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Biomedical subjects

H C Lane

Publications and source records attributed to H C Lane.

At least 109 records · Page 6Linked to original sources
PubMed1990

Increasing viral burden in CD4+ T cells from patients with human immunodeficiency virus (HIV) infection reflects rapidly progressive immunosuppression and clinical disease.

OBJECTIVE: To determine over time the relation between viral burden and immunologic decline in patients with asymptomatic human immunodeficiency virus (HIV) infection. DESIGN: Blind analysis of cell samples from matched cohorts for HIV proviral DNA by polymerase chain reaction, retrospective analysis of clinical data on patients, and prospective follow-up of patients seropositive for the human immunodeficiency virus type 1 (HIV-1). SETTING: National research clinic and academic medical centers. PATIENTS: Cohort 1 included 12 healthy HIV-1-seropositive patients (average follow-up, 14 months): Six patients had stable disease and 6 developed rapidly progressive disease. Cohort 2 included 15 healthy HIV-1-seropositive patients from the Multi-center AIDS Cohort Study (average follow-up, 32 months): Eight patients had stable disease and 7 developed rapidly progressive disease. LABORATORY STUDIES: Quantitative polymerase chain reaction was done to determine the HIV-1 viral burden in sort-purified CD4+ T cells obtained from patients at various timepoints. MEASUREMENTS AND MAIN RESULTS: In patients who remained asymptomatic, frequencies of HIV-infected CD4+ T cells were low (less than 1/10,000 to 1/1000) at study entry and increased only minimally (none higher than 1/1000). In contrast, among patients who developed HIV-related symptoms including the acquired immunodeficiency syndrome (AIDS) despite having similar CD4 counts, frequencies of HIV-infected CD4+ T cells were higher at entry (greater than 1/1000) and increased substantially (greater than 1/100) in most within 3 months of developing progressive disease. This increase in HIV burden coincided with a significant decline over time in the percent of T4 cells (31% to 16%), whereas the percent of T4 cells was unchanged in persons who remained asymptomatic (33% to 34%). CONCLUSIONS: Increasing viral burden in peripheral blood CD4+ T-cells is directly associated with a progressive decline in CD4+ T cells and deteriorating clinical course in HIV-infected patients.

CD4-Positive T-Lymphocytes↗
PubMed1990

Interferon-alpha in patients with asymptomatic human immunodeficiency virus (HIV) infection. A randomized, placebo-controlled trial.

STUDY OBJECTIVE: To evaluate the toxicity and clinical efficacy of interferon-alpha 2b (IFN-alpha) in patients with asymptomatic human immunodeficiency virus (HIV) infection. DESIGN: Randomized, placebo-controlled, and double-blind study. SETTING: Outpatient clinic of a government referral-based research hospital. PATIENTS: Volunteer sample of 34 patients with asymptomatic HIV infection who had CD4 counts of 400 cells/mm3 or more, positive peripheral blood mononuclear cell cultures for HIV, or p24 antigenemia. INTERVENTIONS: Patients were randomly assigned to receive either IFN-alpha or placebo, 35 x 10(6) units per day subcutaneously. Doses of IFN-alpha or placebo were modified according to predefined laboratory and clinical criteria. Therapy lasted at least 12 weeks. MEASUREMENTS AND MAIN RESULTS: Seventeen patients were randomly assigned to each group. The two groups had similar mean CD4 counts at study entry. Thirty-five percent of patients assigned to receive IFN-alpha withdrew from the study because of toxicity. The average daily dose of IFN-alpha was 17.5 x 10(6) units. All patients receiving IFN-alpha reported flu-like symptoms; other toxicities included granulocytopenia (55%) and elevated liver enzyme levels (45%). While receiving IFN-alpha, 7 patients (41%) became HIV culture negative (three or more consecutive negative peripheral blood mononuclear cell cultures taken at least 2 weeks apart). In contrast, 2 patients in the placebo group (13%) became culture negative while on study (P = 0.05). During the treatment period, CD4 lymphocyte percentages were sustained at or above the baseline level in patients receiving IFN-alpha and declined slightly in patients receiving placebo. Of the 32 study patients followed after study (range, 5 to 33 months), no patients in the IFN-alpha group developed an acquired immunodeficiency syndrome (AIDS)-defining opportunistic infection, compared with 5 patients in the placebo group (P = 0.02). CONCLUSIONS: Treatment of early-stage HIV infection with IFN-alpha can result in a decrease in frequency of viral isolation. Although its use may be accompanied by dose-dependent toxicities, IFN-alpha may have a role in slowing progression of HIV disease.

