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.

Clinical features and outcomes of patients with hemophagocytic lymphohistiocytosis at onset of systemic autoinflammatory disorder and compare with Epstein-Barr virus (EBV)-related hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease. In clinical practice, we have observed that some HLH patients who have features of systemic autoinflammatory diseases (SAIDs) exhibit unique clinical manifestations and outcomes different from other HLH patients.We analyzed data from 25 HLH patients who were considered to have SAIDs; data were collected from patients of our center between January 1, 2015 and September 1, 2018.The median age of the patients was 1.75 years. In the early phase, all patients had a fever and 92% of patients had a rash; 96% of patients had high white blood cell count (WBC), C-reaction protein, and erythrocyte sedimentation rate. With progression, the above laboratory results decreased gradually. During the HLH period, we compared SAIDs-related HLH and Epstein-Barr virus (EBV)-related HLH and found that rash was more common (92%, P < .001) and splenomegaly was less common (64%, P = .023) in SAIDs-related HLH. Further, WBC, ferritin, and Interleukin-6 levels in SAIDs-related HLH patients were higher than those in EBV-related HLH patients. In contrast, hemoglobin, triglyceride, sCD25, Interleukin-10, and interferon-γ levels in SAIDs-related HLH patients were lower compared with those in EBV-related HLH patients. SAIDs-related HLH patients received a modified HLH-2004 protocol at our center. Most patients had a good prognosis.We provide a summary of the unique clinical and laboratory features, treatment protocols, and outcomes of SAIDs patients with HLH at onset. The findings indicate that these patients had a better response to corticosteroids and cyclosporin compared with EBV-related HLH patients.

Genotyping of Cytomegalovirus from Symptomatic Infected Neonates in Iraq

Among all other viruses, human cytomegalovirus (HCMV) is the most frequent cause of congenital infection worldwide. Strain variation in HCMV may predict severity or outcome of congenital HCMV disease. Previous studies have associated a particular genotype with specific sequelae or more severe illness, but the results were contradictory. There are no previous studies addressing the genotype of HCMV in Iraq. Therefore, the present study is aimed at molecular detection and genotyping of HCMV isolated from symptomatic congenitally/perinatally infected neonates. This prospective study comprised 24 serum samples from symptomatic neonates with congenital/perinatal infection. Viral DNA was extracted from these serum samples; nested polymerase chain reaction was used to amplify the HCMV gB (UL55) gene. Polymerase chain reaction products of the second round of amplification were subjected to direct Sanger sequencing. Bioedit and MEGA5 software (EMBL-EBI, Hinxton, Cambridgeshire, UK) were used for alignment and construction of a phylogenetic tree. Human cytomegalovirus DNA was detected in 23 of 24 samples (95.8%). According to the phylogenetic analysis, three genotypes of the virus were identified; gB1, gB2, and gB3 genotypes. However, the gB4 genotype was not detected. Human cytomegalovirus gB3 was the most frequent genotype: 14 of 24 (58.33%) among symptomatic infected infants, followed by gB1 (6/24; 25%) and gB2 (4/24; 16.67%). A mixed HCMV infection with gB3/gB1 was detected in only one case. Human cytomegalovirus gB3 was the most predominant genotype among symptomatic congenitally/perinatally HCMV-infected neonates. No association was found between B3 genotype and specific clinical presentation. Jaundice was the most common clinical feature among symptomatically infected neonates, followed by hepatosplenomegaly.

Cold type autoimmune hemolytic anemia- a rare manifestation of infectious mononucleosis; serum ferritin as an important biomarker

BACKGROUND

Infectious mononucleosis is one of the main manifestations of Epstein - Barr virus, which is characterized by fever, tonsillar-pharyngitis, lymphadenopathy and atypical lymphocytes. Although 60% of patients with IMN develop cold type antibodies, clinically significant hemolytic anemia with a high ferritin level is very rare and validity of serum ferritin as an important biomarker has not been used frequently.

CASE PRESENTATION

18-year-old girl presented with fever, malaise and sore throat with asymptomatic anemia, generalized lymphadenopathy, splenomegaly and mild hepatitis. Investigations revealed that she had cold type autoimmune hemolysis, significantly elevated serum ferritin, elevated serum lactate dehydrogenase level with serological evidence of recent Epstein Barr infection. She was managed conservatively and her hemoglobin and serum ferritin levels normalized without any intervention following two weeks of the acute infection.

CONCLUSION

Cold type autoimmune hemolytic anemia is a rare manifestation of infectious mononucleosis and serum ferritin is used very rarely as an important biomarker. Management of cold type anemia is mainly supportive and elevated serum ferritin indicates severe viral disease.

[CLINICAL AND IMMUNOLOGICAL CRITERIA FOR THE ADVERSE COURSE OF INFECTIOUS MONONUCLEOSIS IN CHILDREN]

The article presents the results of our own studies to determine the criteria for the adverse variants of the course of infectious mononucleosis (IM) in children. The study was conducted in the regional children's infectious clinical hospital in Kharkov. 161 children aged three to fifteen years were under observation with diagnosis of infectious moninucleosis. Out of 161 ill children, 140 (86.9%) had moderate severity of disease, and 21 (13.1%) had severe forms. All children were prescribed standard clinical and laboratory-instrumental examinations. The diagnosis of IM was verified by PCR (detection of VEB DNA in the blood) and ELISA (anti-VEB Ig M and Ig G). In 140 children (86.9%) IM proceeded sharply, smoothly (the first group), in 21 (13.1%) - unfavorably (wave and / or prolonged course) - the second group. The groups were comparable according to age, the severity of the disease and other parameters. All children received therapy according to approved protocols (Order of the Ministry of Health of Ukraine No. 354 of 09.07.2004). Immune status of children was assessed by determining the relative contents of CD3 +, CD4 +, CD8 +, CD16 +, CD19 + blood cells with appropriate monoclonal antibodies, serum IgA, IgM, IgG concentration by Mancini and interleukin (IL) -1β cytokine response and - 4, tumor necrosis factor (TNF α) is a solid-phase enzyme-linked immunosorbent assay. Based on the results of observations, it was established that the prognostically unfavorable criteria of IМ at the stages of manifestation of disease include: generalized lymphadenopathy involving 5-6 groups of lymph nodes and a significant increasing of them, purulent tonsillitis, marked increasing of size of liver and spleen on the background of anemia, thrombocytopenia, neutropenia and the absence of atypical mononuclears in the complete blood count. There is a depression of the cellular link and an increase in the humoral mechanisms of immune responses in case of development of adverse course of IM.

Analysis of prognostic risk factors in children with Epstein-Barr virus-associated hemophagocytic syndrome

AIM

This study aims to analyze the prognostic risk factors in children with Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis (EBV-HLH).

METHODS

Seventy-four EBV-HLH patients were divided into two groups according to the specificity: clinical remission after four-week inductive therapy group and active disease group; death group and survival group. The risk factors that affect early efficacy and prognosis were analyzed.

RESULTS

Overall survival rate of the 74 children was 75.7%, while the recurrence rate was 13.5%. The one-year survival rate was 71.4±5.6%, and the three-year survival rate was 65.9±6.6%, with a median survival rate of 40±19.9 months. The multivariate logistic regression analysis showed that age was the primary risk factor that affected the first 4 weeks alleviation, and the severity of splenomegaly and WBC level upon hospitalization were the risk factors that affected the prognosis. Patients with spleen>4 cm had shorter survival time than those with spleen≤4 cm, and patients with WBC≥3×10(9)/L had longer survival time than those with WBC<3×10(9)/L, which exhibited significant differences.

CONCLUSION

Age negatively influences the early remission of EBV-HLH. WBC<3×10(9)/L and spleen>4 cm exhibited high correlation with the prognosis of EBV-HLH.

[Spontaneous rupture of the spleen after infectious mononucleosis]

Non-traumatic rupture of the spleen (NRS) is a rare but serious complication to infectious mononucleosis (IM) and it is important to have in mind, when patients have IM. Although splenectomy has been advocated as the appropriate treatment for this problem, the trend goes towards conservative treatment of the haemodynamically stable patients, but because of its rarity no clear guidelines have been suggested. We present a case of a 18-year-old boy with IM who had NRS with subcapsular haematoma and was treated conservatively. He recovered completely.

An adult case of systemic Epstein-Barr virus-positive T/natural killer-cell lymphoproliferative disorder with good outcome

Epstein-Barr virus-positive T/natural killer (NK)-cell lymphoproliferative disorder (EBV+T/NK LPD) encompasses a heterogeneous group of disorders that have a common feature with excessive lymphoid proliferation of mainly T cells and/or NK cells. This disease is rare, predominantly affects children and young adults, and associated with high mortality. Herein, we report a case of EBV+T/NK LPD that occurred in an old woman with good outcome. The patient presented with fever, splenomegaly, and pancytopenia. Computed tomography (CT) scan of the abdomen showed splenomegaly. The clinical impression was a malignant tumor of spleen, so splenectomy was performed. Microscopically, the architecture of the spleen was preserved. The white pulp Malpighian corpuscles were atrophied. The red pulp showed intact sinusoids and pulp cords with increased cellular infiltrate. The proliferating lymphoid cells were mostly small lymphoid cells with minimal or no nuclear atypia, mixed with rare medium-sized or large cells. Immunohistochemical study and in-situ hybridization showed that the EBER-positive lymphoid cells were positive for CD3 and CD56. They were also positive for cytotoxic molecules, such as T-cell restricted intracellular antigen (TIA1), granzyme B. The case exhibited polyclonal rearrangement of T-cell receptor gene (TCR) by polymerase chain reaction (PCR) studies. Without radiotherapy and chemotherapy, the patient is alive and well with no evidence of disease 25 months after surgery.

Does transient elastography (FibroScan®) have a role in decision making in hepatocellular carcinoma?

OBJECTIVES

Portal hypertension has been reported as a negative prognostic factor and a relative contraindication for liver resection. This study considers a possible role of fibrosis evaluation by transient elastography (FibroScan(®)) and its correlation with portal hypertension in patients with cirrhosis, and discusses the use of this technique in planning therapeutic options in patients with hepatocellular carcinoma (HCC).

METHODS

A total of 77 patients with cirrhosis, 42 (54.5%) of whom had HCC, were enrolled in this study during 2009-2011. The group included 46 (59.7%) men. The mean age of the sample was 65.2 years. The principle aetiology of disease was hepatitis C virus (HCV)-related cirrhosis (66.2%). Liver function was assessed according to Child-Pugh classification. In all patients liver stiffness (LS) was measured using FibroScan(®). The presence of portal hypertension was indirectly defined as: (i) oesophageal varices detectable on endoscopy; (ii) splenomegaly (increased diameter of the spleen to ≥ 12 cm), or (iii) a platelet count of <100,000 platelets/mm(3).

RESULTS

Median LS in all patients was 27.9 kPa. Portal hypertension was recorded as present in 37 patients (48.1%) and absent in 40 patients (51.9%). Median LS values in HCC patients with and without portal hypertension were 29.1 kPa and 19.6 kPa, respectively (r = 0.26, P < 0.04). Liver stiffness was used to implement the Barcelona Clinic Liver Cancer algorithm in decisions about treatment.

CONCLUSIONS

  The evaluation of liver fibrosis by transient elastography may be useful in the follow-up of patients with cirrhosis and a direct correlation with portal hypertension may aid in the evaluation of surgical risk in patients with HCC and in the choice of alternative therapies.

Ocular findings in a patient with virus-associated hemophagocytic syndrome

PURPOSE

To describe a case of virus-associated hemophagocytic syndrome with ocular changes resembling Vogt-Koyanagi-Harada disease prior to the systemic changes.

METHODS

A 51-year-old man presented with a sudden decline in vision. The patient was examined by fluorescein angiography, bone marrow biopsy, abdominal ultrasound, ocular examinations, and laboratory examinations.

RESULTS

Fluorescein angiography revealed uveitis resembling Vogt-Koyanagi-Harada disease. Bone marrow biopsy specimen demonstrated histiocytic hyperplasia and some hemophagocytes. Abdominal ultrasound findings indicated hepato-splenomegaly. And ocular examinations revealed hematocytopenia and hypoproteinemia.

CONCLUSION

The ocular changes resembling Vogt-Koyanagi-Harada disease observed in this study could be a kind of manifestation of virus-associated hemophagocytic syndrome in retina.

A neonate with petechiae and pancytopenia at birth as uncommon presentation of congenital HIV infection

The authors describe a Thai newborn boy who was presented with petechiae, hepatosplenomegaly and pancytopenia at birth caused by congenital HIV infection. His clinical presentations were appeared on the early onset after birth. The bone marrow finding has shown hypocellularity which was also rare in HIV-infected children.

Clinical and biochemical profile of dengue haemorrhagic fever in children in Delhi

The clinical and biochemical profile of dengue haemorrhagic fever (DHF) varies from epidemic to epidemic. We studied children hospitalized with DHF from September 2003 to December 2003. All were diagnosed, managed and monitored according to a standard protocol. Of the 34 who fulfilled the World Health Organization criteria of DHF, 22 (64.6%) were male. All patients presented with fever and hepatomegaly. Examination also revealed splenomegaly in 11 (32.4%), ascites in 6 (17.6%) and pleural effusion in 3 (8.8%). Common bleeding manifestations were positive tourniquet test in 22 (64.7%) and epistaxis in eight (23.5%). Most children had a platelet count of between 20,000/mm(3) and 50,000/mm(3) (56%). Bleeding manifestations were not related to platelet count (P > 0.05). Serum glutamic pyruvic transaminase (SGPT) >40 IU/L was seen in 22 (64.6%) patients, alkaline phosphate (ALP) >400 IU/L in 12 (35.3%) and serum bilirubin >1 mg% in 3 (8.8%). IgM dengue serology was positive in 68.5% cases. There was no significant difference in liver function tests with age or sex (P > 0.05). Clinical features of DHF varied from the previous epidemic. Hepatic dysfunction with increased levels of serum enzymes was common in DHF.

HHV-8+, EBV+ Multicentric Plasmablastic Microlymphoma in an HIV+ Man: The Spectrum of HHV-8+ Lymphoproliferative Disorders Expands

Human herpesvirus-8 (HHV-8) is associated with several distinct lymphoproliferative disorders: primary effusion lymphoma, multicentric Castleman disease (MCD), MCD-associated plasmablastic lymphoma and HHV-8+, Epstein-Barr virus (EBV)+ germinotropic lymphoproliferative disorder. We report the case of a human immunodeficiency virus (HIV)+ male with fever, generalized lymphadenopathy, and splenomegaly. Two peripheral lymph nodes were excised and showed features of MCD and a prominent proliferation of HHV-8+, EBV+, CD20, CD138, MUM1+, lambda dim+, Ig heavy chain plasmablasts and immunoblasts replacing some follicles. Subsequently, a splenectomy and biopsy of retroperitoneal lymph nodes were performed; the retroperitoneal and splenic hilar lymph nodes showed changes similar to those in the peripheral lymph nodes while the markedly enlarged spleen showed replacement of occasional white pulp by the HHV-8+, EBV+ large cells. The histologic features and coinfection by EBV and HHV-8 suggested a diagnosis of HHV-8+ germinotropic lymphoproliferative disorder. However, the occurrence in an HIV+ individual, the background of MCD, the widespread anatomic distribution and the aggressive clinical course tended to exclude germinotropic lymphoproliferative disorder, and to favor multifocal plasmablastic microlymphoma. The patient died shortly after surgery; postmortem examination showed progression to overt lymphoma. The marrow showed extensive hemophagocytosis, consistent with development of a hemophagocytic syndrome. This unique case has clinical features compatible with a MCD-associated plasmablastic lymphoproliferative disorder, with pathologic features intermediate between HHV-8+ plasmablastic microlymphoma, and HHV-8+ germinotropic lymphoproliferative disorder, although in contrast to both of these, in our case, light chain expression was dim and heavy chain was not detected.

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.

Avian hepatitis E virus in an outbreak of hepatitis–splenomegaly syndrome and fatty liver haemorrhage syndrome in two flaxseed-fed layer flocks in Ontario

Two commercial layer chicken flocks that were fed a flax-based diet beginning at 28 weeks of age for the production of omega-3 fatty-acid-enriched eggs experienced increased mortality when the birds reached 37 weeks. The average weekly mortality was 0.34% over a 20-week period, with peak mortality of 0.9% for 1 week. Reduced feed consumption, reduced body weight gain and poor peak production were noticed prior to the onset of increased mortality. A total of 245 birds were necropsied and 78% of these had lesions in the liver and spleen, with 44% of those necropsied having changes consistent with hepatitis-splenomegaly syndrome, with lesions ranging from acute periportal lymphoplasmacytic hepatitis to chronic severe cholangiohepatitis with haemorrhage, vasculitis and amyloidosis. A total of 11% of the birds had lesions typical of fatty liver haemorrhagic syndrome, and 22% had lesions found in both hepatitis-splenomegaly syndrome and fatty liver haemorrhagic syndrome. No significant bacteria or viruses were recovered from samples of the liver/bile or spleen but 11 of 21 bile samples contained avian hepatitis E virus RNA detectable with a reverse transcriptase-polymerase chain reaction assay. Comparative sequence analysis found identities of 82 to 92% and 78 to 80% between the helicase and capsid protein genes, respectively, of the virus detected in this outbreak and those of other avian hepatitis E virus isolates, suggesting extensive genetic heterogeneity in avian hepatitis E viruses in Ontario flocks.

In vivo interactions of ecotropic and polytropic murine leukemia viruses in mixed retrovirus infections

Mixed retrovirus infections are the rule rather than the exception in mice and other species, including humans. Interactions of retroviruses in mixed infections and their effects on disease induction are poorly understood. Upon infection of mice, ecotropic retroviruses recombine with endogenous proviruses to generate polytropic viruses that utilize different cellular receptors. Interactions among the retroviruses of this mixed infection facilitate disease induction. Using mice infected with defined mixtures of the ecotropic Friend murine leukemia virus (F-MuLV) and different polytropic viruses, we demonstrate several dramatic effects of mixed infections. Remarkably, inoculation of F-MuLV with polytropic MuLVs completely suppressed the generation of new recombinant viruses and dramatically altered disease induction. Co-inoculation of F-MuLV with one polytropic virus significantly lengthened survival times, while inoculation with another polytropic MuLV induced a rapid and severe neurological disease. In both instances, the level of the polytropic MuLV was increased 100- to 1,000-fold, whereas the ecotropic MuLV level remained unchanged. Surprisingly, nearly all of the polytropic MuLV genomes were packaged within F-MuLV virions (pseudotyped) very soon after infection. At this time, only a fractional percentage of cells in the mouse were infected by either virus, indicating that the co-inoculated viruses had infected the same small subpopulation of susceptible cells. The profound amplification of polytropic MuLVs in coinfected mice may be facilitated by pseudotyping or, alternatively, by transactivation of the polytropic virus in the coinfected cells. This study illustrates the complexity of the interactions between components of mixed retrovirus infections and the dramatic effects of these interactions on disease processes.

[Screening of adult patients with fever of unknown origin. A prospective study on the role of primary cytomegalovirus infection]

PATIENTS AND METHODS

In a three-year prospective survey of 135 consecutive adult patients referred for fever of unknown origin often associated with a broad spectrum of constitutional signs and symptoms, 21 (15.5%) were found to have a primary Cytomegalovirus infection.

RESULTS

In the majority of cases, this syndrome was consistently associated with altered white blood cell count, abnormal T-lymphocyte subsets and hepatosplenomegaly. On the other hand, altered white blood cell differential and serum hepatic enzymes, and constitutional signs and symptoms were absent with a rate ranging from 11.1% to 27.4% of cases, and an initial laboratory cross-reaction with anti-Epstein-Barr IgM antibodies was detected in 48.1% of episodes. Non-specific signs and symptoms were the only features in 27.4% of patients, thus confirming that this disorder may be still clinically underestimated in its real frequency, until virologic assays are carried out. An extensive and varied spectrum of subjective disturbances, sometimes of duration prolonged beyond six months involved nearly 30% of subjects, and lasted for 3-15 months after recovery of acute, primary Cytomegalovirus disease.

CONCLUSIONS

In a multidisciplinary (clinical, laboratory, and instrumental) workup for a fever of unknown origin, a rapid recognition of a primary Cytomegalovirus disease is useful to exclude alternative diagnoses, avoid unnecessary exposure to antimicrobial agents, and reassure patients of the benign and self-limiting course of their illness.

Hepatitis C virus-related thrombocytopenia: clinical and laboratory characteristics compared with chronic immune thrombocytopenic purpura

Thrombocytopenia can be a complication of hepatitis C viral (HCV) infection. However, there is little published data regarding the clinical and laboratory manifestations of HCV-related thrombocytopenia (HCV-TP) compared with adult chronic immune thrombocytopenic purpura (CITP). We reviewed the medical records for all patients evaluated for chronic thrombocytopenia by the Haematology Service between January 1996 and June 2000. All patients were screened for HCV infection at the time of initial diagnosis. Of 250 patients who fulfilled American Society of Hematology criteria for CITP, 76 (30%) were HCV seropositive. HCV-TP patients were older [mean age (+/-SD) 54.9 +/- 8 years vs. 40.3 +/- 8 years, P </= 0.001] and equally distributed between both sexes. HCV-TP patients had less severe thrombocytopenia, defined as platelet count </=10 x 10(9)/l (4% vs. 46% for CITP, P </= 0.001). However, 56 (74%) had a platelet count </=50 x 10(9)/l. Symptoms and signs of thrombocytopenia were less frequent in HCV-TP, but major bleeding was more frequent (25% vs. 10%, P = 0.0059). Serum cryoglobulins and anticardiolipin antibodies were more frequent in HCV-TP (90% and 62% respectively), but rare in CITP (7% and 15%, P </= 0.001 compared with HCV-TP). HCV infection can be associated with significant thrombocytopenia and appears to be a distinct clinical entity.

A relapsing inflammatory syndrome and active human herpesvirus 8 infection

We describe an immunocompetent 61-year-old woman who was negative for human immunodeficiency virus and who had recurrent human herpesvirus 8 (HHV-8) infection associated with a relapsing systemic inflammatory syndrome characterized by fever, lymphadenopathy, splenomegaly, edema, arthrosynovitis, and rash. Kaposi's sarcoma developed 10 months after the initial clinical presentation. A correlation was documented between the recurrent clinical manifestations and the HHV-8 load in plasma and peripheral-blood mononuclear cells. Histologic examination of an enlarged lymph node heavily infected with HHV-8 revealed an atypical lymphoproliferative disorder characterized by paracortical hyperplasia and collapsed primary and secondary follicles.

Hemodynamic assessment of splenomegaly in beta-thalassemia patients undergoing splenectomy

Splenomegaly is a common finding in beta-thalassemia; however, its hemodynamic features and its potential correlations with high output state and hepatic disorders, both also frequent in thalassemia, have not yet been assessed in these patients. Eight beta-thalassemia patients with the indication for splenectomy and no symptoms or signs of heart disease, aged 25.6+/-5.5 years, were studied. Preoperative assessment included hematological profile, liver biology, hepatitis virus serology, and echocardiography. During splenectomy, splenic artery blood flow and splenic vein pressure were directly measured and liver biopsies were taken. Preoperative echocardiographic data were compared with those of 34 healthy controls. The preoperative cardiac index was significantly elevated in patients (4.8+/-1.3 vs 3.4+/-1.1 l/min per m2 in controls, p<0.001). Splenic blood flow, although increased, was not particularly high, being 285+/-56 ml/min or 0.13+/-0.04 ml/min per g of splenic mass, representing 4.1+/-0.9% of total cardiac output (CO). Splenic vein pressure was considerably elevated (29.7+/-5.5 cmH2O). Hepatic fibrosis, iron deposition, and extramedullary foci were found in all eight biopsies. Serology was positive in five of eight cases. beta-thalassemia patients with extensive splenomegaly requiring splenectomy are characterized by high output state, increased splenic blood flow, which probably makes a limited contribution to CO elevation, and portal hypertension, manifest by increased splenic vein pressure and hepatic histopathological abnormalities.

Genetic identification of avian hepatitis E virus (HEV) from healthy chicken flocks and characterization of the capsid gene of 14 avian HEV isolates from chickens with hepatitis–splenomegaly syndrome in different geographical regions of the United States

Avian hepatitis E virus (HEV), a novel virus identified from chickens with hepatitis-splenomegaly (HS) syndrome, is genetically and antigenically related to human HEV. Recently, it was found that avian HEV antibody is also prevalent in healthy chickens. A prospective study was done on a known seropositive but healthy chicken farm to identify avian HEV isolates from healthy chickens. Fourteen chickens were randomly selected, tagged and monitored under natural conditions for 19 weeks. All 14 chickens were seronegative at the beginning of the study at 12 weeks of age. By 21 weeks of age, all 14 chickens had seroconverted to avian HEV antibody. None of the chickens had any sign of HS syndrome. Partial helicase gene and capsid gene sequences of avian HEV isolates recovered from a healthy chicken were determined and found to share 75-97 % nucleotide sequence identity with the corresponding regions of avian HEV isolates from chickens with HS syndrome. Thus far, only one strain of avian HEV from a chicken with HS syndrome has been genetically characterized for its capsid gene, therefore the capsid gene region of an additional 14 isolates from chickens with HS syndrome were also characterized. The capsid genes of avian HEV isolates from chickens with HS syndrome were found to be heterogeneic, sharing 76-100 % nucleotide sequence identity with each other. This study indicates that avian HEV is enzootic in chicken flocks and spreads subclinically among chickens in the United States and that the virus is heterogeneic.

Pathogenetical characterization of isolate MHV-60 of mouse herpesvirus strain 68

Infection of mice with mouse herpesvirus strain 68 (MHV-68) is an excellent small animal model of gammaherpesvirus pathogenesis in a natural host. We carried out comparative studies on MHV-60, another isolate of MHV-68. The acute infection of BALB/c mice inoculated intranasally (i.n.) with MHV-60 as well as its impact on tumor development were investigated. During the acute phase of infection the lungs were the main tissues infected. Our results show that MHV-60 has similar pathological features like other 4 isolates so far examined, namely MHV-72, MHV-78, MHV-Sumava inclusive of MHV-68. Nevertheless, MHV-60 differed from other isolates in following features: (i) the acute phase of infection was established very soon and lasted 10 days post infection (p.i.) in contrast to 14-28 days p.i. in the abovementioned isolates with a peak on days 3-5 p.i. The virus could also be recovered from the spleen, thymus and kidneys but not in other investigated organs. A lymphoproliferative response was associated with splenomegaly. At this time an increase in the number of leukocytes and appearance of atypical leukocytes in peripheral blood were observed. (ii) the infection was localized in the lungs and spleen, while in other isolates it was detected in a much broader scale of organs, and (iii) the acute phase of infection was accompanied by a massive splenomegaly, which was characteristic for the chronic phase of infection. Despite the fact that after clearance of the acute infection the virus was hardly detected, the tumor formation was later observed in 22% of infected mice as compared to 5% in control non-infected mice.

Murine γ-Herpesvirus-68-Induced IL-12 Contributes to the Control of Latent Viral Burden, but Also Contributes to Viral-Mediated Leukocytosis

Early IFN-alpha/beta production, followed by the development of a viral-specific CTL response, are critical factors in limiting the level of murine gamma-herpesvirus-68 (gammaHV-68) infection. Development of a long-lived CTL response requires T cell help, and these CTLs most likely function to limit the extent of infection following reactivation. The importance of IL-12 in the development and/or activity of Th1 cells and CTLs is well documented, and we investigated the kinetics and magnitude of gammaHV-68-induced IL-12 production. Following intranasal infection, IL-12 and IL-23 mRNA expression was up-regulated in lung and spleen and lung, respectively, followed by increased levels of IL-12p40 in lung homogenates and sera. Exposure of cultured macrophages or dendritic cells to gammaHV-68 induced secretion of IL-12, suggesting that these cells might be responsible for IL-12 production in vivo. gammaHV-68 infection of mice made genetically deficient in IL-12p40 expression (IL-12p40(-/-)) resulted in a leukocytosis and splenomegaly that was significantly less than that observed in syngeneic C57BL/6 mice. IL-12p40(-/-) mice showed increased levels of infectious virus in the lung, but only at day 9 postinfection. Increased levels of latent virus in the spleen at day 15 postinfection were also observed in IL-12p40(-/-) mice when compared with syngeneic C57BL/6 mice. An overall reduction in gammaHV-68-induced IFN-gamma production was observed in IL-12p40(-/-) mice, suggesting that most of the viral-induced IFN-gamma in C57BL/6 mice was IL-12 dependent. Taken together, these results suggest that gammaHV-68-induced IL-12 contributes to the pathophysiology of viral infection while also functioning to limit viral burden.

Successful treatment of human immunodeficiency virus-related Castleman's disease: a case report and literature review

Multicentric Castleman's disease is increasingly recognized as an aggressive illness with a rapidly fatal outcome in human immunodeficiency virus (HIV)-infected patients. In the absence of optimal therapy, various therapeutic interventions have been tested with disappointing results; only five reports with a successful outcome have been described. Presented herein is a 66-year-old HIV-infected man with multicentric Castleman's disease. Early administration of cyclophosphamide, doxorubicin, vincristine and prednisone resulted in prolonged clinical recovery. The relevant literature is also reviewed.

Evaluation of the WHO clinical case definition for pediatric HIV infection in Bloemfontein, South Africa

The WHO clinical case definition for pediatric HIV infection has been designed to be used in countries where diagnostic laboratory resources are limited. We evaluated the WHO case definition to determine whether it is a useful instrument to discriminate between HIV-positive and HIV-negative children. In addition, clinical features not included in this case definition were recorded. We recorded clinical data from 300 consecutively admitted children in a state hospital in Bloemfontein, South Africa, and tested these children for HIV infection. A total of 222 children were included in the study; 69 children (31.1 per cent) were HIV positive. The sensitivity of the WHO case definition in this study was 14.5 per cent, the specificity was 98.6 per cent. Apart from weight loss and generalized dermatitis, the signs of the WHO case definition were significantly more often seen in HIV-positive than in HIV-negative children. Of the clinical signs not included in the WHO case definition, marasmus and hepatosplenomegaly especially occurred more frequently in HIV-positive children. Based on these findings we composed a new case definition consisting of four signs: marasmus, hepatosplenomegaly, oropharyngeal candidiasis, and generalized lymphadenopathy. HIV infection is suspected in a child presenting with at least two of these four signs. The sensitivity of this case definition was 63.2 per cent, the specificity was 96.0 per cent. We conclude that in this study the WHO case definition was not a useful instrument to discriminate between HIV-positive and HIV-negative children, mainly because its sensitivity was strikingly low. The simplified case definition we propose, proved to be more sensitive than the WHO case definition (63.2 vs. 14.5 per cent), whilst its specificity remained high.

Macrophage protection by addition of glutathione (GSH)-loaded erythrocytes to AZT and DDI in a murine AIDS model

Monocyte-macrophages play a central role in HIV-1 infection because they are among the first cells to be infected and because later they are important reservoirs for the virus. Thus, newly designed therapies should take into account the protection of this cell compartment. Herein, we report the results obtained in a murine AIDS model, by the addition to AZT+DDI of a system (GSH-loaded erythrocytes) able to protect macrophages against HIV-1 infection. Five groups of LP-BM5-infected mice were treated as follows: one group was treated by AZT, one group was treated by DDI, one group was treated by the combination of both, another by GSH-loaded erythrocytes, and finally, one by the combination of all three. After 10 weeks of infection the parameters of the disease were studied and the proviral DNA content in different organs and in macrophages of bone marrow and of the peritoneal cavity was quantified. The results obtained show that mice treated with AZT+DDI+GSH-loaded erythrocytes showed proviral DNA content in the brain and in macrophages of bone marrow that was significantly lower than in mice treated with AZT+DDI. This study may help developing strategies aimed at blocking HIV-1 replication in its reservoirs in the body.

