Seropositivity for HIV and the development of AIDS or AIDS related condition: three year follow up of the San Francisco General Hospital cohort

A simulation model of AIDS in San Francisco: II. Simulations, therapy, and sensitivity analysis

The HIV and AIDS incidences each year for homosexual men in San Francisco are estimated from data. A computer simulation model for HIV transmission dynamics and progression to AIDS is used to reconstruct the HIV epidemic. Using some a priori parameter estimates, simulations are found that give good fits to the incidence data. In the stimulations the populations is divided into risk groups whose sexual activities are found to be strongly connected. There is saturation in the high-risk group, but changes in sexual behavior are more important in obtaining adequate fits. The simulation modeling yields useful parameter estimates, but the remaining uncertainty in parameter values implies that the simulation forecasts are also uncertain. Changes in HIV incidence lead to changes in AIDS incidence about 6-10 years later. Simulation models with and without zidovudine treatment both fit the incidence data; thus the effects of therapy on AIDS incidence are unclear. The fits of the simulation model are most sensitive to the yearly migration rate, the number of stages in the progression to AIDS, and the average number of new sexual partners per month; thus better estimates of these parameters would be desirable.

Quantitation of HIV: correlation with clinical, virological, and immunological status

A quantitative assay has been used to measure titres of infectious HIV in peripheral blood of symptomatic and asymptomatic patients. Viral titres were assessed in conjunction with virological and immunological status of patients including measurement of p24 antigen, antibody responses to structural (gp41, p24) and regulatory gene products (NEF, REV, TAT, and VIF), determination of beta 2 microglobulin levels and enumeration of lymphocyte subsets. Titres of HIV were significantly higher among symptomatic than asymptomatic patients. Viral load was closely associated with the number of CD4+ cells, the proportion of these cells harbouring HIV increasing with disease progression. Higher titres of infectious HIV among symptomatic patients was also associated with p24 antigenaemia and decreased antibody responses to NEF.

Management of the oral lesions of HIV infection

AIDS and other expressions of HIV infection continue to present ever-increasing challenges to the health professions, including dentistry. Patients with oral manifestations of HIV disease present or are referred to dental practitioners for the diagnosis and treatment of their oral lesions. This review briefly summarizes the management approaches currently adopted at the Oral AIDS Center, University of California, San Francisco.

Attitudes of paediatricians to HIV and hepatitis B virus infection

There is a recent upsurge of interest among health care professionals regarding the risk of accidental occupational exposure to HIV virus. We evaluated knowledge of virus carriage prevalence, needlestick injuries, venepuncture practices, and glove use among paediatricians in Wales and South West Regional Health Authorities. We also attempted to evaluate hepatitis B immunisation uptake in this group. Paediatricians have traditionally been considered a low risk group in the context of accidental occupational exposure to these viruses. We targeted a four point questionnaire at 221 paediatricians. Results suggested that despite recent increasing concern about these viruses, that is reflected in the amount of medical literature recently published, and the issuing of Department of Health guidelines on venepuncture, knowledge of prevalence of HIV and hepatitis B carriage rates, and hence assessment of risk magnitude, was surprisingly poor. Safe venepuncture practices were not widely used. In the 12 months before receiving the questionnaire 55% had suffered a needlestick injury with only 10% reporting the fact. Hepatitis B immunisation uptake was highest in the junior grades (but this does not necessarily mean those at greatest risk). There were many inconsistencies between the clinicians' perceptions of risk and their practices. As the virus attains a firm hold in the heterosexual population paediatricians by virtue of the nature of venepuncture in children will almost certainly see their risk of acquiring HIV/hepatis B viruses secondary to accidental occupational exposure increase over the next decade. Without an improvement in current knowledge of carriage prevalence in high risk areas and alteration in venepuncture practices/hepatitis B immunisation uptake some will unfortunately, though avoidably, contract these bloodborne viral infections.

Measurement of beta 2-microglobulin in serum by a particle-enhanced nephelometric immunoassay

A particle-enhanced immunoassay of beta 2-microglobulin in serum is described. It is based on the agglutination of complexes formed between the serum beta 2-microglobulin and latex particles coated with F(ab')2 fragments of polyclonal anti-beta 2-microglobulin antibodies. The analytical range of the method is 0.50 to 16 mg/l; it can be extended by appropriate dilution to 0.12 to 80 mg/l with good precision (CV less than 5% over the whole range). The accuracy and the precision are confirmed by a good correlation with radioimmunoassay (n = 123, r = 0.993). No error due to antigen excess was observed, even up to 292 mg/l. The main advantages of the method are its simplicity, its low cost per test and its high sensitivity (final dilution of the sample at 1/1200) with no known interference. The calibration curve is stable for at least 2 weeks.

