Characterization of immunologic function in homosexual men with persistent, generalized lymphadenopathy and acquired immune deficiency syndrome

Casp8p41 expression in primary T cells induces a proinflammatory response

OBJECTIVE

HIV infection of CD4 T cells can lead to HIV protease-mediated cleavage of procaspase 8 generating a novel, HIV-specific peptide called Casp8p41. Casp8p41 has at least two biologic functions: induction of cell death via mitochondrial depolarization and release of cytochrome C, as well as activation of nuclear factor kappa B (NFkappaB). We have previously shown that Casp8p41-induced NFkappaB activation enhances HIV LTR transcription and consequently increases HIV replication. Herein, we questioned whether Casp8p41-induced NFkappaB activation impacts the cytokine profile of cells expressing Casp8p41.

DESIGN

Analysis of cells expressing Casp8p41 and HIV-infected T cells.

METHODS

We assessed whether host genes are transcriptionally activated following Casp8p41 production, using microarray analysis, cytokine quantification, followed by western blot and flow cytometry.

RESULTS

Microarray analysis identified 259 genes significantly upregulated following expression of Casp8p41. Furthermore, Casp8p41 expression in primary CD4 T cells results in increased production of interleukin (IL)-2, IL-15 and tumor necrosis factor (TNF), as well as IL-1RA; whereas levels of granulocyte macrophage colony-stimulating factor and interferon (IFN)-gamma were reduced in the Casp8p41 expressing cells. Intracellular flow cytometry confirmed the co-association of Casp8p41 with elevated TNF in HIV-infected cells.

CONCLUSION

These data indicate that the expression of Casp8p41 in HIV-infected CD4 T cells in addition to promoting apoptosis and enhancing HIV replication also promotes a proinflammatory cytokine milieu, which is characteristic of untreated HIV infection.

Effect of protease therapy on cytokine secretion by peripheral blood mononuclear cells (PBMC) from HIV-infected subjects

The viral load reduction seen in patients with late stage HIV infection treated with the protease inhibitor, ritonavir, is accompanied by increases in the in vitro proliferative responses generated by PBMC. The present study was undertaken to investigate which lymphocyte subsets generated these responses and the effects of therapy on cytokine production. Lymphoproliferation following phytohaemagglutinin (PHA) stimulation was studied by thymidine incorporation, and production of IL-2, interferon-gamma (IFN-gamma) and IL-4 was assessed by ELISA in 12 patients receiving ritonavir and seven receiving placebo in the context of randomized, blinded clinical trials. CD4+ cell-depleted and CD8+ cell-depleted subsets were obtained from PBMC by immunomagnetic bead depletion. At week 4 of therapy a two-fold or greater increase in proliferative responses was observed in 9/12 subjects receiving therapy, compared with 0/7 receiving placebo. Similarly there was a significant increase in IL-2 and IFN-gamma production of 2.7-fold (P = 0.02) and 1.7-fold (P = 0.03), respectively, in the treatment group compared with those receiving placebo. No change in IL-4 production was observed. Despite these increases, cytokine responses post-therapy were still reduced compared with both healthy controls and asymptomatic HIV-infected subjects. Increases in proliferative response and IL-2 production were greater in the CD8+ cell-depleted population than in the CD4+ cell-depleted population, whereas increases in IFN-gamma production were derived from the CD4+ cell-depleted population.

Lack of in vitro anti-gp160 antibody production is a correlate of nonprogression among HIV type 1-infected individuals

The aim of our study was to investigate the possible correlation of in vitro antibody production (IVAP) directed to the gp160 protein of HIV-1 with CD4+ slopes, plasma viremia, and disease progression in long-term nonprogressors (LTNPs). Nineteen subjects with a long-term nonprogressive HIV-1 infection were studied and followed for 2 years. During the follow-up, in vitro anti-gp160 producers showed negative CD4+ slopes in the majority of cases (9 of 12), whereas 5 of 7 nonproducers showed positive CD4+ slopes. Plasma viremia values, which were not significantly different in the two groups at baseline, became significantly higher in anti-gp160 producers when compared with nonproducers during the follow-up (p = 0.012). Finally, a trend toward progression was observed in the group of producers but not in nonproducers. These findings suggest that the in vitro production of anti-gp160 antibodies by peripheral B cells is not a correlate of protection, and may represent an early predictor of progression in LTNPs.

Selective compartmental dominance: an explanation for a noninfectious, multifactorial etiology for acquired immune deficiency syndrome (AIDS), and a rationale for ozone therapy and other immune modulating therapies

The most widely accepted etiological explanation for acquired immune deficiency syndrome (AIDS) currently invokes an infectious model involving the human immunodeficiency virus (HIV). Because this infectious model has failed to meet any conventional criteria for establishing microbial causation, this theory still relies on the high, though not perfect, statistical correlation linking presence of HIV antibodies with patients diagnosed with, and at risk for the syndrome. Many scientists and clinicians now doubt the HIV theory, though, and propose instead a multifactorial causation similar to that seen in cancer and heart disease. In order to discard the HIV model, however, it is necessary to explain the high statistical correlation mentioned above. Recent studies involving cellular mediated immunity and cytokine modulation may explain this statistical relationship without the need to invoke infectious causation, by suggesting certain functional characteristics and feedback loops in the immune system which the author calls selective compartmental dominance (SCD). SCD provides a model in which chronic dominance of the humoral immune compartment secondary to chronic high-dose antigenic challenge results in chronic suppression of the cellular immune compartment. This model predicts that even HIV-negative members of the risk groups are susceptible to AIDS, assigns no special causal role for HIV in AIDS, and suggests a rational course of nontoxic therapy that can potentially reverse cases in the earlier stages.

Induction of interleukin-1 and glucocorticoid hormones by HIV promotes viral replication and links human chromosome 2 to AIDS pathogenesis: genetic mechanisms and therapeutic implications

Human immunodeficiency virus may regulate its replication by stimulating the synthesis of interleukin-1. Interleukin-1, in turn, has the ability to stimulate the human immunodeficiency virus enhancer region. The human genes responsible for interleukin-1 and interleukin-1 receptor antagonist synthesis are located on the long arm of chromosome 2. Coincidentally, the trans-activation responsive ribonucleic acid element in the R region of the long terminal repeat of human immunodeficiency virus-1 has been found to interact directly with a factor present on the long arm of chromosome 2 to facilitate transactivation by the human immunodeficiency virus Tat protein. The human CD26 gene is also located on the long arm of chromosome 2. CD26 is a lymphocyte cell surface antigen that is stimulated by interleukin-1 and serves with CD4 as a coreceptor that interacts with the V3 loop in gp120 of human immunodeficiency virus. The human immunodeficiency virus-induced interleukin-1 excess, thus, serves human immunodeficiency virus by enhancing replication, and by increasing human immunodeficiency virus infectivity via activation of CD26. IL-1 also adversely affects acquired immune deficiency syndrome-related Kaposi's sarcoma. Several genetic treatments for human immunodeficiency virus infection are proposed.

Antiviral activity of biological response modifiers in a murine model of AIDS. Requirement for augmentation of natural killer cell activity and synergy with oral AZT

We employed the Rauscher murine leukemia virus (RMuLV) as a murine retrovirus model of AIDS, to test biological response modifiers (BRM) and antiviral agents for potential therapeutic activity against the human immunodeficiency virus (HIV). We examined the relationship between the augmentation of natural killer (NK) cell activity and antiviral efficacy of a series of BRM, most of which are known inducers of interferon, in this model. Poly [I,C]-LC, MVE-2, and CL 246,738, but not Ampligen, soluble glucan, or 7-thia-8-oxoguanosine, consistently produced antiviral activity. In addition, the combination of suboptimal doses of oral 3'-azido-3'-deoxythymidine (AZT) (in drinking water) and poly [I,C]-LC produced a synergistic antiviral effect. With all the BRM tested, a consistent pattern emerged, namely that antiviral activity always correlated with the augmentation of splenic NK cell activity in infected animals. For instance, poly [I,C]-LC boosted NK activity much more in infected mice treated therapeutically (treatment initiated after infection) than prophylactically (treatment initiated before infection), and it had greater antiviral activity therapeutically than prophylactically. For the BRM tested, antiviral activity did not occur without augmentation of NK activity in infected mice. In contrast, augmentation of NK activity in uninfected mice bore no relationship to antiviral activity. Furthermore, elimination of NK cells by treating mice with anti-asialo GM1 abolished the antiviral activity of poly [I,C]-LC. Although splenic NK activity was ablated by anti-asialo GM1, serum interferon levels were not affected by this treatment. These results point to a causal connection between the augmentation of NK cell activity and the antiviral efficacy of these BRM in this murine AIDS model. NK cells thus appear to play a key role in resistance to this retrovirus, as has been suggested for HIV.

In vitro anti-HIV-1 antibody production in subjects in different stages of HIV-1 infection

We evaluated the in vitro antibody production from peripheral blood mononuclear cells (PBMC) against HIV-1 proteins in infected adults. Fifty-four HIV-1 infected patients (four recent seroconverters, 15 asymptomatics with a CD4 count higher than 500/microliters, 27 asymptomatics with a CD4 count between 200 and 500/microliters and eight symptomatic patients) were tested. PBMC were incubated in the presence or absence of 1% pokeweed mitogen (PWM) at 37 degrees C for 8 days. Western blot assay, p24 antigen ELISA and anti-p24 antibody ELISA were performed on serum and culture supernatants. Spontaneous production of anti-env antibody in culture supernatants was evidenced in all subjects. All the positive supernatants for anti-core antibodies (18/54) were derived from asymptomatic patients. PBMC from recent seroconverters and from symptomatic patients did not produce any anti-core antibody. Antibody production decreased after stimulation with PWM. The concentration of p24 antigen did not significantly increase in p24 positive supernatants following acidification (P = 0.1), suggesting that the inability to detect p24 antibody was not due to the anti-p24 antibody complexed to p24 antigen in culture supernatants. In vitro production of anti-p24 antibodies was significantly more frequent in asymptomatic subjects with high CD4+ cell counts (P = 0.02) and was absent in recent seroconverters. This last finding suggests that during the initial phases of the infection, anti-p24 antibody production may be restricted to cells residing in lymphoid organs. In addition, the lower percentage of anti-core antibody in people with low CD4+ cell counts is not merely a consequence of the binding of the antibody to an increased amount of antigen, but probably reflects an impaired production or a sequestration of producing cells in lymphoid tissue during the late stages of the infection.

Blood zinc status and zinc treatment in human immunodeficiency virus-infected patients

We investigated the zinc concentration in blood and the effect of zinc supplementation in 11 male outpatients seropositive for human immunodeficiency virus at stage 5 according to the Walter Reed classification. Zinc concentration was measured in serum, platelets, mononuclear and polymorphonuclear cells, and erythrocytes. There was a significant increase in serum zinc concentration after zinc administration, but the zinc level in blood cells remained unchanged. All patients showed a progressive gain in body weight and a slight elevation in levels of CD4+ cells. No adverse side-effects were noticed.

p24 antibody production in p24 antibody-negative HIV-infected subjects

To determine if HIV-infected patients with no detectable serum antibodies to p24 are producing antibodies to p24 (anti-p24), blood was obtained from 49 HIV-infected patients at various stages of infection. Serum p24 antigen levels were measured and peripheral blood mononuclear cells were cultured for 1 week without mitogenic stimulation. The presence of anti-p24 in culture supernatants and sera was determined by radioimmunoprecipitation assays. Cells from 89% of the patients who had anti-p24 in their sera spontaneously synthesized anti-p24 in vitro. Similarly, cells from 83% of the HIV-infected patients who had no detectable anti-p24 in their sera spontaneously produced anti-p24 in vitro. Thus the absence of anti-p24 in serum did not reflect suppression in the ability of patients' cells to synthesize and secrete antibodies to p24. However, cells from patients whose sera contained anti-p24 spontaneously synthesized more anti-p24 than did cells from patients whose sera lacked anti-p24, suggesting that these two groups of patients may represent individuals with inherently high or low responses to p24 epitopes, respectively.

Proliferative response of mononuclear cells from HIV-infected patients to B-cell mitogens: effects of lymphocyte subset frequency, T-cell defects and prostaglandins

Proliferative responses of mononuclear cells from patients seropositive for human immunodeficiency virus to B-cell mitogens are severely depressed compared with those of controls. The role of several immunoregulatory phenomena was analyzed. Experimental results show that addition of exogenous lymphokines to cultures increases responses to anti-mu and SAC. Addition of indomethacin to cultures greatly increases the SAC response and causes a smaller increase in the pokeweed mitogen (PWM) response. When both exogenous lymphokines and indomethacin are present in cultures, responses of patients' cells to all three mitogens are positively correlated with the percentage of CD4+ T cells and negatively correlated with the percentage of CD8+ T cells. Responses to anti-mu and SAC are also positively correlated with the percentage of B cells in these cultures. On the basis of these correlations between B-cell responses and lymphocyte subset frequency, patients' B-cell responses can be mathematically corrected to estimate the responsiveness of the B cells in the presence of normal numbers of CD4+ and CD8+ cells. These corrected responses for all three mitogens are virtually identical to control responses. Furthermore, responses of enriched B-cell populations from HIV+ subjects and normal controls to SAC were not significantly different when assays were performed in the presence of indomethacin and exogenous lymphokines. These results suggest that B cells from HIV+ patients are inherently normal in their responsiveness to B-cell mitogens. The depressed function is imposed upon them as a result of the abnormal frequency of lymphocyte subsets in the blood, by increased prostaglandin production, and deficient lymphokine production.

Imexon and biological response modifiers in murine models of AIDS

The Rauscher murine leukemia retrovirus system provides an in vivo model of the human acquired immune deficiency syndrome for testing the ability of antiviral agents and biological response modifiers (BRM) to suppress viremia and retroviral disease. In the present report we examined three agents in the Rauscher retrovirus model: imexon, Ampligen and poly[I,C]-LC. Imexon reduced splenomegaly, viremia, and serum reverse transcriptase levels even when treatment was not initiated until 7 days after virus infection. Imexon also significantly prolonged the survival of infected mice. Thus it proved to be an effective antiviral agent in this system, although imexon did not completely eliminate retroviral infection in treated mice. Poly[I,C]-LC and Ampligen had immunomodulatory effects. Both of these BRM augmented the cytolytic activity of splenic natural killer (NK) cells in infected animals when treatment was initiated 24 h after infection. Poly[I,C]-LC had antiretroviral activity when administered on this schedule. In order to examine the role of NK cell augmentation in the antiviral activity of poly[I,C]-LC, we attempted to deplete NK activity by treatment with rabbit antibody to asialo GM1, a ganglioside on the surface of murine NK cells. Combined treatment of infected mice with poly[I,C]-LC and anti-asialo GM1 decreased the antiviral activity of poly[I,C]-LC. This finding suggests that NK cells may be involved in the antiviral effect of this BRM.