Heterogeneity and seroprevalence of a newly identified avian hepatitis e virus from chickens in the United States

We recently identified and characterized a novel virus, designated avian hepatitis E virus (avian HEV), from chickens with hepatitis-splenomegaly syndrome (HS syndrome) in the United States. Avian HEV is genetically related to but distinct from human and swine HEVs. To determine the extent of genetic variation and the seroprevalence of avian HEV infection in chicken flocks, we genetically identified and characterized 11 additional avian HEV isolates from chickens with HS syndrome and assessed the prevalence of avian HEV antibodies from a total of 1,276 chickens of different ages and breeds from 76 different flocks in five states (California, Colorado, Connecticut, Virginia, and Wisconsin). An enzyme-linked immunosorbent assay using a truncated recombinant avian HEV ORF2 antigen was developed and used to determine avian HEV seroprevalence. About 71% of chicken flocks and 30% of chickens tested in the study were positive for antibodies to avian HEV. About 17% of chickens younger than 18 weeks were seropositive, whereas about 36% of adult chickens were seropositive. By using a reverse transcription-PCR (RT-PCR) assay, we tested 21 bile samples from chickens with HS syndrome in California, Connecticut, New York, and Wisconsin for the presence of avian HEV RNA. Of the 21 bile samples, 12 were positive for 30- to 35-nm HEV-like virus particles by electron microscopy (EM). A total of 11 of the 12 EM-positive bile samples and 6 of the 9 EM-negative bile samples were positive for avian HEV RNA by RT-PCR. The sequences of a 372-bp region within the helicase gene of 11 avian HEV isolates were determined. Sequence analyses revealed that the 11 field isolates of avian HEV had 78 to 100% nucleotide sequence identities to each other, 79 to 88% identities to the prototype avian HEV, 76 to 80% identities to chicken big liver and spleen disease virus, and 56 to 61% identities to other known strains of human and swine HEV. The data from this study indicated that, like swine and human HEVs, avian HEV isolates are genetically heterogenic and that avian HEV infection is enzoonotic in chicken flocks in the United States.

Selective delivery of augmented IL-2 receptor signals to responding CD8+ T cells increases the size of the acute antiviral response and of the resulting memory T cell pool

CD8(+) T cells respond to IL-2 produced both endogenously and by CD4(+) Th during an antiviral response. However, IL-2R signals can potentially promote CD8(+) T cell death as well as proliferation, making it unclear whether IL-2R signals provide a predominantly positive or negative effect upon CD8(+) T cell responses to viral infection. To more precisely define the direct role of IL-2R signaling on CD8(+) T cells during the response to a virus, we examined the effect of delivering augmented IL-2R signals selectively to CD8(+) T cells responding to lymphocytic choriomeningitis virus infection. Although naive CD8(+) T cells are competent to produce IL-2, CD8(+) T cells lose this capacity upon differentiation into effector CD8(+) T cells. However, effector CD8(+) T cells do retain the capacity to produce GM-CSF upon Ag stimulation. Thus, to deliver enhanced autocrine IL-2R signals to CD8(+) T cells, we established a transgenic mouse strain expressing a chimeric GM-CSF/IL-2R (GMIL2R). As GM-CSF production is Ag dependent, the GMIL2R delivers an augmented IL-2R signal exclusively to CD8(+) T cells responding to Ag. Following lymphocytic choriomeningitis virus infection, GMIL2R transgenic mice exhibited an increase in both the peak CD8(+) T cell response achieved and the size of the resulting memory pool established. Upon secondary viral challenge, the GMIL2R also enhanced the proliferative response of memory CD8(+) T cells. Thus, our findings indicate that IL-2 delivery to responding CD8(+) T cells is a limiting factor in both the acute and memory antiviral responses.

Progressive intrathoracic lymphadenopathy: EBV associated non-Hodgkin's lymphoma

A 30 year old man presented with late stage HIV disease and intrathoracic lymphadenopathy. Histology of a mediastinal biopsy suggested infective follicular hyperplasia or a peripheral T cell lymphoma. Subsequently, Epstein-Barr virus (EBV) infection was demonstrated in lymphocytes in the biopsy. Later, hepatosplenomegaly and peripheral lymphadenopathy developed. Histology of a cervical lymph node biopsy showed EBV associated diffuse large B cell (non-Hodgkin's) lymphoma.

Murine gammaherpesvirus-68-induced interleukin-10 increases viral burden, but limits virus-induced splenomegaly and leukocytosis

Based on its genomic sequence and its pathogenesis, murine gammaherpesvirus-68 (gammaHV-68) has been established as a tractable model for the study of viral infections caused by the human gammaherpesviruses, Epstein-Barr virus or human herpesvirus-8. Despite significant advances, the mechanisms responsible for gammaHV-68-induced alterations in the protective host response, and the accompanying virus-induced leukocytosis, are not clear. In the present study, we questioned whether viral infection resulted in endogenous interleukin-10 (IL-10) production that might alter the host response. Infection of C57BL/6 mice resulted in increased IL-10 expression, demonstrating that gammaHV-68 could induce endogenous production of this cytokine. Infected C57BL/6 mice demonstrated the characteristic splenomegaly associated with this viral infection, however, we were surprised to discover that the splenomegaly was greater in syngeneic mice genetically deficient in IL-10 (IL-10-/-). These results strongly suggested that endogenously produced IL-10 might serve to limit leukocytosis in wild-type mice. Quantification of viral burden demonstrated a significant elevation in C57BL/6 versus IL-10-/- mice, with increases in virus being observed in both the macrophage and B-lymphocyte populations. The decreased viral load in syngeneic IL-10-/- mice correlated with an increased expression of endogenous IL-12, suggesting a mechanism of protection that was IL-12 dependent. Taken together, these studies demonstrate a surprising dichotomy for endogenous IL-10 production during gammaHV-68 infection. While the lack of IL-10 results in increased IL-12 expression and a lower viral burden, IL-10-/- mice also experience an increased leukocytosis.

