Histopathologic and Immunohistochemical Assessment of Acute Respiratory Distress Syndrome (ARDS): Challenges and Complexities of Postmortem Diagnosis.

Acute respiratory distress syndrome (ARDS) is a life-threatening condition due to acute lung injury (ALI), characterized by rapid-onset respiratory failure, leading to the clinical manifestations of poor lung compliance, severe hypoxemia, and dyspnea. ARDS/ALI has many causes, most commonly related to infections (sepsis, pneumonia), traumas, and multiple transfusions. The objective of this study is to assess the performance of postmortem anatomopathological examination in identifying etiological agents associated with ARDS or ALI in deceased patients from the State of São Paulo from 2017 to 2018. A retrospective cross-sectional study was performed based on the final outcome obtained by histopathology, histochemical, and immunohistochemical examination for ARDS/ALI differential diagnosis at the Pathology Center of the Adolfo Lutz Institute in São Paulo, Brazil. Of the 154 patients clinically diagnosed with ARDS or ALI, 57% tested positive for infectious agents, and the most frequent outcome was influenza A/H1N1 virus infection. In 43% of cases, no etiologic agent was identified. The opportunity to establish a diagnosis, identify particular infections, confirm a microbiological diagnosis, and uncover unanticipated etiologies is provided by postmortem pathologic analysis of ARDS. A molecular assessment could improve the diagnosis accuracy and lead to research into host responses and public health measures.

Surveillance of hemorrhagic fever and/or neuroinvasive disease: challenges of diagnosis.

OBJECTIVE: To evaluate the performance of post mortem laboratory analysis in identifying the causes of hemorrhagic fever and/or neuroinvasive disease in deaths by arbovirus infection. METHODS: Retrospective cross-sectional study based on the differential analysis and final outcome obtained in patients whose samples underwent laboratory testing for arboviruses at the Pathology Center of the Adolfo Lutz Institute, in São Paulo, Brazil. RESULTS: Of the 1355 adults clinically diagnosed with hemorrhagic fever and/or neuroinvasive disease, the most commonly attributed cause of death and the most common final outcome was dengue fever. Almost half of the samples tested negative on all laboratory tests conducted. CONCLUSION: The failure to identify the causative agent in a great number of cases highlights a gap in the diagnosis of deaths of unknown etiology. Additional immunohistochemical and molecular assessments need to be added to the post-mortem protocol if all laboratory evaluations performed fail to identify a causative agent. While part of our findings may be due to technical issues related to sample fixation, better information availability when making the initial diagnosis is crucial. Including molecular approaches might lead to a significant advancement in diagnostic accuracy.

Surveillance of hemorrhagic fever and/or neuroinvasive disease: challenges of diagnosis

OBJECTIVE: To evaluate the performance of post mortem laboratory analysis in identifying the causes of hemorrhagic fever and/or neuroinvasive disease in deaths by arbovirus infection. METHODS: Retrospective cross-sectional study based on the differential analysis and final outcome obtained in patients whose samples underwent laboratory testing for arboviruses at the Pathology Center of the Adolfo Lutz Institute, in São Paulo, Brazil. RESULTS: Of the 1355 adults clinically diagnosed with hemorrhagic fever and/or neuroinvasive disease, the most commonly attributed cause of death and the most common final outcome was dengue fever. Almost half of the samples tested negative on all laboratory tests conducted. CONCLUSION: The failure to identify the causative agent in a great number of cases highlights a gap in the diagnosis of deaths of unknown etiology. Additional immunohistochemical and molecular assessments need to be added to the post-mortem protocol if all laboratory evaluations performed fail to identify a causative agent. While part of our findings may be due to technical issues related to sample fixation, better information availability when making the initial diagnosis is crucial. Including molecular approaches might lead to a significant advancement in diagnostic accuracy. DESCRIPTORS: Autopsy. Hemorrhagic Fevers, Viral, etiology. Arbovirus Infections, mortality

Surveillance of hemorrhagic fever and/or neuroinvasive disease: challenges of diagnosis

ABSTRACT OBJECTIVE To evaluate the performance of post mortem laboratory analysis in identifying the causes of hemorrhagic fever and/or neuroinvasive disease in deaths by arbovirus infection. METHODS Retrospective cross-sectional study based on the differential analysis and final outcome obtained in patients whose samples underwent laboratory testing for arboviruses at the Pathology Center of the Adolfo Lutz Institute, in São Paulo, Brazil. RESULTS Of the 1355 adults clinically diagnosed with hemorrhagic fever and/or neuroinvasive disease, the most commonly attributed cause of death and the most common final outcome was dengue fever. Almost half of the samples tested negative on all laboratory tests conducted. CONCLUSION The failure to identify the causative agent in a great number of cases highlights a gap in the diagnosis of deaths of unknown etiology. Additional immunohistochemical and molecular assessments need to be added to the post-mortem protocol if all laboratory evaluations performed fail to identify a causative agent. While part of our findings may be due to technical issues related to sample fixation, better information availability when making the initial diagnosis is crucial. Including molecular approaches might lead to a significant advancement in diagnostic accuracy.

