Quantitation of antibody-bound and unbound Sin Nombre virus in the plasma of patient with hantavirus pulmonary syndrome

UMMS Affiliation

Center for Infectious Disease and Vaccine Research; Department of Medicine, Division of Infectious Diseases and Immunology

Publication Date


Document Type



Immunity | Immunology and Infectious Disease | Immunology of Infectious Disease | Infectious Disease | Virology


Hantavirus pulmonary syndrome (HPS) is a rare but acute fulminant disease caused by Sin Nombre virus and other related hantaviruses. We reported earlier that HPS patients had high levels of viremia and the levels of viremia correlated with the severity of the disease. To determine whether the viruses are free in plasma or bound to antibodies to form immune complexes, we established a method to quantitate viral genomic RNA in antibody-bound viruses and in unbound viruses separately. To isolate immune complexes from plasma we used protein L, which binds to all classes of immunoglobulins and all subclasses of IgG, and we measured viral RNA copy number in antibody-bound viruses and unbound viruses by quantitative RT-PCR. We analyzed plasma samples collected on admission from 15 patients with HPS in the acute phase. The percentage of viral RNA in immune complexes versus total viral RNA varied from 9 to 91% among patients, and correlated with the total viral RNA copy numbers (P < 0.05) and the neutralizing antibody titers of plasma (P < 0.05). This quantitative method may be useful to examine diseases where immune complex formation or antibody-dependent enhancement may be involved in pathogenesis.

DOI of Published Version



J Virol Methods. 2003 Jun 30;110(2):159-62. doi:10.1016/S0166-0934(03)00124-1

Journal/Book/Conference Title

Journal of virological methods

Related Resources

Link to Article in PubMed

PubMed ID