Comparison of two automated immunoassays for the determination of Puumalavirus IgM and IgG.
BACKGROUND
Puumala virus (PUUV), a member of the genus hantavirus, can cause nephropathia epidemica, a mild form of haemorrhagic fever with renal syndrome. The method of choice for the serodiagnosis of hantavirus infections are enzyme-linked immunosorbent assays (ELISAs).


OBJECTIVE
Two commercially available PUUV ELISA kits were compared: Hantavirus (Puumala) IgM/IgG ELISA (Progen, Heidelberg, Germany) and PUUMALA IgM and IgG EIA AutoM (Reagena, Toivala, Finland).


METHODS
The sensitivity of the ELISA kits was evaluated with a panel of 55 serum samples from patients with an acute (n=27) or past (n=28) infection based on Progen or Reagena. A panel of 56 serum samples was composed to evaluate the specificity: samples with potentially false positive Progen Puumala IgM results (n=12), seronegative samples for Puumala IgG/IgM with Progen (n=20), and potentially cross reacting samples (n=24). Discrepancies between the two assays were resolved with strip immunoblot. As measure of agreement between Progen and Reagena results, Cohen kappa coefficient was calculated.


RESULTS
Reagena showed a higher specificity (IgM 100%, IgG 100%) than Progen Puumala (IgM 73.21%, IgG 100%). However, Reagena showed a slightly lower sensitivity (IgM 96.15%, IgG 97.78%) compared with Progen (IgM 100%, IgG 100%). Substantial agreement with a Cohen kappa of 0.67 and 0.76 was found between the two assays for Puumala IgM and IgG respectively.


CONCLUSIONS
This study showed a higher specificity of Reagena in comparison to Progen with a lower sensitivity, probably caused by selection bias. In spite of Reagena's lower sensitivity, no acute infection was missed with this assay.
National Reference Center for Hantavirus, Department of Laboratory Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium. Electronic address: astrid.muyldermans@student.kuleuven.be.
Astrid
A
Muyldermans
National Reference Center for Hantavirus, Department of Laboratory Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
Katrien
K
Lagrou
National Reference Center for Hantavirus, Department of Laboratory Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
Sofie
S
Patteet
Institute of Tropical Medicine Antwerp, Kronenburgstraat 43/3, 2000 Antwerp, Belgium.
Marjan
M
Van Esbroeck
National Reference Center for Hantavirus, Department of Laboratory Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
Marc
M
Van Ranst
National Reference Center for Hantavirus, Department of Laboratory Medicine, University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium.
Veroniek
V
Saegeman
D000914:Antibodies, Viral / Q000097:blood*; D057205:Automation, Laboratory / Q000379:methods*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006480:Hemorrhagic Fever with Renal Syndrome / Q000175:diagnosis*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D029262:Puumala virus / Q000276:immunology*; D012680:Sensitivity and Specificity
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M
ELISA; Hantaviruses; Nephropathia epidemica; Puumalavirus; Sensitivity; Specificity