1/120. Molecular tracking of an Human Immunodeficiency Virus nef specific cytotoxic T-cell clone shows persistence of clone-specific T-cell receptor dna but not mRNA following early combination antiretroviral therapy.The mechanisms that lead to maintenance of an active effector cytotoxic T-cell (CTL) response in Human Immunodeficiency Virus type-1 (hiv-1) infection are not well understood. We have investigated the role of antigen in maintenance of an hiv-1 specific CTL response by studying a patient (313-7) whose antigenic stimulus was reduced using antiretroviral drug therapy started within 90 days of hiv-1 infection. This patient made a primary monospecific CTL response to an HLA-C*0802 restricted epitope in nef (KAAVDLSHFL) prior to treatment. Within 7 days of starting treatment the nef specific CTL precursor frequency (CTLp) had decreased from 60/10(6) to 4/10(6) peripheral blood mononuclear cells (PBMC), coincident with a decline in viremia from 18 470 to 615 copies/ml. Both plasma viremia and nef specific CTLp remained at low levels for 180 days. The nef-specific CTL clone T-cell receptor (TCR) mRNA transcripts also decreased after treatment, but clone specific TCR dna persisted. It appears that removal of antigen alters the state of HIV specific CTL from an activated effector population (detected in the CTLp assay and by measurement of clone specific rna) to a non-activated quiescent population (detected by measurement of clone-specific dna). This latter population may represent persisting HIV specific memory CTL.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/120. Persistently negative hiv-1 antibody enzyme immunoassay screening results for patients with hiv-1 infection and AIDS: serologic, clinical, and virologic results. Seronegative AIDS Clinical Study Group.OBJECTIVE: To describe persons with HIV infection and AIDS but with persistently negative HIV antibody enzyme immunoassay (EIA) results. DESIGN: Surveillance for persons meeting a case definition for hiv-1-seronegative AIDS. SETTING: united states and canada. patients: A total of eight patients with seronegative AIDS identified from July 1995 through September 1997. MAIN OUTCOME MEASURES: Clinical history of HIV disease, history of HIV test results, and CD4 cell counts from medical record review; results of testing with a panel of EIA for antibodies to hiv-1, and hiv-1 p24 antigen; and viral subtype. RESULTS: Negative HIV EIA results occurred at CD4 cell counts of 0-230 x 10(6)/l, and at HIV rna concentrations of 105,000-7,943,000 copies/ml. Using a panel of HIV EIA on sera from three patients, none of the HIV EIA detected infection with hiv-1, and signal-to-cut-off ratios were < or = 0.8 or all test kits evaluated. Sera from five patients showed weak reactivity in some HIV EIA, but were non-reactive in other HIV EIA. All patients were infected with hiv-1 subtype B. CONCLUSIONS: Rarely, results of EIA tests for antibodies to hiv-1 may be persistently negative in some hiv-1 subtype B-infected persons with AIDS. physicians treating patients with illnesses or CD4 cell counts suggestive of HIV infection, but for whom results of HIV EIA are negative, should consider p24 antigen, nucleic acid amplification, or viral culture testing to document the presence of HIV.- - - - - - - - - - ranking = 0.66666666666667keywords = antigen (Clic here for more details about this article) |
3/120. An enlarged subpopulation of T lymphocytes bearing two distinct gammadelta TCR in an HIV-positive patient.Although T cell clone monospecificity is ensured by several allelic exclusion processes operating at either the genotypic or phenotypic levels, clones expressing two distinct alphabeta or gammadelta TCR have been described in several instances. Thus far, the origin of dual TCR-expressing cells and the homeostatic mechanisms controlling the size of this subset in the periphery remain poorly understood. In the course of a phenotypic analysis of gammadelta T cells in HIV-infected patients, we detected the presence of a T cell subset stained by both Vdelta2- and Vdelta3-specific mAb, which represented a large fraction (up to 16.5%) of gammadelta peripheral blood lymphocytes (PBL) in one HIV patient. The presence of two distinct functional delta chains on these cells was confirmed by phenotypic and molecular analysis of TCR transcripts expressed by Vdelta2 Vdelta3 T cell clones derived from this patient. For 18 months, the absolute number of these cells varied similarly to the other PBL subsets, before becoming undetectable in blood samples. Moreover, most of these cells expressed CD8 receptors, which are classically found on activated, but not resting, gammadelta T cells. Taken together, these data suggest that dual TCR-expressing T cells are subjected to peripheral expansions and contractions presumably following antigen recognition, which would argue against a systematic counter-selection of these cells during peripheral antigen-driven responses.- - - - - - - - - - ranking = 0.66666666666667keywords = antigen (Clic here for more details about this article) |
4/120. Coexistent gastric MALT lymphoma and Kaposi sarcoma in an HIV positive patient.A 47 year old HIV positive male presented with haematemesis and epigastric pain. A gastrectomy was performed for intractable bleeding. The cause of the haematemesis proved to be a Kaposi sarcoma of the stomach which had resulted in mucosal ulceration. Several other smaller foci of Kaposi sarcoma were also present. Coexistent with the Kaposi sarcoma was a dense lymphoid infiltrate with lymphoid follicles and reactive germinal centres. Centrocyte-like cells caused marked effacement and destruction of gastric glands with the formation of lymphoepithelial lesions, typical of a MALT lymphoma. These cells were of B cell lineage and some expressed the HIV antigen, p24. Follicular dendritic cells and macrophages within germinal centres were also p24 positive. immunohistochemistry and in situ hybridisation did not detect Epstein-Barr virus. Although helicobacter pylori was not identified by light microscopy in the sections sampled, this does not preclude its possible role, with other cofactors such as HIV, in the causation of the MALT lymphoma.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
5/120. central nervous system toxoplasmosis in acquired immunodeficiency syndrome: An emerging disease in india.With the incidence of patients infected with human immuno-deficiency virus (HIV) increasing in india, the central nervous system (CNS) manifestations of the disease will be seen more frequently. The CNS may be primarily afflicted by the virus or by opportunistic infections and neoplasms secondary to the immune suppression caused by the virus. In india, although mycobacterium tuberculosis has been reported to be the most common opportunistic infection, toxoplasmosis may become as common owing to the ubiquitous nature of the protozoan. Since an empirical trial of medical therapy without histopathological diagnosis is recommended, the true incidence of this condition may remain under estimated. The role of ancillary tests such as radiology and serology in the initial diagnosis of this condition remain crucial. This report highlights two patients who were diagnosed to have acquired immuno-deficiency syndrome (AIDS) only after the biopsy of the intracranial lesion was reported as toxoplasmosis. Presently all patients for elective neurosurgery are tested for HIV antigen. The management protocol to be followed in a known patient with AIDS presenting with CNS symptoms is discussed in detail. The value of ancillary tests is also reviewed.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
6/120. High frequency of cytomegalovirus-specific cytotoxic T-effector cells in HLA-A*0201-positive subjects during multiple viral coinfections.How the cellular immune response copes with diverse antigenic competition is poorly understood. Responses of virus-specific cytotoxic T lymphocytes (CTL) were examined longitudinally in an individual coinfected with human immunodeficiency virus type 1 (hiv-1), Epstein-Barr virus (EBV), and cytomegalovirus (CMV). CTL responses to all 3 viruses were quantified by limiting dilution analysis and staining with HLA-A*0201 tetrameric complexes folded with hiv-1, EBV, and CMV peptides. A predominance of CMV-pp65-specific CTL was found, with a much lower frequency of CTL to hiv-1 Gag and Pol and to EBV-BMLF1 and LMP2. The high frequency of CMV-specific CTL, compared with hiv-1- and EBV-specific CTL, was confirmed in an additional 16 HLA-A*0201-positive virus-coinfected subjects. Therefore, the human immune system can mount CTL responses to multiple viral antigens simultaneously, albeit with different strengths.- - - - - - - - - - ranking = 0.66666666666667keywords = antigen (Clic here for more details about this article) |
7/120. The use of paclitaxel and cisplatin in a patient with epithelial ovarian cancer and human immunodeficiency virus.OBJECTIVE: Several spots exist of human immunodeficiency virus (HIV)-positive patients developing epithelial ovarian cancer. The optimal chemotherapeutic regimen has been unclear due to potential immunotoxicity from chemotherapy in these already immunocompromised patients. This is the first report of paclitaxel-based combination chemotherapy in an HIV-positive patient with ovarian cancer. METHOD: A 39-year-old woman with HIV was diagnosed with poorly differentiated serous carcinoma. She underwent optimal cytoreductive surgery and received six courses of paclitaxel and cisplatin. RESULTS: The patient experienced a complete clinical response to therapy with no adverse effect on surrogate markers for human immunodeficiency virus (CD4 count, beta2 microglobulin, neopterin, p24 antigen, and viral load). CONCLUSION: paclitaxel- and platinum-based chemotherapy, the standard of care for adjuvant chemotherapy in advanced ovarian carcinoma, is appropriate therapy for ovarian cancer patients with HIV. There is no evidence that the paclitaxel/cisplatin regimen is associated with progression of HIV or increased chemotherapy-associated morbidity.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
