Four-year prospective study of homosexual men: correlation of immunologic abnormalities, clinical status, and serology to human immunodeficiency virus

The prognostic significance in HIV infection of immune activation represented by cell surface antigen and plasma activation marker changes

One hundred and eighteen HIV-infected homosexual men without AIDS and 40 control seronegative homosexual men were assessed for 23 parameters reflecting immune activation to determine prognostic significance for occurrence of AIDS. Samples cryopreserved in 1987-1989 were analyzed, with AIDS occurrence determined by mid-1992. Cell surface antigens assessed on the major lymphocyte subsets were HLA-DR, CD38, CD71, and CD25. Soluble serum molecules assessed were tumor necrosis factor alpha, soluble TNFalpha receptor II, soluble IL-2 receptor alpha, neopterin, and beta2-microglobulin. Using a proportional hazards model, prognostic markers included decreased CD4 number and percentage; increased sIL-2R, neopterin, and beta2M; increased percentage HLA-DR+ total lymphocytes and CD4+ cells; increased CD38+ total lymphocytes and CD8+ cells; increased CD71+ total lymphocytes and CD4+ cells; and decreased CD25+ total lymphocytes and CD19+ cells. After adjustment for CD4 cell levels, sIL-2R, neopterin, beta2M, and CD25+ CD19 cells remained significant, indicating that additional information about AIDS risk was provided by these markers.

Relation of impaired lymphocyte proliferative function to other major human immunodeficiency virus type 1-induced immunological changes

Human immunodeficiency virus (HIV) type 1 (HIV-1) induces impairment of immune function reflected in reduced lymphocyte proliferative responses. Many other immune changes are induced by HIV-1, but their relationship to lymphocyte functional defects is not known. The present study was designed to correlate functional defects with other HIV disease parameters. Cryopreserved samples from 118 HIV-1-positive subjects and 40 seronegative individuals were examined. The main findings were that impaired proliferative responses to mitogens correlated with (i) decreased cell surface expression of the interleukin-2 receptor (CD25), (ii) increased expression of HLA-DR antigens on CD4 cells, (iii) reduced CD4 and increased CD8 cell numbers, and (iv) increased levels of serum immune complex dissociated p24 antigen. However, impaired function was not associated with increased serum neopterin, beta2-microglobulin, or soluble interleukin-2 receptor or with CD38 antigen expression on lymphocytes. In summary, proliferative functional impairment correlated with some, but not all, immunological changes associated with HIV-1 infection. Most of the phenotypic markers that correlated with altered function are cell surface molecules with significant roles in lymphocyte proliferation and were associated primarily with CD4 cells, compatible with the view that dysregulation of CD4 cells is responsible for impaired function.

Immunologic status in patients infected with HIV with oral candidiasis and hairy leukoplakia

Although numerous studies of oral manifestations associated with HIV have been reported, only a few refer to the correlation of these lesions with laboratory parameters. In this study we investigated the relationships between the two most common HIV-associated oral lesions, oral candidiasis and hairy leukoplakia, with the stage of the disease, circulating CD4+ cell counts, and the presence of anti-p24 antibodies in serum and stimulated whole saliva in 43 known HIV-1-infected persons. Although oral candidiasis and hairy leukoplakia were exclusively observed in subjects who were classified as Centers for Disease Control and Prevention group IV, only the prevalence of oral candidiasis is strongly associated with circulating CD4+ counts less than 200/mm3 (p < 0.02). The prevalence of oral candidiasis and hairy leukoplakia was significantly related to the absence of anti-p24 antibodies in serum (p < 0.01 and p < 0.01, respectively), but was only statistically significant for hairy leukoplakia in stimulated whole saliva (p < 0.02). The results suggest that oral candidiasis and hairy leukoplakia in correlation with immunologic status as indicated by low circulating CD4+ cell counts and the absence of anti-p24 antibodies in serum and the loss of secretory anti-p24 antibodies in subjects with hairy leukoplakia, may constitute prognostic markers for the progression of HIV-infection to AIDS. Our results also indicate that the absence of anti-p24 antibodies is not only influenced by the low levels of circulating CD4+ cells but probably by the presence of oral candidiasis or hairy leukoplakia as well.

Recovery of antitumor CD4+ T cell responsiveness, suppressed in the tumor-bearing state, by release from tumor burden

The present study investigates the recovery of antitumor CD4+ T cell responsiveness, suppressed in the tumor-bearing state, following release of tumor burden. Spleen cells from BALB/c mice bearing a syngeneic tumor (CSA1M) 1-3 weeks after the inoculation with CSA1M cells produced interleukin-2 (IL-2) and IL-4 upon in vitro cultures without addition of exogenous tumor antigens. This lymphokine production was achieved through collaboration between anti-CSA1M CD4+ T cells and antigen-presenting cells (APC) that has been pulsed with CSA1M tumor antigens in vivo in the tumor-bearing state. The lymphokine-producing capacity gradually decreased as the tumor-bearing period increased, and spleen cells from mice at late (8-10 week) tumor-bearing stages produced reduced levels of lymphokines. Because APC in these cells exhibited enhanced capacities to present tumor antigens, the reduced responsiveness was ascribed to the dysfunction of CD4+ T cells themselves. However, removal of a tumor after 8 weeks resulted in a remarkable recovery of the lymphokine-producing capacities of whole spleen cells. In contrast to the reduction in CSA1M-antigen-presenting activity of APC following tumor resection, CD4+ T cells exhibited a reciprocal increase in their responsiveness to CSA1M antigens. The recovery of antitumor responsiveness was also observed in the in vitro cultures free from tumor burden; when spleen cells from mice at late tumor-bearing stages were pre-incubated for 1-2 days and re-cultured in fresh medium, they produced potent amounts of IL-2 and IL-4. These results indicate that the immunodysfunction of antitumor CD4+ T cells induced in the tumor-bearing state is not irreversible, and release from tumor burden results in almost complete recovery of the potent antitumor responsiveness they previously expressed.

Using CD4 counts to evaluate the stages and epidemiology of HIV infection in South Carolina public clinic patients

OBJECTIVES

CD4 lymphocyte counts decrease with the duration of human immunodeficiency virus (HIV) infection. We used CD4 counts collected for clinical reasons to evaluate the stage of HIV infection and the epidemiology of recent HIV infections among attendees of South Carolina's public health clinics.

METHODS

We measured the CD4 T-lymphocyte counts of persons newly diagnosed with HIV infection April 1989 through June 1990 at South Carolina public health clinics who returned for follow-up.

RESULTS

Of 812 newly diagnosed HIV-infected health department patients, 420 (52%) had their CD4 lymphocyte counts measured. Of these 420, 51 (12%) had CD4 counts of < 200, the level below which prophylaxis for pneumocystis pneumonia prolongs survival, and 193 (46%) had CD4 counts of < 500, the level below which zidovudine may prolong disease-free survival. The highest CD4 counts (> or = 900), which are associated with more recent HIV infection, were more common in females.

CONCLUSIONS

In South Carolina, almost half of newly reported HIV-infected persons who agreed to CD4 testing at the health department might benefit from immediate drug therapy. Within this population, women may be an emerging risk group that requires specifically directed HIV prevention efforts.

Beta-2 microglobulin as a predictor of prognosis in HIV-infected men with haemophilia: a proposed strategy for use in clinical care

Whilst the prognostic value of serum beta-2 microglobulin (s-beta 2m) is well documented, the lack of a simple strategy for its use means that it is rarely ever measured in clinical practice. The prognosis associated with s-beta 2m at two different points in HIV infection, as defined by the CD4 count, was studied in a cohort of 111 men with haemophilia registered at the Royal Free Hospital School of Medicine, London. At CD4 counts of 0.5 and 0.2 x 10(9)/l, a raised s-beta 2m level was significantly associated with an increased risk of developing AIDS (P = 0.002 and 0.022 respectively, adjusted for the patient's age). Kaplan-Meier progression rates to AIDS by 4.5 years after a CD4 count of 0.5 x 10(9)/l were 57% (95% CI 32-82%) in those with s-beta 2m levels of 3 mg/l or more, but 20% (95% CI 4-36%) in those with s-beta 2m levels of less than 3 mg/l. By 3.5 years after a CD4 count of 0.2 x 10(9)/l, Kaplan-Meier progression rates to AIDS were 75% (95% CI 52-98%) in those with s-beta 2m levels of 3.8 mg/l or more, and 47% (95% CI 29-66%) in those with s-beta 2m levels of less than 3.8 mg/l. In the absence of acute viral infections, a raised s-beta 2m indicates those who will tend to progress to AIDS more rapidly than those with lower s-beta 2m levels and the same CD4 count. S-beta 2m levels in general are likely to be higher in haemophilia patients than in other, non-haemophilic risk groups. Whilst care should be taken, therefore, when applying our chosen cut-off values to non-haemophilic patients, our findings support the introduction of prophylaxis and antiviral therapies at a higher CD4 count in those with raised s-beta 2m levels relative to other patients in the same risk group whilst delaying treatment in those with lower CD4 counts, but relatively normal s-beta 2m levels.

Markers predicting progression of human immunodeficiency virus-related disease

Human immunodeficiency virus (HIV) interacts with the immune system throughout the course of infection. For most of the disease process, HIV activates the immune system, and the degree of activation can be assessed by measuring serum levels of molecules such as beta 2-microglobulin and neopterin, as well as other serum and cell surface phenotype markers. The levels of some of these markers correlate with clinical progression of HIV disease, and these markers may be useful as surrogate markers for development of clinical AIDS. Because the likelihood and timing of development of clinical AIDS following seroconversion, for any particular individual, are not readily predictable, the use of nonclinical disease markers has become critically important to patient management. Surrogate markers of HIV infection are, by definition, measurable traits that correlate with disease progression. An ideal marker should identify patients at highest risk of disease progression, provide information on how long an individual has been infected, help in staging HIV disease, predict development of opportunistic infections associated with AIDS, monitor the therapeutic efficacy of immunomodulating or antiviral treatments, and the easily quantifiable, reliable, clinically available, and affordable. This review examines the current state of knowledge and the role of surrogate markers in the natural history and treatment of HIV infection. The clinical usefulness of each marker is assessed with respect to the criteria outlined for the ideal surrogate marker for HIV disease progression.

Suppression of anti-tumor CD4+ T cell responsiveness in the tumor-bearing state and its recovery in in vitro culture free of tumor burden

We investigated whether the responsiveness of anti-tumor CD4+ T cells suppressed in the tumor-bearing state is reversed in conditions free of tumor burden. Spleen cells from BALB/c mice bearing a syngeneic tumor (CSA1M) 1-3 wk after inoculation with CSA1M cells produced interleukin-2 (IL-2) and IL-4 upon in vitro culture without addition of exogenous tumor antigens. This lymphokine production was achieved through collaboration between anti-CSA1M CD4+ T cells and antigen-presenting cells (APC) that had been pulsed with CSA1M tumor antigens in vivo in the tumor-bearing state. However, spleen cells from late (8-10 wk) tumor-bearing stages produced reduced levels of lymphokine production despite the presence of comparable proportions of CD4+ T cells. Because APC in these cell populations exhibited enhanced capacities to present tumor antigens, reduced responsiveness was ascribed to the dysfunction of CD4+ T cells themselves. When spleen cells from early tumor-bearing mice were preincubated for 1-2 days and recultured in fresh medium, the magnitude of lymphokine production by these cells was not changed. In contrast, the same protocol of preincubation and reculture for cells from late tumor-bearing mice resulted in the recovery of anti-tumor lymphokine-producing capacity. The recovered capacity was comparable to or slightly higher than that expressed by cells from early tumor-bearing stages. Since the CD4+ T cell content did not significantly differ before and after preincubation, enhanced lymphokine production was due to the recovered responsiveness of anti-tumor CD4+ helper T cells. The recovery of anti-tumor responsiveness was also induced in vivo by tumor removal at the late tumor-bearing stage: spleen cells from mice 2-4 wk after tumor resection efficiently produced IL-2 and IL-4. These results indicate that the immunodysfunction of anti-tumor CD4+ T cells induced in the tumor-bearing state is reversible because release from tumor burden either by preincubation in vitro or by tumor removal in vivo results in almost complete recovery of the potent anti-tumor responsiveness initially expressed.

Immune changes in HIV-1 infection: significant correlations and differences in serum markers and lymphoid phenotypic antigens

Human immunodeficiency virus type 1(HIV-1) induces extensive immune cell alterations which can be detected by changes both in serum levels of soluble immune activation products and in several lymphoid phenotypic markers. The current studies were conducted in 70 HIV-1 seropositive subjects to determine whether changes among four important serum immune activation markers (neopterin, beta-2 microglobulin, soluble CD8, and soluble IL-2 receptor) and seven lymphoid phenotypic markers (CD38, HLA-DR, CD57, CD11b, CD45RA, leu8, and CD71) reflect similar or disparate aspects of immune pathology. On the basis of correlation coefficient calculation, four groups of related markers (Fig. 1) were identified: Group A, sIL-2R was related to group B where serum neopterin, beta 2M, sCD8 levels, and lymphocyte CD38 antigen expression correlated closely. Loss of CD45RA or Leu 8 antigens in group C correlated with group B and D markers increase. HLA-D in group D was a more distantly related immune activation marker. Phenotypic markers CD57, CD11b, and CD71 did not correlate with the immune activation processes reflected by the serum and phenotypic marker groups A-D. Correlations between serum and certain lymphoid phenotypic markers were generally stronger later in HIV-1 infection when CD4 levels were less than 500/mm3. This study provides information for selecting markers for investigating immune changes in HIV-1 infection and immune-related diseases. Many serum and lymphoid phenotypic markers reflect related aspects of immune dysregulation. However, some markers can indicate different aspects of disease.

Using serial observations to identify predictors of progression to AIDS in the Toronto Sexual Contact Study

The Toronto Sexual Contact Study comprises a cohort of 249 male sexual contacts of men with HIV disease which has been followed every 3 months for almost 5 years. On enrollment 143 were seropositive and 16 seroconverted during the follow-up period. By 31 December 1989, 41 of the 159 seropositive cohort members had developed AIDS. Using Cox relative risk regression models, we investigated the association of a number of laboratory and clinical variables and progression to AIDS. Fixed covariate models examined laboratory variables from the enrollment visit of cohort members, with time calculated from this date. In models assessing time dependent covariates, time was calculated from the estimated date of HIV infection. In the univariate models of either fixed or time dependent covariates, many variables were significantly associated with risk of progression to AIDS (T4 cell count, T4/T8 ratio, blastogenic responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen, serum IgA, appearance of p24 antigen, and the development of oral hairy leukoplakia, thrush, or herpes zoster). Appearance of persistent generalized lymphadenopathy was not associated with increased risk of progression. In the multivariate model which evaluated fixed laboratory covariates, T4/T8 ratio, IgA level, and PHA response at enrollment were significantly associated with elevated risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Variation of secretory antibodies in parotid saliva to human immunodeficiency virus type 1 with HIV-1 disease stage

The secretory immune response to pathogens of the gut-associated lymphoid tissue is often independent of the systemic response. We investigated and compared the presence of antibodies to human immunodeficiency virus type 1 (HIV-1) antigens in parotid saliva and serum by Western blotting in 22 HIV-1-infected individuals. Antibodies to the HIV-1 envelope antigen gp160 were detected in saliva samples from 21 of 22 individuals and in serum from all individuals who were classified as CDC Group II, III, or IV. Antibody titers to gp160 were approximately 3000 times higher in serum than in saliva. Antibodies to viral core antigen p24 were detected in 6 of 7 Group II individuals in saliva and in 7 of 7 in serum. Antibodies to p24 were not found in the parotid saliva, but were detected in the sera of 3 of 3 Group III and 11 of 12 Group IV patients. The absence of secretory antibodies to HIV-1 core antigen p24 was correlated with CD4+ cell counts of less than 200/mm3. The results suggest that loss of secretory anti-p24 antibodies may be an early sign of progression to higher CDC clinical stages in HIV-1-infected individuals.