Adolescent↗
PubMed1990

Defective clonogenic potential of CD8+ T lymphocytes in patients with AIDS. Expansion in vivo of a nonclonogenic CD3+CD8+DR+CD25- T cell population.

This study examines the potential mechanism(s) responsible for the defective clonability of CD8+ T lymphocytes in patients with AIDS. By the combined use of one- and two-color fluorescence cytofluorometry we have shown an increase in the number of circulating DR+ cells due to the expression of DR on a relatively large proportion of T lymphocytes (one-third of CD3+ cells), the majority of them belonging to the CD8+ subset. In addition, the majority of CD8+DR+ cells in AIDS patients did not express CD25 Ag (the receptor for IL-2), a surface marker generally expressed on normal activated T lymphocytes. Sorted CD8+DR+ and CD8+DR- cell populations were analyzed comparatively for their ability to proliferate in response to different stimuli, including anti-CD3, anti-CD2, alone or in combination with anti-CD28 mAb and mitogens such as PHA, alone or in combination with PMA. We have demonstrated that CD8+DR+ cells were severely defective in their proliferative response to triggering via these major pathways of T cell activation even when an exogenous source of IL-2 or IL-4 was added to the microcultures 24 h after initiating the cultures. In contrast, CD8+DR- cells showed a significant proliferation in response to the different stimuli and the proliferative response was strongly enhanced by the addition of IL-2 or IL-4. At the end of the stimulation period CD8+DR+ and CD8+DR- proliferating populations were analyzed for CD25 Ag expression. Only 1 to 10% of CD8+DR+ cells expressed CD25 antigen compared with 40 to 50% of CD8+DR- cells. The proliferative defect of CD8+DR+ cells was further confirmed in experiments performed at the clonal level. The analysis of the frequency of proliferating T lymphocyte-precursors in both CD8+DR+ and CD8+DR- subsets showed that the defective clonogenic potential of CD8+ cells in AIDS patients could be in large part ascribed to CD8+DR+ cells. Five percent of CD8+DR+ cells showed a clonogenic potential compared to the 25% of CD8+DR- cells. Finally, we analyzed the surface expression of VLA-2 Ag, a marker of a chronic state of T cell activation, on circulating T lymphocytes. We have shown that a large proportion of CD3+DR+CD25- cells (50 to 80% in the different patients with AIDS analyzed) expressed VLA-2 Ag.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1990

The immunology of HIV infection.

A variety of immunologic abnormalities have been reported in patients with human immunodeficiency virus (HIV) infection. The most characteristic is a decrease in the number and function of CD4 helper/inducer T lymphocytes. Patients with HIV infection also have abnormalities in the number and activity of CD8 suppressor/cytotoxic T lymphocytes, defective soluble antigen recognition, polyclonal B cell activation, and decreased cytotoxicity. The CD4 cell defect is the most critical abnormality in the immunopathogenesis of HIV disease. Understanding the relationship of this defect to the appearance of clinical problems can contribute to the management of patients with HIV infection.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Effects of interferon-alpha in patients with AIDS-associated Kaposi's sarcoma are related to blood interferon levels and dose.

