Serological evidence of avian HEV antibodies in apparently healthy chickens in southwest Nigeria.

Avian hepatitis E virus (aHEV) is associated with hepatitis-splenomegaly syndrome, big liver and spleen disease and hepatic rupture haemorrhage syndrome. However, the knowledge about aHEV in commercial layer chickens in Nigeria is scarce. In this study, 460 serum samples obtained from 36 apparently healthy commercial layer chicken flocks in three states (Ogun, Osun and Oyo States) of southwestern Nigeria were analysed by enzyme linked immunosorbent assay for the presence of anti-aHEV immunoglobulin Y (IgY) antibodies. In total, the overall seroprevalence of anti-aHEV antibodies was 14.6%. The serological analysis revealed that 75% of the flocks examined were positive for anti-aHEV IgY antibodies from chickens of various ages in all three states. The percentage of the seropositive chickens in the three states varied from flock to flock ranging from 60% to 88.8% and seropositive chickens were detected at any age (24-52 weeks of age) without significant differences between the age groups. This is the first report assessing the presence of aHEV antibodies in chickens from Nigeria. The detection of anti-aHEV antibodies in commercial layer chickens in this study emphasizes the importance of serosurveillance in disease monitoring due to the economic threat posed by aHEV as a result of decreased egg production and increased mortality in affected commercial layer chicken farms. However, further studies are essential to reveal the clinical implications and to assess the real burden of aHEV in Nigeria.

A novel herpesvirus in a white stork associated with splenic and hepatic necrosis.

We identified a novel herpesvirus in a captive juvenile white stork (Ciconia ciconia) that experienced progressive weight loss followed by death. Histologic findings included severe splenic and hepatic necrosis, and intranuclear inclusion bodies in hepatocytes and unidentified splenic cells. The virus was amplified, sequenced, and subsequently accessioned as Ciconiid alphaherpesvirus 1. Phylogenetic analysis was performed and revealed that this virus is more closely related to mammalian herpesviruses than those within the genus Mardivirus. Additional sequence of viruses in this area may elucidate the ancestral virus that jumped from reptilian to mammalian hosts.

A NOVEL ORTHOREOVIRUS ASSOCIATED WITH EPIZOOTIC NECROTIZING ENTERITIS AND SPLENIC NECROSIS IN AMERICAN CROWS (CORVUS BRACHYRHYNCHOS).

Epizootic mortalities in American Crows (Corvus brachyrhynchos) during the winter months, referred to as winter mortality of crows, have been recorded in North America for almost two decades. The most common postmortem findings include necrotizing enteritis, colitis, and fibrinous splenic necrosis. These findings are proposed to be due to infection with a Reovirus sp. Our objectives were to characterize the pathology and seasonality of the epizootics in New York State (NYS), confirm the causative role of an Orthoreovirus sp., and determine its phylogeny. On the basis of our proposed case definition for reovirosis, we examined case data collected by the NYS Wildlife Health Program for 16 yr. A total of 558 cases of reovirosis were recorded between 2001 and 2017. Reovirosis had a clear seasonal presentation: cases occurred almost exclusively in winter months (71% in December-January). Detailed data from a 2-yr period (2016-17) demonstrated that reovirosis caused up to 70% of all recorded crow deaths during epizootic months. Crows with positive orthoreovirus isolation from the spleen or intestine were 32 times more likely to die with characteristic histologic lesions of enteritis or enterocolitis and splenic necrosis than crows with negative isolation results. An in situ hybridization probe specific to virus isolated from NYS crow reovirosis cases demonstrated a direct association between viral presence and characteristic histologic lesions. Sigma C (capsid protein) sequences of isolates from NYS crows showed high homology with Tvärminne avian virus, recently proposed as a novel Corvus orthoreovirus clade, and only distantly related to the avian orthoreovirus clade. Our study indicated that a novel orthoreovirus was the cause of winter mortality (or reovirosis) of American Crows and placed the NYS isolates in the newly proposed genus of Corvid orthoreovirus.

Splenic Epstein-Barr Virus-Associated Inflammatory Pseudotumor.

Splenic inflammatory pseudotumor (IPT) is an uncommon lesion with an inflammatory morphologic aspect that often poses a diagnostic challenge. The etiology of IPT can be infectious, autoimmune, reactive, or neoplastic. Splenic Epstein-Barr virus (EBV)-associated IPTs form a subset of splenic IPTs in which there is a spindle cell component infected by EBV. The best characterized and most frequent subgroup of splenic EBV-associated IPT is IPT-like follicular dendritic cell tumor. This review also focusses on EBV-associated splenic IPTs without follicular dendritic cell marker expression. These lesions are less well characterized, making the differential diagnosis with other splenic lesions even more difficult. Recently, increased numbers of immunoglobulin G4-positive plasma cells and the presence of numerous granulomas have been reported in EBV-associated IPTs, and this can add to the difficulties in recognizing the neoplastic nature of these lesions. Herein, we also review the epidemiology, clinical features, histologic morphology, immunohistochemistry, electron microscopy, and pathogenesis of EBV-associated IPTs.

Detection of Epstein-Barr virus in inflammatory pseudotumour of the spleen: a case report.

BACKGROUND: Various types of benign and malignant splenic tumours including hemangiomas, lymphagiomas, hamartomas, hemangiosarcomas, malignant lymphomas and metastatic carcinomas share radiological characteristics making it impossible for a physician to determine the definite aetiology of splenic masses noninvasively without histopathological evaluation. It is important that physicians recognize the importance of a careful and continuous follow-up since inflammatory pseudotumours (IPT) are considered to be tumours with an intermediate malignant potential based on their behaviour when they arise in other locations. METHODS: Our patient, a 60-year-old woman was evaluated using laboratory, gastroscopy, computed tomography and surgical methods. The resected tumour was evaluated using immunohistochemical methods. RESULTS: The patient presented with weight loss, nausea and vomiting, symptoms lasting over a course of a few months. The splenic mass was found incidentally at the time of work up for gastritis and cholelithiasis. Histologically, the tumour differed from typical splenic architecture being composed of atypical spindle cells with inflammatory elements; numerous plasma cells, macrophages, eosinophils and lymphocytes. CONCLUSIONS: Although very difficult to diagnose at initial presentation, it is very important for the physician to be aware of the importance of a careful diagnosis since IPT of the spleen are rare and considered to be tumours with an intermediate malignant potential.

Multimodality imaging of Epstein-Barr virus-associated inflammatory pseudotumor-like follicular dendritic cell tumor of the spleen: case report and literature review.

Inflammatory pseudotumors (IPTs) are rare tumors of unknown etiology; however, there is a strong association with the Epstein-Barr virus (EBV). EBV-positive IPTs are typically found in the liver and spleen. While many EBV-positive splenic IPTs contain follicular dendritic cell (FDC) proliferations, they are not aggressive such as with conventional FDC tumors. EBV-positive splenic IPTs have been reported with low malignant potential. We present a case with multimodality imaging of an EBV-positive IPT-like tumor with FDC features.

Inflammatory pseudotumor-like follicular dendritic cell tumor of liver and spleen: granulomatous and eosinophil-rich variants mimicking inflammatory or infective lesions.

Inflammatory pseudotumor-like follicular dendritic cell (FDC) tumor is an uncommon, Epstein-Barr virus-associated neoplasm of the liver or spleen, characterized by spindly tumor cells dispersed in a background of small lymphocytes and plasma cells. We report 6 diagnostically challenging cases in which the neoplastic component is further overshadowed by granulomas or eosinophils. The patients included 2 men and 4 women with a median age of 45.5 years, and 1 of them showed concurrent involvement of the liver and spleen. The presence of extensive coalescent epithelioid granulomas in 3 splenic tumors and 3 liver tumors raised the possibilities of an infective process or sarcoidosis. In another liver tumor, the massive infiltrate of eosinophils, accompanied by geographic eosinophilic abscesses, suggested parasitic infestation or so-called eosinophilic granuloma of the liver. However, scrutiny of the tissue between the granulomas or among the eosinophils revealed scattered atypical spindly cells with indistinct cell borders, large vesicular nuclei, and distinct nucleoli. The atypical cells were positive for FDC markers on immunostaining (CD21, CD35) and Epstein-Barr virus on in situ hybridization. Thus, a diagnosis of inflammatory pseudotumor-like FDC tumor could be confirmed. Awareness of the granulomatous and eosinophil-rich variants of this tumor type will facilitate the correct diagnosis to be made.

