Slim disease: a new disease in Uganda and its association with HTLV-III infection

Anabolic treatment with GH, IGF-I, or anabolic steroids in patients with HIV-associated wasting

Wasting, and particularly loss of metabolically active lean tissue, contributes to increased mortality, accelerated disease progression, and impairment of strength and functional status in patients with HIV infection. A variety of protein anabolic agents, including growth hormone, insulin-like growth factor-I, testosterone, nandrolone decanoate, oxandrolone, and oxymetholone, have been studied in patients with HIV-associated wasting. Overall, these studies have demonstrated that treatment with protein anabolic agents can increase lean body mass (LBM) and in some cases provide functional benefits and improvements in quality of life. Further research is needed to determine whether such treatment prolongs survival or reduces the overall health care burden of HIV infection. The advances in identification of successful treatments for HIV-associated wasting can provide a model for using these therapies in other catabolic states, including end-stage renal disease, cancer, chronic obstructive pulmonary disease, and cardiac cachexia.

Morbidity and nutritional impairment in relation to CD4 count in a Zambian population with high HIV prevalence

The HIV epidemic has greatly increased morbidity in many African cities and severe undernutrition is a prominent feature of the clinical presentation. However, there is little information about the relationship of morbidity or nutritional status to immune damage at a population level. We report a cross-sectional study of morbidity and nutritional status in relation to CD4 count in an impoverished urban community in Lusaka, Zambia, at enrollment into a longitudinal study. Over a 2 month period in 1999, 261 (52%) of 506 adults resident in one area were interviewed and examined. Of 186 adults who consented to testing, 33 (51%) of 65 who were HIV seropositive reported symptoms of disease compared to 39 (32%) of 121 who were HIV seronegative (OR 2.2, 95%CI 1.1-4.2; P=0.02). Peripheral blood CD4 counts in HIV seronegative individuals were broadly similar to norms in developed countries, but 8 (7%) had CD4 counts below 500 cells/microl. Morbidity in HIV seropositive adults was dominated by tuberculosis (n=11), other respiratory infections (5) or persistent diarrhoea (4), and affected individuals had a wide range of CD4 counts. Nutritional impairment was evident in HIV seropositive adults with clinical evidence of opportunistic infection (OI), not those with asymptomatic HIV infection. Unexpectedly, we also noted that systolic blood pressure was reduced progressively in HIV infection and in those with OI. In conclusion, HIV-related morbidity was dominated by a small number of treatable infectious diseases occurring over a wide range of CD4 count. Nutritional impairment was associated with OI.

The spread and effect of HIV-1 infection in sub-Saharan Africa

Africa is the continent most severely affected by the global HIV-1 epidemic, with east and southern Africa in general more severely affected than west and central Africa. Differences in the spread of the epidemic can be accounted for by a complex interplay of sexual behaviour and biological factors that affect the probability of HIV-1 transmission per sex act. Sexual behaviour patterns are determined by cultural and socioeconomic contexts. In sub-Saharan Africa, some traditions and socioeconomic developments have contributed to the extensive spread of HIV-1 infection, including the subordinate position of women, impoverishment and decline of social services, rapid urbanisation and modernisation, and wars and conflicts. Populations in many parts of Africa are becoming trapped in a vicious circle as the HIV-1 epidemic leads to high mortality rates in young and economically productive age groups, and thus leads to further impoverishment. Interventions to control HIV-1 should not only target individuals, but also aim to change those aspects of cultural and socioeconomic context that increase the vulnerability to HIV-1 of people and communities.

Albendazole chemotherapy for AIDS-related diarrhoea in Zambia--clinical, parasitological and mucosal responses

BACKGROUND

Albendazole reduces diarrhoea in African AIDS patients, but it is unclear if the clinical response to treatment reflects pathogen eradication and/or mucosal recovery.

METHODS

Adults with HIV-related persistent diarrhoea were treated with albendazole 800 mg twice daily for 14 days. Clearance of parasites was evaluated at 3 and 6 weeks by stool microscopy. At baseline and at 6 weeks duodenal biopsies were taken for electron microscopy (EM) and morphometry.

RESULTS

Ten (7%) of 153 patients had cryptosporidiosis, 54 (37%) had isosporiasis and 23 (16%) had microsporidiosis. By 3 weeks, these protozoa were cleared in 27 (46%) of 59 patients initially positive. By 6 weeks, 34 (39%) of 87 patients experienced complete clinical response, 18 (21%) partial response and 35 (40%) no response. Crypt depth increased by 15% over 6 weeks (P < 0.001), but villous height increased only in patients with complete response (median + 50 microm, interquartile range (IQR) 2-90, compared to patients with partial (+ 4 microm, IQR -15,41) or no response (-13 microm, IQR -2,12; P=0.008)). Fifteen patients died: body mass index < 17.5 kg/m(2) and crypt depth < 180 microm independently predicted death.

CONCLUSIONS

Albendazole therapy reduced the burden of protozoal infection and promoted mucosal recovery in patients with a complete clinical response.

The role of exercise in the prevention and treatment of wasting in acquired immune deficiency syndrome

Involuntary weight loss with lean tissue depletion is a serious and AIDS-defining complication of HIV infection. This article explores definitions of AIDS wasting syndrome (AWS), its etiology, methods of assessing body composition, and pharmacological treatments. Recent research literature on the role of exercise in the prevention and treatment of AWS is reviewed. Included are studies of the safety of exercise, the effects of exercise on the immune system, and the effects of exercise on weight gain and body composition as well as studies of exercise in combination with medications and other interventions. Implications for clinical practice are discussed.

Nutrition and HIV infection

Infection by the human immunodeficiency virus (HIV) is characterized by progressive destruction of the immune system, which leads to recurrent opportunistic infections and malignancies, progressive debilitation and death. Malnutrition is one major complication of HIV infection and is recognized as a significant prognostic factor in advanced disease. Malnutrition is multifactorial and poorly treated during the course of HIV. Even if a standardized approach to the management of active weight loss has not been well established, early nutritional intervention is important in HIV infected patients to maximize gain of lean body mass. From early in the era of highly active antiretroviral therapy (HAART), an initial decreased incidence of malnutrition was noted only in western countries while a variety of changes in the distribution of body fat and associated metabolic abnormalities have been recognized under the banner of lipodystrophy.

Maternal and infant factors associated with failure to thrive in children with vertically transmitted human immunodeficiency virus-1 infection: the prospective, P2C2 human immunodeficiency virus multicenter study

OBJECTIVE

Many children with human immunodeficiency virus-1 (HIV-1) have chronic problems with growth and nutrition, yet limited information is available to identify infected children at high risk for growth abnormalities. Using data from the prospective, multicenter P2C2 HIV study, we evaluated the relationships between maternal and infant clinical and laboratory factors and impaired growth in this cohort.