Definition of improved therapeutic regimens of interferon-alpha (IFN-alpha) for the treatment of Kaposi's sarcoma (KS) would be useful since currently recommended doses are sometimes associated with unacceptable toxicity. IFN concentrations were measured in serum samples from men with AIDS-associated KS who were enrolled in a trial of IFN-alpha alone (16 patients) or a trial of IFN-alpha combined with zidovudine (25 patients). Analyses were done to examine the relationship between the dose of IFN-alpha, blood level of IFN, and the patient's clinical response to treatment. There was no correlation between dose of zidovudine given and response. As expected, there was a high correlation between dose of IFN-alpha and blood level in both studies (p less than 0.001). Furthermore, we found relationships between clinical response and both dose of IFN-alpha and blood level achieved. In the two studies combined, among men with greater than 200 CD4+ cells/mm3 of blood at baseline on average daily doses of greater than or equal to 10 million international units (MIU) of IFN-alpha, 13/19 (68%) responded compared to 6/17 (35%) on less than MIU (p = 0.05). Similarly, of men with IFN blood levels greater than or equal to 100 IU/mL 12/16 (75%) responded compared to 7/20 (35%) of those with blood levels less than 100 IU/mL (p = 0.02). The dose and blood levels of IFN achieved and maintained may be important factors in determining responses of KS. Additional clinical trials of IFN-alpha treatment of KS at doses about 10 MIU/day appear warranted.

Acquired Immunodeficiency Syndrome↗
PubMed1990

CD8+ T lymphocytes of patients with AIDS maintain normal broad cytolytic function despite the loss of human immunodeficiency virus-specific cytotoxicity.

In this study, we have investigated the potential mechanisms responsible for the loss of human immunodeficiency virus type 1 (HIV-1)-specific cytolytic activity in the advanced stages of HIV-1 infection. We have demonstrated that HIV-1-specific cytotoxic T lymphocytes are predominantly contained within the CD8+DR+ subset. Furthermore, we have shown by a redirected killing assay that there is a dichotomy between HIV-1-specific cytolytic activity and broad cytolytic potential since the cytolytic machinery of CD8+DR+ cells is still functioning even in patients with AIDS who have lost their HIV-1-specific cytolytic activity. In addition, by comparative analysis of these two types of cytolytic activity over time we have demonstrated a progressive loss of HIV-1-specific cytolytic activity in the advanced stages of the disease, whereas the cytolytic potential remained unchanged regardless of the clinical stage. As previously shown in patients with AIDS, even in asymptomatic HIV-1-seropositive patients, CD8+DR+ cells from the same patient, compared to CD8+DR- lymphocytes, showed a substantial reduction in their ability to proliferate in vitro in response to different stimuli, such as mitogens (phytohemagglutinin and phorbol 12-myristate 13-acetate) and monoclonal antibodies directed against CD3, CD2, and CD28 molecules, and displayed a defective clonogenic potential. Thus, on the basis of these results we propose that the loss of HIV-1-specific cytolytic activity in HIV-1-infected individuals may result at least in part from a progressive decrease in the pool of HIV-1-specific cytotoxic T lymphocytes belonging to the CD8+DR+ subset whose ability to expand has been impaired.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Preferential infection of CD4+ memory T cells by human immunodeficiency virus type 1: evidence for a role in the selective T-cell functional defects observed in infected individuals.

CD4+ T cells of patients with AIDS exhibit a qualitative defect in their ability to respond to soluble antigen while their responses to mitogens remain normal. CD4+ T cells can be broadly divided phenotypically into "naive" [CD45RA+ (2H4+)] and "memory" [CD29+ (4B4+) or CD45RO+ (UCHL1+)] cell subpopulations, which represent distinct maturation stages. To determine the human immunodeficiency virus type 1 (HIV-1) infectability of memory and naive CD4+ T-cell subsets in vitro and to determine the in vivo preference of HIV-1 in these subpopulations, we obtained highly purified CD4+ T-cell subsets from normal and HIV-1-infected individuals and studied them by viral cultivation, quantitative polymerase chain reaction, and functional assays. Polymerase chain reaction studies demonstrated that the memory cell subset of CD4+ T cells is preferentially infected (4- to 10-fold more than naive T cells) by HIV-1 in vitro, and these memory cells are the principal reservoir for HIV-1 within CD4+ T cells obtained from infected individuals. Functional abnormalities attributable to CD4+ T cells in HIV-infected individuals (failure to respond in vitro to soluble antigen or to anti-CD3 monoclonal antibodies) were shown to reside primarily within these memory cells. Thus, the present study suggests that the selective functional defects present in the memory CD4+ T-cell subset of HIV-infected individuals may be a direct result of the preferential infection and consequently greater viral burden within these cells.

