Primary dengue haemorrhagic fever in patients from northeast of Brazil is associated with high levels of interferon-β during acute phase

Dengue is an acute febrile disease caused by the mosquito-borne dengue virus (DENV) that according to clinical manifestations can be classified as asymptomatic, mild or severe dengue. Severe dengue cases have been associated with an unbalanced immune response characterised by an over secretion of inflammatory cytokines. In the present study we measured type I interferon (IFN-I) transcript and circulating levels in primary and secondary DENV infected patients. We observed that dengue fever (DF) and dengue haemorrhagic fever (DHF) patients express IFN-I differently. While DF and DHF patients express interferon-α similarly (52,71 ± 7,40 and 49,05 ± 7,70, respectively), IFN- β were associated with primary DHF patients. On the other hand, secondary DHF patients were not able to secrete large amounts of IFN- β which in turn may have influenced the high-level of viraemia. Our results suggest that, in patients from our cohort, infection by DENV serotype 3 elicits an innate response characterised by higher levels of IFN- β in the DHF patients with primary infection, which could contribute to control infection evidenced by the low-level of viraemia in these patients. The present findings may contribute to shed light in the role of innate immune response in dengue pathogenesis.

Initial Description of the Presumed Congenital Zika Syndrome.

OBJECTIVES: To provide an initial description of the congenital syndrome presumably associated with infection by Zika virus compared with other syndromes including congenital infections of established etiologies. METHODS: We provide an overview of a published case series of 35 cases, a clinical series of 104 cases, and published and unpublished reports of clinical and laboratory findings describing cases diagnosed since the beginning of the epidemic of microcephaly in Brazil. RESULTS: About 60% to 70% of mothers report rash during pregnancy; mainly in the first trimester. Principal features are microcephaly, facial disproportionality, cutis girata, hypertonia/spasticity, hyperreflexia, and irritability; abnormal neuroimages include calcifications, ventriculomegaly, and lissencephaly. Hearing and visual abnormalities may be present. CONCLUSIONS: Preliminary data suggest that severe congenital abnormalities are linked to Zika virus infection. Cases have severe abnormalities, and although sharing many characteristics with congenital abnormalities associated with other viral infections, abnormalities presumably linked to the Zika virus may have distinguishing characteristics. These severe neurologic abnormalities may result in marked mental retardation and motor disabilities for many surviving offspring. POLICY IMPLICATIONS: Affected nations need to prepare to provide complex and costly multidisciplinary care that children diagnosed with this new congenital syndrome will require.

Potential biomarkers for the clinical prognosis of severe dengue

Currently, several assays can confirm acute dengue infection at the point-of-care. However, none of these assays can predict the severity of the disease symptoms. A prognosis test that predicts the likelihood of a dengue patient to develop a severe form of the disease could permit more efficient patient triage and treatment. We hypothesise that mRNA expression of apoptosis and innate immune response-related genes will be differentially regulated during the early stages of dengue and might predict the clinical outcome. Aiming to identify biomarkers for dengue prognosis, we extracted mRNA from the peripheral blood mononuclear cells of mild and severe dengue patients during the febrile stage of the disease to measure the expression levels of selected genes by quantitative polymerase chain reaction. The selected candidate biomarkers were previously identified by our group as differentially expressed in microarray studies. We verified that the mRNA coding for CFD, MAGED1, PSMB9, PRDX4 and FCGR3B were differentially expressed between patients who developed clinical symptoms associated with the mild type of dengue and patients who showed clinical symptoms associated with severe dengue. We suggest that this gene expression panel could putatively serve as biomarkers for the clinical prognosis of dengue haemorrhagic fever.