Serum beta 2-microglobulin levels in asymptomatic HIV-1-infected subjects during long-term zidovudine treatment

beta 2-microglobulin levels were determined in the serum of 18 initially asymptomatic HIV-1 p24 antigenaemic subjects who were treated with zidovudine (+/- acyclovir) and who were followed for 2 1/2 years. The median serum beta 2-microglobulin level at week 0 was 2.5 mg/l and decreased to 2.3 mg/l after 12 weeks of treatment (p = 0.001). A correlation was found between individual changes in serum beta 2-microglobulin levels and individual changes in serum p24 antigen levels during the first 48 weeks of treatment (p less than 0.05). Six out of 18 subjects progressed to AIDS after 60-126 weeks of treatment. In this group during a period of more than one year before disease progression median serum beta 2-microglobulin levels increased from 2.5 mg/l to 3.3 mg/l (p = 0.03) and median CD4+ cell counts decreased from 0.3 x 10(9)/l to 0.08 x 10(9)/l (p = 0.03), while in that period the pattern of serum p24 antigen levels was inconsistent. Although the variability in serum beta 2-microglobulin levels appeared to make this marker unsuitable for management decisions in individuals, a decline in beta 2-microglobulin levels was found to parallel a decline in p24 antigen levels during the early phase of zidovudine treatment. Moreover, after prolonged treatment, rising beta 2-microglobulin levels--in contrast to p24 antigen levels--were shown to have predictive value for disease progression.

Prevalence of antibodies to human herpesviruses and hepatitis B virus in patients at different stages of human immunodeficiency virus (HIV) infection

The results of antibody assays for viruses of the herpes group (HSV, EBV, VZV and CMV) and for hepatitis B virus (HBV) were retrospectively evaluated in 439 HIV-seropositive patients classified into different stages of HIV infection. The prevalence of specific IgG, IgM and IgA antibodies in these groups was compared with that of a control group of HIV-negative unselected hospital patients. Antibodies to herpes viruses and HBV were more prevalent amongst HIV-seropositives, especially LAS and AIDS patients than in controls. However, marked differences were found only with CMV-IgG and anti-HBc-IgG, both with a comparatively low prevalence in HIV-negative persons (64.5% and 23.2%). Significantly more seropositives were found among asymptomatic HIV carriers (83.3% and 50%) and still more in patients with full-blown AIDS (95.4% and 82.5%). The increased frequency of CMV and HBV antibodies, already seen in asymptomatic HIV patients reflects their higher risk for sexually transmitted infections. Moreover, IgA antibodies to CMV were detected in 25.4% of LAS and 37.3% of AIDS patients, respectively, but only in 7.6% of the controls. Elevated CMV-IgA titres were found exclusively in HIV-infected persons. The differences in the antibody patterns found in this cross-sectional study may reflect the progression of the HIV disease. However, prospective follow-up studies are required to assess the value of these markers as indicators of prognosis in HIV-infected subjects.

High titers of cytopathic virus in plasma of patients with symptomatic primary HIV-1 infection

BACKGROUND

Primary infection with the human immunodeficiency virus (HIV-1) frequently causes an acute, self-limited viral syndrome. To examine the relations among viral replication, the immune response of the host, and clinical illness during this initial phase of infection, we undertook a quantitative, molecular, and biologic analysis of infectious HIV-1 in the blood and plasma of three patients with symptomatic primary infection and of a sexual partner of one of them.

METHODS

During an eight-week period of primary infection, HIV-1 was cultured frequently in dilutions of plasma and peripheral-blood mononuclear cells (PBMC), and levels of HIV-1 antigen and antibody were determined sequentially by enzyme-linked immunosorbent assay and immunoblotting. Replication-competent HIV-1 proviruses were cloned and characterized biologically.

RESULTS

Six to 15 days after the onset of symptoms, high titers of infectious HIV-1 (from 10 to 10(3) tissue-culture-infective doses per milliliter of plasma) and viral p24 antigen were detected in the plasma of all three patients. These titers fell precipitously by day 27, and the decline coincided with an increase in the levels of antiviral antibodies and the resolution of symptoms. Sequential isolates of virus from plasma and PBMC obtained throughout the period of primary infection, as well as virus derived from two molecular proviral clones, were highly cytopathic for normal-donor PBMC and immortalized T cells, despite the marked reduction in the titers of virus in plasma.

CONCLUSIONS

Primary, symptomatic HIV-1 infection is associated with high titers of cytopathic, replication-competent viral strains, and during such infection potential infectivity is enhanced. Effective control of HIV-1 replication during primary infection implies the activation of clinically important mechanisms of immune defense that merit further examination in relation to the development of antiviral therapy and vaccines.

Detection of human immunodeficiency virus type 1 transcripts in peripheral blood lymphocytes by the polymerase chain reaction

A simplified application of the polymerase chain reaction (PCR) to the routine detection of human immunodeficiency virus type 1 (HIV-1) transcripts from peripheral lymphocytes of infected subjects is described. This technique is simpler than previously described assays and was shown to be highly sensitive after ethidium bromide staining of polyacrylamide gel electrophoresis of amplified material. The method can be used for the virologic evaluation of HIV-1-infected subjects, thus allowing early identification of seropositive patients with signs of active infection.

Human immunodeficiency virus infection in Northern Ireland 1980-1989

To 31st December 1989, 71 persons are known to have attended medical practitioners in Northern Ireland with a diagnosis of Human Immunodeficiency Virus (HIV) infection. Twenty-one of these persons have had the diagnosis of Acquired Immune Deficiency Syndrome (AIDS) and 11 have died. The distribution of reports in the "at risk" categories of homosexual/bisexual males, injecting drug users, heterosexual males and females was significantly different (p less than 0.001) from those reported in the United Kingdom as a whole. Of tests for HIV infection carried out in patients attending the genitourinary medicine department of the Royal Victoria Hospital between 1987-1989, 0.16% have been positive. The prognostic value of the T4 lymphocyte count at presentation for the subsequent development of AIDS was significant (p = 0.0011). The commonest AIDS indicator disease diagnosed was Pneumocystis carinii pneumonia which was seen in seven of the 21 patients (33%).