METHODS

Children of HIV-1-infected women were enrolled prenatally or within the first 28 days of life. Failure to thrive (FTT) was defined as an age- and sex-adjusted weight z score < or =-2.0 SD. Maternal baseline covariates included age, race, illicit drug use, zidovudine use, CD4+ T-cell count, and smoking. Infant baseline predictors included sex, race, CD4+ T-cell count, Centers for Disease Control stage, HIV-1 RNA, antiretroviral therapy, pneumonia, heart rate, cytomegalovirus, and Epstein-Barr virus infection status.

RESULTS

The study cohort included 92 HIV-1-infected and 439 uninfected children. Infected children had a lower mean gestational age, but birth weights, lengths, and head circumferences in the 2 groups were similar. Mothers of growth-delayed infants were more likely to have smoked tobacco and used illicit drugs during pregnancy. In repeated-measures analyses of weight and length or height z scores, the means of the HIV-1-infected group were significantly lower at 6 months of age (P <.001) and remained lower throughout the first 5 years of life. In a multivariable Cox regression analysis, FTT was associated with a history of pneumonia (relative risk [RR] = 8.78; 95% confidence interval [CI]: 3.59-21.44), maternal use of cocaine, crack, or heroin during pregnancy (RR = 3.17; 95% CI: 1.51-6.66), infant CD4+ T-cell count z score (RR = 2.13 per 1 SD decrease; 95% CI: 1.25-3.57), and any antiretroviral therapy by 3 months of age (RR = 2.77; 95% CI: 1.16-6.65). After adjustment for pneumonia and antiretroviral therapy, HIV-1 RNA load remained associated with FTT in the subset of children whose serum was available for viral load analysis.

CONCLUSIONS

Clinical and laboratory factors associated with FTT among HIV-1-infected children include history of pneumonia, maternal illicit drug use during pregnancy, lower infant CD4+ T-cell count, exposure to antiretroviral therapy by 3 months of age (non-protease inhibitor), and HIV-1 RNA viral load.

Natural and iatrogenic factors in human immunodeficiency virus transmission

In the light of the evidence and discussion presented during The Royal Society Discussion Meeting it seems to me that the oral polio vaccine (OPV) hypothesis for the origins of human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome epidemic is less tenable now than one year earlier. The OPV hypothesis does not accord with HIV phylogenetic studies: the geographical correlation has been challenged; the testimony of those directly involved with OPV trial vaccines denies the use of chimpanzees, corroborating tests on the still-available vials of the CHAT vaccines, which contain neither simian immunodeficiency virus nor chimpanzee DNA. Yet one lesson to be learned from considering OPV as a source of HIV is how plausibly it might have happened and how cautious we need to be over introducing medical treatments derived from animal tissues, such as live, attenuated vaccines or xenotransplantation. To cast doubt on the OPV hypothesis is not to dismiss entirely the role of iatrogenic factors in HIV transmission from chimpanzees in the first instance, in HIV adaptation to onward transmission during its early phase in humans, or in the later spread of HIV to patients, for example, with haemophilia. To reduce the argument over the origins of HIV to the 'OPV hypothesis' versus the 'cut-hunter hypothesis' is an oversimplistic and false antithesis. Both natural and iatrogenic transmission of many retroviruses, including HIV, have been thoroughly documented and are not mutually exclusive. Exactly how, when and where the first human(s) became infected with the progenitor of HIV-1 group M, which gave rise to the pandemic strain, is likely, however, to remain a matter of conjecture.

The Leeuwenhoek Lecture 2001. Animal origins of human infectious disease

Since time immemorial animals have been a major source of human infectious disease. Certain infections like rabies are recognized as zoonoses caused in each case by direct animal-to-human transmission. Others like measles became independently sustained with the human population so that the causative virus has diverged from its animal progenitor. Recent examples of direct zoonoses are variant Creutzfeldt-Jakob disease arising from bovine spongiform encephalopathy, and the H5N1 avian influenza outbreak in Hong Kong. Epidemics of recent animal origin are the 1918-1919 influenza pandemic, and acquired immune deficiency syndrome caused by human immunodeficiency virus (HIV). Some retroviruses jump into and out of the chromosomal DNA of the host germline, so that they oscillate between being inherited Mendelian traits or infectious agents in different species. Will new procedures like animal-to-human transplants unleash further infections? Do microbes become more virulent upon cross-species transfer? Are animal microbes a threat as biological weapons? Will the vast reservoir of immunodeficient hosts due to the HIV pandemic provide conditions permissive for sporadic zoonoses to take off as human-to-human transmissible diseases? Do human infections now pose a threat to endangered primates? These questions are addressed in this lecture.

Anthropometric indices as predictors of survival in AIDS adults. Aquitaine Cohort, France, 1985-1997. Groupe d'Epidémiologie Clinique du Sida en Aquitaine (GECSA)

The aim of the study was to assess the performance of weight related nutritional markers [reported involuntary weight loss (WL) greater than 10%, measured WL and body mass index (BMI)] in predicting survival at AIDS stage. The three anthropometric indices were used as time dependent variables in Cox models to predict survival at AIDS stage. The studied sample included 630 HIV1-infected individuals of a prospective cohort of those 421 died (median survival at AIDS stage: 19.9 months). After adjustment for usual prognostic factors of survival, the reported WL greater than 10% was a pejorative predictor of survival (hazard ratio (HR) 2.4; 95% confidence interval (CI): 1.9-3.0). For measured WL < 5%, between 5 and 10% and > or = 10% of baseline weight compared with no WL, HR were respectively, 1.9 (CI: 1.4-2.6), 3.3 (CI: 2.4-4.4) and 6.7 (CI: 5.2-8.6). The HR of death were 2.2 (CI: 1.6-3.0) for BMI between 16 and 18.4 kg/m2 and 4.4 (CI: 3.1-6.3) for BMI < 16 compared to normal BMI (> or = 18.5). Even a limited WL measured at a given point in time during follow up increases the risk of death at the AIDS stage. Simple cross-sectional measures of BMI have a good predictive value of survival.

Prevalence and predictive value of overweight in an urban HIV care clinic

OBJECTIVE

To determine the prevalence and predictive value of overweight in an urban HIV clinic.

METHODS

Medical records of all new adult, nonpregnant registrants in 1996 in an urban HIV clinic with at least one height and weight measurement were reviewed. Body mass index (BMI) at clinic enrollment was calculated, and prevalence of overweight was thus determined. The subsequent clinical course of the overweight group was compared with that of a randomly selected group of gender-stratified non-overweight patients.