Immunological dysregulation of lymph nodes in AIDS patients

Changes in immune competent tissues of the HIV-1-infected person reflect to a certain extent the kind and intensity of immunological dysregulations. The diagnostic approach, however, must include immunophenotyping of cells, immunovirological studies of virus distribution in diseased tissues, and functional tests in addition to classical morphology. The latter technique alone just serves as a crude screening method since structural lesions in lymphoid tissues do not permit discrimination from other HIV-independent immune deficiency and autoimmune disorders. Although the overall appearance of lymph nodes in HIV infection and in chronic autoimmune disorders, such as collagen vascular diseases (e.g., rheumatoid arthritis and systemic lupus erythematosus), is similar, immunophenotyping shows a progressive loss of CD4 cells in HIV infection yet a quantitative increase in this cell population in autoimmune disorders (Krueger 1985a). In addition, there are other persistent active infections by lymphotropic viruses (e.g., EBV or HHV-6) which can cause structural and cellular changes in lymphoid tissues closely resembling HIV-induced lesions (Krueger et al. 1988b; Krueger 1985b). The pathological diagnosis therefore nedds to be supplemented by serological studies and--in selected cases--by in situ hybridization for the demonstration of viral genome. Southern blotting for viral DNA can only detect high numbers of viral genome copies in tissue extracts, not in which cell population the virus resides (e.g., malignant cells vs associated "normal" cells), while the polymerase chain amplification reaction, the most sensitive of all (Buchbinder et al. 1988), cannot yet differentiate between latent and (disease-related) active infection. Taking into consideration the above-described precautions in the evaluation of lymphatic lesions, there are a number of characteristic changes which reflect well the sequelae of HIV infection itself and of the ensuing immune dysregulation. Progressive loss of CD4 cells in the paracortex of lymph nodes and in the peripheral blood leads to inversion of the CD4/CD8 ratio. Loss of demonstrable CD4 cells is probably the consequence not only of cell lysis by HIV-1 infection (note: discrepancy between HIV-1 genome positive cell numbers and depletion of CD4 cells) but also of decreased CD4 marker synthesis in infected cells (Stevenson et al. 1987). In this context it is interesting that Fouchard et al. (1986) were able to show HIV expression in CD8 cells and theorized that these developed from infected CD4 cells which subsequently lost the CD4 epitope and expressed CD8.(ABSTRACT TRUNCATED AT 400 WORDS)

Production of tumor necrosis factor-alpha and interleukin-1 by alveolar macrophages from HIV-1-infected persons

Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) are potent immunomodulatory cytokines which are produced principally by cells of the macrophage-monocyte lineage. We conducted an investigation to assess the secretion of these cytokines by bronchoalveolar macrophages from patients with progressive stages of human immunodeficiency virus (HIV-1) infection. The mean level of TNF-alpha produced by macrophages from 9 patients with AIDS was significantly reduced compared with the responses of macrophages from 6 healthy HIV-1-seronegative persons, 6 patients with either asymptomatic HIV-1 infection or persistent generalized lymphadenopathy, and 6 patients with AIDS-related complex (ARC). The four study groups did not differ in their mean IL-1 beta responses. However, within the HIV-1-infected patient population, macrophages from 4 patients, 3 of whom had AIDS and 1 with ARC, failed to secrete detectable levels of IL-1 beta. All 4 patients were also nonresponsive in assays for TNF-alpha. These data establish that advanced HIV-1 infection may result in a pronounced dysfunction in the cytokine responses of alveolar macrophages.

Possible beneficial effects of neutralizing antibodies and antibody-dependent, cell-mediated cytotoxicity in human immunodeficiency virus infection

We studied the relationship between early human immunodeficiency virus type 1 (HIV-1) specific immune responses and pathogenesis of infection in participants enrolled in the multicenter AIDS cohort study (MACS). Sera collected at 6-month intervals for 2 years (visit 1-5) from 39 persons who seroconverted by enzyme-linked immunosorbent assay (ELISA) 6 months (visit 2) after enrollment were examined for isotype-specific Western blot reactivity, neutralizing antibodies (NA) against two divergent strains of HIV-1 (HIV-1IIIB and HIV-1RF), and for antibodies capable of participating in antibody-dependent, cell-mediated cytotoxicity (ADCC). These results were compared with changes in CD4+ cell number and episodes of lymphadenopathy. Twenty-five subjects had antibodies of at least one isotype reactive to at least one HIV-1 protein by Western blot at visit 1, before they became ELISA positive. NA reactive with HIV-1IIIB were detected before those reactive with HIV-1RF. NA were first observed in 11 sera at visit 2, in 22 sera at visit 3, and in 3 sera at visit 4; sera from three patients remained nonneutralizing through visit 5. In most cases, NA were detected after a decline in CD4+ cell numbers. The data are consistent with the interpretation that NA develop after about 16 to 18 months of declining CD4+ cell numbers, following which the rate of decline in CD4+ cell numbers slows. In contrast, HIV-1 envelope antigen-specific ADCC responses were first observed in 11 subjects at visit 1 when all 39 were NA and ELISA negative, in 12 subjects at visit 2, in 13 subjects at visit 3, and 1 subject at visit 4. Early ADCC responses were associated with high mean % CD4+ cell numbers and absence of lymphadenopathy throughout the 2-year observation period. Not all subjects who developed ADCC developed NA. In some subjects, ADCC and NA were detectable for the first time at the same visit, for others ADCC was detectable prior to NA, and for a few NA was detectable prior to ADCC. These findings suggest that ADCC and neutralization are mediated by different antibody populations, that they may partially inhibit the progress of HIV-1 infection, and that the late appearance of NA may relate to the failure of immunity to effect recovery from this infection.

