The Walter Reed staging classification for HTLV-III/LAV infection

Nicotine is an Immunosuppressant: Implications for Women's Health and Disease

A plethora of evidence supports that nicotine, the primary alkaloid in tobacco products that is generally accepted for maintaining use, is immunoregulatory and may function as an immunosuppressant. Women have unique experiences with use of nicotine-containing products and also undergo significant reproductive transitions throughout their lifespan which may be impacted by nicotine use. Within the extant literature, there is conflicting evidence that nicotine may confer beneficial health effects in specific disease states (e.g., in ulcerative colitis). Use prevalence of nicotine-containing products is exceptionally high in individuals presenting with some comorbid disease states that impact immune system health and can be a risk factor for the development of diseases which disproportionately impact women; however, the mechanisms underlying these relationships are largely unclear. Further, little is known regarding the impacts of nicotine's immunosuppressive effects on women's health during the menopausal transition, which is arguably an inflammatory event characterized by a pro-inflammatory peri-menopause period. Given that post-menopausal women are at a higher risk than men for the development of neurodegenerative diseases such as Alzheimer's disease and are also more vulnerable to negative health effects associated with diseases such as HIV-1 infection, it is important to understand how use of nicotine-containing products may impact the immune milieu in women. In this review, we define instances in which nicotine use confers immunosuppressive, anti-inflammatory, or pro-inflammatory effects in the context of comorbid disease states, and focus on how nicotine impacts neuroimmune signaling to maintain use. We posit that regardless of potential health benefits, nicotine use cessation should be a priority in the clinical care of women. The synthesis of this review demonstrates the importance of systematically defining the relationships between volitional nicotine use, immune system function, and comorbid disease states in women to better understand how nicotine impacts women's health and disease.

A Historical Review of Military Medical Strategies for Fighting Infectious Diseases: From Battlefields to Global Health

The environmental conditions generated by war and characterized by poverty, undernutrition, stress, difficult access to safe water and food as well as lack of environmental and personal hygiene favor the spread of many infectious diseases. Epidemic typhus, plague, malaria, cholera, typhoid fever, hepatitis, tetanus, and smallpox have nearly constantly accompanied wars, frequently deeply conditioning the outcome of battles/wars more than weapons and military strategy. At the end of the nineteenth century, with the birth of bacteriology, military medical researchers in Germany, the United Kingdom, and France were active in discovering the etiological agents of some diseases and in developing preventive vaccines. Emil von Behring, Ronald Ross and Charles Laveran, who were or served as military physicians, won the first, the second, and the seventh Nobel Prize for Physiology or Medicine for discovering passive anti-diphtheria/tetanus immunotherapy and for identifying mosquito Anopheline as a malaria vector and plasmodium as its etiological agent, respectively. Meanwhile, Major Walter Reed in the United States of America discovered the mosquito vector of yellow fever, thus paving the way for its prevention by vector control. In this work, the military relevance of some vaccine-preventable and non-vaccine-preventable infectious diseases, as well as of biological weapons, and the military contributions to their control will be described. Currently, the civil-military medical collaboration is getting closer and becoming interdependent, from research and development for the prevention of infectious diseases to disasters and emergencies management, as recently demonstrated in Ebola and Zika outbreaks and the COVID-19 pandemic, even with the high biocontainment aeromedical evacuation, in a sort of global health diplomacy.

Walter Reed Army Institute of Research (WRAIR): Fifty Years of Achievements That Impact Science and Society

Thirty-four historical achievements since 1970 that emanated from scientific research at the Walter Army Institute of Research are identified and documented. Impact areas include vaccines, drug development, and clinical assays to prevent or treat infectious diseases; neuropsychiatric management of warrior performance and combat casualty; blood delivery management; and radiation protection.

The US Military HIV Natural History Study: Informing Military HIV Care and Policy for Over 30 Years

INTRODUCTION

In October 1985, 4 years after the initial descriptions of the acquired immunodeficiency syndrome (AIDS), the U.S. Department of Defense (DoD) began routine screening for human immunodeficiency virus (HIV) infection to prevent infected recruits from exposure to live virus vaccines, implemented routine active-duty force screening to ensure timely care and help protect the walking blood bank, and initiated the U.S. Military HIV Natural History Study (NHS) to develop epidemiologic, clinical, and basic science evidence to inform military HIV policy and establish a repository of data and specimens for future research. Here, we have reviewed accomplishments of the NHS over the past 30 years and sought to describe relevant trends among NHS subjects over this time, with emphasis on combination antiretroviral therapy (cART) use and non-AIDS comorbidities.

METHODS

Subjects who were prospectively enrolled in the NHS from 1986 through 2015 were included in this analysis. Time periods were classified by decade of study conduct, 1986-1995, 1996-2005, and 2006-2015, which also correlate approximately with pre-, early-, and late-combination ART (cART) eras. Analyses included descriptive statistics and comparisons among decades. We also evaluated mean community log10 HIV viral load (CVL) and CD4 counts for each year.

RESULTS

A total of 5,758 subjects were enrolled between 1986 and 2015, of whom 92% were male with a median age of 28 years, and 45% were African-American, 42% Caucasian, and 13% Hispanic/other. The proportion of African-Americans remained stable over the decades (45%, 47%, and 42%, respectively), while the proportion of Hispanic/other increased (10%, 13%, and 24%, respectively). The CD4 count at HIV diagnosis has remained high (median 496 cells/uL), while the occurrence of AIDS-defining conditions (excluding low CD4 count) has decreased by decade (36.7%, 5.4%, and 2.9%, respectively). Following the introduction of effective cART in 1996, CVL declined through 2000 as use increased and then plateaued until guidelines changed. After 2004, cART use again increased and CVL declined further until 2012-15 when the vast majority of subjects achieved viral suppression. Non-AIDS comorbidities have remained common, with approximately half of subjects experiencing one or more new diagnoses overall and nearly half of subjects diagnosed between 2006 and 2015, in spite of their relatively young age, shorter median follow-up, and wide use of cART.

