Liver immunopathogenesis in fatal cases of dengue in children: detection of viral antigen, cytokine profile and inflammatory mediators.

Introduction: Dengue virus (DENV), the etiologic agent of dengue fever illness, represents a global public health concern, mainly in tropical and subtropical areas across the globe. It is well known that this acute viral disease can progress to severe hemorrhagic stages in some individuals, however, the immunopathogenic basis of the development of more severe forms by these patients is yet to be fully understood. Objective: In this context, we investigated and characterized the histopathological features as well as the cytokine profile and cell subpopulations present in liver tissues from three fatal cases of DENV in children. Methods: Hematoxylin and Eosin, Periodic Acid Schiff and Picro Sirius Red staining were utilized for the histopathological analysis. Immunohistochemistry assay was performed to characterize the inflammatory response and cell expression patterns. Results: Vascular dysfunctions such as hemorrhage, vascular congestion and edema associated with a mononuclear infiltrate were observedin all three cases. Liver tissues exhibited increased presence of CD68+ and TCD8+ cells as well as high expression of MMP-9, TNF-a, RANTES, VEGFR-2 mediators. Viral replication was confirmed by the detection of NS3 protein. Conclusion: Taken together, these results evidenced key factors that may be involved in the development of severe alterations in liver tissues of children in response to DENV infection.

Immunopathology of Renal Tissue in Fatal Cases of Dengue in Children.

Dengue virus (DENV) infection represents a worldwide public health concern and can cause damage to multiple organs, including the kidney. In this work, we investigated the histopathological changes caused by dengue virus infection along with the detection of inflammatory mediators, cytokines, and cell expression patterns in the renal tissue of three fatal cases in children. Hematoxylin and Eosin staining was performed to analyze these histopathological changes. Immunohistochemistry allowed for the detection of immunological inflammatory markers in renal tissues that were quantified and further analyzed. Vascular congestion, edema and glomerular infiltrate were observed in the three cases, in addition to the thickening of the matrix area around the glomerular capillaries and mononuclear infiltrate associated with vascular congestion in the medullary region. The renal tissues exhibited collagen deposition and high expression of CD68+ Mø, CD8+ T, CD56+ cells and MMP-9, and the cytokine profile was mainly characterized by the expression of IFN-γ and TNF-α. Additionally, the expression of RANTES, VEGFR-2 and VCAM-1 were observed. The replication of DENV was evidenced by the detection of the NS3 protein. These results contributed to clarifying the main factors that may be involved in changes in the renal tissue of fatal cases of dengue in children.

Histopathological and immunological characteristics of placentas infected with chikungunya virus.

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-ß 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.

Placental Alterations in a Chikungunya-Virus-Infected Pregnant Woman: A Case Report.

Chikungunya virus (CHIKV) is an arthropod-borne virus first isolated in Tanzania, Africa. The virus has spread to Asia as well as South and Central America through infected Aedes mosquitoes. Vertical transmission may also occur, and was first documented during a chikungunya outbreak in La Réunion Island in 2005. Since then, some authors have been discussing the role of the placenta in maternal-fetal CHIKV transmission. CHIKV infection is characterized by fever, headache, rash, and arthralgia. However, atypical manifestations and clinical complications, including neurological, cardiac, renal, ocular, and dermal, may occur in some cases. In this report, we describe the case of a pregnant woman infected by CHIKV during the third trimester of gestation, who presented with severe dermatological manifestations during the epidemic in Rio de Janeiro, Brazil in 2019. CHIKV RNA and antigens were detected in the placental tissue, which presented with histopathological (deciduitis, fibrin deposition, edema, fetal vessel thickening, and chorioamnionitis) and ultrastructural alterations (cytotrophoblast with mitochondrial swelling and dilated cisterns in endoplasmic reticulum, vesicles in syncytiotrophoblasts, and thickening of the basement membrane of the endothelium).

Cytokines and inflammatory mediators: Markers involved in interstitial damage to the pancreas in two dengue fever cases associated with acute pancreatitis.

Dengue viral (DENV) infections can lead to acute pancreatitis and associated tissue damage. This study examined the pancreas from two fatal cases of DENV for histopathological changes as well as for the detection of cytokines, and other inflammatory mediators. Tissue sections were prepared for examination by ultrastructural and histopathological techniques. Sections from the pancreas of non-infected individuals were prepared in parallel as a control. The presence of viral replication in macrophages was detected by co-staining for the proteins NS3 and CD68 by immunofluorescence. Immunohistochemistry was used to detect cells that expressed cytokines and inflammatory mediators to characterize the inflammatory response. Edema, acinar necrosis and fibrosis areas associated with a mononuclear infiltrate were found in infected tissues. The major site of virus replication appeared to be macrophages based on their exclusive presentation of the viral protein NS3. Pancreatic tissues from the infected individuals also displayed increased levels of high mobility group box-1, caspase-3, gelatinase B and tumor necrosis factor alpha compared to controls. The presence of virus replicating macrophages in the pancreas was associated with multiple changes in tissue structure that included elevated levels of cytokines and inflammatory markers that may differentiate acute pancreatitis due to DENV infections from other causes.