Antigens, CD↗
PubMed1990

Trimetrexate-leucovorin dosage evaluation study for treatment of Pneumocystis carinii pneumonia.

To determine the maximal tolerable dosage of trimetrexate for treatment of pneumocystis pneumonia, 25 patients were treated each day with 45 mg/m2 of trimetrexate and 80 mg/m2 of leucovorin; 10 received 60 mg/m2 and 80 mg/m2; 12 received 60 mg/m2 and 160 mg/m2; and 6 received 90 mg/m2 and 160 mg/m2, respectively. Leucovorin was increased twofold and trimetrexate reduced by 50% or suspended briefly for various levels of neutropenia and thrombocytopenia until blood counts increased. Dosage-modifying hematologic toxicity occurred in 12 (46%), 8 (80%), 9 (75%), and 4 (67%) patients with the respective groups. Cytopenias were in each case reversible and other toxicities were well tolerated. All survivors but one were able to receive a full 21 doses of trimetrexate. Twenty-four (92%), 10 (100%), 7 (58%), and 4 (80%) of patients in the respective groups survived. Thus, the 45 mg/m2/day dosage of trimetrexate with 80 mg/m2/day of leucovorin resulted in the least dosage-modifying toxicity and excellent efficacy. This combination should be selected for studies to compare trimetrexate with other therapies for pneumocystis pneumonia.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Synergistic effect of ganciclovir and foscarnet on cytomegalovirus replication in vitro.

Ganciclovir and foscarnet possess substantial activity against cytomegalovirus. Both exhibit dose-limiting toxicity, which reduces their clinical usefulness. We demonstrated synergistic inhibition of cytomegalovirus replication in vitro by ganciclovir and foscarnet. Reduced-dose combination therapy may provide a means to treat patients with cytomegalovirus infection while reducing drug toxicity.

Cytomegalovirus↗
PubMed1990

Virologic and immunologic aspects of acquired immunodeficiency syndrome.

From the initial clinical descriptions of the acquired immunodeficiency syndrome (AIDS) in 1981 to the present time, much has been discovered concerning the epidemiologic factors, pathogenesis, treatment and prevention of this disease. Recent advances in epidemiology have included a better understanding of the occupational risk of human immunodeficiency virus (HIV) infection after percutaneous exposure (responsible for approximately 0.4 per cent of instances), an appreciation of the potential variability in the time interval between infection and seroconversion (generally on the order of three months but occasionally longer) and establishment of the need for intimate contact to transmit infection. Following the discovery of HIV-1 as the etiologic agent of AIDS, many rapid advances have been possible including the development of screening tests, elucidation of the HIV-1 genome and the discovery that the CD4 T lymphocyte is the predominant cell destroyed by HIV-1. Progressive destruction of CD4 T cells results in a progressive decline in immunologic function that may take a variety of clinical forms, ranging from no symptoms to severe opportunistic infections. The delineation of the life cycle of HIV-1 has helped in the development of antiretroviral therapies, including agents that interfere with reverse transcription (nucleoside analogues, such as zidovudine, dideoxycytidine, dideoxyinosine and azidodideoxyuridine) and agents that interfere with viral assembly (protease inhibitors and interferon alpha). A more precise understanding of the nature of the immune response elicited after HIV-1 infection has resulted in the development of several candidate HIV-1 vaccines, including recombinant vaccinia viruses expressing the HIV-1 envelope and recombinant envelope proteins.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Acquired immunodeficiency syndrome.

The occurrence of unusual infections, in particular Pneumocystis carinii pneumonia and the rare neoplasm Kaposi's sarcoma, in previously healthy homosexual men in the late 1970s heralded the epidemic of human immunodeficiency virus infection, the most severe form of which is the acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1990

The role of antiretroviral therapy in living long and living well.