Prognostic significance of quantitative levels of HIV p24 binding capacity in HIV infection

Human immunodeficiency virus, type 1 (HIV-1), produces a chronic infection with a long latency before clinical disease. We followed 214 untreated subjects for 12-42 months to study the natural history of HIV infection: 110 were classified as asymptomatic, 11 as AIDS-related complex (ARC), 15 as AIDS with Kaposi's sarcoma (KS), 31 as AIDS with opportunistic infections (AIDS/OI), and 47 were HIV-seronegative controls. The quantitative capacity of serum to complex HIV p24 antigen, termed the p24 binding capacity (p24 BC), and quantitative levels of HIV p24 antigen in serum were determined at regular intervals. For people in all diagnostic groups, a p24 BC below 31 ng/ml was more closely associated with progression to AIDS/OI than was p24 antigen positivity; 94% of AIDS/OI, 86% of ARC, 56% of AIDS/KS, and 19% of asymptomatic subjects had p24 BC less than 31 ng/ml during the study period, while 67% of AIDS/OI, 27% of ARC, 61% of AIDS/KS, and 20% of asymptomatic subjects were p24 antigenemic. Prospective analysis of 47 asymptomatic seropositive men followed for 3 years, who showed actuarial progression rates to ARC at 4%, 13%, and 23% and to AIDS at 5%, 8%, and 8% at 1, 2, and 3 years, indicated that entry levels of p24 BC below 31 ng/ml were as strongly associated with progression to ARC/AIDS as was p24 antigenemia (p = 0.0003 vs. p = 0.008). The p24 binding capacity assay is a new and convenient methodology to measure immunocomplexing antibody to HIV p24 and is a powerful indicator of progressive HIV disease.

Serum factors in the progression of human immunodeficiency virus type 1 infection to AIDS

We studied the prevalence of four serum factors in individuals at different stages of human immunodeficiency virus-1 (HIV-1) infection. Soluble interleukin-2 receptors (sIL-2R) were elevated in all antibody-positive groups compared with high-risk, antibody-negative controls. Paraproteins, usually of the IgG-kappa isotype, were found in the sera of a significant number of HIV-1-infected individuals as were antibodies to lymphocytes (ALAs). Serum factors that inhibit proliferation of peripheral blood mononuclear cells from healthy donors appear late in the course of infection and were associated with increasing clinical severity. Measurement of these factors may prove to be useful in defining the stages of infection and in predicting the appearance or exacerbation of symptoms. They may also play a role in the development of the HIV-1-induced immune defects that lead to the expression of clinical acquired immunodeficiency syndrome.

Detection of three distinct patterns of T helper cell dysfunction in asymptomatic, human immunodeficiency virus-seropositive patients. Independence of CD4+ cell numbers and clinical staging

We have tested the T helper cell (TH) potential of asymptomatic, HIV seropositive (HIV+) patients, using an in vitro assay for IL-2 production. Peripheral blood leukocytes (PBL) from 74 HIV+ patients and 70 HIV- control donors were tested for TH function when stimulated with influenza A virus (FLU), tetanus toxoid (TET), HLA alloantigens (ALLO), or PHA. Of the HIV+ patients, four different response patterns were observed: (a) patients who responded to all four stimuli (16%); (b) patients who were selectively unresponsive to FLU and TET, but responded to ALLO and PHA (54%); (c) patients who were unresponsive to FLU, TET, or ALLO, but responsive to PHA (16%); and (d) patients who failed to respond to any of these stimuli (14%). Our results indicate a time-dependent progression from a stage responsive to all four stimuli to a stage unresponsive to any of the stimuli tested, progressing in the order outlined above. The earliest TH defect is the loss of responses to FLU and TET, indicating a selective defect in CD4+ MHC self-restricted TH function. The later loss of ALLO and PHA IL-2 responses suggests more severe TH dysfunction involving both CD4+ and CD8+ T cells. None of these patterns of TH unresponsiveness in asymptomatic HIV+ individuals were correlated with CD4+ cell numbers nor with Walter Reed staging criteria. This study indicates that the in vitro TH assay used can detect multiple stages of immune dysregulation early in the course of HIV infection and raises the possibility that staging of HIV+ patients should include in vitro TH functional analyses of the type described here.

