• Monitoring the effectiveness of treatment or spontaneous clearance of the virus.
• Objectively assessing the risk of vertical transmission of the virus to the fetus during pregnancy.
• Monitoring the chronic course of infection in immunocompromised patients.

Unlike IgM/IgG tests, PCR is independent of the body's immune response. This is critically important in:

• Immunosuppression, when antibodies are not produced or appear late.
• Virus persistence in bone marrow or blood.
• Assessment of infection in newborns and in cases of intrauterine infection.

Additionally:

• In cases of acute infection in pregnant women, PCR is used to quantify viremia and guide pregnancy management.
• Low DNA titers after the acute phase can persist in the blood for weeks, and in some cases, months.
• PCR is used as the gold standard in cases where serological results are inconsistent or insufficiently informative.

Parvovirus B19 PCR (quantitative) is a clinically relevant test that provides early diagnosis, objective confirmation of active infection, and monitoring of important clinical scenarios, particularly in hematology, neonatology, reproductive medicine, and immunology.

• Pregnant women with a positive IgM or suspected intrauterine infection – to assess viremia and the risk of fetal damage (hydrops, anemia).
• Patients with anemia of unknown origin, especially in those with concomitant immunodeficiency or chronic hemolytic anemia.
• Immunosuppressed patients (cancer, HIV, transplantation), in whom serology may be unreliable.
• Newborns and infants with manifestations of congenital infection, developmental delay, or hepatosplenomegaly.
• To monitor viral load in patients with prolonged or chronic infection.

• Venous blood

In order to exclude factors that may affect the test results, we recommend to follow the preparation rules: