View clinical trials related to HIV Infections.
Filter by:The factors that influence HIV disease progression are not well understood. While larger amounts of circulating virus (high 'viral loads') predict future adverse clinical events, many of the clinical factors responsible for high viral loads and disease progression remain unknown. Certain clinical events and defined interventions are associated with increases in plasma viral RNA concentrations. One of these clinical interventions is immunization; immunization with several vaccines have been shown to increase plasma HIV RNA concentrations. Even though vaccination can lead to transient increases in plasma HIV concentrations, certain vaccines, including influenza vaccine, are still recommended for HIV patients because the risks of the disease targeted by the immunization are held to be greater than the immunization itself. Therefore, immunization with influenza vaccine can be considered a model, clinically indicated intervention, given at a known time which stimulates HIV replication. For influenza immunization, and for other treatments leading to increases in viral RNA concentrations is not available. We hypothesize that immunization with influenza vaccine, and perhaps other immune stimulatory events, lead to an increase in HIV replication through a regulatory system involving cytokines, signal transduction systems, transcription factors, effects on the cell cycle, and increased expression of additional gene products needed for viral replication, such as genes of the nucleic acid biosynthetic pathways. While experiments aimed at investigating one or another particular part of this regulatory system can be performed with traditionally available technologies, such technologies cannot provide comprehensive information concerning a large number of the regulatory events that may be involved in mediating the increase in HIV RNA concentration. In this protocol, we aim to develop the methodologies needed to determine changes in expression of many of the genes which may be involved in mediating the regulation of HIV expression in HIV-infected patients using cDNA microarray technologies. Once the methodologies are developed, such work may provide new insights into the regulatory systems controlling HIV expression in HIV-infected patients may provide new insights into the pathogenesis of HIV disease.
This study will examine how quickly white blood cells called CD4 lymphocytes reproduce and how long they live in people infected with HIV. It will do this using bromodeoxyuridine (BrDU), a compound that is structurally similar to thymidine, one of the building blocks of DNA. BrDU gets incorporated into DNA instead of thymidine, but it can only get into cells that are replicating. Therefore, measuring the proportion of cells with BrDU indicates how many cells are replicating. HIV-infected patients 18 years of age and older may be eligible for this study. Candidates will be screened with a medical history, physical examination, chest X-ray, electrocardiogram (EKG) and blood tests. Participants will be given an infusion of BrDU through a catheter (thin plastic tube) placed in an arm vein. Blood will be drawn up to 4 times in the first 24 hours after the infusion. Additional samples will then be collected as often as daily for the first week, twice a week for the next 3 weeks and then weekly to monthly for up to 1 year. Some patients may undergo a tissue biopsy (removal of a small tissue sample from a lymph node, tonsil or colon) or computed tomography (CT) scans of the thymus (a small gland between the lungs that manufactures lymphocytes. Some patients will have a second infusion in order to examine changes in the rate of CD4 replication over time or following potent antiretroviral therapy. Patients will be followed in the clinic periodically for the first year and then will be seen in the clinic or contacted by telephone once a year for 4 more years. The results of this study may provide a better understanding of how HIV causes disease and how therapy affects the immune system.
This study will evaluate the safety and immune system effects of infusing HIV-infected patients with multiple doses of lymphocytes (white blood cells) from their non-infected identical twin. It will determine whether the donated lymphocytes can improve immune function and reduce viral load in the infected twin. Identical twin pairs-one who is infected with HIV-1 and one who is negative for the virus-may be eligible for this study. Candidates will be screened with blood tests, a medical history and physical examination. Both twin participants will receive a tetanus booster shot, if needed. The non-infected twin will undergo apheresis to collect white blood cells. For this procedure, whole blood is collected, similar to the procedure for donating a unit of blood from a needle in the arm. The blood flows through a cell separator machine where the white cells are removed, and the rest of the blood (red cells, plasma and platelets) is returned to the donor through a catheter in the opposite arm. The collected lymphocytes will be given intravenously (through a vein) to the infected twin over a 60-minute period. This procedure-apheresis and infusions-will be repeated 4 days a week to complete one cycle. The cycles will be repeated about every 8 weeks for 6 cycles (about 1 year). The infected twin will have blood samples drawn on the first day of each cycle, 2 weeks after the beginning of each cycle, and 4 weeks after each cycle to evaluate immune status, viral load and other safety parameters. The frequency of these blood tests may change as the study progresses. The infected twin will also undergo apheresis immediately before each cycle of infusions and one month later to test the white cells for certain immune features. The number of apheresis procedures may be reduced as the study proceeds.
