title: False-negative serology in patients with acute parvovirus B19 infection.
abstract: BACKGROUND
  Acute parvovirus B19 (B19V) infection is characterized by high-level viremia. Antibodies against the capsid proteins VP1 and VP2 may complex with B19V-particles thereby becoming undetectable in diagnostic tests.
  
  
  OBJECTIVE
  We intended to obtain data on the frequency of false-negative serology in acute B19V-infection.
  
  
  METHODS
  129 plasma or serum samples of healthy blood donors and of patients with suspected B19V-infection were analyzed for B19V-DNA by qPCR and VP1/VP2-specific IgG and IgM by ELISA. Eleven of these samples were derived from four pregnant women with previous contact to B19V-infected individuals. Using acidic conditions virus/antibody-complexes were disrupted and detected by WesternLine and ELISA.
  
  
  RESULTS
  83/118 samples were derived from acutely infected individuals displaying viremia (10(3)-10(12)geq/mL). In 24/83 viremic samples (28.9%) VP1/VP2-specific IgM and IgG were undetectable in ELISA, but could be demonstrated to be complexed with B19V-particles. Each 7/83 (8.4%) was IgM-positive/IgG-negative and IgM-negative/IgG-positive, in 45/83 samples (54.2%) IgG and IgM could be detected. 35 samples did not contain B19V-DNA; five of these were from seronegative persons. Analyzing consecutive sera derived from four pregnant women, B19V-DNA was demonstrated in 10/11 samples, B19V-specific IgG- and IgM-antibodies were detectable in 10/11 and 4/11 samples, respectively. In 2/4 women seroconversion was observed, but IgM was not detected in 50% of the samples. B19V-specific IgG but not IgM was detectable in 2/4 women.
  
  
  CONCLUSIONS
  Acute B19V-infection cannot be diagnosed by exclusive analysis of B19V-specific antibodies. Only the combination of assays for detection of B19V-DNA and antibodies enables correct serodiagnosis.
authors.affiliation: Redbiotec AG, Wagistrasse 23, 8952 Schlieren Schwitzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Bredl
authors.forename: Annelie
authors.initials: A
authors.lastname: Plentz
authors.forename: Jürgen J
authors.initials: JJ
authors.lastname: Wenzel
authors.forename: Heiko
authors.initials: H
authors.lastname: Pfister
authors.forename: Johannes
authors.initials: J
authors.lastname: Möst
authors.forename: Susanne
authors.initials: S
authors.lastname: Modrow
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D004279:DNA, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D010322:Parvoviridae Infections / Q000175:diagnosis* / Q000821:virology; D016732:Parvovirus B19, Human / Q000276:immunology* / Q000302:isolation & purification*; D011247:Pregnancy; D012698:Serologic Tests
chemical_list: D000914:Antibodies, Viral; D004279:DNA, Viral; D007074:Immunoglobulin G