Immunohistochemical Assessment of the Expression of Biliary Transportation Proteins MRP2 and MRP3 in Hepatocellular Carcinoma and in Cholangiocarcinoma.

Multidrug resistance-associated protein 2 (MRP2) is a multi-specific organic anion transporter predominantly expressed in the canalicular membrane of hepatocytes, epithelial cells from gallbladder and apical membranes of proximal tubular kidney epithelium whereas multidrug resistance-associated protein 3 (MRP3) is present in the basolateral membrane of hepatocytes and cholangiocytes. This study aims to detect the expression of these transporters in hepatocellular carcinoma (HCC) and in cholangiocarcinoma (CC), searching for evidences for future studies on differential diagnosis and on clinical essays. The immunohistochemical reactivity (IHC) of these transporters was assessed in tissue microarrays of 80 HCC and 56 CC cases using monoclonal antibodies and compared with anatomopathological (AP) variables. The positivity of MRP2 was observed in 92.3% of HCC and in 96.3% of CC. The detection of high MRP2 expression in HCC was not significantly different (p > 0.05) according to the size, number of nodules architectural pattern and growth pattern of HCC and CC. Regarding histological grades, 22/22 well moderately differentiated HCC versus 50/56 poorly differentiated HCC were positive for MRP2. A trend for lower expression in poor differentiation HCC was found. And 50/50 well/moderately differentiated CC versus 2/4 poorly/undifferentiated CC were positive for MRP2. This result showed a reduced expression (p = 0,0004) in poorly differentiated CC. MRP3 positivity was observed in 18.8% of HCC and was not significantly different according to AP parameters. MRP3 was expressed in 44.5% CC, with a trend for lower expression in less differentiated CC and significantly lower rates in the ductular histological subtype (p = 0.023). The high expression of MRP2 in HCC and in CC is conserved regardless most of the anatomopathological parameters, except for a trend of lower expression in less differentiated HCC and CC. The observation of lower MRP3 expression in less differentiated CC and, especially, in the histological subtype with expression of hepatic progenitor cell phenotypes leads to future opportunities to evaluate the expression of this marker in cholangiocarcinomas.

Differential Expression of Stem Cell Markers in Human Adamantinomatous Craniopharyngioma and Pituitary Adenoma.

BACKGROUND/AIMS: Although craniopharyngioma (CP) is histologically benign, it is a pituitary tumour that grows rapidly and often recurs. Adamantinomatous CP (ACP) was associated with an activating mutation in ß-catenin, and it has been postulated that pituitary stem cells might play a role in oncogenesis in human ACP. Stem cells have also been identified in pituitary adenoma. Our aim was to characterize the expression pattern of ABCG2, CD44, DLL4, NANOG, NOTCH2, POU5F1/OCT4, SOX2, and SOX9 stem cell markers in human ACP and pituitary adenoma. METHODS AND RESULTS: We studied 33 patients (9 ACP and 24 adenoma) using real-time quantitative PCR (RT-qPCR) and immunohistochemistry. SOX9 was up-regulated in ACP, exhibiting positive immunostaining in the epithelium and stroma, with the highest expression in patients with recurrence. CD44 was overexpressed in ACP as confirmed by immunohistochemistry. SOX2 did not significantly differ among the tumour types. The RT-qPCR array showed an increased expression of MKI67,OCT4/POU5F1, and DLL4 in all tumours. NANOG was decreased in ACP. ABCG2 was down-regulated in most of the tumours. NOTCH2 was significantly decreased in the adenomas. CONCLUSION: Our results confirm the presence of stem cell markers in human pituitary tumours as well as the different expression patterns of ACP and adenoma. These findings suggest that ACP may originate from a more undifferentiated cell cluster. Additionally, SOX9 immunodetection in the stroma and the highest expression levels related to the relapse of patients suggest a contribution to the aggressive behaviour and high recurrence of this tumour type.

