Long-term evaluation of HIV antigen and antibodies to p24 and gp41 in patients with hemophilia. Potential clinical importance

Neutralizing antibodies as a prognostic indicator in the progression of acquired immune deficiency syndrome (AIDS)-related disorders: a double-blind study

A double-blind longitudinal study for the presence of human immunodeficiency virus type 1 (HIV-1) neutralizing antibodies (NAb) in the sera of 36 patients with acquired immune deficiency syndrome (AIDS), 149 prodromal homosexual subjects, and 33 heterosexual subjects has been carried out. All AIDS patients and 68% of prodromal homosexual subjects (101/149) were found to be HIV-1 antibody positive by Western blot assay. All heterosexual subjects were HIV-1 antibody negative. Neutralizing antibody(s) was determined by testing the protective activity of sera against HIV-1 infection of human T-cell line H9. Study subjects were divided into NAb(+) (antibody titer, greater than 1:40) and NAb(-) (antibody titer, less than 1:40) groups. During the 24-month observation period 2 of 80 (3%) HIV-1(+) NAb(+) individuals progressed to AIDS and died, as compared to 5 of 21 (24%) of HIV-1(+) NAb(-) subjects who progressed to AIDS. Similarly, among the NAb(+) AIDS patients 8 of 23 (35%) died, while 10 of 13 (77%) of the NAb(-) patients died during the course of the study. In addition, the absence or reduction of HIV-1 p17 and p24 antibodies directed against HIV-1 antigens as well as the low titer or absence of NAb appears to be closely related to the clinical progression of the disease. These studies suggest that a decrease in the virus neutralization capacity of the sera and a decrease or complete loss of HIV-1 p17 and p24 antibodies may be useful as prognostic indicators for the progression of disease in HIV-1-seropositive patients.

Cellular immune response to viral peptides in patients exposed to HIV

In efforts to identify B cell and T cell epitopes of HIV-1 structural components, serum as well as lymphocytes from HIV-1-seropositive individuals were reacted with several recombinant and native peptides representing defined viral gag and env determinants. Several areas of discordance between humoral and cellular reactivity were identified. Specifically, the principal neutralizing site within HIV-1, the major envelope glycoprotein gp120, failed to elicit detectable cellular reactivities. The carboxyl portion of gp120 and the transmembrane gp41 region were uniformly recognized by patient antibodies but did not produce significant lymphocyte blastogenesis. However, the amino half of gp120 elicited cellular responses in a majority of the immunocompetent individuals tested, despite its extremely low reactivity with patient sera. Last, the major HIV-1 structure component p24 was found to be the most consistent T cell activation antigen among the panel tested.

A preliminary evaluation of five HIV antigen detection assays

Five commercial assays for detecting HIV antigen were evaluated using a panel of 40 coded samples in six laboratories. All assays were capable of detecting HIV-1 antigen (HIV-1 Ag), and are likely to prove useful for monitoring supernatant fluids from a variety of cell cultures. The concentration of HIV-1 protein which the assays detected varied from 25 ng/ml down to 25 pg/ml. Three of the five assays were also able to detect HIV-2 Ag. More extensive evaluations are needed to determine the sensitivity and specificity of these assays on serum samples and body fluids.

The problem of human immunodeficiency virus (HIV) infection and transplantation

The problem of human immunodeficiency virus (HIV) infection and that of the acquired immunodeficiency syndrome (AIDS) are becoming increasingly important in clinical transplantation. The epidemiologic characteristics of this infection are important factors in determining the impact of this infection on transplant patients: in particular, the presence of a transmissible virus in the blood, tissues, and body fluids of even asymptomatic individuals for prolonged periods; the role of lymphocyte activation in accelerating the pace and effects of HIV infection, with the transplant patient having more reasons for lymphocyte activation than other patient categories; and the possible contributions of immunosuppressive therapy to the course of HIV infection. Already, at least 20 cases of primary HIV infection conveyed by infected blood or allografts at the time of transplant have been noted; a similar number of transplants have been carried out in asymptomatic carriers of the virus. The initial impression is that the course of HIV infection in these patients is accelerated, but information is incomplete and an international registry for the study of this problem has been established.