CONCLUSIONS

The US Military HIV NHS has been critical to understanding the impact of HIV infection among active-duty service members and military beneficiaries, as well as producing insights that are broadly relevant. In addition, the rich repository of NHS data and specimens serves as a resource to investigators in the DoD, NIH, and academic community, markedly increasing scientific yield and identifying novel associations. Looking forward, the NHS remains relevant to understanding host factor correlates of virologic and immunologic control, biologic pathways of HIV pathogenesis, causes and consequences of residual inflammation in spite of effective cART, identifying predictors of and potential approaches to mitigation of excess non-AIDS comorbidities, and helping to understand the latent reservoir.

An exponential Galerkin method for solutions of HIV infection model of CD4+ T-cells

In this study, we consider a nonlinear first order model about the infection of CD4⁺ T-cells by HIV. In order to solve it numerically, we present a new method based on exponential polynomials reminiscent of the Galerkin method. Considering the approximate solutions in the form of exponential polynomials, we first substitute these approximate solutions in the original model. Some relations are thus obtained, which we express in terms of matrices. Taking inner product of a set of exponential functions with these matrix expressions then yields a nonlinear system of algebraic equations. The solution of these equations gives the approximate solutions of the model. Additionally, the technique of residual correction, which aims to reduce the error of the approximate solution by estimating this error, is discussed in some detail. The method and the residual correction technique are illustrated with an example. The results are also compared with numerous existing methods from the literature.

Accelerating HIV Infection with Cardiopulmonary Bypass—Case Reports

Five men patients and 1 woman patient who underwent either coronary artery bypass grafting (in 2) or valve replacement (in 3) or combined procedures (in 1) presented with severe HIV infection during the postoperative period. Four patients were NYHA Class III of IV with 3 patients in extremis requiring emergency procedures. All procedures were performed with cardiopulmonary bypass with mean time of 109 ± 48 minutes and aortic cross-clamp of 52 ± 49 minutes. Although the immediate postoperative courses seemed benign or uncomplicated, all presented with severe infections during the late postoperative period following their procedures (twenty-one to ninety days). The opportunistic infections were Pneumocystis carinii pneumonia (2), toxoplasmosis in the central nervous system and lung (1), cryptococcal meningitis (1), Staphylococcus aureus endocarditis (1), and viral encephalitis (1). Three died with two months of surgery.

These complicated postoperative infections have raised the question of the safety of cardiopulmonary bypass in HIV-infected patients. Rational recommendations regarding preoperative HIV antibody testing, operative indications, and postoperative surveillance are offered.

Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection

Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis.

HIV infection is closely associated with enhanced host susceptibility to various opportunistic infections (OIs), among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is an early and common manifestation. Even in the era of effective ART, mucosal candidiasis is still a clinically relevant presentation in HIV-infected patients. The underlying mechanisms are not well defined. CD4-mediated immunity is the major host defense mechanism against C. albicans. We here investigated a group of ART naïve, HIV-infected human subjects and examined longitudinally the impact of HIV on C. albicans-specific CD4 T-cell immunity as compared to CD4 T-cell immunity specific for CMV, another opportunistic pathogen that usually does not cause active disease in early HIV infection. We found that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo and were preferentially depleted in progressive HIV-infected individuals as compared to CMV-specific CD4 T cells. Of importance, we also found that in these HIV-infected subjects C. albicans-specific CD4 T cell response manifested a sequential dysfunction with earlier impairment of Th17, but not Th1, functions. Our study suggests an immunological basis that helps explain the earlier and more common onsets of mucosal candidiasis in progressive HIV-infected patients.

Continuous Antigenic Stimulation of DO11.10 TCR Transgenic Mice in the Presence or Absence of IL-1β: Possible Implications for Mechanisms of T Cell Depletion in HIV Disease

Untreated HIV disease is associated with chronic immune activation and CD4(+) T cell depletion. A variety of mechanisms have been invoked to account for CD4(+) T cell depletion in this setting, but the quantitative contributions of these proposed mechanisms over time remain unclear. We turned to the DO11.10 TCR transgenic mouse model, where OVA is recognized in the context of H-2(d), to explore the impact of chronic antigenic stimulation on CD4(+) T cell dynamics. To model dichotomous states of persistent Ag exposure in the presence or absence of proinflammatory stimulation, we administered OVA peptide to these mice on a continuous basis with or without the prototypic proinflammatory cytokine, IL-1β. In both cases, circulating Ag-specific CD4(+) T cells were depleted. However, in the absence of IL-1β, there was limited proliferation and effector/memory conversion of Ag-specific T cells, depletion of peripheral CD4(+) T cells in hematolymphoid organs, and systemic induction of regulatory Foxp3(+)CD4(+) T cells, as often observed in late-stage HIV disease. By contrast, when OVA peptide was administered in the presence of IL-1β, effector/memory phenotype T cells expanded and the typical symptoms of heightened immune activation were observed. Acknowledging the imperfect and incomplete relationship between Ag-stimulated DO11.10 TCR transgenic mice and HIV-infected humans, our data suggest that CD4(+) T cell depletion in the setting of HIV disease may reflect, at least in part, chronic Ag exposure in the absence of proinflammatory signals and/or appropriate APC functions.

A Brief Chronicle of CD4 as a Biomarker for HIV/AIDS: A Tribute to the Memory of John L. Fahey

Foundational cellular immunology research of the 1960s and 1970s, together with the advent of monoclonal antibodies and flow cytometry, provided the knowledge base and the technological capability that enabled the elucidation of the role of CD4 T cells in HIV infection. Research identifying the sources and magnitude of variation in CD4 measurements, standardized reagents and protocols, and the development of clinical flow cytometers all contributed to the feasibility of widespread CD4 testing. Cohort studies and clinical trials provided the context for establishing the utility of CD4 for prognosis in HIV-infected persons, initial assessment of in vivo antiretroviral drug activity, and as a surrogate marker for clinical outcome in antiretroviral therapeutic trials. Even with sensitive HIV viral load measurement, CD4 cell counting is still utilized in determining antiretroviral therapy eligibility and time to initiate therapy. New point of care technologies are helping both to lower the cost of CD4 testing and enable its use in HIV test and treat programs around the world.