Epitopes of human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins recognized by antibodies in the sera of HIV-1-infected individuals

Sera from human immunodeficiency virus (HIV)-infected study subjects and controls were analyzed by enzyme-linked immunosorbent assay using 10 synthetic peptides to identify epitopes of HIV envelope glycoproteins (ENVgp) that were recognized by antibodies. Two epitopes of HIV ENVgp, ENVP466 (amino acids 466-481) and ENVP497 (amino acids 497-509), were recognized by antibodies in the sera of most HIV-infected individuals. The frequency of individuals with detectable serum antibodies to these two epitopes was not associated with the stage of HIV disease. Purified antibodies to ENV497 had only very weak neutralizing activity against infectious HIV. These data suggest that a particular dominant type of antibody response to HIV's ENVgp has minimal protective effects. These and other studies to identify and stimulate immune responses to selected epitopes of HIV antigens may be useful in the design of vaccines to prevent or treat HIV infections.

Potential of community-wide chemotherapy or immunotherapy to control the spread of HIV-1

Whether zidovudine (3'-azido-3'-deoxythymidine, AZT) should be offered to symptomless individuals infected with human immunodeficiency virus type-1 (HIV-1), in the hope of delaying or even preventing progression to AIDS, has been much debated. The discussion has focused on the efficacy of the drug in delaying progression to disease, the severity of its side-effects, and the likelihood of its prolonged and widespread use resulting in zidovudine-resistant strains of the virus. Little attention has been given to the degree to which treatment reduces the infectiousness of symptomless patients, and to the concomitant implications for the overall transmission rate of HIV-1 in the community. Here we use simple mathematical models to show that community treatment with antiviral drugs or immunotherapies that lengthen the incubation period of AIDS without significantly reducing the infectiousness of treated individuals, can increase the rate at which HIV-1 infection spreads (which is fairly obvious) and can even, under certain circumstances, increase the AIDS-related death rate in the community (which is less obvious).

The staging and monitoring by primary care providers of patients with human immunodeficiency virus infections

As HIV testing expands through the population, primary care physicians will become more involved in the testing process. They will also be caring for increasingly larger numbers of HIV infected people from the asymptomatic through those with AIDS, through hospice care, should that become appropriate. This article summarizes key areas of clinician support for the HIV infected, clinical and laboratory markers associated with rapid progression of the disease, and important problem areas in clinical management. It also presents a series of staging diagrams that have proven useful in assisting clinicians in educating patients about the natural history of the HIV infection, the rationale for staging, the rationale for the timing of AZT therapy and Pneumocystis prophylactic treatment, and the significance of various prognosticators in management as the disease progresses.

A University of California State-supported AIDS research award program--a unique state and university partnership in AIDS research

This article describes the State-supported University of California AIDS research award program and its major accomplishments. It shows how a partnership between a University and a State resulted in the formation of a successful, efficient, and cost-effective AIDS research award program. This program provides funds for rapid testing of investigator-initiated meritorious research ideas, new drugs, and treatment modalities. Funds were also utilized to establish three AIDS Clinical Research Centers, which evolved into regional consortia that coordinate trials of new drugs and other modalities. This program succeeded in involving investigators whose efforts have led to excellent medical care, advanced technologies, and new drugs for treating AIDS and AIDS-related diseases. The University remains committed to continuing support of all areas of AIDS research, emphasizing drug and vaccine development, pediatric AIDS, and AIDS prevention studies in groups at high risk for HIV infection.

Rheumatic symptoms and human immunodeficiency virus infection. The influence of clinical and laboratory variables in a longitudinal cohort study

The present study was designed to prospectively evaluate the frequency of rheumatic symptoms in a cohort of patients infected with the human immunodeficiency virus (HIV), to examine the relationship between such findings and a variety of clinical and epidemiologic variables, and to evaluate the impact of rheumatic symptoms on the natural history of the HIV infection. One hundred seventeen patients were evaluated over a mean of 24.6 months (range 0.5-85 months). Cumulatively, 1.7% had Reiter's syndrome, 1.7% had psoriatic arthritis, and 11.1% had various forms of oligoarticular/monarticular or polyarticular arthritis. The majority of the rheumatic symptoms developed during the longitudinal evaluation and predominantly affected patients with clinically advanced HIV infection. Patients with articular disease tended to have more progressive HIV infection and were more likely to experience disease progression to clinical acquired immunodeficiency syndrome or death. Our data suggest that the occurrence of rheumatic symptoms in the presence of HIV infection is not uncommon and tends to develop over time, in the setting of clinically advanced retroviral infection. Furthermore, the presence of rheumatic symptoms may be a sign of a poor prognosis for patients with HIV infection.