Zika Induces Human Placental Damage and Inflammation.

In Brazil, an epidemic of Zika virus (ZIKV) infections was declared in 2015 that coincided with alarming reports of microcephaly in newborns associated with mother infection. Although the virus has placental tropism, changes in the tissue morphology and immunity of infected patients have not yet been elucidated. Here, we investigated the histopathological and ultrastructural changes along with the immunological profile and the BDNF expression in rare placental material. Tissues were obtained in the 2015-2016 Brazilian epidemic, of ten ZIKV-infected patients during pregnancy, five resulting in cases of fetal microcephaly and five non-microcephaly, compared to five non-infected control placentae. Viral antigens were only detected in samples from the ZIKV infected patients. Infected placentae presented histopathological severe damage, while the ultrastructural evaluation showed abnormal organelles, such as clusters of virus-like particles consistent with the ZIKV dimensions. Increased infiltration of CD68+ and TCD8+ cells, expression of MMPs, cytokines (IFN-γ and TNF-α) and other immunological mediators (RANTES/CCL5 and VEGFR-2) confirmed excessive inflammation and vascular permeability dysfunction. An evaluation of BDNF showed a decrease that could modulate neuronal damage in the developing fetus. The placental changes caused by ZIKV are not pathognomonic, however, the data provide evidence that this infection leads to severe placental injury.

Fatal Dengue Cases Reveal Brain Injury and Viral Replication in Brain-Resident Cells Associated with the Local Production of Pro-Inflammatory Mediators.

Dengue is an arboviral disease caused by dengue virus (DENV), which is transmitted to humans by Aedes aegypti mosquitoes. Infection by DENV most commonly results in a mild flu-like illness; however, the disease has been increasingly associated with neurological symptomatology. This association draws attention to further investigations on the impact of DENV infection in the host's central nervous system. Here, we analyzed brain samples of three fatal dengue cases that occurred in 2002 during an outbreak in Rio de Janeiro, Brazil. Brain tissues of these cases were marked by histopathological alterations, such as degenerated neurons, demyelination, hemorrhage, edema, and increased numbers of astrocytes and microglial cells. Samples were also characterized by lymphocytic infiltrates mainly composed of CD8 T cells. DENV replication was evidenced in neurons, microglia and endothelial cells through immunohistochemistry and in situ hybridization techniques. Pro-inflammatory cytokines, such as TNF-α and IFN-γ were detected in microglia, while endothelial cells were marked by the expression of RANTES/CCL5. Cytoplasmic HMGB1 and the production of nitric oxide were also found in neurons and microglial cells. This work highlights the possible participation of several local pro-inflammatory mediators in the establishment of dengue neuropathogenesis.

Secondary syphilis presenting as Syphilide psoriasiforme: lessons from the older syphilology literature.

It is essential for health care providers to be familiared with the full spectrum of clinical presentations of syphilis. We present herein a case of syphilide psoriasiforme, an uncommon but well recognized clinical presentation of secondary syphilis. A 46-year-old HIV-infected female patient was referred to our attention with a presumptive diagnosis of palmoplantar psoriasis. On examination, there were exuberant pinkish-red papules and plaques covered with a thick silvery scale in the palms, flexor surfaces of the wrists, and the medial longitudinal arches of the feet. Serological and histopathological analyses uncovered the diagnosis of syphilis. Clinical remission was obtained after treatment. A detailed review of the literature on syphilide psoriasiforme, including descriptions from older syphilology textsis provided. The present case report emphasizes the need for clinicians to have a heightened awareness of the varied and unusual clinical phenotypes of syphilis.

Antiretroviral therapy-induced paradoxical worsening of previously healed Mycobacterium haemophilum cutaneous lesions in advanced HIV infection.

Mycobacterium haemophilum is a nontuberculous mycobacterium that causes localized or disseminated disease, mainly in immunocompromised hosts. We report the case of a 35-year-old HIV-infected woman who presented with several enlarging cutaneous lesions over the arms and legs. Histopathological examination revealed the diagnosis of a cutaneous mycobacterial disease. Mycobacterial analyses unveiled M. haemophilum infection. Six months after completion of a successful antimycobacterial treatment, she developed an immune reconstitution inflammatory syndrome (IRIS). This paradoxical relapse presented as tenderness, redness and swelling at the precise sites of the healed lesions and took place in the setting of significant recovery of the CD4 cell count (from 05 to 318 cells/mm 3 ). Microbiological analyses of these worsening lesions were negative, and they spontaneously remitted without the initiation of a novel antimycobacterial treatment cycle. M. haemophilum infection should always be considered as a cause of skin lesions in immunocompromised subjects. Physicians should be aware of the possibility of IRIS as a complication of successful antiretroviral therapy in HIV-infected patients with M. haemophilum infection.

