Download PDF

Assay Sheet

Test ID

1500 Parvovirus B19 Real-time qPCR

CPT Code

87799 

Clinical Utility

Parvovirus B19 manifests itself as an acute or chronic hematological disorder in immunocompromised patients. It can cause persistent anemia, sometimes associated with leukopenia and thrombocytopenia. Pediatric transplant patients are at risk for chronic infections, which can be associated with lung and/or renal disorders. Quantitative DNA PCR can be used to detect the presence of the virus, track the course of infection, and monitor response to treatment.

Procedure

Extraction of parvovirus B19 viral DNA from plasma, bone marrow, biological fluids, or tissues; amplification and detection using real-time, quantitative PCR. An internal control is added to ensure the extraction was performed correctly and the PCR reaction was not inhibited. ViraCor’s assay design includes multiple-gene targets to account for viral mutations, which exponentially reduces the chance of false negative results.

Specimen type & specimen handling

Whole Blood: 4-5 mls collected in EDTA (lavender top) tube. Do not freeze; ship ambient. Testing will be performed on plasma separated from the submitted whole blood specimen. Whole blood specimens are accepted as a matter of convenience for the originating laboratory. 

Plasma: Collect 4-5 mls whole blood in EDTA or ACD tube, centrifuge and transfer 2 mls plasma to sterile, screw top tube. Ship at ambient temperature Monday thru Friday. Specimen must be received within 96 hrs of collection.

Amniotic Fluid: 2 mls collected in a sterile, screw top tube. Ship at ambient temperature Monday thru Friday. Specimen must be received within 96 hrs of collection.

Bone Marrow: 2 mls collected in EDTA tube. Ship at ambient temperature Monday thru Friday. Do not centrifuge or freeze. Specimen must be received within 96 hrs of collection.

Tissue: Place in sterile, screw top container; add small amount of sterile saline to keep moist. Paraffin embedded tissue is acceptable.  Ship at ambient temperature Monday thru Friday.  Fresh tissue must arrive within 96 hrs of collection.

Call ViraCor for authorization prior to sending any specimen type other than those listed above.  

If another specimen type has received authorization for testing the following comment will appear in the final report: "The clinical utility of this result has not yet been demonstrated in the peer reviewed literature and is therefore unknown."

Causes for rejection

Whole blood frozen

Call ViraCor at 800-305-5198 if specimen is greater than 96 hrs old

Specimen types other than those listed above that were sent without prior authorization

Specificity

The primers and probes used in this assay are specific for parvovirus B19 based on similarity search algorithms. Additionally, no cross reactivity was detected when tested against adenoviruses, BKV, CMV, EBV, HSV-1, HSV-2, HHV-6 variant A, HHV-6 variant B, HHV-7, HHV-8, JCV, SV-40, and VZV.

Parvovirus B19 Assay Range

100 copies/ml to 1 x 10¹⁰ copies/ml

Tissue specimen results will be normalized to copies/1,000 cells  

Turnaround Time

Same day (within 8 to 12 hours of receiving specimen), Monday through Saturday

Shipping

ViraCor Laboratories, 1001 NW Technology Dr, Lee's Summit, MO 64086

The CPT codes provided are based on ViraCor’s interpretation of the American Medical Association’s Current Procedural Terminology (CPT) codes and are provided for informational purposes only. CPT coding is the sole responsibility of the billing party. Questions regarding coding should be addressed to your local Medicare carrier. ViraCor assumes no responsibility for billing errors due to reliance on the CPT codes illustrated in this material. PCR tests are performed pursuant to a license agreement with Roche Molecular Systems, Inc. This assay was developed and the performance characteristics were determined at ViraCor Laboratories. This test is performed in a CLIA certified laboratory. FDA approval is not required for the performance of this test.

0909 V2

Pathogen Overview

ABOUT VIRUS PARVOVIRUS B19

Parvovirus B19 (ParvoB19) is a nonenveloped, single-stranded DNA virus. It was discovered in 1974 and is currently the only member of the Parvoviridae family known to be pathogenic to humans. ParvoB19 is a major causative agent of transient aplastic crisis and erythema infectiosum, as well as an acute infection that causes an adult arthritis syndrome, hydrops fetalis in fetuses and chronic anemia in immunocompromised patients.

PARVOVIRUS B19 CLINICAL MANIFESTATIONS

ParvoB19 infections occur commonly throughout the globe; although infections can occur at any age, they are most frequently seen in children of school age. The prevalence of infection is 2 to 15% in children 1 to 5 years of age, 15 to 60% for those 5 to 9 years and approximately 60% for adults. Over 90% of the geriatric population has detectable ParvoB19 antibodies. ParvoB19 is transmitted through respiratory secretions, contaminated blood products, nosocomial infections, and vertical transmission from mother to fetus.