Serial CD4 lymphocyte counts and development of AIDS

Low CD4 lymphocyte counts are associated with increased risk of progression to AIDS in human immunodeficiency virus (HIV) infection. We investigated the extent to which the timing of progression to AIDS can be explained solely in terms of decline of the CD4 lymphocyte count in 111 haemophiliacs followed for up to 11 years since infection with HIV. A median of 10 CD4 lymphocyte counts were made per patient. By applying a simple linear model for the decline in CD4 lymphocyte counts over time, we estimated the date of development of AIDS in 96 patients who had at least 5 determinations. 84% (81 of 96) of patients were correctly classified as to development of AIDS before Jan 1, 1990 (p less than 0.0001), with this model. The results suggest that differences in the time at which patients with HIV will progress to AIDS can largely be explained by differences in rates of decline of CD4 lymphocyte counts.

Surrogate markers for survival in patients with AIDS and AIDS related complex treated with zidovudine

OBJECTIVE

To determine whether early effects of zidovudine treatment on CD4+ lymphocyte count and concentrations of beta 2 microglobulin, neopterin, or HIV p24 antigen or antibody are correlated with survival in patients with AIDS or AIDS related complex.

DESIGN

Retrospective study of changes in laboratory markers and survival.

SETTING

Multicentre trial at university hospital clinics.

SUBJECTS

90 Patients with AIDS or AIDS related complex.

INTERVENTION

Patients started zidovudine 200 mg orally every four hours. Fifty six of the patients died a median 17 months after starting zidovudine; the remaining 34 patients were followed up for a median 25.5 months.

MAIN OUTCOME MEASURES

Changes in CD4+ lymphocyte count and serum concentrations of p24 antigen and antibody, beta 2 microglobulin, and neopterin; survival of the patient.

RESULTS

The pretreatment characteristics that independently predicted poor survival were determined using a multivariate proportional hazards model: a diagnosis of AIDS (v AIDS related complex), age over 45 years, and the logarithm of serum neopterin concentration. When these baseline characteristics were controlled for the logarithm of CD4+ lymphocyte count at weeks 8-12 of treatment (p = 0.007) and an increase in serum beta 2 microglobulin concentration at weeks 8-12 (p = 0.05) also independently correlated with survival. In the 38 patients with a better pretreatment prognosis, 24 month survival estimated by the product-limit method was 88% for those with a good response on both surrogate markers during early treatment compared with only 50% for those with a poor response on either marker. In the 38 with a worse pretreatment prognosis, 24 month survival was estimated to be 49% for those with a good response on both surrogate markers compared with only 18% for those with a poor response on either.

CONCLUSION

These data suggest that CD4+ lymphocyte count at 8-12 weeks and, perhaps, change in serum beta 2 microglobulin concentration could be surrogate end points for clinical outcome in trials of antiretroviral drugs for patients with HIV disease.

Relation between humoral responses to HIV gag and env proteins at seroconversion and clinical outcome of HIV infection

OBJECTIVE

To study the contribution of the humoral response to HIV-I at seroconversion to disease outcome after 84 months.

DESIGN

A retrospective longitudinal study.

SETTING

Two haemophilia centres in the United Kingdom.

PATIENTS

88 Haemophiliac patients infected with HIV-I for whom sera were available from before seroconversion and in whom clinical follow up data were available.

RESULTS

Kaplan-Meier survival analysis showed a significant difference between a high titre (greater than 1600) p24 antibody response at seroconversion and prolonged time before the development of HIV related disease (p = 0.0008). In contrast, higher titres of antibody to gp120 at seroconversion (greater than 25,600) correlated with more rapid clinical deterioration (p = 0.025).

CONCLUSIONS

The first humoral response to HIV proteins at seroconversion is associated with clinical outcome; patients with an initial low titre antibody response to the gagp24 protein have a significantly faster rate of progression to CDC stage IV disease. Patients with a high titre p24 antibody response progress to AIDS more slowly, and these data provide an explanation why p24 antigenaemia is not universally detected in patients with AIDS. It is unclear whether the association between a strong initial p24 antibody response and slower progression of HIV disease is causal and if so whether it is due to viral or host factors.

Patterns of antibody reactivity to selected human immunodeficiency virus type 1 (HIV-1) gp160 epitopes infected individuals grouped according to CD4+ cell levels

We examined sera from 160 HIV-infected individuals for antibodies reactive to HIV-1 gp160 epitopes defined by seven synthetic peptides. Seropositive individuals were placed into three groups based upon levels of circulating CD4+ cells. These groups consisted of individuals with (1) more than 400 CD4+ cells, (2) 200-400 CD4+ cells, and (3) fewer than 200 CD4+ cells/mm3. The percentage of sera containing antibodies reactive with two immunodominant gp160 epitopes (a.a. 304-321 and 600-611) was unchanged between groups, regardless of CD4 cell numbers. The percentage of sera containing antibodies reactive with weakly immunogenic gp160 epitopes, such as those defined by peptides 425-448 and 846-860, declined in the groups as CD4 values decreased. Our results suggest that the patterns of antibody reactivity to gp160 epitopes change as CD4 levels decline. A narrowing of the humoral immune response to epitopes on the envelope of HIV-1 appears to occur with disease progression.