Murine gammaherpesvirus-68-induced interleukin-10 increases viral burden, but limits virus-induced splenomegaly and leukocytosis

Based on its genomic sequence and its pathogenesis, murine gammaherpesvirus-68 (gammaHV-68) has been established as a tractable model for the study of viral infections caused by the human gammaherpesviruses, Epstein-Barr virus or human herpesvirus-8. Despite significant advances, the mechanisms responsible for gammaHV-68-induced alterations in the protective host response, and the accompanying virus-induced leukocytosis, are not clear. In the present study, we questioned whether viral infection resulted in endogenous interleukin-10 (IL-10) production that might alter the host response. Infection of C57BL/6 mice resulted in increased IL-10 expression, demonstrating that gammaHV-68 could induce endogenous production of this cytokine. Infected C57BL/6 mice demonstrated the characteristic splenomegaly associated with this viral infection, however, we were surprised to discover that the splenomegaly was greater in syngeneic mice genetically deficient in IL-10 (IL-10-/-). These results strongly suggested that endogenously produced IL-10 might serve to limit leukocytosis in wild-type mice. Quantification of viral burden demonstrated a significant elevation in C57BL/6 versus IL-10-/- mice, with increases in virus being observed in both the macrophage and B-lymphocyte populations. The decreased viral load in syngeneic IL-10-/- mice correlated with an increased expression of endogenous IL-12, suggesting a mechanism of protection that was IL-12 dependent. Taken together, these studies demonstrate a surprising dichotomy for endogenous IL-10 production during gammaHV-68 infection. While the lack of IL-10 results in increased IL-12 expression and a lower viral burden, IL-10-/- mice also experience an increased leukocytosis.

Recurrent infectious mononucleosis caused by Epstein-Barr virus with persistent splenomegaly

We present the clinical case of a 20-year-old male soldier who appeared in general good physical condition. He suffered from infectious mononucleosis caused by Epstein-Barr virus that had recurred 2 years after the first serologically documented episode. The detected splenomegaly persisted in the healthy young man, who otherwise showed no apparent immune deficiency. To our knowledge, this is an extremely rare condition.

Clinical and laboratory findings of cytomegalovirus infection in 115 hospitalized non-immunocompromised adults

We report a retrospective study of 115 hospitalized non-immunocompromised adults with proved or presumed diagnosis of cytomegalovirus infection. Clinical symptoms were fever (95%), constitutive symptoms (80%), joint and muscle pain (41%), shivering (32%), abdominal pain (26%), non-productive cough (20%), cutaneous eruption (20%), and diarrhea (10%). Examination found hepatomegaly (25%), splenomegaly (23%), cutaneous rash (20%), adenopathy (19%), pharyngitis (9%), jaundice (3%) or signs of meningeal irritation (1%). Seventeen patients had a gastrointestinal form (hepatitis, jaundice, colitis, antral gastritis or cholecystitis), eight had a pattern of hemopathy, two interstitial pneumonitis, two pericarditis, two immune thrombocytopenic purpura, two a polymyalgia rheumatica-like pattern, one thrombotic thrombocytopenic purpura, one cutaneous vasculitis and one meningoencephalitis. Sixty-four percent of the patients had atypical lymphocytosis. Hepatocellular injury occurred in 90% of the patients. Nineteen of the patients had biological immune abnormalities. Cytomegalovirus infection should be mainly suspected in any patient with persistent fever, isolated or associated with signs of poor specificity, or in some patients with visceral manifestations of initially unknown origin.

Hemophagocytic syndrome

This case report is about an elderly man who presented with a long-standing history of high-grade fever and weight loss. He initially had only hepatosplenomegaly, but then developed jaundice. He also had pancytopenia and raised liver enzymes. His septic screen was negative, but he had a positive Monospot test and immunoglobulin G for Epstein-Barr virus. The liver biopsy showed sinusoidal phagocytosis and the subsequent bone marrow aspiration and biopsy showed significant hemophagocytosis, hence Hemophagocytic syndrome was diagnosed. The fever was refractory to antibiotic and anti-tuberculosis therapy, but it responded only partially to steroids. Full response was only noticed following anti-viral treatment in the form of intravenous Ganciclovir. The patient's general condition, liver enzymes, bilirubin, hematological parameters and even the weight returned back to their normal range 2 weeks after Ganciclovir therapy. Cessation of this drug resulted in relapse of his symptoms and oral antivirals did not help. Splenectomy, steroid pulse therapy and immunosuppressive treatment were only partially helpful. Reintroduction of Ganciclovir did help for a short period. We conclude that our patient had virus-associated hemophagocytic syndrome most likely related to Epstein-Barr virus infection, which was then confirmed by the splenic biopsy, and that Ganciclovir can be of great help in eradicating the virus and treating the disease, provided that it is given for a long enough period.

Rapid tumor formation and development of neutrophilia and splenomegaly in nude mice transplanted with human cells expressing human T cell leukemia virus type I or Tax1

Human T cell leukemia virus type I (HTLV-I) or its transcriptional transactivator, Tax1, was introduced into a human osteosarcoma cell line, HOS, and a Moloney murine sarcoma virus-positive HOS cell line, S+L-HOS. These HTLV-I- or Tax1-expressing cells were injected subcutaneously into nude mice to investigate the effects of HTLV-I on their tumorigenicities. HOS cells did not form any tumors even in the presence of HTLV-I or Tax1. S+L-HOS cells did form small tumors in two-thirds of nude mice. Infection of S+L-HOS cells with HTLV-I, or transduction of Tax1 into S+L-HOS cells markedly facilitated the tumor formation, and the tumor-bearing mice showed marked splenomegaly and neutrophilia. Elevated levels of granulocyte colony-stimulating factor (G-CSF) were detected in sera of these mice and also in the culture supernatants of Tax1-expressing human cells, suggesting that G-CSF in the mouse sera was produced by the human cells. In sera of some mice with splenomegaly and neutrophilia, high levels of murine granulocyte-macrophage colony-stimulating factor (mGM-CSF) were observed, suggesting that Tax1 produced by human cells induced mouse cells to produce mGM-CSF. Only S+L-HOS cell lines expressing Tax1 showed high tumorigenicity in nude mice. Thus, this system will be a useful model of tumor formation, splenomegaly and neutrophilia dependent on Tax1.