We have seen a dramatic increase in the types of antiviral strategies and numbers of specific antiviral agents that have emerged since the early 1980s when infection with the human immunodeficiency virus was first recognized. At the moment, zidovudine is the only drug approved by the FDA for treatment of HIV infection, and its indication is limited only to patients in the most advanced stages of immunodeficiency. Although zidovudine cannot "cure" HIV infection, it can significantly delay the seemingly inexorable course of immune system decline and buy some meaningful time for most HIV-1 infected patients, whether or not they have developed immunodeficiency. Other agents such as interferon alpha and the didoxynucleoside analogues, ddI and ddC, have also shown promise as antiretroviral agents, and it is hoped they will be proved, in the near future, capable of delaying the progression of immune system destruction by HIV-1. Other related treatment modalities such as the use of PCP prophylactic regimens also have succeeded in decreasing the incidence of opportunistic infections and thereby improving survival. It is likely that future strategies will involve the use of alternating, multidrug regimens both to reduce selective pressure for the development of drug resistance and to minimize the toxicity of single-agent therapy. The sum of these developments has been to change the prognosis of HIV infection. A disease once viewed as an automatic death warrant is now in the process of becoming a chronic, potentially long-term treatable illness.

Acquired Immunodeficiency Syndrome↗
PubMed1989

NIH conference. Pneumocystis pneumonia: from bench to clinic.

Pneumocystis carinii is an intriguing organism found almost exclusively in the lungs. Very little is known about this organism's biologic or epidemiologic character. Over the past two decades, P. carinii has been recognized with increasing frequency as a cause of pneumonia in cancer patients, transplant recipients, and patients infected with the human immunodeficiency virus (HIV). With the increased number of cases of P. carinii pneumonia and a greater emphasis on studying this organism, sophisticated immunologic, metabolic, and molecular biologic tools have ben applied to enhance diagnosis, therapy, and prevention. Immunologic studies have identified specific antigens of human P. carinii, resulting in the development of new diagnostic tests and more specific serologic data. Metabolic studies have allowed screening and identification of new therapeutic and preventive drugs. The development of nucleic acid libraries has allowed enzymes and other proteins to be elaborated in large quantities, facilitating a wide range of studies. These new techniques have changed and will continue to change the ways that pneumocystis pneumonia is diagnosed, treated, prevented, and understood.

Acquired Immunodeficiency Syndrome↗
PubMed1989

The reservoir for HIV-1 in human peripheral blood is a T cell that maintains expression of CD4.

Human immunodeficiency virus type 1 (HIV-1) selectively infects cells expressing the CD4 molecule, resulting in substantial quantitative and qualitative defects in CD4+ T lymphocyte function in patients with acquired immunodeficiency syndrome (AIDS). However, only a very small number of cells in the peripheral blood of HIV-1-infected individuals are expressing virus at any given time. Previous studies have demonstrated that in vitro infection of CD4+ T cells with HIV-1 results in downregulation of CD4 expression such that CD4 protein is no longer detectable on the surface of the infected cells. In the present study, highly purified subpopulations of peripheral blood mononuclear cells (PBMCs) from AIDS patients were obtained and purified by fluorescence-automated cell sorting. They were examined with the methodologies of virus isolation by limiting dilution analysis, in situ hybridization, immunofluorescence, and gene amplification. Within PBMCs, HIV-1 was expressed in vivo predominantly in the T cell subpopulation which, in contrast to the in vitro observations, continued to express CD4. The precursor frequency of these HIV-1-expressing cells was about 1/1000 CD4+ T cells. The CD4+ T cell population contained HIV-1 DNA in all HIV-1-infected individuals studied and the frequency in AIDS patients was at least 1/100 cells. This high level of infection may be the primary cause for the progressive decline in number and function of CD4+ T cells in patients with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Zidovudine in patients with human immunodeficiency virus (HIV) infection and Kaposi sarcoma. A phase II randomized, placebo-controlled trial.