T4+ cell depletion as a major risk factor for AIDS-related complex and AIDS. Longitudinal study of 253 HIV-antibody positive heroin addicts from northern Italy

We enrolled 253 HIV-antibody positive heroin addicts without HIV-related disease (n = 81) or with persistent generalized lymphadenopathy (n = 172) in a prospective study to evaluate clinical progression to AIDS related complex (ARC) or AIDS and to identify factors of possible prognostic relevance. Follow-up lasted between 6 and 40 months (median 12 months). According to the non-parametric Cox's model the only significant (P less than 0.001) prognostic variable was T4+ cell count considered in three classes: greater than 800/microliters (no depletion), 400-800/microliters (moderate depletion) and less than 400/microliters (absolute depletion). Subjects with T4+ cell count of less than 400/microliters had a risk of developing ARC or AIDS that was 6.46 and 1.98 higher than those with values of greater than 800/microliters or between 400 and 800/microliters respectively. The estimated probability of progression to ARC or AIDS was 0.029, 0.056 and 0.172 at one year in subjects with T4+ cell count of greater than 800/microliters 400-800/microliters and less than 400/microliters, respectively, and 0.296, 0.501, and 0.896 at two years.

Clinical signs and laboratory markers in predicting progression to AIDS in HIV-1 infected patients

In a prospective longitudinal study 89 men with HIV-1 infection were observed for a mean time of 51 months with regard to clinical signs and laboratory findings predictive of progression to AIDS/opportunistic infection (OI). In a bivariate regression analysis the clinical signs showing a significant relation to AIDS development were: dermatitis of the face, yellow toe nail changes, hairly leukoplakia and oral candidiasis. The laboratory findings significantly associated with progression to AIDS were: decrease of the relative and absolute number of CD4 lymphocytes, decrease of the CD4/CD8 ratio, HIV p24 antigenaemia, lack of anti-HIV p24, elevated erythrocyte sedimentation rate, anaemia and elevated serum-beta-2-microglobulin. The relative number (%) of CD4 cells was found superior to the absolute number and the CD4/CD8 ratio. In a multivariate regression analysis decrease of CD4 lymphocytes and lack of anti-HIV p24 were independently associated with subsequent AIDS/OI development.

Neopterin and beta 2-microglobulin as prognostic indices in human immunodeficiency virus type 1 infection

The great majority of individuals with human immunodeficiency virus type 1 (HIV-1) infection presents with no signs or symptoms, or only lymphadenopathy. To initiate prophylactic measures in time it is necessary to establish risk criteria. CD4+ cell counts are significant predictors. Supplementary methods to improve the predictive information of CD4+ cell counts are still required. In addition, CD4+ cell counting is laborious, expensive, and restricted to specialized laboratories. Thus, there is also a place for more easily performed laboratory tests with similar predictive value as CD4+ cell counts. Neopterin and beta 2-microglobulin levels proved to be significant predictors of AIDS risk in HIV-1 seropositives. The predictive value of both parameters is equal to CD4+ cell counts and both markers are significant joint predictors in addition to CD4+ cell counts. Measurement of the parameters is done in serum (neopterin and beta 2-microglobulin) or urine (neopterin) specimens which reduces the risk of HIV-1 transmission compared to handling of whole-blood samples as it is required for cell counting. Although more studies are needed, especially in developing countries and in persons receiving zidovudine, it can be recommended to use neopterin and beta 2-microglobulin as additional marker to estimate AIDS risk in HIV-1 seropositive individuals. Moreover, both markers may be useful for this purpose without CD4+ cell counts if cell counting is not available.

Prognostic markers for AIDS

Human immunodeficiency virus (HIV) infection causes a number of clinical syndromes and many laboratory abnormalities, often heralding the development of the life-threatening opportunistic infections or malignancies that are known as the acquired immunodeficiency syndrome (AIDS). Drawing heavily on the results of prospective cohort studies, particularly those that my colleagues at the National Cancer Institute and I have conducted, this paper reviews the relationship of AIDS to clinical signs and symptoms, immunologic measures, and viral assays. The risk of AIDS in the next 3 years is at least 25 to 50% for HIV-infected subjects who have oral candidiasis, unexplained fever, unexplained weight loss, a CD4+ lymphocyte count below 200 cells/microliter, or combinations of these. Elevated serum levels of beta 2 microglobulin and neopterin also appear to be strong predictive markers of AIDS, but further work is needed in diverse HIV-infected populations, such as intravenous drug users and persons in pattern II countries, such as Haiti and central Africa. Elevated levels of interferon or HIV-p24 antigen in the serum are insensitive but highly specific AIDS markers that may have predictive value independent of CD4 lymphocyte levels. Several potentially valuable immunologic (immunoglobulin levels, tumor necrosis factor, soluble interleukin 2) and virologic (HIV viremia) assays remain to be thoroughly evaluated or technically simplified. Data from prospective cohort studies have provided clinical and laboratory markers of AIDS risk that have proved essential for therapeutic trials and other clinical decisions. As effective treatments for HIV infection and its complications begin to emerge, these marker data will also prove invaluable for mathematic modeling of the scope, course, and public health response to the epidemic.

Counseling patients seropositive for human immunodeficiency virus. An approach for medical practice

Persons at risk for infection with the human immunodeficiency virus are being encouraged to learn their serostatus. While such knowledge can help patients seek appropriate medical care, it can also be distressing. We describe an approach, based on crisis counseling, for physicians to use in working with patients infected with HIV. It can help physicians in assisting patients with emotional reactions to the diagnosis as well as in directing patients to manage practical issues of concern. Methods for discussing safer sex or injection practices are also presented.