RESULTS

At baseline, 12.6% of men and 32.5% of women were overweight. Female gender and lack of AIDS diagnosis were independently associated with overweight. More than one half of women and 19.6% of men were overweight at some point during the study. Providers were more likely to properly acknowledge underweight than overweight. Among patients without AIDS, there was a trend toward slower disease progression and lower viral load in overweight patients, despite similar baseline CD4+ lymphocyte counts and similar time to initiation of highly active antiretroviral therapy. In multivariate proportional hazards analyses, lower baseline BMI and falling BMI during follow-up were independently predictive of progression to AIDS.

CONCLUSIONS

Overweight was a common and underrecognized finding, particularly among women. Overweight patients may progress more slowly to AIDS than non-overweight patients.

Emerging concepts in gastrointestinal aspects of HIV-1 pathogenesis and management

GASTROENTROLOGY 2001;120:607-621

Body composition in HIV-infected women

Although loss of lean body mass is a common complication of human immunodeficiency virus (HIV) infection that can occur across the disease trajectory, few studies have characterized the body composition of HIV-infected women. We used bioelectrical impedance analysis to characterize the body composition of HIV-infected (n = 56) and uninfected (n = 12) women who were matched on percentage of ideal body weight. The HIV-infected women did not differ from the uninfected women by height-adjusted fat mass or body cell mass. Intergroup comparisons among the HIV-infected women showed that underweight women had significantly less fat mass than did normal-weight women but did not significantly differ with respect to body cell mass. Among all HIV-infected women, CD4(+) lymphocyte count was positively correlated with fat mass (r = 0.32, P = 0.01) but not with body cell mass. No significant correlations were found between any body-composition parameter and plasma viral load. Our findings suggest that, unlike men, HIV-infected underweight women show a preferential loss of fat mass and a relative preservation of body cell mass. This altered pattern of weight loss may relate to higher premorbid fat stores in women and/or hormonal differences.

Mortality associated with HIV infection in rural Rakai District, Uganda

OBJECTIVE

To assess mortality impact of HIV in rural Uganda.

METHODS

An open cohort of 19983 adults aged 15-59 years, in Rakai district was followed at 10 month intervals for four surveys. Sociodemographic characteristics and symptomatology/disease conditions were assessed by interview. Deaths among residents and out-migrants were identified household census. Mortality rates were computed per 1000 person years (py) and the rate ratio (RR) of death in HIV-positive/HIV-negative subjects, and the population attributable fraction (PAF) of death were estimated according to sociodemographic characteristics. Mortality associated with potential AIDS defining symptoms and signs was assessed.

RESULTS

HIV prevalence was 16.1%. Mortality was 132.6 per 1000 py in HIV-infected versus 6.7 per 1000 py in uninfected subjects, and 73.5% of adult deaths were attributable to HIV infection. Mortality increased with age, but the highest attributable risk of HIV associated deaths were observed in persons aged 20-39 years (PAF > 80%) and in women. HIV associated mortality was highest in the better educated (PAF > or = 75%) and among government employees (PAF > or = 82%). Of the HIV-positive subjects 40.5% reported no illness < 10 months preceding death, symptoms were poor predictors of death (sensitivity 1.6-38.8%), and only 9.1% met the World Health Organization clinical definition of AIDS. Infant mortality rates in babies of HIV-infected and uninfected mothers were 209.4 and 97.7 per 1000, respectively.

CONCLUSION

HIV is taking substantial toll in this population, particularly among the younger better educated adults, and infants. Symptomatology or the World Health Organization definition of AIDS are poor predictors of death.

Getting to know HIV

Since the Human Immunodeficiency Virus was first isolated in 1983, we have come to know it in exquisite detail. Yet we still do not understand sufficiently how it causes disease. Neither do we know why chimpanzees and some African monkeys, which are the natural reservoir of the precursors of HIV-1 and HIV-2, can harbour similar levels of virus without becoming ill. Our knowledge of the replication cycle of HIV as a retrovirus has been pivotal in the development of antiviral drugs. Our knowledge of the cellular tropism and cell surface receptors exploited by the virus help to explain the pattern of immune deficiency, wasting and dementia that make up the clinical dimensions of AIDS. The extraordinary rate of genetic and phenotypic evolution of the virus - both within the infected individual and across the worldwide pandemic - partially explains why no vaccine constructs to date have been successful. HIV comprises just 9 genes but represents one of humanity's most formidable foes.

Royal Society of Tropical Medicine and Hygiene meeting at Manson House, London, 18 March 1999. Fresh from the field: some controversies in tropical medicine and hygiene. HIV and malaria, do they interact?

Malaria and human immunodeficiency virus (HIV) infections are common, widespread and overlapping problems in the tropics. Despite this there has been minimal evidence to support an important interaction, other than during pregnancy in multigravid HIV-infected women. The lack of an interaction in other groups is surprising, and would be unexpected based on present knowledge of anti-malarial immunity. However, most of the reported studies have been cross-sectional and performed in selected groups, making their findings difficult to interpret. Two cohort studies in children were similarly inconclusive, although both hinted at a decreased ability to control parasitaemia with more advanced HIV-disease. Recent work from Entebbe carried out in a well-characterized cohort of HIV-infected adults revealed an increase in malarial fever with deteriorating immune status. Rates by CD4+ T-cell count groups > 500, 200-499 and < 200 cells/microL were 45, 73 and 115 cases per 1000 person-years respectively, P < 0.01 for trend. These findings support an important interaction between HIV and malaria. The public health consequences and the relevance of these findings out with Entebbe are uncertain. The importance of understanding this interaction further must be a priority for sub-Saharan Africa: consequently further studies designed primarily to answer these questions will be necessary. Meanwhile, the optimism that the global malaria situation was largely unaffected by the HIV pandemic may need to be reconsidered.

Molecular epidemiology of HIV type 1 in a rural community in southwest Uganda

The molecular epidemiology of a population-based cohort in a cluster of 15 villages in southwestern Uganda was investigated by sequencing part of the p24 gag gene and performing heteroduplex mobility assays (HMAs) of the V3 region of the env gene. Sequence and HMA data, obtained for 69 and 88 proviruses, respectively, showed that the clade A and D viruses were present at a ratio of about 0.67:1. No other clades were detected. Thirteen (22%) of 59 proviruses for which both gag and env data were obtained appeared to be recombinants. Although both clade A and D viruses were present in 13 of the villages, their distribution was unequal: for example, from env data 59% of clade A viruses were found in the eastern villages, compared with only 27% of clade D viruses. Phylogenetic (maximum likelihood) analysis of the p24 gag sequences showed a total of five clusters supported by bootstrap resampling values above or close to 75%. Four clusters were sexual partners, but there was no known sexual contact between the persons in the other cluster. The DNA sequences showed between 0.5 and 8.3% divergence from the cohort clade A or D consensus sequences. The sequences were not closely related to those published for other clade A or D proviruses.