A primary infection, lasting approximately 1 week, usually involves mild and nonspecific symptoms, such as fever, malaise, and headache. In children, erythema infectiosum, also known as the fifth disease or slapped cheek disease, is commonly seen. A rash on the arms, legs, and trunk can develop within a few days, accompanied by mild to moderate pruritis in up to 70% of cases. In adults, especially women, arthralgia and arthritis are the most common symptoms seen in community outbreaks. One of the most serious complications of ParvoB19 is transient aplastic crisis (TAC), which is seen in patients with chronic hemolytic anemias. The symptoms of TAC are typically secondary to the acute viremia and serious anemia caused by ParvoB19.

ParvoB19 causes pure red cell aplasia and anemia in bone marrow and solid organ transplant recipients. Because anemia is a common problem after transplantation, it is important to determine whether the cause is due to another clinical condition, such as GI bleeding, iron deficiency, hemolysis, or drug toxicity, instead of a virus, such as ParvoB19. The virus has been shown to cause chronic anemia in renal transplant patients, HIV patients, and hematopoietic stem cell transplant (HSCT) patients with graft-versus-host disease. A ParvoB19 infection should be strongly suspected any time a renal transplant patient develops anemia (in the presence of normal renal function) and resistance to erythropoietin therapy. In some cases, chronic ParvoB19 infections have been associated with congenital immunodeficiency syndrome, AIDS, and immunosuppression induced during chemotherapy.

PARVOVIRUS B19 LABORATORY DIAGNOSIS

Diagnosis of a primary ParvoB19 infection typically relies on the detection of IgM and/or IgG antibodies or viral DNA. In immunocompromised patients, serological forms of diagnosis are inadequate since these patients are often unable to mount an adequate immune response. Additionally, serological methods are not useful in diagnosing a low grade chronic infection of the virus. Since it is important to rapidly identify the cause of anemia in transplant patients in order to begin treatment as soon as possible, a more sensitive and reliable method of diagnosis is required. Real-time, quantitative polymerase chain reaction (PCR) is the preferred method for an accurate diagnosis in these patients. Real-time, quantitative PCR is sensitive and allows an accurate measure of the viral burden (viral load) in the patient, thereby enabling the physician to monitor the infection and track the response to therapy over time.

PARVOVIRUS B19 TREATMENT

Currently, there is no specific antiviral drug for ParvoB19. Patients with TAC can often benefit from blood transfusions. Immunocompromised patients can be helped by a reduction of immunosuppressive therapy and, in some cases, by the administration of IV immunoglobulin (IVIG). Both low dose IVIG (0.25 g/kg/for 3 days) and high dose IVIG (0.5 g/kg for 5 days) have been used, depending upon patient response.

Selected References

Bertoni E, Rosati A, Zanazzi M, Azzi A, Zakrzewska, K, et al. Aplastic anemia due to B19 parvovirus infection in cadaveric renal transplant recipients: an underestimated infectious disease in the immunocompromised host. J Nephrol. 1997;(10):152-156.

Gallinella G, Manaresi E, Venturoli S, Grazi GL, Musiani M, et al. Occurrence and clinical role of active parvovirus B19 infection in transplant recipients. Eur J Clin Microbiol Infect Dis. 1999;(18):811-813.

Knipe D, Howley P. Fields Virology. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006.
Liefeldt L, Buhl M, Schweikert B, Englemann E, Sezer O, Laschinski P, et al. Eradication of parvovirus B19 infection after renal transplantation requires reduction of immunosuppression and high-dose immunoglobulin therapy. Nephrol Dial Transplant. 2002;(17):1840-1842.

Pamidi S, Friedman K, Kampalath B, Eshoa C, Hariharan S. Human parvovirus B19 infection presenting as persistent anemia in renal transplant recipients. Transplantation. 2000;(69):2666-2669.

Portmore AC. Parvoviruses (erythema infectiosum, aplasatic crisis). In: Mandell GL, Bennett JE, Dolin, eds. Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases. Vol 2. 4th ed. New York, NY: Churchill Livingstone; 1995:1439-1446.

Zolnourian ZR, Currin MD, Rima BK, Coyle PV, O’Neill HJ, et al. Parvovirus B19 in kidney transplant patients. Transplantation.
2000;(69):2198-2201.

PAO-12-0707 PCR tests are performed pursuant to a license agreement with Roche Molecular Systems, Inc.

Abstracts & Publications

Bertoni E, Rosati A, Zanazzi M, et al. Aplastic anemia due to B19 parvovirus infection in cadaveric renal transplant recipients: an underestimated infectious disease in the immunocompromised host. J Nephrol. 1997;(10):152-156.

Parvovirus B19 has been identified as the etiological agent of "fifth disease" in childhood. It is also a rarely reported cause of anemia in transplanted patients. During a period of 18 months, we observed four cases (2 male and 2 female; 53 + 4.24 years) of severe aplastic anemia due to parvovirus B19 in kidney transplant patients. The overall incidence of the disease was 6.3% of all our transplanted patients. Symptoms of the disease occurred 22.5 + 9.75 days post-operatively. Serum creatinine was 1.5 + 0.35 mg/dL. Hb was 6.58 + 0.6 g/dL. All patients recovered within 15 days of high doses of commercial immunoglobulins. We conclude that B19 parvovirus infection is probably an underestimated disease in transplant patients. It is a first-period infection, probably donor-transmitted. High dose immunoglobulins are an effective but costly therapy.