Invasive aspergillosis is a fungal disease which is increasing in incidence with the increase in immunocompromised persons in our population. Persons with prolonged neutropenia secondary to cytotoxic chemotherapies are at the highest risk for acute aspergillosis. Patients undergoing bone marrow transplantation, receiving prolonged corticosteroid or other immunosuppressive therapies, and persons with HIV infection and AIDS are also at risk. Even with antifungal therapy, aspergillosis in its acute invasive forms has a high mortality. In bone marrow transplantation patients and in those whose infection involves the brain, this mortality is greater than 90%. Amphotericin B in its conventional form, is the current standard treatment for this disease. Response to therapy with amphotericin B usually ranges between 20-60% in most studies. The higher response rates are usually seen in those patients who can tolerate this agent for at least 14 days. Because of its nephrotoxicity and other adverse effects, alternatives to conventional amphotericin B have been sought. These currently include liposomal forms of amphotericin B and itraconazole. Although these forms show a decrease in adverse effects, the efficacy of these drugs has not been shown to be equivalent to conventional amphotericin B. Voriconazole is an investigational antifungal drug currently being brought to phase III trials in the US. This azole has been shown active against Aspergillus spp. in vitro, and in animal models and early human trials to be effective against aspergillosis. It has been shown to be well-tolerated and is available in an intravenous and oral formulation. This study will evaluate the efficacy, safety, and toleration of voriconazole compared to conventional therapy with amphotericin B as primary treatment of acute invasive aspergillosis in immunocompromised patients. Patients will be randomized to open-labelled therapy with voriconazole or amphotericin B in a one-to-one ratio.
This study will try to define how and where HIV infection persists in the body by determining: 1) if there are cells where HIV can live for long periods of time without being seen and destroyed by the immune system; 2) if there are sites where anti-HIV drugs cannot penetrate enough to stop new HIV replication; and 3) if HIV in certain lymph nodes can remain infectious for prolonged periods of time. It will also explore whether immune system damage caused by HIV can be repaired after new virus replication is stopped with treatment. HIV-infected patients 18 years of age and older may be eligible for this study, which will include three groups as follows. Candidates will be screened with a medical history, physical examination, blood and urine tests and possibly chest X-ray and electrocardiogram. Participants will be divided into three groups according to CD4 count levels: > 500 cells/microliter of blood; between 300 and 500 cells/microliter, and < 300 cells/microliter of blood. All participants will be treated with a combination of four antiretroviral drugs: indinavir, zidovudine, lamivudine and nevirapine. (Exceptions to this regimen may be made in certain circumstances for patients who cannot tolerate one of the four drugs.) In addition, they will undergo the following procedures: Blood tests - Blood tests will be done at screening and at study entry to evaluate the patient's health status and measure CD4 T cell count and plasma HIV levels; at the beginning of treatment to look for drug-related side effects; and during the course of the study to evaluate drug effectiveness in inhibiting HIV replication; CD4 T cell levels and function. Lymph node biopsy - Lymph node biopsies are done under local anesthesia. A small incision is made, the node is removed, and the incision is closed with stitches. Up to two nodes may be removed during each procedure. Patients with CD4 counts greater than 500 cells/microliter of blood and those with counts less than 300 cells/microliter will have three lymph node biopsies in order to 1) assess the effectiveness of therapy in inhibiting HIV replication in the nodes (the major site of replication); 2) determine how long HIV-infected cells may persist in the nodes after new replication is stopped by therapy; and 3) determine if immune damage caused by HIV can be repaired when virus replication is stopped. Lymph node biopsy in patients with counts between 300 and 500 cells/microliter of blood is required only at baseline, although follow-up biopsies are encouraged. Leukapheresis - In this procedure, whole blood is collected through a needle placed in an arm vein. The blood circulates through a cell separator machine where the white cells are removed and collected. The rest of the blood is returned to the body, either through the same needle used to draw the blood or through a second needle placed in the other arm. The collected white cells are used for special studies of the level and function of T cells before and after drug treatment. Patients with CD4 counts > 500 cells/microliter and < 300 cells/microliter will undergo leukapheresis up to four times - at study entry and about 2, 6 and 12 months after starting antiretroviral therapy. Patients with CD4 counts between 300 and 500 cells/microliter will have this procedure either at study entry and 6 and 12 weeks after initiation therapy, or on the same schedule as the other patients.