When obesity is desirable: a longitudinal study of the Miami HIV-1-infected drug abusers (MIDAS) cohort

Despite widespread nutrient deficiencies, a substantial proportion of the MIDAS cohort exhibits obesity, which has been linked to immune dysregulation in other clinical settings. Herein, the effects of obesity on immune function, disease progression, and mortality were evaluated longitudinally in 125 HIV-1-seropositive drug users, with comparison measures in 148 HIV-1-seronegative controls. Data were collected at a community clinic from 1992 to 1996, before administration of highly active antiretroviral therapy. Results indicated that overweight/obesity, defined as body mass index (BMI; kg/m2) > or =27, was evident in 18% of the HIV-1-seropositive patients and 29% of the seronegative patients. At baseline, no significant immunologic differences were observed among lean, nonobese, and obese groups. Over an 18-month period, 60.5% of the nonobese HIV-1-seropositive patients exhibited a 25% decline in CD4 cell count, compared with 18% of the obese patients (p<.004). During the follow-up period, 38% of the lean and 13% of the nonobese study subjects died of HIV-1-related causes. Measurements of BMI were inversely associated with progression to death, independent of CD4 count <200 cells/mm3 (p<.02). These data suggest that mild-to-moderate obesity in HIV-1-infected chronic drug users does not impair immune function and is associated with better HIV-1-related survival.

Epidemiology and management of diarrheal disease in HIV-infected patients

Diarrhea is the most common gastrointestinal symptom in human immunodeficiency virus (HIV) infection. It affects up to 90% of patients, becoming more frequent and severe as the immune system deteriorates. It often is associated with significant morbidity and mortality particularly in the developing countries. Gastrointestinal infections, some of which are attributable to inadequate sanitation and poor hygiene are the predominant cause of diarrhea, although multiple medications, including traditional herbs, also may be causes. The basic principles of management include detection of treatable causes, relief of symptoms, prevention of malnutrition, and psychosocial support. In up to 60% of cases, no cause can be identified, partly because of inadequate investigative facilities. Symptomatic treatment is the mainstay of management particularly when no cause can be identified. Unfortunately this can be extremely difficult when the patient is severely immune-suppressed. There is poor response to motility control drugs, such as loperamide, and others, such as octreotide, are too expensive. Fluid replacement should be started early to prevent excessive dehydration. This should be combined with nutritional support to prevent malnutrition. Psychosocial support, including counselling, for both the patient and the caring relatives, is required to alleviate anxiety, particularly when the diarrhea becomes intractable.

Malnutrition in tuberculosis

Tuberculosis has a dramatic effect on nutritional state and this has been borne out in all the studies that have investigated body composition in affected patients. I have included some of the key studies in this review; those I have not cited generally reach the same conclusions. Such malnutrition undoubtedly contributes to the morbidity of the disease and may also contribute to mortality, particularly in resource-poor settings where nutritional state, even in the "healthy," may be parlous. The extent to which such malnutrition also contributes to pathology remains unclear. Certainly, in other models, nutritional depletion has a major impact on immune function (Chandra, 1997) and depression of lymphocyte function cannot be a desirable commodity in an individual fighting invasive mycobacterial infection. Considering the reverse relationship, there is good evidence, both at the population level and at the clinical level, for the effect of primary malnutrition on tuberculosis, both to increase frequency of occurrence and to exacerbate clinical manifestations. It has not been possible to explore this relationship within the context of this paper but it is clearly an important aspect of the bi-directional relationship between tuberculosis and malnutrition. There is still more to be understood about the pathophysiology of the wasting seen in chronic infections such as tuberculosis but it is clear that, in addition to good anti-tuberculous therapy, such patients need a good supply of nutrition during the treatment/recovery phase. In the developed world, this may include medical measures to achieve nutritional support whereas in resource-poor settings, nutritional intake may have more to do with equitable resource distribution and community involvement in health care.

Comparison of intestinal function in human immunodeficiency virus-seropositive patients in Kampala and London

BACKGROUND

White homosexual men with human immunodeficiency virus (HIV) show progressive impairment of intestinal function assessed in terms of intestinal permeability and absorptive capacity. In this study we aimed to determine the effects of heterosexually acquired HIV on small-intestinal function in native Africans, among whom there is a high prevalence of tropical enteropathy.

METHODS

Intestinal absorptive capacity (using 3-O-methyl-D-glucose, D-xylose, and L-rhamnose) and permeability (differential 5-h urinary excretion of lactulose/L-rhamnose) were assessed in healthy white (n = 57) and black (n = 14) controls in London, apparently healthy black Africans in Kampala, Uganda (n = 26), HIV-infected patients with (n = 9) and without (n = 30) diarrhoea in Kampala, and 39 white homosexual men with HIV in London who were stratified to resemble the African patient group.

RESULTS

Intestinal integrity and absorptive capacity were significantly (P < 0.01) impaired in both black controls in London and apparently healthy black Africans, compared with white controls. HIV-infected white and black patients without diarrhoea did not differ significantly from white and black African controls, respectively, with the exception of increased intestinal permeability among the white patients. White and black African patients with HIV/acquired immunodeficiency syndrome (AIDS) and diarrhoea were found to have marked malabsorption and increased intestinal permeability. Although the relative increase in intestinal permeability was similar in the two groups, by far the largest values for intestinal permeability were found among black Africans with HIV/AIDS and diarrhoea.

CONCLUSIONS

Whites and blacks differ with regard to intestinal barrier function. HIV-positive black Africans without gastrointestinal symptoms differ insignificantly from white Londoners with homosexually acquired disease, whereas those with gastrointestinal symptoms have markedly abnormal indices of small-intestinal function with severely comprised intestinal integrity.

Chronic diarrhoea among HIV-infected adult patients in Nairobi, Kenya

OBJECTIVES

Chronic diarrhoea and wasting are well recognized features of AIDS in Africa. However, because of resource constraints few comprehensive aetiological studies have been conducted in sub-Saharan Africa which have included a broad range of microbiological investigations. We undertook a prospective cross-sectional study of adult patients admitted to a government hospital in Nairobi, Kenya, to determine possible bacterial, mycobacterial, parasitic and viral causes of diarrhoea; to consider which may be treatable; and to relate microbiological findings to clinical outcome.

METHODS

Stool specimens from 75 consecutive HIV-seropositive patients with chronic diarrhoea admitted to a Nairobi hospital were subjected to microbiological investigation and results were compared with clinical findings and outcome. Stool samples were cultured for bacteria and mycobacteria and underwent light and electron microscopy; lawns of Escherichia coli were probed for pathogenic types and aliquots were tested for the presence of Clostridium difficile cytotoxin. Blood cultures for mycobacteria and other bacterial pathogens were performed as clinically indicated.