A multi-stage compartmental model for HIV-infected individuals: I--waiting time approach

Traditionally, epidemic processes have focused on establishing systems of differential-difference equations governing the number of individuals at each stage of the epidemic. Except for simple situations such as when transition rates are linear, these equations are notoriously intractable mathematically. In this work, the process is described as a compartmental model. The model also allows for individuals to go directly from any prior compartment directly to a final stage corresponding to death. This allows for the possibility that individuals can die earlier due to some non-disease related cause. Then, the model is based on waiting times in each compartment. Survival probabilities of moving from a given compartment to another compartment are established. While our approach can be used for general epidemic processes, our framework is for the HIV/AIDS process. It is then possible to establish the impact of the HIV/AIDS epidemic process on, e.g., insurance premiums and payouts and health-care costs. The effect of changing model parameter values on these entities is investigated.

Tumour necrosis factor-alpha mediates blood-brain barrier damage in HIV-1 infection of the central nervous system

The pathogenesis of brain inflammation and damage by human immunodeficiency virus (HIV) infection is unclear. Because blood–brain barrier damage and impaired cerebral perfusion are common features of HIV-1 infection, we evaluated the role of tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in mediating disruption of the blood–brain barrier. Levels of TNF-α were more elevated in cerebrospinal fluid (CSF) than in serum of HIV-1 infected patients and were mainly detected in those patients who had neurologic involvement. Intrathecal TNF-α levels correlated with signs of blood–brain barrier damage, manifested by high CSF to serum albumin quotient, and with the degree of barrier impairment. In contrast, intrathecal IL-1β levels did not correlate with blood-brain barrier damage in HIV-1 infected patients. TNF-α seems to be related to active neural inflammation and to blood–brain barrier damage. The proinflammatory effects of TNF-α in the nervous system are dissociated from those of IL-1β.

Increasing rates of obesity among HIV-infected persons during the HIV epidemic

BACKGROUND

The prevalence and factors associated with overweight/obesity among human immunodeficiency virus (HIV)-infected persons are unknown.

METHODS

We evaluated prospective data from a U.S. Military HIV Natural History Study (1985-2004) consisting of early diagnosed patients. Statistics included multivariate linear regression and longitudinal linear mixed effects models.

RESULTS

Of 1682 patients, 2% were underweight, 37% were overweight, and 9% were obese at HIV diagnosis. Multivariate predictors of a higher body mass index (BMI) at diagnosis included more recent year of HIV diagnosis, older age, African American race, and earlier HIV stage (all p<0.05). The majority of patients (62%) gained weight during HIV infection. Multivariate factors associated with a greater increase in BMI during HIV infection included more recent year of diagnosis, lower BMI at diagnosis, higher CD4 count, lower HIV RNA level, lack of AIDS diagnosis, and longer HIV duration (all p<0.05). Nucleoside agents were associated with less weight gain; other drug classes had no significant impact on weight change in the HAART era.

CONCLUSIONS

HIV-infected patients are increasingly overweight/obese at diagnosis and during HIV infection. Weight gain appears to reflect improved health status and mirror trends in the general population. Weight management programs may be important components of HIV care.

Cutaneous malignancies among HIV-infected persons

BACKGROUND

As the life expectancy of persons infected with human immunodeficiency virus (HIV) increases, cancers have become an important cause of morbidity and mortality. Although cutaneous cancers are the most common malignant neoplasms in the general population, little data exist among HIV-positive persons, especially regarding the impact of HIV-specific factors.

METHODS

We evaluated the incidence rates and factors associated with the development of cutaneous malignancies among HIV-infected persons by examining data that were prospectively collected from a large HIV study that included 4490 participants (1986-2006). Poisson regression and Cox proportional hazards models were performed.

RESULTS

Six percent of HIV-infected persons (n = 254) developed a cutaneous malignancy during 33 760 person-years of follow-up (mean, 7.5 years). Since the advent of highly active antiretroviral therapy (HAART), the incidence rates of cutaneous non-AIDS-defining cancers (NADCs), in particular basal cell carcinoma, have exceeded the rates of cutaneous AIDS-defining cancers such as Kaposi sarcoma. Factors associated with the development of cutaneous NADCs in the multivariate models included increasing age (hazard ratio [HR], 2.1; 95% confidence interval [CI], 1.7-2.6) and race. Compared with the white/non-Hispanic race, African Americans (HR, 0.03; 95% CI, 0.01-0.14) and other races (HR, 0.14; 95% CI, 0.03-0.57) had a lower risk of cutaneous NADCs. There were no significant associations between cutaneous NADCs and time-updated CD4 lymphocyte counts, HIV RNA levels, or receipt of HAART.

CONCLUSIONS

At present, the most common cutaneous malignancies among HIV-infected persons are NADCs. Cutaneous NADCs do not appear to be significantly associated with immune function or HAART but rather are related to traditional factors such as aging and skin color.

Generality of the final size formula for an epidemic of a newly invading infectious disease

The well-known formula for the final size of an epidemic was published by Kermack and McKendrick in 1927. Their analysis was based on a simple susceptible-infected-recovered (SIR) model that assumes exponentially distributed infectious periods. More recent analyses have established that the standard final size formula is valid regardless of the distribution of infectious periods, but that it fails to be correct in the presence of certain kinds of heterogeneous mixing (e.g., if there is a core group, as for sexually transmitted diseases). We review previous work and establish more general conditions under which Kermack and McKendrick's formula is valid. We show that the final size formula is unchanged if there is a latent stage, any number of distinct infectious stages and/or a stage during which infectives are isolated (the durations of each stage can be drawn from any integrable distribution). We also consider the possibility that the transmission rates of infectious individuals are arbitrarily distributed--allowing, in particular, for the existence of super-spreaders--and prove that this potential complexity has no impact on the final size formula. Finally, we show that the final size formula is unchanged even for a general class of spatial contact structures. We conclude that whenever a new respiratory pathogen emerges, an estimate of the expected magnitude of the epidemic can be made as soon the basic reproduction number R0 can be approximated, and this estimate is likely to be improved only by more accurate estimates of R0, not by knowledge of any other epidemiological details.

