Hypersensitivity to mosquito bites (HMB) is a rare disease characterized by intense skin reactions such as bulla and necrotic ulcerations at bite sites, accompanied by general symptoms such as high-grade fever and malaise occurred after mosquito bites. It has been suggested that HMB is associated with chronic Epstein-Barr virus (EBV) infection and natural killer (NK) cell leukemia/lymphoma. We describe here a Korean child who presented with 3-yr history of HMB without natural killer cell lymphocytosis. He has been ill for 6 yr with HMB. Close observation and examination for the development of lymphoproliferative status or hematologic malignant disorders is needed.
Child ; Epstein-Barr Virus Infections/complications ; Humans ; Hypersensitivity/*diagnosis/etiology ; Insect Bites and Stings/*diagnosis/pathology ; Killer Cells, Natural/immunology ; Lymphocytosis/complications/pathology ; Male ; Republic of Korea ; Skin/pathology

No abstract available.
Epstein-Barr Virus Infections/*complications/diagnosis ; Herpesvirus 4, Human/pathogenicity ; Humans ; Lymphoma, Follicular/complications ; Lymphoproliferative Disorders/*complications/diagnosis/virology ; Male ; Middle Aged ; *T-Lymphocytes/pathology/virology

Chronic infection with Epstein-Barr virus (EBV) without previous immunodeficiency or immuno-suppressive therapy is relatively rare. Severe chronic active EBV (SCAEBV) infection was reported for the first time in 1984 as 'chronic mononucleosis syndrome', and diagnostic criteria were proposed. It is characterized by clinical features including fever, severe hepatosplenomegaly, lymphadenopathy, hematologic features such as anemia and thrombocytopenia, and elevated antibody titers to EBV. We experienced a 21-year-old woman who initially presented with fever and chronic fatigue; however, no definite diagnosis could be made at the time of admission. Three months after the initial admission, there was evidence of only splenomegaly and the patient had persistent, multiple, paraaortic lymphadenopathies in abdominal CT. Diagnostic splenectomy was performed, and SCAEBV infection with T-cell lymphoproliferative disorder was ultimately diagnosed.
Adult ; Chronic Disease ; Diagnosis, Differential ; Epstein-Barr Virus Infections/*complications/*diagnosis ; Female ; Humans ; Lymphoproliferative Disorders/*diagnosis/pathology/virology ; Severity of Illness Index ; Splenectomy ; *T-Lymphocytes ; Tomography, X-Ray Computed

Epstein-Barr virus (EBV) is a ubiquitous herpesvirus, affecting >90% of the adult population. EBV targets B-lymphocytes and achieves latent infection in a circular episomal form. Different latency patterns are recognized based on latent gene expression pattern. Latent membrane protein-1 (LMP-1) mimics CD40 and, when self-aggregated, provides a proliferation signal via activating the nuclear factor-kappa B, Janus kinase/signal transducer and activator of transcription, phosphoinositide 3-kinase/Akt (PI3K/Akt) and mitogen-activated protein kinase pathways to promote cellular proliferation. LMP-1 also induces BCL-2 to escape from apoptosis and gives a signal for cell cycle progression by enhancing cyclin-dependent kinase 2 and phosphorylation of retinoblastoma (Rb) protein and by inhibiting p16 and p27. LMP-2A blocks the surface immunoglobulin-mediated lytic cycle reactivation. It also activates the Ras/PI3K/Akt pathway and induces Bcl-xL expression to promote B-cell survival. Recent studies have shown that ebv-microRNAs can provide extra signals for cellular proliferation, cell cycle progression and anti-apoptosis. EBV is well known for association with various types of B-lymphocyte, T-lymphocyte, epithelial cell and mesenchymal cell neoplasms. B-cell lymphoproliferative disorders encompass a broad spectrum of diseases, from benign to malignant. Here we review our current understanding of EBV-induced lymphomagenesis and focus on biology, diagnosis and management of EBV-associated B-cell lymphoproliferative disorders.
B-Lymphocytes/*pathology/*virology ; Diagnosis, Differential ; Disease Management ; Epstein-Barr Virus Infections/*complications ; Herpesvirus 4, Human/*physiology ; Humans ; Lymphoproliferative Disorders/*diagnosis/*etiology/therapy

We report a case of pure red cell aplasia (PRCA), which was initially suspected as a result of bone marrow involvement of diffuse large B cell lymphoma. Persistent anemia without an obvious cause was observed in a 47-yr-old man diagnosed with relapsed diffuse large B cell lymphoma. The bone marrow study showed only erythroid hypoplasia without the evidence of bone marrow involvement with lymphoma cells, thus PRCA was suggested. However, parvovirus infection was excluded as a potential cause of PRCA because of negative IgM anti-parvovirus B19 antibody and negative parvovirus PCR in the serum. Latent Epstein-Barr virus (EBV) infection of bone marrow was suggested by in situ hybridization with EBV-encoded small RNA (EBER) that showed a strong positive expression in bone marrow cells. Thus, PRCA was thought to be associated with latent EBV infection in bone marrow cells. Although the finding of unexplained anemia is a possible predictor of bone marrow involvement with lymphoma cells, PRCA as a result of a viral infection including EBV should be considered in lymphoma patients. This is the first report of the occurrence of PRCA associated with latent EBV infection in a patient with non-Hodgkin's lymphoma.
Adult ; Bone Marrow/pathology ; Bone Marrow Diseases/*complications/diagnosis/pathology ; Bone Marrow Neoplasms/pathology ; Diagnosis, Differential ; Epstein-Barr Virus Infections/*complications/diagnosis ; Humans ; Lymphoma, Large B-Cell, Diffuse/*complications/pathology ; Male ; Red-Cell Aplasia, Pure/diagnosis/*etiology