RESULTS

Thirty-nine (52%) patients yielded putative pathogens, the most common being Cryptosporidium sp. (17%), Salmonella typhimurium (13%), and Mycobacterium tuberculosis (13%). Of 41 patients investigated for pathogenic Escherichia coli, enteroaggregative E. coli and diffusely adherent E. coli were each found in four patients. Thirty-one (41%) patients died. Detection of cryptosporidium cysts was the single most significant predictor of death (X2 = 5.2, P<0.05). Many patients did not improve (21; 28%) or self-discharged whilst still sick (5; 7%) but five (7%) were diagnosed ante mortem with tuberculosis and treated and a further 13 (17%) showed improvement by time of discharge.

CONCLUSIONS

HIV-infected patients with chronic diarrhoea in Nairobi have a poor outcome overall, and even with extensive investigation a putative pathogen was identified in only just over half the patients. The most important step is to exclude tuberculosis; and the most useful investigation appears to be Ziehl-Neelsen staining. Other potentially treatable gram-negative bacterial pathogens, S. typhimurium, Shigella sp. and adherent E. coli were, however, common but require culture facilities which are not widely accessible for definitive identification. Further studies focussing on simple ways to identify sub-groups of patients with treatable infections are warranted.

HIV wasting syndrome: treatment update

OBJECTIVE

To review the pathophysiology and treatment of HIV wasting syndrome.

DATA SOURCES AND STUDY SELECTION

MEDLINE searches (January 1987-September 1997) of the English-language medical literature were conducted. Bibliographies were also selected during a manual review.

DATA SYNTHESIS

HIV-related weight loss, often referred to as HIV wasting syndrome, is a common manifestation of advanced HIV infection. Wasting in HIV involves the preferential loss of lean body mass with a paradoxical preservation of body fat. The etiology of wasting appears to be the result of many factors, which may include decreased caloric intake, malabsorption, alterations in energy expenditure and metabolism, cytokine effects, and endocrine dysfunction. Pharmacologic treatment options include appetite stimulants (e.g., dronabinol, megestrol acetate), cytokine inhibitors (e.g., thalidomide, cyproheptadine, ketotifen, pentoxifylline, fish oil, N-acetylcysteine), and anabolic agents (e.g., testosterone, nandrolone, oxandrolone, recombinant human growth hormone).

CONCLUSIONS

Wasting associated with HIV has a high morbidity and mortality rate if not adequately managed. Therapeutic strategies include appetite stimulants, cytokine inhibitors, and growth-promoting agents. Selection of the appropriate agent(s) depends on the underlying cause for weight loss, adverse effects, and cost of therapy.

Direct effect of type 1 human immunodeficiency virus (HIV-1) on intestinal epithelial cell differentiation: relationship to HIV-1 enteropathy

Human immunodeficiency virus (HIV)-infected patients display severe impairments of gastrointestinal functions, including diarrhea and malabsorption, even in the absence of opportunistic infections. Since HIV-1 proteins and nucleic acids have been detected in several cell types of the intestinal mucosa, it has been postulated that HIV-1 itself could alter enterocytic functions. In the present study, we analyzed the effect of HIV-1 on the differentiation process of the epithelial intestinal cell clone HT-29-D4, which mimics the maturation of enterocytes along the crypt-villus axis of the small intestine. We found that HIV-1 infection impairs cellular differentiation (i) by affecting the barrier function of the epithelium, as evidenced by a decrease in the transepithelial electrical resistance, and (ii) by inhibiting the activity of one major glucose absorption function, i.e., sodium/glucose cotransport. At the morphological level, HIV-1 infection of HT-29-D4 cells was associated with the formation of lumina, which are representative of a defect in cellular organization. These morphofunctional perturbations induced by HIV-1 could be mimicked by nocodazole, a microtubule-disrupting agent. Correspondingly, HIV-1 exposure of HT-29-D4 cells evoked a massive disruption of microtubules, as revealed by alpha-tubulin indirect immunofluorescence staining. A similar effect was observed after incubation of the cells with either recombinant gp120 or a monoclonal antibody against galactosylceramide (GalCer), the intestinal receptor for HIV-1 gp120, suggesting that the effect of HIV-1 was mediated by the binding of gp120 to GalCer. Based on these data, we propose that HIV-1 may selectively alter enterocytic functions through a direct effect on the intracellular architecture of the cells. In contrast with previous theories for HIV-1 enteropathy, our data support the concept that HIV-1 may perturb intestinal functions without necessarily infecting intestinal epithelial cells.

Therapeutic options for HIV-associated bodyweight loss. A risk-benefit analysis

Involuntary bodyweight loss, a common complication of infection with HIV, is an indicator of poor prognosis and decreased survival. Because of the multifactorial pathogenesis of HIV-related wasting, emerging therapies are directed at the multiple proposed mechanisms of involuntary bodyweight loss. The initial evaluation and treatment of HIV-related bodyweight loss is focused on the identification and treatment of reversible causes of bodyweight loss, such as secondary opportunistic infections or endocrine dysfunction. Nutritional intervention should begin in the early stages of HIV infection and continue throughout the life of the patient. Of the appetite stimulants, megestrol most consistently promotes bodyweight gain, but with a predominance of fat, not lean, body mass. Anabolic therapies such as testosterone derivatives and recombinant human growth hormone (somatropin) stimulate the addition of lean body mass and are begin actively researched for the treatment of HIV-associated wasting. Finally, thalidomide, a potent inhibitor of tumour necrosis factor-alpha, is a potentially useful therapy that is still under investigation. New research into the treatment of HIV-related bodyweight loss is focusing on combination therapies.

Responsiveness of muscle protein synthesis to growth hormone administration in HIV-infected individuals declines with severity of disease

This study was undertaken to determine if human recombinant growth hormone (hrGH, 6 mg/d for 2 wk) would stimulate muscle protein synthesis in AIDS wasting. Healthy controls were compared with patients who were HIV+, had AIDS without weight loss, and had AIDS with > 10% weight loss. Before hrGH, rates of skeletal muscle protein synthesis, measured with l-[2H5]phenylalanine, were the same in controls and in all stages of disease. Rates of myofibrillar protein degradation, however, assessed from urinary excretion of 3-methyl histidine, were higher in AIDS and AIDS wasting than in HIV+ or healthy individuals. The group with weight loss had significantly higher TNFalpha levels but not higher HIV viral loads. Muscle function, as determined by isokinetic knee extension and shoulder flexion, was significantly higher in controls than all infected individuals. After GH, rates of protein synthesis were stimulated 27% in controls, with a smaller increase (11%) in HIV+, and a significant depression (42%) in AIDS with weight loss, despite fourfold elevation in insulin-like growth factor-I in all groups. There was a significant correlation of hrGH-induced changes in muscle protein synthesis with severity of disease (P = 0.002). The results indicate increased basal muscle protein degradation and decreased responsiveness of muscle protein synthesis to GH in the later stages of disease.