Predicting progression to AIDS: combined usefulness of CD4 lymphocyte counts and p24 antigenemia

PURPOSE

To investigate the combined usefulness of CD4 lymphocyte counts and human immunodeficiency virus type 1 (HIV-1) p24 antigen in predicting progression to the acquired immunodeficiency syndrome (AIDS).

PATIENTS AND METHODS

CD4 lymphocyte counts and HIV-1 p24 antigen status were evaluated over a 4-year period in 518 HIV-1-seropositive men enrolled in the Multicenter AIDS Cohort Study in Chicago.

RESULTS

Twenty-six percent (134 of 518) of the HIV-1-seropositive cohort had detectable p24 antigen during the study period. Men with p24 antigenemia experienced a more rapid decline in CD4 lymphocyte counts than men who were persistently p24 antigen-negative (p less than 0.01). Mean CD4 lymphocyte counts at first detection of p24 antigen were 406 and 455 cells/microL for men with incident and prevalent antigenemia, respectively. Antigen was detected in 61% (63 of 103) of the men who progressed to AIDS and in only 17% (71 of 415) of the men who did not (p less than 0.0001). The 4-year estimated cumulative AIDS incidence was 86%, 63%, and 21% for men with entry CD4 counts less than 200, 200 to 399, and 400 or more cells/microL, respectively. Presence of p24 antigenemia was strongly associated with more rapid disease progression within each of these CD4 groupings (p less than 0.0001).

CONCLUSION

Our data indicate that p24 antigenemia can first be detected with moderate CD4 cell depletion, is associated with a more rapid decline in the CD4 lymphocyte population, and combined with CD4 lymphocyte counts is useful in identifying individuals at significantly greater risk of disease progression. Our findings provide important information for assessing HIV-1 disease prognosis over a 4-year period.

Course of HIV-I infection in a cohort of homosexual and bisexual men: an 11 year follow up study

OBJECTIVE--To characterise the natural history of sexually transmitted HIV-I infection in homosexual and bisexual men. DESIGN--Cohort study. SETTING--San Francisco municipal sexually transmitted disease clinic. PATIENTS--Cohort included 6705 homosexual and bisexual men originally recruited from 1978 to 1980 for studies of sexually transmitted hepatitis B. This analysis is of 489 cohort members who were either HIV-I seropositive on entry into the cohort (n = 312) or seroconverted during the study period and had less than or equal to 24 months between the dates of their last seronegative and first seropositive specimens (n = 177). A subset of 442 of these men was examined in 1988 or 1989 or had been reported to have developed AIDS. MAIN OUTCOME MEASURES--Development of clinical signs and symptoms of HIV-I infection, including AIDS, AIDS related complex, asymptomatic generalised lymphadenopathy, and no signs or symptoms of infection. MEASUREMENTS AND MAIN RESULTS--Of the 422 men examined in 1988 or 1989 or reported as having AIDS, 341 had been infected from 1977 to 1980; 49% (167) of these men had died of AIDS, 10% (34) were alive with AIDS, 19% (65) had AIDS related complex, 3% (10) had asymptomatic generalised lymphadenopathy, and 19% (34) had no clinical signs or symptoms of HIV-I infection. Cumulative risk of AIDS by duration of HIV-I infection was analysed for all 489 men by the Kaplan-Meier method. Of these 489 men, 226 (46%) had been diagnosed as having AIDS. We estimated that 13% of cohort members will have developed AIDS within five years of seroconversion, 51% within 10 years, and 54% within 11.1 years. CONCLUSION--Our analysis confirming the importance of duration of infection to clinical state and the high risk of AIDS after infection underscores the importance of continuing efforts both to prevent transmission of HIV-I and to develop further treatments to slow or stall the progression of HIV-I infection to AIDS.

Five year prospective study of HIV infection in the Edinburgh haemophiliac cohort

OBJECTIVE

To identify measures of immune state that reflect the course of HIV related disease in order to predict deterioration of symptoms and assess response to treatment.

DESIGN

Five year longitudinal clinical and laboratory study.

SETTING

Regional haemophilia centre, university virology laboratory, and Medical Research Council laboratory.

PATIENTS

32 Patients with haemophilia A exposed to a single batch of HIV contaminated factor VIII concentrate from the Scottish National Blood Transfusion Service in 1984 who were followed up regularly in Edinburgh (31) or abroad (one).

MAIN OUTCOME MEASURES

Counts of circulating T cell subsets (CD4 and CD8); plasma beta 2 microglobulin, neopterin, and IgA concentrations; and delayed type hypersensitivity to multiple skin test antigens.

RESULTS

18 Patients who seroconverted after exposure had received significantly more contaminated factor VIII than the 14 who did not (mean 43 (range 9-109) v 15 (3-30) phials, p less than 0.01). The two groups were not distinguishable by other criteria before exposure. The group that seroconverted subsequently showed a progressive fall in mean circulating CD4 lymphocytes and an increase in plasma beta 2 microglobulin and neopterin concentrations. From 1987 patients in this group also showed an increase in mean circulating CD8 lymphocytes and in plasma IgA concentration, neither of which was seen in patients who did not seroconvert. Patients with HIV antibody who developed Centers for Disease Control category IV symptoms within five years after infection showed more extreme changes in all measures, except CD8 lymphocyte count, than those whose symptoms remained in categories II and III. Skin test reactivity declined to barely detectable levels in all patients positive for HIV antibody.

