Eosinophilia during Hantavirus infection: a cohort study

BACKGROUND

There are emerging eosinophil-related considerations concerning viral infections. The role of eosinophils has poorly been evaluated during Hantavirus infection.

METHODS

The aim of this study was to determine the prevalence of eosinophilia (defined as an eosinophil count above 500 cells/mm³) during haemorrhagic fever with renal syndrome (HFRS) in a large cohort of patients, and to identify factors associated with eosinophilia.

RESULTS

Among 387 patients hospitalized for HFRS, 98 (25.3%) had eosinophilia. By univariate analysis, eosinophilia was significantly associated with more severe thrombocytopenia, high C-reactive protein level, white blood cell count and neutrophil count and lower nephrotoxic drug intake. As there was a collinearity between white blood cell count and C-reactive protein level, only C-reactive protein level with platelet count and nephrotoxic drug intake were entered in the multivariable analysis. Elevated C-reactive protein concentrations remained independently associated with eosinophilia.

CONCLUSION

Eosinophilia during HFRS affects one quarter of patients, and supports the role of eosinophils in antiviral immunity against hantavirus infection.

Cytokine, Chemokine, and Metalloprotease Activation in the Serum of Patients with Nephropathia Epidemica from the Republic of Tatarstan and the Republic of Mordovia, Russia

Nephropathia Epidemica (NE), endemic to several Volga regions of Russia, including the Republic of Tatarstan (RT) and the Republic of Mordovia (RM), is a mild form of hemorrhagic fever with renal syndrome caused by infection with rodent-borne orthohantaviruses. Although NE cases have been reported for decades, little is known about the hantavirus strains associated with human infection in these regions. There is also limited understanding of the pathogenesis of NE in the RT and the RM. To address these knowledge gaps, we conducted comparative analyses of patients with NE in the RT and the RM. Clinical symptoms were more severe in patients with NE from the RM with longer observed duration of fever symptoms and hospitalization. Analysis of patient sera showed changes in the levels of numerous cytokines, chemokines, and matrix metalloproteases (MMPs) in patients with NE from both the RT and the RM, suggesting leukocyte activation, extracellular matrix degradation, and leukocyte chemotaxis. Interestingly, levels of several cytokines were distinctly different between patients NE from the RT when compared with those from the RM. These differences were not related to the genetic variation of orthohantaviruses circulating in those regions, as sequence analysis showed that Puumala virus (PUUV) was the causative agent of NE in these regions. Additionally, only the “Russia” (RUS) genetic lineage of PUUV was detected in the serum samples of patients with NE from both the RT and the RM. We therefore conclude that differences in serum cytokine, chemokine, and MMP levels between the RT and the RM are related to environmental factors and lifestyle differences that influence individual immune responses to orthohantavirus infection.