Different immunological requirements for protection against acute versus persistent Friend retrovirus infections

The propensity of retroviruses to rapidly establish persistent infections poses a formidable problem in vaccination strategies. In the current study, we use a live attenuated vaccine to study protection against acute and persistent Friend virus infections in mice. Adoptive transfers of immune CD8(+) T cells combined with passive immunizations with virus-neutralizing antibodies increased protection against acute disease compared with either treatment alone, but there was no protection against the establishment of persistent infection. In addition, the protection against acute disease elicited by the combination treatment was dependent on endogenous CD4(+) T cells as no protection was achieved in CD4(+) T-cell-depleted mice. Quantitative studies showed that doubling the numbers of immune lymphocytes used in adoptive transfer experiments increased protection against acute disease depending on the type of lymphocyte subset used in the transfer. CD8(+) T cells were the most potent subset for the transfer of such protection. However, even high numbers of immune CD8(+) T cells gave no protection against the establishment of persistent infections. The data indicate that strengthening the numbers of specific immune cell subsets may have a beneficial effect on protection against acute disease, but protection from establishment of persistence requires complex immune responses involving multiple lymphocyte subsets.

Lymphotoxin-alpha-deficient mice can clear a productive infection with murine gammaherpesvirus 68 but fail to develop splenomegaly or lymphocytosis

Respiratory challenge with murine gammaherpesvirus 68 (MHV-68) leads to an acute productive infection of the lung and a persistent latent infection in B lymphocytes, epithelia, and macrophages. The virus also induces splenomegaly and an increase in the number of activated CD8 T cells in the circulation. Lymphotoxin- alpha-deficient (LTalpha(-/-)) mice have no lymph nodes and have disrupted splenic architecture. Surprisingly, in spite of the severe defect in secondary lymphoid tissue, LTalpha(-/-) mice could clear a productive MHV-68 infection, although with delayed kinetics compared to wild-type mice, and could control latent infection. Cytotoxic T-cell activity was comparable in the lungs and spleens of LTalpha(-/-) and wild-type mice. However, splenic gamma interferon responses were substantially reduced in LTalpha(-/-) mice. Furthermore, LTalpha(-/-) mice failed to develop splenomegaly or lymphocytosis. Although germinal centers were absent, LTalpha(-/-) mice were able to class switch and showed significant virus-specific antibody titers. This work demonstrates that organized secondary lymphoid tissue is not an absolute requirement for the generation of immune responses to viral infections.

Massive splenomegaly and Epstein-Barr virus-associated infectious mononucleosis in a patient with Gaucher disease

PURPOSE

Gaucher disease should be considered in the differential diagnosis of a patient with Epstein-Barr virus (EBV) infection who has unexplained or disproportionate splenomegaly.

PATIENTS AND METHODS

A previously asymptomatic adolescent with EBV-associated infectious mononucleosis and massive splenomegaly is described. He was found to have Gaucher disease on bone marrow biopsy, which was performed to exclude a hematologic malignancy. The diagnosis was confirmed by assay of beta-glucosidase enzyme activity.

RESULTS

Regression of splenomegaly and improving hematologic indices.

CONCLUSION

Patients with infectious mononucleosis and disproportionate organomegaly should be investigated to exclude a hematologic malignancy or an underlying storage disorder such as Gaucher disease.

Origin and rapid evolution of a novel murine erythroleukemia virus of the spleen focus-forming virus family

The Friend spleen focus-forming virus (SFFV) env gene encodes a glycoprotein with apparent Mr of 55,000 that binds to erythropoietin receptors (EpoR) to stimulate erythroblastosis. A retroviral vector that does not encode any Env glycoprotein was packaged into retroviral particles and was coinjected into mice in the presence of a nonpathogenic helper virus. Although most mice remained healthy, one mouse developed splenomegaly and polycythemia at 67 days; the virus from this mouse reproducibly caused the same symptoms in secondary recipients by 2 to 3 weeks postinfection. This disease, which was characterized by extramedullary erythropoietin-independent erythropoiesis in the spleens and livers, was also reproduced in long-term bone marrow cultures. Viruses from the diseased primary mouse and from secondary recipients converted an erythropoietin-dependent cell line (BaF3/EpoR) into factor-independent derivatives but had no effect on the interleukin-3-dependent parental BaF3 cells. Most of these factor-independent cell clones contained a major Env-related glycoprotein with an Mr of 60,000. During further in vivo passaging, a virus that encodes an Mr-55,000 glycoprotein became predominant. Sequence analysis indicated that the ultimate virus is a new SFFV that encodes a glycoprotein of 410 amino acids with the hallmark features of classical gp55s. Our results suggest that SFFV-related viruses can form in mice by recombination of retroviruses with genomic and helper virus sequences and that these novel viruses then evolve to become increasingly pathogenic.

[AIDS splenomegaly and related iron problems]

Spleens collected from 85 consecutive autopsies of AIDS patients (mean age 37 years) were studied. Splenomegaly, observed in 59 cases (69.4%), does not statistically correlate with life style and blood transfusions. Eleven very large spleens (over 890 g) were associated with opportunistic infections (i.e.: mycobacteria, true fungi and rochalimaea). The histological pattern was characterized by marked lymphoid depletion of the white pulp and--in 67 cases (89.4%)--packing of the pulp cords by macrophages engulfed of brown pigment which was strongly positive to the Perls reaction for ferric iron. The contemporary presence of Perls positive and p24 immunoreactive material was diffusely observed in the cytoplasm of splenic macrophages, also positive to the alkaline tetrazolium reaction. The same was observed in the cytoplasm of monocytes/macrophages of lung and brain (in 5 out of 5 patients with splenomegaly > 600 g, randomly selected). We believe that our findings deal with the formation of a haemoglobin--p24 complex and are in keeping with recent data which suggest the formation of disulphide bonds between viral proteins and haemoglobin.

Elevation of soluble CD23 in sera from patients with infectious mononucleosis

CD23 is induced in B cells upon infection by Epstein-Barr virus (EBV) and a soluble form (soluble CD23: sCD23) is found in culture supernatants from EBV-transformed B cell lines. Based on these observations, we measured serum sCD23 levels in patients with infectious mononucleosis (IM) caused by EBV infection. Sera from patients with IM at the time of diagnosis contained more sCD23 than sera from normal control subjects. Changes in serum sCD23 levels during the course of disease showed that serum sCD23 levels were elevated at the time of diagnosis and they decreased to the normal levels during the convalescent phase defined by the improvement of symptoms of IM. These results indicate that the elevated levels of sCD23 were observed at the acute phase of IM and may be useful in diagnosing IM.