HIV and medical nutrition therapy

In those who are infected with human immunodeficiency virus, poor nutritional status can result from numerous causes, including anorexia, catabolism, chronic infection, fever, poor nutrient intake, nausea, vomiting, diarrhea, malabsorption, metabolic disturbances, lack of access to food, depression, and side effects of drug, radiation, and chemotherapy treatments. A compromised immune system may not be reversed by any medical treatments at this time, but malnutrition may be prevented and reversed by using current therapies, including medical nutrition therapy that includes nutrition assessment, the development of an individualized nutrition therapy plan, and implementation of the therapy. There is substantial evidence that medical nutrition therapy saves lives, reduces morbidity, improves health outcomes, reduces costs, and shortens hospital stays.

AIDS and HIV infection in Sudanese children: a clinical and epidemiological study

HIV surveillance and screening programs were established at Khartoum Teaching Hospital (KTH) following the first identified HIV case diagnosed in a hemophiliac boy in November 1987. As of December 1995, 15 cases of symptomatic HIV infection have been observed in Sudanese children (< or = 16 years) at KTH. An HIV seroprevalence rate of 35.7% was documented in a group of 28 patients (adults and children) with various congenital coagulation defects. The postulated mode of transmission was through contaminated factor concentrate. Screening of 52,000 volunteer male blood donors (March, 1987-1989) showed an HIV-seroprevalence rate of 0.05%. Selected groups, including 1118 children admitted to KTH during the period 1985-1995, were screened for HIV infection. These included aseptic meningitis/encephalitis group (n = 52), high-risk group (n = 523), children with various chronic and malignant diseases (n = 181), and chronic blood recipients (n = 330). A group of 32 displaced homeless children who survived on the streets were also included. Overall, an HIV seroprevalence rate of 1.2% was established. Among the 15 children with symptomatic HIV infection, tuberculosis accounted for the majority of admissions (33.3%) followed by admission for recurrent infections (20.0%). Of the 13 children with nonparental mode of HIV transmission, a vertical mode was documented in 61.5%. The pattern of HIV infection in Greater Khartoum is similar to that in North Africa and the Middle East. However, the geographic influence of high endemicity in neighboring sub-Saharan countries might change it in the future.

High risk of HIV-related mortality is associated with selenium deficiency

To determine the independent contribution of specific immunologic and nutritional factors on survival in HIV-1 disease, CD4 cell count, antiretroviral treatment, plasma levels of vitamins A, E, B6, and B12 and minerals selenium and zinc were considered in relation to relative risk for HIV-related mortality. Immune parameters and nutrients known to affect immune function were evaluated at 6-month intervals in 125 HIV-1-seropositive drug-using men and women in Miami, FL, over 3.5 years. A total of 21 of the HIV-1-infected participants died of HIV-related causes during the 3.5-year longitudinal study. Subclinical malnutrition (i.e., overly low levels of prealbumin, relative risk [RR] = 4.01, p < 0.007), deficiency of vitamin A (RR = 3.23, p < 0.03), vitamin B12 deficiency (RR = 8.33, p < 0.009), zinc deficiency (RR = 2.29.1, p < 0.04), and selenium deficiency (RR = 19.9, p < 0.0001) over time, but not zidovudine treatment, were shown to each be associated with HIV-1-related mortality independent of CD4 cell counts <200/mm3 at baseline, and CD4 counts over time. When all factors that could affect survival, including CD4 counts <200/mm3 at baseline, CD4 levels over time, and nutrient deficiencies were considered jointly, only CD4 counts over time (RR = 0.69, p < 0.04) and selenium deficiency (RR = 10.8, p < 0.002) were significantly associated with mortality. These results indicate that selenium deficiency is an independent predictor of survival for those with HIV-1 infection.

HIV-1 disease progression and AIDS-defining disorders in rural Uganda

BACKGROUND

The majority of people infected with HIV-1 live in Africa, yet little is known about the natural history of the disease in that continent. We studied survival times, disease progression, and AIDS-defining disorders, according to the proposed WHO staging system, in a population-based, rural cohort in Uganda.

METHODS

In 1990 we recruited a random sample of people already infected with HIV-1 (as prevalent cases) detected during the initial survey round of a general-population study to form a natural-history cohort. Individuals from the general-population cohort who seroconverted between 1990 and 1995 (incident cases) were also invited to enroll. Participants were seen routinely every 3 months and when they were III.

FINDINGS

By the end of 1995, 93 prevalent cases and 86 incident cases had been enrolled. Four patients in the prevalent group were in stage 4 (AIDS) at the initial visit. During the next 5 years, 37 prevalent cases progressed to AIDS. Seven incident cases progressed to AIDS and the cumulative progression to AIDS at 1, 3, and 5 years after seroconversion was 2%, 6%, and 22%, respectively. The cumulative probability of AIDS at 4 years from entering stages 1, 2, and 3 was 11%, 33%, and 58%, respectively. There were 47 deaths among prevalent cases and seven among incident cases during follow-up. The cumulative mortality 4 years after patients entered stages 1, 2, 3, and 4 was 9%, 33%, 56%, and 86%, respectively. The median survival after the onset of AIDS was 9.3 months.

INTERPRETATION

Our results are important for the setting of priorities and rationalisation of treatment availability in countries with poor resources. We found that progression rates to AIDS are similar to those in developed countries for homosexual cohorts and greater than for cohorts infected by other modes of transmission. However, we have found that the rates of all-cause mortality are much higher and the progression times to death are shorter than in developed countries.

Nutritional support of the hospitalized patient

Comprehensive care of patients in hospitals includes assessment of nutritional status and provision of appropriate support. This approach is facilitated by knowledge of the essential differences in metabolism between starved and stressed states. Nutritional assessment and care of patients in a hospital are based on answers to the following questions: Who gets it? When do they get it? How much do they get? What route is used to administer it? What kind do they get? What are common complications of enteral and parenteral support? What nutritional aspects are pertinent to common diseases?