Low AIDS attack rate among Dutch haemophiliacs compared to homosexual men: a correlate of HIV antigenaemia frequencies

A cohort of 180 haemophiliacs followed between 1983 and 1986 and a cohort of 961 homosexual men followed between 1984 and 1986 were compared for the prevalence and incidence of HIV-1 antibody (HIV-1-Ab) seropositivity, the incidence of AIDS-related complex (ARC) and AIDS and the prevalence and incidence of serological and immunological markers for HIV-related disease progression. Among the haemophiliacs 23 (12.8%) patients were HIV-1-Ab seropositive at entry and 20 (12.7%) of the remaining 157 seroconverted for HIV-1-Ab during follow-up. Of the homosexual men 238 (24.8%) were HIV-1-Ab seropositive at entry and 68 (9.4%) of the 723 at entry seronegatives seroconverted during follow-up. Clinical follow-up of the HIV-1-Ab seropositive and seroconverted men was 59 months in the haemophiliac cohort and 60 months in the homosexual cohort. Among the HIV-1-Ab seropositive and seroconverted haemophiliacs and homosexual men the cumulative ARC/AIDS incidence was 2 and 18%, respectively. Occurrence of HIV-1-antigenaemia was more frequent among seropositive and seroconverted homosexual men (28%) than among haemophiliacs (7%) (p = 0.001). The groups did not differ significantly for the absence or loss of anti-HIV core antibodies or the occurrence of low CD4+ cell numbers. These data indicate a slower progression of HIV-related disease in seropositive haemophiliacs compared to seropositive homosexual men.

Antibodies against the major core protein p24 of human immunodeficiency virus: relation to immunological, clinical and prognostic findings

In 79 homosexual men positive for antibody to human immunodeficiency virus (HIV), the titer and avidity of p24 antibody was determined by an indirect ELISA and the serum tested for the presence of HIV antigen. Results were examined for a possible correlation with clinical, immunological and prognostic findings. High titers and low avidity of p24 antibodies correlated significantly with a normal pokeweed mitogen response, early lymph node changes, and an asymptomatic and stable clinical condition. In HIV antigen negative patients, low titers and high avidity of p24 antibodies correlated significantly with a progressive clinical condition. The finding of primarily high avidity antibodies against p24 antigen in patients with more advanced immunodeficiency indicates that a decline of p24 antibodies during the clinical course of HIV infection may not be explained exclusively by an increased production of viral proteins.

Deterioration in immunologic status of human immunodeficiency virus (HIV)-infected homosexual men with lymphadenopathy: prognostic implications

Changes in immunologic parameters were followed in members of a cohort of human immunodeficiency virus (HIV)-positive homosexual or bisexual men with lymphadenopathy and were analyzed for differences between those who have and those who have not progressed to the acquired immunodeficiency syndrome (AIDS) (progressors, nonprogressors). T helpers and the Th/Ts ratio were lower in progressors than in nonprogressors both at entry into the study and at the latest visit. T suppressors were not different in the two groups at entry but were higher in nonprogressors at the latest visit. Evaluation of the patterns of change over time showed that T helpers and Th/Ts ratios tended to decrease over time in both nonprogressors and progressors, while T suppressors increased in nonprogressors and decreased in progressors. Although progressors had a greater deterioration in immunologic parameters over time, nonprogressors also had significant deterioration when compared with controls. Based on the respective percentages of men with abnormal or normal T helpers or Th/Ts ratio at entry who have already progressed to AIDS, we would conservatively estimate, considering their latest T helpers and Th/Ts ratio, that at least an additional 16 (32%) of our nonprogressors will develop AIDS in the next 5 years.

