Table 2.

Principal serum markers and their clinical impact in diagnosis and management of HAdV infections in children and young adults. CRP = C reactive protein, HAdV = human adenovirus, URTIs = upper respiratory tract infections, humans. Between general infection sites and HAdV species. Other HAdV species may also occur at the site of infection, T CD4+ = T helper, T reg = T regulatory, IL = interleukin, TNF = tumor necrosis factor, IFN = interferon.

Marker	Advantages	Disadvantages	Limitations
CRP/procalcitonin	Early rise in serum in acute infections	May not differentiate HAdV and bacterial infections	Potential application in URTIs
White Blood Cells	Elevated in the acute HAdV infections	May not differentiate viral and bacterial infections	Observed only in some species [69]
Neutrophils	Elevated in HAdV rather than other viral infections	Typical also of bacterial infections	May not be suitable in older patients
Monocytes	Elevated in URTIs, prognostic significance	Not exclusive marker for HAdV	Prognostic value studied only in young adults
T CD4+	Elevated in URTIs and silent HAdV infections	-	Observed in some types, Not routinely assessed
T reg	-	-	Few and conflicting data, Not routinely assessed
IL-10	Early rise in serum in acute infections, prognostic significance	May not differentiate viral and bacterial infections [70]	Prognostic significance evaluated only in severe infections
IL-6	Elevated in HAdV rather than other viral infections, prognostic significance, may be assessed in nasal swabs	May not differentiate HAdV and bacterial infections	-
IL-8	Prognostic significance in children, may be assessed in nasal swabs, more stable along the disease course	Loss of prognostic value in young adults	-
IL-1β and TNF-α	-	Not exclusive marker for HAdV	Unclear course in HAdV infection
IFN-γ	Elevated in the acute HAdV infections	Not exclusive marker for HAdV in children	Prognostic value evaluated only in severe infections in young adults