Elevated plasma surfactant protein D (SP-D) levels and a direct correlation with anti-severe acute respiratory syndrome coronavirus-specific IgG antibody in SARS patients.

Abstract

Pulmonary SP-D is a defence lectin promoting clearance of viral infections. SP-D is recognized to bind the S protein of SARS-CoV and enhance phagocytosis. Moreover, systemic SP-D is widely used as a biomarker of alveolar integrity. We investigated the relation between plasma SP-D, SARS-type pneumonia and the SARS-specific IgG response. Sixteen patients with SARS, 19 patients with community-acquired pneumonia (CAP) (Streptococcus pneumonia) and 16 healthy control subjects were enrolled in the study. Plasma SP-D and anti-SARS-CoV N protein IgG were measured using ELISA. SP-D was significantly elevated in SARS-type pneumonia [median (95% CI), 453 (379-963) ng/ml versus controls 218 (160-362) ng/ml, P < 0.05] like in patients with CAP. SP-D significantly correlated with anti-SARS-CoV N protein IgG (r(2) = 0.5995, P = 0.02). The possible re-emergence of SARS or SARS-like infections suggests a need for minimal traumatic techniques for following the alveolar compartment, e.g. during testing of antivirals. We suggest that monitoring systemic SP-D may be useful in monitoring the alveolar integrity in SARS-type pneumonia. The significant correlation between plasma SP-D and anti-SARS-CoV-specific antibodies support the role for SP-D in interlinking innate and adaptive immune pathways.

• Authors: Y P Wu, Z H Liu, R Wei, S D Pan, N Y Mao, B Chen, J J Han, F S Zhang, U Holmskov, Z L Xia, P G de Groot, K B M Reid, W B Xu, G L Sorensen
• Journal: Scandinavian journal of immunology (Scand J Immunol) Vol. 69 Issue 6 Pg. 508-15 (Jun 2009) ISSN: 1365-3083 [Electronic] England
• PMID: 19439011 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Viral
• Biomarkers
• Coronavirus Nucleocapsid Proteins
• Immunoglobulin G
• Nucleocapsid Proteins
• Pulmonary Surfactant-Associated Protein D
• Recombinant Proteins

Topics

• Adolescent
• Adult
• Aged
• Antibodies, Viral (blood)
• Biomarkers (blood)
• Child
• Child, Preschool
• Coronavirus Nucleocapsid Proteins
• Enzyme-Linked Immunosorbent Assay
• Female
• Humans
• Immunoglobulin G (blood)
• Male
• Middle Aged
• Nucleocapsid Proteins (immunology)
• Pulmonary Surfactant-Associated Protein D (blood)
• Recombinant Proteins (immunology)
• Reverse Transcriptase Polymerase Chain Reaction
• Severe acute respiratory syndrome-related coronavirus (immunology)
• Severe Acute Respiratory Syndrome (immunology)