This study will investigate whether medication for cytomegalovirus (CMV) retinitis-a viral infection of the eye-can safely be stopped in HIV-infected patients whose immune function has improved from anti-HIV therapy. Medicines taken to fight CMV infection (ganciclovir, foscarnet, and cidofovir) can cause serious side effects, such as low blood counts and kidney damage. Stopping these medications may, therefore, be beneficial. Patients with HIV infection who develop CVM retinitis usually have very low levels of infection-fighting white blood cells called CD4 cells-less than 50 cells per microliter of blood. New anti-HIV medications have been able to raise CD4 levels and improve immune function in many patients. This study will see if patients with CD4 levels above 150 cells per microliter can fight CVM retinitis without additional anti-CVM drugs. HIV-infected patients with CVM retinitis will have a physical examination and complete eye examination. These tests will be repeated after 2 weeks. If there is no evidence that the CMV infection has progressed, and if it is in a location that is not immediately sight-threatening, anti-CMV medications will be stopped. Patients will be examined every 2 weeks for 3 months and then every 3 weeks for the next 3 months. Patients whose CD4 count has remained above 100 after 6 months will continue to be followed every 4 weeks until the CVM infection becomes active again. At that time, anti-CVM medicines will be re-started. Patients will also have blood and urine samples taken to test for levels of HIV and CMV in the blood and urine, and will be interviewed about their vision and how it affects daily activities.
Virus present in semen likely contributes substantially to the sexual transmission of HIV. However, the source of HIV in semen is unknown. Some evidence suggests that the prostate may be the source of at least some of the virus in semen. This study is designed to determine whether the prostate may serve as the source of virus in semen by comparing the concentration of HIV-1 RNA in semen donated normally, in semen obtained following prostatic massage, and in expressed prostatic secretions. Finding a source for semen HIV would provide important insights into several aspects of HIV sexual transmission. Since some drugs do not enter the prostate well, the finding that virus is produced in the prostate might suggest the prostate could serve as a reservoir for HIV, leading to the development of resistance to antiviral agents.
Non-Hodgkin's lymphoma (NHL) is the third most rapidly increasing cancer in the United States. HIV-related NHL is responsible for some of the increase since the early 1980s. However, it cannot explain the steady increase in the incidence rates in earlier years, nor the entire increase shown recently. A possible role of environmental exposures is receiving attention. One possibility is that exposure to organochlorines (OCs) may be related to the occurrence of NHL. NCI is currently designing a large population-based case-control study to investigate this hypothesis further by analyzing OC levels in blood collected at the time of interview from cases of NHL and their matched controls. At the time of these interviews, cases in the main case-control study would most likely have already received chemotherapy. If chemotherapy changes the blood levels of OCs, this may lead to misclassification of exposure among cases and eventually to biased risk estimates. The purpose of this pilot study is to estimate the bias due to measuring the serum levels of OCs in cases during or after chemotherapy. Twenty newly diagnosed patients will be recruited for the study. From each patient, four consecutive blood samples, one prior to, two during, and one after chemotherapy, will be collected. Forty pairs of pre-existing cryopreserved serum samples (pre- and post-treatment) taken from the NHL patients who participated in an earlier NCI clinical study will also be included in this study. Samples will be assayed for OC levels. The results will be used to plan and to interpret another large case-control study (the main study).
This protocol presents the rationale, 25-year historical review, and methods for multidisciplinary, low-risk studies of individuals referred to the NCI Viral Epidemiology Branch (VEB). Referrals are generally for unusual types of cancer or related conditions, known, or suspected to be related to viruses. Kaposi's sarcoma in two homosexual men evaluated in 1981 is a classic example. These referral cases provide the basis for pilot studies that generate hypotheses, the development of protocols for formal investigations of promising leads, and help to set priorities for VEB. A VEB investigator who is a Staff Member at the NIH Clinical Center, interviews each subject, performs a physical examination, draws a blood sample, and, when appropriate for the disease or virus under study, obtains other clinically indicated biological specimens, such as urine, sputum, saliva, tears, semen, Pap smear, or cervical, anal, oral, or nasal swabs. On occasion, other relatively non-invasive studies may be indicated. Skin testing with conventional, licensed antigens for assessment of cellular immunity may be performed, and skin lesions may be biopsied or excised. Tumor or other tissue biopsies may be obtained when biopsy or surgery is clinically indicated for other reasons. Otherwise no surgery is performed, and no therapy is administered. Clinical referral to other components of NCI, NIH, or the private sector are made as needed. The biological specimens are frozen or otherwise preserved to be batch tested in current assays or future assays that will be developed. Such laboratory testing is performed either at VEB's own support laboratory, or collaboratively in other NCI, NIH, or extramural laboratories that have the needed expertise for the disease or virus under study. Occasionally, repeated or more long-term evaluation is required. More often, a single evaluation in the NIH outpatient clinic, or either at a collaborating physician's office or other suitable site in the field, is sufficient. The VEB investigator provides counseling relevant to the virus or disease under study, and about the interim study results. He or she makes appropriate referral if needed (e.g., to the Genetic Epidemiology Branch for genetic counseling). Clinically relevant results and the VEB investigator's interpretation of these results, are provided in writing to the subject's primary caregiver. Confidentially of the information that is obtained is carefully protected. The results of the study are summarized for publication in the peer review literature.
This is a placebo-controlled trial of intermittent fluconazole prophylaxis (200 mg orally three times a week) in the prevention of thrush.