High production of interleukin-10 and interferon-γ in influenza-associated MERS in the early phase.

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) occurs in various diseases and pathologies, and the clinical symptoms are not consistent with the impaired region. The mechanism of the region specificity is unclear. We investigated the cytokine profiling in cerebrospinal fluid (CSF) and serum obtained from a child with MERS during influenza infection, and compared them with those of serious another serious type of influenza-associated encephalopathy. There was no elevation of Interleukin (IL)-1ß, which induces convulsion. The inhibitory cytokines of IL-10 and IFN-γ were elevated in the early phase in CSF. Comparing them with other patients, the elevation of the cytokine levels were generally mild. Considering that the prognosis of this MERS case was favorable and high levels of inhibitory cytokines including IL-10 and IFN-γ might work to localize the lesion and to prevent sequelae.

Epstein-Barr virus-positive inflammatory pseudotumour and inflammatory pseudotumour-like follicular dendritic cell tumour.

Various splenic inflammatory pseudotumours are reported to be infected with Epstein-Barr virus (EBV), which is thought to be associated with the pathogenesis of the lesion. The term "inflammatory pseudotumour (IPT)-like follicular dendritic cell tumour", all cases of which are also EBV positive, has recently been proposed. Here, we describe the imaging findings of these splenic tumours and present the cases of an IPT-like follicular dendritic cell tumour and two EBV-positive inflammatory pseudotumours in two female patients and one male patient. These splenic lesions were found incidentally on pre-operative or post-operative screening or at medical check-up. CT performed on all three patients revealed low-density solitary masses in the spleen. MRI was performed on one patient; the solitary mass demonstrated isointensity on T(1) weighted images and low intensity on T(2) weighted images relative to the surrounding splenic parenchyma. Dynamic MRI study revealed that the mass did not enhance on the early phase but enhanced to the same degree as the surrounding splenic parenchyma on the delayed phase. The imaging findings are almost identical to those found in conventional IPT because the morphology is similar in both cases; however, attention should be paid to this new entity in the diagnosis of splenic lesions because of its neoplastic nature. Longer follow-up is also necessary for these patients compared with those with conventional IPT.

Granulomatous inflammatory pseudotumor of the spleen: association with Epstein-Barr virus.

A 74-year-old woman with a clinical history of invasive ductal carcinoma of the breast was found to have a splenic mass during a routine radiographic survey. Splenectomy revealed a 3-cm well-demarcated lesion, which on histopathologic examination consisted of heterogeneous inflammatory cells. A striking feature of the lesion was the presence of innumerable well-formed non-necrotizing granulomas. Immunohistochemical studies confirmed the lesion to be composed mainly of mixed T and B lymphocytes, histiocytes, and plasma cells. No spindle cell component was evident on light microscopic examination or by immunohistochemical staining for smooth muscle actin, anaplastic lymphoma kinase, or follicular dendritic cell markers CD21 and CD35. Interestingly, Epstein-Barr virus-encoded RNA and latent membrane protein were detected by in situ hybridization and immunohistochemistry in numerous lymphohistiocytic cells within the lesion, but not in surrounding uninvolved splenic tissue. To our knowledge, this case represents a rare example of splenic inflammatory pseudotumor with exuberant granulomatous reaction in association with Epstein-Barr viral infection.

The prevention and management of infections in children with asplenia or hyposplenia.

Overwhelming sepsis remains a significant complication of asplenia and hyposplenia. The mainstays of prevention are education, immunization, and prophylactic antibiotics. Evidence to base recommendation and guidelines is lacking. Such decisions as the specific immunizations required, the timing of immunizations, the duration of antibiotic prophylaxis, and the prevention of overwhelming postsplenectomy sepsis in children undergoing splenectomy are often empiric. This article reviews the current literature on the prevention and management of severe infections in children with underlying asplenia or hyposplenia.

CD30 and Epstein-Barr virus RNA expression in sclerosing angiomatoid nodular transformation of spleen.

