Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Investigation of a family with cancer in boys revealed that at least 20 males had the X-linked recessive lymphoproliferative syndrome. A variety of phenotypes occurred: aproliferative phenotypes consisted of aplastic anemia, agranulocytosis or acquired hypogammaglobulinemia; and proliferative phenotypes of B cells included disorders associated with the Epstein-Barr virus, American Burkitt's lymphoma, immunoblastic sarcoma of B cells, fatal infectious mononucleosis or plasmacytoma. The lymphoproliferative disorders observed in males could have resulted from an immunodeficiency to Epstein-Barr virus. The variable phenotypic expression could have resulted from individual differences in the viral dose, duration of exposure and age at which the boys were exposed to the virus. Aproliferative phenotypes such as acquired hypogammaglobulinemia could have ensued from excessive suppressor-cell activity on B cells, whereas proliferative phenotypes such as Burkitt's lymphoma or fatal infectious mononucleosis could have resulted from infection by Epstein-Barr virus and failure to stop proliferation of B cells.
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PMID:Variable phenotypic expression of an X-linked recessive lymphoproliferative syndrome. 19 60

The X-linked lymphoproliferative syndrome (XLP), also known as Duncan's disease, is an X-linked recessive disorder that is characterized by the inability of affected individuals to mount a sufficient immune response to Epstein-Barr virus (EBV). After EBV primary infection, male family members suffer from severe infectious mononucleosis (IM), aplastic anemia, hypogammaglobulinemia, and a spectrum of lymphoproliferative diseases. Autosomal mode of inheritance with similar symptoms as in XLP has been reported. We have studied two families with EBV-associated syndromes and an X-linked and an autosomal mode of inheritance, respectively. Affected family members presented with severe IM, hemophagocytosis, aplastic anemia, acquired hypogammaglobulinemia, and B-cell lymphoproliferative diseases.
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PMID:Epstein-Barr virus-associated lymphoproliferative syndromes: studies in two European families. 164 73

The human immune system has evolved multiple cellular and humoral defense mechanisms against the lymphotropic virus, EBV. NK cells, suppressor T-cells, cytotoxic K-cells, memory T-cells, and humoral immune responses usually subdue the virus into latency. Individuals with immune deficiency are at great risk of developing immunoregulatory disturbances and lymphoproliferative diseases when confronted by EBV. The infection of B-cells by EBV provokes a marked activation of immunoregulatory T-cells and requires restoration of immune homeostasis during convalescence. This is accomplished with difficulty in an individual with significant immune defects. The X-linked lymphoproliferative syndrome is an exemplary model for studying EBV in immune deficient individuals. Boys with XLP can develop acquired agammaglobulinemia, aplastic anemia, chronic or fatal IM, and a variety of B-cell malignant lymphomas following infection by the virus. We have identified multiple immune defects in the patients and progressive immunoregulatory disturbances following infection by the virus. Other patients with immune deficiency syndromes, i.e., ataxia telangiectasia or the renal transplant recipient, are also at increased risk for developing EBV-induced lymphoproliferative diseases. Moreover, certain families are at increased risk for EBV-associated malignancies, especially those with a triad of manifestations (i.e., autoimmunity, immunodeficiency, and lymphoma). Chromosomal breakage as seen in patients with ataxia telangiectasia may predispose to leukemogenesis. Immunoregulatory defects are also probably predisposing factors to lymphomagenesis. Both inherited and acquired defects can render persons vulnerable to leukemia and lymphoma.
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PMID:Immunodeficiency as a factor in lymphomagenesis. 633 Jun 65

X-linked lymphoproliferative syndrome (XLP) is a rare, often fatal, primary immunodeficiency disease characterized by an abnormal response to Epstein-Barr virus (EBV) infection. The gene responsible for XLP has been identified as SH2D1A/DSHP/SLAM-associated protein (SAP). The major clinical manifestations include fulminant infectious mononucleosis, lymphoproliferative disorder, and dysgammaglobulinemia. Affected males uncommonly present with lymphocytic vasculitis in addition to aplastic anemia. In this study, we describe a Japanese XLP patient who presented with hypogammaglobulinemia following acute EBV-induced infectious mononucleosis in the infancy and later had systemic lymphocytic vasculitis and hemophagocytic lymphohistiocytosis in the adulthood, which resolved by steroid pulse therapy. The patient's SAP gene was found to harbor a missense mutation (His8Asp), presumably resulting in defective expression of SAP in T cells. Biopsy specimens of lung and skin disclosed that CD8+ T cells predominantly infiltrated vascular vessels. However, immunohistochemical examination showed that EBV-infected cells were not identifiable in the vessels. We propose that T-cell-mediated immune dysregulation in XLP can cause vasculitis by EBV infection-unrelated mechanism.
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PMID:X-linked lymphoproliferative syndrome presenting with systemic lymphocytic vasculitis. 1568 26

X-linked lymphoproliferative disease (XLP) is an inherited immunodeficiency characterized by an extreme susceptibility to Epstein-Barr virus (EBV) infection. Patients with XLP mainly present with the 3 clinical manifestations of fulminant infectious mononucleosis, lymphoproliferative disorder, and dysgammaglobulinemia and in rare cases have aplastic anemia and lymphocytic vasculitis. The causative gene for XLP was identified as SH2D1A/DSHP/SLAM-associated protein (SAP) in 1998, and genetic analysis has been used for the definite diagnosis of XLP. Diagnosis for most patients occurs at ages younger than 10 years, and there are few adult patients. Here we describe a 23-year-old man with hypogammaglobulinemia and EBV-associated hemophagocytic lymphohistiocytosis and a diagnosis of XLP. In addition, the patient showed type 1 helper T-cell (Th1) skewing, as has been described in Sap knock-out mice. Th1/Th2 imbalance in humans, as well as in mice, may play an important role in the pathogenesis of XLP.
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PMID:X-linked lymphoproliferative disease in an adult. 1610 60

Epstein-Barr virus (EBV) is a ubiquitous human gamma-herpesvirus that infects about 95% of the adult population. The majority of primary infections occurs in early childhood and is generally subclinical; it can cause infectious mononucleosis (IM), which is usually a self-limiting lymphoproliferative disorder. However, infection of EBV occasionally results in severe, often lethal diseases, which include fatal IM, hemophagocytic syndrome, polyclonal lymphoproliferative disorders, and malignant lymphoma. These severe EBV-related illnesses occur secondary to some primary immunodeficiency diseases showing inefficient immune reaction to EBV. One example is X-linked lymphoproliferative disease (XLP), which is caused by mutations in the SLAM-associated protein (SAP) gene. The major clinical manifestations of XLP are fulminant IM, malignant lymphoma and dysgammaglobulinemia. Aplastic anemia, virus-associated hemophagocytic syndrome, and vasculitis have also been reported in XLP. We have developed a flow cytometric method using the anti-SAP monoclonal antibody to search for XLP. This clinically useful assay has successfully been used to identify XLP patients in Japan. In this review, clinical and mutational characteristics of XLP in Japan are mainly described. In addition, it is shown that the similar situations to XLP can occur in other primary immunodeficiencies involving T-cell killing function, such as autoimmune lymphoproliferative syndrome caused by Fas gene mutations or familial hemophagocytic lymphohistiocytosis caused by perforin gene mutations. Finally, the EBV-related terrible disease condition, namely chronic active EBV infection, which is common in Asian areas but its genetic background remains to be elucidated, will be touched on.
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PMID:Primary Immunodeficiencies Inducing EBV-Associated Severe Illnesses. 1730 92