Soluble Il-2 receptor serum levels--a marker for disease progression in patients with HIV-1 infection

Serum levels of soluble Il-2 receptors (sIl-2R) were measured in 88 patients with HIV infection, 28 patients from high-risk groups, and 28 normal donors. Elevated sIl-2R levels were found in 46% of asymptomatic seropositive patients, in 68% of patients with persistent generalized lymphadenopathy, and in 81% of patients with AIDS. Mean sIl-2R values increased with the progression of the disease and were most pronounced in patients with AIDS. A close correlation was found between sIl-2R levels and beta2-microglobulin (p less than 0.0001) and other prognostic parameters known to parallel clinical activity. In addition to being a valuable parameter in monitoring the course of the HIV infection, elevated sIl-2R levels may also be involved in the down-regulation of Il-2-dependent immune functions in AIDS.

Epidermal tumour necrosis factor alpha and interleukin 6-like activities in AIDS-related Kaposi's sarcoma. An immunohistological study

Biopsies from 6 patients with AIDS and Kaposi's sarcoma (KS) in the tumour stage, and 6 healthy controls, were immunohistologically examined for the presence of tissue-bound tumour necrosis factor alpha (TNF alpha) and interleukin 6 (IL-6) in the skin. TNF alpha was demonstrated using specific polyclonal antiserum to human recombinant TNF alpha. IL-6 was visualized indirectly using a polyclonal antiserum to partially purified human crude supernatants of activated human blood monocytes, followed by absorption with recombinant human IL-6. The cytokines were found identically located in epidermal cell membranes in stratum granulosum and spinosum of the epidermis from unaffected skin in both AIDS patients and in controls. Biopsies from KS elements showed markedly increased epidermal staining for both TNF delta and IL-6. It was not possible to detect TNF alpha or IL6 in the endothelial cells of the tumour. The observation of increased amounts of epidermal-bound TNF alpha and IL-6 in AIDS-related KS elements supplements previous studies indicating that the skin plays an active immunoinflammatory role in patients with AIDS.

Peripheral blood mononuclear cell abnormalities and their relationship to clinical course in homosexual men with HIV infection

Quantitative abnormalities of leukocyte subpopulations have been shown to correlate with clinical status in human immunodeficiency virus (HIV) infection. We have performed peripheral blood leukocyte phenotyping in 23 HIV-seropositive homosexual men, and correlated the results with clinical follow-up information. Individuals with CD4+ greater than 400/mm3 (Group 1) had less severe abnormalities in other mononuclear cell subpopulations than patients with CD4+ less than 400/mm3 (Group 2). Group 1 had decreased CD4+CDw29+ (B-cell inducer) cells, compared to HIV-seronegative homosexual controls, with normal CD4+CD45R+ (suppressor-inducer) cells, suggesting that CD4+ subpopulations are reduced at different rates. Group 2 had decreased counts for both CD4+CDw29+ and CD4+CD45R+ cells. Both groups had increased cytotoxic T cells (CD8+CD11b-), with decreased B cells and CD4+/CD8+ ratios, compared to HIV-seronegative homosexual controls. The Group 2 patients with subsequent clinical deterioration had particularly low CD4+ cells, CD4+CD45R+ cells, CD2+Ta1+ cells, and CD4+/CD8+ ratios and high CD8+CD11b- cells, compared to those with clinically stable illness. Our findings suggest that specific leukocyte subpopulations are altered differentially at various stages of HIV infection. However, the study involved only quantitative measurements of specific T- and B-cell subsets with no attempt to measure in vitro function. It is of course possible that normal numbers of cells in these subpopulations might be functionally deficient.