Sclerosing angiomatoid nodular transformation (SANT) is a splenic lesion composed of angiomatoid/vascular nodules surrounded by hyalinized/sclerotic stroma, fibroblasts, myofibroblasts, and inflammatory cells. The endothelium within the nodules has a phenotype resembling splenic sinusoids, capillaries, and small veins. Martel et al. (Am J Surg Pathol 28:1268-1279, 2004) suggested that SANT may represent the final pathway of a variety of splenic lesions including inflammatory pseudotumors (IPTs). Epstein-Barr virus (EBV) has a role in the genesis of some splenic IPTs, but its presence in SANT has not been investigated. Six cases of SANT are reported. All were stained for CD31, CD34, CD8, CD68, smooth muscle actin, muscle-specific actin, and CD30 and were tested for EBV by in situ hybridization (EBER). All cases showed angiomatoid nodules with complex expression of CD31, CD34, and CD8, with focal CD68. Expression of CD30 by endothelial cells was also seen. One case had small diffuse areas lacking nodules resembling an IPT and was positive for EBV. The inflammatory cells and the normal spleen were negative for CD30 and EBER. In conclusion, SANT shows upregulation of CD30 with respect to normal spleen. The presence of EBV in the stromal cells of a case supports the notion that a subset of SANT may be related to IPT.

Spontaneous splenic rupture in primary cytomegalovirus infection.

INTRODUCTION: Spontaneous splenic rupture is a rare occurrence in primary cytomegalovirus infection. CASES: We report two cases of spontaneous rupture of the spleen associated with primary cytomegalovirus infection in young immunocompetent adults. One patient had iron deficiency anemia, and the other a pyruvate kinase deficiency. Nonoperative management was successful in both cases. DISCUSSION: Nine other cases identified by a search of the medical literature are also reviewed. These cases do not show evidence of any particular risk factor.

A focused salivary gland infection with attenuated MCMV: an animal model with prevention of pathology associated with systemic MCMV infection.

While the salivary gland has been recognized as an important effector site of the common mucosal immune system, a useful model for studying anti-viral salivary gland immune responses in vivo and for exploring the role of the salivary gland within the common mucosal system has been lacking. Murine cytomegalovirus (MCMV) is a beta-herpesvirus that displays a strong tropism for the salivary gland and produces significant morbidity in susceptible mice when introduced by intraperitoneal (i.p.) inoculation. This study tested the hypothesis that MCMV morbidity and pathology could be reduced by injecting the virus directly the submandibular salivary gland (intraglandular (i.g.)), using either in vivo derived MCMV or the less virulent, tissue-culture-derived MCMV (tcMCMV). Peak salivary gland viral titers were completely unaffected by infection route (i.p vs. i.g.) after inoculation with either MCMV or tcMCMV. However, i.g. tcMCMV inoculation reduced viremia in all systemic tissues tested compared to i.p. inoculation. Furthermore, systemic organ pathology observed in the liver and spleen after i.p. inoculation with either MCMV or tcMCMV was completely eliminated by i.g. inoculation with tcMCMV. Cellular infiltrates in the salivary glands, after i.p. or i.g. inoculation were composed of both B and T cells, indicating the potential for a local immune response to occur in the salivary gland. These results demonstrate that a focused MCMV infection of the salivary gland without systemic organ pathology is possible using i.g. delivery of tcMCMV.

Inflammatory pseudotumor of the spleen with EBV positivity: report of a case.

Inflammatory pseudotumor (IPT) of the spleen is a rare benign tumor with unknown etiology. It causes problems in the diagnosis because of mimicking some hematopoetic malignancies. Here we report the case of a 36-yr-old woman complaining of nausea and insomnia. Laboratory investigations were limited to increase of leukocyte and thrombocyte count. Ultrasonography and magnetic resonance (MR) imaging showed circumscribed solid lobulated mass, measuring about 6.5 cm in diameter, located in the dorsal region of the spleen. Splenectomy was performed with the differential diagnosis including hamartoma and lymphoma of the spleen. Histological examination of the sharply demarcated splenic mass consisted of myofibroblasts and admixture of inflammatory cells. Immunohistochemistry and in situ hybridization were performed. IPT of the spleen was diagnosed. Epstein-Barr virus (EBV) was detected in the tumor by in situ hybridization. This rare entity is presented because of its clinical, radiological and pathological difficulties in the differential diagnosis.