Validity of a self-reported history of a positive tuberculin skin test. A prospective study of drug users

OBJECTIVE

To define the prevalence of and factors associated with having a negative purified protein derivative (PPD) among persons who self-report a prior positive PPD and to define the safety of repeat testing in such persons.

DESIGN

Observational cohort study.

SETTING

Methadone maintenance program with onsite primary care.

PATIENTS/PARTICIPANTS

Current or former drug users enrolled in methadone maintenance treatment.

INTERVENTIONS

Structured interview, tuberculin skin testing regardless of self-reported PPD status, and anergy testing.

MEASUREMENTS AND MAIN RESULTS

Nearly one third (31%) of participants who self-reported a prior positive PPD had a negative measured PPD, despite receipt of a "booster" PPD. A single participant (0.5%) blistered in response to the PPD without lasting ill effect. Participants with PPD results discordant from their history were more likely to be HIV-seropositive and nonreactive to the anergy panel. The discordance rate among HIV-infected participants was 43%, and was largely attributable to immune dysfunction. Among HIV-seronegative participants, the discordance rate was 27%. Recent crack-cocaine use was independently associated with discordance in the absence of HIV infection.

CONCLUSIONS

We confirmed that planting a PPD in patients who self-report a positive PPD history confers minimal risk. Substantial rates of discordance exist between self-reported history of a positive PPD and measured PPD status. Further research is needed to define the optimal management of PPD-negative patients who self-report a prior positive PPD and who have not received prior treatment for latent tuberculosis.

Total joint arthroplasty in human immunodeficiency virus-positive patients: an alarming rate of early failure

The results of 21 total joint arthroplasties (13 knees, 8 hips) in 15 patients were reviewed. There were 13 men and 2 women with an average age of 38 years (range, 28 to 69 years). The mean follow-up period was 10.2 years (range, 2 to 23 years). Six patients died within an average of 10.6 years (range, 3 to 18 years) of joint arthroplasty. All patients died of AIDS. Deep infection developed in 6 joints. Knee Society scores improved significantly, but 13 repeat surgeries were required. An alarmingly high rate of complications was found after total knee and total hip arthroplasty in these patients with human immunodeficiency virus (HIV). Physicians and surgeons should be made aware of this high rate of complications after joint arthroplasty in patients with HIV and include a frank discussion of this information with their patients who are contemplating total joint arthroplasty.

B cell activation in peripheral blood and lymph nodes during HIV infection

BACKGROUND

The spontaneous in-vitro antibody synthesis observed in unstimulated lymphocyte cultures from HIV-infected patients closely reflects the in-vivo activation of the B cell compartment; however, the mechanisms underlying this phenomenon are far from clear.

METHODS

We compared the ability of peripheral blood mononuclear cells (PBMC) and lymph-node cells (LNC) from 10 HIV-infected patients to produce in vitro HIV-specific and total Ig spontaneously, and we correlated these parameters with tumour necrosis factor alpha (TNF-alpha) expression by CD4 T cells, viral dissemination in the organism, and the extent of HIV spread into lymph-node germinal centres, measured by in-situ hybridization (ISH).

RESULTS

In-vitro spontaneous synthesis of both HIV-specific and total antibody was significantly higher in PBMC than in LNC; the two variables showed a good correlation in LNC, but not in PBMC. In both compartments, no correlation was found between B cell activation and the percentage of CD4 T cells expressing TNF-alpha, which was increased compared with seronegative donors. Furthermore, no correlation was found between in-vitro spontaneous antibody synthesis and the number of T cells containing proviral HIV in PBMC and LNC, or the plasma levels of HIV RNA. On the contrary, a good correlation was found between HIV-specific B cell activation and the extent of viral spread into lymph-node germinal centres, evaluated by ISH.

CONCLUSION

These data suggest that the adhesion of HIV virions to the follicular dendritic cell network in lymph-node germinal centres may primarily contribute to sustaining the steady B cell activation observed in HIV-infected patients.

Human immunodeficiency virus pathogenesis: insights from studies of lymphoid cells and tissues

Although plasma virus load is invaluable for monitoring human immunodeficiency virus (HIV) infection, key pathogenesis events and most viral replication take place in lymphoid tissues. Decreases in virus load associated with therapy occur in plasma and tissues, but persistent latent infection and ongoing viral replication are evident. Many unanswered questions remain regarding mechanisms of HIV-associated lymphocyte depletion, but partial CD4(+) cell reconstitution after therapy likely reflects retrafficking from inflamed tissues, increased thymic or peripheral production, and decreased destruction. Rapid establishment of latent infection and the follicular dendritic cell-associated viral pool within lymphoid tissues suggest that only early intervention could substantially alter the natural history of HIV. If therapy is started prior to seroconversion, some individuals retain potent HIV-specific cellular immune responsiveness that is suggestive of delayed progression. Although complete virus eradication appears out of reach at present, more attention is being directed toward the prospect of boosting HIV-specific immune responses to effect another type of "clinical cure": immune-mediated virus suppression in the absence of therapy.

Circulating soluble CD4 directly prevents host resistance and delayed-type hypersensitivity response to Cryptococcus neoformans in mice

In the present study, we examined the effect of soluble CD4 (sCD4) on host resistance and delayed-type hypersensitivity (DTH) response to Cryptococcus neoformans using a novel mutant mouse that exhibits a defect in the expression of membrane-bound CD4 but secretes high levels of sCD4 in the serum. In these mice, host resistance to this pathogen was impaired as indicated by an increased number of live pathogens in the lung. To elucidate the mechanism of immunodeficiency, three different sets of experiments were conducted. First, administration of anti-CD4 mAb restored the attenuated host defense. Second, in CD4 gene-disrupted (CD4KO) mice, host resistance was not attenuated compared to control mice. Third, implantation of sCD4 gene-transfected myeloma cells rendered the CD4KO mice susceptible to this infection, while similar treatment with mock-transfected cells did not show such an effect. These results indicated that immunodeficiency in the mutant mice was attributed to the circulating sCD4 rather than to the lack of CD4+ T cells. In addition, DTH response to C. neoformans evaluated by footpad swelling was reduced in the mutant mice compared to that in the control, and the reduced response was restored by the administration of anti-CD4 mAb. Finally, serum levels of IFN-gamma, IL-12 and IL-18 in the mutant mice were significantly reduced, while there was no difference in Th2 cytokines, such as IL-4 and IL-10. Considered collectively, our results demonstrated that sCD4 could directly prevent host resistance and DTH response to C. neoformans through interference with the production of Th1-type cytokines.

