Aspects of gastrointestinal immunology and nutrition in human immunodeficiency virus-1 infection in Brazil.

Mucosal surfaces have a fundamental participation in many aspects of the human immunodeficiency virus (HIV) infection pathogenesis. In Brazilian HIV-1 infected subjects, loss of weight and appetite are among the most debilitating symptoms. In this review we describe a defined mucosal immunogen that has profound but transient effects on HIV viral load, and we suggest that gut associated lymphoid tissue under constant immunostimulation is likely to provide a major contribution to the total levels of HIV. We also show that hypermetabolism appears to play a role in the wasting process in Brazilian patients coinfected with HIV and tuberculosis.

Surrogate markers of disease progression in HIV-infected children in Rio de Janeiro, Brazil.

In order to test the predictive value of immune complex-dissociated p24 antigenaemia (ICD-p24Ag), beta 2 microglobulin (beta 2-M), and neopterin as markers of disease progression, 53 HIV-1 infected children (mean age 68 months) and nine HIV-negative controls (mean age 65 months) were studied prospectively for 9 months. Five were classified in category E (CDC-1994) and seroreverted during the study, 14 in category A, nine in category B, and 25 in category C (CDC-1994). Blood samples were taken at medium intervals of 61 days and tested for ICD-p24Ag, beta 2 microglobulin, and neopterin. The results were correlated with clinical outcome and CD4-lymphocyte counts. All three groups (A, B, C) of symptomatic children had similar positivity in an ICD-p24Ag test (48.1, 58.8, and 51.0 per cent, respectively), and all in group E had negative p24 antigenaemia. beta 2 microglobulin and neopterin tests showed no correlation with clinical stages of HIV-1 infection. There was no significant correlation between these three tests with age-matched CD4 lymphocyte counts (p > 0.05). In contrast, the CD4 lymphocyte count correlated well with disease stages. These data suggest that the markers evaluated in the present study do not correlate well with clinical findings or with CD4 lymphocyte counts. Of all the markers tested, CD4 count was the best to predict prognosis of HIV disease in this cohort.

Impact of tuberculosis on the body composition of HIV-infected men in Brazil.

OBJECTIVE: Tuberculosis (TB) is the commonest HIV-related opportunistic infection in many developing countries and is thought to be a frequent underlying cause of HIV-associated wasting. We have used reference water dilution methods to examine the body composition changes associated with TB and to assess the severity and pattern of wasting. METHODS: The study was conducted at a charitable support house for poor and homeless HIV-infected people in Rio de Janeiro, Brazil. Male patients who were HIV-positive and receiving treatment for active TB (HIVTB+) and HIV-infected controls without TB (HIVTB-) were studied. Total body water (TBW) and extracellular water (ECW) were measured by giving oral doses of deuterium oxide and sodium bromide, respectively, and determining enrichment in plasma after 4 hours. Intracellular water (ICW), body cell mass (BCM), lean body mass (LBM) and fat mass were calculated from these parameters using standard equations. RESULTS: HIVTB+ (n = 11) and HIVTB- (n = 12) groups were similar in age, height, CD4 count and HIV risk factors. HIVTB+ men had significantly lower mean ICW (13.2 versus 16.6 kg; p = .02) and BCM (18.4 versus 23.0 kg; p = .02), a relative expansion of ECW (35.0 versus 30.0 L/kg body weight; p = .04), and small and nonsignificant reductions in total body weight (58.0 versus 62.1 kg; p = .26), LBM (45.5 versus 47.7 kg; p = .33) and fat mass (12.5 versus 14.4 kg; p = .51) compared with HIVTB- controls. BCM in the HIVTB+ group was similar to reference values for severe malnutrition. The relative depletion of BCM appeared excessive in comparison with reference values for uncomplicated starvation. CONCLUSION: The nutritional status of HIVTB+ patients was significantly worse than HIVTB- patients. Body weight and LBM underestimated the nutritional deficit, and measurement of BCM is therefore necessary to appreciate the extent of malnutrition in such patients. Malnutrition in HIVTB+ patients is severe and may therefore contribute to decreased survival. Hypermetabolism appears to play a role in the wasting process in patients coinfected with HIV and TB.