STUDY OBJECTIVE: To evaluate the toxicity, effects on immune function, antitumor effects, antiretroviral effects, and pharmacokinetics of zidovudine therapy in patients with early human immunodeficiency virus (HIV) infection and Kaposi sarcoma. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: National Institutes of Health, a referral-based research institution (single site). PATIENTS: Physician-referred volunteer patients with HIV infection, Kaposi sarcoma, CD4+ lymphocyte counts greater than 0.2 x 10(9)/L, and no systemic symptoms or history of opportunistic infection. Of 41 patients enrolled, 4 had not met all entry criteria and were therefore not evaluable. INTERVENTIONS: Patients were randomized to one of four treatment groups for an initial 12-week treatment period: oral placebo (9 patients); zidovudine, 250 mg orally every 4 hours (9 patients); zidovudine, 0.5 mg/kg body weight intravenously every 4 hours (9 patients); and zidovudine, 2.5 mg/kg intravenously every 4 hours (10 patients). After at least 12 weeks of therapy at their assigned dose, patients were treated with oral zidovudine, generally 250 mg every 4 hours, with a mean 42-week follow-up. MEASUREMENTS AND MAIN RESULTS: Anemia and granulocytopenia were the major toxicities. Significant increases in platelet counts and declines in serum HIV antigen and IgG and IgM levels occurred in treated patients. Treated patients were more likely than those on placebo to clear HIV from the cerebrospinal fluid. There were no differences in tumor progression or CD4+ or CD8+ lymphocyte counts among the groups. CONCLUSIONS: Zidovudine was well tolerated and had antiretroviral activity in patients with early HIV infection and Kaposi sarcoma but it had no significant effect on the extent of Kaposi sarcoma or on immune function.

Acquired Immunodeficiency Syndrome↗
PubMed1989

A phase I trial of recombinant human interferon-gamma in patients with Kaposi's sarcoma and the acquired immunodeficiency syndrome (AIDS).

A Phase I study of recombinant interferon-gamma (rIFN-gamma) was conducted to determine the toxicity and pharmacokinetics of this lymphokine in acquired immunodeficiency syndrome (AIDS) patients with Kaposi's sarcoma (KS). Sixteen patients with AIDS/KS were entered into a fixed-dose trial at either 0.001, 0.01, 0.1, or 1.0 mg/m2 of rIFN-gamma. rIFN-gamma was initially administered either as a single 24-hr continuous iv infusion or as a single im injection, followed 4 days later by a 10-day course of daily therapy by the same route. Following a 1-week washout period, this sequence of administration was then repeated, with the drug given by the alternate route. Pharmacokinetic analysis of the 1.0-mg/m2 group revealed that peak serum levels of up to 153 U/ml occurred 2-4 hr after im injection and that steady-state levels of up to 40 U/ml were reached approximately 7-12 hr after beginning iv infusion. Dose-related toxicities in this trial included fever, headache, fatigue, nausea, and hepatitis, all of which were most severe at the two highest doses. Dose-dependent depression of the total white blood-cell (WBC) count, affecting both granulocytes and lymphocytes, was the most common laboratory abnormality. Natural killer (NK)-cell activity was slightly enhanced at a dose of 0.1 mg/m2 but suppressed at 1.0 mg/m2 of drug; monocyte-mediated cytotoxicity, in contrast, was significantly increased only at the highest dose. No dose-related changes were noted in KS lesions, HLA-DR expression by peripheral blood mononuclear cells, lymphocyte blastogenesis, or the ability to culture cytomegalovirus (CMV) from body fluids. We conclude that a maximally tolerated dose (MTD) for this drug is in the range of 0.1-1.0 mg/m2 and that at least modest evidence of systemic immunomodulation may be seen when rIFN-gamma is given at doses at or near this MTD.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Kaposi's sarcoma of the parotid gland in acquired immunodeficiency syndrome.

A patient with acquired immunodeficiency syndrome complained of a dry mouth and bilateral swelling of the parotid glands. Kaposi's sarcoma (KS) was found within the tissue of the parotid gland. Although KS is a common manifestation of acquired immunodeficiency syndrome, the presence of KS in the salivary glands is very rare. The human immunodeficiency virus I (HIV-I) genome was not identified in parotid glandular cells or in KS cells in this case, although the virus was detected in infiltrating lymphocytes and in tissue macrophages.

Acquired Immunodeficiency Syndrome↗