Gallinella G, Manaresi E, Venturoli S, et al. Occurrence and clinical role of active parvovirus B19 infection in transplant recipients. Eur J Clin Microbiol Infect Dis. 1999;(18):811-813.

To evaluate the occurrence of active parvovirus B19 infection in solid organ and bone marrow transplant recipients. 256 serum samples from 212 transplant patients were investigated retrospectively by comparative polymerase chain reaction. Sera were drawn during the transplantation period and up to 6 months after transplantation during a nonepidemic 1-year period. Three patients were found positive for B19 DNA; only one liver transplant patient had a clinically overt B19 infection. Overall, the rate of active parvovirus B19 infection in transplant subjects was low (1.42%), probably due to the high number of actively or passively immunized subjects among transplant recipients; this may also account for the asymptomatic infections observed.

Liefeldt L, Buhl M, Schweikert B, et al. Eradication of parvovirus B19 infection after renal transplantation requires reduction of immunosuppression and high-dose immunoglobulin therapy. Nephrol Dial Transplant. 2002;(17):1840-1842.

Anaemia is a frequent problem after renal transplantation, which may appear as hypo-regenerative anemia (due to myelotoxic drugs or infectious agents and/or poor graft function) of hyper-regenerative anemia (haemolysis or bleeding). It, therefore, seems reasonable to distinguish between different underlying causes of anemia according to reticulocyte counts. One of the presumably rather rare infectious agents causing transient hypo-regenerative anaemia is the human parvovirus B19 (HPV B19) that was discovered in human blood 25 years ago and was found to be the cause of "fifth disease" in children in the 1980s.More recently, it became evident that this virus may also cause severe infections in immunocompromised adults. Here, we report on virological monitoring and on attempts to eradicate HPV B19 in a renal transplant recipient suffering from pure red cell anaemia as a severe form of hypo-regenerative anaemia. Furthermore, we systematically review the literature with respect to treatment regimens.

Pamidi S, Friedman K, Kampalath B, Eshoa C, Hariharan S. Human parvovirus B19 infection presenting as persistent anemia in renal transplant recipients. Transplantation. 2000;(69):2666-2669.

BACKGROUND: Immunosuppression cannot be achieved without immunosuppressive effects. Human Parvovirus infection is known to occur after organ transplantation. We present our experience with Parvovirus infection in two cases.
METHODS AND RESULTS: Two kidney transplant recipients developed symptomatic anemia requiring blood transfusions. Common causes of anemia, such as gastrointestinal bleeding, iron/vitamin deficiencies, hemolysis, and drug toxicities, were ruled out. A peripheral smear revealed low reticulocyte count. Bone marrow examination showed hypoplastic bone marrow with intranuclear inclusions suggestive of human Parvovirus. This was confirmed by immunohistochemical analysis. Treatment with i.v. immunoglobulin G resulted in a dramatic sustained response. Transplant kidney function remained stable.
CONCLUSION: Human Parvovirus infections should be considered in immunosuppressed individuals with anemia with poor bone marrow response. Bone marrow examination can reveal viral inclusions and can be confirmed by immunohistochemical analysis. Intravenous immunoglobulin G results in resolution of anemia.

Zolnourian ZR, Currin MD, Rima BK, et al. Parvovirus B19 in kidney transplant patients. Transplantation. 2000;(69):2198-2201.

Renal transplant patients were screened for the presence of parvovirus B19, before transplantation and monthly for 4 months after transplantation, by means of a sensitive nested PCR assay. Upon screening plasma from 110 patients, we found that two asymptomatic patients were B19 DNA positive. One of these patients was PCR positive in the plasma sample taken 2 months after transplantation; the plasma contained anti-B19 IgG antibodies before transplant and throughout the follow-up period, with an increase in the IgG level in the second posttransplant sample coinciding with the detection of B19 DNA. IgM antibodies to B19 were not detected in this patient. Because, for this patient, the donor's spleen DNA was also B19 DNA positive, we suspect B19 transmission from the donor and limited B19 replication, inasmuch as this patient already had primed immune response to B19. The other patient was PCR positive in the pretransplant and in the plasma sample taken 1 month after transplant and contained a strong anti-B19 IgG response in the pretransplant sample and throughout the follow-up period-and anti-B19 IgM antibodies were not detected before or after transplantation. By testing samples taken from this patient at 2 weeks, 2 months, and 3 months before transplantation, we were able to determine that the infection occurred shortly before transplantation. Unexpectedly, this graft failed and was removed 2 days after transplantation despite a negative cross-match. A pathological examination of the kidney indicated acute vascular rejection, suggesting a possible role for B19 in this complication.