Prevalence and incidence of oral lesions--the changing scene

A range of oral mucosal and periodontal lesions is associated with HIV infection and HIV disease progression. These are often symptomatic and require treatment in themselves, and also have a diagnostic and prognostic role in the management of the underlying HIV disease. These lesions have been broadly divided into: (a) those strongly associated with HIV such as oral candidoses, oral hairy leukoplakia and Kaposi's sarcoma; (b) those less strongly associated such as swellings of the major salivary glands; and (c) those least commonly associated such as recurrent aphthous ulcers. Overall the prevalence and severity of these lesions inversely correlate with the level of immunosuppression. With the passage of time, there has been improved understanding of the disease pathogenesis resulting in the development of new drugs to combat this infection. Medication has changed from monotherapy to current triple combination therapy (Highly Active Anti-Retroviral Therapy). This review looks at the impact of changing therapy on the prevalence of the various oral lesions associated with HIV. It finds a decrease in the prevalence of the oral lesions in the era of combination therapy as compared to earlier periods. It also shows a change in the types of lesions which predominate with those previously placed amongst the strongly associated lesions no longer being predominant in the era of combination therapy where such treatment is available.

Screening for CMV retinitis using chromatic discrimination thresholds and achromatic contrast sensitivity

BACKGROUND

Many patients with cytomegalovirus retinitis (CMVR) are unaware of visual disturbance so screening is advocated for patients with HIV and low CD4 counts. Many tests of retinal function have been recommended but few are effective at detecting CMVR. We assess the potential of chromatic discrimination thresholds and achromatic contrast sensitivity as screening tests for patients with CMVR.

METHOD

11 HIV+ patients with CMVR, 16 age matched HIV+ patients, and 29 age matched controls were recruited. Visual acuity, chromatic discrimination thresholds, and achromatic contrast sensitivity were measured. Fundal examination was performed by slit lamp biomicroscopy for HIV+ patients. Those with CMVR were photographed and the CMVR graded from the photographs.

RESULTS

Loss of chromatic discrimination was found in patients with CMVR (tritan p<0.0005, red/green p<0.05). The same group had deterioration in achromatic contrast sensitivity at 2.2, 3.4, and 10 cpd (p<0.05). There was correlation between the zone of CMVR with chromatic gratings (tritan r=0.83, p<0.005). No statistically significant difference was found between the HIV+ patients and the controls for all tests (p>0.1).

CONCLUSIONS

HIV+ patients with CMVR have a loss of chromatic discrimination and achromatic contrast sensitivity and this may be used to screen HIV+ patients for CMVR.

Functions of oral candidiasis episodes that are highly prognostic for AIDS

Although oral candidiasis lesions are widely recognized as markers for AIDS, the relative prognostic significance of functions of these episodes has not been examined. We compare the associations with time to AIDS of one fixed and six time-dependent metrics of oral candidiasis lesions, including proximity of a lesion to seroconversion, any candidiasis history, and recency of a lesion. We show in Cox regression models that two metrics are clinically and statistically far more significant than the others, alone or in combination: any history of candidiasis since HIV seroconversion, and recency of a candidiasis episode. The latter metric indicates that the risk of an AIDS diagnosis is high during a candidiasis episode. The results hold for two cohorts of male seroconverters, 627 haemophiliacs and 196 men who have sex with men. Identification of highly prognostic functions of a patient's oral candidiasis history allows clinicians and researchers to focus on these aspects of the history and to omit extraneous information from data collection. Our method extends well beyond candidiasis and AIDS, and may shed light on associations of covariates with outcomes in a variety of settings.

Resting energy expenditure in asymptomatic HIV-infected females

The purpose of this study was to investigate whether resting energy expenditure (REE) is elevated in early, asymptomatic human immunodeficiency virus (HIV)-infected females and to study the contribution of a cytokine, tumor necrosis factor-alpha (TNF-alpha), to hypermetabolism. Cross-sectional comparison of REE in asymptomatic HIV+ females and a control group matched for age, body mass index (BMI), and fat-free mass (FFM). Twenty-six females aged 35 +/- 7 years (10 HIV+ [mean CD4+ T cell count 636/mm3] and 16 healthy controls) participated in this study. REE was measured by indirect calorimeter using a Deltatrac ventilated hood with a continuous rate of 40 L/min for 30 minutes after a 40-minute equilibrium period. All tests were performed after a 12-hour overnight fast. Twenty-four-hour urinary nitrogen was calculated to correct for respiratory quotient. Body composition was measured by bioelectrical impedance (BioAnalogics, Beaverton, OR). TNF-alpha was measured by ELISA (R & D Systems, Minneapolis, MN). Absolute REE was 17% higher (1755 kcal/kg +/- 410 versus 1497 kcal/kg +/- 197) in the HIV+ group compared with the control group (p < 0.05). REE remained significantly higher in the HIV+ group when REE was adjusted for body composition differences (p = 0.04). Results revealed a 23% higher level of TNF-alpha in the HIV+ subjects (p < 0.01); however, only a weak correlation existed between TNF-alpha and REE (r = .352). This study documented that hypermetabolism and elevated TNF-alpha exist in HIV+ females in the early stages of disease.

The prognostic value of the World Health Organisation staging system for HIV infection and disease in rural Uganda

OBJECTIVE

To assess whether the WHO staging classification for HIV provides prognostically valuable and applicable information in rural Uganda.

PATIENTS AND STUDY DESIGN

Data were obtained from a population-based cohort of 232 HIV-infected individuals.