PIP: This paper examines the impact of tuberculosis (TB) on the body composition of HIV-positive men with treatment for active TB (HIV/TB+) and HIV-infected men without TB (HIV/TB-) in Brazil. Total body water (TBW) and extracellular water (ECW) were measured by giving oral doses of deuterium oxide and sodium bromide, respectively, and determining the enrichment in plasma after 4 hours. Calculated from these parameters are the intracellular water (ICW), body cell mass (BCM), lean body mass (LBM) and fat mass. Age, height, CD4 count and HIV risk factors were similar among HIV/TB+ (n = 11) and HIV/TB- (n = 12). HIV/TB+ patients had significantly lower mean ICW (13.2 vs. 16.6 kg) and BCM (18.4 vs. 23 kg), a relative expansion of ECW (35 vs. 30 l/kg body weight, nonsignificant reductions in TBW (58 vs. 62.1 kg), LBM (45.5 vs. 47.7 kg) and fat mass (12.5 vs. 14.4 kg) compared with HIV/TB- men. Nutritional status was found to be significantly worse among HIV+ patients. Malnutrition was also severe in HIV/TB+ patients, which contributed to a decreased life span. Hypermetabolism appears to play a role in the wasting process of patients with HIV and TB. To improve physical function, quality of life, and survival among HIV-infected patients with TB, optimization of nutritional status should be at the core of treatment.

Increase in plasma viral load after oral cholera immunization of HIV-infected subjects.

OBJECTIVE: Constant antigenic stimulation of the large immune cell population contained within gut-associated lymphoid tissue during HIV infection may contribute to patients' total viral load. The aim of this investigation was to evaluate the effect of a mucosal antigenic challenge on HIV replication. DESIGN: Prospective clinical study. METHODS: Twelve HIV-1-infected men (mean age, 42.3 years) from the Casa de Apoio Santo Antonio, Rio de Janeiro, Brazil, were immunized with combined whole cell-toxin B subunit oral cholera vaccine. Blood was collected on days 0, 2, 4, 6, 10 and 15 after immunization and plasma was tested for cholera toxin-specific antibody response (IgG and IgA), beta2-microglobulin, and plasma viral load. CD4 lymphocyte counts were performed within 1 week before immunization. Five HIV-infected non-immunized individuals were studied as controls. RESULTS: There were no adverse effects following immunization and no deterioration in clinical outcome during 3 months of follow-up. A transient increase in viral load that ranged from twofold to 60-fold was observed in all cases and was statistically significant on days 2, 6 and 10 (P = 0.017, P = 0.025, P = 0.021, respectively). There was no correlation with CD4 cell counts. None of the non-immunized subjects demonstrated the pattern of viraemia observed after immunization (P > 0.10 on all days). CONCLUSIONS: Our data indicate that mucosal immunization with oral cholera vaccine induces a transient increase in HIV viraemia, regardless of clinical stage of infection and CD4 cell counts. These findings suggest that mucosal stimulation of HIV-infected patients enhances HIV replication.

Immunization of persons with HIV infection and other secondary immunodeficiencies.

Patients with secondary immunodeficiencies are at a high risk of infection. Currently some of these infections are preventable through specific immunization. Prevention of these diseases can diminish morbidity and mortality amongst these patients. In this review we describe the use of vaccines in persons with secondary immunodeficiencies.

Imaturidade imunológica fetal e neonatal: implicaçöes na evoluçäo clínica da infecçäo pelo HIV-1 em crianças / Immunologic fetal and neonatal immaturity: influence on the clinical evolution of HIV-1 infection in chindren

Crianças infectadas pelo HIV-1, por via vertical, apresentam uma evoluçao clínica mais grave do que crianças infectadas por outras vias e adultos. A imaturidade fisiológica dos sistemas imunitários fetal e neonatal, no momento da infecçao, parece ter papel crucial na progressao da infecçao pelo HIV-1 em crianças. Neste artigo, fazemos revisao da ontogenia do sistema imunológico humano, correlacionando-a com a imunopatogenia da síndrome de imunodeficiência adquirida (AIDS), em crianças infectadas por transmissao vertical, em suas diferentes fases.

[Immunologic fetal and neonatal immaturity: influence on the clinical course of HIV-1 infection in children]. / Imaturidade imunológica fetal e neonatal; implicações na evolução clínica de infecção pelo HIV-1 em crianças.

Children born to HIV-1 infected mothers present a more severe clinical evolution than adults or children infected by other routes. The physiologic immaturity of the fetal and neonatal immune systems at the time of the infection probably plays an essential role in the progression of HIV-1 infection in these children. This paper describes the development of the normal human immune system and its correlation with the immunopathogenicity of vertical acquired immunodeficiency syndrome (AIDS).

Mucosal immunology and models of mucosal HIV infection

The mucosa associated lymphoid tissue regulates and coordinates immune responses against mucosal pathogens. Mucosal tissues are the major targets exposed to HIV during transmission. In this paper we describe in vitro models of HIV mucosal infection using human explants to investigate target cells within this tissue.

Mucosal immunology and models of mucosal HIV infection.

The mucosa associated lymphoid tissue regulates and coordinates immune responses against mucosal pathogens. Mucosal tissues are the major targets exposed to HIV during transmission. In this paper we describe in vitro models of HIV mucosal infection using human explants to investigate target cells within this tissue.