Markers for progression to acquired immune deficiency syndrome and zidovudine treatment of asymptomatic patients

Eighteen asymptomatic men with persistent human immunodeficiency virus type I (HIV-I) p24 antigenaemia were treated with zidovudine 250-500 mg (+/- acyclovir 800 mg) 6-hourly for 4-12 weeks, and subsequently with zidovudine 500 mg (+/- acyclovir 1600 mg) 12-hourly for 36 weeks. After 24 weeks six additional HIV antigenaemic subjects were entered and treated directly with zidovudine 500 mg 12-hourly. Over the treatment period serum HIV-I p24 (HIV-Ag) levels declined in all 24 subjects; significantly so in 17, and to below cut-off values in five. Mean serum HIV-Ag levels in different treatment groups declined in 68-78%. Initial increases in CD4+ cell counts were not sustained. Over 48 weeks serum HIV-Ag levels rose in three out of five non-treated men with persistent HIV antigenaemia, and they slightly declined in two; the mean serum HIV-Ag level in this group rose 67%. Regression of enlarged lymph nodes was seen in 19 out of 19 of the zidovudine-treated subjects. In the 24 zidovudine-treated subjects no disease progression occurred during follow-up, whereas two out of five non-treated men went on to develop CDC group IV A, and IV C-2 disease, respectively. Adverse reactions to the study drugs were infrequent and mild. Anaemia caused symptoms in two, but serious leucopenia or neutropenia was not observed. An initial positive effect on thrombocyte numbers was not sustained. These data demonstrate that in asymptomatic HIV-infected subjects zidovudine 500 mg 12-hourly is well tolerated and has a persistent inhibitory effect on viral replication.

Decline in CD4+ cell numbers reflects increase in HIV-1 replication

Changes in CD4+ cell numbers were studied in relation to the presence of HIV-1 antigen (HIV-1-Ag) in serum from homosexual men followed prospectively. During 30 months of follow-up the mean CD4+ cell number (x 10(9) per liter) was stable in 134 at entry HIV-1 antibody (HIV-1-Ab) seropositives, who remained HIV-1-Ag negative (from 0.59 to 0.62) and declined in 38 at entry HIV-1-Ab seropositives who were persistently HIV-1-Ag positive (from 0.43 to 0.34). In sera of 9 of 65 HIV-1-Ab seroconverters HIV-1-Ag was detected only once, 3 months before or concomitantly with antibody seroconversion. Another 11 men became persistently HIV-1-Ag positive with antibody seroconversion or 2-6 weeks thereafter. A decline in CD4+ cell numbers was seen between 6 months before and the moment of HIV-1-Ab seroconversion, independently of duration and level of antigen expression. This indicates initial HIV-1 replication in both HIV-1-Ag negatives and positives. Following antibody seroconversion, HIV-1-Ag negatives had higher CD4+ cell numbers than HIV-1-Ag positives. Similarly to those who were HIV antigenemic from entry of the study, the HIV-1-Ab seroconverters who concomitantly with seroconversion or shortly thereafter became HIV-1 antigenemic showed a steady and significant (p = 0.01) decline in CD4+ cell numbers. In those who remained HIV-1-Ag negative after antibody seroconversion, CD4+ cell numbers were stable during follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Serological response in patients with chronic asymptomatic human immunodeficiency virus infection

To examine a possible relationship between decreased immune function and serological parameters, such as human immunodeficiency virus (HIV) antigenaemia and the quality and quantity of whole virus antibodies and antibodies against the major core protein p24, we investigated 160 healthy HIV infected individuals (CDC classification II and III). According to the number of T-helper lymphocytes (CD4 cells) these were divided into two groups (CD4 cell counts above or below 500/microliter), which according to the lymphocyte transformation response to pokeweed mitogen (response above or below 20% of control value) were further subdivided into two groups. Both the presence of HIV antigen (p = 0.022) and the absence of p24 antibodies (p = 0.001) correlated to a decreased CD4 cell count. Lack of p24 antibodies was more frequent than was the presence of HIV antigen among persons with decreased CD4 cell count and decreased response to pokeweed mitogen, indicating that absence of p24 antibodies may be an earlier marker of immune dysfunction than the presence of HIV antigen. In persons with p24 antibodies present, a low such titer was associated with a decrease of both immune parameters. Presence of HIV antigen and absence of p24 antibodies thus seems to correlate with the severity of immune dysfunction in healthy HIV infected individuals.