Malignancies in the acquired immunodeficiency syndrome

Aside from opportunistic infections, several neoplasms have been identified as part of the spectrum of acquired immunodeficiency syndrome (AIDS) as defined by the Centers for Disease Control. Kaposi's sarcoma (KS) was the first such neoplasm to be recognized within the spectrum of AIDS. Although the classic form of Kaposi's sarcoma had been well recognized prior to the epidemic of AIDS, it was quite distinct from the illness that was seen in its "epidemic" form in young homosexual males. In this setting, Kaposi's sarcoma is an aggressive disease, with extensive involvement of skin and mucous membranes, early dissemination to lymph nodes, impressive development of extreme lymphedema, even in the absence of bulky adenopathy, and rapid spread to visceral organs, including lungs and gastrointestinal tract, among others. Although rapid clinical progression and short median survival have been the rule, a spectrum of disease has been seen such that some patients have survived for many years with disease limited to the skin. Certain clinical and laboratory features, such as presence of unexplained fever, night sweats, weight loss ("B" symptoms), or significant T-4-lymphocytopenia, have been identified as indicators of poor prognosis. Various therapeutic interventions have been employed in epidemic KS, and although partial and complete remissions have occurred, no regimen yet reported has significantly improved the survival of treated patients. High-dose recombinant alpha interferon has produced response rates in approximately 30% of treated patients, although toxicity has been observed in approximately 30% as well. Likewise, vinblastine has produced similar response rates with no evidence of long-term efficacy or "cure." Aside from Kaposi's sarcoma, lymphoma primary to the central nervous system was recognized early in the AIDS epidemic as a criterion for inclusion within AIDS in patients less than sixty years of age. Several years after the initial reports of disease, it became apparent that specific types of systemic lymphoma were also quite extraordinary, and the definition of AIDS was amended in June 1985 to include high-grade B-cell lymphomas in individuals who had positive serology or virology for the human immunodeficiency virus (HIV). The AIDS-related lymphomas are characteristic, both pathologically and clinically. The vast majority of these cases have been high-grade B-lymphoid tumors of either immunoblastic or small-non-cleaved type (also known as "undifferentiated," Burkitt, or Burkitt-like).(ABSTRACT TRUNCATED AT 400 WORDS)

Diminished interferon gamma production may be the earliest indicator of infection with the human immunodeficiency virus

The degree of clinical severity in human immunodeficiency virus infected patients, ranging from asymptomatic seropositive subjects to acquired immune deficiency syndrome, as well as in individuals at risk was assessed in relation to: (1) T-cell subset balance and expression of markers of T-cell activation; (2) natural killer activity; and (3) interferon gamma production. A decrease in the CD4/CD8 (helper/suppressor) ratio and an increase in the percentage of CD8+ (suppressor/cytotoxic) cells coexpressing markers of activation (HLA-DR or CD25) were closely correlated with the clinical severity of the human immunodeficiency virus infection. Natural killer activity was significantly impaired in patients with acquired immune deficiency syndrome and acquired immune deficiency syndrome-related complex but normal in asymptomatic seropositive individuals and subjects at risk. Interferon gamma production, either in response to mitogens or the antigens from infectious agents commonly affecting human immunodeficiency virus-positive individuals, was decreased in patients with acquired immune deficiency syndrome or acquired immune deficiency syndrome-related complex, with lesser involvement in human immunodeficiency virus-seropositive subjects or individuals at risk. Four of the six persons in the last group seroconverted during the ten months subsequent to evaluation of their immune status. Since production of interferon gamma was diminished in these patients while other assays of immunity were normal, measurement of this lymphokine may be a useful determinant of infection with the human immunodeficiency virus.