METHODS

Clinical information was obtained using a detailed questionnaire and ascertained by physical examination. Participants were seen routinely every 3 months and when they were sick. A computer algorithm based on clinical history, examination and laboratory findings was used to stage HIV-positive participants at each routine visit. Kaplan-Meier survival estimates and the Cox proportional hazard model were used to assess the prognostic strength of the clinical and laboratory categories of the system.

RESULTS

An attendance rate of 81% and 799 person-years of follow-up were achieved. Survival probability estimates at 6 years from being seen in clinical stages 1, 2, 3 and 4 were 63, 46, 24 and 6% respectively. When staging was revised to incorporate lymphocyte categories, the survival probabilities were 73, 62, 39 and 6% respectively. Unexplained prolonged fever and severe bacterial infection had survival probabilities closer to stage 2 conditions, mucocutaneous herpes simplex virus infection for more than 1 month and crytosporidiosis with diarrhoea for more than 1 month closer to stage 3 and oral candidiasis closer to stage 4 conditions.

CONCLUSIONS

Even without the laboratory markers, the clinical category of the WHO staging system is useful for predicting survival in individuals with HIV disease. This is important for areas with limited access to laboratory markers. A simple rearrangement of a few clinical conditions could improve the prognostic significance of the WHO system.

Adenoidal and tonsillar lymphocyte subsets in AIDS children

Tonsils and adenoids are secondary lymphoid organs exposed to the environment. The most important classifications of AIDS include the lymphocyte subsets of peripheral blood. We have studied the lymphocyte subsets in peripheral blood and secondary lymphoid organs in a control group of children suffering adenotonsillar pathology and in five children with AIDS and the same adenotonsillar pathology. The antigen surface markers were determined by flow cytometry in lymphocytes isolated from peripheral blood, and from tonsils and adenoids after tonsillectomy and adenoidectomy, in the control group and in children diagnosed with AIDS. The most important findings in tonsils and adenoids were a decrease of the total T lymphocytes, helper T lymphocytes and CD4/CD8 ratio; an increase of cytotoxic T lymphocytes and B lymphocytes, as well as a 200% increase in monocytes of AIDS-affected children. These observations show the value of analyzing the lymphocyte subsets of the tonsils and adenoids of AIDS-affected children, and establishing an earlier relation to clinical symptoms.

Size and duration of zidovudine benefit in 1003 HIV-infected patients: U.S. Army, Navy, and Air Force natural history data. Military Medical Consortium for Applied Retroviral Research

OBJECTIVES

The study's objectives were to determine the size and duration of benefits of early versus delayed versus late treatment with zidovudine (ZDV) on disease progression and mortality in HIV-infected patients, and whether patients rapidly progressing before ZDV treatment had a different outcome from those not rapidly progressing before ZDV.

DESIGN

The design was an inception cohort of 1003 HIV-infected patients. One hundred and seventy-four of the 1003 patients were treated before CD4 counts fell to <400 x 10(9)/L, ("early treatment"); 183 of 1003 patients were treated after CD4 counts fell to <400 x 10(9)/L but before clinical disease developed ("delayed treatment"); and 646 of the 1003 patients had either been treated after clinical disease developed or had not been treated at all by the end of follow-up ("late treatment"). Outcomes were progression to clinical HIV disease and mortality.

RESULTS

The relative risk (RR) of progression for early versus delayed treatment was 0.58 (p < .03), and durability of ZDV benefits on progression was estimated at no more than 2.0 years; however, this estimate had wide confidence intervals. The RR of progression for delayed versus late treatment was 0.54 p < .0001, and durability of ZDV benefits was estimated at 1.74 years; this estimate had narrow confidence intervals. Survival was better for the early versus delayed treatment (RR = 0.55), but this difference was not statistically significant. In the subgroup of patients with more rapid CD4 decline prior to ZDV therapy, significant benefits on progression were observed for early versus delayed ZDV therapy (RR = 0.42, p = .02) and delayed versus late ZDV therapy (RR = 0.51; p = .0004). Duration of benefit was estimated to be 4.5 years (early versus delayed) and 1.7 years (delayed versus late). For patients with less rapid pre-ZDV decline in CD4 levels, a significant progression benefit was observed for delayed versus late therapy (RR = 0.50; p = .02). Duration of benefit in this subgroup was estimated to be 1.8 years. No significant benefit was found for early versus delayed treatment (RR = 1.12) in the less rapid pre-ZDV CD4 cell decline subgroup.

CONCLUSIONS

Early treatment compared with delayed treatment was associated with a sizable reduction in HIV progression, but the duration of benefits was estimated to last only about 2 years. Delayed treatment compared with late treatment with ZDV was associated with substantial reduction of progression, but this reduction was also clearly limited in duration. Benefits on progression and mortality for the early treatment group were heavily dependent on the pre-ZDV CD4 slope. In the subgroup of patients with the most rapid pre-ZDV CD4 cell declines, the duration of benefit was much longer, possibly as long as 4 years.

Cutting Edge: HIV-1 Infection Induces a Selective Reduction in STAT5 Protein Expression

HIV-1 infection is accompanied by qualitative and quantitative defects in CD4+ T lymphocytes. Loss of immune function in HIV patients is usually associated with a profound dysregulation of cytokine production. To investigate whether cytokine signaling defects occur during HIV infection, PHA blasts from healthy human donors were infected with two strains of HIV-1 and screened for the expression of STAT proteins used in cytokine signaling. A selective decrease in STAT5B was seen 8 days after infection with the BZ167 dual-tropic HIV isolate, but not with the Ba-L, M-tropic strain. Based on these findings, purified T cells from HIV-infected patients in different stages of disease were also tested for STAT expression; decreases in STAT5A, STAT5B, and STAT1α were observed in all patients. The reduction in STATs seen in vivo and in vitro after HIV infection may contribute to the loss of T cell function in HIV disease.