Renal Injury in DENV-4 Fatal Cases: Viremia, Immune Response and Cytokine Profile.

Dengue virus (DENV) infections may result in asymptomatic cases or evolve into a severe disease, which involves multiple organ failure. Renal involvement in dengue can be potentially related to an increased mortality. Aiming to better understand the role of DENV in renal injury observed in human fatal cases, post-mortem investigations were performed in four DENV-4 renal autopsies during dengue epidemics in Brazil. Tissues were submitted to histopathology, immunohistochemistry, viral quantification, and characterization of cytokines and inflammatory mediators. Probably due the high viral load, several lesions were observed in the renal tissue, such as diffuse mononuclear infiltration around the glomerulus in the cortical region and in the medullary vessels, hyalinosis arteriolar, lymphocytic infiltrate, increased capsular fibrosis, proximal convoluted tubule (PCT) damage, edema, PCT debris formation, and thickening of the basal vessel membrane. These changes were associated with DENV-4 infection, as confirmed by the presence of DENV-specific NS3 protein, indicative of viral replication. The exacerbated presence of mononuclear cells at several renal tissue sites culminated in the secretion of proinflammatory cytokines and chemokines. Moreover, it can be suggested that the renal tissue injury observed here may have been due to the combination of both high viral load and exacerbated host immune response.

A Stillborn Multiple Organs' Investigation from a Maternal DENV-4 Infection: Histopathological and Inflammatory Mediators Characterization.

Dengue virus (DENV) is an emerging virus involved in outbreaks in Brazil. The association between the virus and vertical transmission, with disorders in the placenta, has raised a worldwide concern. On the 29th gestational week, a pregnant woman presented severe complications due to a DENV infection leading to maternal and fetus death. Postmortem analysis of fetal organs demonstrated the presence of DENV using reverse transcriptase polymerase chain reaction (RT-PCR) in the fetal brain and DENV non-structural protein 3 (NS3) staining in placenta and several peripheral fetal tissues, such as the brain, liver, lungs, and spleen. Histological analysis of the placenta and fetal organs revealed different types of tissue abnormalities, which included inflammation, hemorrhage, edema, and necrosis in placenta and tissue disorganization in the fetus, such as spongiform parenchyma, microglial inflammation, steatosis, hyalinose arteriolar, inflammatory cells in the alveolar septa, and disorganization of the lymphoid follicle. Increased cellularity (macrophage, Hofbauer cells and TCD8+ lymphocytes) and up-regulation of inflammatory mediators such as IFN-γ, TNF-α, RANTES/CCL5, MCP1/CCL2, and VEGF/R2 were detected in the liver, lung, spleen, brain, and placenta, supporting placental and fetus peripheral tissues inflammation. Maternal infection leading to the production of those vascular mediators may alter the vascular permeability, facilitating the virus entry and tissue and barrier dysfunction.

Palate ulcer, uvular destruction and nasal septal perforation caused by Sporothrix brasiliensis in an HIV-infected patient.

Sporotrichosis is a human and animal disease caused by dimorphic pathogenic species of the genus Sporothrix. We report a dramatic presentation of Sporothrix brasiliensis infection, with destruction of the nasal septum, soft palate, and uvula of an HIV-infected woman. She was successfully treated with amphotericin B deoxycholate followed by itraconazole. Sporotrichosis remains a neglected opportunistic infection in patients with AIDS and awareness of this potentially fatal infection is of utmost importance.

Gastrointestinal CMV Disease and Tuberculosis in an AIDS Patient: Synergistic Interaction between Opportunistic Coinfections.

The AIDS pandemic has made diseases such as tuberculosis, CMV disease, and other opportunistic infections more prevalent; these diseases may even be found to be associated among themselves, and the natural history of each disease may present in an unusual manner. We report the case of a 41-year-old man with HIV (CD4 of 144 cells/dL) and HCV with hematochezia due to tuberculosis in the ileocecal valve and descending colon and CMV tissue invasive disease in the esophagus and descending colon. Coinfection among tuberculosis and cytomegalovirus in the gastrointestinal tract was described only once in a patient with a recent diagnosis of HIV that affected the distal ileum and ascending colon. We will discuss the peculiarities of the case and the behavior of the immune system in the face of simultaneous opportunistic infections. This is a challenging scenario that has scarce publications and is of great clinical importance.

Placental Inflammation and Fetal Injury in a Rare Zika Case Associated With Guillain-Barré Syndrome and Abortion.

