Expression of Surfactant Protein D Distinguishes Severe Pandemic Influenza A(H1N1) from Coronavirus Disease 2019
José Alberto Choreño-Parra, Luis Jiménez-Álvarez, Gustavo Ramírez-Martínez, Alfredo Cruz‐Lagunas, Mahima Thapa, Luis Alejandro Fernández-López, Martha Carnalla, Eduardo M. Choreño‐Parra, Lourdes Mena‐Hernández, Montserrat Sandoval-Vega, Erika Mariana Hernández-Montiel, Diana Lizzeth Hernández-García, Jazmín Ariadna Ramírez-Noyola, Cynthia Estefania Reyes-López, Andrea Domínguez-Faure, Guillermo Yamil Zamudio-López, Eduardo Márquez-García, Angélica Moncada-Morales, Criselda Mendoza-Milla, Diana Cervántes-Rosete, Marcela Muñóz-Torrico, César Luna-Rivero, Ethel Garcı́a-Latorre, Parménides Guadarrama-Ortíz, Federico Ávila‐Moreno, Guillermo Domínguez‐Cherit, Tatiana Sofia Rodrı́guez-Reyna, Philip A. Mudd, Carmen Margarita Hernández‐Cardenas, Shabaana A. Khader, Joaquı́n Zúñiga
Abstract
The differentiation between influenza and coronavirus disease 2019 (COVID-19) could constitute a diagnostic challenge during the ongoing winter owing to their clinical similitude. Thus, novel biomarkers are required to enable making this distinction. Here, we evaluated whether the surfactant protein D (SP-D), a collectin produced at the alveolar epithelium with known immune properties, was useful to differentiate pandemic influenza A(H1N1) from COVID-19 in critically ill patients. Our results revealed high serum SP-D levels in patients with severe pandemic influenza but not those with COVID-19. This finding was validated in a separate cohort of mechanically ventilated patients with COVID-19 who also showed low plasma SP-D levels. However, plasma SP-D levels did not distinguish seasonal influenza from COVID-19 in mild-to-moderate disease. Finally, we found that high serum SP-D levels were associated with death and renal failure among severe pandemic influenza cases. Thus, our studies have identified SP-D as a unique biomarker expressed during severe pandemic influenza but not COVID-19.