CONCLUSIONS

Serial estimates of circulating CD4 lymphocytes and of plasma beta 2 microglobulin concentration are the most reliable measures of disease progression; of these, beta 2 microglobulin concentration seems to be the better predictor of impending serious symptoms. High IgA concentrations reflect rather than predict disease state. Individual variation in most measures is such that a wide range of measurements should be used in assessing the effects of trial treatment in HIV infected patients without symptoms.

A pilot study of low-dose zidovudine in human immunodeficiency virus infection

BACKGROUND

Zidovudine delays the progression of human immunodeficiency virus (HIV) infection but is associated with hematologic toxicity at high doses. Regimens are needed that preserve or enhance efficacy and reduce toxicity. Acyclovir has been reported to potentiate the effect of zidovudine on HIV in vitro.

METHODS

We conducted a Phase II open-label, dose-escalating trial to evaluate the clinical and antiviral effects of zidovudine at low (300 mg daily, 28 subjects), medium (600 mg, 24 subjects), and high (1500 mg, 15 subjects) doses, either with or without acyclovir (4.8 g) by random assignment. The subjects had the acquired immunodeficiency syndrome (AIDS)-related complex, but not AIDS. All of them had either HIV p24 antigenemia or plasma viremia and CD4-lymphocyte counts of 200 to 500 per cubic millimeter when they began treatment.

RESULTS

Performance scores and fatigue improved the most in the low- and medium-dose zidovudine groups (both P less than or equal to 0.025). Those assigned to low-dose zidovudine gained the most weight and had the greatest improvement in the mean CD4-lymphocyte count (from 321 per cubic millimeter at base line to 412 per cubic millimeter after 12 weeks, P = 0.01). The proportion of subjects in whom HIV antigenemia resolved, the decrease in the level of antigenemia, and the reduction in the plasma virus titers were similar at all three doses. Subjects assigned to receive the low or medium dose who subsequently crossed over to the 1500-mg dose (n = 19) did not have an increase in CD4-cell counts or a decline in levels of HIV antigen, but they did have dose-related toxicity. The addition of acyclovir to zidovudine was well tolerated, but it did not enhance any of zidovudine's antiretroviral effects.

CONCLUSIONS

In this pilot study a very low dose of zidovudine (300 mg) had clinical and virologic effects similar to those of higher daily doses (600 and 1500 mg). The minimal effective dose of zidovudine for the treatment of HIV infection has yet to be determined, and further studies of very low daily doses are warranted.

Beta 2-microglobulin and neopterin: predictive markers for human immunodeficiency virus type 1 infection in children?

The value of beta 2-microglobulin and neopterin concentrations in serum for early diagnosis of infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers was assessed. Concentrations of both markers were measured in serum samples from pediatric patients (Centers for Disease Control classifications P0, P1, and P2), as well as in age-matched normal subjects. Both beta 2-microglobulin and neopterin were significantly increased in HIV-1-infected symptomatic subjects (P2) compared to controls. Seventy-five percent of asymptomatic patients (P1) also had increased values. On the other hand, a significant overlap in concentrations of both markers in serum was found between controls and P0 patients. Thirty-eight percent of the P0 patients had values comparable to those of the P2 group. Persistently high concentrations of both markers in P0 patients may be indicative of HIV-1 infection.

Development of AIDS in a cohort of HIV-seropositive homosexual men in Australia

The Sydney AIDS Prospective Study is a cohort study of 1057 homosexual men enrolled between February 1984 and January 1985. By June 30, 1989, 111 (26.8%) of the 414 men who were seropositive for antibodies to human immunodeficiency virus (HIV) at enrollment had developed the acquired immunodeficiency syndrome (AIDS). On univariate analysis the following baseline factors were significantly associated with subsequent development of AIDS: splenomegaly; a lymphocyte count less than 1500 x 10(6)/L; a percentage of CD4+ cells less than 20% of the total lymphocyte count; an absolute number of CD4+ cells less than 200 x 10(6)/L; and a CD4+: CD8+ ratio less than 1.00. In a proportional hazards model the following factors retained significance: a lymphocyte count less than 1500 x 10(6)/L; an absolute number of CD4+ cells less than 200 x 10(6)/L; and a CD4+: CD8+ ratio less than 1.00. A CD4+ cell count less than 200 x 10(6)/L carried the greatest relative risk (3.99) for the development of AIDS. This study has confirmed that the appreciable rates of progression to AIDS demonstrated in overseas cohorts of HIV-infected persons also apply in the Australian context. A number of laboratory variables was found to be predictive for the subsequent development of AIDS. As we were not able to determine accurately whether subjects were receiving antiretroviral treatment or prophylaxis for opportunistic infections the observed rates in this study should be seen as minimum estimates. These findings have important implications for HIV-infected persons and for public health planning, and emphasise the need for regular clinical monitoring and T-cell subset enumeration in HIV-infected persons.