Empirical evidence for the severe but localized impact of AIDS on population structure

Despite considerable speculation on the demographic impact of AIDS, there has been, until now, little scientific evidence to establish its existence or scale. Because of the widespread implications of these predictions, methods to combine demography and epidemiology to study empirical situations have been an urgent priority. This study derives the extent and mechanisms of demographic impacts of AIDS from routine data (the 1991 census) in a severely affected country, Uganda. Three characteristics are of particular note: first, the emergence of demographic impacts much earlier than previously estimated; second, their localization with negative population growth at parish but not at district or national scales; third, a greater impact on the number of children than previously predicted, due as much to changes in population fertility as mortality. The emergence of demographic impacts at this stage highlights original aspects of the interdependence of HIV infection and demographic growth not previously recorded and the need to target preventive interventions to youth in developing countries.

Cryptosporidiosis in Houston, Texas. A report of 95 cases

Cryptosporidiosis is an important cause of diarrhea. We identified 95 patients with cryptosporidiosis over a 6-year period in our county hospital system, including 9 children and 86 adults infected with the human immunodeficiency virus (HIV). Risk factors included male-to-male sexual practices and Hispanic race. Diarrhea, weight loss, and gastrointestinal complaints were the most common symptoms at presentation. Among the HIV-infected adults, 20 (23%) developed biliary tract disease. Biliary involvement was associated with low CD4 counts. Treatment with paromomycin and antimotility agents was effective in reducing diarrheal symptoms in 54 of 70 (77%) patients with the acquired immunodeficiency syndrome (AIDS), although there was a high rate of relapse. Paromomycin did not prevent the development of biliary disease. Biliary disease responded to cholecystectomy or sphincterotomy with stent placement. Though often a cause of morbidity, cryptosporidiosis was only rarely the cause of death, even among patients with HIV. Cryptosporidiosis continues to be an important medical problem even in developed-countries. Current methods of prevention and treatment are suboptimal.

Pediatric human immunodeficiency virus infection

In the past decade, an increase in pediatric human immunodeficiency virus (HIV) infection has had a substantial impact on childhood morbidity and mortality worldwide. The vertical transmission of HIV from mother to infant accounts for the vast majority of these cases. Identification of HIV-infected pregnant women needs to be impoved so that appropriate therapy can be initiated for both mothers and infants. While recent data demonstrate a dramatic decrease in HIV transmission from a subset of women treated with zidovudine during pregnancy, further efforts at reducing transmission are desperately needed. This review focuses on vertically transmitted HIV infection in children, its epidemiology, diagnostic criteria, natural history, and clinical manifestations including infectious and noninfectious complications. An overview of the complex medical management of these children ensues, including the use of antiretroviral therapy. Opportunistic infection prophylaxis is reviewed, along with the important role of other supportive therapies.

Causes of chronic diarrhea in patients with AIDS in Thailand: a prospective clinical and microbiological study

A prospective study was designed to investigate the causes of chronic diarrhea in AIDS patients in Thailand. Forty-five patients from Bamrasnaradura Infectious Diseases Hospital were enrolled. Extensive investigations included multiple stool examinations for ova and parasites, using the stool formalin-ether concentration method, stool culture, stool acid-fast bacilli (AFB) stain, stool modified AFB stain, esophagogastroduoscopy with duodenal aspirate and biopsy, and colonoscopy with biopsy. Biopsied specimens were examined with H&E, Giemsa, Gram, Periodic acid Schiff, and AFB stains. Definitive causes were found in 29 patients (64.4%). Of these 29, 7 patients were found to habor more than 1 pathogen (15.5%). The most commonly found enteric pathogen was Cryptosporidium parvum (20.0%). Less frequently found pathogens were Mycobacterium tuberculosis (17.8%), Salmonella spp. (15.5%), Cytomegalovirus (11.1%), Mycobacterium avium intracellulare (6.6%), Strongyloides stercoralis (4.4%), Giardia lamblia (4.4%), Cryptococcus neoformans (2.2%), Histoplasma capsulatum (2.2%), Campylobacter jejun (2.2%), and Cyclospora cayetanensis (2.2%). Salmonella spp., Mycobacterium tuberculosis, and Mycobacterium avium intracellulare infections were shown to be more common in Thailand than in African countries.

Clinical predictors of functioning in persons with acquired immunodeficiency syndrome

To help clinicians better assess and treat functional disabilities in persons with acquired immunodeficiency syndrome (AIDS), the authors estimate empirical relations among biologic and physiologic variables, symptoms, and physical functioning in persons with AIDS. The sample of 305 persons with AIDS for this cross-sectional analysis came from three sites in Boston, Massachusetts: a hospital-based group practice, a human immunodeficiency virus clinic at a city hospital, and a staff-model health maintenance organization. Physical functioning, 10 AIDS-specific symptoms, and mental health were assessed by interview. Clinical diagnoses, comorbidities, health habits such as smoking, laboratory results, and selected medication use were assessed by chart review. Significant predictors of physical functioning P < 0.01, R2 = .58) in a multivariable regression model included energy/fatigue, neurologic symptoms, fever symptoms, a lower hemoglobin level, and current non-pneumonia bacterial infection. Ninety-six percent of the explained variance in physical functioning was accounted for by three symptom complexes: energy/fatigue, neurologic symptoms, and fever symptoms. Significant predictors of energy/fatigue in multivariable models included poorer mental health, lower white blood cell count, longer time since diagnosis, and weight loss (P < 0.01, R2 =.36). Significant predictors of neurologic symptoms included poorer mental health, weight loss, and no zidovudine use (P < 0.001, R2 = .30). Predictors of fever symptoms included poorer mental health, no zidovudine use, weight loss, and history of asthma or chronic obstructive pulmonary disease (P < 0.05, R2 = .25). In conclusion, symptom reports were strong predictors of physical functioning. Poorer mental health and weight loss were correlated consistently with worse symptoms, and not using zidovudine was correlated with worse neurologic and fever symptoms. These variables, and the others the authors identified, may represent mutable determinants of physical functioning in persons with AIDS, and potential targets for specific clinical interventions.

