Histopathological and immunological characteristics of placentas infected with chikungunya virus

Abstract

Although vertical transmission of CHIKV has been reported, little is known about the role of placenta in the transmission of this virus and the effects of infection on the maternal-fetal interface. In this work we investigated five placentas from pregnant women who became infected during the gestational period. Four formalin-fixed paraffin-embedded samples of placenta (cases 1–4) were positive for CHIKV by RT-PCR. One (case 5) had no positive test of placenta, but had positive RT-PCR for CHIKV in the serum of the mother and the baby, confirming vertical transmission. The placentas were analyzed regarding histopathological and immunological aspects. The main histopathological changes were: deciduitis, villous edema, deposits, villous necrosis, dystrophic calcification, thrombosis and stem vessel obliteration. In infected placentas we noted increase of cells (CD8+ and CD163+) and pro- (IFN-γ and TNF-α) and anti-inflammatory (TGF-β and IL-10) cytokines compared to control placentas. Moreover, CHIKV antigen was detected in decidual cell, trophoblastic cells, stroma villi, Hofbauer cells, and endothelial cells. In conclusion, CHIKV infection seems to disrupt placental homeostasis leading to histopathological alterations in addition to increase in cellularity and cytokines overproduction, evidencing an altered and harmful environment to the pregnant woman and fetus.

The Innate Immune Response in DENV- and CHIKV-Infected Placentas and the Consequences for the Fetuses: A Minireview

“…Vertical transmission of the dengue and chikungunya viruses has already been shown in previous studies [33,77,114,134,138,150]. However, little is known about the intrinsic mechanisms and cells involved in this event.…”

Collateral Damage in the Placenta during Viral Infection in Pregnancy: A Possible Mechanism for Vertical Transmission and an Adverse Pregnancy Outcome

“…Viruses such as Chikunguya, which have not been associated with vertical transmission, have been shown to infect placental cells such as trophoblasts and decidual, stromal, Hofbauer, and endothelial cells. This infection promotes an overexpression of proinflammatory elements associated with the development of severe damage in the placental tissue, causing inflammation in the decidua, villous edema, villous necrosis, dystrophic calcification and thrombosis, which culminate in alterations in placental homeostasis and promote histopathological alterations, evidencing a harmful environment for the fetus and the mother [ 16 ]. It is believed that the infection of the placenta by this virus occurs through a microtransfusion of maternal blood and the subsequent rupture of the membrane of syncytiotrophoblasts due to uterine contractions [ 153 , 154 ].…”

“…This pathological manifestation can functionally and structurally disrupt the physiological barrier, culminating in complications ranging from abortion, premature birth, fetal growth restriction, the premature rupture of membranes and fetal and maternal death. In this review, we aimed to capture evidence related to the effects of some viruses on the generation of pathological disturbances in the placenta, following the idea that not all viral infections can be transmitted vertically but maternal infection can collaterally damage the architecture of the placental barrier, culminating in adverse perinatal outcomes [ 15 , 16 ].…”

Congenital Chikungunya Virus Infections

“…The CHIKV RNA and antigens can be detected in the placental tissue seen as histopathological (deciduitis, fibrin deposition, edema, fetal vessel thickening, and chorioamnionitis) and ultrastructural alterations (cytotrophoblast with mitochondrial swelling and dilated cisterns in the endoplasmic reticulum, vesicles in syncytiotrophoblasts, and thickening of the basement membrane of the endothelium). 145,146 Table 3 presents the case definitions of neonatal chikungunya.…”