HIV infection and AIDS during adolescence

It is clear from the evidence that a growing number of adolescents are acquiring HIV infection and developing AIDS. The impact this epidemic will have on all teenagers is overwhelming. Given the high prevalence of risk-related sexual behaviors, many adolescents are likely to become HIV infected, thus requiring extensive medical and psychosocial services. Other adolescents will lose a parent, relative, or friend to AIDS, and these adolescents will similarly require special services and psychological counseling. Thus, there is an immediate need for the development of methods for (1) providing all adolescents with age-appropriate and culturally relevant interventions for prevention and risk reduction, (2) identifying high-risk adolescents and triaging them to different levels of care and risk reduction counseling, and (3) providing ongoing medical and psychosocial treatments. Accessing adolescents at risk for HIV infection will require networking between the health care system and youth-serving and community-based agencies, particularly agencies servicing high-risk adolescents. We must begin addressing these needs now, in order to prevent further infection and to provide appropriate care for those adolescents who are or will become infected with HIV.

Human immunodeficiency virus infection and the intestine

HIV is a retrovirus infecting CD4-positive cells causing profound immunosuppression, eventually clinically manifest as AIDS. The cells principally infected by HIV are T4 lymphocytes (helper) and macrophages. The eventual loss of helper cell function is the prime reason for immunodeficiency which renders the individual susceptible to opportunistic infections. HIV infection was first described in male homosexuals. However, the trend now is for seroprevalence to rise rapidly in intravenous drug abusers in the West. In addition, African AIDS is thought to be almost exclusively heterosexual in nature, a paradox which is not yet fully explained in comparison with the relatively low but increasing incidence in heterosexuals in the Western world. Virtually every organ system in the body can be affected clinically during the course of HIV infection. The gastrointestinal tract is a major target, and the physiological sequelae are an important cause of morbidity and mortality. The pathophysiology of intestinal infection is not yet fully understood, however two main mechanisms have been postulated. The first is reduced intestinal immunity resulting in chronic opportunistic infections, which themselves caused altered intestinal function. The second is that HIV itself affects the intestinal mucosa, causing malfunction. The mechanisms by which the latter occurs are controversial but may result from either direct infection of mucosal epithelial cells or macrophages within the mucosa. Reports have documented the presence of HIV genome in both epithelial argentachromaffin cells and macrophages. In addition, profound degeneration of intrinsic jejunal autonomic neurones has been demonstrated, but the functional significance of such denervation is as yet unknown. The clinical stage of HIV infection at which intestinal mucosal immunity fails is by definition when opportunistic infection occurs (that is, clinical progression to stage IV disease), namely AIDS, however a detailed knowledge of the mechanisms of intestinal immune failure are lacking.

Mortality and increasing drug use in Edinburgh: implications for HIV epidemic

Mortality among a group of known drug users shows small numbers of deaths from AIDS so far but increasing deaths from overdose, especially in young women. Steadily rising numbers of drug injectors are observed. The need for a distinctly different educational approach in areas of very high seroprevalence is discussed and the requirement for close co-operation between prescribing sources identified.

T activation marker evaluation in ARC patients treated with AZT. Comparison with CD4+ lymphocyte count in non-progressors and progressors towards AIDS

Reductions in the percentage and absolute number of CD4+ lymphocytes, as well as abnormally high levels of activated peripheral T lymphocytes (CD3+ HLA-DR+ phenotype) and an increased proportion of CD8+ cells coexpressing the CD57 surface antigen (involved in natural killer activity) have been reported in HIV infection and associated with disease progression. We prospectively measured these subsets of lymphocytes in 34 patients with advanced AIDS-related complex (ARC) treated with azidothymidine (AZT). Peripheral blood lymphocyte phenotyping was performed before treatment, then at weeks 12 and 24. A striking fall in the proportion of activated T lymphocytes from baseline was observed (P less than 0.001) at week 24. In contrast, the percentage of CD4+ cells showed a slight and transient rise at week 12 (P less than 0.05). No modification in levels of CD8+ or CD8+ CD57+ cells was detected during the study. Of the 34 patients, 11 developed AIDS, and 23 remained AIDS-free during 51 weeks of follow-up. Similar patterns of change in CD4+ and HLA-DR+ CD3+ lymphocytes were found in the AIDS progressors and nonprogressors. Likewise, HIV p24 antigenaemia showed parallel decreases in both groups of patients. Although changes in CD4+ cells, p24 antigenaemia and HLA-DR-reactive T lymphocytes were not predictive of clinical outcome, large differences existed between the two groups prior to the initiation of therapy. The short-term onset of AIDS was associated with lower CD4+ cell numbers, higher levels of serum p24 antigen and a greater proportion of activated T lymphocytes. Our results suggest that the possible interest of T lymphocyte activation markers, in conjunction with conventional phenotyping, should be investigated further.

Cells nonproductively infected with HIV-1 exhibit an aberrant pattern of viral RNA expression: a molecular model for latency

U1 and ACH-2 cells are subclones of HIV-1-infected monocyte/macrophage-like and T lymphocyte cell lines, respectively, which express the HIV-1 genome at very low levels. We have examined whether they might provide a model of HIV-1 latency. The patterns of HIV-1-specific RNA expressed in these cells consisted of singly and multiply spliced RNA species, with little or no full-length genomic RNA. Upon stimulation with agents that activate the HIV-1 long terminal repeat in these cells, a marked rise in the amount of small mRNAs, encoding the viral regulatory proteins, preceded the increase in the unspliced RNA. Thus, U1 and ACH-2 cells maintain HIV-1 in a state equivalent to the early phase of a lytic infection and, after stimulation, recapitulate the events of a single cycle infection of highly susceptible target cells.