Predicting outcomes in HIV-infected veterans: I. Progression to AIDS

This article and the following article (Parts I and II) report the development of two clinical staging systems for HIV-infected individuals. The objective of the research reported here (Part I) was to construct a clinical staging system to predict progression to AIDS. We analyzed data from VA Cooperative Study Number 298, a multicenter, double-blind, randomized trial that compared immediate versus deferred zidovudine therapy in 338 HIV-infected individuals who did not have AIDS at enrollment. Baseline variables were tested in univariate Cox regression for their relationship to progression to AIDS, and those that appeared predictive were examined in multivariable analysis. Based on these analyses, we constructed a new clinical staging system based on CD4+ cell count, age, hemoglobin, oral hairy leukoplakia or oral thrush, and fever. The stages of the system were significant predictors of progression to AIDS (p = 0.0001, log-rank test). In conclusion, simple, valid, clinical staging systems for HIV-infected patients can be constructed using information that is readily available in clinical practice settings. Such systems provide better prognostic distinction than CD4+ cell count alone by taking into account the known prognostic effects of other variables.

TCR expression and clonality analysis in peripheral blood and lymph nodes of HIV-infected patients

We compared the T cell receptor (TCR) V beta gene family repertoire in peripheral blood mononuclear cells (PBMC) and lymph node (LN) cells from 7 human immunodeficiency virus (HIV)-infected patients and 3 seronegative healthy controls. Virtually all the V beta family specificities were represented in patient PBMC and LN cells, and mean values for each specificity were comparable to figures in seronegative controls. In 4 patients, however, some V beta gene segment transcripts were overrepresented in the LN compartment, compared to the peripheral blood counterpart. To ascertain whether this phenomenon was due to polyclonal or oligoclonal expansion of T cells bearing the relevant V beta gene product, we sequenced the entire CDR3 region of a panel of 238 PCR clones corresponding to the V beta transcripts expanded in LN; as control, the same regions were cloned and sequenced in patient's PBMC, and in PBMC and LN cells from seronegative individuals. This analysis disclosed preferential usage of J beta 2 genes in PBMC and LN cells from both seropositive patients and controls, regardless of the V beta gene segment considered, thus indicating that this skewness in the V beta-J beta repertoire could be a consistent feature of at least a part of the V beta repertoire in different lymphoid compartments, regardless of the pathologic conditions. In addition, in LN from HIV seropositive patients we found the presence of recurrent TCR rearrangements, accounting for 8-23% of the generated clones, in each of the 4 V beta specificities analyzed; recurrent sequences were not found in PBMC from patients nor in PBMC and LN cells from seronegative controls. These findings suggest that antigen-driven oligoclonal T cell expansions may occur in vivo in lymphoid organs of HIV seropositive patients.

Abnormal Expression of the B-Cell Homing Chemokine Receptor BLR1 During the Progression of Acquired Immunodeficiency Syndrome

The putative chemokine receptor BLR1 has been identified as the first G-protein–coupled receptor involved in B-cell migration and in microenvironmental homing to B-cell follicles and to germinal centers. In healthy individuals, expression of BLR1 is restricted to all mature recirculating B cells and to a subpopulation of T-helper memory cells. In the present study, we analyzed the distribution of BLR1 on defined lymphocyte subsets during the progression of acquired immunodeficiency syndrome. It is shown that the proportion of T-helper memory cells coexpressing BLR1 continuously decreases during the infection, whereas a high proportion of γ/δ T cells expressing BLR1 can be found in peripheral blood. The latter subpopulation is restricted to lymphoid tissues in healthy individuals. Most interestingly, in 75% of all human immunodeficiency virus (HIV)+ individuals, peripheral blood B cells were identified as not expressing BLR1 and phenotypically resembling germinal center cells of lymphoid tissue. Using BLR1 as a marker molecule, this study identifies peripheral blood lymphocytes in HIV+ individuals that are usually restricted to lymphoid tissue in healthy individuals. Because HIV infection is active in lymphoid tissue even at the clinically latent stage, aberrant expression of the B-cell homing chemokine receptor BLR1 might be an early indicator for the onset of destruction of lymphoid tissue.

Abnormal Expression of the B-Cell Homing Chemokine Receptor BLR1 During the Progression of Acquired Immunodeficiency Syndrome

The putative chemokine receptor BLR1 has been identified as the first G-protein–coupled receptor involved in B-cell migration and in microenvironmental homing to B-cell follicles and to germinal centers. In healthy individuals, expression of BLR1 is restricted to all mature recirculating B cells and to a subpopulation of T-helper memory cells. In the present study, we analyzed the distribution of BLR1 on defined lymphocyte subsets during the progression of acquired immunodeficiency syndrome. It is shown that the proportion of T-helper memory cells coexpressing BLR1 continuously decreases during the infection, whereas a high proportion of γ/δ T cells expressing BLR1 can be found in peripheral blood. The latter subpopulation is restricted to lymphoid tissues in healthy individuals. Most interestingly, in 75% of all human immunodeficiency virus (HIV)+ individuals, peripheral blood B cells were identified as not expressing BLR1 and phenotypically resembling germinal center cells of lymphoid tissue. Using BLR1 as a marker molecule, this study identifies peripheral blood lymphocytes in HIV+ individuals that are usually restricted to lymphoid tissue in healthy individuals. Because HIV infection is active in lymphoid tissue even at the clinically latent stage, aberrant expression of the B-cell homing chemokine receptor BLR1 might be an early indicator for the onset of destruction of lymphoid tissue.

Markers, cofactors and staging systems in the study of HIV disease progression: a review

This paper is aimed at providing a comprehensive review of markers, cofactors and staging systems used for HIV disease, focusing on some aspects that nowadays could even be considered historical, and advancing in current issues such as the prognostic value of viral load measurements, viral genotypic and phenotypic characterization, and new HIV disease treatment protocols. CD4+ cell values, combined with the new viral markers mentioned are promising as a parsimonious predictor set for defining both severity and progression. An adequate predictor of patient resource use for planning purposes still needs to be defined.

