Page 115 - TBE_Book_V2_2019

Chapter 5: TBE in adults

patterns (PAMPs), cell migration, and Clinical course
interaction with T lymphocytes, potentially
contributing to an early response to TBEV at
the site of tick feeding and initiation of a Pathogenesis – preclinic phase
specific immune response. It is coded by
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CD209 gene on the chromosome. Findings in After a tick bite, the released TBEV in the skin
the context of dengue virus and HCV replicates subcutaneously and is, in this early
infections pointed to an increased risk of stage, limited to the skin. Dendritic cells of the
dengue hemorrhagic fever and advanced skin, the Langerhans cells, bind with antigens
hepatic injury in hepatitis C when there is an and subsequently induce an immune response
underlying SNP (rs4804803) located in the by producing proinflammatory cytokines.
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promoter region of the CD209 gene. After the initial replication in the skin, TBEV
Dendritic cells in the skin and gut probably replicates in the lymph nodes and lymphatic
play an important role in the early stages of system, leading to viremia. DCs and
TBEV infection. These antigen-presenting cells macrophages are crucially involved in TBEV
act as a source of pro-inflammatory and replication, and may contribute to the spread
antiviral mediators and as initiators of a to uninfected cells, thereby serving as an
specific immune response. However, this cell important source of local virus replication
type is susceptible to TBEV as well and before viremia occurs. 35,36
facilitates the initial spread of TBEV from the
primary site of infection to remote regions of Photo 1.
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the mammalian host. A clinical study from
Russia enrolling 136 non-vaccinated TBE
patients showed a correlation between the
presence of 2 SNPs (rs4804803, rs2287886) in
the promotor region of the CD209 gene and
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severity of TBE disease course. The studied
patient population was stratified into different
clinical syndromes–isolated febrile illness
(n=35), meningitis (n=61), and severe CNS
manifestation such as meningoencephalitis
(n=40). The control group comprised 263
healthy individuals from the same Siberian
region. The Russian TBE cases were
presumably infected with the TBEV- Sib.
However, it should be noted that, to date,
there has been no study investigating CD209
polymorphisms in European TBE patients
infected with the western subtype of TBEV.

Bilateral flaccid paralysis of the arms, shoulders,
and the levator muscles of the head.

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