Effects of dietary n-3 fatty acid supplementation in men with weight loss associated with the acquired immune deficiency syndrome: Relation to indices of cytokine production

Cytokines may be involved in weight loss and disturbances of metabolism associated with human immunodeficiency virus (HIV) infection. Dietary n-3 fatty acids reduce the production of interleukin-1 (IL-1) and tumor necrosis factor (TNF) by peripheral blood mononuclear cells (PBMC) in normal humans and prevent IL-1 and TNF anorexia in animals. Accordingly, we studied the nutritional and metabolic effects of a 10-week trial of dietary fish oil (MaxEPA 18 g/day) in men with weight loss due to acquired immune deficiency syndrome (AIDS). Twenty men were enrolled, and 16 completed the 10-week supplementation period. Prior weight loss was 13.7 +/- 1.8 kg(17.4 +/- 1.6% body weight, means +/- SE). Food intake, body composition, blood chemistries, serum cytokine concentrations, in vitro production of IL-1 and TNF by PBMC, and clinical course were followed. A subset of subjects (n=12) underwent stable isotope infusions to measure de novo hepatic lipogenesis (DNL), an in vivo metabolic index that is influenced by cytokine presence and has previously been found to be elevated in AIDS. An unsupplemented group of men with AIDS wasting (10.4 +/- 2.4 kg weight loss, 13.1 +/- 2.2% body weight) was monitored for 10 weeks as controls. Baseline food intake (2,395 +/- 177 kcal/day and 95.1 +/- 7.2 g protein/day), body weight, percent fat, and fat-free mass were unchanged over the 10-week supplementation period. Serum triglycerides were reduced in hypertriglyceridemic subjects, confirming compliance with fish oil supplementation and suggesting that their hypertriglyceridemia was at least in part due to overproduction. Serum TNF and IL-1 were undetectable before or after fish oil supplementation. Serum interferon alpha (IFN) was measurable but did not change. In vitro production of IL-1 and TNF by PBMC was markedly reduced both at baseline and after fish oil supplementation in this population, even in the presence of new AIDS complications, compared with normal controls. The metabolic measurement DNL fell and weight was gained (2.1 +/- 1.3 kg) in subjects who did not develop new AIDS-related complications, but further increases in DNL and further weight loss were observed in subjects who developed a new AIDS complication (p<0.05 for interaction between new complication and change in DNL). No changes in body weight, food intake, serum triglycerides, serum cytokines, or DNL were observed in the unsupplemented group. We conclude that fish oil is a weak anticytokine agent that is unable to overcome the metabolic and nutritional consequences of acute AIDS-related complications but may exert a clinical anticytokine effect in stable AIDS patients. Cytokine production by PBMC is not a useful or reliable marker of in vivo cytokine activity in AIDS patients with weight loss. In contrast, an integrative functional index that is sensitive to cytokine presence in tissues (hepatic DNL) correlated with clinical response. These findings are relevant to the design of future studies of more potent anticytokine agents, such as thalidomide.

Program characteristics of home-delivered meals programs for persons with HIV and AIDS

The nutritional status of persons with HIV and AIDS [PWAs] is constantly challenged throughout the progression of the illness. Home-delivered meals programs for PWAs are rapidly developing across the country to address this problem among the growing population of people with HIV infection and AIDS. This study examined client socio-demographic characteristics (sex, age, ethnicity), types of services offered by these programs, organizational and financial criteria, and characteristics of survey respondents. Data for this study was obtained from 15 of the 17 known home-delivered meals programs for PWAs in the United States through an original, cross-sectional survey instrument conducted by telephone interview between March 1994 and May 1994. Results from this study show an increase in the number of minority populations who participate in these programs (36% African-American and 12% Hispanic vs. 51% Caucasian), as well as women (17.2%) and children (7%). Geographic location was an important determinant for program eligibility. The number of meals served weekly varied greatly (from 510 to 12,600 per week). Other significant services included nutrition counselling, newsletters, and holiday-basket programs. Enhancing service-delivery systems was one of the more prevalent "high-priority" concerns cited, especially with regard to food quality and safety. These results show that these programs are catering increasingly to minority populations, women and children, and that they are expanding their services to meet the growing needs of their client populations. These findings suggest that there is a greater need for meals and other home-based services for persons living with HIV and AIDS.

AIDS in Africa

HIV has infected more than 10 million people in sub-Saharan Africa with prevalence rates of up to 30% reported from some countries. Adult transmission of HIV in Africa is mainly heterosexual and over half of new infections are in women. About 40% of infants born to HIV-positive mothers are themselves infected. Diarrhoea occurs in 90% of African AIDS patients and 'slim disease' (prolonged diarrhoea and wasting usually due to coccidian parasites) is pathognomic of AIDS in Central Africa. Dual infection with HIV and tuberculosis is a major problem. African AIDS patients appear to succumb to virulent pathogens, especially Mycobacterium tuberculosis, before they become sufficiently immunosuppressed to develop the opportunistic infections typically associated with advanced HIV disease in developed countries.

Regulation of human immunodeficiency virus type 1 and cytokine gene expression in myeloid cells by NF-kappa B/Rel transcription factors

CD4+ macrophages in tissues such as lung, skin, and lymph nodes, promyelocytic cells in bone marrow, and peripheral blood monocytes serve as important targets and reservoirs for human immunodeficiency virus type 1 (HIV-1) replication. HIV-1-infected myeloid cells are often diminished in their ability to participate in chemotaxis, phagocytosis, and intracellular killing. HIV-1 infection of myeloid cells can lead to the expression of surface receptors associated with cellular activation and/or differentiation that increase the responsiveness of these cells to cytokines secreted by neighboring cells as well as to bacteria or other pathogens. Enhancement of HIV-1 replication is related in part to increased DNA-binding activity of cellular transcription factors such as NF-kappa B. NF-kappa B binds to the HIV-1 enhancer region of the long terminal repeat and contributes to the inducibility of HIV-1 gene expression in response to multiple activating agents. Phosphorylation and degradation of the cytoplasmic inhibitor I kappa B alpha are crucial regulatory events in the activation of NF-kappa B DNA-binding activity. Both N- and C-terminal residues of I kappa B alpha are required for inducer-mediated degradation. Chronic HIV-1 infection of myeloid cells leads to constitutive NF-kappa B DNA-binding activity and provides an intranuclear environment capable of perpetuating HIV-1 replication. Increased intracellular stores of latent NF-kappa B may also result in rapid inducibility of NF-kappa B-dependent cytokine gene expression. In response to secondary pathogenic infections or antigenic challenge, cytokine gene expression is rapidly induced, enhanced, and sustained over prolonged periods in HIV-1-infected myeloid cells compared with uninfected cells. Elevated levels of several inflammatory cytokines have been detected in the sera of HIV-1-infected individuals. Secretion of myeloid cell-derived cytokines may both increase virus production and contribute to AIDS-associated disorders.

Small intestinal manifestations of HIV infection

The small intestine is a common site of involvement in patients infected with the human immunodeficiency virus (HIV). Although there are numerous mechanisms by which small intestinal disease may occur in HIV infected patients, the resulting clinical manifestations of these disorders are remarkably similar and include the development of diarrhoea, weight loss and nutrient deficiencies. In fact, the original designation of AIDS in African countries as the 'slim disease' underlines the importance of small intestinal involvement (most likely secondary to parasitic infections) which commonly occurs in Third World Countries. The current review will provide a clinically oriented overview of small intestinal disease in patients infected with HIV. Because specific data on treatment of small intestinal diseases in AIDS is often lacking, some presented information is based on the author's experience and opinions.