Surgical risk assessment and management in patients with HIV disease

Determining the perioperative risks associated with surgical procedures performed in patients with HIV disease is a difficult and complex task. Because HIV is a contagious, blood-borne pathogen, it threatens the health and well-being of both patient and health care provider. Despite poor early results, there is now convincing evidence that HIV infection is not a significant, independent risk factor for major surgical procedures. In practice, the authors evaluate the risk of surgery in patients with HIV infection using the same basic tools and guidelines applied to the uninfected, with the best predictors of surgical morbidity and mortality stemming from a careful and accurate assessment of the patient's cardiopulmonary, renal, endocrine, and nutritional reserve. Although HIV disease provides a unique constellation of diagnoses and challenges to the health care provider, the risk of major surgery in this population is not unlike that for other immunocompromised or malnourished patients. The authors believe that members of the surgical team have a professional, moral, and ethical responsibility to provide the highest possible quality of care for their patients, regardless of their HIV status. If after weighing the risks and benefits to the patient the surgeon believes the procedure will have a positive effect on the patient's life, the surgeon must offer surgical treatment. To do less does a disservice to the patient, the provider, and the profession as a whole.

Impaired induction of the apoptosis-protective protein Bcl-xL in activated PBMC from asymptomatic HIV-infected individuals

Progression to AIDS in asymptomatic HIV-infected individuals is characterized by a gradual but progressive loss of CD4+ T cells. While the mechanisms underlying this decline are currently unknown, recent evidence suggests that these cells are abnormally sensitive to apoptosis in response to activation signals. Recent work has implicated downregulation of Bcl-2 with the increased spontaneous apoptosis in lymphocytes from HIV-infected patients. We have evaluated the roles of the apoptosis-protective proteins Bcl-2 and Bcl-x in stimulated PBMC from asymptomatic HIV-infected and HIV-uninfected individuals. We found that Bcl-2 was constitutively expressed in PBMC from both HIV-infected and uninfected samples. However, Bcl-x induction was delayed and responses were decreased in stimulated HIV-infected samples. Additionally, single-cell intracellular staining of Bcl-x revealed a significant inverse correlation between PWM-induced Bcl-x expression and apoptosis (r = -0.695, P = 0.05). This was confirmed at the single-cell level in direct experiments when stimulated cells were sorted based on Bcl-x induction and then measured for apoptosis. Furthermore, low Bcl-x expression was not due to reduced lymphocyte activation following PWM stimulation. Our data indicate that the induction of Bcl-x is markedly impaired in asymptomatic HIV-infected patients and that stimuli which induce inadequate expression of Bcl-x are associated with increased levels of apoptosis in these cells.

Oral candidiasis in HIV infection: predictive value and comparison of findings in injecting drug users and homosexual men

The objectives of this study were to compare the relationship of oral candidiasis to HIV status, cohort and CD4+ lymphocyte values in injecting drug users and homosexual men and to examine its impact on prognosis. An oral examination was added to an ongoing longitudinal study of HIV infection. Data obtained at 6-month intervals included smoking, illicit drug use, medication use, symptoms and medical diagnoses, physical examination findings and laboratory data. In this study HIV+ subjects were much more likely to present with oral candidiasis than were HIV- subjects (OR = 6.3, P < 0.01). Injecting drug users, regardless of serostatus, were more likely than homosexual men to present with oral candidiasis (OR = 3.0, P = 0.001). In both cohorts oral candidiasis was associated with low CD4+ lymphocyte counts and percent ages, and Kaplan-Meier survival estimates showed that subjects with oral candidiasis had a poorer prognosis than those without candidiasis, even after controlling for CD4+ lymphocyte count.

Sentinels and signposts: the epidemiology and significance of the oral manifestations of HIV disease

A large number of studies attest to the frequency of oral disease in those with HIV infection. Most show that hairy leukoplakia and pseudomembranous candidiasis are the commonest lesions in those with HIV infection and AIDS, with higher prevalence and incidence rates correlating with falling CD4 counts and disease progression. HIV-infected individuals with oral candidiasis or hairy leukoplakia progress to AIDS more rapidly than matched controls without these lesions. Oral candidiasis and hairy leukoplakia increase with time since seroconversion. On the other hand, parotid enlargement in children appears to be associated with slower progression to AIDS. As a consequence of these and other observations, oral lesions are widely included in natural history studies, staging and classification schemes for HIV infection. In addition to their role in the diagnosis of HIV infection and as indicators of the progression of HIV disease, oral lesions are used as clinical correlates of CD4 counts and as criteria for entry into clinical trials.

Delayed-type hypersensitivity skin testing in human immunodeficiency virus-infected pediatric patients

OBJECTIVE

To evaluate whether pediatric patients infected with human immunodeficiency virus (HIV) can mount appropriate delayed-type hypersensitivity (DTH) skin responses to recall antigens and whether these responses can be correlated with clinical or immunologic parameters.

DESIGN

Prospective evaluation of DTH responses in HIV-infected children. Uninfected children born to HIV-infected mothers served as control subjects. Antigens used for yearly DTH testing included Candida albicans (1:100, 1:10); mumps virus; Trichophyton; purified protein derivative of tuberculin; and tetanus toxoid (1:100, 1:10). At the time of each DTH test, patients were staged according to two Centers for Disease Control and Prevention pediatric HIV classification systems, and T-cell subsets were obtained.

RESULTS

Twenty-seven HIV-infected patients with a median age at entry of 74.1 (range, 12 to 156) months were followed. Forty-four DTH skin tests in 21 symptom-free HIV-infected patients (PI) and 18 tests in 10 HIV-infected patients with symptoms (P2), as well as 43 DTH skin tests in 18 patients who had either mild or moderate clinical symptoms or immunosuppression and 19 tests in 13 patients with severe symptoms or immunosuppression, were evaluated. Sixteen DTH skin tests were performed in 14 uninfected patients. HIV-infected patients tended to have fewer DTH responses to antigens and of smaller size than did uninfected patients. When controlled for age, few differences in DTH responsiveness were seen between HIV-infected and uninfected patients. Anergy was associated with symptomatic disease, evidence of advanced clinical or immunologic disease, and low CD4+ percentages (p <0.05).

CONCLUSIONS

HIV-infected children are able to mount antigen-specific cell-mediated immune responses that are qualitatively similar to those of age-matched control subjects. Loss of DTH responsiveness correlates with both clinical and immunologic evidence of HIV disease progression.