Zika virus (ZIKV) is an emerging virus involved in recent outbreaks in Brazil. The association between the virus and Guillain-Barré syndrome (GBS) or congenital disorders has raised a worldwide concern. In this work, we investigated a rare Zika case, which was associated with GBS and spontaneous retained abortion. Using specific anti-ZIKV staining, the virus was identified in placenta (mainly in Hofbauer cells) and in several fetal tissues, such as brain, lungs, kidneys, skin and liver. Histological analyses of the placenta and fetal organs revealed different types of tissue abnormalities, which included inflammation, hemorrhage, edema and necrosis in placenta, as well as tissue disorganization in the fetus. Increased cellularity (Hofbauer cells and TCD8+ lymphocytes), expression of local pro-inflammatory cytokines such as IFN-γ and TNF-α, and other markers, such as RANTES/CCL5 and VEGFR2, supported placental inflammation and dysfunction. The commitment of the maternal-fetal link in association with fetal damage gave rise to a discussion regarding the influence of the maternal immunity toward the fetal development. Findings presented in this work may help understanding the ZIKV immunopathogenesis under the rare contexts of spontaneous abortions in association with GBS.

BALB/c mice infected with DENV-2 strain 66985 by the intravenous route display injury in the central nervous system.

Dengue is a mild flu-like arboviral illness caused by dengue virus (DENV) that occurs in tropical and subtropical countries. An increasing number of reports have been indicating that dengue is also associated to neurological manifestations, however, little is known regarding the neuropathogenesis of the disease. Here, using BALB/c mice intravenously infected with DENV-2 strain 66985, we demonstrated that the virus is capable of invading and damaging the host's central nervous system (CNS). Brain and cerebellum of infected animals revealed histological alterations such as the presence of inflammatory infiltrates, thickening of pia matter and disorganization of white matter. Additionally, it was also seen that infection lead to altered morphology of neuroglial cells and apoptotic cell death. Such observations highlighted possible alterations that DENV may promote in the host's CNS during a natural infection, hence, helping us to better understand the neuropathological component of the disease.

Rapidly Progressive Disseminated Sporotrichosis as the First Presentation of HIV Infection in a Patient with a Very Low CD4 Cell Count.

Sporotrichosis is a human and animal disease caused by species of the Sporothrix schenckii complex. It is classically acquired through traumatic inoculation of fungal elements. Most frequently, sporotrichosis presents as a fixed cutaneous or as a lymphocutaneous form. A much smaller number of cases occur as cutaneous disseminated and disseminated forms. These cases require immediate diagnosis and management to reduce morbidity and mortality. We present the case of a 34-year-old male patient in whom the first presentation of HIV infection was a rapidly progressive sporotrichosis with multiple cutaneous lesions, a high fungal burden in tissues, and pulmonary involvement. He had an extremely low CD4 cell count (06/mm3). Treatment with amphotericin B deoxycholate led to complete clinical resolution. Sporotrichosis remains a neglected opportunistic infection among HIV-infected patients in Rio de Janeiro state, Brazil, and awareness of this potentially fatal infection is of utmost importance if treatment is not to be delayed and if potentially devastating complications are to be avoided.

Laryngeal paracoccidioidomycosis presenting as solitary true vocal fold disease.

Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides brasiliensis or P. lutzii. It is a neglected tropical infectious disease that poses a major public health burden in endemic areas of Latin America. Mucosae of the upper digestive and respiratory tracts are commonly involved and many patients have disease at multiple mucosal sites, with or without lung involvement. Mucosal PCM presenting as solitary true vocal fold disease is relatively rare. We present the case of a 67-year-old Brazilian forest guard who presented with a 6-month history of hoarseness and globus pharyngeus due to a solitary left true vocal fold infiltration and vegetation diagnosed as PCM. Silent pulmonary disease was also present. A laryngoscopy video is offered as supplemental material to this report. He completely remitted after surgical removal and amphotericin B deoxycholate treatment.

An unusual case of bacillary angiomatosis in the oral cavity of an AIDS patient who had no concomitant tegumentary lesions - case report and review.

Bacillary angiomatosis (BA) is an angioproliferative disease of immunocompromised patients that usually presents as vascular tumors in the skin and subcutaneous tissues. It is caused by chronic infections with either Bartonella henselae or B. quintana. Oral cavity BA is exceedingly rare and even rarer without simultaneous cutaneous disease. We report herein the case of a 51-year-old HIV-infected man who presented severe odynophagia and an eroded lesion on the hard palate that progressed to an oronasal fistula. No cutaneous lesions were recorded. Doxycycline led to complete resolution. To the best of our knowledge, only six previous cases of oral BA without tegumentary disease have been previously reported and none of them progressed to fistula.