Differential Expression of Stem Cell Markers in Human Adamantinomatous Craniopharyngioma and Pituitary Adenoma

Background/Aims: Although craniopharyngioma (CP) is histologically benign, it is a pituitary tumour that grows rapidly and often recurs. Adamantinomatous CP (ACP) was associated with an activating mutation in ß-catenin, and it has been postulated that pituitary stem cells might play a role in oncogenesis in human ACP. Stem cells have also been identified in pituitary adenoma. Our aim was to characterize the expression pattern of ABCG2, CD44, DLL4, NANOG, NOTCH2, POU5F1/OCT4, SOX2, and SOX9 stem cell markers in human ACP and pituitary adenoma. Methods and Results: We studied 33 patients (9 ACP and 24 adenoma) using real-time quantitative PCR (RT-qPCR) and immunohistochemistry. SOX9 was up-regulated in ACP, exhibiting positive immunostaining in the epithelium and stroma, with the highest expression in patients with recurrence. CD44 was overexpressed in ACP as confirmed by immunohistochemistry. SOX2 did not significantly differ among the tumour types. The RT-qPCR array showed an increased expression of MKI67,OCT4/POU5F1, and DLL4 in all tumours. NANOG was decreased in ACP. ABCG2 was down-regulated in most of the tumours. NOTCH2 was significantly decreased in the adenomas. Conclusion: Our results confirm the presence of stem cell markers in human pituitary tumours as well as the different expression patterns of ACP and adenoma. These findings suggest that ACP may originate from a more undifferentiated cell cluster. Additionally, SOX9 immunodetection in the stroma and the highest expression levels related to the relapse of patients suggest a contribution to the aggressive behaviour and high recurrence of this tumour type.

Experimental Zika virus infection induces spinal cord injury and encephalitis in newborn Swiss mice

A widespread epidemic of Zika virus (ZIKV) infection was reported in 2015 in South and Central America, with neurological symptons including meningoencephalitis and Guillain-Barré syndrome in adults, besides an apparent increased incidence of microcephaly in infants born to infected mothers. It is becoming a necessity to have a trustworthy animal model to better understand ZIKV infection. In this study we used newborn white Swiss mice as a model to investigate the ZIKV strain recently isolated in Brazil. ZIKV was inoculated via intracerebral and subcutaneous routes and analysed through gross histopathology and immunohistochemistry. Here we demonstrated first that the intracerebral group (ICG) displayed severe cerebral lesions, with neuronal death, presence of apoptotic bodies, white matter degeneration and neutrophil perivascular cuffing. In the subcutaneous group (SCG), we observed moderate cerebral lesions, morphologically similar to that found in ICG and additional myelopathy, with architectural loss, marked by neuronal death and apoptotic bodies. Interestingly, we found an intense astrogliosis in brain of both groups, with increased immunoexpression of GFAP (glial fibrillary acidic protein) and presence of hypertrophic astrocytes. The spinal cord of subcutaneous group (SCG) exhibited reduction of astrocytes, but those positive for GFAP were hypertrophic and presented prolonged cellular processes. Finally significant lesions in the central nervous system (CNS) were present in newborn mice inoculated by both routes, but SCG method led to an important neurological manifestations (including myelopathy), during a longer period of time and appears for us to be a better model for ZIKV infection.

Uma epidemia generalizada de infecção pelo vírus Zika (ZIKV) foi relatada em 2015 na América do Sul e Central, com sintomas neurológicos incluindo meningoencefalite e síndrome de Guillain-Barré em adultos, além de um aparente aumento da incidência de microcefalia em bebês nascidos de mães infectadas. Está se tornando uma necessidade ter um modelo animal confiável para entender melhor a infecção pelo ZIKV. Neste estudo, usamos camundongos suíços brancos recém-nascidos como modelo para investigar a cepa ZIKV recentemente isolada no Brasil. O ZIKV foi inoculado por via intracerebral e subcutânea e analisado por histopatologia macroscópica e imuno-histoquímica. Aqui, demonstramos primeiro que o grupo intracerebral (ICG) apresentou lesões cerebrais graves, com morte neuronal, presença de corpos apoptóticos, degeneração da substância branca e manguito perivascular de neutrófilos. No grupo subcutâneo (SCG), observamos lesões cerebrais moderadas, morfologicamente semelhantes às encontradas no ICG e mielopatia adicional, com perda arquitetônica, marcada por morte neuronal e corpos apoptóticos. Curiosamente, encontramos uma astrogliose intensa no cérebro de ambos os grupos, com aumento da imunoexpressão de GFAP (proteína ácida fibrilar glial) e presença de astrócitos hipertróficos. A medula espinhal do grupo subcutâneo (SCG) exibiu redução de astrócitos, mas os positivos para GFAP foram hipertróficos e apresentaram processos celulares prolongados. Finalmente, lesões significativas no sistema nervoso central (SNC) estavam presentes em camundongos recém-nascidos inoculados pelas duas vias, mas o método SCG levou a importantes manifestações neurológicas (incluindo mielopatia), por um período mais longo, e parece ser um modelo melhor para infecção por ZIKV.