8/120. Perianal cytomegalovirus ulcer in an HIV infected patient: case report and review of literature.We report the case of a 25-year-old man with acquired immunodeficiency syndrome, presenting with perianal ulcer and diarrhea. He had positive immunocytochemical tests for cytomegalovirus (CMV) in circulating polymorphonuclear cells (PMN). The biopsy specimen was suggestive of CMV infection, and specific immunoperoxidase for CMV antigens positively stained endothelial cells and fibroblasts. In this report we review cutaneous CMV infection in immunocompromised patients.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
9/120. Subacute hypersensitivity pneumonitis in an HIV infected patient receiving antiretroviral therapy.Abnormal pulmonary immune response to various antigens can lead to hypersensitivity pneumonitis. This disease has not previously been reported in HIV infected patients. This case report describes an HIV infected woman who developed subacute hypersensitivity pneumonitis in response to bird exposure. The disease manifested itself only after the patient experienced an improvement in her CD4 positive T lymphocyte count secondary to antiretroviral therapy. This case emphasises the need to consider non-HIV associated diseases in patients with HIV and suggests that diseases in which host immune response plays an essential role in pathogenesis may become more prevalent in HIV infected patients receiving effective antiretroviral therapy.- - - - - - - - - - ranking = 0.33333333333333keywords = antigen (Clic here for more details about this article) |
10/120. Failure of routine hiv-1 tests in a case involving transmission with preseroconversion blood components during the infectious window period.CONTEXT: Current screening practices for blood donations have been successful in reducing human immunodeficiency virus (HIV) transmission through receipt of contaminated blood products. However, HIV-infected blood donations made prior to seroconversion and before high levels of viral replication occur could test negative using both serologic antigen and antibody tests. Testing based on nucleic acid amplification (NAT) is being implemented to screen for HIV-infected blood donated during this period, yet the issue of single vs minipool donation screening remains unresolved. OBJECTIVES: To determine hiv-1 genetic linkage between virus in 2 hiv-1-infected recipients of blood components and virus in the donor, who was HIV antigen and antibody negative at the time of donation; to screen the blood donor's plasma with HIV NAT assays, including those currently proposed for use in US blood donation screening. DESIGN AND SETTING: Case study conducted in October 1997 involving the Communicable disease Centre, singapore General Hospital, and the singapore blood transfusion Service, singapore. SUBJECTS: The blood donor and the 2 recipients of donor platelets and red blood cells. MAIN OUTCOME MEASURES: Genetic analysis of the hiv-1 p17 coding region of gag and the C2V5 region of env to determine the genetic relatedness of virus from the donor and recipients; reactivity in quantitative and qualitative assays, and reactivity in donor screening HIV NAT assays in single donation and minipool screening contexts. RESULTS: Direct dna sequencing demonstrated identical hiv-1 subtype E viral sequences in the donor and recipients. Based on comparisons of a qualitative and quantitative assay for hiv-1 rna levels, a low level of viremia (range, 5-39 copies/mL in plasma) was estimated to be in the donor's undiluted blood at the time of donation. Additional testing using donor-screening NAT assays showed consistent detection of HIV rna in the undiluted donor plasma whereas detection was inconsistent at the 1:16 and 1:24 dilution levels currently used in minipool screening of blood donations in the united states. CONCLUSIONS: Transmission of HIV from a blood donor to a platelet recipient and a red blood cell recipient occurred in the preseroconversion infectious window period. The viral load in the implicated donation was estimated to be less than 40 copies/mL of plasma. Current US minipool HIV NAT screening protocols may not be sufficiently sensitive to detect all infectious window-period donations. JAMA. 2000;284:210-214- - - - - - - - - - ranking = 0.66666666666667keywords = antigen (Clic here for more details about this article) |
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