C1q nephropathy is a proliferative glomerulopathy with extensive mesangial deposition of C1q. A three-year old boy presented with a nephrotic-range proteinuria during an acute phase of Epstein-Barr virus (EBV) infection, and he had a family history of Dent's disease. The renal biopsy findings were compatible with C1q nephropathy. However, EBV in situ hybridization was negative. The CLCN5 gene analysis revealed an R637X hemizygous mutation, which was the same as that detected in his maternal cousin, the proband of the family. The causal relationship between EBV infection and C1q nephropathy remains to be determined. Moreover, the effects of underlying Dent's disease in the process of C1q nephropathy has to be considered.
Biopsy ; Child, Preschool ; Epstein-Barr Virus Infections/metabolism ; Glomerulonephritis/pathology ; Humans ; In Situ Hybridization ; Infectious Mononucleosis/*complications/*diagnosis ; Kidney Diseases/*complications/*diagnosis ; Kidney Tubules/*pathology ; Male ; Membrane Glycoproteins/*chemistry ; Mutation ; Nephrosis ; Proteinuria/*complications/*diagnosis ; Receptors, Complement/*chemistry ; Treatment Outcome

Various manifestations of brain involvement for patients with virus-associated hemophagocytic syndrome have been reported. Here, we report on the sequential magnetic resonance (MR) findings of acute demyelination of the entire brain with subsequent brain atrophy in a follow-up study of a 25-month- old boy who was admitted with fever and then diagnosed with infectious mononucleosis and EBV-associated hemophagocytic syndrome. We also review other conditions that should be included in the differential diagnosis of this disease.
Male ; *Magnetic Resonance Imaging ; Lymphohistiocytosis, Hemophagocytic/etiology/*pathology/virology ; Humans ; Epstein-Barr Virus Infections/complications/*pathology ; Diagnosis, Differential ; Demyelinating Diseases/complications/*pathology/virology ; Child, Preschool ; Brain Diseases/complications/*pathology/virology

Various manifestations of brain involvement for patients with virus-associated hemophagocytic syndrome have been reported. Here, we report on the sequential magnetic resonance (MR) findings of acute demyelination of the entire brain with subsequent brain atrophy in a follow-up study of a 25-month- old boy who was admitted with fever and then diagnosed with infectious mononucleosis and EBV-associated hemophagocytic syndrome. We also review other conditions that should be included in the differential diagnosis of this disease.
Male ; *Magnetic Resonance Imaging ; Lymphohistiocytosis, Hemophagocytic/etiology/*pathology/virology ; Humans ; Epstein-Barr Virus Infections/complications/*pathology ; Diagnosis, Differential ; Demyelinating Diseases/complications/*pathology/virology ; Child, Preschool ; Brain Diseases/complications/*pathology/virology

Hypersensitivity to mosquito bites (HMB) is a disorder characterized by a necrotic skin reaction and generalized symptoms subsequent to mosquito bites. It has been suggested that HMB is associated with chronic Epstein-Barr virus (EBV) infection and natural killer cell leukemia/lymphoma. We describe here a Korean child who had HMB associated with chronic EBV infection and natural killer cell lymphocytosis. A 5-yr-old boy was suffered from necrotic skin lesions on the right ear lobe. Type A EB virus was detected from hlood cells and bone marrow biospy recognized hemophagocyrosis.
Animals ; Child, Preschool ; Culicidae/*immunology ; Epstein-Barr Virus Infections/complications/*diagnosis ; Herpesvirus 4, Human/genetics/isolation & purification ; Humans ; Hypersensitivity/complications/*diagnosis ; Insect Bites and Stings/complications/*immunology ; Killer Cells, Natural/immunology/*pathology ; Lymphocytosis/complications/*diagnosis ; Male ; Polymerase Chain Reaction

Hypersensitivity to mosquito bites (HMB) is characterized by intense skin reactions at bite sites. The pathogenesis of HMB might be related to clonal lymphoproliferation of Epstein-Barr virus DNA-positive natural killer (NK) cells. We report the first case of HMB possibly associated with NK cell-derived large granular lymphocyte (NK-LGL) lymphocytosis in Korea.
Adult ; Animals ; Base Sequence ; *Culicidae ; Epstein-Barr Virus Infections/*complications/diagnosis ; Humans ; Hypersensitivity/*etiology/virology ; Insect Bites and Stings/*complications/immunology ; Killer Cells, Natural/*immunology/pathology ; Korea ; Lymphocytosis/*complications/pathology ; Male ; Molecular Sequence Data ; Polymerase Chain Reaction ; Prognosis ; Risk Assessment